Increased risk of obesity resulting from the interaction between high energy intake and the Trp64Arg polymorphism of the beta3-adrenergic receptor gene in healthy Japanese men.
BACKGROUND
Few studies have investigated the interaction between the Trp64Arg polymorphism of the beta3-adrenergic receptor gene (ADRB3) and environmental factors. This study aimed to investigate whether energy intake affects the relationship between this polymorphism and obesity.


METHODS
Healthy Japanese men (n=295; age 46.1+/-11.5 years (mean +/-standard deviation); waist circumference 83.9+/-9.3 cm; body mass index (BMI) 23.3+/-3.3 kg/m2) recruited in a Japanese chemical industry firm were eligible for analysis. Daily energy intake, protein, fat, and carbohydrate (PFC) ratio and daily physical activity were assessed by self-reported questionnaires. Genotyping for the polymorphism was performed with written informed consent.


RESULTS
When the subjects were classified into two groups according to presence of the polymorphism, the groups were not significantly different in waist circumference or BMI. Quartile classification of energy intake, however, demonstrated a significantly larger ratio of obese subjects to non-obese subjects in the group with the polymorphism in the highest 4th quartile alone. Multiple logistic regression analysis also revealed that the presence of the polymorphism increased the risk of obesity significantly in the 4th quartile alone (adjusted odds ratio=3.37, 95% confidence interval=1.12-10.2).


CONCLUSIONS
Presence of the polymorphism alone does not significantly increase the risk of obesity. However, high energy intake interacts with the polymorphism and leads to a significant increase in risk of obesity. The Trp64Arg polymorphism of ADRB3 warrants consideration, along with other polymorphisms involved in the development of obesity, for tailor-made prevention of obesity.
Miyaki
Koichi
K
Department of Preventive Medicine and Public Health, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan. miyaki@sc.itc.keio.ac.jp
Sutani
Shinya
S
Kikuchi
Haruhito
H
Takei
Izumi
I
Murata
Mitsuru
M
Watanabe
Kiyoaki
K
Omae
Kazuyuki
K
D015992:Body Mass Index; D002149:Energy Intake; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology* / Q000235:genetics; D011110:Polymorphism, Genetic; D022702:Receptors, Adrenergic, beta-3 / Q000235:genetics*; D012307:Risk Factors; D011795:Surveys and Questionnaires
D022702:Receptors, Adrenergic, beta-3