Sleep Disturbance and Myocardial Damage in Patients with End-Stage Renal Disease

Jung, Hae Hyuk; Lee, Jung Hie

Abstract

BACKGROUND
Recently, it was suggested that sleep disorders, like sleep apnea and periodic limb movements during sleep, are associated with the cardiovascular complications and outcomes seen in ESRD patients. This study investigated the association between sleep disturbances, including nocturnal hypoxemia, and myocardial damage in ESRD patients. METHODS: We conducted a cross-sectional study of 15 hemodialysis patients (age=50+-8 years, M: F= 11: 4, diabetes=6) who were classified as at high risk of sleep disturbance using the Epworth Sleepiness Scale and Sleep Disorders Questionnaire. Overnight polysomnographic studies were performed in these 15 patients to evaluate sleep parameters. The predialysis serum concentration of cardiac troponin T (cTnT) was measured as a marker of myocardial damage. RESULTS: Apnea+hypopnea index >5, which is a diagnostic criterion of sleep-related breathing disorder, was found in 12 (80%) patients. Several sleep parameters were associated with cTnT concentration. Sleep efficiency and lowest oxygen saturation decreased (p<0.05 and p=0.06, respectively), and average desaturation increased (p<0.05) with increasing cTnT concentration. Spearman's Rho, which was used to assess the relationships between the severity of sleep apnea and clinical parameters, showed that apnea+hypopnea index and oxygen desaturation index were negatively correlated (both p<0.01) with the serum concentration of uric acid. In multivariate analysis, the uric acid concentration was also independently associated with apnea+hypopnea index and oxygen desaturation index. CONCLUSION: Elevated concentration of cTnT was associated with poor sleep efficiency and severe oxygen desaturation during sleep, and the serum concentration of uric acid was lower in patients with severe sleep apnea.