This study concludes that higher physical activity is associated with poor SE due to increased night-time activity. There was a significant reduction in physical activity and sleep observed during seven weeks with moderate association between them. The significant circadian rhythm deregulation however showed poor association with the other variables.Level of Evidence: 2b.

This longitudinal study recruited 27 participants diagnosed with HNC who were planning to undergo chemoradiotherapy. Accelerometers worn for 3 days during the 1st, 3rd, and 7th weeks of chemoradiotherapy were used to assess physical activity levels (step count and metabolic equivalents [METs]) and sleep quality (total sleep time [TST], sleep onset latency [SOL], and sleep efficiency [SE]). Urine melatonin analysis was conducted using the morning void urine sample on 1st, 3rd, and 7th weeks. The change in variables during the seven weeks and the correlation between them were analyzed.

During the seven weeks, trends of reduction in variables of physical activity, sleep and circadian rhythm were observed with significant decrease in step count, TST and melatonin levels. SE was found to have strong negative correlation with physical activity. TST was found to have moderate correlation with SE and step count. The variables of physical activity also showed moderate correlation among them.