Apolipoprotein C-III, metabolic syndrome, and risk of coronary artery disease

Chiara Stranieri,Oliviero Olivieri,Simonetta Friso,Domenico Girelli,Elisabetta Trabetti,Antonella Bassi,Nicola Martinelli,Pier Franco Pignatti,Francesca Pizzolo,Roberto Corrocher

doi:10.1194/jlr.m300253-jlr200

Abstract

Apolipoprotein C-III (apoC-III) is a marker of triglyceride (TG)-rich lipoproteins, which are often increased in metabolic syndrome (MS). The T-455C polymorphism in the insulin-responsive element of the APOC3 gene influences TG and apoC-III levels. To evaluate the contribution of apoC-III levels and T-455C polymorphisms in the coronary artery disease (CAD) risk of MS patients, we studied 873 patients, 549 with CAD and 251 with normal coronary arteries. Patients were classified also as having or not having MS (MS, n = 270; MS-free, n = 603). Lipids, insulin, apolipoprotein levels, and APOC3 T-455C genotypes were evaluated. ApoC-III levels were significantly increased in MS patients, and the probability of having MS was correlated with increasing quartiles of apoC-III levels. MS patients with CAD had significantly higher apoC-III levels than did CAD-free MS patients. The carriership for the -455C variant multiplied the probability of CAD in MS in an allele-specific way and was associated with increased apoC-III and TG levels. Obesity was less frequent in MS carriers of the -455C allele than in MS noncarriers (21.6% vs. 34.8%, P < 0.05). In conclusion, apoC-III-rich lipoprotein metabolism and the APOC3 polymorphism have relevant impacts on the CAD risk of MS patents.

Highlights

Apolipoprotein C-III is a marker of triglyceride (TG)-rich lipoproteins, which are often increased in metabolic syndrome (MS)
The results of the present study suggest that increased apoC-III levels are a common feature of the MS phenotype
ApoC-III levels were, significantly increased in the majority of MS patients, and the probability of having MS was directly correlated with apoC-III levels divided into quartiles (Fig. 1)

Summary

Introduction

Apolipoprotein C-III (apoC-III) is a marker of triglyceride (TG)-rich lipoproteins, which are often increased in metabolic syndrome (MS). In addition to the presence of hypertriglyceridemia and low serum HDL cholesterol, MS and/or insulin resistance are characterized by an increase of small LDL particles and triglyceride (TG)-rich lipoproteins, features that contribute to the cardiovascular disease risk [4,5,6,7,8]. (CAD) risk [3,4,5,6], is well recognized It is still unclear whether elevated levels of TG-rich lipoproteins and apoC-III are highly coexpressed in MS and what their specific contribution is to the higher risk for cardiovascular disease in MS patients

Methods

Results

Conclusion