[Study on relationship between endogenous androgens and insulin resistance at the different stages of postmenopause].

OBJECTIVE

To investigate the relationship between insulin resistance and endogenous androgens at early and late phase of postmenopause.

METHODS

A total of 105 women with early postmenopause ( ≤ 5 years since menopause) and 107 women with late postmenopause ( ≥ 10 years since menopause) were enrolled in this study.In the mean time, those women were classified into normal weight[body mass index (BMI), BMI <24 kg/m(2)] group and overweight (BMI ≥ 24 kg/m(2)) group.Sex hormone-binding globulin (SHBG), testosterone (T) , dehydroepiandrosterone-sulfate (DHEA-S) , fasting blood glucose(FBG), fasting insulin (FINS) levels were measured and then calculated free androgen index (FAI) and homeostatic model assessment of insulin resistance (HOMA-IR) . The relationship between sex hormones and insulin resistance was analyzed by partial correlation and multiple linear regression analyses.

RESULTS

Compared to early postmenopausal women, late postmenopausal women had higher FINS [(7.9 ± 6.6) mU/L versus (6.6 ± 4.0) mU/L] and HOMA-IR(2.1 ± 1.9 versus 1.7 ± 1.1), but they had lower DHEA-S[(0.9 ± 0.5) mg/L versus (1.1 ± 0.5) mg/L, all P < 0.05) ]. Both in early postmenopausal and late postmenopausal groups, overweight women had higher HOMA-IR (early group, 2.2 ± 1.0 versus 1.2 ± 0.9;late group, 2.8 ± 2.6 versus 1.6 ± 1.1) and FINS early group[(6.9 ± 2.9) mU/L versus (4.6 ± 2.0) mU/L];late group[(10.2 ± 9.3) mU/L versus (6.4 ± 3.6) mU/L] than those at women with normal weight group (all P < 0.05) .In early postmenopausal group, overweight women had lower SHBG[ (52 ± 37) nmol/L versus (71 ± 37) nmol/L] and higher FAI (2.5 ± 2.1) versus (1.3 ± 1.1) than those at normal weight women group (all P < 0.05) .In late postmenopausal group, overweight women had higher DHEA-S (1.0 ± 0.5) mg/L versus (0.8 ± 0.4) mg/L (P < 0.05) . The analyses suggested that in early postmenopausal group, SHBG was correlated negatively with FINS and HOMA-IR (β = -0.386, P < 0.05;β = -0.553, P < 0.05) , DHEA-S was correlated positively with FBG (β = 0.348, P < 0.05) in early postmenopausal group.FAI was correlated positively with FBG in late postmenopausal group (β = 0.505, P < 0.05) .

CONCLUSIONS

The increased androgenic activities are associated with insulin resistance after of menopause. These correlations are different at different stages of postmenopause, which SHBG levels correlate with high risk of insulin resistance and DHEA-S levels correlates with high blood glucose levels at early postmenopause and FAI correlates with high blood glucose levels at late postmenopause.