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

TABLE 4

ORs for type 2 diabetes according to caffeinated coffee, decaffeinated coffee, tea, and caffeine consumption

0 cups/day ≤1 cups/day 2–3 cups/day ≥4 cups/day P for trend*
Caffeinated coffee (case subjects/control subjects) 99/86 103/84 105/107 49/73
    Median (cups/day) 0 1.0 2.5 4.5
    Match-adjusted model 1.00 1.04 (0.68–1.60) 0.82 (0.55–1.23) 0.55 (0.34–0.90) 0.008
    Categorical model 1.00 0.95 (0.52–1.74) 0.94 (0.53–1.67) 0.47 (0.23–0.94) 0.047
    Categorical model + SHBG§ 1.00 0.92 (0.46–1.84) 0.96 (0.48–1.94) 0.71 (0.31–1.61) 0.47
    Spline model 1.00 1.11 (0.63–1.97) 0.92 (0.55–1.54) 0.61 (0.34–1.11)
    Spline model + SHBG 1.00 0.87 (0.45–1.68) 0.86 (0.47–1.58) 0.80 (0.39–1.65)
Decaffeinated coffee (case subjects/control subjects) 211/190 94/94 37/47 8/15
    Median (cups/day) 0 0.4 2.5 4.5
    Match-adjusted model 1.00 0.87 (0.60–1.26) 0.63 (0.38–1.03) 0.49 (0.20–1.20) 0.03
    Categorical model 1.00 1.16 (0.70–1.95) 0.77 (0.38–1.55) 0.72 (0.19–2.69) 0.39
    Categorical model + SHBG§ 1.00 1.03 (0.56–1.90) 1.11 (0.46–2.71) 1.33 (0.27–6.49) 0.71
    Spline model 1.00 1.30 (0.90–1.88) 0.61 (0.33–1.14) 0.47 (0.17–1.29)
    Spline model + SHBG 1.00 1.31 (0.84–2.03) 0.91 (0.42–2.00) 0.92 (0.26–3.27)
Tea (case subjects/control subjects) 114/128 180/171 37/39 18/10
    Median (cups/day) 0 0.4 2.5 4.5
    Match-adjusted model 1.00 1.21 (0.87–1.69) 1.06 (0.64–1.74) 2.03 (0.91–4.54) 0.23
    Categorical model 1.00 1.12 (0.70–1.77) 1.22 (0.59–2.50) 1.53 (0.43–5.47) 0.46
    Categorical model + SHBG§ 1.00 0.97 (0.55–1.72) 1.14 (0.48–2.72) 1.74 (0.44–6.93) 0.42
    Spline model 1.00 1.39 (0.99–1.93) 1.52 (0.83–2.77) 1.32 (0.51–3.38)
    Spline model + SHBG 1.00 1.37 (0.93–2.03) 1.37 (0.67–2.78) 1.57 (0.54–4.58)
Caffeine category (mg/day) ≤50 51–250 251–500 >500
Caffeine intake (mg/day), median 13 140 366 656
    (case subjects/control subjects) 67/64 109/100 118/112 49/74
    Match-adjusted model 1.00 1.01 (0.65–1.56) 0.99 (0.63–1.54) 0.62 (0.37–1.04) 0.06
    Categorical model 1.00 1.00 (0.56–1.82) 1.26 (0.68–2.32) 0.56 (0.27–1.15) 0.18
    Categorical model + SHBG§ 1.00 0.94 (0.47–1.88) 1.44 (0.68–3.04) 0.89 (0.38–2.10) 0.91
    Spline model 1.00 1.56 (0.80–3.04) 1.56 (0.81–3.01) 0.92 (0.48–1.76)
    Spline model + SHBG 1.00 1.53 (0.71–3.30) 1.70 (0.79–3.62) 1.32 (0.61–2.82)
  • Data are OR (95% CI) unless otherwise indicated.

  • *P for trend values are based on median levels in categories.

  • †Match-adjusted model: stratified on matched pairs using conditional logistic regression models.

  • ‡Categorical model: further adjusted for smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI.

  • §Categorical model + SHBG: further adjusted for plasma SHBG.

  • ‖Spline model: ORs comparing odds at category medians from quadratic logistic spline models with one knot at the middle category boundaries adjusted for covariates used in categorical model.

  • ¶Spline model + plasma SHBG: further adjusted for plasma SHBG.

This Article

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