METABOLIC AND CARDIOVASCULAR ASSESSMENT IN MODERATE OBESITY - EFFECT OF WEIGHT-LOSS

Metabolic and hemodynamic abnormalities have been separately described in obesity, and weight reduction is known to lead to some improvement in each. Our aim was to simultaneously assess metabolic and cardiovas cular function in normotensive, normotolerant patients with moderate o besity (body mass index = 32.6 +/- 1.1 kg/m(2)) before and after weigh t loss. The obese were insulin resistant [37.4 +/- 4.8 mu mol/min.kg F FM; P < 0.02 vs. 12 lean controls (50.6 +/- 2.6), on a euglycemic insu lin clamp], secreted more insulin both in the fasting state and after oral glucose (70 +/- 10 us. 48 +/- 6 nmol/mmol.L plasma glucose; P < 0 .05), and had higher resting energy expenditure (4.62 +/- 0.18 us. 4.0 0 +/- 0.23 kJ/min), systolic and mean blood pressure, stroke volume (8 7 +/- 8 us. 67 +/- 4 mL/min; P = 0.05), and cardiac output. There was, however, no relationship between the metabolic and hemodynamic abnorm alities. After a weight loss of 11 +/- 1 kg (similar to 15%), insulin sensitivity improved in proportion to the weight reduction, whereas in sulin hypersecretion and high energy expenditure persisted. In contras t, all hemodynamic changes reverted to normal. We conclude that in mod erate obesity, the metabolic and cardiovascular abnormalities are larg ely independent of one another; accordingly, weight loss affects them differentially. Partial weight normalization may provide sufficient ca rdiovascular protection.