Objectives To evaluate sleep disorders in patients with FM and its potential association with cognitive impairment and disease severity
Methods 30 female patients with FM(ACR’90 criteria), 30 female patients with CP(non-oncological) and without depression, and 30 healthy female volunteers were included in a cross-sectional study. Inclusion criteria: postmenopausal women, BMI<34,9 kg/m². Exclusion criteria: comorbility, drugs potentially affecting central or autonomic nervous systems. Variables assessed: 1)demographic, anthropometric variables and education level. Depression test. 2)Nocturnal polysomnography assessing: a)neurologic variables: sleep latency (minutes to get to sleep), efficiency (% sleep time vs. time in bed), presence of cyclic alternating pattern(CAP) and hypnogram (sleep phases); and b) respiratory variables: presence of apneas/hypopneas, respiratory efforts related arousal (RERA) and inspiratory airflow limitation(hours of sleep with inspiratory flow limitation(normal <30%). 3) Neurocognitive study(10 questionnaires)assessing : attention(sustained, divided and selective), verbal memory and visual memory (working memory, learning ability, short- and long-term retention and logic memory) and information processing speed; and 4) Tender point count (out of 18) and Fibromyalgia Impact Questionnaire (FIQ) in patients with FM.
Results Patients with FM:1) Age 53.8±3.2 y (p= ns vs. other groups); no differences regarding other variables. 2)Polysomnography a)Neurologic variables:>latency (32.5±25.1 min) and<sleep efficiency (76.6±11.9) compared to healthy volunteers (p =0.04 and p =0.028, respectively) and without differences versus CP patients;>presence of CAPs (60.2 ±9.9) compared with CP patients and healthy female (p=0.04 and p=0.003, respectively); no differences in hypnogram. b) Respiratory variables: no differences between groups regarding the presence of apneas/hypopneas;>RERA compared to CP patients and healthy female; presence of inspiratory flow limitation in 46% of FM patients, 11.7% of CP patients and 3% of healthy female with >sleep time with such limitation 51% sleep hours in FM patients vs. 36% in CP patients, and more severe in FM (30 ±22%) than in CP patients (14.7 ±12,8%) and healthy female (9 ±10.2%) (p =0.004 and p =0.001, respectively). These sleep disorders were associated with a greater overall sleep fragmentation only in the FM group (p =0.04). There was a significant relation between sleep and cognitive variables in the FM group: sleep latency and visual attention (p=0.01); sleep efficiency and attention capacity (p <0.02), scanning speed (p =0.01) and visual processing (p =0.01) and inspiratory flow limitation and recent verbal memory (p <0.05). No significant relation with tender point count or FIQ was found.
Conclusions The neurologic impairments detected by polysomnography agree with the already reported in the literature. We have detected an inspiratory flow limitation in FM patients, due to a greater airway resistance, which could explain the poor sleep quality in these patients and which could also be involved in the cognitive deficits/impairments FM patients suffer.
Acknowledgements Funding: Marató TV3 grant
Disclosure of Interest None Declared