Safety and efficacy of glargine compared with NPH insulin for the treatment of Type 2 diabetes: a meta-analysis of randomized controlled trials

Aims We systematically analysed evidence from randomized controlled trials (RCTs) examining the safety and efficacy of neutral protamine Hagedorn (NPH) insulin and glargine in the management of adults with Type 2 diabetes. Methods Studies were identified by searching MEDLINE (1966-March 2007), EMBASE (1974-2007), American Diabetes Association abstract database and the Cochrane Central Register of Controlled Trials using Medical Subject Headings (MeSH) diabetes mellitus, Type 2, insulin, insulin isophane, hypoglycaemic agents and the keywords glargine and NPH. Data on study design, participants, fasting plasma glucose (FPG), glycated haemoglobin (HbA(1c)), body weight and hypoglycaemia were independently abstracted by two investigators using a standardized protocol. Results Data from a total of 4385 participants in 12 RCTs were pooled using a random-effects model. The mean net change (95% confidence interval) for FPG, HbA(1c) and body weight for patients treated with NPH insulin as compared with glargine was 0.21 mmol/l (-0.02 to 0.45), 0.08% (-0.04 to 0.21) and -0.33 kg (-0.61 to -0.06), respectively, with negative values favouring NPH and positive values favouring glargine. More participants experienced symptomatic and nocturnal hypoglycaemia on NPH than glargine, but there was no significant difference in confirmed or severe episodes. Conclusions We identified no difference in glucose-lowering between insulin glargine and NPH insulin, but less patient-reported hypoglycaemia with glargine and slightly less weight gain with NPH in adults with Type 2 diabetes.