Common carotid artery (CCA) intima-media thickness (IMT) is increased independently of blood pressure and known determinants of wall thickness in confirmed prehypertensive subjects, recent findings suggest. Common carotid artery (CCA) intima-media thickness (IMT) is increased independently of blood pressure and known determinants of wall thickness in confirmed prehypertensive subjects, recent findings suggest. However, short-term CCA-IMT progression is not accelerated in this population.

"Previous studies have demonstrated that carotid IMT is increased already in subjects with borderline hypertension," Dr. Ele Ferrannini, from the Institute of Clinical Physiology in Pisa, Italy, and colleagues write in the October issue of Arteriosclerosis, Thrombosis, and Vascular Biology. "Whether carotid IMT is increased also in normotensive subjects that will develop hypertension (i.e., confirmed prehypertensives) has not been determined."

In their study, the researchers used B-mode ultrasound to measure CCA far-wall IMT in 1536 subjects from the population-based Mexico City Diabetes Study. The patients were examined at baseline and 3.5 years later.

A total of 136 normotensive subjects converted to hypertension between the first and second follow-up, for a crude rate of 2.4 per cent per year. Initially, CCA-IMT in the prehypertensive group (median 720 µm) was intermediate between normotensives and hypertensives (median 615 µm and 725 µm, respectively).

At the 3.5-year follow-up, CCA-IMT had increased by 35 µm. Significant predictors of CCA-IMT progression included gender, age, blood pressure, and presence of diabetes, but not converter status.

Furthermore, the investigators discovered that a polymorphism in the adiponectin gene was independently associated with increased CCA-IMT.