Background: Central sleep apnea (CSA) (with or without Cheyne-Stokes breathing) or obstructive sleep apnea (OSA) are common in congestive heart failure (CHF). Correction of anemia may improve CHF. We hypothesized that correction of anemia might also improve sleep-related breathing disorders (SRBDs) in CHF.
Methods: Thirty-eight patients with CHF and anemia (hemoglobin level < 12 g/dL) were treated with erythropoietin and intravenous iron to a target hemoglobin level of 13 g/dL. Home sleep recordings were done before and after 3 months of treatment.
Results: Thirty-seven patients had SRBD (Apnea Hypopnea Index [AHI] of > or = 10). Hemoglobin level increased from 10.4 +/- 0.8 to 12.3 +/- 1.2 g/dL (P < .001). Total AHI values decreased from 35.9 +/- 12.2 to 24.9 +/- 12.2 (P < .001). The AHI of CSA, OSA and Cheyne-Stokes breathing decreased from 26.5 +/- 14.6 to 18.6 +/- 7.7, from 9.4 +/- 10.9 to 6.9 +/- 9.8, and from 13.1 +/- 16.4 to 9.0 +/- 12.2, respectively (all P < .05). Sleep minimal oxygen saturation (SaO2) increased from 62% +/- 12% to 71% +/- 11%; Epworth Sleepiness Scale score improved from 9.4 +/- 6.2 to 6.0 +/- 5.0 and New York Heart Association class improved from 2.9 +/- 0.4 to 1.7 +/- 0.7, all P < .001. Hemoglobin level improvement correlated with improvement in OSA+CSA, CSA, minimal SaO2, Epworth Sleepiness Scale score, and New York Heart Association class (all P < .001).
Conclusion: Improvement of anemia in CHF is associated with a reduction in SRBD and an improvement in daytime sleepiness.