Objective: To evaluate the prevalence of sleep disorders in patients awaiting kidney transplants compared to a control group.
Patients and methods: We carried out an observational study of 23 patients on a kidney transplant waiting list in comparison with 20 healthy volunteers matched for age, sex, and body mass index (BMI). Overnight polysomnography was performed and a diagnosis of sleep apnea-hypopnea syndrome (SAHS) established when the apnea-hypopnea index (AHI) was 10 or higher.
Results: Eighty-two percent of the patients awaiting kidney transplants (16 men and 7 women with a mean [SD] age of 51 [15] years and a mean BMI of 25 [3.8] kg/m2) had some type of sleep disorder. The most frequent disorders were SAHS (48%) and insomnia and periodic limb movement disorder (30%). Patients showed poorer sleep efficiency compared to the control group (75.4% vs 87.8%; P=.01) and a lower percentage of slow-wave and rapid eye movement sleep (24.5% vs 40%; P=.001). Those with sleep-disordered breathing had a higher AHI (17.7 vs 3.6; P=.001) and oxygen desaturation index (31.5 compared to 8.2; P=.001).
Conclusions: Sleep disorders are common in patients awaiting kidney transplants. Such patients show reduced quantity and quality of sleep compared to controls and a significantly elevated number of respiratory events that may affect morbidity and mortality.