The occurrence of hypogonadotropic hypogonadism in Chinese men with type 2 diabetes.

CONTEXT: The previous studies showed that hypogonadotropic hypogonadism (HH) occurred commonly in men with type 2 diabetes. However, since all the cohorts tested were from American and European studies, the occurrence of HH/nongonadal illness (NGI) in Chinese populations is unclear.

OBJECTIVE

The study aimed to explore the occurrence of HH/NGI in Chinese men with type 2 diabetes. Furthermore, the correlative factors and predictors of hypogonadism were investigated.

DESIGN

We conducted a cross-sectional study of 637 Chinese men with type 2 diabetes aged 20-75 years in our clinic. The prevalence of HH/NGI was investigated by measuring serum total testosterone (TT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the enrolled subjects. Free testosterone (FT) was calculated by using SHBG and TT levels and hypogonadism was defined as TT lower than 10.4 nmol/L and calculated FT (cFT) lower than 0.225 nmol/L. The LH cut-off value for defining HH/NGI was 9.4 mIU/ml.

RESULTS

The results suggested that 31.9% of male Chinese type 2 diabetes patients had hypogonadism and 26.5% of subjects in our cohort were determined as HH/NGI. The occurrence of hypogonadism was markedly correlated with body mass index (BMI). There was a significant association between TT, cFT and SHBG levels with BMI. TT levels are inversely correlated with BMI and homeostasis model assessment-estimated insulin resistance (HOMA-IR) while positively related with SHBG. The cFT levels were inversely correlated with age, LH, FSH, BMI and HOMA-IR. Multiple regression analysis suggested that SHBG, BMI and HOMA-IR were significant predictors of TT and cFT.

CONCLUSION

Our present study offered the first evidence that the occurrence of HH/NGI in Chinese male type 2 diabetes was 26.5%. TT and cFT were significantly correlated with BMI, SHBG and HOMA-IR in Chinese men with type 2 diabetes.