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 ± standard devation age 51 ± 13 years, body mass index 26 ± 4 kg/m 2 , estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m 2 ). 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 < .05), rapid eye movement (REM) latency (r = 0.21, P < .05) and REM percentage (r = −0.24, P < .05), but not with the amount of slow wave sleep (r = −0.12, P > .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 = .05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; P = .05) after adjustment for potential confounders.
I NTRO DUCTI O NDepression is one of the most prevalent mental health conditions in patients with chronic kidney disease (CKD) [1][2][3][4] ; furthermore, it is an important determinant of impaired quality of life. 5,6 Among kidney transplant (kTx) recipients, depression is associated with reduced adherence and also with increased morbidity, graft loss, and mortality. [7][8][9][10][11][12][13] Poor sleep and various sleep problems are also frequent complaints among kTx recipients.14,15 Earlier we reported that chronic insomnia was independently associated with the presence of depression in kTx recipients. 16 In the general population there is a strong and bidirectional relationship between depression and sleep.17 This is also reflected in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition definition of major depression (MD), 18 as sleep complaints are core symptoms of MD. Several objective sleep parameters are different in patients with MD than in healthy control patients. Patients with MD have decreased amounts of slow wave sleep (SWS) and shortened rapid eye movement (REM) latency with increased amounts of REM sleep. The exact mechanisms and factors that may link depression to poor clinical outcomes among kTx recipients are not yet well defined. In a recent review focusing on kTx and depression, 23 sleep is not mentioned. This may be due to the complete lack of polysomnography (PSG) studies that assess the association between sleep and depression in this population. The frequent co-occurrence of subjective sleep complaints and depression among kTx recipients 16 suggests that the relationship between the two conditions may be similar to the association described in the g...