Is There a Role for Fibrates in the Management of Dyslipidemia in the Metabolic Syndrome?

Does the addition of fibrates to statin therapy have a favorable risk to benefit ratio?

Statins effectively lower low-density lipoprotein cholesterol levels and the risk of cardiovascular disease (CVD) events, and because of this they have become a standard treatment for dyslipidemia and atheroprevention. Unfortunately, statin monotherapy may fail to normalize high triglycerides and low high-density lipoprotein cholesterol, and it prevents only a minority of CVD events. Further treatment of lipid disorders that remain after statin monotherapy should help reduce the residual CVD risk. Fibrate monotherapy lowers high triglyceride levels, raises low high-density lipoprotein cholesterol, and reduces CVD risk; therefore, fibrates are recommended as an adjunct to statins for treatment of residual dyslipidemia and residual CVD risk. This review provides an update on the benefits and risks of fibrate monotherapy and addresses the benefits and risks of adding fibrates to statins.

Association of common C-reactive protein (CRP) gene polymorphisms with baseline plasma CRP levels and fenofibrate response: the GOLDN study

OBJECTIVE

C-reactive protein (CRP) is an inflammatory marker that contributes to the prediction of cardiovascular disease. We investigated the influences of CRP polymorphisms on baseline CRP levels and fenofibrate-induced CRP changes in subjects with the metabolic syndrome.

RESEARCH DESIGN AND METHODS

We examined the association of CRP single nucleotide polymorphisms (SNPs) (m772A>G, m301G>A >T, i178T>A, 3u1273C>T, and 3u2131C>T) with baseline plasma CRP levels among 1,123 white U.S. participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study and the modulating effect of these SNPs on CRP response to a 3-week fenofibrate treatment among 290 participants with the metabolic syndrome.

RESULTS

There were strong associations of m301G>A>T (rs3091244; P = 0.003), i178T>A (rs1417938; P = 0.001), 3u1273C>T (rs1130864; P = 0.001), and 3u2131C>T (rs1205; P < 0.001) with baseline CRP levels. Moreover, among subjects with the metabolic syndrome, fenofibrate induced the greatest reduction in CRP levels for TT subjects of the i178T>A compared with TA and AA subjects (-30 for TT, -19 for TA, and -11% for AA; P = 0.004). Similarly, for the m301G>A>T, major allele carriers displayed maximal reduction of CRP over noncarriers (-20 for GG, -15 for GA and GT, and -0.3% for TA and AA; P = 0.020).

CONCLUSIONS

Our results demonstrate that common genetic variants within the CRP gene affect baseline CRP levels and further modulate CRP response in subjects with the metabolic syndrome treated with fenofibrate. This knowledge could contribute to a better prediction of therapeutic success.

Cholesterol efflux pathways and other potential mechanisms involved in the athero-protective effect of high density lipoproteins

Plasma high density lipoprotein (HDL) levels bear a strong independent inverse relationship with atherosclerotic cardiovascular disease. Although HDL has anti-oxidant, anti-inflammatory, vasodilating and anti-thrombotic properties, the central anti-atherogenic activity of HDL is likely to be its ability to remove cholesterol and oxysterols from macrophage foam cells, smooth muscle cells and endothelial cells in the arterial wall. To some extent, the pleotropic athero-protective properties of HDL may be related to its ability to promote sterol and oxysterol efflux from arterial wall cells, as well as to detoxify oxidized phospholipids. In cholesterol-loaded macrophages, activation of liver X receptors (LXRs) leads to increased expression of adenosine triphosphate (ATP) binding cassetter transporter (ABCA1), ATP binding cassetter transporter gene (ABCG1) and apoE and promotes cholesterol efflux. ABCA1 stimulates cholesterol efflux to lipid-poor apolipoproteins, whilst ABCG1 promotes efflux of cholesterol and oxysterols to HDL. Despite some recent setbacks in the clinical arena, there is still intense interest in therapeutically targeting HDL and macrophage cholesterol efflux pathways, via treatments with niacin, cholesterol ester transfer protein inhibitors, LXR activators and infusions of apoA-1, phospholipids and peptides.