New developments in mechanisms of obesity-induced hypertension: role of adipose tissue.

Hypertension develops in almost 60% of obese individuals. Apart from the recent observation of obesity-associated structural changes in kidney structure that may lead to enhanced tubular sodium reabsorbtion, reports of paracrine and hormonal factors derived from adipose tissue have prompted speculations about the role of adipose tissue in the pathophysiology of obesity-induced hypertension. We summarize recent data on leptin's sympathoexcitatory actions, the possible influence of adipose tissue on atrial natriuretic peptide levels, and the formation of vasoactive substances, such as angiotensin II and nonesterified fatty acids, by adipocytes. The mechanisms discussed herein may contribute to the typical findings in obesity-induced hypertension, including volume expansion, sodium retention, enhanced sympathetic nervous system activity, increased activity of the systemic renin-angiotensin system, low atrial natriuretic peptide levels, and disturbed glucose and insulin metabolism. Together, these data strengthen the hypothesis that adipose tissue is potentially a major regulator of cardiovascular-renal function.