Greater sodium excretion linked to elevated BP in African Americans with CKD
Researchers of a published article found that, for African Americans who had both CKD and hypertension, greater urinary sodium excretion was associated with higher blood pressure and larger left ventricular mass.
“We were interested in looking at the relation between sodium and blood pressure in a population that may be particularly sensitive to salt,” Tara I. Chang, MD, MS, of the division of nephrology at Stanford University School of Medicine, told Healio Nephrology. While previous studies have used a single, 24-hour urine collection to estimate sodium intake, she said that a major strength of this analysis — which used data from the African American Study of Kidney Disease and Hypertension — was the availability of multiple, 24-hour urine collections. Mean sodium excretion for all participants included in the analysis was 3.7 grams per day. The association between sodium excretion with blood pressure (systolic and diastolic calculated using 24-hour ambulatory blood pressure [BP] monitoring) and left ventricular mass was evaluated. Cardiovascular outcomes (including hospitalization for myocardial infarction, heart failure, stroke cardiovascular mortality or all-cause mortality) were also considered.
Researchers found that each 1-gram increase in 24-hour sodium excretion was associated with 1.3/0.99 mmHg increase in BP, as well as higher left ventricular mass. No association of sodium excretion with cardiovascular outcomes was observed. Chang argued that future prospective studies need to be conducted to determine “the optimal amount of sodium intake that will improve cardiovascular outcomes.”
Still, she said, “We often counsel our patients with CKD and hypertension to reduce sodium intake; these results help provide some evidence to support our efforts.” – by Melissa J. Webb
Disclosure: Chang reports receiving consulting fees from Janssen, Novo Nordisk and Fresenius.