Objective: To compare the clinical features associated with the Trp64Arg mutation of the beta 3-adrenergic receptor (beta 3AR) gene between the Chinese and Japanese, the BMI, blood pressure, heart rate and plasma lipoproteins in the 2 cohorts. were investigated.
Methods: Two groups of Chinese patients including 614 non-diabetes (ND) (group 1) and 137 NIDDM (group 2), and 2 groups of Japanese patients including 746 health check people in Hachijo Island (group A) and 371 outpatients with diabetes or/and hyperlipidemia (group B) were investigated. PCR for the Trp64Arg mutation in the beta 3-adrenergic receptor (beta 3AR) gene was performed in all subjects.
Results: (1) The allelic frequency of the Trp64Arg mutation was 19.7% in NIDDM and 17.4% in ND group, mean 17.8% in the Chinese, and 23% in the group A and 18.3% in the group B, mean 21.7% in the Japanese. (2) The frequency of Trp64Arg mutation in the beta 3AR gene was gradually increased with the increase in BMI in the Chinese and the significance was shown in women between BMI < 25 and BMI > 28 (15.9% vs. 29.1%, P < 0.02). The Trp64Arg genotypes of the beta 3AR had a significantly higher BMI compared with Trp64Trp genotype in the Chinese (P < 0.001 and 0.002, respectively). But no significant differences were found in the Japanese. (3) A significant lower total cholesterol in Arg64Arg than in Trp64Trp was seen in Japanese men (P = 0.03), and in both Arg64Arg and Trp64Arg in Chinese men (P < 0.001 and P < 0.005). (4) Slightly higher systolic blood pressure was observed in Arg64Arg than in Trp64Trp in Japanese men (P = 0.0 026), and significantly higher heart rate in Arg64Arg than Trp64Arg and Trp64Trp in Chinese (P < 0.001). (5) HDL-C was significantly lower in Arg64Arg than in Trp64Trp in the Chinese, (P < 0.001).
Conclusion: The Trp64Arg Department of Metabolic Diseases, Faculty of Medicine, University of Tokyo (Yoko Iizuka, Shun Ishibashi, Takanari Gotoda), Institute of Clinical Medicine University of Tsukuba, Tsukuba, Japan (Nobuhiro Yamada) mutation in beta 3-adrenergic receptor gene contributes to the increased body weight in the Chinese, especially in older women, but not in the Japanese, and to the lower plasma total cholesterol levels in both Chinese and Japanese men, and it potentially contributes to higher systolic blood pressure, faster heart rate and lower HDL-c as well.