1268-PUB: The Relationship of Time-in-Range (TIR) and HbA1c and the Factors That Contribute to a Better TIR

Abstract

Background: HbA1c, the current gold standard treatment target for patients with diabetes, cannot reveal the glucose fluctuation. Therefore, new metrics need to be incorporated with HbA1c to better understand the dynamic nature of glucose. As the use of continuous glucose monitoring (CGM) increases, there is a need to better understand key metrics of time in range 70-180 mg/dL (TIR). Methods: Patients with T2DM underwent a 48-h to 72-h CGM were included and divided into two groups: low TIR group (LTIR, TIR<70%) and high TIR group (HTIR, TIR≥70%). The characteristics between the two groups were compared. The relationship of HbA1c, glucose variability, time above range (TAR), time below range (TBR) and TIR were analyzed. And the contributions of BG and PPG increments to TIR were investigated. Results: A total of 110 patients were enrolled. The age, BMI, duration of disease, treatment types and the index of glucose variability were not statistically significant (P > 0.05) between the LTIR group (n=11) and the HTIR group (n=99). HbA1c (7.96±1.08% vs. 6.69±1.23%, p =0.002) and TAR (61.59±7.88% vs. 90.59±7.73%, p<0.001) were lower in the HTIR group than that in the LTIR group, but TBR did not differ between groups. We further evaluated the contributions of BG and PPG to TIR, It showed that the relative contributions of BG in the LTIR group and the HTIR group were(47%vs33 %, p = 0.045), while the relative contributions of PPG were (53% vs. 67%, p = 0.045)in the two groups, respectively. Conclusions: TIR is correlated with HbA1c and TAR, but not TBR, indicating the need to control the hyperglycemia for a better TIR. Furthermore, BG seems to a predominant contributor to a better TIR, and obviously exceed PPG in the T2DM patients with TIR >70%. Disclosure L. Gong: None. W. Xu: None. B. Lin: None. Z. Liu: None. D. Yang: None. C. Wang: None. B. Yao: None. Funding National Key Research and Development Program of China (2016YFC1304801)