Decrease in Intra-Abdominal Visceral Fat May Reduce Blood Pressure in Obese Hypertensive Women

We investigated the relationship between changes in blood pressure and fat distribution after a 12-week low-calorie diet in 26 obese hypertensive women whose average age was 50 +/- 13 years, mean body mass index was 33.7 +/- 3.1 kg/m2, and mean blood pressure was 112 +/- 9 mm Hg. As an index of intra-abdominal fat accumulation, we used the ratio of the intra-abdominal visceral fat area to subcutaneous fat area, determined by a computed tomographic section at the level of the umbilicus. Subjects lost a mean of 9.4 +/- 4.1 kg on a 1200-kcal (5040-kJ) diet for 12 weeks. Their mean blood pressure fell from 112 +/- 9 to 101 +/- 12 mm Hg (P < .001). The ratio of the visceral to subcutaneous fat area was significantly reduced after weight reduction from 0.56 +/- 0.33 to 0.45 +/- 0.27 (P < .02). Fasting plasma glucose and plasma glucose area after a 75-g oral glucose tolerance test also were significantly reduced by weight reduction. The change in mean blood pressure after weight reduction was not correlated with the change in body weight or body mass index but was correlated with the reduction in visceral fat area or ratio of visceral fat to subcutaneous fat area. Changes in mean blood pressure also were correlated with changes in fasting plasma glucose levels and the plasma glucose area determined by 75-g oral glucose tolerance test. Results indicate that a decrease in intra-abdominal visceral fat, rather than simply of body weight, may reduce blood pressure in obese hypertensive subjects. The mechanism may involve an improvement in glucose tolerance caused by weight reduction.