Glycaemic Control in People with Type 2 Diabetes Mellitus Switching from Basal Insulin to Insulin Glargine 300 U/ml (Gla-300): Results from the REALI Pooled Database

Introduction: Using pooled data from the REALI European database, we evaluated the impact of previous basal insulin (BI) type on real-life effectiveness and safety of switching to insulin glargine 300 U/ml (Gla-300) in people with suboptimally controlled type 2 diabetes. Methods: Patient-level data were pooled from 11 prospective, open-label, 24-week studies. Participants were classified according to the type of prior BI. Of the 4463 participants, 1282 (28.7%) were pre-treated with neutral protamine Hagedorn (NPH) insulin and 2899 (65.0%) with BI analogues (BIAs), and 282 (6.3%) had undetermined prior BI. Results: There were no meaningful differences in baseline characteristics between subgroups, except for a higher prevalence of diabetic neuropathy in the NPH subgroup (21.6% versus 7.8% with BIAs). Mean +/- standard deviation haemoglobin A1c (HbA1c) decreased from 8.73 +/- 1.15% and 8.35 +/- 0.95% at baseline to 7.71 +/- 1.09% and 7.82 +/- 1.06% at week 24 in the NPH and BIA subgroups, respectively. Least squares (LS) mean change in HbA1c was -0.85% (95% confidence interval -0.94 to -0.77) in NPH subgroup and -0.70% (- 0.77 to -0.64) in BIA subgroup, with a LS mean absolute difference between subgroups of 0.16 (0.06-0.26; p = 0.002). Gla-300 mean daily dose was slightly increased at week 24 by 0.07 U/kg/day (approximately 6 U/day) in both subgroups. Incidences of symptomatic and severe hypoglycaemia were low, without body weight change. Conclusions: Irrespective of previous BI therapy (NPH insulin or BIAs), switching to Gla-300 improved glycaemic control without weight gain and with low symptomatic and severe hypoglycaemia incidences. However, a slightly greater glucose-lowering effectiveness was observed in people pre-treated with NPH insulin.