The association between C-reactive protein, Interleukin-6 and depression among older adults in the community: A systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational (cross-sectional and longitudinal cohort) studies
PubMed 29237576 · doi:10.1016/j.exger.2017.12.005
What was done
Authors searched five databases for studies investigating the association of C-reactive protein (CRP) and Interleukin-6 (IL-6) with depression among community-dwelling adults aged 50 and older. They identified 32 eligible studies (23 cross-sectional, 7 longitudinal, and 2 evaluating both) and synthesized them using random-effects meta-analysis to evaluate cross-sectional associations and longitudinal directionality.
What was found
The meta-analysis found cross-sectional and longitudinal associations between both CRP and IL-6 with depression in older adults. Longitudinal evidence indicated that elevated inflammation led to depression rather than depression leading to inflammation. No specific numerical values, effect estimates, or confidence intervals were reported in the abstract.
Why it matters
The findings synthesize evidence linking systemic inflammatory markers with depression in older adults, providing longitudinal evidence that systemic inflammation may act as a precursor to late-life depression.
Limits
The abstract reports no numerical effect sizes or confidence intervals. Substantial heterogeneity was observed across studies, driven by variations in confounder adjustment and differences in the methods used to measure both inflammation and depression. All underlying studies were observational.
Cited by
- supports Elevated C-reactive protein levels correlate with a higher incidence of depression.