Association Between Inflammatory BioDisease Sevmarkers and erity inPatients with Chronic Medical Conditions: A Cross-Sectional Studyfrom a Tertiary Care Hospital in South India

Abstract

Background: Chronic medical conditions are increasingly recognized as states of persistent low-grade systemic
inflammation, with biomarkers such as C-reactive protein (CRP), interleukin-6 (IL-6), and ferritin implicated in disease progression
and severity. Data from Indian tertiary care settings, particularly from South India, remain limited. Objective: To evaluate the
association between circulating levels of CRP, IL-6, and ferritin and clinical indices of disease severity in patients with selected
chronic medical conditions (type 2 diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, and
rheumatoid arthritis).
Methods: A cross-sectional observational study was conducted over seven months (November 2021 to May 2022) in a tertiary care
hospital in South India. Thirty adult patients with established chronic medical conditions were recruited. Severity was graded using
condition-specific validated tools. Serum CRP, IL-6, and ferritin were measured by standardized immunoassays. Associations were
tested using Spearman’s correlation and multivariable linear regression.
Results: Median (IQR) biomarker levels were CRP 8.4 (4.1–18.2) mg/L, IL-6 18.5 (9.2–42.7) pg/mL, and ferritin 186 (98–312)
ng/mL. All three biomarkers correlated positively with severity scores (CRP: ρ = 0.68, p < 0.001; IL-6: ρ = 0.74, p < 0.001; ferritin:
ρ = 0.52, p = 0.003). In adjusted analysis, IL-6 remained independently associated with severity (β = 0.41, p = 0.006). Conclusion:
Inflammatory biomarkers, particularly IL-6, are significantly associated with disease severity across diverse chronic medical
conditions in this South Indian cohort. These markers may aid in severity stratification, though larger longitudinal studies are
warranted.