The Effects Of Age And Gender On The Function Of High-density Lipoprotein

Objective:To determine the effects of age and gender on the functions of the antioxidative,anti-inflammatory and promoting cholesterol efflux properties of high-density lipoprotein(HDL).Methods:1.We screened 60 males and females physical examinees who are from20 to 60(mean37.3 ±9.6)years old each,and males and females physical examinees who are from 60 to 78(mean68.7 ± 8.4)years old each.Exclusion criteria included any history of cardiovascular and cerebrovascular diseases,diabetes,liver and kidney disease.No subjects showed clinical signs of inflammation.Study subjects were free of lipid-lowering medication,estrogen replacement oral and anti-inflammatory drugs.2.Blood was sampled and lipids index was detected.The plasma samples were divided into youth group and elder group after HDL composition was collecting from the plasma by ultracentrifugation.(1)The inhibitory function of HDL on oxidation of low-density lipoprotein induced by Cu2+ was determined(MDA kits absorbance at523nm).(2)The anti-inflammatory effect and anti-apoptotic effect of HDL were detected.Human umbilical vein endothelial cells(HUVEC)were pretreated by HDL for 2 hours and then were injured by ox-LDL for 12 hours.The monocyte adhesion was observed with fluorescence microscope.The expressions of VCAM-1 and ICAM-1 were analyzed by western blot.(3)MTT and flowcytometry assay was used to detect the viability of the cells.(4)The macrophage cholesterol efflux rate which was mediated by HDL.Results:1.Compared with the youth group,the level of low-density lipoprotein,triglycerides and total cholesterol were higher in elder group and the male at the same age(P<0.05).The level of HDL of youth females were higher than males at the same age and that of elder group(P<0.05).2.The Anti-oxidative effect of HDL was lower in elder group than that in youth group,and the elder females were worse than elder males.The anti-inflammatory ability was reduced in elder group,however,there is no significant differences between males and females;The result of flowcytometry showed cell relative survival rate of youth group was higher than that of the elder group,and the difference was statistically significant(P<0.05).The results of MTT indicated that the cell vitality of young was higher than that of the elder group after HDL protection.The effect of promoting cholesterol efflux of HDL in elder group was lower than that of youth group,especially in elder female(P<0.05).Though the effect of promoting cholesterol efflux in elder male was also decreased,there is no significant difference when compared with youth group(P>0.05).ConclusionIncreasing age not only reduces the content of plasma high-density lipoprotein,but reduces the impact of its anti-oxidation,anti-inflammatory,anti-apoptotic and cholesterol efflux capacity.the antioxidant and efflux capacity of HDL in the elderly women was lower than that of the elderly men,while anti-inflammatory and anti apoptotic functions were not different.There is no differences in the function of HDL between young men and women.