Background Sleep deprivation contributes to many abnormalities: immune system deficiencies, pain, fatigue and impaired quality of life. About 54-70% of patients with rheumatoid arthritis (RA) have sleep complaints and this can influence the control of disease activity [1,2].
Objectives Primary objective was to evaluate the influence of the level of RA activity on objective variables measured by by polysomnography (PSG). Secondary objective was to evaluate the correlation of the quality of sleep, evaluated subjectively by the Pittsburgh Sleep Quality Index (PSQI), with common complaints such as pain, depression and functional capacity.
Methods Women with a diagnosis of RA according to the ACR/EULAR 2010 criteria and sleep quality complaints (PSQI >5) were submitted to whole-night PSG in a sleep laboratory . Disease Activity Score (DAS28) was also used in the evaluation of RA and the women were divided in two groups: DAS28 <3.2 (group A) and the other with DAS28 ≥3.2 (group B). Pain (by the visual analogue scale, VAS), depression (evaluated using the Beck Depression Inventory, BDI), and functional capacity (by the Timed Up & Go Test, TUG).
The generalized linear model (GLM) test was used to compare the variables between groups. Pearson correlation was calculated. Statistical analysis considered α ≤0.05.
Results In the study period, 43 women were evaluated. Group A (DAS28: 2.23±0.62 mm/h) had 16 participants and was aged 54.75±7.05 years. Group B (DAS28: 4.38±0.84 mm/h) had 27 women aged 54.37±7.17 years. Both groups had a low sleep efficiency (78.76±8.47 and 78.14±13.33; p=0.87) and superficial sleep (> %N1): 10.09±4.32 versus 9.58±4.63 (p=0.72). Both had also a short period of REM sleep (16.41±7.13 versus 16.98±5.65; p=0.77). Group B had a higher wake after onset sleep (A: 67.79±33.49 versus B: 74.17±50.02; p=0.65) and higher arousal index (A: 13.21±7.04 events/h versus B: 17.75±29.16 events/h; p=0.54) and higher apnea-hypopnea index (A: 4.61±5.45 events/hour e B: 11.27±12.82 events/hour; p=0.05). A significant correlation was found between PSQI and pain (r =0.43; p=0.004) and a positive correlation with TUG (r =0.33; p=0.03) e BDI results (r =0.60; p=0.001).
Conclusions Women with higher DAS28 tend to have a higher frequency of sleep disorders, impaired quality of life, function and more depression, which clearly demonstrates the extent of the impairment caused by RA.
Iber C, Ancoli-Israel S, Chesson A, Quan S. for the American Academy of Sleep Medicine. The AASM manual for the scoring of sleep and associated events: rules, terminology and technical specifications. 1st ed. Westchester, IL: American Academy of Sleep Medicine; 2007
Disclosure of Interest None declared