ResearchPad - cardiovascular-endocrinology https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[SUN-LB96 Basal Contralateral Aldosterone Suppression Is Rare in Lateralized Primary Aldosteronism and Can Be Useful in Predicting Surgical Outcome]]> https://www.researchpad.co/article/elastic_article_9554 Background: Adrenal venous sampling (AVS) is performed to distinguish between unilateral or bilateral source of aldosterone in primary aldosteronism (PA). Unilateral aldosteronomas should lead to suppression of renin and contralateral (CL) aldosterone secretion, assessed by the CL suppression ratio. We recently found that CL aldosterone suppression was relatively rare using the ratio of basal aldosterone concentration of the opposite adrenal vein/periphery (AOPP/AP) in contrast to the traditional cortisol-corrected aldosterone ratio ((A/C)OPP(A/C)P). Pathology studies showed frequent zona glomerulosa (ZG) hyperplasia adjacent to a dominant aldosteronoma, which could also indicate probable ZG hyperplasia in the CL adrenal. The ratio of basal CL suppression could be a usefull parameter to predict cure following unilateral adrenalectomy (UA), but controversy remains in the literature.

Objectives:

1. To evaluate the prevalence of basal CL suppression using the AOPP/AP ratio as compared to the (A/C)OPP/(A/C)P ratio at previously established cut-offs.

2. To determine the best cut-off to predict clinical and biochemical surgical cure in two Canadian referral centers.

3. To compare the accuracy of the AOPP/AP ratio to the basal lateralization ratio (LR) and the post-ACTH LR in predicting the surgical outcome.

Methods: 330 patients with PA and successful bilateral simultaneous basal and post-ACTH stimulated AVS (selectivity index >2 basally and >5 post-ACTH) were included; 124 patients found to be lateralized underwent UA. The follow-up data were evaluated for clinical and biochemical cure at 3 and 12 months using the PASO criteria.

Results: Using AOPP/AP and (A/C)OPP/(A/C)P at the cut-off of 1, the prevalence of CL suppression is 6% and 45%, respectively. The median CL suppression ratio is 2.3 (1.3-5.1) in lateralized cases of PA using AOPP/AP. Using ROC curves, the AOPP/AP ratio is associated with clinical cure at 3 and 12 months and biochemical cure at 12 months. (A/C)OPP/(A/C)P is associated with biochemical cure only. The cut-offs for AOPP/AP offering the best sensitivity and specificity for clinical and biochemical cures at 12 months are 2.15 (Se 63% and Sp 71%) and 6.15 (Se 84% and Sp 77%), respectively. Basal LR and post-ACTH LR are associated with clinical cure but only the post-ACTH LR is associated with biochemical cure.

Conclusions: Basal CL suppression defined by the AOPP/AP ratio is rare and incomplete compared to the traditional (A/C)OPP/(A/C)P ratio in lateralized cases of PA. This may reflect the frequent micronodular hyperplasia adjacent to dominant aldosteronomas and possibly in the CL adrenal. Basal CL aldosterone suppression may predict clinical postoperative outcome, but with modest accuracy.

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<![CDATA[SAT-567 Hypertriglyceridem...From Mild to Fatal!... Is Time for Awareness]]> https://www.researchpad.co/article/elastic_article_8800 Hypertriglyceridemia… From mild to fatal! … Is Time for Awareness.

Hypertriglyceridemia can be primary or acquired. High triglycerides are related to complications such as pancreatitis and there is a positive correlation between hypertriglyceridemia and atherosclerotic burden. In this case series we aim to discuss pancreatitis as a hypertriglyceridemia complication and to acknowledge the importance of prevention and management. Is there something we can do to raise awareness and avoid complications as in the cases?

All cases present with chief complaint of epigastric cramp-like abdominal pain, radiating to the back, nausea/vomiting and with highly lipemic blood samples.

38y/o F admitted after been found with lipase 268 U/L (n<60 U/L), amylase 131 U/L (n<100 U/L) and findings of pancreatitis on CT scan. Patient with one-year history of T2DM refers this is the 4th episode of pancreatitis and reports that last time she was told about having triglycerides in 4,000 mg/dL for which she went to her physician that prescribe her Fenofibrate. Patient triglycerides were 7,931 mg/dL (n<199 mg/dL) and found with poorly controlled diabetes with HgbA1c 8.4%. She was properly managed, and triglycerides decrease to 1,309 mg/dL.

31y/o F with elevated lipase (237 U/L, n<60 U/L) and findings of pancreatitis on CT scan was admitted and found with 7,755 mg/dL triglycerides. She refers to have endometriosis for which she uses OCPs for >5years. She develops intractable abdominal pain along with abdominal distension and progress to Acute Respiratory Distress Syndrome (ARDS) requiring mechanical ventilation. She had a prolonged ICU stay and after management triglycerides decrease to 95mg/dL, symptoms resolve, and patient was discharge.

48y/o F with pancreatitis, lipase levels 1,452 U/L, amylase 744 U/L and positive imaging findings. Patient with uncontrolled diabetes (HgbA1c 11.0%) and breast mass s/p lumpectomy for which she used tamoxifen for the last 2 years. Triglycerides 7,444mg/dL on Gemfibrozil started due to previous levels found >4,000 mg/dL on outpatient evaluation. She deteriorates clinically and develops renal failure, abdominal compartment syndrome, respiratory distress and hypotension requiring mechanical ventilation and vasopressors. On repeated abdominal CT pancreas changes were suggestive of fulminant pancreatitis. Patient did not respond to treatment and passed away 48 hours after admission.

Hypertriglyceridemia complications can be mild or fatal as in these cases. They were evaluated by a primary care physician before complications occur and had secondary causes that predispose them to hypertriglyceridemia, but they were not addressed, reason for which these scenarios raise concern of how much we know? How much we are doing to prevent these outcomes?... Awareness of hypertriglyceridemia management and adverse effects is necessary to avoid complications and fatal outcomes. Is time!

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<![CDATA[SAT-LB92 Sex Hormones Therapy Differentially Modulates HDL Function in Transgender Individuals]]> https://www.researchpad.co/article/elastic_article_8791 Background/aim: The main proposed atheroprotective function of high-density lipoproteins (HDL) lays on their role to promote macrophage cholesterol efflux. An insightful way to learn more about the effects of sex hormones on HDL function is to study changes during hormone therapy. The present study was aimed at evaluating the effects of exogenous sex hormones administration on HDL cholesterol efflux capacity (CEC) within transgender individuals. CEC estimates the ability of HDL to remove cholesterol from cells, i.e. the initial step in reverse cholesterol transport.

Subjects/Methods: Transmen were treated with testosterone gel, a mix of testosterone esters once every three weeks) or testosterone undecanoate once every twelve weeks, whereas transwomen were treated with either oral estradiol valerate or a transdermal application of estradiol (patches). Cyproterone acetate was prescribed as a testosterone-blocking agent to all transwomen. HDL function was evaluated by a radioisotopic technique. Hormone levels, lipids and HDL function were evaluated after one year of follow-up.

Results: In transmen (n= 15), testosterone markedly increased (+ 97%; p < 0.0001), whereas luteinizing hormone (LH) decreased significantly (- 64%; p = 0.049). Total cholesterol and low-density lipoprotein cholesterol (LDL-C) were not affected by testosterone treatment, whilst triglycerides (TG) were raised (+ 11.76%; p = 0.0078) and HDL-C reduced (- 19.6%, p=0.0103). Concerning HDL CEC, only the aqueous diffusion process was lowered (- 9.8%; p = 0.0032), an effect directly correlated with HDL-C changes (r = 0.6242, p = 0.0002). Total-, ATP-binding cassette transporter (ABCA1)-, and ABCG1-mediated CEC were not affected by testosterone treatment. In transwomen (n= 15), estradiol levels were raised (+200%, p=0.013) whereas LH and testosterone significantly reduced, i.e. - 97% for both. Relative to lipids, estradiol supplementation reduced total cholesterol (- 10.7%, p=0.0017), HDL-C (- 14.3%, p = 0.0024) and LDL-C (- 10.9%, p = 0.0058). Total HDL CEC decreased (- 11%, p=0.0001) with a specific decrement in CEC mediated by the ATP-binding cassette transporter (ABCA1) (-24%, p = 0.0003) and aqueous diffusion (-4.7%, p = 0.0014). This last was associated to a reduction in HDL-C (r = 0.4084, p = 0.0251). Conversely, the drop in ABCA1 and total CEC did not associate to reductions in HDL-C levels.

Conclusions: In transmen, testosterone supplementation was associated with a reduction in aqueous diffusion-mediated CEC, an effect potentially dependent to HDL-C changes. In transwomen, estrogen significantly decreased HDL function (CEC), independent of HDL-C levels changes.

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<![CDATA[SAT-553 Use of Optimal Cutting Temperature Compound (OCT)-Embedded Adrenal Tumor Tissue for Intratumoral Steroid Hormone Profiling]]> https://www.researchpad.co/article/elastic_article_8775 Background: Primary aldosteronism (PA) is the most common cause of secondary hypertension, accounting for 5-8% of all hypertension. PA is most commonly attributed to an aldosterone-producing adenoma (APA) or to bilateral hyperaldosteronism (BHA). Mutations in the inward-rectifying K+ channel (mKCNJ5), which increase autonomous aldosterone production, are most frequently detected in APAs. APAs with mKCNJ5 display aberrant expression of aldosterone synthase (CYP11B2) and 17α-hydroxylase (CYP17A1), which are involved in aldosterone and cortisol synthesis, respectively. Co-expression of these enzymes results in the production of a set of “hybrid” steroids, which have been proposed as serum biomarkers. The relative production of hybrid steroids in adrenal tumors vs. adjacent normal adrenal (NA) tissue has not been investigated. Objectives: To determine the utility of OCT-embedded adrenal tumor tissue for steroid profiling. To use immunohistochemistry (IHC)-guided OCT tumor capture for intratumoral hybrid steroid profiling in mKCNJ5 APA and NA tissue. Methods: OCT-embedded adrenal tissue from 9 patients (8 women, Age 45.9 ± 3.3 years) with APAs harboring known KCNJ5 mutations were used for the study. Where available OCT-embedded normal adrenal (NA) tissue adjacent to APAs were used as controls (n=4). IHC was performed for CYP11B2 and CYP17A1 on OCT tissue allowing guided APA capture from serial sections. Steroids were extracted from APA and adjacent NA tissue, and quantified by liquid chromatography/tandem mass spectrometry. Steroids measured were normalized to the protein content of the extracted tissue. Results: Compared to NA, APA tissue demonstrated 23-, 5.6- and 6.4-fold higher levels of aldosterone, 11-deoxycorticosterone, and 18-hydroxycorticosterone, respectively (P<0.05). In addition, the “hybrid” steroid products, 18-oxocortisol and 18-hydroxycortisol, were significantly elevated in APA vs. NA (P<0.01). Conversely, the adrenal androgens dehydroepiandrosterone and 11-hydroxyandrostenedione were lower in APA as compared with NA (P<0.05). All mKCNJ5 APAs were also found to co-express CYP11B2 and CYP17A1. Conclusion: IHC-guided mKCNJ5 APA capture and steroid extraction identified a distinct intratumoral hybrid steroid signature that associated with co-expression of CYP11B2 and CYP17A1.These findings also demonstrate that OCT-embedded tissue can be used to accurately define intra-tissue steroid profiles, which will have application for steroid-producing and steroid-responsive tumors.

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<![CDATA[SAT-559 Patients with Hyperaldosteronism Have Higher Prevalence of Obstructive Sleep Apnea. From the National Inpatient Sample]]> https://www.researchpad.co/article/elastic_article_8738 Introduction: Previous studies suggested that aldosterone excess may worsen obstructive sleep apnea (OSA) through causing peri-pharyngeal edema. Objective: In this study we sought to examine if hyperaldosteronism is associated with OSA. Methods: The National Inpatient Sample (NIS) data was queried for adults with diagnosis of primary and secondary hyperaldosteronism during the years 2012 - 2015. Patients with hyperaldosteronism were identified using the international classification of disease (ICD-9). Each patient who was diagnosed with hyperaldosteronism was matched to randomly selected controls at a 1:4 ratio by age, gender and year of hospitalization. A multivariable logistic regression model was used to estimate the adjusted odds ratio (aOR) of OSA among patients with hyperaldosternoism. We adjusted for patient demographics, socioeconomic factors, hospital factors and clinical comorbidities. Subgroup analysis was performed based on gender, race and age groups; young adults (aged 18–35 years), middle aged (> 35-<55 years) and older adults (aged > 55 years). Results: There were 23,465 patients diagnosed with hyperaldosteronism identified. The mean age was 59 (standard error of the mean (SEM): 0.1. Females represented 48.5%. Compared to control, patients with hyperaldosteronism had higher prevalence of hypertension, CHF, stroke, obesity, diabetes, renal failure and lower prevalence of tobacco use and COPD. The proportions of African Americans were higher among patients with hyperaldosteronism compared to the control 30.1 vs 15.5, p<0.001. Patients with hyperaldosteronism had higher prevalence of OSA 16.4 vs 8.3, p<0.001. On multivariate analysis, hyperaldosteronism was independently associated with higher odds for OSA with aOR 2.01 (95%CI: 1.81–2.23) p<0.001. On subgroup analysis, similar findings were observed irrespective of gender, age group or race. Conclusion: Prevalence of OSA is higher among patients with hyperaldosteronism. Physicians may need to consider a case detection of hyperaldosteronism in patients with OSA and hypertension. Similarly we suggest to evaluate patients with hyperaldosteronism for OSA.

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<![CDATA[SUN-574 A1AT: Novel Inhibitor of Active PCSK9]]> https://www.researchpad.co/article/elastic_article_8679 Heart disease is the principal cause of death and disability for both men and women in the US, accounting for 40% of all annual deaths. African American populations are disproportionately burdened with metabolic diseases, due in part to cholesterol metabolism deficiencies. Elevated low density lipoprotein (LDL) cholesterol levels and inflammation promote atherogenic conditions which lead to heart disease. Proprotein convertase subtilisin/kexin-9 (PCSK9) is a biomarker which enhances athrogenic progression by controlling the number of LDL receptor molecules expressed at the plasma membrane. PCSK9 indirectly regulates LDL-cholesterol levels. Previous reports show some patients do not respond well to general anti-cholesterolemic treatments. We believe this is due to altered PCSK9 activity, which is currently not being evaluated. We have developed a novel assay to detect active PCSK9. A1AT is a SERPIN family member whose primary objective is inhibition of proteases. Specific levels of A1AT are required to maintain metabolic homeostasis. Based on this, we hypothesized that a specific ratio between A1AT serum levels and PCSK9 activity levels would eliminate statin intolerance/resistance, regulating LDL-cholesterol metabolism congruently. Using this novel active PCSK9 detection assay, we provide evidence that A1AT interacts with PCSK9 in the medium of C3A hepatic-like cells, preventing the formation of PCSK9/LDL receptor complexes in vitro. There was an approximate 20% inhibition in PCSK9-LDL receptor complex formation when liver cells were treated with recombinant A1AT (rA1AT). A dose dependent response analysis proved 200ng/ml of rA1AT had an 46% reduction in PCSK9 activity. We determined PCSK9 activty and A1AT levels correlate with key diabetic factors in humans, suggesting that A1AT could effect diabetes progression.

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<![CDATA[SAT-LB95 Low Density Lipoprotein Receptor and Proprotein Convertase Subtilisin/Kexin Type 9 Kinetics Using Heavy Water (2H2O) Labeling and Mass Spectrometry]]> https://www.researchpad.co/article/elastic_article_8654 Abnormally high blood cholesterol levels in low density lipoprotein (LDL) increases the risk of heart disease. Cell surface receptors such as LDL-receptors (LDLr) regulate the clearance of LDL from blood circulation. As cholesterol levels decrease, cells promote cholesterol synthesis and cholesterol uptake by increasing LDLr expression. Another regulatory protein of plasma cholesterol clearance is proprotein convertase subtilisin/kexin type 9 (PCSK9). It is secreted from the liver into circulation where it can bind to and target LDLr to the lysosome for subsequent degradation. The current model of cholesterol regulation describes how increased cholesterol content down-regulates the number of LDLr promoted by PCSK9 mediated degradation, however minimal knowledge is not known about LDLr and PCSK9 kinetics using heavy water labeling, and how cholesterol enriched diet affects LDLr and PCSK9 kinetics in vivo. Therefore, our objective(s) were to establish a method 1) to measure the kinetics of LDLr and PCSK9 via stable isotopic metabolic labeling with heavy water (2H2O) in vivo 2) to further test established models of cholesterol metabolic regulation on LDLr and PCSK9 turnover after feeding mice a cholesterol enriched diet. We hypothesize that a cholesterol enriched diet will decrease both LDLr and PCSK9 synthesis rates. In order to test this, mice were fed a cholesterol enrich diet for 1 week and metabolically labeled with heavy water (2H2O) up to 36 hours. LDLr and PCSK9 were immunoprecipitated from liver and deuterium incorporation into LDLr and PCSK9 were measured via mass spectrometry. Our results revealed high cholesterol feeding down-regulated cholesterol synthesis and LDLr fractional synthesis rate decreased from 10.0% to 6% per hour. PCSK9 concentration also decreased from 1 to 0.2 (ng/ml / total mg protein), but the synthesis rate increased from 9.0%/day in control mice to 19.5%/day in high cholesterol diet. These results suggest high cholesterol feeding increases PCSK9 synthesis that potentially depletes the intracellular pool to target LDLr to the lysosome thus decreasing LDLr turnover. This research provides a flux-based approach to measure the kinetics of LDLr and PCSK9 for a molecular based kinetic insight of their functions in physiology, disease and therapy.

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<![CDATA[SAT-573 Eruptive Xanthomas in a Patient with Hypertriglyceredemia and Type 2 Diabetes Mellitus]]> https://www.researchpad.co/article/elastic_article_8647 BACKGROUND: Eruptive xanthomas are rare, asymptomatic, cutaneous lesions and are markers for serious underlying metabolic disorders that demand an early diagnosis to prevent morbidity and mortality.

Clinical Case: A 27 years old obese female presented with generalized, pruritic eruptions. The eruptions had been present for approximately three weeks. Crops of firm yellow-red circumscribed Papules (diameter 1–3 mm) distributed on the extensor surfaces of both the upper and the lower extremities which were few in numbers to begin with but increased in density subsequently spreading to involve her back, abdomen, knees, and posterior thighs. The patient besides being obese had no other significant past medical or family history. Labs: FBS:258 mg/dl (80-100mg/dl), HbA1c:11.7%(<5.6%), Total lipids: 3680 mg/dl (400–1000 mg/dl), Total Cholesterol: 857 mg/dl (120–200 mg/dl), Triglycerides: 5428 mg/dl (70–150 mg/dl), HDL:15mg/dl (45–64 mg/dl), LDL: 371 mg/l(<130 mg/dl),VLDL: 402 mg/dl (<30 md/dl). Results of kidney, liver and thyroid function tests were normal, as well as amylase and lipase. X-ray chest and abdominal ultrasound were unremarkable. Biopsy of the papules was not carried out due to non-affordability on the part of the patient. The patient was managed by an interdisciplinary approach for diabetes mellitus type 2 and hyperlipidaemia. Treatment was started with oral hypoglycaemic along with lipid lowering agents and the required lifestyle modifications including weight control, adopting a low-fat diet, and regular exercise were advised. The papules resolved within six weeks of the treatment and lab reports indicated improvement in her glycemic control and hypertriglyceridemia. It was clinically diagnosed as Eruptive Xanthomas of secondary hypertriglyceridemia due to diabetes mellitus.

CONCLUSION:

Recognizing eruptive xanthomas and being aware of its association with hypertriglyceridemia and diabetes mellitus can help to decrease any lag between a patient being seen by a physician and treatment for a serious medical conditions such as coronary artery disease and pancreatitis.

REFRENCES: Digby M; Belli R; McGraw T; Lee A (2011). “Eruptive xanthomas as a cutaneous manifestation of hypertriglyceridemia: a case report”. J Clin Aesthet Dermatol. 4: 44–6. PMC 3030216Freely accessible. PMID 21278899.

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<![CDATA[SAT-577 Severe Asymptomatic Hypertriglyceridemia]]> https://www.researchpad.co/article/elastic_article_8609 Background

Case reports of patients with severely elevated serum triglyceride levels (>1000 mg/dL) have been documented where Insulin infusions, heparin and plasmapheresis have demonstrated rapid and successful decrease in serum Triglyceride levels. The benefits of one approach versus the other to prevent major complications such as cardiovascular events or acute pancreatitis has not been well investigated. We present the case of a patient with severely elevated serum triglyceride levels without any manifestations.

Case Description

A 53-year-old male presented from his primary care provider’s office due to elevated Triglycerides levels over 6000 as per outpatient lab work. Inpatient labs were unattainable initially due to hemolysis secondary to the severely high lipid content. Patient was admitted to the medical ICU for closer monitoring and initiated on an insulin drip. Two days after insulin initiation patient’s triglyceride levels returned as 2,887 with a total cholesterol count of 848. His insulin drip was continued until his TAG levels were less than 1000. Upon discharge his levels were less than 600.

Discussion

Most patients with hypertriglyceridemia are asymptomatic. However, in patients with levels above 1000 mg/dL, the risk of pancreatitis or cardiovascular event is of concern. Hypertriglyceridemia may account for 1 to 14 percent of cases of acute pancreatitis. Treatment is largely based upon symptoms and complications. In the event of pancreatitis or other cardiovascular complication, plasmapheresis is usually recommended. If asymptomatic, Insulin may be used. Insulin promotes synthesis of lipoprotein lipase which functions to hydrolyze triglycerides, and has been shown to be an effective lowering agent in the treatment of such individuals. Case reports of Heparin being used as a lipid lowering agent have also been documented, but was not used in our particular patient.

Normal triglyceride plasma levels are defined as less than 150 mg/dL. Mild hypertriglyceridemia typically ranges between 150-499 mg/dL, moderate between 500-866 mg/dL, and severe is defined as levels greater than 886 mg/dL. Plasma triglyceride levels above 1000 mg/dL occur in fewer than 1 in 5000 individuals. It is said that patients with TAG levels above 2000 mg/dL almost always have both a secondary and a genetic form of Hypertriglyceridemia. For this reason it is very important to identify these patients as early as possible to treat appropriately. Our patient was a known alcohol abuser, yet without the presence of some polygenic familial disorder, the likelihood of our patient having TAG levels >6000 mg/dL, is very unlikely.

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<![CDATA[OR34-04 Efficiency of Adrenal Venous Sampling in the Treatment Choice of Primary Aldosteronism (AVSTAT Study)]]> https://www.researchpad.co/article/elastic_article_8567 BACKGROUND: Adrenal venous sampling (AVS) is strongly recommended for a subtype diagnosis of primary aldosteronism (PA) if adrenalectomy (ADX) is desired by the patient. Given various issues related to AVS such as technical demand, invasive nature, expensive cost and radiation exposure, AVS is expected to lead efficiently to the subtype diagnosis and ADX. Aim: Primary objective was to assess the performance of AVS to determine treatment of PA by investigating the ratio of unilateral disease and rate of ADX following AVS in patients with unilateral disease. Methods: Sixteen major referral centers in ENS@T (n=10) and Japan (n=6) participated in the study. Study period was from 2006 to 2018. Data on total number of PA patients, AVS (total number and number of successful procedures), number of patients with unilateral diseases, and number of patients that underwent ADX were collected by a questionnaire-based survey. In addition, reasons for not proceeding to ADX in patients with a unilateral diagnosis were investigated. The diagnosis of PA was based on the positive case detection and at least one positive result in confirmatory testing. Results: Total number of confirmed PA patients and conducted AVS showed a dramatic increase during the past decade (PA: 1061 pts/ 2006–2011 to 3718 pts/ 2012–2018; AVS: 720/ 2006–2011 to 2448/ 2012–2018). Success rate of AVS was improved from 79.0% (2006–2011) to 92.5% (2012–2018). Both rate of unilateral PA and ADX of successful procedures decreased from 42.7% (2006–2011) to 37.3% (2012–2018) and from 40.8% (2006–2011) to 34.9% (2012–2018), respectively. Of the patients with successful AVS, bilateral disease was diagnosed in 63.5% (1812/2854 pts). Of the unilateral PA patients, 11.9% (125/ 1054 pts) were not subjected to ADX. The rate of the patients not subjected to ADX was significantly higher in Japan than in ENS@T centers both in patients with successful AVS (75.8% vs. 53.4%) and with unilateral disease (19.9% vs. 8.6%). Clinical decision against ADX in unilateral disease was made by the physicians in 33.3%, the patients in 33.3%, and both in 33.3%. Medical factors for Dr.’s decision against ADX in unilateral disease included good blood pressure control, normokalemia, comorbidities (e.g. DM, CKD), non-lateralized CT findings (e.g. no tumor, contralateral tumor), and discordant results among different criteria of AVS.

Conclusions: High prevalence of bilateral disease and change of treatment policy after implementation affected the efficiency of AVS as an essential diagnostic procedure prior to ADX. Development of non-invasive procedures to exclude bilateral PA and more strict indication of AVS are warranted.

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<![CDATA[SAT-578 A Rare Case of Laboratory Hypertriglyceridemia: Glycerol Kinase Deficiency]]> https://www.researchpad.co/article/elastic_article_7175 Background: Hypertriglyceridemia (HTG) is common; however, pseudo-HTG due to high glycerol in glycerol kinase deficiency (GKD, MIM: 307030) is a rare cause of HTG that need to be delineated for appropriate management. GKD is an X-linked recessive disorder characterized by hyperglycerolemia and glyceroluria. Two of three GKD subtypes are known as “isolate” GKD due to a mutation in GK gene alone: (1) symptomatic juvenile form, and (2) benign adult form, associated with an incidental finding of HTG.

Since most commercial laboratories determine triglyceride (TG) levels by a glycerol measurement, TG-backbone, patients with GKD are mistakenly labelled as having HTG. Glycerol-blanking is required to reveal the actual TG, but it is costly. Since usual TG-lowering medications are ineffective or even harmful, novel methods to screen for individuals with GKD or pseudo-HTG are necessary.

Objective: Through identification of a clinical case of GKD that was diagnosed by glycerol-blanking, we are proposing two potential methods to screen for pseudo-HTG, and presenting their reliability.

Methods: The patient was recruited into an IRB-approved study investigating etiologies of dyslipidemia at the University of Pennsylvania. Patient provided consent for medical record review.

Results: A 49-year-old man was referred for HTG management. His reported TG levels ranged between 490 and 559 mg/dL without any other adverse lipid levels for several years without a history of pancreatitis or diabetes mellitus. Intriguingly, he reported a family history of HTG.

Since TG-lowering medications (fibrates and fish oil) had not reduced his TG levels, specialized lipid analyses were obtained: a non-blanked TG level of 521 mg/dL and a glycerol-blanked TG of 66 mg/dL, consistent with pseudo-HTG or hyperglycerolemia. Repeat glycerol blanked TG levels were 68 and 69 mg/dL, confirming the previous result, and the likely diagnosis of GKD.

With two methods, estimated TG levels were calculated, using some of his laboratory values: (1) modified Friedewald equation to solve for TG with a direct LDL (dLDL) value, and (2) the application of a newly developed formula derived from a collection of 17,545 patient samples, to calculate the absolute TG-gap, using apolipoprotein A and B, estimating TG levels (% deltaTG), and determining whether a TG mesurement might be falsely deviated from the “plausible” TG value.

Although neither methods showed perfect concordance, the calculated TG-valued derived by the two methods were significantly lower than the non-glycerol blanked TG values. The difference was statistically significant (p<0.05).

Conclusion: The patient was clinically diagnosed with GKD, and was taken off of fibrate and the recently added niacin. These two methods can be used quickly to screen for pseudo-HTG or patients with GKD. Currently, it is unknown whether high glycerol levels are associated with high cardiovascular risks.

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<![CDATA[SAT-551 Sparing Confirmatory Tests in Primary Aldosteronism]]> https://www.researchpad.co/article/elastic_article_6935 Context: The current clinical guidelines suggest that confirmatory tests for primary aldosteronism (PA) may be excluded in some of patients who have elevated plasma aldosterone concentration (PAC) under plasma renin suppression. However, this has low priority evidence and is under debate in use of serum potassium. Objective: This study aimed to investigate an appropriate setting for sparing confirmatory tests in PA. Design and Setting: A retrospective cross-sectional study in a single referral center. Participants: This study included 327 patients who had hypertension under plasma renin suppression and underwent captopril challenge test (CCT) between January 2007 and April 2019. CCT results were used to diagnose PA. Main outcome measure: Diagnostic value of PAC and serum potassium in confirmation of PA. Results: Of the studied patients, 252 of 327 (77%) were diagnosed with PA. All 61 patients with PAC >30 ng/dl were diagnosed with PA. In patients with PAC between 20 and 30 ng/dl, 44 of 55 (80%) were diagnosed with PA, while all 26 with PAC between 20 to 30 ng/dl who had spontaneous hypokalemia were diagnosed with PA. Areceiver operator curve analysis showed that the sensitivity of diagnosis of PA is 100% in our patients, when PAC set at > 28.8 ng/dl and showed that the sensitivity of diagnosis of PA is 100% in our patients with spontaneous hypokalemia, who had PAC < 30 ng/dl, when PAC was set at > 19.2 ng/dl. While, the prevalence of PA was higher in patients with hypokalemia, who had PAC between 10 and 20 ng/dl than in those with PAC < 10 ng/dl. Collectively, 100 out of 102 (98%) with hypokalemia, who had PAC > 10 ng/dl were diagnosed as PA. The proportion of unilateral PA determined by adrenal vein sampling (AVS) was higher in patients who had PAC >30 ng/dl or those with spontaneous hypokalemia who had PAC between 20 and 30 ng/dl than those who did not meet the criteria (76% vs. 17%, P<0.001). Conclusion: Confirmatory tests in PA could be spared in patients who have typical features of PA and these patients had a high probability of unilateral PA on AVS.

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<![CDATA[SAT-574 Whole Exome Sequencing Identifies Several Variants Associated with Immune Deficiency, Inflammasomopathy and Non-Ischemic Dilated Cardiomyopathy in a Complex Case of Acquired Generalized Lipodystrophy]]> https://www.researchpad.co/article/elastic_article_6931 Background: Acquired generalized lipodystrophy (AGL) is characterized by near-total fat loss that develops after birth. Although the molecular pathogenesis of AGL is unclear, there is a link to autoimmunity and inflammation. Notably, the panniculitis associated variety of AGL may present with subcutaneous inflammatory nodules that ultimately progress to generalized fat loss. Here, we report on a complex patient with AGL in whom whole-exome sequencing (WES) identified several pathogenic variants and variants of uncertain significance (VUS) that encourage us to think about AGL more broadly. Clinical Case: This is a 38-year-old male who was first diagnosed with juvenile rheumatoid arthritis at age 2, after being evaluated for delayed ability to ambulate. At that time, he was also diagnosed with Weber-Christian disease following a skin biopsy due to the suspicion of panniculitis. Over time, he progressively lost body fat throughout the body and developed hypertriglyceridemia, hypertension, and nephropathy leading to the diagnosis of AGL. At age 10, he was diagnosed with type 1 diabetes mellitus, and at age 14, with autoimmune hepatitis. Due to the tightening of his hands, calf pain, and increased CPK levels, a muscle biopsy was performed, suggesting polymyositis. He had been treated with azathioprine and steroids, which were discontinued at age 26, after a liver biopsy that showed grade 2 fibrosis. Further, he was diagnosed with non-ischemic dilated cardiomyopathy (DCM), evolving with atrial fibrillation with a rapid ventricular response and complicated with left atrial appendage thrombus. Of interest, his mother and two maternal aunts had been diagnosed with atrial fibrillation. One of his maternal uncles presented non-ischemic cardiomyopathy and an early sudden cardiac arrest. His mother also had mitochondrial myopathy, and his father had type 2 diabetes mellitus and IgG deficiency. WES identified three different variants: a maternally inherited pathogenic variant in TTN (c.88473_88477delAGCTT; p.W29493X) associated with DCM, a paternally inherited pathogenic variant in TNFRSF13B (c.310T>C; p.C104R) associated with CVID/IgA deficiency, and a maternally inherited variant of uncertain clinical significance in NLRP3 (c.1469G>A; p.R490K). Although the frequency of this variant was relatively high, several variants in the NLRP3 gene have been previously associated with inflammasomopathy. Conclusion: This case highlights challenging presentations of AGL and the complexity of the disease. As we are yet beginning to understand the molecular mechanisms behind the so-called “acquired fat loss” and its relation to inflammatory and complex immune system diseases, further efforts are critical to better recognize different AGL phenotypes and phenotype-genotype correlations. Additional efforts should be placed on WES for AGL patients and functional validation of identified VUSs.

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<![CDATA[SUN-542 The Effect of Energy Deprivation on Metabolic Hormone Responses to Meals]]> https://www.researchpad.co/article/elastic_article_6797 Background: Intermittent caloric restriction (ICR) has recently gained popularity as a weight-loss strategy; however, fasting metabolic hormones and dynamic meal-related responses, are not well-established in this setting. Methods: We measured metabolic hormone responses to 5-days of neutral or decreased energy availability (NEA, 45 kcal/kg LBM*d vs DEA, 20 kcal/kg LBM*d) in the early follicular phase (EFP) in 19 regularly-cycling, sedentary, women (age 23.36± 2.08 yr; mean±SD). Hunger was assessed using a visual analogue scale on the 5th day of each condition. Scheduled breakfast and lunch were administered according to assigned caloric intake, while an afternoon snack based on NEA was provided on both occasions. Blood was sampled for leptin, insulin, glucose, and GH at 10-min intervals and cortisol was measured at 30-min intervals over eight hours starting at 0800 h, while Orexin A and adiponectin were measured in fasting samples. AUC for each hormone for every meal and diet condition were analyzed using linear mixed models. Insulin and insulin/glucose ratio (I/G) were also adjusted for meal calories. Percentage body fat mass was measured every visit using air displacement plethysmography (BodPod®). Results are presented as least square mean ± sem. Results: There were no differences in body mass index or % fat mass after NEA vs DEA although there was a significant increase in hunger with DEA (p=0.002). Fasting levels of glucose and insulin were unchanged while leptin decreased with DEA (1.27±0.07 and 1.04±0.07 ng/mL, NEA and DEA respectively; p<0.0001), and Orexin A increased (0.55±0.04 and 0.60±0.04 ng/mL; p=0.04). The AUC for glucose was lower with DEA across all meals (p<0.0001). Insulin, I/G and I/G normalized for ingested calories (nI/G) decreased in response to DEA (p<0.005, p<0.05 and p<0.0001). The slope of the increase in leptin across the day was not different between NEA and DEA (p=0.20). Adiponectin, GH and cortisol were unaffected by DEA. Conclusion: These studies indicate that although fasting glucose and insulin are unaffected by short-term caloric restriction, the insulin response to glucose is attenuated even when adjusting for meal-related calories. Orexin A increased and leptin decreased with reduced caloric intake, acting, at least in part, to stimulate appetite. Taken together, these hormonal responses, directed at preserving energy homeostasis, have important implications for understanding the potential efficacy of intermittent caloric restriction.

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<![CDATA[SUN-565 The Effect of Leptin Treatment on Blood Pressure and Autonomic Nervous System Function in Patients with Lipodystrophy]]> https://www.researchpad.co/article/elastic_article_6766 Leptin is an adipokine that reflects energy storage levels. Patients with obesity have high leptin, hypertension, and increased cardiovascular disease (CVD) risk. In rodents, leptin increases blood pressure (BP), by increasing sympathetic nervous system (SNS) activity, suggesting high leptin may cause hypertension and CVD. Studies of leptin administration in 2 human models of leptin deficiency (weight reduced and congenital leptin deficiency) showed decreased SNS activity in the leptin-deficient state, which increased after leptin replacement. This has clinical relevance as high SNS and low parasympathetic nervous system (PNS) activity correlate with increased risk of hypertension and CVD. In lipodystrophy syndromes adipose tissue is deficient thus leptin is low. We hypothesized that leptin treatment in patients with lipodystrophy would increase SNS activity and BP. SNS and PNS activity in the heart can be assessed using heart rate variability (HRV). The high frequency (HF) component of HRV is directly related to PNS activity whereas the low frequency (LF) component reflects both SNS and PNS. The LF/HF ratio reflects sympathetic-vagal balance. Lower standard deviation of the beat to beat interval (SDNN) inversely correlates with CVD risk. Leptin-naïve patients with lipodystrophy (N=17, 5 generalized, 12 partial) were housed on an inpatient unit for 19 days. Patients were studied without leptin for the first five days. Leptin was administered for the next 14 days. At the end of the OFF-leptin and ON-leptin periods, 24-hr EKG recordings were used to derive HRV parameters and an automated BP monitor measured BP every 30 minutes during the day and every 60 minutes at night. 5 patients had generalized lipodystrophy (median 25th,75th percentile] endogenous leptin [0.5 [0.4, 0.6] ng/mL); 12 had partial lipodystrophy (leptin 7.5 [3.9, 20.3]). In the combined cohort with generalized and partial lipodystrophy, leptin treatment did not alter BP or any measure of autonomic nervous system function after 24 hours, 2 weeks, or 6 months. In exploratory subgroup analyses of generalized vs partial lipodystrophy, those with generalized lipodystrophy had an increase in LF after 2 weeks of leptin and a 4.5 mm Hg increase in systolic BP after 6 months; no changes were observed in those with partial lipodystrophy. Unlike previous human and rodent studies, we did not see increased SNS tone or BP after leptin treatment in patients with lipodystrophy. However, exploratory analyses in patients with generalized lipodystrophy and very low endogenous leptin levels showed small increases in systolic BP and increased LF component of HRV after 2 weeks, which is regulated by both SNS and PNS. This suggests that leptin may alter autonomic function in the transition from very low to normal plasma leptin levels.

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<![CDATA[SUN-543 Real World Evidence of Successful Weight Management for the Obese Population: Complete Reversal of Obesity Related Metabolic Co-Morbidities and Weight Loss in Patients Attending a Multidisciplinary Weight Management Clinic in Australia]]> https://www.researchpad.co/article/elastic_article_6724 Over 2.5 billion people worldwide are overweight or obese. Multidisciplinary weight management interventions have evolved to address the complexity of weight loss for those with one or more chronic diseases, and the trend of weight regain. The aim of these interventions is to encourage sustainable lifestyle changes, resulting in weight loss and weight maintenance and improvements in comorbidities. While some prospective clinical trials have demonstrated efficacy, results are often not reported by real life practices.

The aim of this study was to evaluate the effectiveness of a Sydney based multidisciplinary weight management clinic with endocrinology, dietetics, exercise physiology, psychology, and bariatric surgical domains. All patients who attended the clinic for weight loss purposes between March 2017 and April 2019 were included (n=220). A retrospective chart review was conducted. Patient data on weight, BMI, waist circumference, body composition measurements, and selected blood test results and co-morbidities were analysed. All patient therapy included endocrinological input for co-morbidity identification and management, lifestyle intervention (dietetic and exercise physiology input) with optional adjunct pharmacotherapy or psychological counselling. Of the 220 cohort, 20 of the patients had sleeve gastrectomy.

Patient retention in the clinic after the first consultation was 85% (n=186), a high rate within the weight management community. 59% of patients achieved a minimum of 5% total body weight loss, including 18% who achieved greater than 10% total body weight loss. Additionally, 31% of patients lost enough weight to decrease their BMI class by up to 2 or more classes. Of the gastric sleeve cohort average excess body weight loss was 32kg (21-56kg) enhanced by multidisciplinary care in the lead up to surgery. Across the cohort some patients completely reversed co-morbidities; including dyslipidaemia (n=1), hypertension (n=3), NAFLD (n=1), pre-diabetes (n=8) and type 2 diabetes (n=3), OSA (n=1). These results demonstrate that obesity is a chronic condition that can be successfully managed. We have demonstrated significant durable weight loss and improvement in metabolic co-morbidities with holistic coordinated care. Future directions include translating this model of care into standard practice in Australia and other countries where obesity to date not received the same coordinated approach as other chronic conditions.

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<![CDATA[OR17-02 Changes in Hepatokines and Apolipoproteins Are Associated with Metabolic Response to Metreleptin in Partial Lipodystrophy]]> https://www.researchpad.co/article/elastic_article_6708 Introduction Metreleptin treatment may improve the metabolic aspects of partial lipodystrophy; however, the treatment response is heterogeneous. This study aimed to explore changes in circulating apolipoprotein concentrations, as well as ANGPLT3, ANGPLT4, and IGF-1 levels in patients treated with Metreleptin as part of a clinical study investigating the efficacy of Metreleptin in nonalcoholic steatohepatitis (NASH) associated with partial lipodystrophy (ClinicalTrials.gov identifier: NCT01679197). Methods Serum samples of 18 patients with partial lipodystrophy who underwent a full metabolic evaluation and paired liver biopsies before and after Metreleptin were studied. Patients were tested at baseline, month (M) 3, M6, and M12. Glycemic response was defined as “more than 1% HbA1c reduction from baseline”. Lipid response was defined as “more than 30% decrease in triglycerides from baseline”. The hepatic response was defined as “a decrease of 2 points or more from baseline in NASH score, without an increase in fibrosis”. Patients with “any 2 of 3 above” at M12 were defined as metabolic responders. Results Metreleptin treatment resulted in significant reductions in triglycerides (346 mg/dL vs. 253 mg/dL; F: 8.474; p < 0.001), apo B (145.24 mg/dL vs. 111.09 mg/dL; F: 9.266: p < 0.001), apo CII (18.65 mg/dL vs. 15.95 mg/dL; F: 6.663: p = 0.001), apo CIII (62.95 mg/dL vs. 49.33 mg/dL; F: 5.640, p = 0.002), apo E (8.16 mg/dL vs. 6.52 mg/dL; F: 11.056, p < 0.001), and ANGPLT3 (14.36 ng/mL vs. 12.00 mg/dL; F: 4.348; p = 0.008) over time. IGF-1 levels significantly increased at M3 (134 ng/mL vs. 139 ng/mL; p = 0.001), however the difference was not significant over time. Metabolic responders had lower baseline leptin (12.4 ng/mL vs. 27.8 ng/mL; p = 0.024) and IGF-1 (95 ng/ml vs. 151 ng/mL; p = 0.008), and higher apo CII (39.06 mg/dL vs. 17.90 mg/dL; p = 0.011), apo CIII (173.57 mg/dL vs. 51.51 mg/dL; p = 0.015), apo E (18.41 mg/dL vs. 5.89 mg/dL; p = 0.002), and ANGPLT3 (17.33 ng/mL vs. 10.06 ng/mL; p = 0.04). Metabolic responders had a significant increase in IGF-1 (95 ng/mL vs. 134 ng/mL; p = 0.019), which was statistically distinguished from non-responders (p = 0.004). Responders also had a greater reduction in apo CII (20.51 mg/dL vs. -1.84 mg/dL; p = 0.001), apo CIII (32.59 mg/dL vs. -7.83 mg/dL; p = 0.007), apo E (8.17 mg/dL vs. 0.22 mg/dL; p = 0.001), and ANGPLT3 (6.08 ng/mL vs. -0.16 ng/mL; p = 0.005) early after treatment at M3. Conclusions Metreleptin treatment lowers levels of apolipoproteins associated with triglyceride metabolism as well as ANGPLT3 in patients with partial lipodystrophy. Metabolic response to Metreleptin appears to be correlated with early changes in these factors and an increase in IGF-1 levels.

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<![CDATA[SUN-573 Use of PCSK9 Inhibitors Post-Transplant]]> https://www.researchpad.co/article/elastic_article_6645 Background:

Dyslipidemia is common in patients after transplant. While statins are the mainstay of therapy, interactions with immunosuppressants such as calcineurin inhibitors (CNIs) can limit dose titration or lead to intolerance of this important drug class. Withdrawal of statin therapy can precipitate hyperlipidemia and potentially accelerate cardiovascular disease in transplant recipients, including coronary allograft vasculopathy (CAV) in heart transplant (HT) patients. Proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i) may provide a safe, effective option for such patients. PCSK9i profoundly reduce low-density lipoprotein (LDL) and subsequently the risk of cardiovascular events in nontransplant patients. Further, these novel agents have no known interactions with CNIs. There is a paucity of data describing PSCK9i use post-transplant, with only a few small case series reported in HT recipients. Here, we summarize our experience along with available literature on this topic.

Methods:

In this retrospective case series we investigated adult recipients of heart transplant who were treated with PCSK9 inhibitors from July 2015 to 2019 because of statin intolerance or refractory hyperlipidemia. We compared the data of patients at baseline and after various durations of therapy with the PSCK9i evolocumab and alirocumab using the median and interquartile range (IQR). Specifically, we evaluated PCSK9i efficacy, effect on immunosuppressant levels, cardiac function and adverse events.

Results:

Five patients (4 men; median age 54, IQR 52-60) underwent heart transplant an average of 7.4 years ago. Median treatment duration of evolocumab or alirocumab was 12 months (IQR 7-17). This led to a reduction of total cholesterol by 94 mg/dl (p=0.04) (47% decrease) and LDL cholesterol by 83 mg/dl (p=0.04) (69% decrease). No statistically significant difference in HDL cholesterol, triglycerides or liver function tests (LFTs) were observed. There were no episodes of rejection. Immunosuppressant levels remained at goal. One patient noted a few days of fatigue after alirocumab injections but otherwise no side effects were reported.

Conclusion:

The PCSK9 inhibitors evolocumab and alirocumab are promising alternatives to statin therapy in transplant recipients with statin intolerance or refractory hyperlipidemia. Our study showed their potential to significantly reduce LDL cholesterol in heart transplant patients without altering IST levels. No episodes of transplant rejection were noted. Further long-term studies to establish the safety and efficacy of PSCK9 inhibitors post-transplant are needed.

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<![CDATA[SAT-563 The Unsuppressed Plasma Renin Activity May Not Enough for Management of Non-Surgically Treated Primary Aldosteronism]]> https://www.researchpad.co/article/elastic_article_6635 It is well known the primary aldosteronism (PA) is most common endocrinological hypertension and accounted for 10% among all hypertension population, and it develops cardiovascular disease more frequently than blood pressure matched essential hypertension. Those patients with bilateral hyperaldosteronism, called idiopathic hyperaldosteronism (IHA), or unwilling for surgical treatment are treated by mineralcorticoid receptor antagonists (MRAs). Although it had been unclear how titrate MRAs to prevent atherosclerotic cardiovascular events, a managemental target for those patients was recently reported as plasma renin activity (PRA) ≥ 1.0 ng/ml/hr to prevent cardiovascular events (Hundemer GL, et. al. Lancet Diabetes Endocrinol. 2018 Jan;6(1):51-59).

Thus, we investigated 77 cases of adrenal venous sampling performed patients with PA and followed up for 3 years in our hospital since 2007, including 24 males and 53 females, and their mean age was 56.3 ± 12.5 years old. All patients underwent AVS and showed bilateral hyperaldosteronism and treated with MRAs and followed up more than 3 years. We collected blood pressure, serum sodium and potassium concentration, estimated glomerular filtration ratio (eGFR), PRA, plasma aldosterone concentration (PAC), atherosclerotic parameter, such as mean intima media thickness (IMT), brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI). We evaluated the relationship of those patients’ PRA and aldosterone to renin ratio (ARR) with eGFR, IMT, baPWV, and ABI. The change of mean IMT after 3 year-follow up were 0.03 ± 0.11 mm vs. 0.06 ± 0.09 mm for well controlled (PRA ≥ 1.0 ng/ml/hr) and poorly controlled (PRA < 1.0 ng/ml/hr), respectively, and no significant difference between them. In the other hand, the change of mean IMT after 3 year-follow up showed 0.03 ± 0.10 mm vs. 0.08 ± 0.10 mm for well controlled (PRA ≥ 1.0 ng/ml/hr and ARR <20) and poorly controlled (PRA < 1.0 ng/ml/hr or ARR ≥ 20), respectively, and the mean IMT increase was significantly lower in this group.

The mean IMT increase showed significantly lower only with PRA ≥ 1.0 ng/ml/hr and ARR <20 rather than PRA ≥ 1.0 ng/ml/hr alone.

In our results, both PRA ≥ 1.0 ng/ml/hr and ARR<20 are important to prevent or improve atherosclerosis, rather than only PRA ≥ 1.0 ng/ml/hr and should be titrated MRAs to achieve this target.

In conclusion, our result revealed the titration of MRAs is important to prevent atherosclerotic cardiovascular event and not only PRA ≥ 1.0 ng/ml/hr, but both PRA and ARR <20 should be achieved.

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<![CDATA[SAT-550 Changes in Albuminuria Precede Dietary Sodium-Dependent Changes in BP During Aging - a Longitudinal Study]]> https://www.researchpad.co/article/elastic_article_6574 Background: Hypertension (HT) is a well-established independent risk factor for adverse cardiovascular and renal (CVR) outcomes and a high salt (HS) diet is the main cause for high blood pressure (BP). Despite extensive research focusing on HT, surprisingly there are no longitudinal studies assessing the long-term effects of HS. Aims: This study aimed (1) to evaluate the timing of onset for changes in CVR health during long-term sodium loading and (2) to assess whether salt restriction can prevent these effects.

Methods: C57BL/6 mice were randomized to HS, moderate (NS) or low (LS) salt diet and followed longitudinally for 50 weeks (wks). BP, urinary albumin/creatinine ratio (AC), plasma aldosterone (PA) and renin activity (PRA) were assessed monthly. At the end of the study, renal artery resistance and left ventricular (LV) parameters were measured by ultrasound and echocardiogram. Renal AT1 expression (Western Blot) and activity (IHQ) were quantified.

Results: At the beginning of the study, there were no differences in BP and AC between the three dietary groups. Relative to wk 1, BP (mmHg) in the HS group was higher in wk 21 (131±1.7 vs. 115±3.0, p= 0.05). Sodium restriction delayed this increase: SBP was higher in wk 41 in the NS group compared to the wk 1 (128±3.4 vs. 115±6.4, p= 0.05) but did not reach significance in the LS group until the end of the study. Similarly, relative to wk 1, AC (µg/mg) only in the HS group reached significantly higher levels in wk 17 (44±4.2, p<0.05). Again, sodium restriction delayed the occurrence of renal damage. AC reached significance in wks 25 and 41 for NS and LS (35±1.1 and 42±2.6 respectively, p<0.05 vs. baseline). Interestingly, the changes in AC always preceded the changes in BP, irrespective of diet. PA and PRA were appropriately activated by dietary salt restriction and suppressed by aging. The aging-induced suppression appeared stronger for PA than for PRA in the HS group only. Long-term sodium loading (HS) induced increased renal resistance, which was prevented in the LS but not in the NS group. Relative to HS, the LV mass index and cardiac output were lower in the NS and LS groups (p<0.05). LV volume indices and ejection fraction did not differ between groups. Renal AT1 protein expression and activation status (IHQ) were decreased in the sodium restricted group. Conclusions: Our study showed that long-term exposure to HS induced a progressive increase in BP and AC in mice. Importantly, these changes were delayed by long-term reduction in sodium intake. Interestingly, changes in AC preceded those in BP, irrespective of diet. Cardiac parameters suggest a sodium-induced eccentric cardiac hypertrophy in the older age, which was prevented by sodium restriction. One possible mechanism behind these effects is the overactivation of the AT1 receptor pathway.

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