Evaluation of leptin levels in serum as a biomarker for suicide behavior: systematic review and meta-analysis

Objective: We conducted a meta-analysis of case-control studies to determine whether leptin levels in serum contribute to the pathogenesis of suicide behavior. Methods: PubMed, EBSCO and Science Direct databases were used to search for relevant articles published before January 2020. The systematic review included nine case-control studies that measured leptin levels. The standardized mean difference (d) and 95% confidence intervals were calculated in a fixed-effects model and a random-effects model when appropriate. Results: The results of our meta-analysis indicated that individuals with suicide behavior presented reduced levels of leptin (d: -1.80, 95% CI: -2.21 to -01.38 ng/ml, I-2 = 0, p(Q) = 0.59). Sensitivity and publication bias analyses confirmed these results. Conclusions: The current meta-analysis suggests that leptin levels might be associated with an increased risk of suicide behavior. However, more studies including larger sample sizes are needed to reach conclusive result.

Automated summary

The meta-analysis revealed that individuals with suicide behavior have lower levels of serum leptin. Further studies are needed to confirm this finding and establish the exact relationship between leptin levels and the increased risk of suicide behavior.