The beta 3-adrenergic receptor gene and obesity in a population sample of African Americans
Lowe, W.L.; Rotimi, C.N.; Luke, A.; Guo, X.; Zhu, X.; Comuzzie, A.G.; Schuh, T.S.; Halbach, S.; Kotlar, T.J.; Cooper, R.S.
International journal of obesity and related metabolic disorders journal of the International Association for the Study of Obesity 25(1): 54-60
2001
ISSN/ISBN: 0307-0565 PMID: 11244458 Document Number: 539110
OBJECTIVE: To examine the role of the Trp64Arg polymorphism in the beta3-adrenergic receptor gene and the beta3-adrenergic receptor gene locus in obesity-related traits in African Americans. SUBJECTS: A total of 687 individuals representing 193 African American families who were residents of metropolitan Chicago. MEASUREMENTS: Genotyping of the Trp64Arg polymorphism in the beta3-adrenergic receptor gene and three microsatellite markers flanking the beta3-adrenergic receptor gene (ADRB3) locus and measuring various obesity-related traits, including body mass index (BMI), fat-free mass, fat mass, percentage fat mass, waist circumference and serum lipid levels. RESULTS: The prevalence of obesity (defined as body mass index greater than or equal to 30 kg/m2) in the population was 27.3% and 51.2% in men and women, respectively. The frequency of the Arg64 allele was 10.0%. Multivariate regression analyses confirmed the existence of a significant contribution of familial variance to each of the five obesity-related traits noted above. Likelihood ratio statistics computed in a multivariate regression analysis failed to demonstrate a significant association between the Arg64 allele and any of the five obesity-related traits. Single and multipoint analyses using extended Haseman-Elston regression analyses failed to demonstrate suggestive evidence of linkage of three microsatellite markers that flank the beta3-adrenergic receptor gene to BMI, percentage body fat, waist circumference or serum leptin levels. CONCLUSION: Given the contribution of familial variance to obesity-related traits in this population, neither the null finding for the Arg64 allele nor the lack of evidence of linkage of the ADRB3 locus to obesity-related traits could be attributed to lack of transmissibility of the traits suggesting that neither the Arg64 variant of the beta3-adrenergic receptor gene nor another genetic variant in or near the ADRB3 locus contribute significantly to familial aggregation of obesity-related traits in African Americans.