Pathophysiology and treatment of obesity hypertension.

Excess weight gain accounts for as much as 65-75% of the risk for essential hypertension and also greatly increases the risk for end stage renal disease (ESRD). Obesity raises blood pressure by increasing renal tubular reabsorption, impairing pressure natriuresis, and causing volume expansion due to activation of the sympathetic nervous system (SNS) and renin-angiotensin aldosterone system (RAAS), and by physical compression of the kidneys, especially when visceral obesity is present. The mechanisms of SNS activation in obesity are still unclear but may be due, in part, to hyperleptinemia that stimulates the hypothalamic pro-opiomelanocortin (POMC) pathway. With prolonged obesity, there may be a gradual loss of kidney function that worsens with time, exacerbates hypertension, and makes blood pressure more difficult to control. Lifestyle modifications, including weight reduction and increased physical activity, are essential first steps in the management of obesity hypertension and renal disease. Anti-obesity drugs offer potential pharmacotherapy for obesity hypertension, but current drugs are very limited and additional long-term studies are needed to test their safety and efficacy. Clinical trials are also needed to determine the most effective antihypertensive drugs for obese hypertensive patients. Special considerations for the obese patient, in addition to adequately controlling the blood pressure, include correcting the metabolic abnormalities and protecting the kidneys from further injury.