Relationship of leptin, resting metabolic rate, and body composition in pre-menopausal Hispanic and non-Hispanic White women
Understanding metabolic and hormonal influences on energy expenditure among pre-menopausal women may help discern factors that influence racial/ethnic disparities in overweight and obesity among women. Purpose. To evaluate the relationship between fasting serum leptin, resting metabolic rate (RMR), and body composition in pre-menopausal Hispanic and non-Hispanic White (White) women. Methods. Participants were 67 Hispanic [mean ± SE age: 42.8 ± 0.6 y; ht: 161.5 ± 0.6 cm; mass: 69.7 ± 1.8 kg; BMI: 26.7 ± 0.7 kg/m2] and 43 White [age: 43.4 ± 0.6 y; ht: 165.5 ± 1.0 cm; mass: 66.6 ± 1.9 kg; BMI: 24.3 ± 0.6 kg/m2] women. Participants arrived at the lab in a fasted state for measurement of RMR by indirect calorimetry. Bone mineral content was measured by DXA and body density was determined by hydrodensitometry. Percentage of body fat was estimated using a 3-compartment equation (Lohman, 1986). Serum leptin levels were determined by EIA. Results. Overall, a strong correlation was observed between leptin and fat mass (FM) (r = 0.51; P < 0.001). When separated by race, Hispanics showed a strong correlation (r = 0.62; P < 0.001), while Whites showed a weak correlation (r = 0.16; P > 0.05) between leptin and FM. There was a moderate correlation between leptin and RMR (r = 0.36; P < 0.001) for both groups combined. Hispanic women demonstrated a moderate correlation (r = 0.47; P < 0.001), while White women demonstrated no correlation (r = 0.07; P > 0.05) between leptin and RMR. There was a high correlation (r = 0.71; P < 0.001) between RMR and lean body mass (LBM) for both groups combined. Independently, both Hispanics and Whites showed a strong correlation (r = 0.70, 0.76, respectively; P < 0.001) between RMR and LBM. Multiple regression analysis revealed that body mass and LBM were the best predictors of RMR. Leptin was not a significant predictor of RMR. Conclusion. These data indicate that leptin was not a predictor of RMR in pre-menopausal Hispanic women. However, body mass and LBM was associated with RMR for both Hispanic and White women. Further research examining the relationship between leptin and energy expenditure is needed.^
Deemer, Sarah E, "Relationship of leptin, resting metabolic rate, and body composition in pre-menopausal Hispanic and non-Hispanic White women" (2008). ETD Collection for University of Texas, El Paso. AAI1453838.