Restless legs syndrome in lung transplant recipients

Given the increased incidence of steroid-induced diabetes and drug-induced anemia, renal dysfunction and neuropathy, we believed that lung transplant recipients would be at an increased risk of developing restless legs syndrome (RLS). We performed a cross-sectional, observational study to determine the prevalence and characteristics of RLS in this population.

Patients filled out two questionnaires during a routine visit: (1) a diagnostic tool for RLS, based on the core clinical features; and (2) a 10-question rating scale used to assess severity. Data were obtained by medical record review with regard to demographics, lung transplant characteristics and known risk factors for RLS.

Forty-two lung transplant recipients (age 46.6 +/- 15.4 years [mean +/- SD]; 24 women, 18 men) without a family history of RLS were recruited. RLS was found in 47.6% (20 of 42) of the patients and 80% had moderate or severe RLS. Seventy-five percent of those with RLS were women (p = 0.03). RLS patients had a serum calcium level that was higher than those without RLS (p = 0.05) and were more likely to be recipient (p = 0.02) or donor positive (p = 0.07) for cytomegalovirus (CMV). All 4 hypothyroid patients on replacement therapy were in the RLS group. The prevalence of diabetes mellitus and chronic renal failure were not significantly different between the RLS and non-RLS groups.

There was a very high prevalence of RLS in our lung transplant population and most patients had moderate or severe symptoms. RLS patients were more likely to be women, donor or recipient positive for CMV, hypothyroid, and to have an elevated serum calcium level.