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

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.