Obesity and hypertension: cardiovascular response of weight reduction.
There is a close epidemiological association between obesity and blood pressure for all age groups, although not every obese individual becomes hypertensive. In populations without age-related increases in body weight, an elevation of blood pressure with age is not seen. Treatment of obesity by weight loss decreases blood pressure substantially; however, in a minority of patients blood pressure does not fall with weight loss. Blood pressure generally decreases before normal weight is achieved. Blood pressure after weight loss remains reduced as long as there is no marked regain of body weight. Salt intake reduction does not appear to explain why weight reduction lowers blood pressure. Reduced levels of plasma renin activity, serum aldosterone levels, catecholamine levels, and serum insulin levels may be involved in the blood pressure lowering associated with weight loss. Since the risk to the hypertensive patient is not only determined by the blood pressure, an overall treatment that aims at reduction of all risk factors is advocated. Some risk factors, e.g., glucose intolerance, may be normalized only when desirable weight is achieved. Thus, in any obese hypertensive patient with other risk factors, normalization of excess body weight appears to be the first the most important step of any rational therapeutic strategy.