Both daytime and night-time urinary incontinence may have a genetic component, according to a large new study.
While nocturnal enuresis has been known to be somewhat hereditary, little research had previously linked genes with daytime bladder control.
The new study, published online April 21 in The Journal of Urology, suggests that the odds of a child having severe daytime incontinence is 3 to 10 times greater if either parent had suffered the same.
Dr Alexander von Gontard of Searland University Hospital in Homburg, Germany, and his colleagues studied more than 8,000 British children in the Avon Longitudinal Study of Parents and Children. Parents completed questionnaires about their own daytime and night-time incontinence beyond age 5, and data was obtained from their children at the age of 7-and-a-half.
Overall, 15.5% and 7.8% of the children had nocturnal and daytime incontinence, respectively.
Severe cases of night-time incontinence, defined as 2 or more episodes a week, affected 2.6% of the children. 1% of the children had severe daytime incontinence.
The researchers found significant patterns when they compared rates of incontinence between parents and their children. For a mother or father, having nocturnal incontinence twice a week or more as a child raised the odds of their child having a severe case of the condition by 3.63 and 1.85-fold, respectively (both P < 0.001).
Meanwhile, the odds of a child having severe daytime incontinence was 3.28 times higher if their mother had similar problems as a child (P = 0.005) and 10.1 times higher if their father had grown up with daytime episodes (P < 0.001).
"Their evidence for a familial link for daytime urinary incontinence is a bit more novel than for nocturnal enuresis, but it is not altogether new," Dr John S. Wiener, head of paediatric urology at Duke University Medical Centre, told Reuters Health in an email.
In addition to tying environmental factors to some subgroups of urinary incontinence, for example, previous studies hinted at genetic risks of dysfunctional voiding, giggle incontinence and urge incontinence.
But "many facts regarding the heritability of urinary incontinence are missing", report the researchers.
Dr Wiener, who wasn't involved in the study, also expressed concern over limitations in the study, including the low rate of severe incontinence and the potential for bias among parents attempting to recall their own problems as a child.
"This information does little to help manage such patients," he added. "It may help to tell children that they are not unique in this problem, and, in fact, their parent(s) had the same problem as a child."
Still, he noted that the conditions deserve serious attention, as they can be "embarrassing and distressing problems for children and can negatively impact self-esteem and normal socialisation". (Reuters Health/ May 2011)