Time in Range Does Not Associate With Carotid Artery Wall Thickness and Endothelial Function in Type 1 Diabetes

Patients with Type 1 diabetes (T1D) have an increased risk of developing atherosclerosis and complications as myocardial infarction and peripheral artery disease. The thickening of the carotid wall and the brachial artery dysfunction are early and preclinical manifestations of atherosclerosis. The standard marker of care for assessment of glycemic control, glycated hemoglobin, does not associate with early atherosclerosis. We have hypothesized that the emerging metric of glycemic control, as the time spent in the target range (TIR), might be associated with carotid thickening and endothelial dysfunction. According to the hypothesis, we have designed the present research with the aim to evaluate the association between TIR collected in the short and long term and the measures of arterial morphology and function in patients with T1D.

In our study, 70 patients and 35 healthy controls underwent ultrasound vascular study to measure carotid artery intima-media thickness (IMT) and brachial artery endothelial function by the flow-mediated dilation (FMD) technique. TIR was collected by a continuous glucose monitoring system for 2 weeks, 3 months, and 6 months before the vascular study.

Patients with T1D showed a significantly higher carotid IMT (mean±SE, 644±19 vs. 568±29 µ; p= 0.04) and a significantly lower FMD (mean±SE, 7.6±0.4 vs. 9.8±0.6%; p=0.01) compared with control subjects. No significant relationship between IMT, FMD, and TIR collected in the short and long term emerged.

Young patients with T1D have early vascular abnormalities. The percent of TIR does not correlate with preclinical atherosclerosis. This finding underlines the complexity of the interplay between diabetes and atherosclerosis.