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.