Effects of switching from NPH insulin to insulin glargine in patients with type 2 diabetes: the retrospective, observational LAUREL study in Italy

The aim was to observe the effects of switching from neutral protamine Hagedorn (NPH) insulin to insulin glargine on glycaemic control in patients with type 2 diabetes mellitus (T2DM) in everyday clinical practice in Italy. This multicenter, observational, retrospective study included 1,011 patients with T2DM who switched from NPH insulin to glargine or were maintained on NPH insulin. The primary outcome was change in HbA1c over 4–8 months. Secondary outcomes included fasting blood glucose (FBG), insulin dose, and hypoglycaemia. The intention-to-treat population consisted of 996 patients (glargine 496; NPH 500). Prior to switching, HbA1c was higher in the glargine than the NPH group [mean (±SD) 8.8 ± 1.4 vs. 7.9 ± 1.2 %; p < 0.001]. HbA1c decreased after 4–8 months with glargine (8.2 ± 1.4 %; p < 0.001) but not with NPH (8.0 ± 1.4 %; p = 0.20). Similar results were observed for FBG. The daily dose of glargine increased from 0.22 ± 0.10 U/kg at the switch to 0.26 ± 0.11 U/kg at study end, while the NPH dose remained stable (0.19 ± 0.09–0.20 ± 0.09 U/kg). While not statistically significant, the percentage of patients with hypoglycaemic episodes during the last month of treatment tended to be less with glargine. No significant change in body weight occurred in either group. Switching patients from NPH insulin to insulin glargine in a real-life setting was associated with significant improvement in glycaemic control. The increase in glargine dose was not accompanied by increased hypoglycaemia or weight gain.