[Association of STEAP4 genetic polymorphisms with insulin resistance in Uygur Chinese general population]

To explore the relationship between six-transmembrane epithelial antigen of prostate 4 (STEAP4) genetic polymorphisms and insulin resistance (IR) in Uygur Chinese general population.

In this cross-sectional study on the metabolic diseases (e.g. obesity) among Uygur Chinese in Hetian, Xinjiang, China,from January to February 2007, 2127 Uygur individuals were enrolled. The sample size for IR subjects [homeostasis model assessment for insulin resistance (HOMA-IR) ≥2.3 65%] was 669, whereas that for non-IR controls was 664 (HOMA-IR≤1.335%). STEAP4 gene was sequenced in 50 Uygur Chinese individuals with IR (HOMA-IR≥2.3). The representative variations were selected from the population based on a r(2) cutoff of 0.8 and a minor allele frequency of >5% for case-control study.

Totally 16 variations including 10 novel variations (no reported in dbSNP) were identified in 50 Uygur individuals with IR. 7414 G/A (rs8122)(P/Pc=0.004/0.012)and 224A/G (rs1981529, Gly75Asp)(P/Pc=0.015/0.045)variations were significantly correlated with IR phenotype in Uygur subjects. As shown by multiple linear regression analysis, the mean values of waist circumference (WC) (P/Pc=0.032/0.256), body mass index (BMI) (P/Pc=0.004/0.032), HOMA-IR (P/Pc=0.010/0.08), and fasting insulin (P/Pc=0.023/0.184) among A (protection) allele carriers of rs8122 and the mean values of WC (P/Pc=0.005/0.040) and BMI (P/Pc=0.002/0.016) among G (protection) allele carriers of rs1981529 gradually declined. Haplotype 1 (rs8122 G- rs1981529 A- rs34741656 G) was significantly associated with a higher prevalence of IR (Permutation P=0.021).

STEAP4 genetic variations are likely to be associated with obesity-related insulin resistance in Uygur Chinese general population.