Association of sleep-related problems with CKD in the United States, 2005-2008

Abstract

Background: Sleep-related problems, which have been associated with poor health outcomes, have not been investigated thoroughly in people with chronic kidney disease (CKD). We examined the prevalence of a variety of sleep-related problems in persons with and without CKD.

Study design: National cross-sectional survey (National Health and Nutrition Examination Survey 2005-2008).

Setting & participants: Community-based survey of 9,110 noninstitutionalized US civilian residents 20 years or older.

Predictor: CKD, defined as estimated glomerular filtration rate (eGFR) of 15-59 mL/min/1.73 m(2) (stages 3 and 4) or eGFR ≥60 mL/min/1.73 m(2) and albumin-creatinine ratio ≥30 mg/g (stages 1 and 2).

Outcome: Sleep quality, defined using self-report in a multi-item sleep questionnaire including items from previously validated instruments.

Measurements: Albuminuria and eGFR assessed from urine and blood samples; sleep, demographics, and comorbid conditions assessed using a standardized questionnaire.

Results: Inadequate sleep (≤6 hours per night) differed by CKD severity (37.4%, 43.0%, and 30.9% for no CKD, CKD stages 1 and 2, and CKD stages 3 and 4, respectively; P = 0.003). Frequent sleeping pill use (8.4%, 9.9%, and 16.6%), leg symptoms (39.2%, 48.0%, and 50.9%), and nocturia (20.9%, 35.2%, and 43.6%; P < 0.001 for all) also differed by CKD severity. After adjustment for age, sex, race/ethnicity, obesity, diabetes, and cardiovascular disease, the prevalence of these sleep-related problems remained higher in people with CKD stages 1 and 2 relative to no CKD. Most other measures of sleep quality, disorder, and functional outcomes did not differ by CKD.

Limitations: Inability to establish causality and possible unmeasured confounding.

Conclusion: Providers should be aware of early sleep-related CKD manifestations, including inadequate sleep, leg symptoms, and nocturia, and of the high rate of reported sleep medication use in this population.