Plasma fatty acid status in Moroccan children: increased lipid peroxidation and impaired polyunsaturated fatty acid metabolism in protein-calorie malnutrition

Abstract

In previous studies on plasma fatty acid and antioxidant status in 29 malnourished Moroccan children (12 with mild protein-calorie malnutrition, 17 with severe protein-calorie malnutrition) compared to 15 healthy control children from the same area, we pointed out that these populations were heterogeneous in terms of their essential fatty acid and antioxidant status. The aim of the present study was to classify the children using the Waterlow classification and their essential fatty acid status. The discrepancies in lipid parameters, nutritional and inflammatory markers, blood oxidative indexes, antioxidant micronutrients or trace elements (selenium, zinc, vitamin E) related to polyunsaturated fatty acids were checked in these populations. Eight of the control subjects and nine of the severe protein-calorie malnutrition children were essential fatty acid-deficient, compared to only one of the mild protein-calorie malnutrition group. Examination of the essential fatty acid-sufficient subjects with mild protein-calorie malnutrition, compared to the essential fatty acid-sufficient control subjects, showed only a decrease in Z scores and a non-significant decrease in selenium and vitamin E. In severely malnourished children, albumin, cholesterol and low density lipoprotein (LDL) cholesterol, plasma selenium, vitamin E and zinc were low, whereas inflammatory proteins and triglycerides were high. These features worsened with essential fatty acid deficiency. In all protein-calorie malnutrition subjects, there was oxidative stress (increase in thiobarbituric-acid reactants, imbalance between plasma polyunsaturated fatty acid, vitamin E and selenium levels), even in the absence of essential fatty acid deficiency. Monounsaturated fatty acids, oleic acid/stearic acid (C18:1 n-9/C18:0) Δ9 desaturase and n-3 and n-6 elongase activity indexes increased. The C18:1/C18:0 Δ9 desaturase activity index was negatively correlated to Z scores (r = –0.44, P < 0.01 for Z score weight, r = –0.39, P < 0.01 for Z score height), albumin (r = –0.82, P < 0.01) and zinc (r = –0.51, P < 0.01) levels. In essential fatty acid-deficient, severe protein-calorie malnutrition subjects, Δ6 desaturase activity was impaired, and there was a non-significant decrease in arachidonic acid. Essential fatty acid deficiency is a type of malnutrition, and is associated with an aggravation of all parameters in severe protein-calorie malnutrition. The increase in the C18:1/C18:0 Δ9 desaturase activity and enhanced lipid peroxidation without any essential fatty acid deficiency could be early markers of protein-calorie malnutrition.