Kidney patients may gain from less salt
UQ School of Human Movement Studies PhD student Emma McMahon monitored 20 people with chronic kidney disease on a high-salt diet and 20 on a low-salt diet.
The high-salt diet consisted of 4600 milligrams of sodium per day for two weeks and the low-salt diet consisted of 1800 milligrams of sodium per day for two weeks.
Mrs McMahon said the study measured various factors related to heart and kidney health, including change in body fluid volume, blood pressure, and protein in the urine.
"We found that low salt intake reduced excess extracellular body fluid, a risk marker for heart disease and worsening kidney health, by 1 litre, on average," Ms McMahon said.
"It also lowered blood pressure by 10/4 millimetres of mercury (mm Hg), and cut protein excretion in the urine by half, without causing significant side effects.
"These are clinically significant findings, with this magnitude of blood pressure reduction comparable to that expected with the addition of blood-pressure lowering medication.
These effects are larger than what you would expect in people without chronic kidney disease," she said.
Principal investigator Dr Katrina Campbell said the study found that salt restriction could be an inexpensive, low-risk and effective way to reduce heart and kidney risk in patients with chronic kidney disease.
The study is scheduled for publication in the Journal of the American Society of Nephrology.