Alexander E. Merkler, MD 

Increased carotid-intima media thickness (cIMT) is associated with future cerebrovascular events. Although previous data has shown an inverse relationship between high density lipoprotein cholesterol (HDL-C) and future cerebrovascular events, this association has been challenged in recent trials; therefore, it is uncertain whether HDL-C subfractions have differential effects on cerebrovascular risk.

Using the Northern Manhattan Study (NOMAS), Dr. Tiozzo et al. evaluate the relationship between HDL-C subfractions and cIMT. NOMAS is a prospective cohort study designed to determine stroke incidence and risk factors in a multiethnic urban population in Manhattan.

Nine hundred eighty-eight stroke-free participants with available data on HDL-C subfractions and cIMT measurements using high-resolution ultrasound were evaluated. HDL-C was assessed as HDL2-C and HDL3-C subfractions, and total HDL. cIMT was calculated as the composite measure of the near and the far wall of IMT in the common, internal, and bifurcation of the carotid artery on both sides of the neck. After controlling for demographics, vascular risk factors, LDL, and triglyceride levels, both HDL2-C and total HDL-C were inversely associated with cIMT; the association was even more robust among patients with diabetes. No association was found between HDL3-C and cIMT.

The main limitation is the lack of temporality between HDL-C subfraction measurement and cIMT assessment.

Overall, the results suggest an inverse relationship between total HDL and HDL2-C and cIMT, but not between HDL3-C and cIMT. If confirmed, these results may lead to HDL subfraction targeted therapies to reduce the risk of cerebrovascular disease.