Abstract
Objectives: To examine the effects of β3-adrenergic receptor gene polymorphism on body weight change during a weight reduction program for middle-aged, overweight women with careful consideration of their energy intake and expenditure.
Methods: Design: Intervention study of weight reduction for 12 weeks in a community setting. Subjects: Eighty overweight middle-aged women who completed the individualized lifestyle modification program. Measurements: β3-adrenergic receptor gene polymorphism was identified by polymerase chain reaction and consecutive restriction fragment-length polymorphism analysis. Anthropometrical parameters, lifestyle factors, blood lipid and glucose levels, physical activity level and energy intake were measured before and at the end of the program.
Results: The numbers of subjects with the Trp64Trp, Trp64Arg, and Arg64Arg genotypes were 45, 30 and 5, respectively. Baseline characteristics among subjects with the Trp64Trp, Trp64Arg and Arg64Arg alleles did not differ. After 12 weeks, the subjects with the 64Arg allele had significantly smaller decrease in body weight and energy intake than those without the 64Arg allele. The change of other clinical characteristics did not differ between the two groups. After adjusting for the %change of energy intake, the %change of body weight did not differ between the two groups.
Conclusion: The 64Arg allele of the β3-AR gene is not likely to be the factor determining the difficulty in losing body weight in Japanese middle-aged, overweight women. Lifestyle factors, such as the decrease in energy intake, might mask the effect of the 64Arg allele on body weight loss. Specific considerations for the management of energy intake would be needed to promote body weight loss for those with the 64Arg allele.
