Ambulatory nocturnal oximetry and sleep questionnaire-based findings in 38 patients with end-stage renal disease.

Background: Patients with end-stage renal diseases (ESRD) have an increased risk of sleep-disordered breathing. With regard to this disorder, controversy persists about prevalence, cost-effective assessment and socio-economical relevance.
Methods: Therefore, we performed, for the first time, overnight ambulatory oximetry in combination with a sleep questionnaire in 38 unselected patients with ESRD and 37 healthy controls. An oxygen desaturation index (ODI) >15, defined as >15 falls in oxygen saturation of > or =4% per h, was observed more frequently in ESRD patients than in healthy controls (47 vs. 3%, P<0.001).
Results: In general, the results derived from the assessment of the Epworth Sleepiness Scale (ESS) as well as those from the visual analogue scale (VAS) did not reflect the ODI values of the respective patient population. Interestingly, 88% of ESRD patients with the questionnaire finding 'excessively loud snoring' had an ODI of >15 as compared with 13% without this complaint (P<0.05). Furthermore, 77% of ESRD patients with a systolic blood pressure >140 mm Hg and a body mass index (BMI) >25, had an ODI of >15. The percentage of ESRD patients with a professional activity was higher in the absence of sleep-disordered breathing (63 vs. 21%, P<0.05).
Conclusion: 'Excessively loud snoring' and a BMI >25 combined with hypertension are risk factors for sleep-disordered breathing in ESRD patients. Nocturnal oxygen desaturations are assessed efficiently by ambulatory oximetry and correlate with relevant biological and socio-economical parameters in ESRD patients.