Relationship between Serum Ghrelin and Suicidality in patients with Depression: A Systematic review and Meta-Analysis

Background Ghrelin, an orexigenic peptide hormone, mainly stimulates appetite and the release of growth hormone (GH). However, beyond its metabolic roles, Ghrelin has been implicated in the neurobiological pathways associated with mood regulation, suggesting a potential link between metabolic states and psychiatric conditions such as depression. The relationship between Ghrelin and suicidality, a severe and often terminal manifestation of psychiatric disorders remains under-explored. Aim To assess the relationship between serum Ghrelin and suicidality in patients with depression. Methods A systematic review and meta-analysis following PRISMA guideline was performed using PubMed, Medline, Embase, CINHL and Google Scholar in June, 2024. Two independent reviewers systematically evaluated the studies for inclusion and any disagreement was resolved by consulting a third reviewer. Meta analysis of the included studies was performed using MetaXL software version 5.3. The quality of the included studies was evaluated using the Newcastle-Ottawa Scale, and the risk of publication bias was assessed using a plotting funnel and Doi plots. Results Out of 249 studies identified through the database search, finally 3 studies were found eligible comprising of 302 participants. Pooling the results, the meta-analysis indicates an average increase (Effect size) of 106.01 units in serum Ghrelin levels among patients with suicidality over controls. This effect is statistically significant given the confidence interval range from 16.80 to 195.22. The heterogeneity across the studies was substantial, with an I² close to 99% and a Cochran's Q statistic of 198.77. The Funnel Plot revealed asymmetrical distribution of studies, particularly a shortage of smaller studies with negative or null outcomes. Conclusion Serum Ghrelin levels are found to be significantly elevated among individuals with suicidality compared to healthy controls. However, high heterogeneity across the studies limits the findings. Clinical Trial Number:- Not Applicable