Associations Of Obstructive Sleep Apnea With Renal Function Decline In A Cohort Of Veterans

Association of obstructive sleep apnea (OSA) with accelerated renal function decline was reported in several cohorts of patients with chronic kidney disease (CKD), in which diabetes is highly prevalent. However, in a community-based cohort with low prevalence of diabetes, sleep apnea was associated with slower renal function decline (Canales MT et al., SLEEP 2018). We aim to reconcile these discrepancies by analyzing a sleep clinic-based cohort. We observed 1452 veterans (95% male, 80% white) who were referred to a veteran's sleep medicine clinic and received polysomnography test. Estimated glomerular filtration rate at the baseline (eGFR0) and the end of observation (eGFR1, about five years later) were recorded. A multivariable regression analysis was conducted on the associations of eGFR1 with eGFR0, age, race (black, white, other), hypertension status, diabetes status, and the apnea-hypopnea index (AHI). The baseline prevalences of sleep apnea (AHI >5), diabetes, CKD (eGFR0 <60) were 67%, 36%, 21% respectively. The eGFR1 was positively correlated with eGFR, and negatively correlated with age and with the diabetes status, all with strong significance (P <0.0001). Hypertension status was not correlated with eGFR1 (P =0.5). AHI was negatively correlated with eGFR1 only with marginal significance (P =0.02). When using the subgroup without OSA (AHI <5) as reference, even the subgroup with severe OSA (AHI >30) showed only slightly lower eGFR1 without signifiance (P =0.06). The association of OSA with renal function decline is complex, and the diabetes status is a significant confounding factor. Here we showed that after corrections for age, race and the diabetes status, AHI was only weakly associated with accelerated decline of renal function. Our findings are consistent with the recent findings that mild-moderate OSA may be renally protective, whereas only very severe OSA may be renally impairing. Veterans Affairs Healthcare System