No association of the Trp 64 Arg mutation of the β3-adrenergic receptor gene with obesity, type 2 diabetes mellitus, hyperlipidemia, and hypertension in Japanese patients with schizophrenia

This study was conducted to address the question of whether the β3-adrenergic receptor gene mutation (Trp 64 Arg) is associated with metabolic disease in Japanese patients with schizophrenia. Methods : In a cross-sectional study, 89 participants were grouped into three genotypes. The 64 Arg allelic frequency in patients with or without metabolic disease was analyzed. Anthropometrics variables and biochemical parameters were compared among the genotypes. Results : The 64 Arg allele, which had a frequency of 0.22, was not associated with obesity, type 2 diabetes mellitus, dyslipidemias, or hypertension. No significant differences among the genotypes were found in current age, age at diagnosis with schizophrenia, body mass index, waist-hip ratio, plasma glucose, plasma insulin, triglycerides, free fatty acids. Patients with the 64 Arg allele had greater 24-h excretion of norepinephrine than those lacking the variant (p=0.019). Conclusion : The 64Arg allelic mutation is not associated with obesity, type 2 diabetes mellitus, lipid metabolism dysfunction, or hypertension in Japanese patients with schizophrenia.