Introduction
Despite advances in cancer therapy and survival, childhood cancer survivors experience a lifelong risk for treatment-related late effects.1 Compared to the general population, long-term survivors have an increased risk of cardiovascular disease,2 metabolic syndrome,2 and obesity.2 Compared to sibling comparisons or non-cancer controls, long-term survivors have a higher prevalence of cerebrovascular events,3 gastrointestinal complications,4 and pulmonary deficits.5 Adult survivors of childhood cancer experience a high and variable burden of chronic health conditions6 increasing their risk of early mortality.7
While risk of adverse health outcomes in survivors is largely driven by treatment exposures, chronic health conditions can be exacerbated by poor health behaviors. Among a large cohort of adult survivors of childhood cancer, the observed association between unhealthy lifestyle behaviors (e.g. diet, physical activity) and metabolic syndrome was stronger than the association between cranial radiation and metabolic syndrome.8 Adherence to a Mediterranean diet has been associated with lower body mass index and lower risk of metabolic syndrome among leukemia survivors.9 Moreover, physical activity has been associated with decreased mortality risk among childhood cancer survivors.10 Identifying and promoting modifiable lifestyle behaviors may be essential to improving the health outcomes and quality of life of long-term survivors.
Associations between sleep and health have not been fully elucidated in survivors; however, in the general population sleep duration is widely associated with several chronic health conditions. In cross-sectional examinations of national samples, short and long sleep durations have been associated with metabolic syndrome,11cardiovascular disease,12 and chronic kidney disease.13 Moreover, prospective associations between sleep disturbances and diabetes,14depression,15 gastrointestinal disease16, and progression to end-stage renal disease17 have also been reported. The high prevalence of self-reported sleep disturbances among survivors of childhood cancer has been well characterized;18,19 however, few studies have examined health status and poor sleep among childhood cancer survivors. The purpose of this study was to examine associations between short sleep duration and clinically-assessed health conditions among adult survivors of childhood cancer.