Coffee and Caffeine Consumption in Relation to Sex Hormone–Binding Globulin and Risk of Type 2 Diabetes in Postmenopausal Women

TABLE 5

Caffeinated coffee consumption in relation to plasma SHBG levels and type 2 diabetes stratified by SHBG SNPs

SHBG genotype
rs6259 rs6257
GG (wild type) AG or AA (variant) CT or CC (variant) TT (wild type)
Plasma SHBG levels (nmol/l)* n n n n
    Caffeinated coffee intake
        Low (<2 cups per day) 277 23.2 (16.6–32.5) 70 23.3 (16.4–32.9) 69 20.3 (14.2–29.0) 285 23.2 (16.6–32.4)
        High (≥2 cups per day) 246 24.4 (17.4–34.3) 76 27.8 (19.4–39.7) 72 21.6 (15.2–30.8) 244 25.2 (17.9–35.4)
P for interaction 0.18 0.84
ORs (Case subjects/control subjects) (Case subjects/control subjects) (Case subjects/control subjects) (Case subjects/control subjects)
    Caffeinated coffee intake
        Low (<2 cups/day) 152/125 1.00 (reference) 40/30 0.90 (0.40–2.00) 42/27 1.00 (reference) 149/136 0.41 (0.19–0.88)
        High (≥2 cups/day) 122/124 0.70 (0.42–1.16) 26/50 0.54 (0.26–1.11) 34/38 0.40 (0.16–1.02) 109/135 0.38 (0.18–0.83)
P for interaction 0.79 0.13
  • Data are OR (95% CI) and n.

  • *The multivariate-adjusted geometric mean SHBG levels with 95% CIs for combinations of SHBG genotypes and caffeinated coffee intake levels (≥2 vs. <2 cups/day) adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI.

  • †Wald tests were used to test for statistical interaction by entering product terms into the regression models.

  • ‡The multivariate-adjusted ORs and 95% CIs of type 2 diabetes risk for combinations of SHBG genotypes and caffeinated coffee intake levels (≥2 vs. <2 cups/day) adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI.

This Article

  1. Diabetes vol. 60 no. 1 269-275