Objective: Epidemiological studies have shown that circulating sex hormone-binding globulin (SHBG) levels are lower in metabolic syndrome (MetS) patients than in non-MetS individuals. In this study, we investigated the relationship of polymorphisms in the SHBG gene with the serum SHBG levels and MetS in Han Chinese.
Methods: We performed a cross-sectional study of 316 subjects who were recruited from a health checkup population at Zhongshan Hospital, Fudan University. Anthropometric measurements, blood pressure, fasting plasma glucose, lipid levels, total testosterone, and SHBG levels were obtained in addition to the seven SHBG single-nucleotide polymorphisms (SNPs).
Results: The variant allele (AG or AA) carriers in rs6259, compared to the wild-type allele carriers (GG), have a lower risk for MetS [OR 0.56, 95% confidence interval (CI) 0.33-0.96] and higher serum SHBG and TT levels (P = 0.016, 0.004). CT or TT allele carriers in rs3760213, compared to CC allele carriers, also have a lower risk for MetS (OR 0.59, 95 % CI 0.34-1.00) and significantly higher SHBG and TT levels (P = 0.029, 0.009). Carriers having both of the variant alleles had the lowest risk of MetS (OR 0.51, 95 % CI 0.275-0.950) and the highest SHBG levels. The risk of MetS rose with the decrease in serum SHBG levels for rs6259 and rs376021 carriers.
Conclusion: rs6259 and rs3760213 SNPs are associated with the risk of MetS and lower serum SHBG level in Chinese Han males.