Table 1

Studies included in the analysis

Study arms Author, year and reference	Number of patients	Design	Type of DPP-4 inhibitor and FU (weeks)	Comparator	Add-on to	Baseline A1c (%)	Δ* A1c (%)	Age years	Analysis	FG mg/dL
Ristic, 2005¹	60	R, DB, P	Vilda 12	Placebo	None	7.64	−0.53	56	ITT	166
Pi-Sunyer, 2007²	79	R, DB, P	Vilda 24	Placebo	naïve	8.4	−0.7	50	ITT	196
Scheweizer, 2007³	511	R, DB, P	Vilda 52	Metformin	naïve	8.7	−1.1	52.8	ITT	189
Dejager, 2007⁴	90	R, DB, P	Vilda 24	Placebo	naïve	8.6	−0.8	52.8	ITT	182
Rosenstock, 2007⁵	150	R, DB, P	Vilda 24	Pioglitazone	naïve	8.6	−1.1	51.4	ITT	191
Garber, 2007⁶	136	R, DB, P	Vilda 24	Placebo	Pioglitazone	8.7	−1.2	54	ITT	180
Rosenstock, 2007⁷	459	R, DB, P	Vilda 24	Rosiglitazone	Naive	8.7	−1.1	54.5	ITT	185
Bosi, 2007⁸	143	R, DB, P	Vilda 24	Placebo	Metformin	8.4	−0.9	53.9	ITT	178
Garber, 2008⁹	132	R, DB, P	Vilda 24	Placebo	Glimepiride	8.6	−0.63	58.2	ITT	189
Bolli, 2008¹⁰	264	R, DB, P	Vilda 24	Pioglitazone	Metformin	8.4	−0.88	56.3	PP	196
Pan, 2008¹¹	389	R, DB, P	Vilda 24	Acarbose	Naive	8.6	−1.4	51.8	ITT	180
Ferrannini, 2009¹²	1118	R, DB, P	Vilda 52	Glimepiride	Metformin	7.3	−0.44	57.5	PP	165
Goodman, 2009¹³	119	R, DB, P	Vilda 24	Placebo	Metformin	8.5	−0.66	54.7	ITT	194
Bosi, 2009¹⁴	287	R, DB, P	Vilda 24	Metformin	Naive	8.7	−1.1	53.5	ITT	186
Scheweizer, 2009¹⁵	159	R, DB, P	Vilda 24	Metformin	Naive	7.8	−0.64	71.6	ITT	166
Kikuchi, 2009¹⁶	76	R, DB, P	Vilda 12	Placebo	Naive	7.4	−0.92	58.8	FAS	161
Foley, 2009¹⁷	409	R, DB, P	Vilda 104*	Gliclazide	None	8.5	−0.9	55.2	PP	194
Blonde, 2009¹⁸	1653	R, OL, P	Vilda 12	Thiazol	Metformin	7.99	−0.68	55.3	ITT	168
Filozov, 2010¹⁹	407	R, DB, P	Vilda 52	Gliclazide	Metformin	8.5	−0.81	59.2	PP	194
Derosa, 2010²⁰	155	R, DB, P	Vilda 52	None	Pio/Glimep	8.05	−1.2	58.5	ITT	140
Matthews, 2010²¹	1051	R, DB, P	Vilda 104*	Glimepiride	Metformin	7.3	−0.25	57.5	PP	166
Iawamoto, 2010²²	188	R, DB, P	Vilda 12	Voglibose	None	7.6	−0.95	60.3	FAS	160
Kikuchi, 2010²³	102	R, DB, P	Vilda 12	Placebo	Glimepiride	7.9	−1.0	59.2	FAS	164
Pan, 2012²⁴	146	R, DB, P	Vilda 24	Placebo	Metformin	8.09	−1.05	54.2	FAS	158
Strain, 2013²⁵	137	R, DB, P	Vilda 24	Placebo	Met+Su	7.9	−0.90	75.1	ITT	178
Lukashevic, 2013²⁶	158	R, DB, P	Vilda 24	Placebo	Met+Su	8.75	−1.01	53.5	FAS	167
Charbonnel, 2006²⁷	453	R, DB, P	Sita 24	Placebo	Metformin	7.9	−0.67	54	ATP	169
Raz, 2006²⁸	193	R, DB, P	Sita 18	Placebo	None	8.04	−0.48	54.5	ATP	180
Rosenstock, 2006²⁹	163	R, DB, P	Sita 24	Placebo	Pioglitazone	8.1	−0.85	55.6	ATP	168
Aschner, 2006³⁰	229	R, DB, P	Sita 24	Placebo	None	8.01	−0.61	53.4	ATP	144
Hermansen, 2007³¹	218	R, DB, P	Sita 24	Placebo	Met±Su	8.34	−0.45	55.6	ATP	181
Goldstein, 2007³²	175	R, DB, P	Sita 24	Placebo	None	8.87	−0.66	53.3	ATP	201
Hanefeld, 2007³³	106	R, DB, P	Sita 12	Placebo	None	7.6	−0.44	56	ATP	177
Nauck, 2007³⁴	382	R, DB, P	Sita 52	Glipizide	Metformin	7.48	−0.67	56.8	PP	166
Scott, 2007³⁵	121	R, DB, P	Sita 12	Placebo	None	7.8	−0.54	55.1	ATP	169
Scott, 2008³⁶	91	R, DB, P	Sita 12	Placebo	Metformin	7.75	−0.73	55.2	ATP	157
Raz, 2008³⁷	95	R, DB, P	Sita 30	Placebo	Metformin	9.3	−1.0	53.6	FAS	202
Nonaka, 2008³⁸	75	R, DB, P	Sita 12	Placebo	None	7.5	−0.65	55.6	FAS	163
Mohan, 2009³⁹	339	R, DB, P	Sita 18	Placebo	None	8.7	−0.7	50.9	FAS	189
Bergenstal, 2010⁴⁰	166	R, DB, P	Sita 26	Exen/Pio	Metformin	8.5	−0.9	52	ITT	164
Pratley, 2010⁴¹	219	R, OL, P	Sita 26	Liraglutide	Metformin	8.5	−0.9	55	FAS	180
Derosa, 2010⁴²	75	R, DB, P	Sita 52	Metformin	Pioglitazone	8.5	−1.4	57	ITT	143
Rigby, 2010⁴³	56	R, OL, P	Sita 16	Col/Rosi	Metformin	8.17	−0.4	54.8	FAS	181
Aschner, 2010⁴⁴	455	R, DB, P	Sita 24	Metformin	Naive	7.2	−0.43	56.3	PP	142
Scheen, 2010⁴⁵	334	R, DB, P	Sita 18	Saxagliptin	Metformin	7.7	−0.62	58.1	PP	160
Seck, 2010⁴⁶	248	R, DB, P	Sita 104*	Glipizide	Metformin	7.3	−0.8	57.8	PP	151
Arechavaleta, 2011⁴⁷	433	R, DB, P	Sita 30	Glimepiride	Metformin	7.5	−0.47	56.3	PP	144
Yang, 2012⁴⁸	192	R, DB, P	Sita 24	Placebo	Metformin	8.5	−0.9	54.1	FAS	173
Aschner, 2012⁴⁹	253	R, OL, P	Sita 24	Glargine	Metformin	8.5	−1.13	53.3	ITT	171
De Rosa, 2012⁵⁰	87	R, DB, P	Sita 52	Placebo	Metformin	8.0	−1.3	55.7	ITT	143
Bergenstal, 2012⁵¹	177	R, DB, P	Sita 24	Placebo	Metformin	7.94	−0.89	55.5	ITT	172
Russell-Jones, 2012⁵²	163	R, OL, P	Sita 26	Naive/Pio/Met	Exenatide	8.5	−1.15	54	ITT	180
Takihata, 2013⁵³	58	R, OL, P	Sita 24	Pioglitazone	Met±Su	7.5	−0.86	60.3	ITT	144
Fonseca, 2013⁵⁴	157	R, DB, P	Sita 26	Placebo	Met+Pio	8.8	−1.1	55.7	ITT	180
Philis-Tsimakis, 2013⁵⁵	222	R, DB, P	Sita 26	Degludec	Met/Su	8.27	−0.71	54.9	FAS	169
Liu, 2013⁵⁶	60	R, OP, P	Sita 24	Pioglitazone	Met+Su	8.27	−0.71	60	ITT	167
Dobs, 2013⁵⁷	170	R, DB, P	Sita 54	Placebo	Met+Rosi	8.8	−1.1	54.4	ITT	182
Lavalle-Gonzales 2013⁵⁸	366	R, DB, P	Sita 26	Canagliflozin	Metformin	7.9	−0.73	55.5	ITT	169
Schernanther 2013⁵⁹	378	R, DB, P	Sita 52	Canagliflozin	Met+Su	8.1	−0.66	56.7	ITT	166
Rhee 2013⁶⁰	133	R, DB, P	Sita 24	Gemegliptin	Metformin	8.05	−0.8	53	FAS	146
Charbonnel 2013⁶¹	269	R, OP, P	Sita 12	Liraglutide	Metformin	8.2	−0.8	57.6	ITT	174
Roden 2013⁶²	223	R, D, P	Sita 24	Empagliflozin	Naive	7.85	−0.66	55	ITT	147
Henry, 2014⁶³	172	R, DB, P	Sita 54	Multiple T	None	8.6	−1.1	51	ITT	178
Rosenstock, 2008⁶⁴	47	R, DB, P	Saxa 12	Placebo	Naive	7.9	−0.9	53.7	ITT	169
Defronzo, 2009⁶⁵	186	R, DB, P	Saxa 24	Placebo	Metformin	8.1	−0.69	54.7	FAS	180
Hollander, 2009⁶⁶	183	R, DB, P	Saxa 24	Placebo	Thiazol	8.4	−0.94	53.2	ITT	162
Rosenstock, 2009⁶⁷	106	R, DB, P	Saxa 24	Placebo	Naive	8.0	−0.46	53.9	FAS	172
Chacra, 2009⁶⁸	250	R, DB, P	Saxa 24	Glyburide	Glyburide	8.5	−0.64	54.9	ITT	175
Goke, 2010⁶⁹	293	R, DB, P	Saxa 52	Glipizide	Metformin	7.46	−0.74	57.5	PP	163
Scheen, 2010⁴⁵	343	R, DB, P	Saxa 18	Sitagliptin	Metformin	7.7	−0.52	58.8	PP	160
Yang, 2011⁷⁰	275	R, DB, P	Saxa 24	Placebo	Metformin	7.9	−0.78	53.8	FAS	155
Pan, 2012⁷¹	277	R, DB, P	Saxa 24	Placebo	Naive	8.1	−0.84	51.2	FAS	164
Fonseca, 2012⁷²	137	R, DB, P	Saxa 18	Metformin	Metformin	8.4	−0.88	55.2	FAS	162
Frederich, 2012⁷³	69	R, DB, P	Saxa 24	Placebo	Naive	8.0	−0.66	54.7	ITT	162
Hermans, 2012⁷⁴	146	R, DB, P	Saxa 24	Metformin	Metformin	7.7	−0.47	58.7	FAS	166
Moses, 2013⁷⁵	127	R, DB, P	Saxa 24	Placebo	Met+Su	8.4	−0.74	57.2	FAS	155
Forst, 2010⁷⁶	62	R, DB, P	Lina 12	Placebo	Metformin	8.5	−0.5	59.2	FAS	189
Taskinen, 2011⁷⁷	513	R, DB, P	Lina 24	Placebo	Metformin	8.1	−0.49	56.5	FAS	169
Owens, 2011⁷⁸	778	R, DB, P	Lina 24	Placebo	Met+Su	8.15	−0.72	58.3	FAS	158
Del Prato, 2011⁷⁹	333	R, DB, P	Lina 24	Placebo	None	8.0	−0.44	56.4	FAS	164
Haak, 2012⁸⁰	142	R, DB, P	Lina 24	Placebo	None	8.7	−0.5	56.2	FAS	194
Ross, 2012⁸¹	236	R, DB, P	Lina 12	Placebo	Metformin	8.0	−0.8	58.4	FAS	166
Lewin, 2012⁸²	158	R, DB, P	Lina 18	Placebo	Sulfonylurea	8.6	−0.54	57.2	FAS	182
Barnett, 2012⁸³	147	R, DB, P	Lina 18	Placebo	None	8.1	−0.39	56.4	FAS	183
Gallwitz, 2012⁸⁴	764	R, DB, P	Lina 104*	Glimepiride	Metformin	7.7	−0.38	59.8	FAS	164
Kawamori, 2012⁸⁵	159	R, DB, P	Lina 12	Placebo	Mixed	8.07	−0.24	60.3	FAS	164
Inagaki, 2013⁸⁶	124	R, OL, P	Lina 52	Metformin	Su	8.1	−0.7	61.3	FAS	155
Inagaki, 2013⁸⁶	61	R, OP, P	Lina 52	Metformin	Acarbose	7.9	−0.9	61	FAS	142
Barnett, 2013⁸⁷	160	R, DB, P	Lina 24	Placebo	Multiple	7.8	−0.61	74.9	FAS	153
DeFronzo, 2008⁸⁸	131	R, DB, P	Alo 26	Placebo	Naive	7.9	−0.59	53.4	FAS	NR
Nauck, 2009⁸⁹	207	R, DB, P	Alo 26	Placebo	Metformin	7.9	−0.6	54	FAS	171
Pratley, 2009⁹⁰	198	R, DB, P	Alo 26	Placebo	Glyburide	8.1	−0.53	56.5	FAS	NR
Pratley, 2009⁹¹	199	R, DB, P	Alo 26	Placebo	Thiazol	8.0	−0.8	55.4	FAS	169
Rosenstock, 2010⁹²	164	R, DB, P	Alo 26	Pioglitazone	Naive	8.8	−0.96	53	ITT	189
Seino, 2011⁹³	80	R, DB, P	Alo 12	Placebo	Naive	7.9	−0.76	59.5	FAS	NR
Bosi, 2011⁹⁴	397	R, DB, P	Alo 52	Pioglitazone	Met+Pio	8.2	−0.7	54.3	FAS	NR
Kaku, 2011⁹⁵	113	R, DB, P	Alo 12	Placebo	Pioglitazone	7.9	−0.97	59.3	FAS	NR
Seino, 2011⁹⁶	79	R, DB, P	Alo 12	Placebo	Voglibose	7.91	−0.91	62.9	FAS	NR
DeFronzo, 2012⁹⁷	129	R, DB, P	Alo 26	Placebo	Metformin	8.6	−0.92	53.7	FAS	184
Seino, 2012⁹⁸	96	R, DB, P	Alo 12	Placebo	Metformin	8.02	−0.64	52.3	FAS	NR

*Difference between HbA1c value at 52–54 weeks and baseline.
Alo, alogliptin; ATP, all treated population; Col, colesevelam; DB, double blind; Exen, exenatide; FAS, full analysis set; FG, fasting glucose; FU, follow-up; Glimep, glimepiride; HbA1c, glycated haemoglobin; ITT, intention-to-treat; Lina, linagliptin; Met, metformin; None, previous treatment discontinued; NR, not reported; OP, open label; P, parallel; Pio, pioglitazone; PP, per protocol; R, randomised; Rosi, rosiglitazone; Saxa, saxagliptin; Sita, sitagliptin; Su, sulfonylurea; Thiazol, thiazolidinedione; Vilda, vildagliptin.