Carotid Intima-Media Thickness: An Index for Subclinical Atherosclerosis in Type 1 Diabetes

Abstract

Cardiovascular disease and the development of coronary artery atherosclerosis play a pivotal role in increasing mortality in patients with diabetes. The aim of the present study was to determine the presence of subclinical atherosclerosis (measured as carotid intima-media thickness [cIMT] and to study possible associated risk factors in adolescents with type 1 diabetes. Forty type 1 diabetic subjects, aged 11–30 years, with duration of diabetes 3–25 years and 40 normal healthy controls, were included. Blood pressure (BP) measurement, as well as screening for diabetic complications, was performed. Lipid profile, albumin/creatinine ratio, renal functions and glycosylated hemoglobin (HB A₁c) were assayed. Carotid intima-media thickness (cIMT) was measured using ultrasound. The mean aggregate cIMT was higher in diabetics than controls (0.6 mm 00 ± 0.1 vs. 0.4 mm ± 0.1, p = 0.000). Moreover, it was higher in patients with positive family history of type 2 diabetes than in those with negative family history (mean 0.7 mm ± 0.1 vs. 0.6 mm ± 0.1, p = 0.018). cIMT was found to positively correlate with: age in both diabetics and controls (r = 0.76, p = 0.000, r = 0.74, p = 0.000 respectively), body mass index (BMI) in diabetics but not controls (r = 0.82, p = 0.000, r = 0.30, p = 0.06 respectively). In diabetics, mean aggregate cIMT positively correlated with duration of diabetes (r = 0.66, p = 0.000), systolic blood pressure (r = 0.82, p = 0.000), diastolic BP (r = 0.83, p = 0.000), as well as HB A₁c (r = 0.40, p = 0.004) and correlated negatively with high density lipoprotein -cholesterol (HDL-C) (r = −0.88, p = 0.000). As cardiovascular morbidity is high in diabetes, non-invasive methods for monitoring vascular changes as cIMT might be useful in clinical practice for early diagnosis of subclinical atherosclerosis, which can allow for strategies designed to reduce the cardiovascular event rate in those patients.