Peripheral IGF-1 in bipolar disorder and major depressive disorder: a systematic review and meta-analysis.

BACKGROUND In recent years, a number of studies have shown abnormal levels of peripheral insulin growth factor-1 (IGF-1) in patients with mood disorder, but the results are not uniform. Therefore, this paper focuses on such studies, conducts a systematic review and meta-analysis, and discusses the factors affecting peripheral IGF-1 in patients with mood disorder. METHODS Cochrane database, PubMed database, Embase database, CNKI database, Wanfang Database and Weipu database were searched by computer. The retrieval time was from June 2020 to search for a controlled study of the relationship between bipolar disorder (BD) or major depressive disorder and normal control peripheral IGF-1. Review Manager (version 5.3) software was used for meta-analysis. RESULTS A total of 14 articles in Chinese and English were included; 285 patients with BD and 503 patients with major depressive disorder. Meta-analysis showed that in comparison with the control group, IGF-1 levels in peripheral blood of patients with BD (MD =67.66, 95% CI: 7.01-128.31, P=0.03) and major depressive disorder (MD =8.01, 95% CI: 3.43-12.58, P=0.0006) were significantly increased. In the meta-analysis comparing the peripheral IGF-1 levels of patients before and after treatment, the results showed no significant change in the peripheral IGF-1 level before and after treatment (P=0.53). CONCLUSIONS High peripheral IGF-1 level is a related factor of BD and major depressive disorder, although this needs to be confirmed by further large sample studies.