Relationship between serum albumin and blood eosinophils in adolescents with allergic triad

While the association between serum albumin and eosinophils has been investigated in adult asthma, its role in any pediatric atopic triad – asthma, allergic rhinitis, or atopic dermatitis – remains unclear. We assessed the association between serum albumin and blood eosinophil counts in adolescents presenting with any atopic triad, using data from a 2-year National Health and Nutrition Examination Survey (NHANES) cycle. We analyzed data from 658 participants aged 12–18 years with any atopic triad condition from the 2005–2006 NHANES cycle. Multivariate linear regression models were employed to assess the potential association between serum albumin levels and blood eosinophil counts (BEOC). Trend tests, smooth curve fitting, and threshold effect models were applied to confirm this relationship, and stratified analyses were conducted to assess its consistency across subgroups. A significant negative association was observed between serum albumin and BEOC in the fully adjusted model (β = −0.08 × 10 3 cells/µL, 95% CI: −0.15, −0.01, P  = .018). Moreover, curve fitting and threshold effect analyses confirmed a nonlinear relationship between serum albumin and BEOC, with an inflection point for threshold and saturation effects of 4.4 g/dL, beyond which the association attenuated. Stratified analyses confirmed robustness across key subpopulations. Our study identified a nonlinear association between serum albumin levels and BEOC in adolescents with any atopic triad, exhibiting an L-shaped relationship. These findings highlight albumin as a potential biomarker for nutritional-immunological interplay in allergic inflammation and support targeted nutritional strategies in at-risk pediatric populations.