Effect of weight loss on blood pressure, arterial compliance, and insulin resistance in normotensive obese subjects.

BACKGROUND

Obesity is characterized by insulin resistance and hyperinsulinemia that may elevate arterial pressure due to sympathetic overactivity and volume overload. The aim of the study is to measure hemodynamic parameters and metabolic variables in obese normotensive subjects.

METHODS

Twenty-four normotensive, overweight subjects from our medical staff were enrolled. They had personal and group meetings with a physician, dietician, and psychologist to improve their compliance with regard to physical activity and personal low-calorie diet. In addition, each subject was given orlistat 120 mg three times daily for 12 weeks. Noninvasive hemodynamic parameters including arterial compliance were measured using radial artery pulse wave analysis, at the beginning and 1 month after taking the last dose of Orlistat, and insulin resistance was calculated using HOMA score.

RESULTS

At the end of the 3-month period, the average weight was reduced from 89.5 +/- 12 kg to 81.5 +/- 9 kg. The systolic arterial pressure was reduced from 128 +/- 12 mm Hg to 121 +/- 10 mm Hg and diastolic arterial pressure was reduced from 75.4 +/- 9 mm Hg to 69.6 +/- 7 mm Hg. Arterial compliance measurements showed significant improvement in large artery compliance from 13 +/- 4 to 15.8 +/- 3.6 while no change occurred in small arteries. The insulin sensitivity assessed by HOMA score improved significantly from 6.5 +/- 4.5 to 4.8 +/- 3.1 with weight reduction.

CONCLUSIONS

Our data show that weight loss is accompanied by lowering of blood pressure, even in normotensive obese patients. This weight loss brings about an improvement in insulin resistance and a rise in large artery compliance, whereas no change occurs in small artery compliance.