Association of CBC-derived inflammatory biomarkers with overall anemia in U.S. youth: NHANES study

Evidence suggests a link between inflammation and anemia. This study investigates potential associations between novel inflammatory biomarkers and anemia. Data were obtained from 11,564 participants aged ≤ 18 years from NHANES 2005-2018. Six indices were evaluated: systemic immune-inflammation index (SII), pan-immune-inflammation value (PIV), systemic inflammation response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). Logistic regression, subgroup, and sensitivity analyses were performed. Among 11,564 children (mean age 11.8 ± 3.8 years, 51.2% male), 571 cases of anemia were identified. After full adjustment, higher levels of SII, PIV, PLR, and MLR remained significantly associated with increased odds of anemia, whereas the associations for SIRI and NLR were attenuated and no longer statistically significant (both P > 0.05). Compared with the lowest quartile, the highest quartile was associated with greater odds of anemia for SII (OR = 1.65, 95% Cl 1.14-2.38), PlV (OR = 1.64, 95% CI 1.17-2.30), PLR (OR = 1.70, 95% CI 1.19-2.43), and MLR (OR = 1.63, 95% Cl 1.19-2.23). Restricted cubic spline analyses indicated linear associations between all six CBC-derived markers and anemia. Sensitivity stratified analyses showed significant interactions for SII (race, P = 0.03), PIV (age, P = 0.01; sex, P = 0.04), and NLR, whereas MLR, PLR, and SIRI demonstrated consistent associations across subgroups. These results suggest that CBC-derived inflammatory indices are independently associated with overall anemia prevalence in children and adolescents, highlighting their potential as accessible markers for risk stratification.