TABLE 2

RRs of self-reported type 2 diabetes by randomized folic acid and B vitamins intervention in the WAFACS

Number of events/number of participants (%)
RR (95% CI)
Active (n = 2,132)Placebo (n = 2,120)Age-adjusted model*Multivariate-adjusted model
Follow-up interval (years)
    1–259 (2.77)72 (3.40)0.81 (0.58–1.14)0.79 (0.55–1.12)
    3–5101 (4.74)101 (4.76)0.99 (0.75–1.31)0.97 (0.73–1.28)
    0–5160 (7.50)173 (8.16)0.92 (0.74–1.14)0.89 (0.72–1.11)
    ≥585 (3.99)86 (4.06)0.98 (0.72–1.32)0.95 (0.70–1.30)
    Total245 (11.5)259 (12.2)0.94 (0.79–1.11)0.91 (0.76–1.09)
Sensitivity analyses
    Excluding first 2 years186 (8.72)187 (8.82)0.98 (0.80–1.21)0.97 (0.78–1.19)
Compliance analyses
    Taking two-thirds or more of folic acid/B vitamins/placebo pills223 (10.5)238 (11.2)0.92 (0.76–1.10)0.87 (0.72–1.05)
  • *Adjusted for age and other randomized assignments (vitamins C and E and β-carotene).

  • †Additionally adjusted for baseline variables, including BMI, smoking status, postmenopausal hormone use, multivitamin use, alcohol intake, coffee intake, physical activity, and family history of diabetes.