Table 1.

Treatment effects of glucose-lowering drugs added to metformin compared with metformin monotherapy.

Therapy	HbA1c, %	FPG, mmol/L	2 hPG, mmol/L	BMI, kg/m2	TC, mmol/L	HDL-C, mmol/L	SBP, mmhg	Hypoglycemia
TZD	−0.79 [−0.99, −0.60] *	−1.04 [−1.24, −0.84] *	−1.71 [−2.00, −1.42] *	−0.07 [−1.24, 1.10]	−0.38 [−0.63, −0.13] *	0.18 [−0.39, 0.75]	—	1.16 [0.60, 2.22]
	I2 = 90.9%	I2 = 86.5%	I2 = 84.5%	I2 = 93.4%	I2 = 81.7%	I2 = 98.3%		I2 = 0.0%
Rosiglitazone	−0.73 [−1.03, −0.42] *	−1.11 [−1.39, −0.83] *	−1.75 [−2.40, −1.10] *	−1.23 [−2.51, 0.06]	−0.03 [−0.21, 0.15]	—	—	1.46 [0.51, 4.18]
Pioglitazone	−0.83 [−1.07, −0.58] *	−1.03 [−1.27, −0.78] *	−1.66 [−1.96, −1.36] *	0.51 [−0.49, 1.51]	−0.61 [−0.87, −0.36] *	0.18 [−0.39, 0.75]	—	1.00 [0.43, 2.30]
DPP-4i	−0.99 [−1.09, −0.89] *	−1.10 [−1.20, −1.00] *	−1.76 [−1.91, −1.61] *	−1.19 [−1.55, −0.83] *	−0.71 [−0.85, −0.57] *	0.32 [0.21, 0.43] *	−5.40 [−10.98, 0.18]	0.77 [0.61, 0.98] *
	I2 = 80.5%	I2 = 73.1%	I2 = 70.9%	I2 = 92.3%	I2 = 79.9%	I2 = 93.2%	I2 = 89.2%	I2 = 0.0%
Sitagliptin	−1.08 [−1.24, −0.93] *	−1.26 [−1.41, −1.11] *	−2.03 [−2.22, −1.83] *	−1.66 [−1.99, −1.33] *	−0.90 [−1.12, −0.67] *	0.41 [0.26, 0.56] *	−12.12 [−18.10, −6.15] *	0.74 [0.55, 1.01]
Saxagliptin	−0.80 [−0.96, −0.63] *	−0.91 [−1.12, −0.69] *	−1.44 [−1.70, −1.17] *	−0.41 [−0.87, 0.05]	−0.48 [−0.89, −0.07] *	0.01 [−0.11, 0.13]	−1.20 [−7.65, 5.25]	0.98 [0.56, 1.72]
Vildagliptin	−0.76 [−0.89, −0.63] *	−0.85 [−1.05, −0.66] *	−1.20 [−1.66, −0.73] *	−0.82 [−1.38, −0.26] *	−0.33 [−0.49, −0.16] *	0.18 [−0.14, 0.49]	0.14 [−10.11, 10.39]	0.65 [0.34, 1.27]
Linagliptin	−0.90 [−1.17, −0.63] *	−1.15 [−1.47, −0.83] *	−1.97 [−2.37, −1.58] *	−2.11 [−4.60, 0.39]	−0.87 [−1.86, 0.13]	0.25 [−0.25, 0.75]	−4.00 [−8.56, 0.56]	0.72 [0.28, 1.87]
Alogliptin	−1.35 [−1.90, −0.80] *	−1.08 [−1.33, −0.82] *	−1.31 [−1.86, −0.77] *	−0.43 [−2.68, 1.82]	−0.63 [−0.72, −0.53] *	0.40 [0.28, 0.52] *	−0.29 [−4.24, 3.66]	1.00 [0.06, 15.73]
AGI	−1.03 [−1.25, −0.80] *	−0.97 [−1.12, −0.82] *	−1.65 [−1.92, −1.39] *	−1.75 [−2.48, −1.02] *	−1.08 [−1.37, −0.78] *	0.37 [0.26, 0.47] *	−3.82 [−8.12, 0.47]	0.76 [0.46, 1.26]
	I2 = 90.1%	I2 = 66.6%	I2 = 76.0%	I2 = 0.0%	I2 = 87.3%	I2 = 78.8%	I2 = 41.1%	I2 = 0.0%
Acarbose	−1.03 [−1.26, −0.79] *	−0.99 [−1.15, −0.83] *	−1.63 [−1.90, −1.36] *	−1.75 [−2.48, −1.02] *	−1.08 [−1.37, −0.78] *	0.37 [0.26, 0.47] *	−3.82 [−8.12, 0.47]	0.75 [0.44, 1.26]
Voglibose	−1.15 [−1.96, −0.34] *	−1.33 [−2.04, −0.62] *	−3.29 [−4.39, −2.19] *	—	—	—	—	1.00 [0.02, 49.17]
Miglitol	−1.04 [−1.97, −0.11] *	−0.48 [−0.98, 0.02]	−1.27 [−2.13, −0.40] *	—	—	—	—	1.00 [0.11, 9.47]
SGLT2i	−1.07 [−1.43, −0.71] *	−0.87 [−1.11, −0.62] *	−1.44 [−1.81, −1.07] *	−1.52 [−2.06, −0.98] *	−0.50 [−0.87, −0.13] *	0.21 [−0.03, 0.46]	−6.65 [−9.18, −4.13] *	1.00 [0.38, 2.64]
	I2 = 86.6%	I2 = 34.1%	I2 = 39.7%	I2 = 39.1%	I2 = 79.0%	I2 = 87.2%	I2 = 0.0%	I2 = 0.0%
Dapagliflozin	−1.02 [−1.45, −0.59] *	−0.84 [−1.11, −0.57] *	−1.38 [−1.78, −0.98] *	−1.39 [−2.05, −0.73] *	−0.54 [−0.93, −0.15] *	0.23 [−0.04, 0.51]	−6.46 [−10.42, −2.50] *	1.00 [0.34, 2.94]
Empagliflozin	−1.28 [−1.83, −0.73] *	−1.22 [−1.97, −0.47] *	−1.88 [−2.97, −0.79] *	−1.90 [−2.55, −1.25] *	−0.10 [−1.08, 0.88]	0.10 [−0.36, 0.56]	−6.61 [−11.16, −2.06] *	1.00 [0.11, 9.47]
INS	−1.12 [−1.42, −0.82] *	−1.58 [−1.94, −1.22] *	−2.52 [−3.20, −1.83] *	−0.45 [−1.05, 0.16]	−0.48 [−0.70, −0.27] *	0.40 [0.16, 0.64] *	—	0.58 [0.30, 1.10]
	I2 = 83.9%	I2 = 77.9%	I2 = 88.5%	I2 = 0.0%	I2 = 0.0%	I2 = 0.0%		I2 = 20.7%
Insulin	−1.12 [−1.42, −0.82] *	−1.58 [−1.94, −1.22] *	−2.52 [−3.20, −1.83] *	−0.45 [−1.05, 0.16]	−0.48 [−0.70, −0.27] *	0.40 [0.16, 0.64] *	—	0.58 [0.30, 1.10]
GLP-1RA	−1.14 [−1.28, −1.01] *	−1.33 [−1.53, −1.14] *	−1.68 [−1.94, −1.42] *	−1.96 [−2.36, −1.57] *	−0.94 [−1.15, −0.72] *	0.11 [0.01, 0.21] *	−5.25 [−8.18, −2.33] *	0.54 [0.34, 0.85] *
	I2 = 71.0%	I2 = 82.0%	I2 = 49.7%	I2 = 80.9%	I2 = 62.7%	I2 = 87.0%	I2 = 0.0%	I2 = 0.0%
Exenatide	−0.74 [−0.94, −0.55] *	−1.26 [−1.66, −0.87] *	−1.59 [−2.45, −0.73] *	−2.11 [−3.78, −0.44] *	−1.11 [−1.59, −0.62] *	0.04 [−0.06, 0.15]	−0.40 [−9.83, 9.03]	1.00 [0.11, 9.48]
Liraglutide	−1.21 [−1.36, −1.06] *	−1.35 [−1.57, −1.14] *	−1.70 [−1.98, −1.42] *	−1.97 [−2.36, −1.58] *	−0.90 [−1.15, −0.66] *	0.12 [0.01, 0.24] *	−5.77 [−8.85, −2.69] *	0.53 [0.33, 0.84] *
SU	−1.16 [−1.43, −0.90] *	−1.32 [−1.66, −0.98] *	−1.90 [−2.33, −1.48] *	−0.24 [−0.99, 0.51]	—	−0.14 [−0.34, 0.05]	−3.04 [−6.98, 0.89]	1.31 [0.67, 2.58]
	I2 = 88.3%	I2 = 91.0%	I2 = 83.4%	I2 = 46.2%		I2 = 0.0%	I2 = 0.0%	I2 = 0.0%
Glimepiride	−1.14 [−1.55, −0.74] *	−1.24 [−1.72, −0.76] *	−1.81 [−2.45, −1.16] *	−0.15 [−2.08, 1.79]	—	—	—	1.49 [0.54, 4.10]
Gliclazide	−1.70 [−2.72, −0.68] *	−1.88 [−3.03, −0.72] *	−1.70 [−2.76, −0.65] *	−0.10 [−0.67, 0.47]	—	−0.16 [−0.37, 0.05]	−1.90 [−7.19, 3.39]	0.74 [0.14, 3.83]
Glipizide	−0.86 [−1.13, −0.59] *	−1.01 [−1.38, −0.64] *	−2.07 [−2.48, −1.66] *	−0.80 [−2.65, 1.05]	—	—	—	1.51 [0.34, 6.77]
Gliquidone	−1.52 [−1.84, −1.20] *	−2.20 [−2.62, −1.78] *	−2.97 [−3.64, −2.30] *	—	—	0.00 [−0.64, 0.64]	−4.45 [−10.33, 1.43]	0.74 [0.02, 35.42]
NIDE	−1.29 [−1.60, −0.97] *	−1.43 [−1.83, −1.03] *	−1.90 [−2.47, −1.34] *	—	—	—	—	0.85 [0.28, 2.59]
	I2 = 80.0%	I2 = 75.1%	I2 = 81.6%					I2 = 0.0%
Repaglinide	−1.29 [−1.60, −0.97] *	−1.43 [−1.83, −1.03] *	−1.90 [−2.47, −1.34] *	—	—	—	—	0.85 [0.28, 2.59]

For HbA1c, FPG, 2 hPG, BMI, TC, HDL-C, and SBP, data are WMDs and 95% CIs; for hypoglycemia, data are RRs and 95% CIs. * Statistically significant differences. Table 1 were summary results from Supplementary Materials Figures S2–S58. A 2 hPG, 2 h postprandial plasma glucose. AGI, α-glucosidase inhibitor. BMI, body mass index. CI, confidence interval. DPP-4i, dipeptidyl peptidase 4 inhibitor. FPG, fasting plasma glucose. GLP-1RA, glucagon-like peptide-1 receptor agonist. HbA1c, hemoglobin Alc. HDL-C, high density lipoprotein-cholesterol. INS, insulin. MET, metformin. NIDE, glinide. RR, risk ratio. SBP, systolic blood pressure. SGLT2i, sodium-glucose cotransporter 2 inhibitor. SU, sulfonylurea. TC, total cholesterol. TZD, thiazolidinedione. WMD, weighted mean difference.