136-LB: The Implication of Glycemic Risk Index Varies with Different Levels of Glycosylation A1c (HbA1c) in Type 1 Diabetes

Abstract

Objective: Type 1 diabetes (T1D) is characterized by significant fluctuations in blood glucose, necessitating comprehensive assessment of glycemic control. The Glucose Risk Index (GRI) is a new glucose assessment metric derived from continuous glucose monitoring (CGM) that can simultaneously indicate hyperglycemic and hypoglycemic risks. This study explored the implications of GRI for T1D with different HbA1c levels. Methods: We obtained 507 CGM and clinical data points from 281 patients with T1D, some of whom had follow-up data with intervals of over 3 months. The included patients aged 4-72 years with duration greater than 3 months and wore a CGM for at least 14 days. The hypoglycemic index and hyperglycemic index were calculated by time below range (TBR) <54 mg/dL + 0.8 × TBR <70-54 mg/dL and time above range (TAR) >250 mg/dL) + 0.5 × TAR >180-250 mg/dL, respectively. GRI is the sum of 3 times hypoglycemic index and 1.6 times hyperglycemic index. Relationships between GRI and HbA1c, each CGM metrics were explored and compared in patients with HbA1c <7% and ≥7%. Results: The mean GRI and HbA1c were 57.6 ± 20.6 and 7.3 ± 1.1%, respectively, and HbA1c of 7% approximately corresponded to GRI of 55. GRI was correlated with HbA1c (R = 0.536), hypoglycemic index (R = 0.466) and hyperglycemic index (R = 0.654), but the correlation between GRI and HbA1c disappeared in subgroup with HbA1c <7%. Compared with the HbA1c ≥7% group, GRI in the HbA1c <7% group had a stronger correlation with hypoglycemic index and a weaker correlation with hyperglycemic index. Further analysis showed the combination of dichotomous HbA1c (<7% or ≥7%) and GRI (<55 or ≥55) conferred best evaluation of glycemic control. Conclusions: The implication of GRI varies with different levels of HbA1c in T1D, with GRI mainly representing hypoglycemic risk when HbA1c <7%, and hyperglycemic risk when HbA1c ≥7%. A more comprehensive assessment of glycemic control in T1D should be the combination of dichotomous HbA1c and GRI. Disclosure B. He: None. Y. Xie: None. X. Li: None. Z. Zhou: None. Funding National Natural Science Foundation of China (81600649)