Correlation between increased urinary sodium excretion and decreased left ventricular diastolic function in patients with type 2 diabetes mellitus

Abstract

Background: Increased salt intake may induce hypertension, lead to cardiac hypertrophy, and exacerbate heart failure. When elderly patients develop heart failure, diastolic dysfunction is often observed, although the ejection fraction has decreased. Diabetes mellitus (DM) is an established risk factor for heart failure. However, little is known about the relationship between cardiac function and urinary sodium excretion (U-Na) in patients with DM. Methods: Wemeasured 24-hour U-Na; cardiac functionwas evaluated directly during coronary catheterization in type 2 DM (n=46) or non-DM (n=55) patients with preserved cardiac systolic function (ejection fraction ≥60%). Cardiac diastolic and systolic function was evaluated as -dp/dt and +dp/dt, respectively. Results: The average of U-Na was 166.6 ± 61.2 mEq/24 hour (mean ± SD). In all patients, stepwise multivariate regression analysis revealed that -dp/dt had a negative correlation with serum B-type natriuretic peptide (BNP; β = -0.23, P = .021) and U-Na (β = -0.24, P = .013). On the other hand, +dp/dt negatively correlated with BNP (β = -0.30, P