Impact of physical activity and sleep quality on quality of life of rural residents with and without a history of cancer: findings of the Day and Night Study

BACKGROUND: Lifestyle behaviors may impact quality of life (QoL). The relative impact of physical activity and sleep quality on QoL of individuals with and without a history of cancer living in underserved rural communities requires further study to inform health care and public health initiatives. METHODS: Individuals with and without a history of cancer were recruited from rural Virginia. We collected information on physical activity level (PAL), sleep quality (Pittsburgh Sleep Quality Index), and QoL (Short Form-36). Additional dimensions of physical activity and sleep were measured including ambient light exposure and sleep duration via Actiwatch2, and serum vitamin D and urine melatonin, which are markers of outdoor activity and sleep. RESULTS: A total of 124 cancer survivors and 48 cancer-free individuals were enrolled in the study. Mean age was 59 years, with the majority being women (89%) and Caucasian (76%). Breast cancer was the most common cancer (72%), and mean time from diagnosis to the survey was 8.1 years. Survivors were significantly less active, more likely to be inactive, and had significantly worse sleep quality and physical and mental health relative to cancer-free individuals (P<0.05). Quality of sleep and average sleep time were associated with physical (r=−0.371, P<0.001; r=−0.327, P<0.000) and mental health (r=−0.442, P=<0.001; r=−0.265, P<0.004), as was PAL (r=0.181, P=0.019; r=0.288, P=0.003). Self-reported outdoor activity was associated with mental health (r=0.233, P=0.003) and vitamin D3 (r=0.193, P=0.015). No association was found between melatonin, sleep quality, and QoL. Sleep quality, cancer status, body mass index, and sleep time were predictive of physical health, while sleep quality, sleep time, and outdoor activity were predictive of mental health. CONCLUSION: Quality of sleep is a significant predictor of mental and physical health, and important for cancer survivors who experience poorer QoL. Outdoor activity should be encouraged to improve mental health and vitamin D status, and interventions to improve sleep for those with poor sleep quality should be considered in cancer survivorship planning.