Patients with Polycystic Kidney Diseases with Normal Kidney Function Report Poor Sleep Quality

Background: In general, kidney disease has been reported to be associated with poor sleep quality, sleep disturbances, and sleep disorders including obstructive sleep apnea (OSA). While these abnormalities have been reported in CKD population, little is known about sleep characteristics in patients with autosomal dominant polycystic kidney disease (ADPKD), the most common monogenic kidney disorder worldwide. It is possible that aspects unique to ADPKD (increased kidney and liver volumes) may contribute to altered respiratory mechanics that can contribute to sleep abnormalities. These increases in organ volume occur in the setting of normal kidney function. Thus, in this pilot, we examined self-reported sleep characteristics in ADPKD patients with normal kidney function (eGFR > 90 mL/min) compared to a group of BMI, age, and sex matched healthy controls. Methods: ADPKD and matched controls were asked to fill out gold-standard questionnaires that assess aspects of sleep quality (Pittsburgh Sleep Quality Index - PSQI) and risk for the sleep disorder OSA (Stop-Bang). Chronotype was also assessed with the Owl/Lark Questionnaire in all individuals. Results: Seven individuals with PKD (4 women, 3 men) with a mean age of 34 years (± 9.5) and body mass index (BMI) of 30.9 kg/m2 (± 9) were compared to seven matched controls (4 women, 3 men) with a mean age of 32 years (± 8) and a BMI of 34 kg/m2 (± 10). Both groups reported to be morning types with similar scores on the Owl/Lark Questionnaire (PKD: 55.3 ± 11.3 vs Control: 57.5 ± 13.9) and were both at low to intermediate risk for OSA according to the STOP-Bang questionnaire (ADPKD: 1.9 ± 1.1 vs Control: 1.5 ± 0.8). Six ADPKD individuals completed the PSQI, and interestingly, when compared to their six matched controls, ADPKD subjects had significantly higher PSQI ratings than controls (ADPKD: 5.3 ± 1.8 vs Control: 3.7 ± 0.8, p = 0.019) indicating that they had poorer sleep quality. Conclusion: These data suggest that ADPKD individuals may experience poor sleep quality when compared to healthy matched controls, that is not a product of diminished kidney function. The contributions to reduction in sleep quality in ADPKD may be multifactorial including increased abdominal girth due to liver and kidney cyst burden, chronic pain and/or the psychological impact of having a hereditary kidney disorder.