Increasing usage of continuous glucose monitoring (CGM) and recognition of the limitations of HbA1c lead to the adoption of new key metabolic parameters. Better understanding is needed as they are imposed as main metrics for the evaluation of patients with T1D.
Aim: To evaluate the correlation between time in range (TIR), hyperglycemia, estimated HbA1c and conventionally measured HbA1c.
A total of 43 families with child/children with T1D on pump treatment and continuous use of CGM were invited to participate in the study;31 (72.1%) families accepted.The children were followed for 6 months.Data from CGM was downloaded for 14 days 3-monthly.
The study group consists of 32 children with T1D,mean age 9.3±3.4y, 20(64.5%) boys,mean diabetes duration 4.9±1.9y; 24 (77.4%) of all are on sensor-augmented pump therapy; 5(16.1%) on OpenAPS and 2 (6.5%) are on the LOOP system.Mean duration of CGM usage is 3.0±1.3y. Mean HbA1c improved significantly at 6 months as follows: 6.9±1.0% vs. 6.8±1.0% (p =0.003).TIR strongly negatively correlated with HbA1c (baseline r=-0.77, 6th month r=-0.8) and with eHbA1c (r =-0.9, 3rd monthr =-0.8, 6th month r= -0.9).Time spent in hyperglycemia above 14 mmol/l influenced metabolic control only at the end of follow up period (r=0.8).Relationship between eHba1c and measured HbA1c is significant at the final evaluation (r=0.9, p=0.003).
There is strong correlation of eHbA1C, TIR and measured HbA1c which renders these key metrics preferred for assessing of an individual patient's glycemic control. Further studies may lead to their exclusive use also for predicting of the risk of diabetes complications.