Table 4—

Adjusted* associations of coffee with incident type 2 diabetes by baseline glucose level, Rancho Bernardo Study, 1984–1987

Coffee exposureTotal nondiabeticNormal glucoseImpaired glucose
n910593317
Coffee status
    Past drinker/never drank13/18, 0.38 (0.17–0.87)4/3, 0.63 (0.12–3.21)9/15, 0.31 (0.11–0.87)
    Current drinker/never drank53/18, 0.36 (0.19–0.68)14/3, 0.40 (0.10–1.65)39/15, 0.36 (0.16–0.83)
Daily coffee consumption after age 45 years (cups)
    1–2/031/31, 0.66 (0.38–1.14)8/7, 0.64 (0.22–1.89)23/24, 0.71 (0.35–1.41)
    3–4/013/31, 0.53 (0.26–1.08)4/7, 0.54 (0.15–2.00)9/24, 0.55 (0.22–1.36)
    ≥5/09/31, 0.60 (0.26–1.40)2/7, 0.33 (0.06–1.80)7/24, 1.01 (0.33–3.13)
Cup-years (per 20)0.99 (0.93–1.05)1.01 (0.92–1.12)0.98 (0.90–1.06)
  • Data are n, OR (95% CI).

  • *

    * Models are adjusted for age, sex, exercise, BMI, smoking, daily alcohol intake, hypertension, and FPG assessed at baseline, 1984–1987.

  • Normal glucose defined as FPG <6.1 mmol/l and PCG <7.8 mmol/l or missing PCG. Impaired glucose defined as either impaired fasting glucose (6.1 mmol/l ≤ FPG < 7.0 mmol/l and PCG < 7.8 mmol/l) or impaired glucose tolerance (FPG < 6.1 mmol/l and 7.8 mmol/l ≤ PCG < 11.1 mmol/l).

  • Because of missing coffee drinking start date, cup-years were based on sample sizes of 815, 279, and 536 for the total nondiabetic sample, those with normal glucose at baseline, and those with impaired glucose at baseline, respectively.