Objective To investigate the mediating effect of cancerous fatigue between sleep and cognitive function in patients after gastrointestinal tumor surgery.

Methods A total of 314 patients with gastrointestinal cancer were selected as study objects. Cancer-related Fatigue Scale, Pittsburgh Sleep Quality Index Scale and Cancer Treatment Function Evaluation-Cognitive Function Scale were used to evaluate the patients′ cancer-related fatigue score, sleep score and cognitive function score, respectively. Pearson correlation analysis was used to explore the relationships among cancer-induced fatigue, sleep and cognitive function, and maximum likelihood method was used to build a structural equation model and verify it, and the mediating effect of cancer-induced fatigue on sleep and cognitive function were analyzed.

Results The score of cancer fatigue, sleep score and cognitive function score were (10.07±6.69), (7.46±3.99) and (97.13±25.40), respectively. Correlation analysis showed that cancer fatigue score was positively correlated with sleep score (r=0.308, P < 0.001), was negatively correlated with cognitive function score (r=-0.432, P < 0.001). Sleep score was negatively correlated with cognitive function score (r=-0.269, P < 0.001). The results of the mediating effect test showed that cancer-related fatigue had a partial mediating effect between sleep and cognitive function (explanatory variance ratio was 22.44%).

Conclusion There are close relationships among cancerous fatigue, cognitive function and sleep, and sleep can directly or indirectly affect cognitive function through cancer-related fatigue. Medical staff should pay attention to sleep and fatigue in patients with gastrointestinal tumor to reduce the incidence of cognitive impairment.