Race/Ethnicity Plays A Role in the Efficacy of Insulin Regimens

The object of the study was to explore the impact of race/ethnicity on the efficacy and safety of commonly used insulin regimens in patients with Type 2 diabetes.

In this post hoc analysis, pooled data from 11 multinational clinical trials involving 1455 patients with Type 2 diabetes were used to compare specific insulin treatments in Latino/Hispanic, Asian, African-descent, and Caucasian patients. Insulin treatments included once daily insulin glargine or neutral protamine Hagedorn (BASAL), insulin lispro mix 75/25 twice daily (LMBID), or insulin lispro mix 50/50 three times daily (LMTID). 

The results showed that, race/ethnicity was associated with significant outcome differences for each of the insulin regimens. BASAL therapy was associated with greater improvement in several measures of glycemic control among Latino/Hispanic patients compared with Caucasian patients (lower end point hemoglobin A_1c, greater reduction in hemoglobin A_1c from baseline, and a larger proportion of patients achieving hemoglobin A_1c level <7%). In contrast, LMBID therapy was associated with higher end point hemoglobin A_1c and a smaller decrease in hemoglobin A_1c from baseline in Latino/Hispanic and Asian patients than in Caucasian patients. Furthermore, fewer Asian patients attained a hemoglobin A_1c level <7% than did Caucasians patients. For LMTID therapy, hemoglobin A_1c outcomes were comparable across patient groups. Fasting blood glucose and glycemic excursions varied among racial/ethnic groups for the 3 insulin regimens. Weight change was comparable among racial/ethnic groups in each insulin regimen. During treatment with LMTID, Asian patients experienced higher incidence and rate of severe hypoglycemia than Caucasian patients.

Treating to appropriate HbA_1c targets is crucial to reduce the risk of development or progression of diabetes complications in patients with Type 2 diabetes. The world is currently facing an unprecedented epidemic of Type 2 diabetes that is disproportionately affecting non-Caucasian racial and ethnic populations. Results of post hoc studies such as this should be interpreted with caution. However, the researchers comment, "Our concurrent analysis of treatment responses to insulin therapy in four conventionally defined racial/ethnic populations is evidence of the need for future robust trials that discriminate treatment efficacy and safety differences through a better understanding of the interplay between culture and genetics. Such research may be possible in ongoing or future prospective clinical trials and in large observational studies in naturalistic clinical practice settings that recruit and enroll sufficient numbers of Type 2 diabetic patients with diverse racial/ethnic backgrounds. Through such studies, more targeted and tailored approaches to insulin therapy may be identified and proposed for further testing and clinical application."

Endocrine Practice. 2010;16(5):818-828