Meta-analysis on inflammation and autonomic nervous system of coronary heart disease combined with depression

Objectives This meta-analysis aimed to explore the association between inflammatory factors, heart rate variability (HRV) and the coexistence of coronary heart disease (CHD) and depression.Design Systematic review and meta-analysis. Complying with the Meta-analysis Of Observational Studies in Epidemiology statement.Data sources We searched PubMed, Web of Science and EMBASE for the data from the inception date to 16 March 2023.Eligibility criteria We included cross-sectional and cohort studies with inclusion criteria: (1) patients with CHD; (2) depression measurement and (3) including inflammatory factors or cardiac biomarkers or HRV.Data extraction and synthesis Two authors searched the databases independently. The effect estimates and heterogeneity were synthesised by Review Manager V.5.3. Sensitivity analysis and publication bias were analysed by STATA software. The quantitative synthesis outcomes were presented by mean difference (MD) or standard MD (SMD) with 95% CI.Results By searching the databases, we identified a total of 6750 articles. There were 22 articles left after selection, including 6344 participants. This meta-analysis indicated that patients with CHD with depression had higher levels of C reaction protein (CRP) (SMD 0.50, 95% CI (0.19 to 0.81), p=0.001), high-sensitivity C reactive protein (hs-CRP) (SMD 0.28, 95% CI (0.07 to 0.48), p=0.008), IL-6 (SMD 0.49, 95% CI (0.05 to 0.92), p=0.03) and a lower level of the mean RR interval and the SD of all RR intervals (SMD −0.64, 95% CI (−1.11 to –0.17), p=0.008), SD of the 5 min averages of all normal RR intervals (MD −12.77 ms, 95% CI (–21.20 to –4.33), p=0.003), overage of the SD of all normal RR intervals for each 5 min segment (MD −13.83 ms, 95% CI (–15.94 to –11.72), p50 ms (pNN50) (SMD −0.86, 95% CI (−1.41 to –0.31), p=0.002), than those without depression.Conclusions This study underscores the association between elevated CRP, hs-CRP, IL-6 and lower HRV in patients with CHD with depression. It emphasises the importance of clinicians assessing CRP, hs-CRP, IL-6 and HRV in patients with CHD to potentially identify depressive conditions.