Low sex hormone-binding globulin (SHBG) is a consistent risk factor for type 2 diabetes, particularly in women. Coffee consumption has been associated with a lower risk of type 2 diabetes but its effects on SHBG are less known.
DESIGN AND METHODS:
This was a cross-sectional study of 2,377 non-diabetic pre- and post-menopausal women from the E3N cohort study whose baseline SHBG was measured. Information on diet (including coffee and caffeine consumption), lifestyle, and medical conditions was collected through questionnaires. The relationship between coffee and caffeine consumption and SHBG was modeled, with adjustment for covariates and stratification by body mass index (BMI) categories (< or ≥25 kg/m2 ) and menopausal status.
The mean age was 57.3 ± 6.4 years and 61% of the 2,453 women were postmenopausal. High coffee (≥3 cups/day) and caffeine (≥265 mg/day) intakes were associated with a reduced risk of being in the 1st quartile of the SHBG level distribution (<46.3 nmol∙L-1 ) in a multivariate adjusted model (OR: 0.69 [95% CI 0.52-0.92] and OR: 0.68 [95% CI 0.50-0.94] respectively). No association was found between tea consumption and SHBG levels. In multivariate models stratified on BMI categories and menopausal status, associations were restricted to women with a BMI ≥25 kg/m2 or being postmenopausal. The association with SHBG was consistently noted with both consumption of caffeinated coffee and caffeine, but not for decaffeinated coffee.
High coffee and caffeine consumptions are associated with a reduced risk of low SHBG, an established risk marker for T2DM, which might contribute to the protective effects of coffee for type 2 diabetes.