Relationship Between Obstructive Sleep Apnea (OSA) And Chronic Kidney Disease (CKD)

Introduction: Clinic studies have suggested a link between OSA and chronic kidney disease (CKD), but the only population-based study was in older adults (mean age 73 y) and did not show an independent association. We determined the association of OSA, CKD and co-morbidities in a community-based population of middle-aged and older men. Methods: A random sample of men without a previous diagnosis of OSA (n = 837) from the Men Androgens Inflammation Lifestyle Environment and Stress (MAILES) Study (a population cohort) undertook at home 8-channel polysomnography (PSG). Extensive biomedical and questionnaire based assessment of risk factors, and comorbidities occurred. Renal function was classified using the Cockcroft-Gault equation to calculate glomerular filtration rate (GFR, ml/min/1.73 m2). CKD was defined as a GFR < 60 (stage 3). Results: CKD occurred in 3.5% (n = 28) while 21.6% (n = 173) showed a GFR 60–89 (stage 2), similar to National Health Survey figures. Mean age of the cohort was 58 yr (standard deviation = 11). CKD was not significantly associated with OSA (p = 0.59) and occurred in 3.1% (n = 12) of men without OSA [apnoea hypopnea index (AHI) <10] compared with 3.8% (n = 16) in men with OSA (AHI ≥ 10). OSA was present in 57.1% (n = 16) of those with CKD compared to 52.0% (n = 402) of those without CKD. No significant relationship was seen for measures of nocturnal hypoxemia including oxygen desaturation index (ODI) > 16/hr or total sleep with oxygen desaturation <90% (TST90) <4% (75th percentile). When CKD stages were considered, GFR 60–89 was significantly more common in men with OSA [26.6% (n = 111)] than those with no OSA [16.2% (62)]. In multinomial regression analysis adjusted for age and hypertension, OSA was associated with GFR 60–89 [odds ratio (OR), 95% confidence interval (CI)]: 1.6 (1.1–2.3), p = 0.02, but not GFR < 60: 1.1 (0.5–2.4). ODI > 16 and TST90 > 4% showed no significant associations with GFR 60–89. Conclusion: Impaired renal function (GFR 60–89) but not CKD, was associated with OSA, an unselected, community-dwelling sample of middle-aged and older men. The number of men with CKD is a study limitation.