Objective: To investigate the relationship between Trp64Arg mutation in beta(3)-adrenergic receptor (beta(3)-AR) gene and the incidence of metabolic syndrome (MS).
Methods: A seven-year follow-up study was conducted in 386 simple obese subjects and 175 normal weight subjects in whom geno-typing of Trp64Arg mutation in beta(3)-AR gene was examined in 2000.
Results: There were no differences between a Trp64Trp homozygote group and a Trp64Arg heterozygote group of whether obese or normal weight subjects with respect to adiposity, blood pressure, lipid profile, fasting blood glucose and fasting insulin in the baseline. The results of follow-up indicated that the incidence of MS in the Trp64Arg heterozygote group was higher than that in the Trp64Trp homozygote group of obese males (54.76% vs 40.85%, P < 0.05) but not in the group of obese females. The incidences of MS both in the Trp64Trp homozygote group and Trp64Arg heterozygote group were higher in obese males than in obese females (40.85% vs 18.27% and 54.76% vs 21.28%, all P < 0.01). No significant differences were found in incidences of MS both in the Trp64Trp homozygote group and Trp64Arg heterozygote group of normal weight subjects whether the comparison was made between males and females respectively or between males and females. The overall incidence of MS in the obese subjects were significantly increased than that in the normal weight subjects whether there was gene variant or not (31.30% vs 6.03% and 42.75% vs 12.73%, all P < 0.01). Logistic analysis showed that beta(3)-AR gene variant was associated with increased incidence of MS in males.
Conclusion: beta(3)-AR gene Trp64Arg mutation is an independent risk factor for the incidence of MS in males.