High salt intake is known to be the most pivotal environmental factor in the pathogenesis of hypertension. However, the association of high sodium intake with central hemodynamics in hypertensive individuals has not been well defined. Here, we determined the association of estimated 24-h urine sodium and potassium excretion estimated from a spot urine analysis with parameters of central pulse wave analysis in 515 hypertensive individuals.
Fasting spot urine samples were obtained in the early morning after the first void, and estimated 24-h urine sodium and potassium excretion were estimated from measurement of urine sodium, potassium and creatinine. Central hemodynamics and arterial stiffness parameters were assessed via pulse wave analysis of the radial artery.
The estimated 24-h sodium and potassium excretion values were 150 ± 40 and 49 ± 10 mEq, respectively. There was a step-wise decrease in pulse pressure amplification with increasing estimated 24-h urine sodium excretion. Multiple linear regression analyses revealed that both estimated 24-h urine sodium excretion and sodium/potassium ratio were independently associated with increases in central pulse pressure, augmented aortic pressure and augmentation index and were inversely associated with pulse pressure amplification.
The estimated 24-h urinary sodium excretion is independently associated with central hemodynamics. This may provide the basis for prospective interventional studies of epidemiologic scale to determine the potential beneficial effects of reduced salt consumption on central hemodynamics.