Characteristics of circadian rhythms in rest-activity and energy expendi-ture in cancer in-patients

Abstract

The objective of the current study was to assess the rest-activity (RA) and energy expenditure (EE) rhythms in cancer in-patients. Twenty chemothera-py receiving cancer in-patients (10 males and 10 females) and ten apparently healthy human subjects (5 males and 5 females) wore a non-invasive elec-tronic device – the Actical on their non dominant wrist. Data were recorded at 1-minute epoch for at least 3-4 consecutive days. Significant differences in RA and EE patterns were observed between cancer in-patients and control subjects, irrespective of gender. Control subjects showed absolute rhythm detection ratio in RA and EE, whereas, ratio was of low magnitude in cancer patients, especially with reference to EE. Statistically significant decrement in circadian amplitudes and advancement in circadian peaks of RA and EE were observed in cancer in-patients as compared to control subjects. Significant independent effects of factors, namely ‘disease’ and ‘gender’ on total activity count (TAC), average activity count (AAC), total energy expenditure (TEE) and average energy expenditure (AEE) were observed. TEE and AEE were signifi-cantly lower in cancer in-patients as compared to control subjects. Further, factors, ‘disease’ and ‘gender’ also produced significant effects on activity energy expenditure (AcEE), metabolic energy expenditure (MET) and resting energy expenditure (REE). In conclusion, the findings indicate disruption of the circadian rhythms in rest-activity and energy expenditure in cancer in-patients. This disruption is gauged from alterations in rhythm characteristics of RA and EE. However, additional studies involving more patients are re-quired for further validation of the present findings.