Relationship between erythrocyte phospholipid fatty acid composition and obesity in children and adolescents

Background Observational studies have reported inconsistent results on the association between circulating fatty acids and obesity. Objective The objective of this study was to investigate the relationship between erythrocyte phospholipid fatty acid composition and obesity in children and adolescents. Methods We conducted a case-control study including 1442 obese and 1442 normal-weight children and adolescents. Circulating fatty acid composition between cases and controls were compared both in the present study and literature-based meta-analysis. Individual fatty acids contributing most to discriminating cases and controls were identified by orthogonal partial least squares–discriminant analysis and their associations with obesity were explored by a conditional logistic regression model. Results Five saturated fatty acids (14:0, 16:0, 17:0, 18:0, 20:0) were higher, 9 polyunsaturated fatty acids (18:3n-3, 20:3n-3, 20:5n-3, 22:5n-3, 22:6n-3, 18:2n-6, 20:2n-6, 20:3n-6, 20:4n-6) were lower in cases than in controls, while pooled results from the comparative meta-analysis were only consistent in 22:5n-3, 22:6n-3 and 18:2n-6. The orthogonal partial least squares–discriminant analysis model indicated that 16:0, 18:0, 20:4n-6, and 22:6n-3 were the fatty acids contributing most to discriminating cases and controls. In the conditional logistic regression model, significant positive associations were found for 16:0 (per 1 SD OR = 1.43, 95% CI, 1.35–1.52) and 18:0 (per 1 SD OR = 1.12, 95% CI, 1.09–1.16), while significant inverse associations were found for 20:4n-6 (per 1 SD OR = 0.63, 95% CI, 0.58–0.69) and 22:6n-3 (per 1 SD OR = 0.56, 95% CI, 0.52–0.61). Conclusions Erythrocyte phospholipid 16:0 and 18:0 were positively and 20:4n-6 and 22:6n-3 were inversely associated with obesity in children and adolescents.