Prevalence of obstructive sleep apnea in patients with chronic kidney disease: a hospital-based study.

Background: Chronic kidney disease (CKD) is has been rising over the past few years, and obstructive sleep apnea (OSA) is a prevalent comorbidity in this population.

Aim: To determine the prevalence of OSA in patients with chronic kidney disease stages I-V and end-stage renal disease (ESRD).

Methods: Patients with CKD of varying grades and ESRD routinely visiting outpatient nephrology clinic or admitted in department of nephrology were included in the study. Stages I-III were categorized as early stages of CKD and stages IV-V and ESRD as late stages of CKD. Patients were categorized into a high risk group based on STOP-BANG and Berlin questionnaires. Patients who were high risk were subjected to in-hospital overnight level III polysomnography. Student's independent t-test and analysis of variance (ANOVA) were employed for the comparison of continuous variables. Chi-square test and Fisher's exact test, as appropriate, were used for the comparison of categorical variables.

Results: Of 111 patients, 46 (41%) were found to have OSA. Of these patients, 15 (33%) had mild OSA (AHI 5-14/h), 13 (28%) had moderate OSA (15-29/h), and 18 (39%) had severe OSA (AHI ≥ 30/h). Overall, 31% of patients in the early stage of CKD and 45% in the late stage were found to have OSA.

Conclusion: This study demonstrated a high prevalence of OSA in patients with CKD when compared to the general population affecting both genders equally. The risk of OSA was higher in the advanced stages of CKD compared to the early stages, and dialysis had no effect on prevalence. Since OSA increases the cardiovascular morbidity in CKD the leading cause of death in these patients, early diagnosis and treatment of OSA may have promise to affect the mortality.