Endocrine Abstracts

Background: Incidentally discovered adrenal adenomas (AA) are associated with increased prevalence of hypertension, obesity, and impaired glucose tolerance, all established risk factors for cardiovascular (CV) morbidity. However, most studies were performed in patients with AA and autonomous cortsisol and/or aldosterone secretion, whereas the presence of cardiovascular risk in patients with non-secreting AA has not been looked into detail.

Methods: Cardiovascular risk factors were studied in 18 patients with non-secreting unilateral adrenal adenoma (AA) (52.5±2.1 years, BMI 27.8±0.8 kg/m²) (mean±s.e.m.) and in 22 healthy age and BMI matched subjects that served as control group (C) (51.5±1.5 years, BMI 26.8±0.9 kg/m²). Patients with AA had complete inhibition of serum cortisol and aldosterone levels after a low dose DXM suppression test and intravenous NaCl 0.9% infusion test, respectively. Fasting measurement of serum triglycerides, total cholesterol, high and low density lipoproteins, fibrinogen, homocysteine, Lipoprotein(a) (Lp(a)), Apolipoprotein B (apo-B), Apolipoprotein A-I (apo-A) was performed. All patients also underwent a 2 h oral glucose tolerance test (OGTT) and insulin sensitivity was assessed by calculating HOMA((fasting glucose (mmol/l)*fasting insulin(μIU/ml))/22.5) and Matsuda {10 000/square root((fasting glucosexfasting insulin)*(mean OGTT glucose*mean OGTT insulin)} indices. Carotid artery intima-media-thickness (IMT) and brachial artery flow-mediated dilation (FMD) were measured using high resolution linear array ultrasound.

Results: Patients with AA had increased homocysteine (13.3±0.6 vs 10.3±0.4 mg/dl, P<0.01), Lp(A) (21.2±7 vs 5.6±0.4 mg/dl, P<0.05), fibrinogen (391.7±20.4 vs 310.3±21.7 mg/dl, P<0.05) and apo-B/apo-A ratio (0.76±0.04 vs 0.55±0.03, P<0.01) compared to C. Patients with AA had higher IMT values than C (0.93±0.05 mm vs 0.78±0.02, P=0.018) and lower FMD levels (3.6±0.3 vs 5.9±0.4, P<0,01). Compared to C HOMA and Matsuda index were significantly higher (2.67±0.19 vs 1.72±0.14 mmol/mU per l, P<0.01) and lower (3.5±0.3 vs 6.6±0.4, P<0.01) in AA.

Conclusion: Patients with non secreting AA exhibit increased CV risk factors. Studies examining cardiovascular morbidity and mortality in such patients are further required.