Table 1. Characteristics of the included studies.
| Author, year | Interventions | Sample size | Mean Age (years) | Male (%) | Mean HbA1c (%) | Mean body weight, kg | Mean BMI (kg/m2) | Study duration (weeks) |
|---|---|---|---|---|---|---|---|---|
| Ba 2017[24] | Sita: 100mg | 249 | 57.5 | 47.0 | 8.6 | 68.4 | 25.4 | 24 |
| PLA | 249 | 56.5 | 53.0 | 8.5 | 68.9 | 25.3 | 24 | |
| Gantz 2017[25] | Omar: 25mg | 126 | 63 | 72.2 | 8.1 | 65 | 24.5 | 24 |
| PLA | 63 | 63 | 71.4 | 8.1 | 67 | 24.8 | 24 | |
| Yang 2015[26] | Vild: 50mg | 143 | 58.3 | 55.2 | 8.6 | 67.4 | 24.8 | 24 |
| PLA | 136 | 58.7 | 58.1 | 8.7 | 68.8 | 25.0 | 24 | |
| Hermansen 2007[27] | Sita: 100mg | 222 | 55.6 | 52.7 | 8.3 | 86.5 | 31.2 | 24 |
| PLA | 219 | 56.5 | 53.4 | 8.3 | 85.9 | 30.7 | 24 | |
| Barnett 2013[28] | Lina: 5mg | 95 | 75 | 72 | 7.8 | 86.3 | 29.6 | 24 |
| PLA | 43 | 75* | 62* | 7.7* | 86.4* | 29.8* | 24 | |
| Garber 2008[29] | Vild: 50mg | 132 | 58.6 | 78 | 8.5 | NA | 32.2 | 24 |
| Vild: 100mg | 132 | 58.2 | 79 | 8.6 | NA | 30.8 | 24 | |
| PLA | 144 | 57.9 | 84 | 8.5 | NA | 31.0 | 24 | |
| Pratley 2009[30] | Alog: 12.5mg | 203 | 56.5 | 54.7 | NA | NA | 30.2 | 26 |
| Alog: 25mg | 198 | 56.5 | 50.0 | NA | NA | 30.0 | 26 | |
| PLA | 99 | 57.1 | 51.5 | NA | NA | 30.0 | 26 | |
| Chacra 2009[31] | Saxa: 2.5mg | 248 | 55.4 | 45.6 | 8.4 | 75.2 | 29.1 | 24 |
| Saxa: 5mg | 253 | 54.9 | 43.5 | 8.5 | 76.2 | 29.2 | 24 | |
| PLA | 267 | 55.1 | 46.1 | 8.4 | 75.6 | 28.8 | 24 | |
| Yale 2017[32] | Cana: 100mg | 74 | 65.8 | 50.0 | 8.3 | 80.7 | NA | 52 |
| Cana: 300mg | 72 | 64.3 | 58.3 | 8.1 | 80.5 | NA | 52 | |
| PLA | 69 | 64.3 | 59.4 | 8.4 | 84.2 | NA | 52 | |
| Dungan 2016[33] | Dula: 1.5mg | 239 | 57.7 | 43.5 | 8.4 | 84.5 | 30.9 | 24 |
| PLA | 60 | 58.2 | 46.7 | 8.4 | 89.5 | 32.4 | 24 | |
| Forst 2015[34] | Vild: 50mg | 82 | 65.9 | 56.1 | 7.6 | 85.5 | 29.7 | 24 |
| NPH insulin | 79 | 67.6 | 60.8 | 7.7 | 89.9 | 31.4 | 24 | |
| Strojek 2014[35] | Dapa: 2.5mg | 154 | 59.9 | 50.0 | 8.1 | 81.9 | 30.0 | 48 |
| Dapa: 5mg | 142 | 60.2 | 50.0 | 8.1 | 81.0 | 29.8 | 48 | |
| Dapa: 10mg | 151 | 58.9 | 43.7 | 8.1 | 80.6 | 29.8 | 48 | |
| PLA | 145 | 60.3 | 49.0 | 8.2 | 80.9 | 29.7 | 48 | |
| Hsieh 2011[36] | Migi: 50mg | 52 | 58.4 | 44.2 | 8.1 | 67.2 | 25.3 | 24 |
| PLA | 53 | 59.0 | 34.0 | 8.1 | 69.2 | 26.1 | 24 | |
| Scheen 2009[37] | Piog: <45mg | 508 | 63.2 | 67.9 | 7.8 | NA | 29.7 | 30 |
| PLA | 493 | 62.9 | 70.6 | 7.7 | NA | 29.9 | 30 | |
| Marre 2009[38] | Lira: 0.6mg | 233 | 55.7 | 54 | 8.4 | 82.6 | 30.0 | 26 |
| Lira: 1,2mg | 228 | 57.7 | 45 | 8.5 | 80.0 | 29.8 | 26 | |
| Lira: 1.8mg | 234 | 55.6 | 53 | 8.5 | 83.0 | 30.0 | 26 | |
| Rosi: 4mg | 232 | 56.0 | 47 | 8.4 | 80.6 | 29.4 | 26 | |
| PLA | 114 | 54.7 | 47 | 8.4 | 81.9 | 30.3 | 26 | |
| Davidson 2007[39] | Rosi: 8mg | 117 | 52 | 54.7 | 9.2 | 86.3 | 31.3 | 24 |
| PLA | 116 | 53 | 51.7 | 9.4 | 88.3 | 31.9 | 24 | |
| Buse 2004[40] | Exen: 5μg | 125 | 55 | 59.2 | 8.5 | 95 | 33 | 30 |
| Exen: 10μg | 129 | 56 | 57.4 | 8.6 | 95 | 33 | 30 | |
| PLA | 123 | 55 | 62.6 | 8.7 | 99 | 34 | 30 | |
| Araki 2015[41] | Empa: 10mg | 136 | 61.3 | 72.8 | 8.0 | 65.8 | 24.6 | 52 |
| Empa: 25mg | 137 | 61.8 | 70.1 | 8.1 | 67.0 | 25.2 | 52 | |
| Met: <2550mg | 63 | 60.0 | 74.6 | 7.9 | 68.2 | 25.2 | 52 | |
| Kobayashi 2014[42] | Sita: 50mg | 59 | 64.3 | 61.0 | 7.7 | 62.6 | 23.8 | 24 |
| Migi: 50mg | 55 | 64.0 | 61.8 | 7.6 | 65.0 | 24.7 | 24 | |
| Wolffenbuttel 2000[43] | Rosi: 2mg | 199 | 61.0 | 62.8 | 9.2 | NA | 28.0 | 26 |
| Rosi: 4mg | 183 | 60.6 | 55.2 | 9.2 | NA | 28.3 | 26 | |
| PLA | 192 | 61.9 | 57.3 | 9.2 | NA | 28.1 | 26 | |
| Kaku 2010[44] | Lira: 0.6mg | 88 | 59.1 | 60 | 8.6 | 66.1 | 25.3 | 24 |
| Lira: 0.9mg | 88 | 61.3 | 67 | 8.2 | 64.5 | 24.4 | 24 | |
| PLA | 88 | 58.6 | 65 | 8.4 | 66.7 | 24.9 | 24 | |
| Zhu 2003[45] | Rosi: 4mg | 215 | 59.0 | 41 | 9.8 | NA | 24.8 | 24 |
| Rosi: 8mg | 210 | 58.9 | 48 | 9.9 | NA | 24.9 | 24 | |
| PLA | 105 | 58.8 | 46 | 9.8 | NA | 25.1 | 24 | |
| Seufert 2008[46] | Piog: <45mg | 319 | 60 | 53.6 | 8.8 | NA | 30.2 | 104 |
| Met: <2550mg | 320 | 60 | 54.7 | 8.8 | NA | 30.0 | 104 | |
| Bachmann 2003[47] | Acar: 100mg | 164 | 63.8 | 52.4 | 9.4 | 80.7 | 29.0 | 78 |
| PLA | 166 | 63.3 | 56.6 | 9.4 | 81.6 | 29.0 | 78 |
* Data refer to the overall study population.
HbA1c, glycated hemoglobin; BMI, body mass index; Alog, alogliptin; Saxa: saxagliptin; Vild, vildagliptin; Lina, linagliptin; Sita, sitagliptin; Omar, omarigliptin; Lira, liraglutide; Exen, exenatide; Dula, Dulaglutide; Acar, acarbose; Migi, miglitol; Piog, pioglitazone; Rosi, rosiglitazone; Met, metformin; PLA, placebo; NA, not applicable.