Polymorphisms of beta-2 adrenergic receptor gene in Koreans with obesity and noninsulin-dependent diabetes mellitus(NIDDM)

Kim, Sung Hoon; Kim, Byoung Joon; Kim, Dong Jun; Hahm, Jong Ryeal; Ahn, Kyu Jeong; Chung, Jae Hoon; Min, Yong Ki; Lee, Myung Shik; Kim, Kwang Won; Kim, Young Seol; Choi, Young Kil

Abstract

OBJECTIVE
Catecholamine play a central role in the regulation of energy expenditure, in part by stimulating lipid mobilization through lipolysis in fat cells. The beta-2 adrenergic receptor(BAR-2) is a major lipolytic receptor in human fat cells. A recent study has shown that common polymorphisms occuring at codon 16 and 27 of the BAR-2 gene are significantly associated with obesity and lypolytic BAR-2 function in adipose tissue. We investigated whether the previously described human BAR-2 gene polymorphisms are associated with obesiy and NIDDM in Koreans.
METHODS
All subjests were divided into two groups, non-obese and obese group, according to their body mass index. And their clinical characteristics were evaluated. The BAR-2 gene polymorphisms were analyzed by PCR-RFLP in 89 nondiabetics and 106 patients with NIDDM.
RESULTS
When the allele frequency of BAR-2 gene polymorphisms was compared with that of western people, there was a significant difference. In our study, there was no significant difference in the allele frequency of BAR-2 gene polymorphisms at codons 16 and 27 between nonobese and obese group both nondiabetics and NIDDM subjects. The frequency of Glu27 homozygotes was very rare(1.1%). Body mass index(BMI), waist-hip ratio(WHR), and serum glucose and insulin secretion of the nondiabetics with polymorphism of codon 16 or codon 27 did not differ from those of the subjects without the polymorphisms. In NIDDM group, the Gly16 homozygotes had a lower BMI than Arg16 homozygotes without any difference in WHR and the other laboratory parameters. Neither clinical or laboratory parameters of the diabetics with the polymorphism at codon 27 differ from those of subjectes without the polymorphism. CONCLUSION: These findings suggest that the genetic variability in the human BAR-2 gene is not a major determinant for the development of obesity and NIDDM in Koreans.