Relationship between inflammatory biomarkers and sleep-disordered breathing in patients with heart failure

Inflammation activation is associated with adverse outcomes in patients with heart failure (HF). Sleep-disordered breathing (SDB) observed in 50% of patients with HF worsens the clinical outcome of HF, possibly through the exacerbation of inflammation. However, data on inflammation activation related to SDB are limited in patients with HF. We investigated the relationship between SDB severity and serum levels of C-reactive protein (CRP) and tumor necrotic factor (TNF)-α in HF patients with systolic dysfunction. Nineteen patients with HF were enrolled (mean age, 67.3 years; 16 men; mean ejection fraction, 33.6%). No significant correlation was observed between log-transformed CRP level and apnea–hypopnea index (AHI). In univariable analysis for serum CRP level, the percentage of rapid eye movement (REM) sleep per total sleep time was the only significant factor. The lower the percentage of REM sleep, the higher was the CRP level (coefficient, − 0.474; P = 0.047). In contrast, the serum TNF-α level was significantly correlated with age, ischemic etiology, diabetes mellitus, estimated glomerular filtration rate (eGFR), and AHI. In multivariable analysis, eGFR (coefficient, − 0.486; P = 0.017) and AHI (coefficient, 0.399; P = 0.044) significantly and independently correlated with TNF-α level. The severity of SDB expressed as AHI was directly related to the circulating level of TNF-α, but not circulating CRP level, in HF patients with systolic dysfunction.