Potential role of folate status on pulmonary function in pediatric asthma.

Objective: The aim of this study was to explore the relationship between plasma folate status and measures of airway disease (as reflected by spirometry) in children with asthma on a traditional Mediterranean diet. We hypothesized that folate deficiency is associated with lung function impairment in this group of children.

Methods: This cross-sectional study included 64 children with mild asthma (52% boys, mean age 8 ± 2 y) residing in Athens, Greece. Clinical assessments included spirometry and fractional exhaled nitric oxide (FeNO). Plasma 5-methyltetrahydrofolate (5-MTHF) was analyzed using high performance-liquid chromatography assay and examined in participants using quartiles (Q1-Q4).

Results: Of the 64 children, 45.3% were folate deficient (5-MTHF <10 nmol/L). A positive relationship was observed between 5-MTHF and forced vital capacity (FVC; β = 0.79, 95% confidence interval (CI), 0.14-1.44; adjusted P = 0.019), forced expiratory volume in 1s (FEV) (β = 0.78; 95% CI, 0.01-1.55; adjusted P = 0.046), and peak expiratory flow (PEF; β = 1.64; 95% CI, 0.14-3.15; adjusted P = 0.033) in girls only, adjusting for body mass index and regular exercise. Girls with low plasma folate concentrations (Q1), compared with girls with high concentrations (Q4) had 8.64% lower FVC (β = -8.64; 95% CI, -16.18 to -1.09; adjusted P = 0.027), 10.35% FEV (β = -10.35; 95% CI, -18.82 to -1.89; adjusted P = 0.019), and 18.72% PEF (β = -18.72; 95% CI, -36.30 to -1.14; adjusted P = 0.038).

Conclusion: The findings of this study highlighted the potential negative effects of folate deficiency on pulmonary function in girls with asthma, the importance of monitoring folate status in children with asthma, and early prevention strategies.