Is there a link between nocturia and high blood pressure at night?

This study investigated if nighttime blood pressure (NBP) is associated with sleep conditions including nocturia (waking up at night to urinate). They found that nocturia is linked to an increased risk of NBP.

Nocturnal blood pressure (NBP) is the term for BP at night. Changes in NBP may be a risk factor for cardiovascular disease (CVD). Everyone will have some variations (10-20%) in BP levels. Less than 10% variation is a ‘non-dipping’ BP pattern. It is unclear what causes NPB changes. Some studies suggest that nocturia may play a role. Nocturia is the term for waking at night to urinate. It can lead to sleep disturbance. This can have a negative effect on quality of life. The relationship between nocturia and NBP is unclear. 

This study included 5959 patients. Patients were asked to measure home BP in the morning and evening. The morning reading was taken immediately after waking. Changes in NBP were calculated using a formula. Breathing patterns were measured using a pulse oximeter (a small device placed on a finger that determines the pulse and the amount of oxygen carried by the body). Patients were also asked to keep a diary of nighttime urinations.

A higher number of nighttime urinations was associated with a smaller nocturnal BP drop (smaller variation). Statistical analysis determined that the number of nocturnal urinations determined if NBP changes occurred. 

The authors concluded that nocturia is linked to an increased risk of NBP.

BP was not measured during sleep. A 24-hour BP monitor can be used for this. More investigation is needed to confirm the findings in this study. 

If you have any concerns regarding nocturia and high BP, please consult with your physician.