Obesity hypertension: The effects on cardiovascular and renal systems

Obesity has deleterious effects on overall health, especially on the heart and the kidney. Hypertension occurs more commonly in obese than in lean persons at virtually every age. A variety of endocrine, genetic, and metabolic mechanisms have been linked to the development of obesity hypertension. These include insulin resistance and hyperinsulinemia, increased serum aldosterone levels, salt sensitivity, and expanded volume with inappropriately increased peripheral vascular resistance, a genetic predisposition, and possible increased leptin levels. Pressure and volume overload are present in obese hypertensives. This leads to a mixed eccentric-concentric form of left ventricular hypertrophy and increases the predisposition to congestive heart failure. Obesity hypertension is associated with a shift of pressure natriuresis toward a higher blood pressure. Renal blood flow is increased, leading to hyperfiltration and eventually to glomerulosclerosis. Weight loss, even in modest decrements, is effective in reducing obesity hypertension, possibly by ameliorating several of the proposed pathophysiologic mechanisms. When weight loss is not possible, pharmacologic therapy may be instituted; angiotensin-converting enzyme inhibitors or angiotensin receptor blockers should be the first-line drugs. Low-dose diuretics should be added as needed.