Poor sleep quality is responsible for the nondipper pattern in hypertensive but not in normotensive chronic kidney disease patients

Aim: This study was designed to evaluate the relationship between sleep quality and hypertension and to determine if there was an association between nondipper blood pressure (BP) and sleep quality in chronic kidney disease (CKD) patients. Methods: A total of 775 pre-dialysis CKD patients (314 normal BP patients, 461 hypertension patients) defined as dippers or nondippers by ambulatory BP monitoringwere recruited for this study. Demographics and clinical correlates were collected, including body mass index, estimated glomerular filtration rate (eGFR) and other measures. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Results: A total of 185 (58.9%) patients with normal BP and 341 (74.0%) hypertensive patients had a nondipper BP pattern. The hypertension group had a higher prevalence of the nondipper BP pattern, smoking, alcohol intake and diabetes mellitus (DM) and lower eGFR levels and poorer sleep quality than the normal BP group. Patients with the nondipper BP pattern had lower haemoglobin, worse renal function and poorer sleep quality when compared with hypertensive CKD patients with the dipping BP pattern. PSQI scores were significantly associated with the rate of nocturnal BP decline (P < 0.05) in the hypertension group but not in the normal BP group. Poor sleep quality was an independent factor affecting BP pattern in hypertensive CKD patients using multivariate linear and logistic regression analyses. There was no association between sleep quality and hypertension in CKD patients after multivariate logistic regression analyses. Conclusion: Poor sleep quality, which is commonly observed in pre-dialysis CKD patients, is an independent associated factor of the nondipper BP pattern in hypertensive CKD patients. No association was found between poor sleep and nondipper BP in normotensive patients.