Risk of diabetic foot ulceration during treatment with insulin glargine and NPH insulin.

OBJECTIVE

To evaluate the effect of the long-acting basal insulin analog glargine compared with neutral protamine Hagedorn (NPH) insulin on the incidence of diabetic foot ulceration (DFU) in patients with diabetes in Germany.

METHOD

A retrospective cohort study was performed using a representative German database (IMS Disease Analyzer) of patients with type 2 diabetes, who started a basal insulin therapy with either insulin glargine or NPH insulin, between July 2000 and September 2007, and continued this therapy for at least 24 months, and whose data were continuously documented.The occurrence of DFU was recorded beginning in the third year after therapy initiation and Kaplan-Meier curves were generated and compared using log-rank tests. Cox proportional hazard models were used to estimate the adjusted hazard ratio (HR) and 95% confidence intervals (CI) for the incidence of DFU.

RESULTS

Patients who fulfilled the inclusion criteria (n=23 395) had started either on insulin glargine (n=9638) or on NPH insulin (n= 13 757).After adjustment for demographic and clinical variables, it was demonstrated that the relative risk to diabetes patients of developing DFS is 64% lower with insulin glargine than with NPH insulin therapy (HR=0.6 I; p=0.0405).

CONCLUSION

The results suggest that, compared with NPH insulin, insulin glargine therapy significantly reduces the risk of DFS in patients with diabetes under real life conditions. Prospective long-term trials are needed to confirm these secondary data analysis results.

DECLARATION OF INTEREST

There were no external sources of funding for this study.The authors have no conflicts of interest to declare.