Sleep‐disordered breathing, brain volume, and cognition in older individuals with heart failure

BACKGROUND AND PURPOSE: Sleep‐disordered breathing is common in individuals with heart failure and may contribute to changes in the brain and decreased cognition. However, limited research has explored how the apnea‐hypopnea index contributes to brain structure and cognition in this population. The aims of this study were to explore how the apnea‐hypopnea index is associated with brain volume and cognition in heart failure patients. METHODS: Data of 28 heart failure patients (mean age = 67.93; SD = 5.78) were analyzed for this cross‐sectional observational study. We evaluated the apnea‐hypopnea index using a portable multichannel sleep‐monitoring device. All participants were scanned using 3.0 Tesla magnetic resonance imaging and neuropsychological tests. Brain volume was evaluated using a voxel‐based morphometry method with T1‐weighted images. We used multiple regressions to analyze how the apnea‐hypopnea index is associated with brain volume and cognition. RESULTS: We found an inverse association between apnea‐hypopnea index scores and white matter volume (β = −0.002, p = 0.026), but not in gray matter volume (β = −0.001, p = 0.237). Higher apnea‐hypopnea index was associated with reduced regional gray and white matter volume (p < 0.001, uncorrected). Cognitive scores were not associated with the apnea‐hypopnea index (p‐values were >0.05). CONCLUSION: Findings from this study provide exploratory evidence that higher apnea‐hypopnea index may be associated with greater brain volume reduction in heart failure patients. Future studies are needed to establish the relationship between sleep‐disordered breathing, brain volume, and cognition in heart failure samples.