Objective: To investigate the distribution of SNP276 in adiponectin gene in Chinese Hans and its impact on type 2 diabetes mellitus and insulin sensitivity.
Methods: The study population consisted of 417 Chinese Hans residents in Anhui province, including 141 subjects with normal glucose tolerance (NGT) and 276 with type 2 diabetes (T2DM). The islet beta-cell insulin secretion and tissue insulin sensitivity were assessed by formulae of homeostasis model assessment (HOMA-IR & HOMA beta). Firstly, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to determine whether variation exists in APM1. Then, exact variation was detected by automated DNA direct sequencing.
Results: The genotypes of APM1 SNP276 were 0.489 GG, 0.418 GT and 0.092 TT and the major allele was G (frequency=0.699) in subjects with NGT. The distributions of genotypes and alleles of SNP276 both displayed significant difference between NGT and T2DM groups (P=0.031 and 0.013). The SNP276 non-TT (TG+GG) genotype was associated with increased risk of T2DM (OR=2.447, 95%CI: 1.067-5.612, P=0.035). In T2DM group, the subjects with SNP276 GG or GT genotype had higher body mass index, body fat content, fasting plasma glucose and HOMA-IR than did those with TT genotype (P < 0.05 or P < 0.01). Besides, GG genotype had higher systolic blood pressure (P=0.021). In NGT group, SNP276 non-TT carrier had increased body mass index, body fat content, waist hip ratio, fasting plasma insulin, oral glucose tolerance test 2 h plasma insulin and HOMA-IR when compared with TT genotype (P < 0.05 or 0.01).
Conclusion: SNP276 in APM1 was associated with T2DM and insulin sensitivity.