Differences in circulating insulin levels following glargine administration

Objectives: To evaluate two-site non competitive insulin immunoassays [BI-INSULIN assay (IRMA) and an electro-chemiluminescent immunoassay (ECLIA)] in routine practice. Design and methods: We studied 145 consecutive patients attending our Endocrine Department for general endocrine explorations and metabolic status investigations. Results: The ECLIA yielded higher results than IRMA in all but six patients treated by glargine. Conclusions: Insulin levels measured by Elecsys in patients treated by glargine are directly related to glargine biotransformation into detectable metabolite (M1).