Effects of aging on serum levels of lipid molecular species as determined by lipidomics analysis in Japanese men and women

Background: Aging is known to be associated with increased risk of lipid disorders related to the development of type 2 diabetes. Recent evidence revealed that change of lipid molecule species in blood is associated with the risk of type 2 diabetes. However, changes in lipid molecular species induced by aging are still unknown. We assessed the effects of age on the serum levels of lipid molecular species as determined by lipidomics analysis. Methods: Serum samples were collected from ten elderly men (71.7 +/- 0.5 years old) and women (70.2 +/- 1.0 years old), ten young men (23.9 +/- 0.4 years old), and women (23.9 +/- 0.7 years old). Serum levels of lipid molecular species were determined by liquid chromatography mass spectrometry-based lipidomics analysis. Results: Our mass spectrometry analysis revealed increases in the levels of multiple triacylglycerol molecular species in the serum of elderly men and women. Moreover, serum levels of total ester-linked phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were increased by aging. In contrast, serum levels of specific ether-linked PC and PE molecular species were lower in elderly individuals than in young individuals. Conclusions: Our finding indicates that specific lipid molecular species, such as ether-and ester-linked phospholipids, may be selectively altered by aging.