Racial differences in the relation between uncoupling protein genes and resting energy expenditure

• Published in: The American journal of clinical nutrition Vol. 75; no. 4; pp. 714 - 719
• Main Authors: KIMM, Sue Y. S, GLYNN, Nancy W, ASTON, Christopher E, DAMCOTT, Coleen M, POEHLMAN, Eric T, DANIELS, Stephen R, FERRELL, Robert E
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.04.2002; American Society for Clinical Nutrition, Inc
• Subjects: Absorptiometry, Photon; Adult; African Continental Ancestry Group; Basal Metabolism - genetics; Biological and medical sciences; Body Mass Index; Calorimetry, Indirect; Carrier Proteins - genetics; European Continental Ancestry Group; Female; Fundamental and applied biological sciences. Psychology; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Genotype; Human; Humans; Ion Channels; Longitudinal Studies; Medical sciences; Membrane Proteins - genetics; Membrane Transport Proteins; Metabolic diseases; Metabolism; Mitochondrial Proteins; Obesity; Obesity - genetics; Population genetics, reproduction patterns; Proteins; Proteins - genetics; Race; Uncoupling Protein 1; Uncoupling Protein 2; Uncoupling Protein 3; Women; Human; Obesity; Energy metabolism; Uncoupling protein; Genetic variability; Nutrition disorder; Basal metabolism; Population genetics; Genetic determinism; Energetic cost; Young adult; Race; Caucasoid; Nutritional status; Comparative study; African American; Polymorphism
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/75.4.714

Lower resting energy expenditure (REE) in African American women may contribute to their obesity. The identification of uncoupling protein (UCP) genes has fueled a search for genes involved in energy metabolism in humans. We examined variation in REE in relation to variation in UCP1, UCP2, and UCP3 in 141 women aged 18-21 y. Standard methods were used for REE measurements and genetic analysis. Body composition was determined with the use of dual-energy X-ray absorptiometry. Multivariate analysis was used to examine the effect of genotypes on REE and on fat mass in relation to other potentially confounding variables. REE was 295 kJ/d lower in African American women than in white women. No significant variation in REE was seen for UCP1, UCP2, and UCP3 (p-55; exon 3a; and exon 3b) variants after adjustment for other variables including smoking status. For the UCP3 exon 5 variant, REE was significantly (P = 0.019) lower in African American women with the CC genotype than in those with the TT genotype. In African American women, there was a significant trend (P = 0.012) toward lower REE and a weak but nonsignificant trend (P = 0.1) toward greater fat mass across the 3 genotypes (TT, CT, and CC). The significant and dose-dependent relation between lower REE and the C allele suggests that it may be a thrifty allele. The presence of this parsimonious energy metabolism in African American women, possibly linked to UCP3, may be implicated in their susceptibility to obesity. The absence of a UCP3 effect in white women is intriguing and needs to be explored to further understand possible interactions between UCP3 and other genes.