Effects of metformin or rosiglitazone on serum concentrations of homocysteine, folate, and vitamin B12 in patients with type 2 diabetes mellitus

Association between metformin and vitamin B12 deficiency in patients with type 2 diabetes: A systematic review and meta-analysis

“…Five intervention studies were identified [37][38][39][40][41] of which only two were double blinded, randomised and placebo controlled [37,40]. The Hyperinsulinemia: the Outcome of its Metabolic Effects (HOME) trial was a prospective multi-centred RCT [37,40].…”

“…Four studies [38,39,41] [37] were suitable for inclusion in the meta-analysis. Three trials were of short duration [38,39,41] (≤4 months) and as the HOME trial data were present in two papers (interim analysis at 4 months [37] and final analysis at 4 years [40]), the HOME trial 4 months measurement [37] was chosen for the meta-analysis rather than the 4 year measurement [40].…”

“…Three trials were of short duration [38,39,41] (≤4 months) and as the HOME trial data were present in two papers (interim analysis at 4 months [37] and final analysis at 4 years [40]), the HOME trial 4 months measurement [37] was chosen for the meta-analysis rather than the 4 year measurement [40]. This was chosen in order for the HOME trial to be homogenous with the other trials in the meta-analysis.…”

Metformin Treatment and Homocysteine: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…Also, five papers did not provide any information about adverse events [26,29,31,32,34]. No death was reported.…”

“…The procedures of random sequence generation in seven studies [26,27,31,33,[35][36][37], of allocation concealment in nine studies [26][27][28]31,[33][34][35][36][37], and of blinding of participants and personnel in five studies [30,[32][33][34]36] were not clearly described. Selective reporting risk was unclear in one study [32].…”