Effect of β3-adrenergic receptor gene polymorphism and lifestyle on overweight Japanese rural residents: A cross-sectional study

Objectives: The β3-adrenergic receptor (ADRB3) gene polymorphism has been implicated in obesity. Therefore, the contribution of ADRB3 Trp64Arg polymorphism to obesity-related indicators was investigated, taking into account the lifestyle-related factors in a Japanese rural population. Methods: A total of 600 Japanese adults aged ≥40 years in a population-based cohort study were analyzed. The ADRB3 polymorphism was determined using peripheral blood samples. Associations between genotype and body mass index (BMI), waist circumference (WC), and body fat (BF) percentage were examined, adjusting for lifestyle-related factors, including daily nutrient intake. Results: The frequency of Arg64 allele carriers was 36%. There was no significant difference in BMI, WC, or BF between the groups with or without the Trp64Arg polymorphism. Multivariable logistic regression analysis showed that the Trp64Arg polymorphism was not associated with these three indicators, but lifestyle factors including physical inactivity, higher energy and sodium consumption, and less animal protein intake were significantly related to increased WC and BF percentages. Conclusions: The Trp64Arg polymorphism of ADRB3 gene did not contribute to increased BMI, WC, or BF. However, lifestyle-related factors impacted these indicators in middle-aged and older Japanese individuals living in rural areas.