Background: Sleep-disordered breathing (SDB) may increase the risk of cardiovascular disease (CVD) and death in chronic kidney disease (CKD). However, the association between mild reductions in renal function and SDB is uncertain. Methods: We studied 508 community-dwelling men aged ≥67 years (mean 76.0 ± 5.3) who were enrolled at the Minnesota site for the Minneapolis center of the Outcomes of Sleep Disorders in Older Men (MrOS) sleep study and had serum cystatin-C and creatinine measured coincident with overnight polysomnography. CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 using Cockcroft-Gault (CG), modification of diet in renal disease (MDRD) and Mayo Clinic formulae. SDB was defined by a respiratory disturbance index (RDI) ≥15 events/h. Results: Mean cystatin-C was 1.21 ± 0.30 mg/L, and mean creatinine was 1.09 ± 0.23 mg/dL. Median RDI was 7.0 events/h (range 0-73). Higher quartiles of cystatin-C were associated with higher mean RDI (p for trend = 0.007). This association persisted after adjustment for age and race (p for trend = 0.03), but not after adjustment for body mass index (BMI, p for trend = 0.34). After adjusting for age, race, BMI, diabetes, hypertension, and CVD, CKD defined by the Mayo Clinic formula, but not CG or MDRD, was associated with a higher odds of SDB [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.04-3.65, p = 0.04]. Conclusions: Older men with reduced renal function as defined by higher cystatin-C concentration have higher average RDI. This effect is explained by higher BMI in men with higher cystatin-C. CKD defined by the Mayo Clinic formula is independently associated with twofold higher odds for SDB. Therefore, reduced renal function may be associated with SDB in older men.
Bibliographical noteFunding Information:
The Osteoporotic Fractures in Men (MrOS) Study is supported by National Institutes of Health funding. The following institutes provide support: the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the National Institute on Aging (NIA), the National Cancer Institute (NCI), the National Center for Research Resources (NCRR) and NIH Roadmap for Medical Research under the following Grant Nos.: U01 AR45580, U01 AR45614, U01 AR45632, U01 AR45647, U01 AR45654, U01 AR45583, U01 AG18197, U01-AG027810, and UL1 RR024140. The National Heart, Lung, and Blood Institute (NHLBI) provides funding for the MrOS Sleep ancillary study “Outcomes of Sleep Disorders in Older Men” under the following Grant Nos.: R01 HL071194, R01 HL070848, R01 HL070847, R01 HL070842, R01 HL070841, R01 HL070837, R01 HL070838, and R01 HL070839.
Dr. Canales’ time and training was supported by National Institutes of Health funding as well through the National Institute of Diabetes and Digestive and Kidney Diseases, training Grant T32 DK007784. Preliminary data from this analysis were presented in abstract form at the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC in Minneapolis, Minnesota, June 2007 under the title “Reduced Renal Function and Sleep Apnea in Community-Dwelling Elderly Men”.
- Chronic kidney disease
- Kidney dysfunction
- Sleep apnea syndromes
- Sleep disorders
- Sleep-disordered breathing