Purpose: Sleep-disordered breathing(SDB) may be deleterious to the cardiovascular system and other organs, including the kidney. Although older men are at increased risk for both kidney disease and SDB, it is unknown whether SDB is associated with higher urinary albumin excretion in this population. Methods: We examined 507 community-dwelling men age≥67 years(mean 76.0±5.3) enrolled in the MrOS Sleep study who underwent overnight polysomnography and gave a spot urine sample. SDB severity was categorized using the respiratory disturbance index and percent total sleep time <90% oxygen saturation (%time O2<90). Urinary albumin excretion was expressed using the albumin-to-creatinine ratio(ACR). Results: There was a graded association between respiratory disturbance index and ACR (age- and race-adjusted mean ACR=9.35 mg/gCr for respiratory disturbance index≥30 versus 6.72 mg/gCr for respiratory disturbance index<5, p=0.007). This association was attenuated after further adjustment for body mass index (BMI), hypertension and diabetes and no longer reached significance (p=0.129). However, even after adjustment for age, race, BMI, hypertension, and diabetes, greater %time O2<90 was associated with higher ACR (10.35 mg/gCr for ≥10%time O2<90 versus 7.45 mg/gCr for <1%time O2<90, p=0.046). Conclusion: SDB, measured by elevated respiratory disturbance index or nocturnal hypoxemia, was associated with higher ACR. The relationship between respiratory disturbance index and ACR was partially explained by higher BMI and greater prevalence of hypertension and diabetes among men with SDB. However, greater nocturnal hypoxemia was independently associated with higher ACR, suggesting that the hypoxia component of SDB may mediate any detrimental effect of SDB on the kidney.
Bibliographical noteFunding Information:
Dr. Canales’ time and training partially supported by National Institutes of Health funding through the National Institute of Diabetes and Digestive and Kidney Diseases training grant T32 DK007784.
This study was funded by 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 numbers: R01 HL071194, R01 HL070848, R01 HL070847, R01 HL070842, R01 HL070841, R01 HL070837, R01 HL070838, and R01 HL070839. The Minnesota Center is funded under grant number: R01 HL070847. The funding institute had no role in the collection, analysis, or interpretation of the data or in the decision to submit the paper for publication.
- Chronic kidney disease
- Nocturnal hypoxemia
- Sleep-disordered breathing