Subclasses of serum HDL in middle and old aged patients with hyperlipidemia in Chengdu City

AIM: To detect the change of composition and ratio of serum HDL subclasses and explore the relationship between these changes and the plasma lipid level in patients with hyperlipidemia. METHODS: The components of subclasses of serum HDL in 172 middle and old aged patients with hyperlipidemia and 115 healthy middle and old aged were determined by dimensional gel electrophoresis associated with immuno-blotting method. RESULTS: Compared to the healthy controls, the contents of pre β1-HDL，　HDL3b and HDL3a were significantly higher (P＜0.05 or P＜0.01), while that of HDL2b was significantly lower (P＜0.01) in middle and old aged patients with hyperlipidemia. The content of pre β1-HDL increased with age in healthy controls, whereas the HDL2b decreased. The content of pre β1-HDL was significantly higher (P＜0.05), while the HDL2b (P＜0.05) was significantly lower in men than in women in patients with hyperlipidemia and the healthy controls. In middle and old aged patients with hyperlipidemia, the content of pre β1-HDL was positively correlated with the serum TG, TC, apoB100, apoCⅡ, apoCⅢ, apoE and TG/HDL-C (r=0.432; r=0.243; r=0.341; r=0.259; r=0.335; r=0.308 and r=0.453, P＜0.05 or P＜0.01), while it was negatively correlated with HDL-C (r=－0.167, P＜0.05). The content of HDL2b was negatively correlated with TG, TC, apoCⅡ, apoCⅢ and TG/HDL-C (r=－0.296; r=－0.156; r=－0.182; r=－0.216; r=－0.203 and r=－0.313, P＜0.05 or P＜0.01), while it was positively correlated with HDL-C (r=0.124, P＜0.05). CONCLUSIONS: The particle of HDL in the middle and old aged patients with hyperlipidemia showed a general shift towards smaller size, which indicated that the reverse cholesterol transport might be weakened. Men had smaller HDL particle size than women.