Association between non‐high‐density lipoprotein cholesterol levels and the prevalence of asymptomatic extracranial internal carotid artery stenosis in a Chinese community‐based study

Association between cumulative exposure to different lipid parameters and risk of newly developed carotid plaque

Background and purpose

Both the magnitude and cumulative exposure of atherogenic lipoproteins have an impact on the atherosclerosis risk, and the exploration focus has shifted from one single lipoprotein assessment to the cumulative exposure of lipoproteins. We aim to investigate the relationship between cumulative exposure to different lipid parameters and the risk of newly developed carotid plaque in this study.

Methods

In the Asymptomatic Polyvascular Abnormalities Community study, 2947 participants were included with follow-up every 2 years from 2006 to 2012. Lipid parameters including total cholesterol (TC), triglycerides (TGs), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC) and non-HDLC were measured. Cumulative exposure was calculated by adding the weighted sum of the difference between the measured value and the cut-off value of each parameter. Newly developed carotid plaques were identified by carotid ultrasound performed at the third and fourth follow-ups.

Results

In the univariate analysis, non-HDLC burden had the highest ORs among the five lipid parameters for newly developed carotid plaque in each quartile, as 1.0 (reference), 1.35 (1.09–1.67), 1.68 (1.36–2.08) and 2.74 (2.22–3.38) from the lowest to the highest quartile. In the multivariate analysis and sensitivity analysis, we obtained similar results.

Conclusions

TC burden, TG burden, LDLC burden and non-HDLC burden are all independent risk factors for newly developed carotid plaque, especially for the vulnerable plaques. Among lipid parameters, non-HDLC burden is an optimal predictor. Moreover, the predictive value remained significant for participants under the age of 65 years old or free of hypertension, diabetes mellitus and hyperlipidaemia.

Association Between Cumulative Exposure to Increased Low-Density Lipoprotein Cholesterol and the Prevalence of Asymptomatic Intracranial Atherosclerotic Stenosis

Background and Purpose: Intracranial atherosclerosis has gained increasing attention due to the high risk of recurrent clinical or subclinical ischemic events, while the relationship between low-density lipoprotein cholesterol (LDL-C) measured at a single time point and intracranial atherosclerotic stenosis (ICAS) is inconsistent. This study aims to assess the association between cumulative exposure to increased LDL-C and the prevalence of asymptomatic ICAS.

Methods: The Asymptomatic Polyvascular Abnormalities Community study was investigated on the epidemiology of asymptomatic polyvascular abnormalities in Chinese adults. In this study, we included 4,523 participants with LDL-C measured at 3 examinations in 2006, 2008, and 2010. Cumulative exposure to increased LDL-C was calculated as following: LDL-C burden_2006−2008 = [(LDL-C₂₀₀₆-1.8) + (LDL-C₂₀₀₈-1.8)]/2 ^* time_2006−2008; LDL-C burden = LDL-C burden_2006−2008 + LDL-C burden_2008−2010. Transcranial doppler ultrasonography was performed in 2010 to detecting the ICAS.

Results: Of the 4,347 patients, 13.3% (580/4,347) were diagnosed with ICAS. In univariate analysis, the association between LDL-C burden and ICAS prevalence was significant, the odds ratios (95% confidence interval) from the lowest to the highest quartile were 1 (reference), 1.30 (0.99–1.70), 1.32 (1.01–1.73), and 2.14 (1.66–2.75), respectively (P < 0.05). After adjustment for potential confounding factors, the same result was reached.

Conclusions: Cumulative exposure to increased LDL-C is concentration-dependently associated with increased prevalence of asymptomatic ICAS, especially in those under the age of 65 y or free of hypertension, diabetes mellitus, and hyperlipidemia.

Treatment strategies for asymptomatic carotid artery stenosis in the era of lipid-lowering drugs: protocol for a systematic review and network meta-analysis

INTRODUCTION

Carotid endarterectomy (CEA), carotid artery stenting (CAS) and best medical therapy (BMT) are the major treatments used for significant asymptomatic carotid artery stenosis (ACAS, ≥50%). However, the widespread use of lipid-lowering drugs in this century has improved BMT outcomes. This study aims to compare the treatment efficacy of current BMT, CEA+BMT and CAS+BMT in patients with significant ACAS.

METHODS AND ANALYSIS

This protocol was designed based on the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Publication time for studies will be set from 1 January 2000 to 1 June 2020. We will search three databases: PubMed, EMBASE and The Cochrane Library. Suitable randomised controlled studies will be screened. The primary outcomes will include short-term and long-term mortality, stroke and myocardial infarction. OR and HR for dichotomous data and time-to-event data with 95% CIs will be calculated. Treatment effects among different therapies will be ranked according to the surface under the cumulative ranking curve and mean rank. A comprehensive evaluation of the risk of bias, heterogeneity and transitivity will be performed before data synthesis. Consistency and evidence quality will also be assessed.

ETHICS AND DISSEMINATION

There will be no need for ethics approval as this systematic review is a summary and analysis of existing literature. Final results may be presented in international conferences or a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019138942.