Abstract 13120: Relationship between Sodium Intake and Sleep Apneain Patients with Heart Failure
Background: Sleep apnea (SA) is common in patients with heart failure (HF). However, the reason for this is unclear. We showed that overnight rostral fluid shift from the legs and degree of fluid retention correlates well with severity of SA in patients with HF. Excessive sodium intake can contribute to fluid retention. We therefore hypothesized that in HF patients, the severity of SA will be related to sodium intake.
Methods: Average daily sodium intake was estimated from two sets of 3-day food records in 123 HF patients, of whom 57 had an overnight sleep study as a part of an epidemiological study. The presence and severity of SA was quantified by frequency of apneas and hypopneas/hr of sleep (apnea-hypopnea index: AHI). Patients were divided into those with an AHI<15 and those with an AHI≥15.
Results: The AHI correlated significantly with sodium intake (r=0.489, P<0.001). Multivariate analysis revealed that the significant independent correlates of higher AHI were male gender, higher sodium intake and higher serum creatinine (r=0.653, p<0.001 for total model). Thirty one of the 57 patients had an AHI≥15, and their sodium intake was higher than in those with an AHI<15 (mean±SD: 3.0±1.2g versus 2.0±0.9g, p=0.001). Receiver operating characteristic analysis revealed that the best cutoff values of sodium intake predicting an AHI≥15 were >2.4g (area under the curve ± standard error, 0.74±0.06, p=0.002, sensitivity 74.2, specificity 73.1).
Conclusions: These findings indicate that in patients with HF, the presence and severity of SA is directly related to the degree of sodium intake, independently of confounders. This relationship is likely due to fluid retention secondary to sodium intake, and to related overnight rostral fluid shift. We conclude that high sodium intake may play a role in the pathogenesis of SA in HF patients, probably by increasing fluid retention. If so, modulation of sodium intake may be a therapeutic strategy to alleviate SA in HF.
- © 2010 by American Heart Association, Inc.