Introduction: HbA1c is an important guide for management, diagnosis and prediction of complications in diabetes. We have shown that young black patients with established T1D have higher HbA1c than white patients even after adjustment for mean blood glucose, RBC indices, age, and gender. We hypothesized that glucose-independent racial disparity in HbA1c is also present at diagnosis of T1D.
Methods: Data was collected by chart review for self-identified white and black patients who presented between Jan 2012 and Nov 2018 to the Hospital ER with untreated new onset T1D. Analyte data is from initial blood sample. Data was collected for date of birth, sex, self-identified race, weight, height, glucose, HbA1c, pH, bicarbonate, insulin, C-peptide, pancreatic autoantibodies, RBC indices. Simple correlation and comparison of means between groups was performed. This followed by multiple variable regression modeling to test the statistical effect of race, gender, age, glucose, RDW-CV and other variables on HbA1c.
Results. We included 191 children with newly diagnosed T1D (69 blacks and 122 whites; 116 M, 75 F). HbA1c was correlated with glucose, insulin, c-peptide, age, RDW-CV, Hb, HCO3. blacks had higher HbA1c 11.9 ±1.9 vs. whites 11.04±2 (P=0.004), higher glucoses 530.6±230.4 vs. 441.9±211.3 mg/dL (P=0.0075), lower C-peptides 0.57± 0.42 vs. 0.76±0.61 ng/mL (P=0.019) and lower pH 7.28±0.15 vs. 7.33±0.12, (P=0.02). There was no statistical difference in age, BMI-z, HCO3 or insulin between the groups. After adjusting for age, sex, glucose, C-peptide and RDW-CV, HbA1c is still higher in blacks, P=0.037. Age, gender, glucose, C-peptide and RDW-CV were also significant covariates in the model.
Conclusions. 1- HbA1c at presentation is influenced by Race, glucose, age, sex, RDW-CV, and c-peptide 2- Even after adjustment for glucose blacks have higher HbA1c than whites 3- Glucose-independent HbA1c racial difference should be taken into account for purposes of diagnosis and management of T1D.
A. Alaqeel: None. S. Chalew: None.