Black youth with T1D have been noted to have higher HbA1c’s, less frequent monitoring of capillary glucose and higher reported occurrence of hypoglycemia compared to white patients. We hypothesized that this combination of factors would be associated with higher prescribed doses of insulin in black patients compared to whites. A retrospective analysis was performed on data collected from patients at the Children’s Diabetes Center, New Orleans, LA who participated in a study of racial differences in hemoglobin glycation. Patients self-identified as either black or white and were under the clinical care of several different attending diabetologists. The influence of race on total daily prescribed dose of insulin per kg body weight (TDDI), was evaluated in a general linear model adjusted for HbA1c, insulin delivery method, gender, and chronologic age as well as the interactive effect of race and HbA1c. Hemoglobin Glycation Index (HGI) was also calculated and substituted in the model for HbA1c. The population studied consisted of 33 (19F, 14M) black patients and 52 (22F,30 M)whites. Average age was 14.0±3.6 years and duration of diabetes 5.7±3.9 years. As previously reported from this population blacks had higher HbA1c even after adjustment for age and mean blood glucose level (MBG). Mean TDDI was 0.89±0.33 units/kg/d. TDDI was highly correlated with both HbA1c (r=0.40,p<0.0001)and MBG (r=0.43,p<0.0001) before adjustment. In the linear model TDDI was significantly associated with HbA1c (p=0.0003) but not race, age, gender or insulin delivery mode. There was no interactive effect of race and HbA1c. There was no significant effect of HGI. We found that prescribed TDDI increased with increasing HbA1c in both black and white patients. This preliminary study suggests that prescribing physicians increase insulin dosage in an attempt to bring HbA1c to goal for their patients but do not vary dose based on ethnicity.
S. Chalew: None. R. Gomez: None. J.M. Hempe: None.