Restless Legs Syndrome Following Lung Transplantation: Prevalence and Relationship With Tacrolimus Exposure

Complications following lung transplantation are common and significantly reduce quality of life, and increase morbidity and mortality. Increasing evidence suggests sleep disorders are prevalent following lung transplantation, but factors associated with their development are not known.

We sought to evaluate the prevalence of restless legs syndrome (RLS) in a lung transplant population and determine if a relationship exists between RLS and exposure to immunosuppressant medications.

Subjects were recruited through the University of Wisconsin Hospital and Clinics Lung Transplant Clinic (N = 125). Participants (N = 81) completed sleep questionnaires, including the four RLS diagnostic criteria, insomnia severity index, and Sheehan disability scale. Cumulative tacrolimus exposure was determined in 62 subjects by calculating an area under the curve (AUC) to assess for a relationship with restless legs syndrome.

Prevalence of RLS was 35 percent. Cumulative mean ± SEM tacrolimus exposure was similar in patients with RLS versus those without RLS (17446 ± 1855 ng days/mL vs. 15303 ± 1643 ng days/mL, respectively; p = 0.42). Insomnia severity index scores (12.5 ± 1.0 vs 6.8 ± 0.7, p < 0.0001) and Sheehan disability scores (7.8 ± 1.3 vs 3.6 ± 0.6, p = 0.003) were significantly higher in those with vs those without RLS symptoms, respectively.

Our data confirms increased prevalence of RLS following lung transplantation reported by previous studies. RLS symptoms were not related to estimated tacrolimus exposure. Predictors of RLS following lung transplantation need to be further investigated to better identify and control RLS symptoms and reduce associated insomnia and disability.