Sleep quality, fatigue, societal participation and health-related quality of life in kidney transplant recipients: a cross-sectional and longitudinal cohort study

Background. Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep. Methods. Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire. Individual strength (i.e. a composite of fatigue, concentration, motivation and physical activity), societal participation and HRQoL were assessed using validated questionnaires. Results. We included 872 KTR (39% female, age 56 +/- 13 years) and 335 healthy controls. In total, 33% of male KTR and 49% of female KTR reported poor sleep quality, which was higher compared with male and female healthy controls (19% and 28%, respectively, P <.001 for both). In logistic regression analyses, female sex, anxiety, active smoking, low protein intake, physically inactive lifestyle, low plasma magnesium concentration, using calcineurin inhibitors, not using mTOR inhibitors and using benzodiazepine agonists were associated with poor sleep quality. In adjusted linear regression analyses, poor sleep was strongly and independently associated with lower individual strength [standardized beta(st.beta) = 0.59, 95% confidence interval (CI) 0.45 to 0.74, P <.001], poorer societal participation (frequency: st.beta= -0.17, 95% CI -0.32 to -0.01, P =.04; restrictions: st.beta= -0.36, 95% CI -0.51 to -0.21, P <.001; satisfaction: st.beta= -0.44, 95% CI -0.59 to -0.28, P <.001) and lower HRQoL (physical: st.beta= -0.53, 95% CI -0.68 to -0.38, P <.001; mental: st.beta= -0.64, 95% CI -0.78 to -0.50, P <.001). The associations with poorer societal participation and lower HRQoL were strongly mediated by individual strength (P <.001 for all), yet the suggested direct effects of poor sleep quality on HRQoL remained significant (P-physical =.03, P-mental = .002). Longitudinal data of 292 KTR showed that sleep quality improves after kidney transplantation in males (P <.001), but not in females (P = .9). Conclusions. Poor sleep quality is common among KTR, and may be a potential target to improve fatigue, societal participation and HRQoL among KTR.