The condition, which has several possible causes, leads to lack of sleep for sufferers, which in turn can have other implications, including an increase in stress, irritability or tiredness, and a significant negative impact on quality of life.
The new research, to be presented at the European Association of Urology Congress in London in March 2017, was carried out by a team of researchers from Nagasaki University in Japan, a country which tends to have a higher than average salt intake.
The team recruited 321 Japanese men and women who had both trouble sleeping and a high salt intake.
Participants were given guidance and support to reduce salt consumption, and followed for a 12-week period.
Of the 321 participants, 223 managed to reduce their salt intake from 10.7g per day to 8g/day.
The average night-time frequency of urination in this group decreased, dropping from 2.3 times/night to 1.4 times; Daytime urination also reduced.
In contrast, when 98 subjects increased their average salt intake from 9.6 g/night to 11g/night, their need to urinate also increased, from 2.3 times/night to 2.7 times/night.
The team also found that those whose nightly bathroom visits decreased also benefited from a marked improvement in the quality of life.
Commenting on the findings, lead researcher Dr Matsuo Tomohiro said, “This is the first study to measure how salt intake affects the frequency of going to the bathroom, so we need to confirm the work with larger studies. Night-time urination is a real problem for many people, especially as they get older. This work holds out the possibility that a simply dietary modification might significantly improve the quality of life for many people.”
Dr Marcus Drake from the Working Group for the EAU Guidelines Office Initiative on Nocturia added, “Research generally focusses on reducing the amount of water a patient drinks, and the salt intake is generally not considered. Here we have a useful study showing how we need to consider all influences to get the best chance of improving the symptom.”