Introduction: The relationship of A1c vs. GMI across race/ethnicity has significant differences between Non-Hispanic White (NHW) vs. Non-Hispanic Black (NHB) adults; however, data in ethnically diverse children are lacking. We assessed the correlation of A1c vs. GMI in a large, diverse pediatric population with T1D.
Methods: T1D youth with ≥70% CGM use over the prior 14 days at the time of A1c were included. Delta (defined as GMI minus A1c) was categorized as ≤-0.5%, >-0.5 to <0.5%, ≥0.5% with absolute value of ≥0.5% considered clinically significant. Proportional odds regression was used to evaluate if race/ethnicity was associated with larger difference category.
Results: In 969 youth (age 11.6 ± 3.8y; 53% female; T1D duration 4.4 ± 3.4y), mean A1c was 7.71% and mean GMI was 7.98%. Delta overall and across race/ethnicity are presented in Table 1. Hispanic (OR 2.17; 95% CI 1.44-3.26; p<0.001) and NHW (OR 2.22; 95% CI 1.53-3.22; p<0.001) youth had significantly higher likelihood of having Delta (GMI - A1c) of ≥0.5% compared to NHB youth.
Conclusion: In this diverse pediatric population with T1D, NHW and Hispanic youth were more likely to have a clinically significant discrepancy in which GMI is greater than A1c as compared to NHB youth. Clinical relevance of the A1c vs. GMI relationship, including which best predicts risk of micro- and macrovascular complications, warrants further study.
A.F. Siller: None. J.K. Sickler: None. C. Villegas: None. X.C. Huang: None. C.G. Minard: None. M.J. Redondo: None. D. DeSalvo: Advisory Panel; Insulet Corporation. Consultant; Dexcom, Inc.
