SODIUM FRACTION EXCRETION RATE IN NOCTURNAL ENURESIS CORRELATES WITH NOCTURNAL POLYURIA AND OSMOLALITY

Transition in enuresis patients: Identifying the gaps and opportunities for the future

BACKGROUND

Nocturnal enuresis is generally considered a children's condition, yet it may persist 1%-2% in adolescence and early adulthood. Refractory patients often demand follow-up by multidisciplinary teams, which is only restricted to some of the expert tertiary centers. However, there are no standardized transition programs/guidelines when follow-up must be passed from pediatric to adult healthcare providers.

AIM, MATERIALS & METHODS

To investigate this issue, we conducted a literature search on enuresis transition, which resulted in no articles. We, therefore, proceeded in a rescue search strategy: we explored papers on transition programs of conditions that may be related and/or complicated by enuresis, nocturia, or other urinary symptoms (chronic diseases, CKD, bladder dysfunction, kidney transplant, neurogenic bladder).

RESULTS

These programs emphasize the need for a multidisciplinary approach, a transition coordinator, and the importance of patient and parent participation, practices that could be adopted in enuresis. The lack of continuity in enuresis follow-up was highlighted when we investigated who was conducting research and publishing on enuresis and nocturia. Pediatric disciplines (50%) are mostly involved in children's studies, and urologists in the adult ones (37%).

DISCUSSION

We propose a stepwise approach for the transition of children with enuresis from pediatric to adult care, depending on the clinical subtype: from refractory patients who demand more complex, multidisciplinary care and would benefit from a transition coordinator up to children/young adults cured of enuresis but who persist in having or present lower urinary tract symptoms (LUTS)/nocturia later on. In any case, the transition process should be initiated early at the age of 12-14 years, with adequate information to the patient and parents regarding relapses or LUTS/nocturia occurrence and of the future treating general practitioner on the enuresis characteristics and comorbidities of the patient.

Management of treatment-resistant nocturnal enuresis

Nocturnal enuresis is defined as intermittent urinary incontinence during sleep in children 5 years of age and older, occurring at least once a month for at least 3 months. In Japan, pediatricians who do not specialize in nocturnal enuresis have become more proactive in treating the condition since 2016, when the guidelines for treating it were revised for the first time in 12 years. For monosymptomatic nocturnal enuresis, the first step is lifestyle guidance, with a focus on the restriction of fluid intake at night; however, if lifestyle guidance does not decrease the frequency of nocturnal enuresis, aggressive treatment should be added. The first choice of aggressive treatment is oral desmopressin, an antidiuretic hormone preparation, or alarm therapy. However, there remain patients whose wet nights do not decrease with oral desmopressin or alarm therapy. In such cases, it is necessary to reconfirm the method of desmopressin administration and check for factors that may decrease the efficacy of desmopressin. If alarm therapy does not increase the number of dry nights, it is possible that the patient is fundamentally unsuitable for alarm therapy. If dry nights do not increase with oral desmopressin or alarm therapy, the next treatment strategy should be considered immediately to keep the patient motivated for treatment.

Nocturnal enuresis: A topic review and institution experience

The objective is to provide a review of nocturnal enuresis (NE), including its epidemiology, etiology, pathophysiology, evaluation, and current management. We also set to provide further insight on the treatment of this condition from the experience derived from patients cared for at our tertiary-care institution. NE affects approximately 15% of all children at 5-year-old, affecting boys more frequently than girls. At our large university tertiary pediatric urology center, NE and incontinence, in general, is one the most common chief complaints prompting urologic care. In this review, we examine the condition in detail, highlighting specific goals of the initial evaluation and treatment. We contrast the commonly implemented treatment recommendations, available from the literature with strategies we have found valuable from our extensive experience in treating patients with this disorder. Using current urologic reference textbooks, book chapters, Medline, journal articles and reviews describing the many aspects of NE were reviewed in order to describe NE and the current practices at our institution. Although, this is not a systematic literature review, it includes relevant available research, institutional experience and urological expert opinion and current practices at a tertiary state health facility. The treatment of NE remains a challenge for many pediatricians and pediatric urologists. This likely stems from the multiple possible etiologies of the disorder. We have established a treatment algorithm at our institution, which we have found successful in the majority of our patients. This consists of starting patients on urotherapy, then offering both the enuresis alarm device and medication therapy as first line treatments, and finally adding anticholingerics for combination therapy. Our hope is with further research the treatment of NE will continue to improve.

The biofeedback treatment for non-monosymptomatic enuresis nocturna

AIMS

Enuresis is a child older than 5 years wetting in discrete portions during sleep. It has two subgroups: monosymptomatic enuresis nocturna (MSEN) and non-monosymptomatic enuresis nocturna (NMSEN). In this research, we specifically aimed to examine the effect of biofeedback in NMSEN.

METHODS

We retrospectively analyzed the hospital records of 182 children with NMSEN who were refractory to urotherapy modifications and directed to biofeedback therapies between 2005 and 2010. Enuresis before and after biofeedback therapies was evaluated. One or less enuretic night in a month was defined as success.

RESULTS

There were 118 (64%) girls and 64 (35%) boys. With biofeedback therapy, 117 of 182 patients recovered with a success rate of 64% (P < 0.001), but 65 patients still had enuresis. Seventy-two out of 118 girls recovered with a success rate of 61% (P < 0.001), whereas 45 out of 64 boys recovered with a success rate of 70% (P = 0.001). The NMSEN complaints of daytime incontinence, dysuria, urgency, holding maneuvers, and urgency incontinence disappeared significantly concomitant to the enuresis component, as well (P < 0.05).

CONCLUSIONS

Biofeedback therapy is an effective treatment option for the enuresis component of NMSEN with a 64% success rate.

Urinary calcium excretion in children with monosymptomatic enuresis

Background

Among many factors predisposing to monosymptomatic enuresis (MNE) disturbances in urinary electrolites excretion play an important role. Because of many controversies in this field there is a need to debate the role of hypercalciuria in MNE. The aim of our study was to determine the urinary calcium in children with MNE.

Methods

The investigation was conducted on 204 children (83 MNE children and 121 reference group). Urinary calcium excretion (in 24-h collection and per kg of body mass), Ca/creatinine ratio, Ca²⁺ in urine sample and in 24-h collection of urine were estimated.

Results

Hypercalciuria in MNE group was diagnosed in 18/83 (21.69 %) patients. We found statistically significant differences between children with MNE in Ca²⁺ in urine sample and 24-h collection and Ca/creat. ratio. Median urinary calcium excretion (mg/kg/24-h and mmol/24-h) was significantly higher in hypercalciuric enuretic patients. The urinary total calcium (mmol/24-h), urinary bound calcium and urinary calcium concentration (mmol/L) demonstrated a significant positive correlation with height, weight and age in reference group but not in MNE group.

Conclusion

Urinary calcium excretion was significantly disturbed and further studies are needed to assess the role of hypercalciuria in the pathogenesis of MNE.

Non-dipping phenomenon in children with monosymptomatic nocturnal enuresis

PURPOSE

Monosymptomatic nocturnal enuresis is a common disorder seen in childhood, and many factors play a role in its etiopathology to varying degrees. The aim of our study was to investigate the possible association between nocturnal enuresis and 24-h blood pressure profiles of enuretic children.

METHODS

A total of 45 children ranging in age from 6 to 15 years with monosymptomatic nocturnal enuresis and 22 age-matched healthy controls were enrolled in our study. The blood pressure measurement was made at 30-min intervals during a 24-h period via an ambulatory blood pressure measurement device. Both groups underwent medical tests that included a complete blood count, blood biochemistry profile, urinalysis and blood renin-aldosterone levels, and all study subjects received an abdominal ultrasound.

RESULTS

Statistically significant high nocturnal blood pressure levels were observed in our patients with monosymptomatic nocturnal enuresis compared with the control group (p < 0.05). The mean values of the day-to-night difference (dipping) in the systolic and diastolic blood pressure of the patients were significantly lower than those of control group (p < 0.05).

CONCLUSION

Nocturnal enuresis should not only be accepted as a urinary system disorder. Possible systemic causative factors have to be examined, especially in patients that are resistant to first-line therapy. Based on the results of our study, we deduce that one of the factors that plays a role in the pathogenesis of enuresis nocturna is a non-dipping blood pressure profile (the "non-dipping" phenomenon).

Is there any correlation between hypercalciuria and nocturnal enuresis?

Nocturnal enuresis is a common problem among children. Hypercalciuria has been proposed as an important etiology of bedwetting. We investigated the incidence of hypercalciuria among children with nocturnal enuresis and age- and sex-matched healthy controls. In this case–control study 118 children with nocturnal enuresis and 100 age-, sex-, and educational district-matched healthy controls were recruited. Urine samples were obtained from each subject twice: immediately after awakening and 2 hours later at school. Urinary calcium and creatinine levels were measured and the subjects with a urinary calcium/creatinine ratio more than 0.2 were considered as hypercalciuric. Serum Ca, P, Na, K, and PTH levels were measured for all hypercalciuric subjects. The mean urine calcium to creatinine ratio in the second urine sample was 0.070±0.06 mg/mg and 0.050±0.046, respectively in the case and control groups (P=0.008). There were 12/118 and 3/100 hypercalciuric subjects in the case and control groups respectively (P=0.032). The serum Ca, P, Na, K, and PTH levels were in normal range in all hypercalciuric subjects. In our study there was a significant difference in the frequency of hypercalciuria among children with nocturnal enuresis and healthy controls, so we can suggest adding the measurement of urine electrolytes especially the calcium level in patients with nocturnal enuresis.

Sleep deprivation induces excess diuresis and natriuresis in healthy children

Urine production is reduced at night, allowing undisturbed sleep. This study was undertaken to show the effect of sleep deprivation (SD) on urine production in healthy children. Special focus was on gender and children at an age where enuresis is still prominent. Twenty healthy children (10 girls) underwent two 24-h studies, randomly assigned to either sleep or SD on the first study night. Diet and fluid intake were standardized. Blood samples were drawn every 4 h during daytime and every 2 h at night. Urine was fractionally collected. Blood pressure and heart rate were noninvasively monitored. Blood was analyzed for plasma antidiuretic hormone (AVP), atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin. Urine was analyzed for aquaporin-2 and PGE2. Successful SD was achieved in all participants with a minimum of 4 h 50 min, and full-night SD was obtained in 50% of the participants. During SD, both boys and girls produced markedly larger amounts of urine than during normal sleep (477 ± 145 vs. 291 ± 86 ml, P < 0.01). SD increased urinary excretion of sodium (0.17 ± 0.05 vs. 0.10 ± 0.03 mmol·kg−1·h−1) whereas solute-free water reabsorption remained unchanged. SD induced a significant fall in nighttime plasma AVP ( P < 0.01), renin ( P < 0.05), angiotensin II ( P < 0.001), and aldosterone ( P < 0.05) whereas plasma ANP levels remained uninfluenced ( P = 0.807). Nighttime blood pressure and heart rate were significantly higher during SD (mean arterial pressure: 78.5 ± 8.0 vs. 74.7 ± 8.7 mmHg, P < 0.001). SD leads to natriuresis and excess diuresis in healthy children. The underlying mechanism could be a reduced nighttime dip in blood pressure and a decrease in renin-angiotensin-aldosterone system levels during sleep deprivation.

Randomized comparison of long-term desmopressin and alarm treatment for bedwetting

OBJECTIVE

To compare the efficacy of long-term primary nocturnal enuresis (PNE) treatment using desmopressin versus enuresis alarm.

MATERIALS AND METHODS

A 6-month randomized trial was performed with patients from 29 enuresis clinics: 251 patients ≥ 5 years in age with severe PNE (mean 5.5-5.6 wet nights/week) were randomized to desmopressin (0.2-0.4 mg daily) or alarm. Efficacy was assessed by percentage reduction in mean number of wet nights/week; patients achieving dryness, mean initial duration of sleep and compliance were evaluated. Efficacy analyses were performed using the intent-to-treat population (all patients) and excluding patients who withdrew; 12-month follow-up data were collected.

RESULTS

Data could not be evaluated for the 32% of alarm patients and 7% of desmopressin patients who withdrew early. In intent-to-treat analyses, a similar proportion of patients across groups showed a ≥ 50% reduction in wet nights/week (desmopressin: 37.5%, alarm: 32.2%) and achieved dryness (desmopressin: 32%, alarm: 37%). Compliance was higher with desmopressin: 95-98% of patients took >75% of tablets; 50-78% used alarm >75% of nights. Initial sleep duration was 1.02 h longer at the end of treatment with desmopressin (95% CI: 0.045, 1.99).

CONCLUSION

Desmopressin and alarm demonstrated comparable efficacy in the treatment of PNE. Withdrawal from the alarm group was high, indicating the importance of considering family motivation before selecting treatment, for optimal outcome.

Excess diuresis and natriuresis during acute sleep deprivation in healthy adults

The transition from wakefulness to sleep is associated with a pronounced decline in diuresis, a necessary physiological process that allows uninterrupted sleep. The aim of this study was to assess the effect of acute sleep deprivation (SD) on urine output and renal water, sodium, and solute handling in healthy young volunteers. Twenty young adults (10 male) were recruited for two 24-h studies under standardized dietary conditions. During one of the two admissions, subjects were deprived of sleep. Urine output, electrolyte excretions, and osmolar excretions were calculated. Activated renin, angiotensin II, aldosterone, arginine vasopressin, and atrial natriuretic peptide were measured in plasma, whereas prostaglandin E2 and melatonin were measured in urine. SD markedly increased the diuresis and led to excess renal sodium excretion. The effect was more pronounced in men who shared significantly higher diuresis levels during SD compared with women. Renal water handling and arginine vasopressin levels remained unaltered during SD, but the circadian rhythm of the hormones of the renin-angiotensin-aldosterone system was significantly affected. Urinary melatonin and prostaglandin E2 excretion levels were comparable between SD and baseline night. Hemodynamic changes were characterized by the attenuation of nocturnal blood pressure dipping and an increase in creatinine clearance. Acute deprivation of sleep induces natriuresis and osmotic diuresis, leading to excess nocturnal urine production, especially in men. Hemodynamic changes during SD may, through renal and hormonal processes, be responsible for these observations. Sleep architecture disturbances should be considered in clinical settings with nocturnal polyuria such as enuresis in children and nocturia in adults.

Desmopressin for the treatment of primary nocturnal enuresis

Primary nocturnal enuresis (PNE) affects a large proportion of children aged 5 years and over, and can persist into adolescence if left untreated. To patients and families, the condition is extremely distressing and embarrassing, as well as inconvenient owing to the increased washing of bedclothes required, and the difficulties surrounding socializing, such as planning sleepovers or holidays. PNE is caused by a mismatch between the capacity of the bladder to store urine and the volume of urine produced at night, which is frequently excessive in children with PNE. Excessive urine production at night can be caused by an impairment of the circadian rhythm of antidiuretic hormone secretion. Treatment for PNE is primarily by means of behavioral conditioning or pharmacological therapy. Desmopressin is a synthetic analogue of naturally occurring antidiuretic hormone, and is the only pharmacological therapy with a Grade A, level 1 recommendation from the International Consultation on Incontinence as a first-line treatment for PNE. Desmopressin is a well-established and generally well-tolerated treatment for nocturnal enuresis. The only potentially serious adverse effect of desmopressin is hyponatremia, which is rare and has predominantly been observed with the intranasal form of the drug – this formulation has now been withdrawn for the PNE indication in most countries. This review will explore the pharmacology, clinical efficacy and tolerability of desmopressin and its oral formulations in PNE, including the tablet and the more recent oral lyophilisate.

Increased excretion of glycosaminoglycans in children with urinary incontinence compared to those with monosymptomatic nocturnal enuresis

OBJECTIVE

To analyse the urinary excretion of glycosaminoglycans (GAGs) in patients with either urinary incontinence or nocturnal enuresis.

MATERIAL AND METHODS

The study population comprised 65 patients with either nocturnal enuresis (n=34) or urinary incontinence (n=31) and 67 controls. Excretion of urinary GAGs was assessed using the sodium tetraborate-carbazole method.

RESULTS

GAG excretion in patients with urinary incontinence was significantly higher than that in controls (p<0.000129) and in children with nocturnal enuresis (p<0.016). There were no age or sex differences in GAG excretion in the three groups studied.

CONCLUSION

Increased GAG excretion in patients with urinary incontinence suggests an association with urothelial/detrusor pathology.

Nocturnal polyuria is related to 24-hour diuresis and osmotic excretion in an enuresis population referred to a tertiary center

PURPOSE

Primary nocturnal enuresis is a heterogeneous disorder, causing a mismatch between overnight diuresis volume and functional bladder capacity. Despite increasing insights in pathogenesis, lack of efficacy of the available treatments is a major problem. We evaluated characteristics of bladder volume and diuresis rate in patients with nocturnal enuresis referred to a tertiary enuresis center.

MATERIALS AND METHODS

Noninvasive screening including maximal voided volume, 24-hour circadian rhythm of diuresis and osmotic excretion from 1,000 consecutive patients.

RESULTS

Of the patients referred as having monosymptomatic nocturnal enuresis 32% were subsequently classified as having nonmonosymptomatic nocturnal enuresis. Differences in bladder volume and nocturnal diuresis characteristics between the monosymptomatic nocturnal enuresis and nonmonosymptomatic nocturnal enuresis groups were minimal.

CONCLUSIONS

The most common observation is a nocturnal diuresis volume greater than maximal voided volume, which in both groups can be caused by nocturnal polyuria or small bladder volume for patient age. The most striking observation is that the positive correlation between nocturnal diuresis volume rate and nocturnal osmotic excretion and 24-hour fluid intake is significantly higher than with the inversed urinary osmolality overnight, which is not only unexpected based on the theory of the primary suppression of vasopressin levels overnight, but also points to a more important role for nutritional and fluid intake than accepted, if not in the primary pathogenesis, then at least in therapy resistance.

Nocturia and Circadian Blood Pressure Profile in Healthy Elderly Male Volunteers

PURPOSE

Nocturia is attributed to nocturnal polyuria and/or decreased functional bladder capacity. In this study we elucidated the mechanisms behind circadian fluid regulation and the occurrence of nocturia in healthy elderly males, specifically to determine the role of urine output and regulating hormones, blood pressure, and average voided volumes.

MATERIALS AND METHODS

A total of 18 males 55 to 73 years old (mean age 61.1) were included in the study. Voiding habits were assessed by completion of a 7-day frequency volume chart recording all fluid intake and voiding. The subjects subsequently underwent inpatient circadian studies measuring the diurnal rhythm of blood pressure, vasopressin, atrial natriuretic peptide, angiotensin II, aldosterone and urine volume.

RESULTS

Of the nightly home recordings 25% showed nocturia, characterized by a higher 24-hour and nighttime urine volume. During the inpatient studies 12 of the 18 participants experienced a nocturnal void. Nocturia nights were characterized by significantly decreased day-to-night ratios in urine output and a higher nighttime mean arterial blood pressure. A circadian variation in plasma arginine vasopressin was seen only in the group without nocturia. The other hormones revealed a circadian rhythm similar in the 2 groups.

CONCLUSIONS

In healthy males with occasional nocturia, the occurrence of nocturia seems to be associated with a blunting of the circadian rhythm of diuresis and increased arterial blood pressures during the night. These findings may implicate a role for a baroregulatory related mechanism in nocturia.