Polyunsaturated fatty acids and plasmalogens in diabetics

PurposePlasmalogens are phospholipids characterized by a vinyl ether bond and a preferential esterification of polyunsaturated fatty acids (PUFA). We have previously shown that the lack of plasmalogens leads to retinal hyper-capillarization. We hypothesize that plasmalogens are negative regulators of vascular development, and aimed to check their circulating levels in diabetic patients with a retinopathy. MethodsBlood samples were collected from 88 patients and 14 control subjects. Among diabetics we had 14 patients without diabetic retinopathy (DR), 12 with a mild non proliferative DR, 12 with a moderate non proliferative DR, 22 with a severe non proliferative DR and 24 with a proliferative DR (PDR). Erythrocytes were isolated from total blood samples. The plasmalogen content and the fatty acid composition of erythrocyte phospholipids were determined using capillary column gas chromatography. Individual species of phospholipids, including plasmalogens, were quantified by liquid chromatography coupled with a triple quadrupole mass spectrometry instrument (HPLC-ESI+MS/MS). ResultsGas chromatographic analyzes showed significant reduced levels of omega-3 PUFAs including docosahexaenoic acid (DHA) (p<0.01) and omega-6 (p=0.01) PUFAs including arachidonic acid in diabetics without DR and with DR at any stage vs controls. The ratio omega-6/omega-3 tended to increase to become significant in PDR patients vs controls (p=0.01). The analysis of individual species of phospholipids by HPLC-ESI+MS/MS showed reduced levels of choline-phospholipids esterified with DHA in PRD patients vs controls (p=0.02) and reduced levels of ethanolamine-phospholipids esterified with DHA at the mild, moderate, severe stages (p=0.03) vs controls. Levels of cholin and ethanolamine-plasmalogens remained stable in all the diabetics when compared to controls. ConclusionsThe changes observed for omega-3 and omega-6 PUFA between controls and diabetics deserve further studies.