Improvement in left ventricular function after rapid weight loss in obesity

The effect of rapid weight reduction on left ventricular function and blood pressure was studied in 34 obese subjects, who all weighed more than 30% above their ideal body weight. Subjects with co-existing hypertension (N = 15) and proven coronary artery disease (N = 9) were included to assess contributions from these factors. Blood pressure (BP) was measured both indirectly and by direct ambulatory intra-arterial methods. Radionuclide ventriculography was performed at rest and at exercise, before and after dieting, which was supervised in hospital (daily intake 330 kCal day-1 for 4 weeks). Dieting induced a weight loss of (mean +/- SD) 9.6 +/- 3.5 kg (P less than 0.0001) in the whole group. The mean daytime intra-arterial blood pressure fell from 157 +/- 23/90 +/- 15 to 144 +/- 21/85 +/- 13 mmHg (P less than 0.0001). The fall in ambulatory intra-arterial diastolic blood pressure did not reach significance in the normotensive and ischaemic groups. The mean resting left ventricular ejection fraction (LVEF) in the whole group showed a significant reduction after weight loss from 61 +/- 10% to 56 +/- 6% (P less than 0.005). Although the individual groups showed a fall in LVEF, the effect was most marked in the hypertensive group, from 65 +/- 9% to 57 +/- 5% (P less than 0.002). Before dieting none of the groups achieved a 'normal' 5% rise in LVEF above basal in response to exercise, the hypertensive and the ischaemic groups both showing non-significant falls. This phenomenon was, however, reversed after weight loss.(ABSTRACT TRUNCATED AT 250 WORDS)