Objective: The purposes of this study were to compare plasma concentrations of circulating intercellular adhesion molecule 1 (cICAM-1), a marker of endothelial dysfunction, in nondiabetic subjects and type 1 diabetic patients and to evaluate whether chronic cigarette smoking had a deleterious effect on plasma cICAM-1 levels in type 1 diabetic patients.
Research design and methods: Plasma cICAM-1 concentrations were measured in 54 young type 1 diabetic patients without clinical macroangiopathy and in 20 healthy control subjects who were matched for age, sex, BMI, and smoking habit.
Results: Type 1 diabetic patients had significantly higher plasma levels of cICAM-1 than control subjects (280.4 +/- 59 vs. 224 +/- 53.6 ng/ml, respectively) (P < 0.001). After stratification by smoking status, diabetic smokers had values for age, sex, BMI, lipids, blood pressure, glycemic control, diabetes duration, and chronic complications of diabetes that were super-imposable on their nonsmoking counterparts. Nevertheless, plasma cICAM-1 levels were markedly elevated in type 1 diabetic smokers (321.4 +/- 64.2 vs. 257.3 +/- 41.5 ng/ml, respectively) (P < 0.001) in a dose-dependent fashion (P < 0.001 by analysis of variance when subjects were categorized by number of cigarettes smoked per day).
Conclusions: Chronic cigarette smoking has a deleterious effect on plasma cICAM-1 levels in young type 1 diabetic patients, which further supports the clinical importance of discouraging the initiation of smoking and promoting its cessation in people with type 1 diabetes.