The effects of n-3 PUFA on HDL metabolism has been studied in several randomized controlled trials, and the most of the studies suggest putative antiatherogenic changes, with increases of large HDL particles and/or decreases of small HDL particles. Nearly all studies have been LOUREIRIN-B conducted with fish oil supplements instead of fish consumption as part of the diet. It has also been shown that EPA and DHA supplementation improves reverse cholesterol transport from macrophage to feces in hamsters fed with high fat diet. Our findings of larger average diameter of HDL particles and increased concentration of large and extra-large HDL particles within the tertile with greatest increase in fish intake are consistent with earlier results. We also observed an association between changes in fish intake and changes in concentrations of total lipids, phospholipids, total cholesterol, cholesterol esters and free cholesterol in large HDL. However, based on this data we are not able to conclude if this reflects changes in the content of large HDL particles or only increased serum concentration of large HDL particles. ApoA-1 and total HDL concentrations did not change during the intervention, which may be related to the trend of a decrease in small HDL particles, that may compensate increases in larger particles. Modern genome-wide and Mendelian randomization studies have failed to show a causal link between total HDL cholesterol concentration and coronary artery disease, which might be related to the fact, that HDL is a heterogenous pool of subpopulations which differ in their structure and function. In atherosclerosis-related diseases, variations in subpopulation levels and functions are observed, supporting the general view that the concentration of large HDL particles is inversely associated while that of small HDL particles is positively associated with Pimozide cardiovascular disease. In addition, Gordon et al recently reported that the phospholipid content of large HDL subfractions showed a significant inverse correlation with the vascular stiffness assessed using pulse wave velocity. In addition to this arterial stiffness measurements, cholesterol efflux from human THP-1 macrophages has been shown to correlate with phospholipids and particle mass of HDL demonstrating that the phospholipid content of HDL is an important determinant of cholesterol efflux. Furthermore, the effect of HDL particle size on efflux capacity, and the impact of large HDL particles on cholesterol removal strongly suggest their protective role against the development of atherosclerosis. The association between hypertriglyceridemia and CVD risk is also controversial and is weakened when adjustment is made for other risk factors. Here we found cross-sectional negative correlations between serum Tg concentration and average diameter of HDL and LDL particles, a finding that is also evident in metabolic syndrome. This suggests that the known effect of serum Tg concentration on increased risk of CVD or type 2 diabetes may in part be related to altered HDL metabolism. The relationship between CETP and lipoprotein metabolism is complex. CETP is central in cholesterol and Tg transport between HDL and apoB-containing lipoproteins in the circulation, and this CETP-mediated lipid transfer clearly differs in various dyslipidemias. CETP simultaneously affects the concentration and composition of both antiatherogenic and atherogenic lipoproteins and its connection to coronary heart disease risk is not completely understood.