No correlation between carotid intima-media thickness and long-term glycemic control in individuals with type 1 diabetes.

AIMS: To determine whether carotid intima-media thickness (CIMT), a surrogate marker of cardiovascular disease (CVD), is associated with long-term blood glucose control in individuals with type 1 diabetes (T1D). METHODS: We recruited 508 individuals (43.4% men; median age 46.1, IQR 37.8-55.9 years) with T1D (median diabetes duration of 30.4, IQR 21.2-40.8 years) in a cross-sectional retrospective sub-study, part of the Finnish Diabetic Nephropathy (FinnDiane) Study. Glycated hemoglobin (HbA1c) data were collected retrospectively over the course of ten years (HbA1c-meanoverall) prior to the clinical study visit that included a clinical examination, biochemical sampling, and ultrasound of the common carotid arteries. RESULTS: Individuals with T1D had a median CIMT of 606 µm (IQR 538-683 µm) and HbA1c of 8.0% (7.3-8.8%) during the study visit and HbA1c-meanoverall of 8.0% (IQR 7.3-8.8%). CIMT did not correlate with HbA1c (p = 0.228) at visit or HbA1c-meanoverall (p = 0.063). After controlling for relevant factors in multivariable linear regression analysis, only age was associated with CIMT (p < 0.001). After further dividing CIMT into quartiles, no correlation between long-term glucose control and CIMT (%, 1st 8.1 [IQR 7.2-8.9] vs 4th 7.9 [7.4-8.7], p = 0.730) was found. CONCLUSIONS: We observed no correlation between long-term blood glucose control and CIMT in individuals with T1D. This finding suggests that the development of early signs of macrovascular atherosclerosis is not strongly affected by the glycemic control in people with T1D.