Smith · Neuroscience and biobehavioral reviews 2020 · systematic review and meta-analysis · n=30 studies

The association between loneliness, social isolation and inflammation: A systematic review and meta-analysis.

Cited 321 times in the scientific literature.

Level 3 - non-randomized controlled study

Systematic review and meta-analysis of observational studies

PubMed 32092313 · doi:10.1016/j.neubiorev.2020.02.002 · record verified 2026-08-27

What was done

A systematic review and random-effects meta-analysis evaluated the associations between loneliness, social isolation, and systemic inflammation in adults aged 16 or older from the general population. From 7,400 screened articles, 14 studies on loneliness and 16 studies on social isolation were included. Analyses examined associations with C-reactive protein, fibrinogen, and Interleukin-6 across least-adjusted and most-adjusted models.

What was found

The abstract reports directional results without point estimates, confidence intervals, or p-values. Loneliness showed no association with C-reactive protein or fibrinogen, but had a significant association with Interleukin-6 in most-adjusted analyses. Social isolation showed a significant association with C-reactive protein and fibrinogen in least-adjusted analyses, which remained significant only for fibrinogen in most-adjusted analyses. Social isolation was not associated with Interleukin-6.

Why it matters

The findings suggest that loneliness and social isolation may relate differently to specific inflammatory markers rather than driving a uniform systemic inflammatory profile.

Limits

The abstract does not provide exact numerical effect sizes, precision metrics, or total participant sample sizes. The underlying evidence base is observational, characterized by variable study quality, and limited by substantial methodological heterogeneity that impacted sensitivity analyses.

Cited by