Nocturnal hypoxemia: a neglected cardiovascular risk factor in end-stage renal disease?

Its is well established that sleep apnea (SA) is a health problem of paramount importance because it disrupts sleep and quality of life and may induce serious neuroendocrine and cardiovascular complications. There is little doubt that chronic renal failure is an independent cause of SA. The hypothesis that SA may depend on the accumulation of endogenous opioids still remains to be tested. Cytokines, particularly TNF-alpha and IL-6 which are much elevated in end-stage renal disease (ESRD), may also be implicated in the pathogenesis of SA. Nocturnal hypoxemia is an independent predictor of cardiovascular events in ESRD and the prediction power of this parameter remains strong and substantially unmodified after statistical adjustment for established cardiovascular risk factors in the dialysis population. Left ventricular hypertrophy and dysautonomia appear to be most likely intermediate mechanisms mediating the adverse cardiovascular effects of SA in ESRD.