Soluble interleukin-2 receptor as a marker for progression of coronary artery calcification in type 1 diabetes

Abstract

Introduction Soluble interleukin-2 receptor (sIL2r), a marker of T cell activation, is elevated in inflammatory processes, such as rheumatoid arthritis, hepatitis and neoplasm. We explored a potential association between plasma sIL2r levels and progression of coronary artery calcification (CAC), a marker for subclinical atherosclerosis, in a prospectively followed cohort of type 1 diabetic and non-diabetic subjects, aged 20–59 years, with no history of coronary artery disease. Materials and methods CAC progression was assessed by electron beam tomography over 2.6 years (range 1.6–3.2). Plasma sIL2r levels were measured in a nested case–control substudy of 98 subjects (67 diabetic, 31 non-diabetic) with and 173 subjects (84 diabetic, 89 non-diabetic) without significant CAC progression. Log-transformed sIL2r levels were analyzed by conditional logistic regression to compare subjects with and without significant CAC progression. Results SIL2r was a significant predictor for CAC progression after adjusting for presence of baseline CAC, age, gender, diabetes status, baseline calcium volume score and adiponectin (OR 1.99, 95% CI 1.09–3.61, p = 0.02 for a doubling of sIL2r level). Addition of BMI, LDL, HDL, hypertension, smoking status, HbA1c, CRP, fibrinogen, homocysteine and PAI-1 to regression models weakened but did not remove sIL2r as a predictor of CAC progression. There was no indication that this effect was different by diabetes status ( p = 0.6 for diabetes–sIL2r interaction). Discussion Elevated plasma sIL2r is associated with CAC progression independent of traditional coronary artery disease risk factors in type 1 diabetic and non-diabetic young adults. SIL2r should be considered as a novel marker of inflammation leading to coronary artery disease.