January 2001, Volume 25, Issue 1, Pages 54 - 60

Paper

The 3-adrenergic receptor gene and obesity in a population sample of African Americans WL Lowe Jr1, CN Rotimi2, A Luke2, X Guo2, X Zhu2, AG Comuzzie3, TS Schuh1, S Halbach2, TJ Kotlar1 & RS Cooper2 1Department of Medicine, Northwestern University Medical School and VA Chicago Healthcare System, Lakeside Division, Chicago, Illinois, USA     2Department of Preventive Medicine, Loyola University Medical Center, Maywood, Illinois, USA     3Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas, USA     Correspondence to: WL Lowe Jr, Center for Endocrinology, Metabolism, and Molecular Medicine, Tarry 15-703, Northwestern University Medical School, 303 East Chicago Ave, Chicago, IL 60611, USA. E-mail: wlowe@nwu.edu

Keywords

African American;   3-adrenergic receptor;   leptin;   genetics

Abstract

OBJECTIVE: To examine the role of the Trp64Arg polymorphism in the 3-adrenergic receptor gene and the 3-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 3-adrenergic receptor gene and three microsatellite markers flanking the 3-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 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 3-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 3-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. International Journal of Obesity (2001) 25, 54-60

Received 14 March 2000; Accepted 4 July 2000

^© Macmillan Publishers Ltd 2001