BODY WEIGHT
Body weight has long been linked to blood pressure levels. More recent findings indicate that the distribution of body fat may be a more important determinant of blood pressure elevation and the risk for cardiovascular disease. An increase in visceral abdominal fat (the central or "apple" form) in contrast to the lower body adiposity pattern (the "pear" shape is linked not only to blood pressure elevation but also to insulin resistance, dyslipidemia and an increased risk for cardiovascular events. These associations have been based largely on epidemiological evidence. However, there are now several intervention trials in which it has been demonstrated that weight loss, often as little as 5 kg rather than a reduction to "ideal" body weight, is associated with a decrease in blood pressure and an improvement in insulin sensitivity.
Studies on both humans and experimental animals suggest that the sympathetic nervous system is involved in the pathophysiology of the weight-blood pressure-insulin resistance relationship, but therapeutic interventions based on these findings are not yet available to confirm this connection.
Another mediator of the body weight-blood pressure relationship appears to be the kidney.
In experimental animals, obesity has been associated with alteratiQlls in renal blood flow and glomerular filtration rate or intraglomerular pressure. In humans, urinary micro albumin excretion was increased among obese subjects, supporting an abnormality in renal function m humans as well. Moreover, micro albuminuria has been linked to an increased risk of diovascular events in hypertensive individuals.
