Author + information
- Harun Kılıç1,
- Enver Atalar2,
- İncilay Lay2,
- Nuray Yazihan3,
- Uğur Saygısunar4,
- Fatih Büyükçam4 and
- Ramazan Akdemir1
Low high-density lipoprotein (HDL) is prevalent in Turkey. HDL levels in Turkish population are 10-15 mg/dL lower than those of adults in the United States and Western Europa. Endothelial lipase (EL) regulates lipoprotein metabolism, mainly HDL metabolism. Decrease in the lipid content of HDL is thought to increase its capacity to remove cellular cholesterol; small, lipid-poor HDL particles thus represent more-efficient cholesterol acceptors than their large, lipid-rich counterparts. Aim of this study is to investigate HDL subfractions and effect of EL on HDL levels in healthy Turkish population.
A hundred two healthy subjects included to the study (Mean age 29,1+22 years, 42 female). Subjects who have secondary factors that can affect HDL metabolism excluded. HDL subfractions were assayed by combining a single precipitation method by heparin/Mn/Ds with a direct HDL assay. EL concentrations measured by competitive enzyme immunoassay (EIA) technique.
Mean HDL levels were 56,2+14,4 mg/dL in women, 42,5+11,7mg/dL in men. Small HDL concentrations did not differ statistically between <40 mg/dL, >40 and <60 mg/dL, and >60 mg/dL total HDL groups (Table 1). High HDL levels were mostly consisting of large HDL(Figure 1). Small HDL was not correlated with EL, total cholesterol, low density lipoprotein cholesterol (LDL), triglyceride (TG), age. Large HDL was positively correlated with EL (r=0.2, p=0.01), negatively correlated with age, LDL, TG (r=0.02, p=0.007, r=0.22, p=0.025, r=0.42, p<0.001) respectively. If subjects divided into 2 groups as HDL< 40 mg/dL and HDL> 40 mg/dL. EL levels are 25,79ng/mL and 30,77ng/mL respectively (p=0.004) (Figure 2).
There were no differences between small HDL concentrations in the HDL low and high groups. Low HDL concentrations may be functionally effective as high HDL concentrations. EL concentrations were positively correlated with HDL levels but EL primarily affects large HDL. Our results in healthy population may serve as a reference for clinical studies on HDL subfractions.
|Small HDL(HDL3)||Large HDL(HDL2)||Small/Large HDL Ratio|
p=0.074 for small HDL between HDL<39 and HDL > 60 groups p<0.0001 for large HDL between HDL<39 and HDL > 60 groups