Serum LDL-C/HDL-C ratio and the risk of carotid plaques: a longitudinal study

Dyslipidemia contributes to an increased risk of carotid atherosclerosis. However, the association between the ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol (HDL-C) and carotid plaque formation has not been well documented. This study aims to assess the role of LDL-C/HDL-C in the risk of carotid plaque formation in a Chinese population.

We followed 2,191 participants who attended the annual routine health examination. Cox proportional hazards regression, restricted cubic spline (RCS), and subgroup analysis were applied to evaluate the association between the LDL-C/HDL-C ratio and carotid plaques. The hazard ratio (HR) and 95% confidence interval (CI) were used to estimate the strength of the association.

Among 2,191 participants, 388 had incident carotid plaques detected, with a median follow-up time of 1.05 years. Compared with subjects younger than 45 years, those aged 45 to 59 years (HR: 2.00, 95% CI: 1.55-2.58) and over 60 years (HR: 3.36, 95% CI: 2.47-4.58) had an increased risk of carotid plaque formation. Males (HR: 1.26, 95% CI: 1.01-1.56), diabetes (HR: 1.46, 95% CI: 1.06-2.01) and a high LDL-C/HDL-C ratio (HR: 1.22, 95% CI: 1.07-1.38) were significantly linked with the occurrence of carotid plaques. After adjusting for potential confounding factors, we observed that a high LDL-C/HDL-C ratio promoted carotid plaque events (HR: 1.30, 95% CI: 1.12-1.50). The RCS analysis revealed a significant nonlinear association. The association was stronger among females (P-interaction < 0.05).

A high LDL-C/HDL-C ratio could accelerate the occurrence of carotid plaques. Older men with diabetes and dyslipidemia are the critical target population. Women may be more likely to benefit from lipid-lowering interventions and thus avoid carotid plaque formation.