Increased aldosterone/renin ratio in obese hypertensive women

Obesity is strongly associated with arterial hypertension. Several pathophysiological mechanisms have been proposed to explain the obesity-related hypertension, but the exact mechanism involved remains unclear. We have recently observed that mineralocorticoid-stimulating factors secreted by human fat cells stimulate aldosterone secretion from adrenocortical cells, thus suggesting that a hyperaldosteronism may be a direct link between obesity and arterial hypertension. Based on these findings we evaluated components of the renin-angiotensin-aldosterone system in obese patients and their correlation with arterial hypertension.

Material and Methods: Nineteen normotensive and eighteen hypertensive women underwent measurements of blood pressure, height, weight, glucose tolerance and plasma levels of aldosterone, renin and electrolytes. The patients studied were all obese (BMI ≥ 30kg/m²), non-diabetics and under no hypertensive medication.

Results: The group of hypertensive obese women showed significantly reduced plasma levels of renin (p<0,05) as well as an increased aldosterone/renin ratio (p<0,005) in comparison to the obese normotensive women. Plasma aldosterone levels were not significantly different between both groups. No difference was observed in the glucose tolerance test and plasma levels of potassium and sodium between obese hypertensive and normotensive women. In conclusion, these data reinforce the hypothesis that an abnormal aldosterone secretion is involved in the obesity-related arterial hypertension.