Claude Nguyen, MD
Traditional Risk Factors are Not Major Contributors to the Variance in Carotid Intima-Media Thickness. Stroke. 2013
Carotid intima-media thickness (cIMT) is a marker for atherosclerosis and cardiovascular disease. Variations in cIMT, particularly in areas free of atherosclerosis, may suggest that non-traditional atherosclerotic risk factors may be at play. Rundek et al. sought to characterize the contribution of traditional and less traditional vascular risk factors toward cIMT. As a sub-project of the Northern Manhattan Study (NOMAS), 1790 healthy subjects received high-resolution 2D carotid ultrasounds to assess cIMT in areas free of plaque. Logistic regression was used to assess the relationship between stroke risk factors (traditional and nontraditional) and cIMT. The authors found that age, male sex, glucose, smoking by pack-years, and LDL levels explain only some of the variation observed in cIMT. Less traditional risk factors (homocysteine, GFR, and inflammatory markers) did not significantly contribute to cIMT variation, even after excluding subjects with known cardiovascular status (CAD, PAD, or MI). Based on their findings, the authors postulate that variations in cIMT may actually be due to the aging processes and does not indicate atherosclerotic risk.
The role in cIMT when characterizing atherosclerotic risk remains unclear, but underscores the importance of traditional risk factor control in stroke prevention. Control of traditional atherosclerotic risk factors has greatly contributed toward the reduction of stroke mortality over recent years. Yet, we have all observed patients who continue to have strokes despite control of these risk factors. Efforts like these to find ways to identify those at-risk by nontraditional risk factors may eventually lead to the emergence of other biomarkers as routine assessments for stroke risk.