HbA1c Levels Predict Carotid IMT in Adolescents with Diabetes

Dr. Elaine M. Urbina, from the Cincinnati Children's Hospital Medical Center in Ohio stated that, "Now we have clear evidence in these adolescents that they're already developing target organ damage."

"This has been demonstrated in adults but this is really novel to demonstrate in such a young age group," Dr. Urbina added. "This is information that we need to use as physician advocates to really work with the legislature to improve reimbursement for obesity treatment."

In their published report, Dr. Urbina, Dr. Amy S. Shah and their colleagues note that most data on the evolution of atherosclerosis in young people is from autopsy studies. To learn more about the development of atherosclerosis in younger individuals and to identify risk factors, the researchers studied 129 patients of mixed ethnicity, ages 10 to 23, with Type 2 diabetes.

According to their report, 13.4% had an elevated common carotid IMT, 16.5% had increased bulb IMT, and 18.9% had elevated internal carotid IMT.

As HbA1c levels increased, the researchers found, so did study participants' carotid IMT. Duration of diabetes also was independently associated with carotid IMT.

For every 1% increase in HbA1c, the likelihood of having a thicker common carotid IMT increased by 35%, after adjustment for sex, systolic blood pressure z-score, and insulin use.

Furthermore, for every additional year of diabetes duration, the risk of a thicker bulb IMT rose by 33%, after adjustment for systolic blood pressure z score and HDL cholesterol, and the risk of a thicker internal carotid IMT rose by 29%, after controlling for sex, cholesterol levels and tumor necrosis factor alpha levels.

"These data suggest that poor glycemic control is associated with structural changes in the carotid artery that are consistent with early atherosclerosis," the researchers write.

Dr. Urbina wrote, "We suspect that these changes are reversible at this age.... There is evidence that thickening of the carotid artery wall in younger people consists of more fatty buildup and less calcification.... We suspect that these lesions are reversible, but we need more study."

J Clin Endocrinol Metab 2009;94:3740-3745.