Nighttime Urination Linked to Higher Death Risk
Study Shows Frequent Urination at Night Associated With Increased Mortality Rate
June 1, 2010 (San Francisco) -- Men and women who have to get up two or more times a night to urinate appear to be at an increased risk of death, researchers say.
The increased risk of mortality was seen in all age groups -- 20- to 49 year-olds, 50- to 64-year-olds, and 65- to 90-year-olds -- says Varant Kupelian, PhD, a research scientist at the New England Research Institute in Watertown, Mass.
"Nocturia [defined in the study as having to urinate two or more times a night] is a predictor of mortality, and surprisingly more so in relatively younger men and women, rather than in the elderly," he tells WebMD.
The greater risk of deaths in younger adults "suggests that what we are catching [with frequent night urination] is a marker or warning sign for subclinical disease or for the impending development of chronic disease," he says.
In older adults, falls and fractures that occur when people get up to go to the bathroom in the middle of the night may account for some of the increase in mortality, Kupelian says.
Relationship of Nocturia to Mortality
In the study, Kupelian and colleagues mined data gathered during a large national health survey to determine the relationship of nocturia to mortality. Analyses were conducted on a sample of 15,988 men and women age 20 and older.
Nocturia was assessed using the question: "How many times a night do you usually get up to urinate (pass water)?"
The researchers found that over a nine-year period:
- Men aged 20-40 who woke up two or more times a night to urinate had a 2.56-fold increased risk of dying.
- Women ages 20-29 with nocturia had a 10% increased risk of mortality, but that could have been due to chance.
- Men aged 50-64 with nocturia had a 60% increased risk of dying.
- Women ages 50-64 with nocturia had a 94% increased risk of dying.
- Men aged 65-90 with nocturia had a 49% increased risk of dying.
- Women aged 65-90 with nocturia had a 32% increased risk of dying.
The analysis took into account other factors that can affect mortality, including age, other medical conditions, marital status, body mass index, and smoking.