Carotid intima-media thickness in hyperlipidemic type I and type II diabetic patients

Ultrasonographic measurements of the combined thickness of the carotid intima and media can be used to examine early vessel wall changes in atherosclerosis. Premature atherosclerosis is common in diabetes, especially when other risk factors are present. Intima-media thickness was quantified in hyperlipidemic type I and type II diabetic patients, and relationships between various risk factors and intima-media thickness were investigated.

Thirty-one patients with type I diabetes and 56 with type II diabetes were examined, with an LDL cholesterol of > 2.6 mmol/l and/or triglycerides of > 1.7 mmol/l and/or HDL cholesterol of < 0.9 mmol/l for men or < 1.1 mmol/l for women. Intima-media thickness was measured on-line, over a length of 1 cm in the common carotid artery. Later, the mean and the maximum of six measurements was calculated (left and right side, both in three directions).

Mean intima-media thickness was 0.63 +/- 0.18 (+/-SD) mm for type I diabetes and 0.80 +/- 0.31 mm for type II diabetes. Adjusted for age, the difference was 0.06 mm, with a 95% CI of -0.08 to 0.20 mm. In multivariate regression analysis, age over 50 years and higher HbA1c were independently associated with an increase in mean intima-media thickness in type I diabetes. In type II diabetes, none of the variables reached a significance level of < or = 0.10. Results for maximum intima-media thickness were essentially the same.

In general, intima-media thickness is larger in type II diabetes than in type I diabetes. The effect of age is absent in type II diabetes, whereas in type I diabetes, age and blood glucose control have an important effect on intima-media thickness.