Influence of sibutramine on energy expenditure in African American women.
OBJECTIVE
African American women have a high prevalence of obesity, which partially may be explained by their lower rates of resting energy expenditure (REE). The aim of this study was to examine the influence of acute sibutramine administration on REE and post-exercise energy expenditure in African American women.


METHODS
A total of 15 premenopausal, African American women (age, 29 +/- 5 years; body fat, 38 +/- 7%) completed a randomized, double-blind cross-over design with a 30-mg ingestion of sibutramine or a placebo. Each trial was completed a month apart in the follicular phase and included a 30-minute measurement of REE 2.5 hours after sibutramine or placebo administration. This was followed by 40 minutes of cycling at approximately 70% of peak aerobic capacity and a subsequent 2-hour measurement of post-cycling energy expenditure.


RESULTS
There was no difference (p > 0.05) in REE (23.70 +/- 2.81 vs. 23.69 +/- 2.95 kcal/30 min), exercise oxygen consumption (1.22 +/- 0.15 vs. 1.25 +/- 0.15 liter/min), and post-cycling energy expenditure (104.2 +/- 12.7 vs. 104.9 +/- 11.4 kcal/120 min) between the sibutramine and placebo trials, respectively. Cycling heart rate was significantly higher (p = 0.01) during the sibutramine (158 +/- 14 beats/min) vs. placebo (150 +/- 12 beats/min) trials.


CONCLUSIONS
These data demonstrate that acute sibutramine ingestion does not increase REE or post-exercise energy expenditures but does increase exercising heart rate in overweight African American women. Sibutramine may, therefore, impact weight loss through energy intake and not energy expenditure mechanisms.
Starling
R D
RD
Department of Geriatricsm University of Arkansas for Medical Sciences, Little Rock 72205, USA. starlingraymondd@uams.edu
Liu
X
X
Sullivan
D H
DH
D000328:Adult; D001067:Appetite Depressants / Q000494:pharmacology*; D001481:Basal Metabolism / Q000187:drug effects; D044383:Black People / Q000235:genetics; D018592:Cross-Over Studies; D003503:Cyclobutanes / Q000494:pharmacology*; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects* / Q000235:genetics; D015444:Exercise / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D009765:Obesity / Q000188:drug therapy* / Q000235:genetics; D010101:Oxygen Consumption / Q000187:drug effects; D017697:Premenopause; D001741:Black or African American
D001067:Appetite Depressants; D003503:Cyclobutanes; C058254:sibutramine