The role of oxidative stress in the relation between fibromyalgia and obstructive sleep apnea syndrome.

OBJECTIVE The aim of this study is to examine the involvement of oxidative and antioxidative parameters and to evaluate the relation between fibromyalgia (FMS) and obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS Oxidative stress was determined by measuring the levels of malondialdehyde (MDA) and antioxidative parameters (superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase [GPx]) in 131 randomly selected patients with OSAS. The control group was composed of 129 subjects with no clinical OSAS symptoms. OSAS was diagnosed by polysomnographic tests. All patients underwent overnight polysomnographic recording. The diagnosis of fibromyalgia was made following the diagnostic criteria of the American College of Rheumatology. The FMS patients used visual analog scales (VAS) to evaluate their pain, and they completed the FMS Impact Questionnaire (FIQ). All subjects completed the 36-item Short Form Health Survey (SF-36) and the Beck Depression Inventory (BDI). RESULTS In the OSAS + FMS group, CAT, SOD, and GDX were found to be statistically significantly lower and MDA was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). A significant difference was found about gender between the OSAS group and the OSAS+FMS group (p = 0.0001). In the OSAS + FMS group, BDI was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). In the OSAS + FMS group, SF 36 was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). No differences were observed between the groups about AHI, minimum O2 saturation, or total sleep time values. About the presence of FMS presence, no differences were detected among the mild, moderate, and severe OSAS groups (p = 0.831). A negative correlation was determined between AHI and VAS and total sleep and sensitive points (p = 0.0001). A negative correlation was shown between CAT and GPX, SOD and apnea/hypopnea index (AHI) (p = 0.0001). A positive correlation was shown between CAT, GPX and SOD (p = 0.0001). A minimum O2 saturation was detected. A positive correlation between MDA and AHI (p = 0.0001), and a negative correlation between MDA and O2 saturation (p = 0.0001) were found. CONCLUSIONS OSAS and FMS were highly prevalent, which indicated that oxidative stress might play a role in the pathophysiology of both diseases, especially if they co-exist in the same patient.