Sleep quality in renal transplant patients: a never investigated problem

Despite the great prevalence of sleep disorders and the low quality of sleep in patients with renal diseases, to date no study has evaluated these problems in renal transplant patients.The aim of the study was to assess sleep quality (SQ) in 301 kidney graft recipients by the Pittsburgh Sleep Quality Index (PSQI, range 0-21, with higher scores indicating worse SQ), in comparison with PSQI of both patients on haemodialysis (HD) (n = 245) and normal control subjects (n = 169).PSQI of renal transplant patients averaged 6.46+/-3.71, a value significantly lower than in HD patients (8.52+/-3.81, P0.001), but higher than in control subjects (3.54+/-1.61, P0.0001 vs both transplant and dialysis patients). No correlation was found between PSQI and the main biochemical parameters of transplant patients. When the patients were divided into 'good' (PSQI5) or 'poor' (PSQI5) sleepers, a significant risk of psychological problems was associated with the condition of 'poor sleeper' (OR: 2.3; P0.02), with no further correlation detected in either of the two groups.These data demonstrate that SQ in renal transplant patients is surprisingly low, despite a well preserved renal function, and that poor sleep in these patients is also secondary to psychological problems. The use of PSQI in such patients represents a useful tool for the investigation of SQ and quality of life.