ABSTRACT
OBJECTIVES: The beta3 adrenergic receptor(beta3 -AR) may play an important role in the regulation of energy expenditure and lipolysis. A mutation of the beta3 - AR gene(Trp64Arg) has been reported to be associated with early onset of non-insulin dependent diabetes mellitus(NIDDM), obesity and syndrome X which are related with insulin resistance. It is well known that Korean NIDDM patients, in contrast to Caucasians, are mainly non-obese and have experienced severe weight loss during the course of disease. We studied the frequency of the mutation in Korean NIDDM patients and non-diabetics control and evaluated the clinical characteristics of Korean obese NIDDM patients. We investigated the frequency of the mutation in NIDDM patients and clinical characteristics of the patients with the mutation in order to elucidate the significance of the mutation in the pathogenesis of NIDDM in Koreans. METHODS: We studied 401 NIDDM patients and 99 controls. The NIDDM patients were divided into two groups, non-obese group and obese group, according to their body mass index at diagnosis of the disease. The Trp64Arg mutation was detected by the PCR/RFLP method using restriction enzyme Mva I. RESULTS: The Trp64Arg allele frequency(16M) of NIDDM did not differ from that(16%) of controls. Although the mutant allele frequency was not different between non-obese and obese group both in NIDDM patients and controls, the frequency of patient with the mutant allele was significantly higher in obese NIDDM patients than in non-obese NIDDM patients(38.5% vs. 26.9%, P=0.04). However, no significant differences were found in clinical and laboratory findings between the NIDDM patients with the mutant allele and those without the mutant allele. CONCLUSION: These data suggest that beta3 -AR mutation might be associated with Korean obese NIDDM, and other factors might also be associated with the development of obesity and insulin resistance in NIDDM patients.