Whole blood glycerophospholipids in dried blood spots − a reliable marker for the fatty acid status

Abstract

BackgroundWhole blood total fatty acid analysis in capillary blood has recently been proposed for fatty acid status determination, but the accuracy of this method is affected by the fast turnover of triaclyglyceride (TAG) fatty acids, the individual hematocrit and postprandial state. MethodAn established method for the glycerophospholipid (GPL) analysis in plasma was adapted for the analysis of whole blood GPL and tested in a fat challenge test. Blood samples were collected from nine participants after receiving a standardised breakfast containing 42g of sunflower oil. Whole blood GPL fatty acids were compared against whole blood total lipid, plasma TAG and phospholipid fatty acids. ResultsAll fatty acid concentrations in dried blood samples showed a coefficient of variation <5.7%. The fat challenge test induced a significant increase of TAG fatty acid concentration (mean Δ=42.3%±35.7) and whole blood total fatty acid concentration (mean Δ=5.2%±3.7) whereas whole blood GPL fatty acids were hardly changed (mean Δ=1.3%±1.6). ConclusionWhole blood GPL fatty acids are a robust biological marker for the fatty acid status of fasted and non-fasted subjects. The influence of very recent dietary intake on whole blood GPL is smaller than on whole blood total lipids.