Body composition and metabolic effects of a diet and exercise weight loss regimen on obese, HIV-infected women.

HIV has classically been a wasting disease. However, in the United States, obesity is increasingly common among HIV-infected individuals receiving effective antiviral treatment. The risks of obesity are unclear in HIV, although the increased prevalence of diabetes and cardiovascular disease in the presence or absence of obesity causes growing concern. This study aimed to assess the effects of weight loss (through energy restriction combined with aerobic and resistance exercise) on body composition, body fat distribution, resting energy expenditure, quality of life (QOL), strength and fitness, and metabolic risk factors in obese, HIV-infected women. Eighteen HIV-infected women with a body mass index of 30 or more completed a 12-week weight loss program. Before and after the intervention, body composition and fat distribution by dual energy x-ray absorptiometry and whole-body magnetic resonance imaging, resting energy expenditure by indirect calorimetry, QOL, strength, and fitness were measured. Insulin sensitivity by intravenous glucose tolerance test and circulating cardiovascular risk factors (including lipids, tissue plasminogen activator, and plasminogen activator inhibitor 1) were measured in a subset (n = 9). Daily food intake and total body weight decreased (mean +/- SD) by 3195 +/- 477 kJ and 6.7 +/- 4.2 kg, respectively. Weight lost was 95.5% fat by dual energy x-ray absorptiometry or 6.2 L of subcutaneous adipose tissue, 0.7 L visceral adipose tissue, and 0.8 L skeletal muscle by magnetic resonance imaging. Resting energy expenditure fell approximately 419 kJ, strength and fitness increased by 28.9% +/- 18.5% and 36.8% +/- 41.6%, respectively, and QOL improved in 11 of 13 dimensions. There was significant insulin resistance in the subset with metabolic measurements at baseline, and at follow-up there was no improvement in fasting glucose, insulin, or insulin sensitivity, nor was there any change in fasting lipids, tissue plasminogen activator, or plasminogen activator inhibitor 1. There was no significant change in CD4 count or HIV viral load. In conclusion, moderate weight loss achieved by a short-term program of diet and exercise in obese HIV-positive women appears safe and induces loss of adiposity in both the subcutaneous adipose tissue and visceral adipose tissue regions. Despite reduced food intake, weight and fat loss, as well as improvements in strength, fitness, and QOL, the lack of improvement in metabolic parameters suggests that additional interventions may be necessary to reduce the risk of diabetes and cardiovascular disease in this population.

Left ventricular function during strength testing and resistance exercise in patients with left ventricular dysfunction.

PURPOSE: Deterioration in left ventricular function is a more sensitive marker of myocardial ischemia during exercise than ST segment depression. The current study was designed to evaluate left ventricular function during one-repetition-maximum (1-RM) strength testing and resistance exercise in cardiac patients with moderate left ventricular dysfunction. METHODS: Using echocardiographic methods, left ventricular function was evaluated in 15 patients with left ventricular dysfunction (age, 65 +/- 6.5 years; ejection fraction, 42.1 +/- 5.8). Measurements were performed during 1-RM testing and resistance exercise (20%, 40%, and 60% of 1-RM using 10 to 15 repetitions) on the one-arm biceps curl (BIC) and bilateral knee extension exercises and compared with measurements of left ventricular function during the symptom-limited graded exercise test (SL-GXT). RESULTS: During the knee extension exercise, there was a slight but significant reduction (P< or =.05) in ejection fraction values at the end of 60% 1-RM, as compared with rest and previous workloads. Significant increases in systolic blood pressure and left ventricular end-systolic volume ratio values (P< or =.05) from rest to exercise were observed across test modes and for all workloads. The prevalence of new wall motion abnormalities during knee extension and BIC 1-RM strength testing was comparable with that observed during SL-GXT. The greatest increase in new wall motion abnormalities was seen during 60% 1-RM of knee extension exercise, as compared with prior workloads, BIC exercises, and SL-GXT. CONCLUSIONS: Despite an increase in occurrence of ischemic changes during the highest resistance exercise workloads and with larger muscle mass, the findings are small in magnitude and do not suggest reduced cardiac performance.