Overweight and hypertension - A 2-way street?

Cross-sectionally, higher weight is associated with higher blood pressure l evels; prospectively, baseline weight and weight gain predict higher blood pressure. The loss of weight is frequently associated with a decrease in bl ood pressure. These findings suggest that weight gain may pathophysiologica lly contribute to blood pressure elevation. In this review, we present data to indicate that the reverse is also true; persons of equal weight who had higher initial blood pressures gain more weight in the future. We also pro pose a plausible hypothesis to explain this reverse relationship. Both the blood pressure elevation and the gain of weight may reflect a primary incre ase in sympathetic tone. It is well known that in a milieu of increased sym pathetic tone, the beta-adrenergic responsiveness decreases. Sympathetic ov eractivity and decreased cardiovascular beta-adrenergic responsiveness have been described in hypertension. beta-Adrenergic receptors mediate increase s in energy expenditure. If these metabolic receptors were downregulated in hypertension, the ability of hypertensive patients to dissipate calories w ould decrease and they would gain more weight. The possible relationship of decreased beta-adrenergic responsiveness to weight in hypertension can be experimentally tested. Such research may contribute to an explanation of wh y patients with hypertension can rarely lose weight. An understanding of th is pathophysiological relationship may open new avenues for therapeutic int erventions.