No relationship between family history of enuresis and response to desmopressin.

PURPOSE: We determined the prevalence of positive family history of nocturnal enuresis in relation to response to desmopressin. MATERIALS AND METHODS: A total of 328 children with nocturnal enuresis and 53 normal children were interviewed to determine the presence of family history of nocturnal enuresis. Response to desmopressin was confirmed in some cases by home recordings of enuresis episodes during 2 baseline weeks and 2 weeks of 20 to 40 microg. desmopressin intranasally. RESULTS: Significantly more patients than normal children (75% versus 38%, p <0.001) reported a positive family history of enuresis (any relative). The high prevalence of a positive family history of nocturnal enuresis was present in severe/nonsevere or primary/secondary types of enuresis. Of the patients 141 completed 4 weeks of home recordings including 20 with a complete response (greater than 90% reduction in wet nights week), 25 with a partial response (50% to 90% reduction) and 96 with no response (less than 50% reduction). The prevalence of a positive family history (any relative) was no different among the response groups (80%, 84% and 78%, respectively). Similarly, family history, as defined by first order relatives only, showed no relation to treatment response. CONCLUSIONS: A positive family history of nocturnal enuresis is more prevalent in patients with enuresis than in normal children regardless of the nature of the nocturnal enuresis. In contrast to previous reports, a positive family history failed to predict a good response to desmopressin treatment. Hereditary factors are important to consider in desmopressin responding and desmopressin resistant cases.

Intra-individual variability in nighttime urine production and functional bladder capacity estimated by home recordings in patients with nocturnal enuresis.

PURPOSE: We evaluated the intra-individual variability and reproducibility of nighttime urine production on wet nights and functional bladder capacity estimated by long-term home recordings of monosymptomatic nocturnal enuresis. In particular, the intention was to evaluate the validity of 1 versus 2 weeks of recording when estimating urine volume on wet nights and 1 versus 2 weekends of recording when estimating functional bladder capacity. MATERIALS AND METHODS: We analyzed 120, 2-week home recordings of nighttime urine volume from patients with monosymptomatic nocturnal enuresis 6 to 16 years old (mean age 9.1) with at least 3 wet nights per week. Most patients were nonresponders or partial responders to desmopressin. Nighttime urine volume was estimated by weighing diapers before and after sleep, and measuring morning urine volume. Of the home recordings 62 included frequency volume charts for 2 weekends, which were evaluated for functional bladder capacity defined as the largest voided volume observed. RESULTS: No significant overall week-to-week differences were observed in average urine volume on wet nights and functional bladder capacity. There was a large intra-individual variability in all measured variables, which was most pronounced for functional bladder capacity and least pronounced for urine volume on wet nights. With regard to repeatability, the limits of agreement of urine volume on wet nights were -32% and 36% (95% confidence interval) as opposed to -54% and 48% for functional bladder capacity. CONCLUSIONS: In this study intra-individual week-to-week estimates of average urine volume on wet nights demonstrated acceptable variability and repeatability in contrast to functional bladder capacity. A reliable estimate of urine volume on wet nights could be obtained by 7 nights of home recording, whereas 4 days of daytime recording were necessary when estimating functional bladder capacity. Similar studies of patients who respond to desmopressin are needed.

The effect of the full bladder on vasopressin secretion in healthy young adults.

Interactions between the central nervous system, bladder and kidneys have been investigated for many years in animal studies and have shown that bladder distension, in animals, leads to decreased urine production. The objectives of the current study were to determine the effect of a full bladder on urinary output, vasopressin secretion and urine osmolality in humans. The study involved healthy volunteers. They were studied for a period of 48 hours. This period included two 24-hour studies, one involving regular and frequent voidings (to produce a minimal bladder filling) and the other voiding postponement (to produce maximal bladder distension). In contrast to enuresis studies a circadian rhythm of vasopressin secretion was observed in the males involved in this study, whereas no significant rhythm of vasopressin secretion could be detected in the female subjects. However, this study was unable to confirm that, in humans, a full bladder causes a decrease in urine production, an increase in vasopressin secretion or an increase in urine osmolality.