Insomnia and Relationship With Immunosuppressant Therapy After Lung Transplantation

Lung transplant recipients are at high risk of developing sleep disorders such as insomnia, but the prevalence and features are currently poorly characterized within this population. Since these disorders are associated with increased morbidity and mortality, it is important to identify them to optimize the care of lung transplant recipients. We sought to evaluate the prevalence of insomnia within our university-based lung transplant clinic and determine whether a relationship exists between insomnia and exposure to immunosuppressant medications following transplantation.

Participants were recruited through the University of Wisconsin Hospital and Clinics Lung Transplant Clinic (N = 125). Participants (n = 92) completed the adult sleep history questionnaire, which included the Insomnia Severity Index (ISI) to assess for insomnia (defined as ISI score >10). Cumulative tacrolimus exposure was determined in 73 patients by performing an area under the curve calculation to assess for a potential relationship between tacrolimus exposure and insomnia.

The prevalence of insomnia was 40% within this population. Although no difference in time since transplant was found, cumulative mean ± standard error of the mean tacrolimus exposure was significantly higher in patients with insomnia versus those without insomnia (17 190 ± 1673 ng·d/mL vs 12 130 ± 1630 ng·d/mL, respectively; P = .04). Estimated tacrolimus exposure was not greater with increasing frequency of insomnia complaints (analysis of variance P = .54).

In our population, insomnia is common after lung transplantation, with prevalence greater than the general population. Higher cumulative exposure to tacrolimus may contribute to insomnia in this group. Future research should investigate the relationship between immunosuppressant therapy and development of sleep disorders.