Relationship between sodium intake and sleep apnea in patients with heart failure

Objectives: The purpose of this study was to test the hypothesis that severity of sleep apnea (SA), assessed by frequency of apneas and hypopneas per hour of sleep (apnea-hypopnea index [AHI]), is related to sodium intake in patients with heart failure (HF).

Background: Dependent edema and overnight rostral fluid shift from the legs correlate with the AHI in patients with HF in whom excessive sodium intake can cause fluid retention.

Methods: Sodium intake was estimated by food recordings in 54 HF patients who underwent overnight polysomnography.

Results: Thirty-one of the 54 patients had SA, and their mean sodium intake was higher than that in those without SA (3.0 ± 1.2 g vs. 1.9 ± 0.8 g, p < 0.001). There was a significant correlation between the AHI and sodium intake (r = 0.522, p < 0.001). Multivariate analysis showed that the significant independent correlates of the AHI were sodium intake, male sex, and serum creatinine level.

Conclusions: These findings suggest that in patients with HF, sodium intake plays a role in the pathogenesis of SA.