Purpose: To evaluate daily physical-rest activities in cancer patients losing weight in relation to disease progression.
Experimental design: Physical activity-rest rhythms were measured (ActiGraph, armband sensor from BodyMedia) in relation to body composition (dual-energy X-ray absorptiometry), energy metabolism, exercise capacity (walking test), and self-scored quality of life (SF-36, Hospital Anxiety and Depression Scale) in weight-losing outpatients with systemic cancer (71 +/- 2 years, n = 53). Well-nourished, age-matched, and previously hospitalized non-cancer patients served as controls (74 +/- 4 years, n = 8). Middle-aged healthy individuals were used as reference subjects (49 +/- 5 years, n = 23).
Results: Quality of life was globally reduced in patients with cancer (P < 0.01), accompanied by significantly reduced spontaneous physical activity during both weekdays and weekends compared with reference subjects (P < 0.01). Spontaneous physical activity declined over time during follow-up in patients with cancer (P < 0.05). However, overall physical activity and the extent of sleep and bed-rest activities did not differ between patients with cancer and age-matched non-cancer patients. Spontaneous physical activity correlated weakly with maximum exercise capacity in univariate analysis (r = 0.41, P < 0.01). Multivariate analysis showed that spontaneous physical activity was related to weight loss, blood hemoglobin concentration, C-reactive protein, and to subjectively scored items of physical functioning and bodily pain (SF-36; P < 0.05-0.004). Anxiety and depression were not related to spontaneous physical activity. Patient survival was predicted only by weight loss and serum albumin levels (P < 0.01), although there was no such prediction for spontaneous physical activity.
Conclusions: Daily physical-rest activities represent variables which probably reflect complex mental physiologic and metabolic interactions. Thus, activity-rest monitoring provides a new dimension in the evaluation of medical and drug interventions during palliative treatment of patients with cancer.