The relationship between obesity-related metabolic factors and vascular changes in early hypertension

The relationships of obesity, glucose metabolism and hormonal variables to mean arterial pressure (MAP) regional vascular resistance and signs of structural vascular changes, were determined in 70 men aged 49 years with normal to mildly elevated MAP randomly selected from a population sample. Regional vascular resistances and signs of structural vascular changes were measured in the calf by plethysmography at rest and during maximal dilatation, and in the kidneys by renal blood flow determination during graded subpressor doses of angiotensin II. MAP was positively correlated to body fat, waist circumference, fat cell size, and to blood glucose 60 minutes after an oral load. This supports an association between central obesity, impairment of glucose tolerance and hypertension. MAP was, however, unrelated to sodium intake, blood volume and indices of sympathetic nervous activity and the renin-angiotensin system. Resting vascular resistance in the calf was unrelated to MAP, while renal vascular resistance rose significantly with increasing MAP. Signs of structural change were significantly correlated to MAP in both these vascular areas. These signs were also associated with central obesity of the hypertrophic type and with impairment of glucose tolerance, even when the association to MAP was accounted for. These factors may be involved in the pathogenesis of the structural adaptation of resistance vessels as hypertension develops.