Obesity-hypertension: emerging concepts in pathophysiology and treatment.

The incidence and prevalence of obesity has risen markedly in the last decade, and this epidemic represents a serious health hazard with significant morbidity and mortality. Although hypertension is recognized as one of the most serious consequences of obesity, its pathophysiology remains incompletely understood. Contemporary research suggests that the recently discovered hormone leptin may represent a common link between these 2 pathologic conditions. Leptin is primarily synthesized and secreted by adipocytes. One of the major functions of this hormone is the control of energy balance. By binding to receptors in the hypothalamus, it reduces food intake and promotes elevation in temperature and energy expenditure. In addition, increasing evidence suggests that leptin, through both direct and indirect actions, may play an important role in cardiovascular and renal functions. Although the relevance of endogenous leptin needs further clarification for the control of renal sodium excretion and vascular tone, it appears to be a potential pressure and volume-regulating factor in normal situations. However, in conditions of chronic hyperleptinemia, such as obesity, leptin may function pathophysiologically for the development of hypertension as well as cardiac and renal disease. Thus, in addition to weight control, reduction of circulating leptin may confer cardiovascular and renal protective effects in patients with obesity-hypertension.