Table 1 .
Characteristics of included studies
| Study | Comparisons | Duration (weeks) | Study population/ethnicity | Country | Body weight groups included | Balanced male/female? | Mean age | Standardised diet/exercise | Background OAD |
|---|---|---|---|---|---|---|---|---|---|
| Apovian et al42 | EX/PLAC | 24 | MR | US | OW | >60% F | 54.8 | Y | MET and/or SU |
| Barnett et al43 | EX/IG | 16 | MR | Multinational | N/OW/OB | Y | 54.9 | N | MET or SU |
| Bergenstal et al44 | EX/BIAsp | 24 | MR | US | N/OW | Y | 52.6 | N | MET and SU |
| Bergenstal et al45 | EX LAR vs PIO EX LAR vs SITA |
26 | MR | Multinational | N/OW/OB | Y | 52.3 | N | MET |
| Buse et al46 | EX/PLAC | 30 | MR | US | OW/OB | 60% M | 55.3 | N | SU |
| Buse et al47 | IG+EX/ IG+PLAC | 30 | MR | Multinational | N/OW/OB | Y | 59.0 | N | MET or PIO |
| Davies et al48 | EX/IG | 26 | MR | GB | OW/OB | >60% M | 56.5 | N | Two or three OADS: MET, SU, or TZD |
| DeFronzo et al49 | EX/PLAC | 30 | MR | US | OW/OB | Y | 53.0 | N | MET |
| DeFronzo et al50 | EX vs ROSI | 20 | MR | US | OW/OB | Y | 56.0 | N | MET |
| Derosa et al51 | EX/GLIB | 52 | W | IT | OW/OB | Y | 56.5 | Y | MET |
| Derosa et al52 | EX/GLIM | 52 | CAUC | IT | OW/OB | Y | 55.5 | Y | MET |
| Diamant et al53 | EX LAR/IG | 26 | MR | Multinational | OW/OB | Y | 58.0 | N | MET |
| Gallwitz et al54 | EX/BIAsp | 26 | MR | GER | OW/OB | Not reported | 57.0 | N | MET |
| Gallwitz et al55 | EX/GLIM | Up to 4.5 years | MR | Multinational | OW/OB | Y | 56.0 | N | MET |
| Gao et al56 | EX/PLAC | 12 | C/I/K/T | Multinational | N/OW/OB | Y | 54.0 | N | MET and/or SU |
| Garber et al57 | LIR/GLIM | 52 | MR | US/MEX | N/OW/OB | Y | 53.0 | N | Nil—previous OAD withdrawn |
| Gill et al58 | EX/PLAC | 12 | MR | CAN/NL | OW/OB | Y | 55.6 | N | MET and/or TZD |
| Heine et al59 | EX/IG | 26 | MR | Multinational | OW/OB | Y | 58.9 | N | MET and SU |
| Kadowaki et al60 | EX/PLAC | 12 | JP | JP | N/OW/OB | >60% M | 60.3 | N | SU, with or without either BG or TZD |
| Kendall et al61 | EX/PLAC | 30 | MR | US | OW/OB | Y | 55.3 | Y | MET and SU |
| Kim et al62 | EX LAR/PLAC | 15 | MR | US | OW/OB | 60% M | 53.7 | Y | MET |
| Liutkus et al63 | EX/PLAC | 26 | MR | Multinational | OW/OB | Y | 54.7 | N | TZD with or without MET |
| Marre et al64 | LIR/PLAC/ROSI | 26 | MR | Multinational | N/OW/OB | Y | 56.0 | N | SU |
| Moretto et al65 | EX/PLAC | 24 | MR | Multinational | OW/OB | Y | 54.0 | Y | DRUG NAIVE |
| Nauck et al66 | EX/PIA | 52 | MR | Multinational | OW/OB | Y | 58.5 | N | SU and MET |
| Nauck et al67 | LIR/GLIM/PLAC | 26 | MR | Multinational | N/OW/OB | Y | 56.7 | N | MET |
| Pratley et al68 | LIR/SIT | 26 | MR | Multinational | N- OW-OB | Y | 55.3 | N | MET |
| Russell-Jones et al69 | LIR/IG/PLAC | 26 | MR | Multinational | N/OW/OB | Y | 57.5 | N | MET and SU |
| Russell-Jones et al70 | EX LAR/MET EX LAR/PIO EX LAR/SITA |
26 | MR | Multinational | N/OW/OB | Y | 54.0 | N | DRUG NAIVE |
| Yang et al71 | LIR/GLIM | 16 | C/K/I | Multinational | N/OW/OB | Y | 53.3 | N | MET |
| Zinman et al72 | EX/PLAC | 16 | MR | Multinational | OW/OB | Y | 56.1 | N | TZD with or without MET |
| Zinman et al73 | LIR/PLAC | 26 | MR | US/CAN | N/OW/OB | Y | 55.0 | N | MET and ROSI |
BG, Biguanide; BIAsp, biphasic insulin aspart; C, Chinese; CAN, Canada; CAUC, Caucasian; EX LAR, exenatide long-acting release; EX, exenatide; GB, Great Britain; GER, Germany; GLIB, glibenclamide; GLIM, glimepiride; I, Indian; IG, insulin glargine; IT, Italy; JP, Japan; JP, Japanese; K, Korean; LIR, liraglutide; MET, metformin; MEX, Mexico; MR, Multiracial; N, normal weight; NL, the Netherlands; OAD, oral antidiabetic drug; OB, obese; OW, overweight; PIO, pioglitazone; PLAC, placebo; ROSI, rosiglitazone; SITA, sitagliptin; T, Taiwanese; US, the USA; W, White.