ETHNIC-DIFFERENCES IN THE GLYCEMIC RESPONSE TO EXOGENOUS INSULIN-TREATMENT IN THE VETERANS AFFAIRS COOPERATIVE STUDY IN TYPE-2 DIABETES-MELLITUS (VA CSDM)

OBJECTIVE - The Veterans Affairs Cooperative Study in Type 2 Diabetes Mellitus was conducted in NIDDM patients to determine if a significant difference in HbA(1c) could be achieved between groups receiving stan dard and intensive treatment. We observed differences in the response to exogenous insulin between African-Americans and other intensively t reated patients. Therefore, we assessed the variations of response and correlated factors that might explain such differences. RESEARCH DESI GN AND METHODS - One hundred fifty-three men aged 40-69 years with NID DM for less than or equal to 15 years were randomized to either the st andard therapy (n = 78) or the intensive therapy (n = 75) arm. Of the 75 patients in the intensive therapy group, 57 completed the study on insulin therapy alone. Of these, 18 were African-Americans and 39 were non-African-Americans. We conducted an analysis of the data collected to determine differences in baseline characteristics, glycemic respon se, insulin requirement, body weight, exercise, and basal C-peptide le vel, factors that may explain a difference in response to insulin ther apy. RESULTS - Glycemic control improved in all patients with intensiv e insulin therapy African-Americans achieved a greater improvement in HbA(1c) compared with non-African-Americans with a similar increment i n insulin. This difference could not be explained by differences in bo dy weight, activity, concomitant use of other medicines, or insulin-se cretory capacity of the pancreas. CONCLUSIONS - We conclude that ethni c differences may exist in the response to insulin therapy. A knowledg e of such differences may aid in achieving good glycemic control, espe cially since minorities have a greater prevalence of and burden from t he microvascular complications of diabetes.