Sex-Specific Associations of Aldosterone and Renin with Body Composition: A Population-Based Cohort Study.

CONTEXT: Renin-angiotensin-aldosterone system (RAAS) activation is closely linked to obesity; however, the sex-specific associations between RAAS activity and body composition among individuals without obesity are not well understood. OBJECTIVE: To investigate the associations of aldosterone and renin with body composition according to sex in the general population. DESIGN: Population-based cohort study. SETTING: Québec (Canada). PARTICIPANTS: Adults aged 40-69 years enrolled to CARTaGENE between 2009 and 2010 (N=3,687). EXPOSURES: Plasma aldosterone and renin concentrations. MAIN OUTCOME MEASURES: Body composition assessed via anthropometrics (waist circumference and waist-to-hip ratio), bioelectrical impedance (lean body mass, fat mass, and muscle mass), and cardiac magnetic resonance imaging (epicardial and pericardial adipose tissue volumes). RESULTS: The mean (SD) age and body mass index were 55 (8) years and 27.3 (4.8) kg/m2, respectively. Among males, higher aldosterone and renin were associated with increased waist circumference, increased waist-to-hip ratio, increased fat mass, decreased lean body mass, and decreased muscle mass (p<0.05). Aldosterone (p=0.02), but not renin (p=0.43), was associated with increased ectopic cardiac adiposity in males. In contrast, higher renin (p<0.05), but not aldosterone (p≥0.05), was associated with increased waist circumference, increased waist-to-hip ratio, and increased cardiac adiposity in females. Among females, higher renin and aldosterone were associated with increased fat mass (p<0.05) but were not associated with lean body mass or muscle mass (p≥0.05). All aforementioned associations were independent of body weight. CONCLUSIONS: Independent of body weight, increased RAAS activity is associated with unfavorable differences in body composition; however, the strength and pattern of association varies by sex.

Subtype Identification of Surgically Curable Primary Aldosteronism During Treatment With Mineralocorticoid Receptor Blockade.

BACKGROUND: Current guidelines and consensus documents recommend withdrawal of mineralocorticoid receptor antagonists (MRAs) before primary aldosteronism (PA) subtyping by adrenal vein sampling (AVS), but this practice can cause severe hypokalemia and uncontrolled high blood pressure. Our aim was to investigate if unilateral PA can be identified by AVS during MRA treatment. METHODS: We compared the rate of unilateral PA identification between patients with and without MRA treatment in large data sets of patients submitted to AVS while off renin-angiotensin system blockers and ß-blockers. In sensitivity analyses, the between-group differences of lateralization index values after propensity score matching and the rate of unilateral PA identification in subgroups with undetectable (≤2 mUI/L), suppressed (<8.2 mUI/L), and unsuppressed (≥8.2 mUI/L) direct renin concentration levels were also evaluated. RESULTS: Plasma aldosterone concentration, direct renin concentration, and blood pressure values were similar in non-MRA-treated (n=779) and MRA-treated (n=61) patients with PA, but the latter required more antihypertensive agents (P=0.001) and showed a higher rate of adrenal nodules (82% versus 67%; P=0.022) and adrenalectomy (72% versus 54%; P=0.01). However, they exhibited no significant differences in commonly used AVS indices and the area under the receiving operating characteristic curve of lateralization index, both under unstimulated conditions and postcosyntropin. Several sensitivity analyses confirmed these results in propensity score matching adjusted models and in patients with undetectable, or suppressed or unsuppressed renin levels. CONCLUSIONS: At doses that controlled blood pressure and potassium levels, MRAs did not preclude the identification of unilateral PA at AVS. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01234220.

A 52-Year-Old Woman with Weakness and Confusion.

A 52-Year-Old Woman with Weakness and ConfusionA 52-year-old woman presented for evaluation of abdominal pain, weakness, and confusion. How do you approach the evaluation, and what is the diagnosis?

Resolution of PTHrP-Mediated Hypercalcemia Following Treatment with Dual BRAF/MEK Inhibition for BRAFV600E-Positive Metastatic Ameloblastoma.

Ameloblastoma is a rare odontogenic tumor which may be complicated by hypercalcemia in advanced disease. Tumoral parathyroid hormone-related peptide (PTHrP) production and local osteolysis from paracrine factors have been proposed as mechanisms. Mitogen-activated protein kinase (MAPK) inhibitors have been successfully used in ameloblastomas with BRAF V600E mutation to reduce symptoms and decrease tumor burden. Serum calcium has been observed to normalize following treatment with MAPK inhibitors; however, the response of PTHrP and markers of bone turnover has not been reported. We describe a case of a 55-year-old female with PTHrP-mediated hypercalcemia secondary to BRAF V600E-positive ameloblastoma with pulmonary metastases. Following treatment with dabrafenib and trametinib, the patient experienced the regression of pulmonary lesions and normalization of serum calcium, PTHrP, and markers of bone turnover. Tissue samples of ameloblastoma carrying BRAF V600E mutation are more likely to express PTHrP than tissue samples carrying wild-type BRAF. In our case, resolution of PTHrP-mediated hypercalcemia following initiation of BRAF/MEK inhibition provides additional evidence that the MAPK pathway contributes to PTHrP synthesis. It also raises the question of whether MAPK inhibitors would be effective in treating PTHrP-mediated hypercalcemia associated with other malignancies harboring BRAF V600E mutation.