Does salt intake affect the frequency of urination and nocturia?

This study investigated if salt intake has an effect on the frequency of urination during the day and nocturia. They found that high salt intake increases the frequency of urination and nocturia.

Managing salt intake is important for general good health. There is evidence to suggest that salt intake can affect lower urinary tract symptoms (LUTS) such as pollakiuria and nocturia. Pollakiuria is an increased frequency of urination during the day. Nocturia is an increased urge to urinate at night. Patients with LUTS report a reduced quality of life.

High salt intake can lead to excessive urine production. It is unclear if this will also lead to pollakiuria and nocturia.

This study included 728 patients with LUTS. Patients were grouped according to their salt intake – low, medium and high. Medium (average) salt intake was 9.2 grams/day. Blood pressure, LUTS, and quality of life were measured.

Patients with high salt intake had greater pollakiuria (8.4 times/day) compared to the low salt intake group (6.9 times/day). Nocturia symptoms were also more common in the high salt intake group (2.2 times/night) than the low salt intake group (1.4 times/night). Quality of life was significantly lower in patients with a high salt intake.

In patients with a high salt intake, there was a 3.05-times higher risk of worsening of nocturia symptoms. For pollakiuria symptoms, this risk was 2.32 times higher. High blood pressure (hypertension) was also linked to LUTS getting worse. 

This study concluded that high salt intake increases the frequency of urination during the day and nocturia.

This study did not look at sleep patterns or amount of water intake. They also did not know how long patients had been following a low or high salt diet. 

If you have any concerns regarding salt intake and LUTS please discuss this with your physician.