Does sleep disorders associated with functioning, functional capacity and fatigue in breast cancer survivors?
Cancer. Survivors. Sleep disorders. Functioning. Quality of life
Introduction: Breast cancer (BC) is the most diagnosed among women, with a high chance of cure due to early diagnosis and less aggressive and effective treatments, which can cause adverse effects. Among these, the reduction of functionality, fatigue, low aerobic capacity and sleep disturbances are highlighted. In this perspective, sleep disorders can cause negative effects in the life of women surviving BC. In this perspective, sleep disorders can cause negative effects in the life of women surviving BC. Current evidence on the effects of sleep disturbance is limited, especially after treatment and throughout disease-free survival. Objective: To evaluate the prevalence of sleep disorders and its association with the functional capacity, fatigue, functioning and quality of life of women who survived BC and outside the clinical treatment of the disease. Methodology: This is a cross-sectional study, developed with 32 women who survived BC, at least one year after clinical treatment. The data collection instruments consisted of general and clinical information on the disease and questionnaires World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0); Pittsburgh Sleep Quality Index (PSQI); Functional Assessment of Cancer Therapy-Fatigue (FACT-F); Disabilities of the arm and Shoulder (DASH); International Physical Activity Questionnaire (IPAQ, short version), plus the six-minute walk test (6MWT). Statistical analysis was performed with SPSS 20.0. The normal distribution of the data was performed by the Shapiro-Wilk test, followed by the Spearman correlation test and the Student's t test and the Mann Whitney U test. To verify the clinical effect, Cohen's d was used and the bivariate linear regression test was used. The significance was set at p <0.05. Results: Among the main findings, it is worth noting that more than 70% of women surviving the cancer, even after the end of clinical treatment, present sleep disorders. This precariousness correlates with subjective sleep quality (rs = 0.769), sleep disturbances (rs = 0.624), sleep latency (rs = 0.625), sleep duration (rs = 0.581), and sleep disturbances during the day (rs = 0.654). A significant difference in sleep quality was observed with the worst scores for the FACT-F, DASH and WHODAS 2.0 scales (p <0.05). Precarious sleep was a predictor of worse scores for fatigue, quality of life, functional capacity of the upper limbs and functioning (p <0.05). Conclusions: The findings show that precarious sleep is a predictor of worse scores for fatigue, quality of life, functional performance of the upper limbs, and functioning. Sleep precarious proving the negative impacts of the precarious sleep of these women and denoting the relevance and urgency of inclusion of aspects related to sleep in the clinical evaluations and therapeutic conducts directed to women survivors of breast cancer.