Low Fitness Partially Explains Resting Metabolic Rate Differences Between African American and White Women

作者：Shook Robin P^*; Hand Gregory A; Wang Xuewen; Paluch Amanda E; Moran Robert; Hebert James R; Swift Damon L; Lavie Carl J; Blair Steven N

来源：American Journal of Medicine, 2014, 127(5): 436-442.

DOI：10.1016/j.amjmed.2014.02.003

• Fitness
• Physical activity
• Race
• Resting metabolic rate
• Women

BACKGROUND: High levels of obesity among African American women have been hypothesized to be partially resultant from a lower resting metabolic rate compared with white women. The aim of the current study was to determine if differences in cardiorespiratory fitness and moderate-to-vigorous physical activity are associated with differences in resting metabolic rate among free-living young adult African American women and white women. %26lt;br%26gt;METHODS: Participants were 179 women (white women n = 141, African American women n = 38, mean age = 27.7 years). Resting metabolic rate was measured using indirect calorimetry, body composition using dual energy x-ray absorptiometry, cardiorespiratory fitness via maximal treadmill test, and moderate-tovigorous physical activity using an activity monitor. %26lt;br%26gt;RESULTS: African American women had higher body mass index, fat mass, and fat-free mass compared with white women but lower levels of cardiorespiratory fitness. No differences were observed between African American and white women in resting metabolic rate when expressed as kcal/day (1390.8 +/- 197.5 vs 1375.7 +/- 173.6 kcal/day, P.64), but African American women had a lower resting metabolic rate when expressed relative to body weight (2.56 +/- 0.30 vs 2.95 +/- 0.33 mL/kg/min, P %26lt;.001). After statistical adjustment for differences in body composition between groups using linear regression models, African American women had a lower resting metabolic rate compared with white women (1299.4 +/- 19.2 vs 1400.4 +/- 9.2 kcal/day, P %26lt;.001). The addition of cardiorespiratory fitness reduced the differences among groups by 25%. The addition of moderate-to-vigorous physical activity did not improve the model. %26lt;br%26gt;CONCLUSIONS: The present study confirms that African American women have a lower resting metabolic rate compared with their white peers, and low cardiorespiratory fitness explained 25% of this difference. Variables associated with resting metabolic rate, such as cardiorespiratory fitness, represent possible points of tailored interventions designed to address high levels of obesity seen in certain demographic groups.

• 出版日期2014-5