Close correlation of intra-abdominal fat accumulation to hypertension in obese women. The relation between intra-abdominal visceral fat accumulation and blood pressure was investigated in 67 obese women (mean body mass index, 33.6 +/- 3.1; average age, 50 +/- 11 years). As an index of intra-abdominal fat accumulation, the ratio of the intra-abdominal visceral fat area to subcutaneous fat area was determined using a computed tomographic section at the level of the umbilicus. When the obese subjects were divided into a hypertensive group and a normotensive group, the ratio of the intra-abdominal visceral fat area to subcutaneous fat area in the hypertensive group was significantly higher (0.53 +/- 0.33 versus 0.29 +/- 0.12, p less than 0.01). Significant correlations between the ratio of intra-abdominal visceral fat area to subcutaneous fat area and systolic blood pressure (r = 0.62, p less than 0.001) and diastolic blood pressure (r = 0.53, p less than 0.001) also were found. However, no significant difference existed in either the body mass index or the waist-to-hip circumference ratio between the hypertensive and normotensive groups. Plasma renin activity, aldosterone, epinephrine, and norepinephrine levels were not significantly different between the two groups. Moreover, the correlation between the ratio of the intra-abdominal visceral fat area to subcutaneous fat area ratio and blood pressure was found independent of age and body mass index by multiple regression analyses. We conclude that intra-abdominal fat accumulation itself may play an important role in the pathogenesis of hypertension in obesity. 