Features of omega-3/omega-6 fatty acid metabolism in children with epileptic encephalopathies and autism spectrum disorders

Abstract

Purpose - to study the level of the serum fatty acids in children with autism spectrum disorders (ASD); to compare omega-6/omega-3 ratio depending of the clinical manifestation epileptic encephalopathy (EE) and ASD and electroencephalography data (EEG). Materials and methods. The study examined 101 children aged 2-6 years (mean age 4.02±0.95 years) with clinical manifestations ASD, who had been treated in a neuropsychiatric unit of the SI «Institute of Pediatrics, Obstetrics and Gynecology named after academician O.M. Lukyanova of the NAMS of Ukraine». According to the clinical features of epileptic encephalopathies and ASD, EEG monitoring data formed three groups: the group 1 - 35 children with clinical manifestations of ASD but without epileptic seizures and epileptiform changes in the EEG; the group 2 - 32 children with cognitive disintegration, clinical manifestations of ASD in which parents and health professionals did not note or noted a single history of epileptic seizures, but with epileptiform changes in the EEG; the group 3 - 34 children with clinical manifestations of ASD in which parents or health professionals have noted epileptic seizures and epileptiform changes in the EEG. In all children the level of blood fatty acids was determined by gas-liquid chromatography. Results. Indicators of fatty acid concentration indicate that the serum of children showed a significantly low level of omega-3 polyunsaturated fatty acids (PUFA) and saturation of omega-6 po PUFA in all groups of children. The level of concentration of the main metabolites of essential fatty acids reflects the imbalance due to deficiency of essential linolenic acid and its metabolite - docosapentaenoic acid, especially in children with ASD and epileptiform changes in the EEG (group 2), (p<0.01). Among the omega-6 PUFA found a high content of essential linoleic acid and its metabolite - arachidonic acid, which causes the total excess of this group of PUFA, more pronounced in the groups 1 and 2. The level of index of unsaturated fatty acids in children from the group 1 was 10.1, in children from the group 2 - 9.8, and in the group 3 - 9.3. The obtained results of the assessment of the unsaturation index reflect the lower level of index of unsaturated fatty acids in children of the group 3 who have manifestations of ASD and epileptic seizures compared to other groups (p<0.05, r=0.99). Conclusions. The data is a reliable evidence that children with ASD, epileptic seizures and epileptiform changes in the EEG have higher levels of omega-6 PUFA and arachidonic acid and omega-3 and docosahexaenoic acid deficiency. The most pronounced imbalance in both the ratio of omega-6 / omega-3 and arachidonic acid / docosahexaenoic acid in the group of children with ASD and epileptiform changes in the EEG. These results may support the theory of changes in the properties of the phospholipid membrane and ion channels of nerve cells and require further study using electron microscopy. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of all participating institutions. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors. Keywords: autism spectrum disorders, epileptic seizures, essential fatty acids, monounsaturated fatty acids, unsaturated fatty acids, fatty acid unsaturation index.