Biphasic vs basal bolus insulin regimen in Type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

AimWe aim to evaluate the effects of biphasic insulin compared with a basal bolus insulin regimen on glycaemic control, total daily insulin requirements, risk of hypoglycaemia, weight and quality of life in patients with diabetes mellitus. MethodsMEDLINE, EMBASE, PubMed and Scopus databases were searched for studies up to November 2013. Interventions that lasted for more than four weeks and were reported in English were considered for the review. Meta-analysis was performed on eligible studies. ResultsFifteen randomized controlled trial studies, involving 4384 patients, were included. Greater HbA(1c) reductions were seen with basal-bolus compared with biphasic insulin regimens, between-treatment weighted mean difference (WMD) for baseline-to-endpoint changes in HbA(1c) was -0.2% (95% CI: -0.36 to -0.03) [-2.2 (-3.9, -0.3)mmol/mol]. In non-insulin naive (n=8) patients with Type2 diabetes, HbA(1c) reduction was greater in the basal bolus group; WMD=-0.22% (95% CI: -0.42 to -0.02) [-2.4 (-4.6, -0.2)mmol/mol], but in insulin naive patients (n=5), HbA(1c) was equivalent between the two regimens; WMD (-0.15% (95% CI: -0.52 to 0.22) [-1.6 (-5.7, 2.4)mmol/mol]. Total daily insulin requirements and weight were increased with both regimens, whereas hypoglycaemia rates were comparable between the two regimens. Greater HbA(1c) reduction was observed in the basal bolus group compared with the biphasic regimen at the expense of higher daily insulin requirements and weight gain, but with no greater risk of hypoglycaemia. ConclusionsBiphasic and basal bolus regimens were equally effective in reducing HbA(1c) in insulin naive patients with Type2 diabetes and both regimens are equally effective for initiating insulin in Type2 diabetes.