The mediation role of SOCS3 methylation in the effect of serum testosterone on type 2 diabetes.

ABSTRACT

BACKGROUND: Previous studies reported that testosterone and DNA methylation of suppressor of cytokine signaling-3 (SOCS3) were associated with type 2 diabetes (T2D). Testosterone affects SOCS3 gene expression. Therefore, we aimed to investigate how the SOCS3 methylation mediates the relationship between testosterone and T2D among Chinese rural adults. METHODS: A case-control study comprised 365 T2D patients and 651 controls was conducted. Liquid chromatography-tandem mass spectrometry and MethylTarget were used to determine the levels of serum testosterone and DNA methylation of SOCS3 gene, respectively. The odds ratio (OR) of testosterone or SOCS3 methylation for T2D was calculated using logistic regression models, and ß value of testosterone for SOCS3 methylation was evaluated by linear regression models. Furthermore, through mediation analysis the mediating effect of SOCS3 methylation on the association of testosterone with T2D was estimated. RESULTS: After adjusting for multiple variables, the protective effect of testosterone on T2D was found in men (OR = 0.61, 95% confidence interval [CI] 0.47-0.80), and the methylation of Chr1776356190 or Chr1776356199 was negatively related to T2D in both men and women. Moreover, testosterone was positively associated with Chr1776356190 methylation in men and Chr1776356199 methylation in women (both P < .05). The mediation analysis showed that the Chr1776356190 methylation partly mediated effect of testosterone on T2D in men was approximately 8.2%. CONCLUSIONS: High levels of serum testosterone in men and Chr1776356190 and Chr1776356199 (SOCS3) methylation were related to a lower prevalent T2D. In addition, Chr1776356190 methylation partially mediated the effect of testosterone on T2D in Chinese rural men.