Relationship Between Apolipoprotein AI,AII,Body Mass Index And Distribution Of Plasma HDL Subclasses

Part One Relationship between apolipoprotein concentrations and HDL subclasses distributionBackground: Alterations in plasma apolipoproteins levels can influence the composition, content, and distribution of plasma lipoproteins that affect the risk of atherosclerosis. This study assessed the relationship between plasma apolipoproteins levels, mainly apoAI, and HDL subclass distribution.Methods: The contents of plasma HDL subclasses were determined by 2-dimensional gel electrophoresis coupled with immunodetection in 545 Chinese subjects. We make use of the apoAI mean plus or minus 1 SD, So, the subjects were further subdivided into low apoAI group (apoAI≤1043.6mg/L), middle apoAI(1043.6＜apoAI＜1452.6) and high apoAI(apoAI≥1452.6mg/L) respectively.Results: Compared with low apoAI group, the contents of all HDL subclasses increased significantly both in middle and high apoAI group, and the contents of large-sized HDL_2b increased more significantly relative to those of small-sized preβ₁-HDL in high apoAI group. Meanwhile, when apoAI and HDL-C levels increased simultaneously, in comparison to low apoAI along with HDL-C concentration group, a significant increased (116%) was shown in HDL_2b but only a slight increase (26%) in preβ₁-HDL. In addition, Pearson correlation analysis revealed that apoAI levels were positively and significantly correlated with all HDL subclasses. Multiple liner regression presented the apoAI concentrations were the most powerful predictor for HDL subclasses distribution.Conclusion: With the elevation of apoAI concentrations, the contents of all HDL subclasses increased successively and significantly, especially, an increased in large-sized HDL2b. Further, when apoAI and HDL-C concentrations increased simultaneously, the shift to larger HDL size was more obvious. Which, in turn, indicated that HDL maturation might be enhanced and, the reverse cholesterol transport might be strengthened along with apoAI levels might be a more powerful factor to influence the distribution of HDL subclasses.Part Two The influence of apolipoproteinAII concentrations on HDL subclasses distributionBackground: To investigate the impact of plasma apoAâ…¡concentrations on the alteration of HDL subclasses distribution. And the cooperative effect of apoAâ… and apoAâ…¡on it.Methods: The contents of plasma HDL subclasses were quantities by two-dimensional gel electrophoresis associated with immunodetection in 292 Chinese subjects. These subjects were divided into low apoAII (apoAⅡ≤232.4mg/L), middle apoAâ…¡(232.4＜apoAⅡ＜331.2mg/L), high apoAII (apoAⅡ≥331.2mg/L) groups, low apoAâ… -Aâ…¡levels (apoAⅠ≤1024.2mg/L together with apoAⅡ≤232.4mg/L), middle apoAâ… -Aâ…¡levels (1024.2＜apoAⅠ＜1446.6mg/L together with 232.4＜apoAⅡ＜331.2mg/L) and high apoAâ… -Aâ…¢evels(apoAⅠ≥1446.6mg/L together with apoAⅡ≥331.2mg/L)groups according to the mean plus or minus 1 SD of apoAâ…¡or apoAâ… levels as two cut-points.Results: compared to the low apoAâ…¡group, the contents of HDLaa, HDLab, and HDL2b increased strikingly in high apoAâ…¡group. Moreover, the contents of all HDL subclasses increased progressively and significantly when apoAâ… and apoAâ…¡levels increased simultaneously, and in comparison to low apoAâ… -Aâ…¡levels group, the contents of large-sized nOL2b (115%)increased more significantly than those of small-sized preβ₁-HDL (39%) in high apoAâ… -Aâ…¡levels group. In addition, Pearson correlation along with multiple liner regression results revealed that apoAI was positively and significantly correlated with all HDL subclasses while apoAII only showed positive association with HDL_3a, HDL_3b and HDL_2b.Conclusion: excess apoAâ…¡can cause the accumulation of both large-sized HDL_2b and small-sized HDL₃. Which implied that apoAII play a double role in the HDL maturation metabolism. Meanwhile, large-sized HDL_2b increased significantly when apoAI and apoAâ…¡levels elevated simultaneously.Part Three Alterations of High Density Lipoprotein Subclasses in Obese SubjectsBackground: To investigate the characteristics of lipid metabolism in obese subjects, with particular emphasis on the alteration of HDL subclass contents and distribution.Methods: Apo-Aâ… contents of serum HDL subclasses were quantitated by two-dimensional gel electrophoresis in 581 Chinese individuals. According to the BMI which the Working Group on Obesity in China (W G O C) under the support of International life sciences focal point in China recommend criterion, the subjects were divided into four groups: underweight group(BMI＜18.5kg/m²),desirable group (BMI18.5-24kg/m²), overweight group (24＜BMI≤28kg/m²) and obesity group (BMI＞28kg/m²).Results: Concentrations of triglyceride, apoA-â… content of preβ₁-HDL were significantly higher (P＜0.01 and P＜0.01, respectively), but, the levels of HDL-C, apoA-â… contents of HDL_2a, HDL_2b were significantly lower (P＜0.01, P＜0.05 and P＜0.01, respectively) in obesity subjects versus desirable subjects. Moreover, with the elevation of BMI, small-sized preβ₁-HDL increased gradually and significantly, while large-sized HDL_2b decreased gradually and significantly in population. Meanwhile, the variations of HDL subclasses distribution above mentioned were more obvious with the elevation of TG levels in obesity along with overweight subjects. Pearson correlation analysis revealed that BMI, TG were positively correlated with preβ₁-HDL but negatively correlated with HDL_2b and multiple regression analysis also showed that TG concentrations were associated independently and positively with high pre_β1-HDL; while correlated independently and negatively with low HDL_2b in obesity along with overweight subjects.Conclusions: The particle size of HDL shifted toward smaller size in obesity and overweight subjects. Of note, the shift was more obvious with the elevation of BMI, especially TG levels. Which, in turn, indicated that HDL maturation might be abnormal, and reverse cholesterol transport might be weakened.