Depressive symptoms are associated with objectively measured sleep parameters in kidney transplant recipients

STUDY OBJECTIVES: Both depression and sleep complaints are very prevalent among kidney transplant (kTx) recipients. However, details of the complex relationship between sleep and depression in this population are not well documented. Thus, we investigated the association between depressive symptoms and sleep macrostructure parameters among prevalent kTx recipients. 

METHODS: Ninety-five kTx recipients participated in the study (54 males, mean age 51 ± 13 y, body mass index 26 ± 4 kg/m2, estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m2). Symptoms of depression were assessed by the Center for Epidemiologic Studies - Depression Scale (CES-D). After 1-night polysomnography each recording was visually scored and sleep macrostructure was analyzed. 

RESULTS: The CES-D score was significantly associated with the amount of stage 2 sleep (r = 0.20, p < 0.05), rapid eye movement (REM) latency (r = 0.21, p < 0.05) and REM percentage (r = -0.24, p < 0.05), but not with the amount of slow wave sleep (r = -0.12, p > 0.05). In multivariable linear regression models the CES-D score was independently associated with the amount of stage 2 sleep (β: 0.205; confidence interval: 0.001-0.409; p = 0.05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; p = 0.05) after adjustment for potential confounders. 

CONCLUSIONS: Depressive symptoms among kTx recipients are associated with increased amount of stage 2 sleep and prolonged REM latency. Further studies are needed to confirm our findings and understand potential clinical implications.