Background: The relationship between constipation and childhood nocturnal enuresis (NE) has been previously reported; however, this relationship remains controversial. The present study aimed to evaluate the association between constipation and childhood NE.Methods: Data from the Longitudinal Health Insurance Database 2000 (LHID 2000) of Taiwan National Health Insurance Research Database from 2000 to 2013 were collected. A total of 2286 children were enrolled in this study: a case group of 1143 children aged 5–18 years who were diagnosed with NE (NE group) and an age- and sex-matched control group of 1143 children without NE. Conditional logistic regression and odds ratio (OR) for NE were used to examine the association between constipation and childhood NE.Results: The prevalence of NE in the case group (NE group, aged 5–18 years) was 1.03% from 2000 to 2013. The NE group had a higher percentage of constipation in 1 year before the diagnosis of NE. After stratification for sex, both boys and girls with constipation had higher OR for NE. With stratification for age, children aged 5–12 and 7–12 years had a higher OR for NE.Conclusions: Constipation is associated with childhood NE in Taiwan, particularly in children aged 5–7 and 7–12 years.

Congenital nephrogenic diabetes insipidus (CNDI) is a genetic disorder caused by mutations in arginine vasopressin receptor 2 (AVPR2) or aquaporin 2 genes, rendering collecting duct cells insensitive to the peptide hormone arginine vasopressin stimulation for water reabsorption. This study reports a first identified AVPR2 mutation in Taiwan and demonstrates our effort to understand the pathogenesis caused by applying computational structural analysis tools. The CNDI condition of an 8-month-old male patient was confirmed according to symptoms, family history, and DNA sequence analysis. The patient was identified to have a valine 279 deletion–mutation in the AVPR2 gene. Cellular experiments using mutant protein transfected cells revealed that mutated AVPR2 is expressed successfully in cells and localized on cell surfaces. We further analyzed the pathogenesis of the mutation at sub-molecular levels via long-term molecular dynamics (MD) simulations and structural analysis. The MD simulations showed while the structure of the extracellular ligand-binding domain remains unchanged, the mutation alters the direction of dynamic motion of AVPR2 transmembrane helix 6 toward the center of the G-protein binding site, obstructing the binding of G-protein, thus likely disabling downstream signaling. This study demonstrated that the computational approaches can be powerful tools for obtaining valuable information on the pathogenesis induced by mutations in G-protein-coupled receptors. These methods can also be helpful in providing clues on potential therapeutic strategies for CNDI.

Objective: This study aimed to investigate the contribution of high body mass index (BMI) to growth velocity among school-aged children who remained in the same BMI categories for a 6-year period.Methods: This retrospective cohort study included children who enrolled in the school year 2009 and remained in the same BMI categories during their 1st, 4th, and 7th grades (6–7, 9–10, 12–13 years of age). Annual linear growth velocity and weight gain were calculated and compared between sexes, BMI groups, and different times. Risk analysis and repeated measures analysis of variance were performed to identify the impact of BMI on growth velocity.Results: Of the 1,637 subjects, 53.0% were male, and 2.5% and 10.9% belonged to BMI groups of overweight and obese, respectively. In students between 6 and 13 years of age, obesity was associated with higher annual weight gain and height gain. Risk analysis showed that obese subjects had higher linear growth velocity than normal BMI groups of both sexes between 6 and 9 years of age. Unexpectedly, overweight and obese girls between 9 and 13 years of age had less linear growth velocity than underweight girls at the same interval. Repeated measures analysis of variance in both sexes showed a significant statistical association between BMI and different times of growth. However, the effect was less in girls between 9 and 13 years of age.Conclusion: Puberty may dominate over BMI as the main contributor to high growth velocity in girls with underweight BMI emerging into pubertal age.