Plasmalogens in human serum positively correlate with high-density lipoprotein and decrease with aging

Aim: The objective of the present study was to propose plasmalogens as a beneficial factor in human plasma by showing a highly positive correlation with high-density lipoprotein (HDL) and a significant reduction with aging. Methods: For 148 elderly subjects suspected of coronary artery disease (CAD), clinical characteristics such as coronary stenosis, hyperlipidemia, abnormal glucose tolerance, and hypertension were investigated, and serum biochemical markers including plasmalogens were determined. Results: Serum plasmalogens levels tended to fall in significant coronary stenosis and abnormal glucose tolerance. Correlative analyses among serum biochemical markers revealed that plasmalogens positively correlate with HDL-related values, particularly apolipoprotein A-I (apo A-I), and that the molar ratio of choline plasmalogen (ChoPlas) to ethanolamine plasmalogen (EtnPlas) correlates positively with low-density lipoprotein (LDL) particle size, and negatively with apo A-H and fasting triglyceride (TG) levels. Comparison of plasmalogens in elderly subjects with those of 119 healthy young subjects showed a marked decrease in serum plasmalogens levels by aging. Conclusion: These results suggest that serum plasmalogens, antioxidant phospholipids, function as a beneficial factor as well as HDL, and that the measurement of serum plasmalogens is useful in clinical diagnosis.