1. Evaluation of sleep architecture and functional level in Fibromyalgia patients with and without obstructive sleep apnea syndrome I. Bouloukaki1, L. Konstantara1, C. Mermigkis1, R. Pateli1, V. Moniaki1, E. Mauroudi1, S. Schiza1 1 Sleep Disorders Center, Department of Thoracic Medicine, University of Crete, Heraklion, Greece
BACKGROUND:
Clinical and epidemiological studies show that sleep disturbances directly influence musculoskeletal pain, fatigue, mood, and overall well-being. 
There are limited data concerning the association between obstructive sleep apnea (OSA) and fibromyalgia (FMS).
Table 2. Selected PSG variables of the total FMS sample and comparison in parameters between 2 groups.
Total
N=41
Group 1
N=19
Group 2
N=22
P-value
Diagnostic PSG
SE (%)
66.7 ± 9.7
64.5 ± 9.2
68.6 ± 9.7
0.19
WASO (min)
100 ± 32.4
110.7 ± 31.1
91.3 ± 31.4
0.059
NREM (%)
87.9 ± 13.5
90.9 ± 4.5
85.4 ± 17.8
0.2
SWS (%)
8.0 ± 5.1
7.7 ± 2.8
8.3 ± 6.5
0.69
REM (%)
9.9 ± 10.4
9.5 ± 4.1
10.4 ± 4.7
0.51
Sleep latency (min)
60.1 ± 60.9
66.1 ± 71.5
55.1 ± 51.4
0.57
REM latency (min)
237.7 ± 90.2
248.1 ± 99.4
228.8 ± 82.9
0.50
AHI
12.9 ± 17.2
24.8 ± 19.3
2.6 ± 2.2
<0.001* AI
36.2 ± 11.3
39.6 ± 10.6
33.3 ± 11.3
0.07
ODI
14.3 ± 20.4
27.9 ± 23.5
2.6 ± 2.3
Mean SaO2 (%)
94.7 ± 2.4
93.1 ± 2.4
96.1 ± 1.2
Minimum SaO2 (%)
85.1 ± 12.3
78.7 ± 15.6
90.6 ± 3.1
0.001*
AIM: To assess the difference in sleep quality and functional status between FMS patients with and without OSA.
METHODS: 
Forty one patients were evaluated in the Sleep Disorders unit over 5 years meeting standard clinical criteria for FMS.
The diagnosis of fibromyalgia was made following the fibromyalgia diagnostic criteria of the American College of Rheumatology (ARA 2010 version).
All patients underwent polysomnography.
The Fibromyalgia Impact Questionnaire (FIQ) assessed participants’ severity of symptoms.
Depression level was assessed with Beck Depression Inventory (BDI).
Subjective daytime sleepiness was assesed by Epworth sleepiness scale (ESS).
Table 3. Questionnaire scores of the total FMS sample and comparison between 2 groups.
Questionnaires
Total
N=41
Group 1
N=19
Group 2
N=22
P-value
FIQ
50.9 ± 23.1
53.2 ± 21.7
48.5 ± 24.7
0.56
BDI
15.0 ± 8.1
14.2 ± 8.3
15.9 ± 8.1
0.53
ESS
11.9 ±5.1
13.3 ± 4.7
10.7 ± 5.2
0.07
RESULTS I:
Nineteen out of 41 (46%) patients had an AHI greater than 10.
The patients were then divided into two groups in terms of OSA presence: group 1 which included 19 FMS patients with OSA and group 2 with 22 FMS patients without OSA.
RESULTS II:
A statistically significant correlation was found between FIQ scores and mean SO2 (%) for all patients (r = -0.35; p = 0.048) and a statistically significant trend with sleep latency (r=0.36, p=0.07).
In group 1, SE (%) (r=0.52, p=0.033) and presence of diabetes (r=0.55, p=0.023) was correlated with FIQ score. In group 2 gender (r=0.57, p=0.027) and REM (%) sleep (r=-0.55, p=0.034) were correlated with FIQ score.
Table 1. Baseline demographic characteristics of the total FMS sample and comparison in parameters between 2 groups.
Characteristics
Total
N=41
Group 1
N=19
Group 2
N=22
P-value
Age (years)
51.0 ± 10.8
53.7 ± 9.5
48.7 ± 11.5
0.14
Gender, male (%)
7 (17%)
6 (44.3%)
1 (4.7%)
0.02*
Menopause, n (%)
16 (39.0%)
7 (36.8%)
9 (40.9%)
0.79
BMI (kg/m2)
29.2 ± 5.9
32.5 ± 5.4
26.3 ± 4.8
<0.001*
Current smokers, n (%)
10 (24.4%)
6 (31.6%)
4 (18.2%)
0.61
Comorbidities
Diabetes mellitus, n (%)
8 (19.5%)
5 (26.3%)
3 (13.6%)
0.30
Hypertension, n (%)
12 (29.3%)
8 (42.1%)
0.09
Hypothyroidism, n (%)
11(26.8%)
3 (15.8%)
8 (36.4%)
CONCLUSIONS:
Our data suggest that there might be a relation between oxygen saturation levels and pain in FMS patients, supporting the probable effects of intermittent hypoxia resulting from OSA on functional status of these patients.
The high prevalence of OSA requires more research to determine whether OSAS treatment will benefit the symptoms of FMS.
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