Table 1—

Fasting efficacy end points

ParameterPlaceboSitagliptin 100 mg q.d.Metformin 500 mg b.i.d.Metformin 1,000 mg b.i.d.Sitagliptin 50 mg + metformin 500 mg b.i.d.Sitagliptin 50 mg + metformin 1,000 mg b.i.d.
A1C (%)
    n165175178177183178
    Baseline8.68 ± 1.008.87 ± 0.998.90 ± 1.008.68 ± 0.918.79 ± 1.008.76 ± 0.95
    Week 248.88 ± 1.478.18 ± 1.458.04 ± 1.367.58 ± 1.277.37 ± 1.206.87 ± 1.09
    Change from baseline0.17 (0.00–0.33)−0.66 (−0.83 to −0.50)−0.82 (−0.98 to −0.66)−1.13 (−1.29 to −0.97)−1.40 (−1.56 to −1.24)−1.90 (−2.06 to −1.74)
    Change from placebo−0.83 (−1.06 to −0.60)*−0.99 (−1.22 to −0.75)*−1.30 (−1.53 to −1.06)*−1.57 (−1.80 to −1.34)*−2.07 (−2.30 to −1.84)*
FPG (mg/dl)
    n169178179179183180
    Baseline196.3 ± 47.4201.4 ± 49.4205.2 ± 50.6197.0 ± 46.8203.9 ± 51.7196.7 ± 48.2
    Week 24203.6 ± 61.0183.4 ± 54.8175.8 ± 56.0169.0 ± 64.9155.1 ± 47.6134.2 ± 36.1
    Change from baseline5.8 (−1.0 to 12.7)−17.5 (−24.1 to −10.8)−27.3 (−34.0 to −20.7)−29.3 (−35.9 to −22.6)−47.1 (−53.7 to −40.6)−63.9 (−70.5 to −57.3)
    Change from placebo−23.3 (−32.8 to −13.8)*−33.1 (−42.7 to −23.6)*−35.1 (−44.6 to −25.6)*−52.9 (−62.4 to −43.5)*−69.7 (−79.2 to −60.2)*
Fasting proinsulin (pmol/l)
    n91114130138153161
    Baseline33.3 ± 32.830.6 ± 25.536.1 ± 30.338.5 ± 31.336.9 ± 34.736.2 ± 30.6
    Week 2433.7 ± 30.731.5 ± 30.230.4 ± 25.827.7 ± 29.130.2 ± 35.020.4 ± 19.1
    Change from baseline−0.5 (−4.7 to 3.7)−1.0 (−4.8 to 2.8)−5.5 (−9.1 to −2.0)−9.7 (−13.1 to −6.3)−6.2 (−9.5 to −3.0)−15.5 (−18.6 to −12.3)
    Change from placebo−0.5 (−6.1 to 5.1)−5.0 (−10.5 to 0.4)−9.2 (−14.6 to −3.8)*−5.7 (−11.0 to −0.4)§−14.9 (−20.2 to −9.7)*
Proinsulin-to-insulin ratio
    n91114129137152157
    Baseline0.42 ± 0.220.44 ± 0.210.48 ± 0.300.48 ± 0.250.51 ± 0.310.49 ± 0.35
    Week 240.45 ± 0.390.38 ± 0.200.39 ± 0.260.35 ± 0.180.35 ± 0.240.28 ± 0.17
    Change from baseline−0.01 (−0.05 to 0.04)−0.08 (−0.12 to −0.04)−0.09 (−0.12 to −0.05)−0.12 (−0.16 to −0.09)−0.14 (−0.17 to −0.11)−0.20 (−0.23 to −0.17)
    Change from placebo−0.08 (−0.13 to −0.01)−0.08 (−0.14 to −0.03)−0.12 (−0.17 to −0.06)*−0.14 (−0.19 to −0.08)*−0.20 (−0.25 to −0.15)*
HOMA-β
    n139147159154166160
    Baseline40.9 ± 34.137.9 ± 32.243.1 ± 38.344.8 ± 37.741.8 ± 37.641.4 ± 33.4
    Week 2444.7 ± 49.848.7 ± 43.554.2 ± 45.159.1 ± 50.672.8 ± 61.174.4 ± 56.8
    Change from baseline3.7 (−2.5 to 9.9)10.8 (4.8 to 16.9)11.1 (5.3 to 16.9)14.3 (8.4 to 20.3)31.0 (25.3 to 36.7)33.0 (27.2 to 38.8)
    Change from placebo7.1 (−1.6 to 15.8)7.3 (−1.2 to 15.9)10.6 (2.0 to 19.2)27.3 (18.9 to 35.7)*29.3 (20.8 to 37.8)*
HOMA-IR
    n139147159154166160
    Baseline6.0 ± 4.06.0 ± 4.56.6 ± 5.06.9 ± 4.87.0 ± 6.66.6 ± 5.6
    Week 246.6 ± 4.76.1 ± 5.05.9 ± 4.75.4 ± 4.36.0 ± 5.64.2 ± 3.3
    Change from baseline0.3 (−0.3 to 1.0)−0.2 (−0.8 to 0.4)−0.7 (−1.3 to −0.1)−1.3 (−1.9 to −0.7)−0.8 (−1.4 to −0.2)−2.4 (−2.9 to −1.8)
    Change from placebo−0.5 (−1.4 to 0.4)−1.1 (−1.9 to −0.2)−1.6 (−2.5 to −0.8)*−1.1 (−2.0 to −0.3)−2.7 (−3.5 to −1.8)*
  • Data are means ± SD for baseline and week 24 data and least-squares mean change (95% CI) for change from baseline or placebo.

  • * P ≤ 0.001 for the between-group difference relative to placebo.

  • P ≤ 0.001 for the between-group difference comparing coadministration and both of its respective components.

  • P ≤ 0.05 for the between-group difference relative to placebo.

  • § P < 0.05 for the between-group difference comparing coadministration and sitagliptin 100 mg q.d.

  • P ≤ 0.05 for the between-group difference comparing coadministration and both of its respective components.