Table 2—

Glycemic control measurements at baseline and last double-blind visit

VariableMetforminPlaceboDifference (metformin – placebo)
Baseline mean FPG (mmol/l)9.0 ± 2.710.7 ± 2.7
Last double-blind visit mean FPG (mmol/l)7.0 ± 2.211.5 ± 4.5
Adjusted mean* FPG change from baseline (mmol/l)−2.4 ± 0.51.2 ± 0.5−3.6 ± 0.8
 95% CI  −3.5 to −1.3  0.1 to  2.3   5.1 to −2.0
P  <0.001
Baseline mean HbA1c (%)8.2 ± 1.38.9 ± 1.4
Last double-blind visit mean HbA1c (%)7.2 ± 1.28.9 ± 1.6
Adjusted mean* HbA1c (%)7.5 ± 0.28.6 ± 0.2−1.2 ± 0.2
 95% CI  (7.2–7.8) (8.3–9.0)  (−1.6–−0.7)
P§  <0.001
  • Data are means ± SD unless otherwise indicated.

  • *

    * Mean adjusted for baseline FPG or for baseline HbA1c.

  • The P value is based on an ANCOVA, comparing metformin to placebo using baseline FPG as the covariate and treatment as the main effect.

  • Significance level P < 0.03355, where the testwise critical value was adjusted for an 8-week interim analysis of FPG, to preserve an overall α level of ≤0.05 using the O’Brien-Fleming method with an α of 0.025 at the interim analysis.

  • §

    § P value is based on an ANCOVA, comparing metformin to placebo using baseline HbA1c as the covariate and treatment as the main effect.