Exploratory Analysis of Inflammatory Biomarkers and Their Association with Psychological Burden in Mexican Informal Caregivers: A Cross-Sectional Study in the Emergency Department

This cross-sectional exploratory study aimed to explore the association between inflammatory biomarkers and multidimensional psychological burden in informal primary caregivers of dependent older adults in an emergency department. We included 78 caregivers and up to 89 controls. Multidimensional psychological burden (perceived stress, depression, anxiety, and caregiver burden) was assessed using standardized instruments. Morning serum levels of cortisol, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive Protein, were measured. Statistical analyses included between-group comparisons (Mann–Whitney U test), correlations (Spearman rank correlation coefficient), and hierarchical block regression adjusted for obesity, diabetes, and hypertension in the caregiver group. Multiplicity was addressed using the False Discovery Rate (FDR) procedure, and the findings were validated through 1000 bootstrap resamples. Caregivers had significantly higher levels of TNF-α compared to controls (p = 0.021), a finding confirmed by bootstrap analysis (95% CI: −2.6730 to −0.2940). IL-6 levels were positively correlated with trait anxiety (p = 0.007) and caregiver burden (p = 0.019). Comorbidity-adjusted hierarchical regression confirmed significant associations between IL-6 levels and trait anxiety and caregiver burden (ΔR2 = 0.123, p = 0.007), although these associations did not remain significant after adjustment for FDR. Caregivers showed elevated levels of TNF-α and exploratory associations between IL-6, trait anxiety, and caregiver burden, justifying confirmation in studies with a larger number of participants.