By Amy Norton
NEW YORK (Reuters Health) - A new study finds that one in five U.S. men have to get up at least twice a night to empty their bladders -- which for some could signal an underlying medical problem or even contribute to poorer health.
Known as nocturia, those frequent overnight trips to the bathroom can be a sign of a health condition, ranging from a urinary tract infection to diabetes to chronic heart failure. In men, a benign enlargement of the prostate can also be a cause.
For some people, the constant sleep disruptions can themselves cause problems -- contributing to depression symptoms or, particularly in older adults, falls.
On the other hand, getting up during the night to urinate can also be normal. If you drink a lot of fluids close to bedtime, for example, don't be surprised if your bladder wakes you up at night.
Nocturia also becomes more common with age. Part of that is related to older adults' higher rate of medical conditions. But it could also result from a decrease in bladder capacity that comes with age, explained Dr. Alayne D. Markland, the lead researcher on the new study, which appears in the Journal of Urology.
Her team's findings -- based on a government health study of a nationally representative sample of U.S. adults -- give a clearer picture of just how common nocturia is among men.
The researchers found that among 5,300 U.S. men age 20 and up, 21 percent said that in the past month, they had gotten up at least twice per night to urinate.
Nocturia was more common among African-American men (30 percent) than those of other races and ethnicities (20 percent). Not surprisingly, it also increased with age: Just 8 percent of men ages 20 to 34 reported it, compared with 56 percent of men age 75 or older.
The higher rate among African Americans is one of the more interesting findings from the study, said Markland, of the Birmingham VA Medical Center and the University of Alabama at Birmingham.
The extra risk was not explained by higher rates of medical conditions among black men, or racial disparities in education or income. Future studies, Markland said, should try to uncover the reasons for the higher rate of nocturia among African-American men.
Other factors linked to an increased risk of nocturia included prostate enlargement, a history of prostate cancer, high blood pressure and depression.
It's not entirely clear if all of those problems cause, or result from, nocturia.
With depression, for example, Markland said that poor sleep caused by nocturia could contribute to depression symptoms. On the other hand, men with depression may have sleep problems and be more apt to get up to use the bathroom; in that case, it would not necessarily be a full bladder triggering the trip to the bathroom.
Nocturia can also be a side effect of some medications, such as diuretics used to treat high blood pressure. This study did not have information on men's medication use.
The bottom line for men is that bothersome nocturia is something they should bring up to their doctor, according to Markland.
"I think that someone who is having their sleep disrupted with two or more episodes at night should have it addressed," she said.
If an underlying medical cause, like diabetes, is to blame, then it's important to have that problem treated. In other cases, Markland said, lifestyle changes may do the trick.
"Avoiding caffeine and a large fluid intake at night may help," she noted, as may other lifestyle tactics, like adjusting your sleep habits.
One recent study of 56 older adults with nocturia found that lifestyle changes -- including fluid restriction, limiting any excess hours in bed, moderate daily exercise, and keeping warm while sleeping -- helped more than half of the patients significantly cut down their overnight trips to the bathroom.
There are also medications available specifically for overactive bladder and nocturia. Those include a synthetic version of a hormone that keeps the body from making urine at night, a drug that blocks the ability of the bladder muscles to contract, and antidepressants that make it harder to urinate by increasing tension at the bladder neck.
Several of Markland's colleagues on the study have a financial relationship with companies that market those drugs, including Astellas Pharmaceuticals Inc. and Pfizer Inc.
SOURCE: http://bit.ly/fGZKNN Journal of Urology, online January 19, 2011.