Immune and cytokine dysregulation associated with low-grade inflammation in male adolescents

Abstract

Background: Low-grade inflammation (LGI) is a subclinical inflammatory state characterized by persistent, modest elevations in circulating inflammatory mediators and has been linked to later cardiometabolic risk. Data describing adolescent inflammatory profiles in Middle Eastern populations remain limited. Purpose: To evaluate the immune and cytokine profile associated with LGI in Iraqi school-aged male adolescents. Methods: This cross-sectional analytical study included 80 male adolescents aged 15-18 years recruited from secondary schools in Baghdad, Iraq, between March and August 2025. Participants were stratified by age and school and were operationally classified into an LGI group (n=15; hs-CRP ≥ 3.0 mg/L) and a control group (n=65). Inflammatory markers were measured using commercial ELISA kits (Elabscience Biotechnology Co., Ltd., Wuhan, China) and an immunoturbidimetric assay. Findings: Adolescents in the LGI group had higher hs-CRP (5.13 ± 1.11 vs. 0.57 ± 0.18 mg/L), IL-6 (6.17 ± 1.19 vs. 1.34 ± 0.31 pg/mL), TNF- α (12.84 ± 2.16 vs. 8.37 ± 1.24 pg/mL), and NLR (3.36 ± 0.49 vs. 1.72 ± 0.21), while IL-10 was lower (2.10 ± 0.34 vs. 5.09 ± 0.49 pg/mL; p<0.001). Standardized effect sizes were large across all markers (Cohen’s d: 1.8-2.9). Conclusion: In this sample, LGI was associated with a consistent pro-inflammatory profile marked by higher pro-inflammatory mediators, higher NLR, and lower IL-10. These findings support further longitudinal evaluation and targeted prevention strategies in adolescents with cardiometabolic risk factors.