BACKGROUND: Polymorphism of Trp64Arg in the beta(3)-adrenergic receptor (beta(3)-AR) gene may play a critical role in lipid and lipoprotein metabolism by mediating lipolysis and thermogenesis. Since the frequency of Arg alleles of the beta(3)-AR gene is generally low among many populations, studies on the Arg/Arg genotype in relation to lipid and lipoprotein metabolism are required in countries such as Japan which has a relatively high frequency of the Arg allele. METHODS: We genotyped 275 clinically healthy Japanese (male/female, 134/141, mean 45.7 years) without medication for beta(3)-AR gene polymorphism by polymerase chain reaction-restriction fragment length polymorphism analysis, and investigated the effects of the gene polymorphism on clinical parameters including body mass index (BMI), blood pressure and serum lipid and lipoprotein concentrations. RESULTS: The genotype frequencies were: Trp/Trp, 68.0%; Try/Arg, 28.0% and Arg/Arg, 4.0%, with an allele frequency of 0.18 for Arg64. When subjects were divided into three groups according to the genotype, a significant increase of serum LDL-cholesterol (LDL-C) concentration in the Arg/Arg group (3.48 +/- 1.59 mmol/L) was observed when compared with those of the Trp/Trp and Arg/Trp groups (3.15 +/- 0.80, 3.25 +/- 0.92 mmol/L, respectively). Genotype differences did not show any significant effect on other parameters. Spearman's rank correlation demonstrated a significant relationship between LDL-C concentrations and the number of Arg alleles, age and BMI. Multiple regression analysis, using LDL-C concentration as a criterion variable and some factors including beta(3)-AR gene polymorphism as explanatory variables, revealed that the number of Arg alleles was a significant and independent factor for LDL-C concentrations, along with age and BMI. CONCLUSIONS: These findings suggested a role of the beta(3)-AR gene polymorphism in regulating lipid and lipoprotein metabolism, showing small but significant effects on elevated LDL-C values in subjects with Arg/Arg, but not Trp/Arg and Trp/Trp genotypes.
BACKGROUND: Polymorphism of Trp64Arg in the beta(3)-adrenergic receptor (beta(3)-AR) gene may play a critical role in lipid and lipoprotein metabolism by mediating lipolysis and thermogenesis. Since the frequency of Arg alleles of the beta(3)-AR gene is generally low among many populations, studies on the Arg/Arg genotype in relation to lipid and lipoprotein metabolism are required in countries such as Japan which has a relatively high frequency of the Arg allele. METHODS: We genotyped 275 clinically healthy Japanese (male/female, 134/141, mean 45.7 years) without medication for beta(3)-AR gene polymorphism by polymerase chain reaction-restriction fragment length polymorphism analysis, and investigated the effects of the gene polymorphism on clinical parameters including body mass index (BMI), blood pressure and serum lipid and lipoprotein concentrations. RESULTS: The genotype frequencies were: Trp/Trp, 68.0%; Try/Arg, 28.0% and Arg/Arg, 4.0%, with an allele frequency of 0.18 for Arg64. When subjects were divided into three groups according to the genotype, a significant increase of serum LDL-cholesterol (LDL-C) concentration in the Arg/Arg group (3.48 +/- 1.59 mmol/L) was observed when compared with those of the Trp/Trp and Arg/Trp groups (3.15 +/- 0.80, 3.25 +/- 0.92 mmol/L, respectively). Genotype differences did not show any significant effect on other parameters. Spearman's rank correlation demonstrated a significant relationship between LDL-C concentrations and the number of Arg alleles, age and BMI. Multiple regression analysis, using LDL-C concentration as a criterion variable and some factors including beta(3)-AR gene polymorphism as explanatory variables, revealed that the number of Arg alleles was a significant and independent factor for LDL-C concentrations, along with age and BMI. CONCLUSIONS: These findings suggested a role of the beta(3)-AR gene polymorphism in regulating lipid and lipoprotein metabolism, showing small but significant effects on elevated LDL-C values in subjects with Arg/Arg, but not Trp/Arg and Trp/Trp genotypes.