Reducing sodium intake may provide benefits to health of kidney and heart among the patients with chronic kidney disease, a new study has claimed. Urinary excretion of proteins, including albumin, is a hallmark of chronic kidney disease (CKD). Therapies that reduce such albuminuria can slow kidney function decline and also have beneficial effects on the heart and blood vessels.
Currently available therapies do not eliminate albuminuria in many patients, leaving these individuals with what is known as residual albuminuria. Researchers led by Martin de Borst from University Medical Centre Groningen in the Netherlands, studied two interventions that have demonstrated potential for reducing residual albuminuria: dietary sodium restriction and a drug (paricalcitol) that activates the vitamin D receptor.
In a randomised trial that included 45 patients with CKD, each intervention was added to an optimised conventional treatment regimen during four 8-week periods. The researchers found that dietary sodium restriction led to a significant reduction of residual albuminuria and blood pressure, whereas paricalcitol had no significant effect on these measures.
The combination of paricalcitol and a low sodium diet, however, resulted in the lowest albuminuria levels. “What we found was that sodium restriction provided a relatively large beneficial effect, whereas the effect of paricalcitol was small,” said de Borst. “Thus, the impact of the combined intervention was largely due to the protective effect of sodium restriction,” he said.
Most people consume twice as much sodium as the two grammes per day recommended by the World Health Organisation. “In our study, patients consumed on average four grammes of sodium per day, which is well in line with global trends in sodium consumption among CKD patients,” said de Borst. “Interestingly, following our intervention aimed at reduced sodium intake, patients consumed 2.5 grammes per day, which is still above the recommended level,” he said.
“This moderate restriction resulted in a strong reduction in albuminuria and blood pressure, indicating that even a moderate reduction in sodium intake may provide serious health benefits,” he added. The study appears in the Journal of the American Society of Nephrology (JASN).