Plasma renin levels are associated with cardiac function in primary adrenal insufficiency

BACKGROUND: Despite adequate glucocorticoid (GC) and mineralocorticoid (MC) replacement therapy, primary adrenal insufficiency (AI) is associated with an increased mortality, mainly due to cardiovascular disease. The role of MC replacement is not known. Therefore, we assessed whether renin concentrations during routine GC and MC substitution therapy are associated with heart function and morphology. METHODS: Thirty two patients with primary AI were included in a cross-sectional case–control study. In total, 17 patients and 34 healthy controls (age: 48 ± 12 vs. 46 ± 18 years; BMI: 23 ± 3 vs. 24 ± 3 kg/m(2)) underwent magnetic resonance spectroscopy and imaging measurements to assess cardiac function, morphology, ectopic lipids, and visceral/subcutaneous fat mass. Patients were divided according to their actual plasma renin concentration at the study visit (Actual-Renin(low) vs. Actual-Renin(high)) and their median plasma renin concentration of previous visits (Median-Renin(low) vs. Median-Renin(high)). RESULTS: Ejection fraction was higher (67 ± 5 vs. 55 ± 3%; p = 0.001) and left ventricular mass was lower (60 ± 9 vs. 73 ± 10 g/m(2); p = 0.025) in Actual-Renin(high). Median-Renin(high) was associated with lower cardiac mass (64 ± 9 vs. 76 ± 11 g/m(2); p = 0.029). Blood pressure, glucose, and lipid metabolism, as well as ectopic lipid content, pericardial fat mass, and visceral/subcutaneous fat were not different between the groups. Compared with controls, ejection fraction was significantly lower in patients with AI (56 ± 4 vs. 63 ± 8%; p = 0.019). No differences were found in patients with ≤20 mg compared with >20 mg of hydrocortisone per day. CONCLUSIONS: Higher renin concentrations are associated with more favorable cardiac function and morphology in patients with primary AI.