【Abstract】 Objective To investigate the expression levels of microRNA-212 (miR-212) and silent information regulator 1 (SIRT1) in the serum of patients with pituitary growth hormone (GH) adenoma and their relationships with prognosis. Methods 58 patients with GH adenoma admitted to our hospital from January 2016 to August 2019 were selected for the study, and 62 healthy people who were examined in our hospital at the same time were selected for the control study. The expression levels of miR-212, SIRT1, hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were detected by realtime fluorescent quantitative PCR (qRT-PCR). The levels of serum miR-212, SIRT1, HIF-1α and VEGF in GH adenomas with different prognosis were compared. Pearson's method was used to analyze the correlations between the expression levels of miR-212, SIRT1 and HIF-1α, VEGF, and the relationship between the expressions of miR-212 and SIRT1. The diagnostic values of serum miR-212 and SIRT1 in the prognosis of GH adenoma patients were evaluated by receiver operating characteristic curve (ROC). Results The expression level of miR-212 in the patients with GH adenoma was significantly lower than that in the healthy group (t=7.434, P＜0.05), while the levels of SIRT1, HIF-1α and VEGF in serum were significantly higher than those in healthy group (P＜0.05). The expression level of miR-212 in the non remission group was significantly lower than that in the remission group (P＜0.05), while the expression levels of SIRT1, HIF-1α and VEGF in serum were significantly higher than those in the remission group (t=2.536, 3.242, 2.638, P＜0.05). The expression level of miR-212 was negatively correlated with the levels of HIF-1α, VEGF and SIRT1 in GH adenoma patients (P＜0.05), and the expression level of SIRT1 was positively correlated with HIF-1α and VEGF (P＜0.05). The areas under the curve (AUCs) of serum miR-212 and SIRT1 levels in the evaluation of poor prognosis of GH adenoma patients were 0.873 and 0.862, and the corresponding cutoff values were 0.52 and 1.94, respectively. The corresponding sensitivities were 81.3% and 75.0%, and the specificities were 88.1% and 85.7%, respectively. The AUC of the combination in the evaluation of GH adenoma was 0.938, and the sensitivity and specificity were 93.8% and 81.0%, respectively. Conclusion The expression of miR-212 in serum of GH pituitary adenoma is downregulated, and the expression of SIRT1 is upregulated. They may interact with HIF-1α and VEGF, and then cooperate with the occurrence and development of GH adenoma. miR-212 and SIRT1 are expected to be the reference indexes to evaluate the prognosis of GH pituitary adenomas. The combination of them can effectively improve the prognosis value of GH pituitary adenomas.