Bone age and probable aetiological causes in primary nocturnal enuresis

To investigate probable aetiological risk factors and to identify whether there are any differences in bone age between normal children and children with primary nocturnal enuresis (PNE).

Ninety children with primary nocturnal enuresis and 40 healthy children were included in the study. Enrolment began in January 2001, and continued through July 2002. Data were obtained via consultation with children and their families, physical examination and laboratory findings. Left hand and wrist graphs of each patient were acquired, and, using Tanner Whitehouse charts (TW-2), bone ages were determined via comparison of 20 hand and wrist bones.

Of the total of 90 children with primary nocturnal enuresis participating in the study, 52 (57.8%) were male and 38 (42.2%) were female. Of the control group, 24 (60%) were male and 16 (40%) were female. Differences between chronological ages and bone ages of the PNE and control groups were 0.57+/-0.59 and 0.54+/-0.67 y, respectively, and no significant difference was seen (p = 0.484). In 90% of the children in the PNE group there was found to be a primary nocturnal enuresis history in the family, whereas in the control group this rate was only 7.5%. Of the children with PNE, 62.2% had very deep sleeping habits, while 7.5% of the control group had this problem.

Our study provides no evidence that bone ages of children suffering from PNE are lower than normal children. We found that a family history of enuresis, male sex and difficulty in waking were risk factors in primary nocturnal enuresis.