Prevalence of Sleep Apnea and its Associated Factors in Chronic Kidney Disease Patients

This study aimed to determine the prevalence of sleep apnea and its associated factors in patients with chronic kidney disease (CKD).
This population-based cross-sectional study included 47 CKD patients, referred to the dialysis unit of Kosar Hospital in Semnan, Iran, in 2017. Two questionnaires were used for data collection. The first questionnaire included demographic and clinical variables, and the second questionnaire (STOP-BANG questionnaire) was used to measure sleep apnea in CKD patients. Also, the Apnea-Hypopnea Index (AHI) was calculated for all patients and was considered as the gold standard. To determine the factors associated with sleep apnea, univariate and multiple logistic regression models were used. Finally, the area under the receiver operating characteristic curve (ROC) was determined for assessing the discriminative ability of the model, as well as the accuracy of STOP-BANG questionnaire. STATA version 14 was used for data analysis.
The prevalence of sleep apnea in CKD patients was 53.2%. Also, its prevalence in women and men was 52% and 48%, respectively. In the multiple logistic regression model, body mass index (BMI) (OR: 1.21, 95% CI: 1.04-1.31) and blood urea nitrogen (BUN) (OR: 0.94, 95% CI: 0.91-0.98) had significant associations with sleep apnea in CKD patients; the area under the ROC curve was 0.7982 for this model. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the ROC curve of STOP-BANG questionnaire for AHI≥15 were 71.43, 61.54, 60, 72.73, and 0.6932, respectively.
This study showed that the prevalence of sleep apnea in CKD patients was high. Given the acceptable validity of STOP-BANG questionnaire, this scale can be used to screen sleep apnea in CKD patients.