Improved glycaemic control by switching from insulin NPH to insulin glargine: a retrospective observational study

Background: Insulin glargine (glargine) and insulin NPH (NPH) are two basal insulin treatments. This study investigated the effect on glycaemic control of switching from a NPH-based regimen to a glargine-based regimen in 701 patients with type 1 (n= 304) or type 2 (n= 397) diabetes, using unselected primary care data. Methods: Data for this retrospective observational study were extracted from a UK primary care database (The Health Improvement Network). Patients were required to have at least 12 months of data before and after switching from NPH to glargine. The principal analysis was the change in HbA1c after 12 months treatment with glargine; secondary analyses included change in weight and total daily insulin dose. Inconsistent reporting of hypoglycemic episodes precludes reliable reporting of this outcome. Multivariate analyses were used to adjust for baseline characteristics and confounding variables. Results: After adjustment, both diabetic cohorts showed statistically significant reductions in mean HbA1c 12 months after the switch, by 0.38% (p 0.05). Conclusion: In routine clinical practice, switching from NPH to glargine provides the opportunity for improving glycaemic control in diabetes patients inadequately controlled by NPH.Peter Sharplin, Jason Gordon, John R Peters, Anthony P Tetlow, Andrea J Longman and Philip McEwa