Type 1 diabetes leads to carotid artery stiffness in young adults

Type 1 diabetes can lead to internal carotid artery thickness and common carotid artery stiffness, and this effect is measurable by the time a person with diabetes reaches young adulthood, reported Elaine M Urbina, MD, Director of Preventive Cardiology at Cincinnati Children’s Hospital in Cincinnati, Ohio.
     The effect of diabetes on carotid intima-media thickness (cIMT) may be influenced by adiposity, but is independent of demographics, lipid levels, and blood pressure.
     “We need to control risk factors, especially obesity, in these adolescents and young adults to improve cardiovascular outcomes in type 1 diabetes,” Urbina said.
     She noted that increased cIMT is known to be an independent risk factor for adverse cardiovascular events and increases with age, and that adults with diabetes have more rapid cIMT progression than nondiabetics.
     She and colleagues conducted the SEARCH CVD trial, a substudy of the SEARCH (Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine) trial, to determine whether age and type 1 diabetes have an effect on cIMT in teens and young adults.
     Cases (127) included adolescents and young adults who had previously participated in SEARCH sites in Colorado and Ohio. Controls (35) were healthy, aged-matched people recruited from clinics at the 2 study sites.
     The mean age was 20 + 3 years (range 13–26). The median duration of diabetes was 10.1 + 3.9 years.
     The investigators used carotid ultrasound to determine maximal (systolic) and minimal (diastolic) lumen diameters to calculate stiffness equations using three different methods: Peterson, Young, and Incremental elastic moduli (PEM, YEM, and Einc, respectively).
     A comparison of covariates between cases and controls showed similar body mass index (BMI), systolic blood pressure, and lipid levels, but slightly yet significantly lower diastolic blood pressure in cases versus controls (mean 68.3 vs. 71.12 mmHg, P=.04).
     “This actually results in a slightly wider pulse pressure in cases, and wider pulse pressure may be an indication of increased arterial stiffness,” Urbina said.
     There was a trend toward more common carotid cIMT in cases versus controls (P=.08) and a significant difference in internal carotid cIMT (P=.026), and all three moduli showed significant differences in stiffness as well (PEM, P=.024; YEM, P=.026; Einc, P=.027).
     After adjustment for age, race, sex, mean arterial pressure, and lipid levels, the internal carotid cIMT remained significant (P=.05), but after additional adjustment for BMI, it was no longer significant (P=.10).
     In an analysis of arterial stiffness between cases and controls adjusted for age, race, sex, mean arterial pressure, lipid levels, and BMI, stiffness was significantly greater among diabetics older than 20 years (P<.04).