INTRODUCTION: Serum insulin-like growth factor 1 (IGF-1), a hepatocyte-derived cytokine, has been suggested to reflect hepatic function reserve. The aim of this systematic review and meta-analysis was to investigate the association between serum IGF-1 levels upon the admission and prognosis of patients with advanced liver diseases. METHODS: A thorough examination of the literature was conducted across various databases, namely PubMed, Embase, Web of Science, Wanfang, and CNKI, with the aim of identifying relevant cohort studies. The data were synthesized using the random-effects model, taking into account the potential impact of heterogeneity. RESULTS: A total of nine cohorts were included. Patients with a low serum level of IGF-1, as compared to those with a high IGF-1 at baseline, exhibited a significantly poorer transplant-free survival (risk ratio [RR]: 3.03, 95% confidence interval: 2.17 to 4.22, p <
0.001), with no significant heterogeneity observed (p for Cochrane Q test = 0.92, I2 = 0%). A sensitivity analysis, which was conducted by excluding one study at a time, yielded consistent results (RR: 2.94 to 3.24, p all <
0.05). Additionally, consistent results were observed in further subgroup analyses based on various factors, including cutoffs of IGF-1, country of the study, patient diagnosis, methods for measuring serum IGF-1, follow-up duration, analytic model, and quality scores (p for subgroup difference all >
0.05). CONCLUSIONS: A diminished serum IGF-1 level upon admission could potentially serve as an indicator for an unfavorable prognosis among patients afflicted with advanced liver disease, such as severe hepatitis and cirrhosis.