Abstract
BACKGROUND: We sought to determine the rates and predictors of dietary sodium restriction and to evaluate the reliability of 24-hour urine collection as a tool to estimate dietary sodium intake in heart failure (HF) patients. METHODS AND RESULTS: We evaluated the 24-hour urinary sodium excretion of 305 outpatients with HF and reduced ejection fraction who were educated on following a <2 g sodium diet. The mean sodium excretion according to a single sample from each participant was 3.15 ± 1.58 g, and 23% were adherent to the <2 g recommendation. One hundred sixty-eight participants provided 2 samples with urinary creatinine excretion within normative range. Averaging both resulted in a mean sodium excretion of 3.21 ± 1.20 g and lower adherence rates to the <2-gram diet: 14% versus 23% (P = .019). Multivariate logistic regression showed only male sex and higher body mass index (BMI) to be associated with nonadherence (male: odds ratio [OR] 2.20, 95% confidence interval [CI] 1.25-3.88; 1 unit BMI: OR 1.05, 95% CI 1.01-1.10). Bland-Altman plots of urinary sodium and creatinine showed poor reproducibility between samples. CONCLUSIONS: In this chronic HF population, sodium consumption probably exceeds recommended amounts, particularly in men and those with higher BMI. Urine analyses were not highly reproducible, suggesting variation in both diet and urine collection.