Table 1.
Study and studied subjects’ characteristics
| Study characteristics | MET treatment | Patient characteristics | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Reference | Aim of study |
total analyzed (n) |
preexisting or started (P/S) | dosage (mg/day) | treatment form XR/IR | age (mean ± SD) |
male (n/%) |
BMI at baseline (kg/m2) |
FBG (mg/dl) (mean ± SD) |
PBG (mg/dl) (mean ± SD) |
HbA1c (%) (mean ± SD) |
| Aladhab et al., 2023 [24] | To detect the association of the OCT1 genetic polymorphism with the efficacy and GI AE of metformin in newly diagnosed T2DM and drug naïve patients | 102 | S | 1000 | IR | 52.24 ± 10.74 | 54/52.9 | NR | NR | NR | NR |
| Alibrahim et al., 2023 [25] | To study the effect of variables that may influence the development of metformin side effects and/or intolerance | 148 | NR | 2000 | NR | 49.1 ± 6.6 | 72/48.6 | 31.89 | 175.83 ± 36.86 | 235.99 ± 102.46 | 9.55 ± 1.46 |
| Al-Waeli et al. 2022 [26] | To determine the barriers interfering with optimal metformin dosage | 475 | NR | 729,789 | NR | 56.2 ± 9.9 | 201/42.3 | 30.6 | 196.73 ± 79.87 | 260.73 ± 101.77 | 9.89 ± 2.65 |
| Asche et al., 2008 [27] | Evaluation of AE of metformin, sulfonylureas and thiazolidinediones in geriatric patients | 5438 | S | NR | NR | 72.2 ± 5 | 977/42 | 31.4 | NR | NR | 7.5 ± 1.5 |
| Dandona et al., 1983 [28] | To determine the prevalence of diarrhea in biguanide treated patients | 285 | P | NR | NR | NR | NR | NR | NR | NR | NR |
| Das et al., 2021 [29] | To evaluate the clinical characteristics, treatment patterns, and clinical effectiveness and safety of high doses of metformin in Indian adults with T2DM | 5695 | P | 2500 | NR | 50 ± 2.43 | 3480/62.7 | 27.7 | 114.75 ± 4.86 | 176.25 ± 8 | NR |
| De Jong et al., 2016 [30] | Frequency, latency time, outcome and management of AE related to the use of metformin | 2490 | S | NR | NR | 59.2 ± 10.2 | 1478/59.4 | 29.6 | NR | NR | NR |
| Florez et al., 2010 [31] | Impact of metformin on GI symptoms and HRQL and metformin-associated GI AE in patients with T2DM newly beginning therapy | 360 | S | NR | NR | 67 ± 15.5 | 140/38.9 | NR | NR | NR | NR |
| Huang et al., 2015 [21] | An assessment of whether Helicobacter pylori infection could influence on metformin tolerance in patients with T2DM | 415 | S | 1089 | IR | 64 ± 11.6 | 228/54.9 | 25.34 | 132.5 ± 42.8 | NR | 8.4 ± 2 |
| Kim et al., 2012 [22] | Tolerability and antihyperglycemic efficacy of metformin XR in the treatment of patients with T2DM from six Asian countries | 3556 | S | 840 | XR | 57.2 ± 11.5 | 1727/47.6 | 25.27 | 199.6 ± 63.7 | NR | 8.04 ± 1.35 |
| Levy et al., 2010 [23] | The efficacy, tolerability and patient satisfaction of an XR formulation of metformin in patients with T2DM | 61 | P | 1500 | XR | 54.1 ± 12.1 | 21/34.4 | 31.18 | NR | NR | 7.6 ± 1.5 |
| Malik et al., 2023 [32] | To evaluate efficacy and safety of various oral antidiabetic drugs/regimens used for T2DM patients | 248 | NR | NR | NR | NR | 140/56.4 | NR | 135.1 ± 13.2 | 193.12 ± 20 | 7.82 ± 0.6 |
| Memon et al., 2022 [33] | To analyze and compare the pharmacological efficacy of sitagliptin and metformin in terms of blood glucose and glycated HbA1c T2DM patients | 100 | NR | NR | NR | 49.7 ± 6.5 | NR | NR | 235.9 ± 32.5 | 421.5 ± 27.5 | 12.5 ± 2.7 |
| Mishra et al., 2021 [34] | To monitor AE of anti-diabetic medication in OPD of tertiary care hospital of northern India | 120 | NR | NR | NR | NR | 68/56.7 | NR | NR | NR | NR |
| Okayasu et al., 2012 [35] | Evaluation of AE and further analyzed risk factors in Japanese patients with T2DM who initially administered metformin | 101 | S | 621 | IR | 60.7 ± 14.86 | 62/61.4 | 24.7 | NR | NR | 9.4 ± 2.2 |
| Raičević et al., 2023 [36] | To investigate possible risk factors for the occurrence of GI complaints in patients on MTF therapy | 330 | S | 1000 | NR | 64 ± 14.7 | 141/42.7 | 26.64 | NR | NR | NR |
| Riyaz et al., 2014 [37] | To compere sitagliptin to metformin as an initial monotherapy in patients with T2DM | 100 | NR | 2000 | IR | NR | NR | NR | NR | NR | 7.95 ± NR |
| Sadeeqa et al., 2019 [38] | To investigate the effect of metformin-induced GI problems and its prevalence | 300 | P | 673 | IR | NR | 77/33.9 | NR | NR | NR | NR |
| Strojek et al., 2016 [39] | To assess adherence and tolerability of metformin XR formulation in patients with T2DM | 4737 | P | 1667 | XR | 60.6 ± 9.4 | 2269/47.9 | 30.5 | 122 ± 24 | 152 ± 32 | 7.05 ± 0.86 |
| Sumitani et al., 2012 [40] | Effectiveness of metformin and lifestyle interventions as an initial treatment in Japanese patients with newly diagnosed T2DM | 23 | S | 1435 | IR | 53 ± 11 | 20/87 | 25.7 | 182 ± 59 | NR | 9.1 ± 2.1 |
| Umamaheswaran et al., 2015 [41] | The impact of SLC22A1 rs622342 gene polymorphism on the clinical efficacy of metformin in South Indian T2DM patients | 122 | S | 2250 | IR | 49.57 ± 9.88 | 47/38.5 | 25.8 | 185.9 ± 49.2 | 290.7 ± 63.3 | 8 ± 0.2 |
NR Not reported, HRQL Health-related quality of life, T2DM Type 2 diabetes mellitus