Dose-Dependent association of cumulative tobacco consumption with the presence of carotid atherosclerosis in individuals with type 1 diabetes.

Aims: Evaluate the association between cumulative tobacco consumption (CTC; packs-year) and atherosclerosis in type 1 diabetes (T1D), and study whether the inclusion of CTC in the Steno T1 Risk Engine (ST1RE) equation improves the identification of plaques.

Methods: Cross-sectional study in T1D patients without cardiovascular disease (CVD), with ≥ 1 of the following: ≥40 years-old, diabetic kidney disease, and/or T1D duration ≥ 10 years + cardiovascular risk factors.Preclinical atherosclerosis was evaluated by carotid ultrasonography.

Results: N = 584 patients were included (46.1 % women, age 48.7 ± 10.5 years, T1D duration 27.3 ± 10.8 years, 26.2 % active smokers). The overall plaque prevalence was 40.9 %. In models adjusted for age, sex, lipids, blood pressure, kidney function, statin use, microvascular complications and HbA, CTC was dose-dependently associated with the number of plaques (none, 1-2, ≥3) overall and in both active and former smokers (p < 0.001). This association remained after adjusting for ST1RE (OR 1.11 [1.02-1.19]). Although the inclusion of CTC in the ST1RE did not improve plaque identification overall (p = 0.180), it did so when analyzing active smokers separately (AUC 0.738 vs. 0.768; p < 0.01).

Conclusions: In T1D patients, CTC is dose-dependently associated with atherosclerosis. Further prospective studies are needed to determine if CTC could identify T1D individuals more prone to accelerated atherosclerosis.