TABLE 2

Effect of current mean changes in time dependent covariates over time on the risk (hazard) of diabetes onset

Placebo group
Metformin group
HR95% CIPR2 (%)HR95% CIPR2 (%)
Univariate time-dependent covariate (unit)*
    Weight (kg)1.1081.080–1.137<0.00015.81.1131.072–1.155<0.00013.0
    Change in weight (%)1.0991.074–1.125<0.00015.81.0931.056–1.130<0.00012.5
    Waist (cm)1.0661.031–1.1020.00011.41.0330.994–1.0740.09520.3
    BMI (kg/m2)1.3481.249–1.454<0.00015.51.3311.203–1.474<0.00012.9
    Fasting insulin (pmol/l)1.0041.003–1.006<0.00012.41.0061.003–1.008<0.00012.0
    IGR (10 pmol/mmol)0.9910.985–0.9980.00900.60.9120.878–0.948<0.00012.1
    Proinsulin (pmol/l)1.0381.029–1.048<0.00016.21.0441.026–1.062<0.00012.3
    Fasting glucose (mmol/l)2.5002.256–2.771<0.000125.32.6952.310–3.145<0.000114.3
Multivariate time-dependent covariate (unit)
    Weight (kg)1.0991.068–1.132<0.00013.901.0871.045–1.131<0.00011.66
    Fasting insulin (pmol/l)1.0021.000–1.0040.12760.221.0031.001–1.0060.01240.61
    IGR (10 pmol/mmol)0.9910.985–0.9980.01380.580.9070.873–0.941<0.00012.55
  • *

    * Univariate models are adjusted for age, sex, ethnicity, fasting glucose, 2-h glucose, A1C, and the baseline value of the covariate (except for percent change in weight). The effects of recreational activity, leisure activity, and percent calories from fat over time were not significant at P ≤ 0.01 in either group.

  • Multivariate models are also adjusted for age, sex, and ethnicity; for baseline weight, recreational activity, percent calories from fat, and proinsulin levels; and for baseline and on-study levels of leisure activity. None of these effects were nominally significant at P ≤ 0.01 in either group.