High prevalence of restless legs syndrome among women with multi-site pain: a population-based study in Dalarna, Sweden.

BACKGROUND: The chronic pain (CP) and chronic multi-site pain (CMP) condition is a highly prevalent health problem. Several studies have reported a high (31-64%) prevalence of co-morbid restless legs syndrome (RLS) in patients with fibromyalgia, one specifically defined form of chronic widespread pain. The current study explored the association between CMP and RLS. METHOD: The study included 4040 respondents to a postal questionnaire sent to 10,000 women in the age range of 18-64 years and randomly selected from the general population. Complete questionnaire data on type (acute/chronic), degree (mild to severe) and spreading (0-5 body zones) of pain, as well as RLS symptoms (validated questionnaire), were obtained from 3060 subjects. Information on lifestyle, anthropometrics, co-morbidities and medication was collected. RESULTS: RLS prevalence increased from 9.6% in subjects with no report of pain to 23,9%, 26.4%, 39.2%, 44.9% and 54.8% in those reporting one, two, three, four and five pain areas, respectively (p < 0.001). Further, RLS prevalence increased from 9.6% (no pain) to 27.9%, 37.9% and 42.4% in subjects with mild, moderate and severe chronic pain (p < 0.001). Multi-site pain, pain localized in the leg, extended pain duration and co-morbid psychiatric disorder were all independently associated with a RLS diagnosis in a multiple regression analysis. CONCLUSION: 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.

High incidence of iron depletion and restless leg syndrome (RLS) in regular blood donors: intravenous iron sucrose substitution more effective than oral iron.

BACKGROUND AND OBJECTIVES: Iron depletion is common in regular blood donors. The objective of the study was to investigate the frequency and severity of iron depletion in regular blood donors and whether IV iron is more effective than oral to avoid iron depletion and symptoms thereof, especially restless legs syndrome (RLS). METHOD: One hundred and twenty blood donors with at least five previous whole blood donations were randomized to receive either IV iron sucrose (Venofer(®), RenaPharma/Vifor, Uppsala, Sweden), 200 mg, or to 20×100 mg of oral iron sulphate (Duroferon(®), GlaxoSmithKline, Stockholm, Sweden), after each blood donation during 1 year. Iron status and RLS incidence and severity were investigated. RESULTS: Iron status was generally poor among regular blood donors, especially in women, with a high incidence of iron depletion (>20%) and RLS (18%). The IV iron group increased storage iron to a greater extent than the oral iron group after 12 months (P=0·0043). Female donors were more responsive to IV iron sucrose compared to oral iron sulphate, particularly female donors below 50 years of age. RLS severity scores were significantly lower in the IV iron group. The two treatments were safe. CONCLUSION: Iron status is poor in regular blood donors, restless legs syndrome is common, and the routine iron supplementation is insufficient. IV iron sucrose substitutes iron loss in blood donors more efficiently compared with oral iron sulphate, especially in women. Iron substitution to blood donors should be individualized and based on P-ferritin monitoring.

Restless legs syndrome.

Restless legs syndrome (RLS) is a common neurological sensory-motor disorder that is characterized by intense restlessness and unpleasant creeping sensations deep inside the lower legs. Symptoms appear when the legs are at rest and are worst in the evening and at night. They force patients to keep moving their legs, and often to get out of bed and wander about. Periodic limb movements (PLMS) are also common during sleep amongst those suffering from RLS, and sleep efficiency is severely reduced. There are idiopathic as well as symptomatic forms of RLS, the latter being associated with e.g. pregnancy, iron deficiency and chronic renal failure. A family history of RLS is very common and pedigrees in these cases suggest an autosomal-dominant transmission with high penetrance. Genetic investigations have been performed in order to identify genes associated with RLS. Several loci have been found (on chromosomes 12q, 14q, 9p, 2q, 20p and 16p). Pathophysiology of RLS remains incompletely understood. However, advanced brain imaging studies and positive results of dopaminergic treatment suggest that RLS may be generated by dopamine dysfunction locally within the central nervous system. At present, there is a wide range of treatment options including levodopa, dopamine agonists, opioids, benzodiazepines, antiepileptic drugs and iron supplements.

Restless legs syndrome among women: prevalence, co-morbidity and possible relationship to menopause.

OBJECTIVES: Restless legs syndrome (RLS) is a common neurological movement disorder with a female preponderance and an increasing prevalence with age. During the menopausal transition, sleep is affected. Prior studies suggest that female hormones are associated with the clinical manifestation of RLS. METHODS: A random sample of 5000 women aged 18-64 years was selected from the general Swedish population. They were sent questions on RLS, general health, sleep problems, reproductive health and menopausal state. RESULTS: The response rate was 70.3%; 15.7% of the women were diagnosed with RLS. Prevalence increased with age. RLS subjects more often had symptoms of affected sleep and depressed mood. Co-morbidity with heart disease was more common among RLS subjects, whereas hypertension and diabetes mellitus were not. There was a strong association between vasomotor symptoms and RLS but no statistical relationship between use of hormone replacement therapy, postmenopausal state and RLS. CONCLUSION: The prevalence of RLS among Swedish women is high. RLS sufferers more often suffered from depression and heart disease, whereas no such associations were noted for diabetes or hypertension. We found an increased prevalence of RLS among women with vasomotor symptoms (night sweats) during the menopausal transition but not among women using hormone replacement therapy.

Light room therapy effective in mild forms of seasonal affective disorder--a randomised controlled study.

BACKGROUND: The most common way to provide bright light therapy to Swedish patients with Seasonal Affective Disorder (SAD), is treatment in a light therapy room. Since few studies have evaluated treatment provided in this setting and few have evaluated the effect of bright light in sub-clinical SAD (S-SAD), such a study including a one-month follow-up was designed. METHODS: Fifty adults recruited from a previous prevalence study and clinically assessed as having SAD or S-SAD, were randomised to treatment in a light room or to a three-week waiting-list control group. The Hamilton Depression Rating Scale-Seasonal Affective Disorders Self-rating 29-items Version (SIGH-SAD/SR) was used to measure depressive mood at baseline, directly following treatment and at the one-month follow-up. RESULTS: ANCOVA with adjustment for baseline depression score, showed a significant main effect for the light room therapy group (p<0.001). Fifty-four percent (n=13/24) improved > or = 50% while no such improvement was seen in the control condition (n=0/24). After merging the two groups, repeated measures ANOVA confirmed the experimental analysis (p<0.001). At the one-month follow-up, 83.0% (n=39/47) had improved > or = 50% and 63.8% (n=30/47) had normal depression scores, i.e. < or = 8. CONCLUSIONS: Light room therapy was effective in reducing depressive symptoms in subjects with winter depressive mood. Results were maintained over a period of one month.

Determination of melatonin in human plasma with solid-phase extraction, high-performance liquid chromatography and fluorescence detection.

A new bioanalytical method for the determination of melatonin in plasma with high-performance liquid chromatography (HPLC) and fluorescence detection preceded by solid-phase extraction has been developed and validated. Melatonin was extracted from 3 mL plasma using a Waters Oasis HLB solid-phase extraction cartridge and the elute was evaporated to dryness and dissolved in 200 microl mobile phase; acetonitrile-phosphate buffer, 0.01 M pH 7.2 (25:75, v/v). 125 microL was injected into the HPLC system and separation was carried out on a Waters SymmetryShield RP18 column 5 microm (250 x 4.6 mm). Excitation and emission wavelengths were set to 285 nm and 345 nm, respectively. The HPLC system was able to separate melatonin and internal standard (5-fluorotryptamine) from other endogenous indole compounds such as serotonin and tryptophan. Determination down to 0.10 nmol/L was possible, with an intra-assay precision of about 13%. Melatonin was stable in plasma for at least 30 days at about 23 degrees C.

Prevalence of restless legs syndrome among men aged 18 to 64 years: an association with somatic disease and neuropsychiatric symptoms.

Standardized diagnostic criteria determined by the International Restless Legs Syndrome Study Group were used to investigate the current prevalence of restless legs syndrome (RLS). Possible associations between RLS and neuropsychiatric and somatic complaints were also investigated. A random sample of 4,000 men living in central Sweden were sent a questionnaire that included questions about sleep habits, symptoms of sleepiness, and somatic and neuropsychiatric complaints. Four symptom questions accepted as minimal diagnostic criteria for RLS were also included. Odds (OR) ratios and 95% confidence interval (CI) for different variables were calculated by means of multivariate logistic regression; 5.8% of the men suffered from RLS. The prevalence of RLS increased with age. Sleep-related complaints were more frequent among the RLS sufferers. Complaints of headache at awakening and daytime headache were reported three to five times more frequently among RLS sufferers and there was a tendency toward reported social isolation related to RLS. Subjects with RLS more frequently reported depressed mood (OR, 2.6; 95% CI, 1.8-3.8), and complained more often of reduced libido (OR, 2.2; 95% CI, 1.4-3.3). RLS sufferers more frequently reported hypertension (OR, 1.5; 95% CI, 0.9-2.4) and heart problems (OR, 2.5; 95% CI, 1.4-4.3). Results show that restless legs syndrome is common among men. It is hypothesized that RLS may be associated with several somatic and neuropsychiatric symptoms.

Treatment of snorers with a volatile oil: a randomized, double-blind placebo-controlled trial.

Snoring is a significant problem both for the patient and for the bed partner. Seventy-two male and female heavy snorers and their bed partners participated in a double-blinded, placebo-controlled study on the effects of a volatile oil administered by gargling. The patients were diagnosed as heavy snorers after they underwent overnight polysomnography showing that their apnea indexes were below 5, thus sleep apnea patients were not included in the study. The participants and their partners filled out evaluations concerning snoring intensity, mouth dryness, nasal stuffiness and the Epworth Sleepiness Scale prior to and after using the volatile oil or placebo for 14 consecutive nights. There were no statistically significant decreases in snoring as graded by the bed partner or in mouth dryness, nasal stuffiness, or the Epworth Sleepiness Scale scores graded by the patients who were randomized to use the volatile oil. The results of this study indicate that this volatile oil is not an effective treatment in patients presenting with symptoms of snoring.

Restless Legs Syndrome among working-aged women.

A random sample of 200 women, aged 18-64 years, living in a county in mid-Sweden, was sent a questionnaire that included questions about sleep habits, symptoms of sleepiness and neuropsychiatric complaints. Standardized diagnostic criteria determined by the International Restless Legs Syndrome Study Group were used to investigate the prevalence of restless legs syndrome (RLS). Possible associations between RLS and neuropsychiatric complaints were also investigated. Odds ratios for different variables were calculated by means of multivariate logistic regression. 11.4% of the women suffered from RLS. Sleep-related complaints were more frequent among RLS sufferers than among nonsufferers. Complaints of daytime headache were reported 5 times more frequently among RLS sufferers, and there was a tendency towards social isolation related to RLS. Subjective problems in performing work due to sleepiness were ninefold among the women with RLS. These results indicate that RLS together with an association to neuropsychiatric symptoms is common among working-aged women.

Sleep-disordered breathing and occupational accidents.

OBJECTIVES: The relationship between a common type of sleep disturbance, sleep-disordered breathing, and the risk of becoming involved in an occupational accident was studied. METHODS: A 10-year retrospective comparison was made of occupational injuries reported to the Occupational Injury Statistics Division of the Swedish National Board of Occupational Safety and Health. The injury rates for 704 consecutive patients suffering from sleep-disordered breathing were compared with the rates for an employed, age-matched random sample of 580 subjects, drawn from the general population. RESULTS: The risk of being involved in an occupational accident was about 2-fold among male heavy snorers and increased by 50% among men suffering from obstructive sleep apnea syndrome (OSAS). For females the risk increased by at least 3-fold among heavy snorers and OSAS patients. Reduced vigilance and attention due to sleep-disordered breathing are the proposed mechanisms behind the results. CONCLUSION: The early identification and treatment of persons suffering from sleep-disordered breathing would not only have positive impact on individual health and well-being but also on occupational safety.

Adverse health effects among women living with heavy snorers.

Women living with heavy snorers were more frequently affected by symptoms of insomnia, morning headache, daytime sleepiness, and fatigue than women living with non-snorers. Questionnaire data were collected from 1,032 women 30 to 64 years of age residing in Dalarna county, in mid-Sweden. There were indications of a "dose-response relationship" between the conjectured sound exposure and reported symptoms, regardless of whether the female herself snored. Sleeping in separate bedrooms did not seem to give the women any alleviation. The results point to a possible contributory cause of disturbed sleep, morning headache, and daytime sleepiness among women living with a snoring spouse. The results also indicate that prevention and treatment of snoring are important issues for the couple as well as for the snorer.

[Restless legs. A much neglected syndrome]. / Restless legs. Föga uppmärksammat syndrom.

Ekbom's syndrome, or 'restless legs syndrome' (RLS), not only causes symptoms in the extremities during waking hours, but also sleep disturbance and daytime fatigue. Although the prevalence of RLS has been estimated to be 1-5%, the condition is probably underdiagnosed and undertreated. Its onset may occur at any age, and there may be long periods of remission, but the condition is generally chronic. In its primary form, there is often a family history of the disorder suggestive of an autosomal dominant mode of inheritance, where the results of EMG (electromyography) and nerve conduction studies are normal. In secondary forms, clinical signs and laboratory evidence of an associated abnormality are present. The most characteristic symptom of RLS is the spontaneous occurrence of paraesthesia or dysaesthesia during waking hours. The symptoms of RLS are worse or exclusively present during rest, and are partially or temporarily relieved by activity. About 80 per cent of RLS patients also suffer from 'periodic limb movements during sleep' (PLMS), which may cause microarousals during sleep. The diagnosis of RLS is based on characteristic clinical criteria, and the sleep disturbance is diagnosed polysomnographically. L-dopa and clonazepam have been found successful in the treatment of primary RLS, though lifelong treatment is often necessary.

Improvement of subjective work performance among obstructive sleep apnea patients after treatment with continuous positive airway pressure.

Obstructive sleep apnea syndrome (OSAS) is a significant problem for some patients presenting with snoring and excessive daytime sleepiness. The 'golden standard' therapy in OSAS is considered to be nasal continuous positive airway pressure (CPAP). The effects of CPAP on work performance in sleep apnoics has not been studied previously. One hundred and fifty-two patients with OSAS participated in an open label study. The patients were diagnosed as suffering from severe OSAS after they underwent overnight polysomnography showing that their apnea indexes were at least 20. The participants answered four questions concerning self-perceived work performance prior to and after using CPAP during 6 months. There were highly statistically significant decreases (P < 0.000001) in work performance difficulties as graded by the patient. The results of this study indicate that CPAP treatment improves subjective work performance in patients suffering from OSAS.

Afternoon serum-melatonin in sleep disordered breathing.

OBJECTIVES: To study afternoon serum-melatonin values in patients with sleep disordered breathing. Melatonin has a strong circadian rhythm with high values during the night-time and low values in the afternoon. Sleep disordered breathing may change the circadian rhythm of melatonin which may have diagnostic implications. SETTING: The Sleep Laboratory, The Department of Internal Medicine, Avesta Hospital, Sweden, and the Department of Anaesthesiology, Glostrup University Hospital, Copenhagen, Denmark. SUBJECTS: We examined 60 consecutive patients admitted for sleep disordered breathing and 10 healthy non snoring controls. The patients underwent a sleep apnoea screening test having a specificity of 100% for the obstructive sleep apnoea syndrome (OSAS) using a combination of static charge sensitive bed and oximetry. Obstructive sleep apnoea syndrome was found in 49 patients, eight patients had borderline sleep disordered breathing (BSDB) and three patients were excluded due to interfering disease. MAIN OUTCOME MEASURES: Patients and controls had an afternoon determination of serum-melatonin. The Epworth Sleepiness Scale was used to score day-time sleepiness. RESULTS: In comparison with normal controls patients suffering from OSAS had significantly higher serum-melatonin levels in the afternoon. However, as a diagnostic test for OSAS in patients with sleep disordered breathing serum-melatonin showed a low sensitivity but a high specificity. The results indicate that breathing disorders during sleep in general affect pineal function. CONCLUSIONS: Sleep disordered breathing seems to disturb pineal function. Determination of afternoon serum-melatonin alone or together with a scoring of daytime sleepiness does not identify OSAS-patients in a heterogeneous population of patients complaining of heavy snoring and excessive daytime sleepiness.

Effect of Breathe Right nasal strip on snoring.

Snoring is a significant problem both for the patient and for the bedpartner. It is well known that nasal stuffiness can contribute to snoring, and sleep quality may deteriorate because of the snoring. Nasal dilation can reduce snoring and improve sleep. Thirty-five habitual snorers (18 female, 17 male) and their bedpartners participated in an open label study. The patients were diagnosed as heavy snorers after they underwent overnight polysomnography showing that their apnoea indexes were below 5, thus sleep apnoea patients were not included in the study. The participants and their partners filled out evaluations concerning snoring intensity, mouth dryness and Epworth Sleepiness Scale prior to and after using Breath Right nasal strips for 14 consecutive nights. The Breathe Right external nasal dilator is a simple, nonpharmaceutical method to decrease nasal airway resistance and thus potentially reduce or eliminate snoring. After using the strips there were statistically significant decreases in snoring (p < 0.001) as graded by the bed partner, and in mouth dryness (p = 0.025) and in the Epworth Sleepiness Scale scores (p = 0.001), as graded by the patient. The results of this study indicate that Breathe Right nasal strips may be used to reduce snoring, mouth dryness and sleepiness in patients presenting with symptoms of snoring.

Occupational exposure to organic solvents and sleep-disordered breathing.

STUDY OBJECTIVE: To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. DESIGN AND PARTICIPANTS: Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. RESULTS: Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. CONCLUSION: The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.