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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12872-022-02942-w.