Clue Found to Persistent Bed-wetting
Hormone-Like Substance Linked to Treatment-Resistant Bed-wetting
Dec. 1, 2006 -- Kids who continue to wet the bed even after drug treatment
may have too-high levels of certain hormone-like substances, Danish researchers
The scientists are now studying whether giving kids a drug to block the
substances, called prostaglandins, will work.
Bed-wetting isn't a serious medical condition. But for those who suffer from
it, the humiliating condition can have serious emotional consequences.
While most kids eventually outgrow the problem, as many as one in 10 still
wet the bed at age 7.
The condition also affects up to two in 100 adults.
DDAVP, a prescription drug that reduces urine production, stops most
bed-wetting for 70% of kids. (The drug's generic name is desmopressin.)
Unfortunately, DDAVP doesn't work for 30% of kids.
Why? Konstantinos Kamperis, MD, PhD, and colleagues at Aarhus University
Hospital, Denmark, decided to find out.
They studied 46 7- to 14-year-old boys and girls with treatment-resistant
bed-wetting, and 15 age-matched kids who didn't wet the bed.
All the kids spent two nights in the hospital: The first night to get used
to being there; the second hooked up to blood- and urine-collection
The extensive equipment turned out to be worth the trouble.
Because of obvious difficulties in collecting nighttime urine from kids who
wet the bed, most studies have examined first-morning urine as the closest
substitute. That, Kamperis and colleagues find, is an error.
They found that the big urine differences between bed-wetters and
nonbed-wetters occur in the first few hours of the night. At that time,
treatment-resistant bed-wetters have high levels of sodium, urea, and
prostaglandin in their urine.
It's likely this excess sodium is causing excess urine volume.
But the kids' diets had been controlled before the study, so the problem
wasn't eating salty food.
Instead, Kamperis and colleagues suggest, these kids may have too-high
The researchers are currently studying whether giving the kids indomethacin,
a prostaglandin-blocking nonsteroidal anti-inflammatory drug (NSAID), will
The current study appears in the December issue of the American Journal
of Physiology-Renal Physiology.