Table 2: Twelve studies selected as sitagliptin as dual therapy group (group 2)

Study

Design

Dose

Follow-up

N

Baseline HbA1c % (SE %)

Change of HbA1c % (SE %)

Charbonnel 2006 [26]

R, SB1

S 100 mg QD4 + M ≥ 1500 mg/day2

24wk

453

7.96 (0.81)

-0.67 (0.051)

Scott 2008 [27]

R, DB

S 100 mg QD + M ≥ 1500 mg/day

18wk

91

7.75 (0.99)

-0.73 (0.068)

Nauck 2007 [28]

R, DB

S 100 mg QD + M ≥ 1500 mg/day

52wk

382

7.48 (0.76)

-0.67 (0.041)

Arechavaleta 2011 [29]

R, DB

S 100 mg QD + M ≥ 1500 mg/day

30wk

443

7.48 (0.68)

-0.47 (0.041)

Aschner 2012 [14]

R, O

S 100 mg QD + M ≥ 1500 mg/day

24wk

253

8.5 (1.1)

-1.13 (0.06)

Pratley 2010 [30]

R, O

S 100 mg QD + M ≥ 1500 mg/day

26wk

219

8.5 (0.7)

-0.90 (0.066)

Raz 20083 [31]

R, DB

S 100 mg QD + M ≥ 1500 mg/day

18wk

95

9.3 (0.9)

-1.00 (0.102)

Reasner 2011 [32]

R, DB

S 50 mg BID + M 500 mg BID

18wk

559

9.9 (1.8)

-2.40 (0.076)

Scheen 2010 [33]

R, DB

S 100 mg QD + M 1500-3000 mg/day

18wk

343

7.69 (0.9)

-0.62 (0.038)

Wainstein 2012 [34]

R, DB

S 50 mg BID + M 500 mg BID

32wk

253

8.9 (1.3)

-1.90 (0.076)

Rigby 2010 [35]

R, O

S 100 mg QD + M ≥ 1500 mg/day

16wk

55

8.17 (0.91)

-0.40 (0.130)

Bergenstal 2010 [36]

R, DB

S 100 mg QD + M ≥ 1500 mg/day

26wk

166

8.5 (1.2)

-0.90 (0.102)

 

1SB: single-blinded; O: open-labeled

2S: sitagliptin; M: metformin

3Studies have multiple follow-up visits, and we used the visit closest to 24 weeks.

4QD: once a day; BID: twice a day