Background: The prevalence of restless legs syndrome (RLS) among the general population is 2–15%, and with fibromyalgia syndrome (FMS) 2%. Both RLS and FMS are more common among women. The aim of our study was to evaluate the prevalence of RLS in a group of female patients diagnosed with FMS and to compare the occurrence of symptoms of daytime sleepiness and experienced sleep disorders between fibromyalgia patients with or without RLS. Method: Three hundred and thirty-two female patients, 20–60 years old, diagnosed with FMS at Skönviks Rehab between 2002 and 2006, answered a questionnaire mailed to their home address. The questionnaire consisted of the international RLS study group criteria as well as of questions concerning symptoms of insomnia and daytime sleepiness measured according to the Epworth Sleepiness Scale. Results: Nearly 64% of the women were also suffering from RLS. More patients suffering from both RLS and FMS were affected by problems of initiating and maintaining sleep than those suffering from FMS only. More patients suffering from both RLS and FMS did not feel refreshed on awakening compared with those suffering from FMS without RLS. The patients with concomitant RLS and FMS were more often hypersomnolent than those suffering from FMS only. Conclusion: This study shows that 64% of a group of female patients diagnosed with fibromyalgia also concurrently suffered from RLS. Compared with patients who suffer from FMS only, patients with both FMS and RLS more often experience sleep disturbances and pronounced daytime sleepiness.

The prevalence of RLS increased progressively with pain severity and even more sharply with the degree of pain spreading in women recruited from the general population. Both acute and chronic pain was associated with RLS-related symptoms.

Abstract Background and aims: Chronic widespread pain (CWP) is associated with poor quality of sleep, but the detailed underlying mechanisms are still not fully understood. In this study we investigated the influence of CWP on morning cortisol and fasting glucose concentrations as well as sleep disordered breathing. Methods: In this case-control study, subjects with CWP (n=31) and a control group without CWP (n=23) were randomly selected from a population-based cohort of women. Current pain intensity, sleep quality, excessive daytime sleepiness [Epworth sleepiness scale (ESS)], psychiatric comorbidity and occurrence of restless legs syndrome (RLS) were assessed. Overnight polygraphy was applied to quantify sleep apnoea, airflow limitation and attenuations of finger pulse wave amplitude (>50%) as a surrogate marker for increased skin sympathetic activity. Morning cortisol and fasting glucose concentrations were determined. Generalised linear models were used for multivariate analyses. Results: CWP was associated with higher cortisol (464±141 vs. 366±111 nmol/L, p=0.011) and fasting glucose (6.0±0.8 vs. 5.4±0.7 mmol/L, p=0.007) compared with controls. The significance remained after adjustment for age, body mass index, RLS and anxiety status (β=122±47 nmol/L and 0.89±0.28 mmol/L, p=0.009 and 0.001, respectively). The duration of flow limitation in sleep was longer (35±22 vs. 21±34 min, p=0.022), and pulse wave attenuation was more frequent (11±8 vs. 6±2 events/h, p=0.048) in CWP subjects compared with controls. RLS was associated with higher ESS independent of CWP (β=3.1±1.3, p=0.018). Conclusions: Elevated morning cortisol, impaired fasting glucose concentration and increased skin sympathetic activity during sleep suggested an activated adrenal medullary system in subjects with CWP, which was not influenced by comorbid RLS. Implications: CWP is associated with activated stress markers that may deteriorate sleep.