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

Objective : This study was conducted to address the question of whether theβ3-adrenergic receptor gene mutation (Trp 64 Arg) is associatedwithmetabolicdiseaseinJapanesepatients 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. Anthro- pometrics variables and biochemical parameters were compared among the genotypes. Results : The64Arg 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 64 Arg allelic mutation is not associated with obesity, type 2 diabetes mellitus, lipid metabolism dysfunction, or hypertension in Japanese patients with schizophrenia. J. Med. Invest. 52 : 57-64, February, 2005