Major Sleep Disorders Among Women

(Women's Health Series)

Sadeka Tamanna, MD, MPH; Stephen A. Geraci, MD


South Med J. 2013;106(8):470-478. 

In This Article

Restless Leg Syndrome

This movement disorder is characterized by an urge to move the legs, typically during rest, which is relieved by activity. Symptoms are often accompanied by sensations of "creeping," "pulling," "itching," or "tingling," and the diagnosis requires the presence of sensory symptoms.[58] The International Restless Leg Syndrome Study Group developed standardized criteria for the diagnosis of RLS (Fig. 3),[12] which were modified by a consensus conference in 2002 (Fig. 4).[58] The prevalence ranges from 4% to 29% in the general population[59,60] and increases with age. Prospective cohort data suggest that 11.7% of women are affected,[61] and overall prevalence is higher among women (13.9%) than men (6.1%) in another cohort analysis.[62] Although 80% of patients with RLS will have nocturnal periodic limb movements, many patients with these abnormal movements do not have RLS. Periodic limb movements are characterized by episodic repetitive, highly stereotyped limb movements that occur during sleep and by resulting clinical sleep disturbances that cannot be explained by another sleep disorder.[10] Although periodic limb movements may be observed during polysomnography in patients with RLS, the diagnosis is made on the basis of clinical symptoms (Fig. 4) and a sleep study is not necessary.

Figure 3.

International Classification of Sleep Disorders-2 restless leg syndrome diagnostic criteria.12

Figure 4.

International Restless Leg Syndrome Study Group criteria for restless leg syndrome. Adapted with permission from the American Academy of Sleep Medicine.58

Although the mechanism of this disease is unknown, dopaminergic dysfunction is thought to be an underlying component.[63–65] The current consensus theory on the pathophysiology of RLS is the "iron dopamine hypothesis." Iron is a cofactor for the enzyme tyrosine hydroxylase, which performs a rate-limiting enzymatic step in the formation of dopamine. Patients with RLS show a greater circadian variation of dopamine metabolites, consistent with the circadian (evening concentrated) symptom clustering in this disorder.[44]

In addition to reducing quality of life, RLS may predispose to significant morbidity and excess mortality. A positive correlation between RLS and coronary artery disease was found in a large number of women (n = 70,694) in a prospective study. Women with RLS for ≥3 years demonstrated an elevated risk for nonfatal myocardial infarction and fatal coronary heart diseases.[66]

Iron-deficiency anemia, pregnancy, smoking, neuropathy, rheumatoid arthritis, multiple sclerosis, diabetes, kidney disease, caffeine and alcohol consumption, and use of H2-receptor blockers and some antidepressant medications have been linked to RLS.[44,63] In a cohort study of women studied during and after pregnancy, 26% were found to have RLS during pregnancy (with symptoms being most common during the third trimester), which tended to disappear after delivery. Affected women had lower hemoglobin concentrations compared with nonaffected women,[67] supporting the theory that iron status may contribute to RLS.

The treatment of RLS is multimodal. The American Academy of Sleep Medicine developed recommendations for pharmacotherapy.[45,68] A treatment algorithm (Fig. 5) describes an organized strategy.[68] Avoidance of certain foods (eg, caffeine, alcohol) and drugs (eg, antihistamines, neuroleptics, some dopamine antagonists) can be helpful. Selective serotonin receptor blockers, tricyclic antidepressants, and lithium may worsen RLS symptoms and also should be avoided whenever possible.[69]

Figure 5.

Treatment of restless leg syndrome (RLS) and periodic leg movement. BzRA, benzodiazepine receptor agonist.44,68

RLS often is underdiagnosed. In a large multinational primary care population of 23,052 patients, 68% of women had RLS; however, only 12.9% received the diagnosis, despite 64.8% reporting their RLS symptoms to a physician. Published data on women with RLS are few and more research focusing on the symptoms and treatment options for women is needed to tailor both diagnostic and treatment strategies.[60]