Association between preoperative sleep disturbance and low muscle mass in patients with gastrointestinal cancer.

[Purpose] Low muscle mass and sleep disturbance are common among geriatric patients with cancer. In patients with gastrointestinal cancer, low muscle mass is considered an indicator of poor prognosis. In the recent years, sleep disturbance has attracted much attention as a factor for low muscle mass among community-dwelling elderly individuals; however, such associations are unclear in patients with cancer. The present study investigated the relationship between preoperative sleep disturbance and low muscle mass in patients with gastrointestinal cancer. [Participants and Methods] This cross-sectional survey enrolled 86 elderly patients (aged more than 60 years) with gastrointestinal cancer who were scheduled for curative surgery. Low preoperative muscle mass was defined according to Asian Working Group for Sarcopenia criteria. Sleep disturbance was assessed using the Japanese version of the Pittsburgh Sleep Quality Index, including the subscales. [Results] Twenty-seven patients (31%) were classified as having low muscle mass. After adjusting for confounding factors, bad sleep quality, determined by the subscales, was significantly associated with low muscle mass. [Conclusion] Our results suggest that the evaluation of sleep quality is imperative for addressing low preoperative muscle mass in patients with gastrointestinal cancer.