DAILY ACTIVITY LEVELS AND SLEEP QUALITY IN BREAST CANCER

Rest-activity circadian rhythm (RAR) analysis is a valuable tool to evaluate daily physical activity levels and sleep quality in breast cancer (BC) women, including BC survivors, a population less considered in the scientific literature. Indeed, the role of physical activity is recognised even in tertiary cancer prevention due to its action either on physical or psychological human spheres. In managing the quality of life in BC women, sleep assessment and its relationship with physical activity also raise attention. Several studies reported that an increase in physical activity practice might lead to better sleep quality. All these aspects have been less investigated in BRCA1/2 carrier women. BRCA1/2 are deleterious and high-invasive gene mutations, predisposing to a very aggressive breast and/or ovarian cancer also at a young age. The present PhD thesis evaluates RAR, sleep, and their relationship in two populations: a cohort of 5-year BC survivors and a sample of BRCA1/2 women. For the first study, 28 women (15 5-year BC survivors and 13 healthy controls) were 7-day long actigraph monitored and RAR analysis was performed with both parametric and non-parametric approaches. BC survivors showed a statistically lower MESOR (Midline Estimating Statistic of Rhythm), amplitude, L5 (nocturnal activity), and M10 (daily activity), while IV (Intradaily Variability) was higher than the control group. These results are the first experimental evidence that RAR alterations persist after 5 years since the primary diagnosis. Furthermore, BC survivors are less active than healthy controls and need practical intervention to increase their activity levels. For the second study, 27 women with BRCA1/2 mutations were 7-day long actigraph monitored, while 63 filled in the PSQI (Pittsburgh Sleep Quality Index) and the GSL-TPAQ (Godin Shepard Leisure-Time Physical Activity Questionnaire) questionnaires to assess sleep and physical activity, respectively. The 27 actigraph-monitored women were stratified, based on the development of cancer diagnosis, in affected and unaffected. RAR and actigraphic sleep analysis showed no statistically significant differences between the two groups, even though the affected women seemed to sleep worse than the unaffected. Based on the PSQI score, the women were stratified into good and bad sleepers: good sleepers were significantly more active than bad sleepers. Based on the GSL-TPAQ score, women were stratified into active and inactive: active women showed a better body composition and significantly lower insulin level and better sleep than inactive women. Finally, the regression analyses disclosed the positive effect of physical activity on sleep. More specifically, the prevalence ratio of being a good sleeper significantly increased with the increase in amount, intensity, and frequency of physical activity. This cross-sectional analysis of 63 women sheds light on a possible association between physical activity and sleep in BRCA1/2 mutation carriers. Considering the large attention that the BRCA1/2 carriers’ quality of life is receiving, a physical activity intervention could potentially improve the sleep quality in these women, also reflecting in an enhanced quality of life.