Glycated hemoglobin is not enough: The role of glycemia risk index for glycemic control assessment in type 1 diabetes.

BACKGROUND

Glycated hemoglobin (HbA1c), the gold standard for assessing glycemic control, has limited ability to reflect the risks of hypoglycemia and glycemic variability, raising great concerns, especially in patients with type 1 diabetes (T1D). The glycemia risk index (GRI), a composite metric derived from continuous glucose monitoring (CGM), has emerged as a potential solution by systematically integrating both hypoglycemia and hyperglycemia risks into a single interpretable score.

AIM

To evaluate whether the GRI addresses HbA1c limitations.

METHODS

We analyzed 328 patients with T1D using 681 CGM and clinical data points. Linear mixed-effects models were used to address the relationship between the GRI and HbA1c within repeated-measures data. Correlation and cluster analyses were used to assess the comprehensive GRI reflection of seven key ambulatory glucose profile parameters.

RESULTS

The GRI exhibited linear correlations with HbA1c ( = 0.53), time in range ( = -0.90), time above range ( = 0.63), time below range (TBR) ( = 0.37), and coefficient of variation (CV) ( = 0.71). It correlated strongly with TBR and CV than HbA1c. The association between HbA1c levels and GRI was influenced by TBR and CV. At a given HbA1c, each 1% increase in TBR or CV raised GRI by 1.87 [95% confidence interval (CI): 1.72-2.01] and 1.94 (95%CI: 1.80-2.10), respectively ( < 0.001). Clustering of the CGM data identified four subgroups: Moderate-risk glycemic fluctuations, high-risk hypoglycemia, optimal glycemic control, and high-risk hyperglycemia. The GRI and its components for hypoglycemia and hyperglycemia could distinguish between these subgroups.

CONCLUSION

The GRI offers a comprehensive view of glycemic control in T1D. Combining HbA1c with the GRI enables accurate assessment for managing glycemic control in patients with T1D.