Differences in the urinary metabolome and proteome between wet and dry nights in children with monosymptomatic nocturnal enuresis and nocturnal polyuria.

BACKGROUND: Nocturnal enuresis (NE) is a common disease with multiple pathogenic mechanisms. This study aimed to compare levels of metabolites and proteins between wet and dry nights in urine samples from children with monosymptomatic NE (MNE). METHODS: Ten boys with MNE and nocturnal polyuria (age: 7.6 ± 1.3 years) collected their total nighttime urine production during a wet and a dry night. Untargeted metabolomics and proteomics were performed on the urine samples by liquid chromatography coupled with high-mass accuracy tandem mass spectrometry (LC-MS/MS). RESULTS: On wet nights, we found reduced urine osmolality (P = 0.025) and increased excretion of urinary potassium and sodium by a factor of, respectively, 2.1 (P = 0.038) and 1.9 (P = 0.19) compared with dry nights. LC-MS identified 59 metabolites and 84 proteins with significantly different levels between wet and dry nights (fold change (FC) < 0.67 or > 1.5, P < 0.05). Some compounds were validated by different methodologies. During wet nights, levels of compounds related to oxidative stress and blood pressure, including adrenalin, were increased. We found reduced levels of aquaporin-2 on wet nights. The FCs in the 59 metabolites were positively correlated to the FCs in the same metabolites identified in urine samples obtained during the evening preceding wet and dry nights. CONCLUSIONS: Oxidative stress, which in the literature has been associated with nocturia and disturbances in sleep, might be increased during wet nights in children with MNE. We further found evidence of increased sympathetic activity. The mechanisms related to having wet nights in children with MNE seem complex, and both free water and solute handling appear to be important. A higher resolution version of the Graphical abstract is available as Supplementary information.

Transcutaneous electrical nerve stimulation as add-on therapy in children receiving anticholinergics and/or mirabegron for refractory daytime urinary incontinence: A retrospective cohort study.

AIMS: To investigate if children with daytime urinary incontinence (DUI) and overactive bladder (OAB) refractory to standard urotherapy and medicinal treatment, would experience improvement in symptoms after add-on treatment with transcutaneous electrical nerve stimulation (TENS). METHODS: Children were retrospectively enrolled from tertiary referral centers at Aarhus and Aalborg University Hospitals. All data were retrieved from the patients' journals. All children were prescribed TENS as an add-on treatment to the highest-tolerable dose of medicinal treatment in a standardized regime of 2 h a day for around 3 months. Primary endpoints were the number of wet days per week (WDPW) and incontinence episodes per day. Effect of treatment was defined as greater or equal to 50% reduction in the frequency of DUI episodes. Secondary endpoints were to establish predictive factors for the effect of treatment using logistic regression. RESULTS: Seventy-six children diagnosed with DUI and OAB refractory to treatment with standard urotherapy and pharmacological treatment, at the age of 5-16 years were included from February 2017 to February 2020. A reduction in WDPW (from 6.31 [5.86-6.61] to 4.27 [3.45-4.90], p < 0.05) and incontinence episodes per day (from 2.45 [1.98-2.91] to 1.43 [1.07-1.80], p < 0.05) was observed. Twelve patients became completely dry. At 6 months follow-up, seven of the 12 complete responders had relapsed while five remained dry. A history of constipation before TENS was a predictor of poor treatment response (p = 0.016). CONCLUSIONS: TENS as add-on to anticholinergic treatment seems effective in a number of children with treatment-refractory DUI.

The efficacy of physiotherapeutic intervention with biofeedback assisted pelvic floor muscle training in children with dysfunctional voiding.

INTRODUCTION: Dysfunctional voiding (DV) in children is a common issue, which can be found in up to 30% of children with wetting problems. Biofeedback assisted pelvic floor muscle training (PFMT) is an established nonpharmacological method to treat DV. The aim of the present study was to evaluate the efficacy of physiotherapeutic intervention with biofeedback assisted PFMT in children with DV. STUDY DESIGN: Children referred with DV, unresponsive to standard urotherapy were included in this study. All children underwent biofeedback assisted PFMT sessions with a physiotherapist. Uroflowmetries and measurements of post-void residual (PVR) urine were performed before and after the treatment, and the following parameters were registered; daytime incontinence (DI), nocturnal enuresis (NE), constipation, faecal incontinence (FI), and recurrent urinary tract infections (UTI). Other concomitant treatments were noted. The primary outcomes were the resolution of DV evaluated by uroflow curve configuration and PVR. Secondary outcomes were the resolution of DI, NE and the reduction of recurrent UTIs. RESULTS: Forty-six children (mean age 9.6 ± 2.4 years, 38 girls) were included in the analysis. The median period of treatment was 9.0 ± 8.5 months (2-9 visits). Twenty-seven (59%) children responded to treatment according to one or both primary outcomes; uroflow configuration (50%) and PVR (28%). DI resolved in 12 (26%) children and 27 of the 32 children, who prior to the treatment had recurrent UTIs experienced no UTIs during the follow up period. The use of anticholinergics was a significant negative predictor for response to treatment. We found that almost half of the responders (48%) reached effect prior to the fourth visit. DISCUSSION: Biofeedback assisted PFMT can improve the symptoms in children with DV. When comparing to existing literature we find a less pronounced effect of the intervention. A possible explanation may be that the children enrolled in this study were recruited from a tertiary referral centre and were all refractory to standard urotherapy. Moreover, the difference in patient characteristics and treatment protocols between different studies make direct comparisons of efficacy difficult. CONCLUSION: Physiotherapeutic intervention with biofeedback assisted PFMT seems to lead to better uroflow patterns in approximately 60% of cases in DV improving the uroflow curves and PVR, however improvement in uroflowmetry patterns is not necessarily reflected in the resolution of incontinence or UT symptoms. The use of anticholinergics seems to be a negative predictor for response to treatment.

Transcutaneous Electrical Nerve Stimulation in Children with Monosymptomatic Nocturnal Enuresis: A Randomized, Double-Blind, Placebo Controlled Study.

PURPOSE: In a third of all children with monosymptomatic nocturnal enuresis their condition is refractory to first line treatments. Transcutaneous electrical nerve stimulation has been documented to be efficacious in children with daytime incontinence. We investigated the effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. MATERIALS AND METHODS: Children with monosymptomatic nocturnal enuresis (3 or more wet nights per week) and no nocturnal polyuria were randomized to treatment with active or sham transcutaneous electrical nerve stimulation involving 1-hour sessions twice daily for 10 weeks in a double-blind design. RESULTS: Of the 52 children with monosymptomatic nocturnal enuresis included in the study 47 completed treatment (mean age 9.5 ± 2.1 years, 38 males). None of the children experienced a full response with complete remission of enuresis. Treatment with transcutaneous electrical nerve stimulation did not lead to significant changes in number of wet nights, nocturnal urine production on wet or dry nights, maximum voided volume with and without first morning voided volume, or voiding frequency when comparing parameters before and after treatment. CONCLUSIONS: The present study demonstrates no anti-enuretic effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. Nocturnal urine production and bladder capacity remained unchanged during and after treatment with transcutaneous electrical nerve stimulation.

Outcome of a standardized approach to childhood urinary symptoms-long-term follow-up of 720 patients.

AIMS: To investigate the relevance of enuresis subtyping for selection of treatment modality and for long-term outcome in a large consecutive patient cohort. MATERIALS AND METHODS: We included all patients referred for urinary incontinence during a 5-year period but excluding recurrent urinary tract infections (UTI). Type and severity of incontinence, prior history, results of examinations performed, number of visits, and effect of all treatments provided, were included in a clinical database. RESULTS: Seven hundred twenty children aged 4-16 years (mean 8.5 ± 2.2 years, 239 girls) were included in the analysis (42% with monosymptomatic (MNE), 55% with non-MNE, and 3% with isolated daytime incontinence). Initial evaluation revealed only few underlying causes (one neurological and eight anatomical). Investigations showed significant differences between MNE and non-MNE patients as both maximal voided volume and nocturnal urine volume was lower in non-MNE patients (P < 0.001). Follow-up for average 1,587 days (3.4 years) was performed in 660 (92%) patients. A higher number of visits and a longer treatment period were needed for non-MNE patients (on average 4.7 ± 2.8 visits) than MNE patients (3.1 ± 1.6 visits, P < 0.001). The most common treatment regimen that resulted in dryness in both MNE (40%) and non-MNE (36%) was the alarm system. Interestingly, of the 539 patients who initially were referred due to desmopressin resistance 177 (33%) of these were dry on desmopressin monotherapy. CONCLUSIONS: The study indicated that MNE and non-MNE are two distinct disease entities with different optimal treatments and showed that the latter patients are more difficult and time-consuming to manage.

Diverse vasopressin V2 receptor functionality underlying partial congenital nephrogenic diabetes insipidus.

X-linked congenital nephrogenic diabetes insipidus (CNDI) is characterized by a defective renal response to the antidiuretic hormone (AVP) due to variations in the arginine vasopressin receptor 2 (AVPR2) gene. In a unique group of patients, the renal insensitivity to the effects of AVP is incomplete resulting in a partial phenotype. To investigate the molecular defects, two previously published variations in the AVPR2 gene, known to cause a partial CNDI phenotype, were expressed in transiently transfected human embryonic kidney cells. One variation (p.Arg104Cys) is located in the first extracellular loop and the other variation (p.Ser329Arg) is located in the intracellular COOH terminal of the receptor protein. Western blotting showed almost equal amounts of WT-V2R and Arg104Cys-V2R protein at steady state, whereas the level of Ser329Arg-V2R protein was lower. Confocal microscopy established that WT-V2R and Arg104Cys-V2R are localized on the cellular surface while the Ser329Arg-V2R primarily accumulates within the endoplasmic reticulum resulting in reduced surface expression. Ligand binding analysis demonstrated that the B(max) for cells expressing Arg104Cys-V2R and Ser329Arg-V2R were 14.8- and 2.5-fold lower than B(max) for WT-V2R, respectively. AVP affinity (1/K(d)) for WT-V2R and the Ser329Arg-V2R was similar while 1/K(d) for Arg104Cys-V2R was increased. cAMP assay revealed that cells expressing p.Arg104Cys-V2R or p.Ser329Arg-V2R produced 1.7- and 6.8-fold lower amounts of cAMP compared with WT-V2R, respectively. In conclusion, ligand binding and signal transduction capability are dependent on localization of the amino acid variation. Striking divergences at the level of receptor functionality may thus underlie similar clinical phenotypes in CNDI.

Transcutaneous electrical nerve stimulation for refractory daytime urinary urge incontinence.

PURPOSE: We studied the effect of transcutaneous electrical nerve stimulation in children with overactive bladder and treatment refractory daytime urinary incontinence. MATERIALS AND METHODS: We recruited 27 children 5 to 14 years old with daytime urge incontinence refractory to timer assisted standard urotherapy and anticholinergics who had normal urinalysis, and unremarkable urinary tract ultrasound and physical examination. Study exclusion criteria were bladder underactivity, lower urinary tract obstruction, ongoing defecation disorders, lower urinary tract surgery and previous transcutaneous electrical nerve stimulation. After a 2-week run-in of standard urotherapy the children underwent natural fill ambulatory urodynamics to confirm detrusor overactivity. Subsequently they were randomly allocated to 4 weeks of 2 hours of daily active or placebo S2-S3 transcutaneous electrical nerve stimulation. The severity of incontinence and urgency, and 48-hour bladder diaries were recorded before randomization and during intervention week 4. Children withdrew from anticholinergics throughout the study period. RESULTS: Two children were excluded from randomization due to urodynamic signs of lower urinary tract obstruction. After 4 weeks of intervention 8 children (61%) in the active group showed a significant decrease in incontinence severity but this occurred in only 2 (17%) in the sham treated group (p <0.05). The active group had a significantly greater decrease in daily incontinence episodes compared to the sham treated group (p <0.01). Transcutaneous electrical nerve stimulation did not alter maximal and average voided volumes. CONCLUSIONS: Sacral transcutaneous electrical nerve stimulation seems superior to placebo for refractory daytime incontinence in children with overactive bladder. This effect does not seem to be a consequence of improved bladder reservoir function.

The effect of desmopressin on renal water and solute handling in desmopressin resistant monosymptomatic nocturnal enuresis.

PURPOSE: We sought to evaluate the effect of desmopressin on renal water and solute handling in children with monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria compared to healthy controls. MATERIALS AND METHODS: A total of 12 patients with enuresis and nocturnal polyuria, normal bladder reservoir function and no response to desmopressin, and 10 age matched controls were enrolled in the study. Children were admitted to the hospital for a 48-hour protocol comprising urine collections and blood sampling. Sodium and water intake was standardized. During the second night children received 40 mug intranasal desmopressin. Parameters characterizing the renal water and solute handling were measured and compared between baseline nights and nights with desmopressin. RESULTS: Desmopressin markedly reduced nocturnal urine output in patients with enuresis, minimizing sodium, urea and overall solute excretion, despite the fact that these children were unresponsive to desmopressin at home. This effect on renal sodium handling was not mediated by atrial natriuretic peptide, angiotensin II, aldosterone or renin. Desmopressin did not influence urinary prostaglandin E(2) excretion. The antinatriuretic effect was seen only in patients with enuresis, and it was directly correlated with the reduction in urine output. CONCLUSIONS: Children with nocturnal enuresis and nocturnal polyuria who do not exhibit adequate response to desmopressin at home seem to respond well to the agent at the clinic. The effect of desmopressin in children with enuresis seems largely dependent on reductions in the amount of sodium excreted. Sodium regulating hormones remained unaffected by desmopressin, indicating a possible direct effect of the agent on renal sodium handling.