Visceral obesity and insulin resistance are associated with plasma aldosterone levels in women

Objective: Both obesity and insulin resistance increase the risk of hyperte nsion and other cardiovascular diseases, but the mechanisms linking these a bnormalities are unknown. The current study was undertaken to examine the e ffects of obesity, fat, distribution, and insulin resistance on plasma leve ls of aldosterone and other adrenal steroids that might contribute to seque lae of obesity. Research Methods and Procedures: Twenty-eight normotensive premenopausal women and 2 7 normotensive men with a wide range of body fat underwent measurements of visceral adipose tissue by CT scan, total fat mass by dual energy X-ray abs orptiometry, blood pressure, insulin sensitivity, and plasma levels of thre e adrenal steroid hormones. Results: Plasma aldosterone in women correlated directly with visceral adip ose tissue (r = 0.66, p < 0.001) and inversely with insulin sensitivity (r = -0.67, p < 0.001), and these associations were independent of plasma reni n activity. There were no corresponding correlations in men. Plasma aldoste rone was significantly correlated with plasma cortisol and dehydroepiandros terone sulfate in women. Seventeen women and 15 men completed a weight-redu ction regimen, losing an average of 15.1 +/- 1.2 kg. After weight loss, pla sma aldosterone was significantly lower and insulin sensitivity higher; how ever, the correlations of aldosterone with visceral adipose tissue and insu lin sensitivity in women persisted (p = 0.09 and 0.07, respectively). Altho ugh none of the women were hypertensive, blood pressure correlated with pla sma aldosterone both before and after weight loss. Discussion: We conclude that visceral adiposity and insulin resistance are associated with increased plasma aldosterone and other adrenal steroids tha t may contribute to cardiovascular diseases in obese women.