Nocturia in Menopausal Women: The Link Between Two Common Problems of the Middle Age

INTRODUCTION AND HYPOTHESIS

The aim of this review is to discuss the link between menopause and nocturia and to give an overview of the increasing prevalence, risk factors, causative factors, treatment needs and options for nocturia in peri-menopausal women.

METHODS

This opinion article is a narrative review based on the expertise and consensus of a variety of key opinion leaders, in combination with an extensive literature review. This literature search included a thorough analysis of potential publications on both the PubMed Database and the Web of Science and was conducted between November 2022 and December 2022. The following key words were used "nocturia" and "menopause" or "nocturnal frequency and menopause." Moreover, key words including "incidence," "prevalence," "insomnia," "estrogen therapy," "metabolic syndrome," and "hot flushes" were used in combination with the aforementioned key words. Last, the reference lists of articles obtained were screened for other relevant literature.

RESULTS

The perimenopause can be a trigger for inducing nocturia. Typically, obesity, body mass index (BMI), and waist circumference are risk factors for developing peri-menopausal nocturia. Presumably the development of peri-menopausal nocturia is multifactorial, with interplay among bladder, sleep, and kidney problems due to estrogen depletion after the menopause. First, impaired stimulation of estrogen receptors in the urogenital region leads to vaginal atrophy and reduced bladder capacity. Moreover, menopause is associated with an increased incidence of overactive bladder syndrome. Second, estrogen deficiency can induce salt and water diuresis through blunted circadian rhythms for the secretion of antidiuretic hormone and the activation of the renin-angiotensin-aldosterone system. Additionally, an increased incidence of sleep disorders, including vasomotor symptoms and obstructive sleep apnea signs, is observed. Oral dryness and a consequent higher fluid intake are common peri-menopausal symptoms. Higher insulin resistance and a higher risk of cardiovascular diseases may provoke nocturia. Given the impact of nocturia on general health and quality of life, bothersome nocturia should be treated. Initially, behavioral therapy should be advised. If these modifications are inadequate, specific treatment should be proposed. Systemic hormone replacement is found to have a beneficial effect on nocturia, without influencing sodium and water clearance in patients with nocturnal polyuria. It is presumed that the improvement in nocturia from hormonal treatment is due to an improvement in sleep disorders.

Is the insomnia phenotype the common denominator in LUTS during transition periods? An expert NOPIA research group review

AIMS

As people age, sleep stages and characteristics transition over time, but sleep deficits can profoundly impact health and cognitive functioning. Chronic sleep deprivation is linked to impaired attention and productivity, weakened immunity, increased risk of cardiovascular disease, obesity, and mental health disorders. Insomnia, obstructive sleep apnea syndrome, hormonal changes, nocturia, neurological disorders, and life events interfere with sleep patterns and some are linked to lower urinary tract symptoms (LUTS). This NOPIA symposium on Lifelong LUTS aimed to analyze the literature on associations between sleep and LUTS, generate ideas for future research, and explore whether there is support for the concept of lifelong LUTS in relation to changes in sleep throughout the lifespan.

METHODS

An international panel of experts took part in an online meeting addressing the role of lifelong LUTS in relationship to sleep and the brain organized by the NOPIA research group. The manuscript summarizes existing literature, hypotheses, future research ideas, and clinical recommendations.

RESULTS

Insomnia, sleep fragmentation, hyperarousal, and sensory processing disorders emerged as potential factors in the relationship between sleep and LUTS. Insomnia is often a persistent factor and may have been the initial symptom; however, it is often unrecognized and/or unaddressed in healthcare settings. By recognizing insomnia as a primary driver of various health issues, including nocturia, transitional care aims to address root causes and underlying problems earlier to initiate appropriate treatment.

CONCLUSIONS

A multidisciplinary approach with collaboration between healthcare professionals from various disciplines, such as urology, sleep medicine, gynecology, pediatrics, and geriatrics, is needed and should include validated measurements such as the insomnia severity index and sleep and voiding diaries. Ensuring ongoing follow-up and monitoring through transitional care is crucial for individuals with persistent sleep problems and LUTS, allowing issues that arise or fluctuate over the lifespan to be addressed.

Different approaches for bladder neck dissection during robot-assisted radical prostatectomy: the Aalst technique

INTRODUCTION

Bladder neck dissection is one of the most delicate surgical steps of robotic-assisted radical prostatectomy (RARP) [1, 2], and it may affect surgical margins rate and functional outcomes [3, 4]. Given the relationship between outcomes and surgical experience [5-7], it is crucial to implement a step-by-step approach for each surgical step of the procedure, especially in the most challenging part of the intervention. In this video compilation, we described the techniques for bladder neck dissection utilized at OLV Hospital (Aalst, Belgium).

SURGICAL TECHNIQUE

We illustrated five different techniques for bladder neck dissection during RARP. The anterior technique tackles the bladder neck from above until the urethral catheter is visualized, and then the dissection is completed posteriorly. The lateral and postero-lateral approaches involve the identification of a weakness point at the prostate-vesical junction and aim to develop the posterior plane - virtually until the seminal vesicles - prior to the opening of the urethra anteriorly. Finally, we described our techniques for bladder neck dissection in more challenging cases such as in patients with bulky middle lobes and prior surgery for benign prostatic hyperplasia. All approaches follow anatomic landmarks to minimize positive surgical margins and aim to preserve the bladder neck in order to promote optimal functional recovery. All procedures were performed with DaVinci robotic platforms using a 3-instruments configuration (scissors, fenestrated bipolar, and needle driver). As standard protocol at our Institution, urinary catheter was removed on postoperative day two [8].

CONCLUSIONS

Five different approaches for bladder neck dissection during RARP were described in this video compilation. We believe that the technical details provided here might be of help for clinicians who are starting their practice with this surgical intervention.

Holmium Laser Enucleation of the Prostate versus Robotic Assisted Simple Prostatectomy for lower urinary tract symptoms in patients with extremely large prostates ≧200 ml: A comparative analysis

Introduction and objectives Robot-Assisted Simple Prostatectomy (RASP) and Holmium Laser Enucleation of the prostate (HoLEP) are both well-established, minimally-invasive surgical treatment options for lower urinary tract symptoms caused by benign prostatic enlargement. We have reported the first comparative analysis of both techniques in patients with prostates of 200ml. Materials & methods Between 2009 and 2020 a total of 53 patients with a prostate volume of 200ml were surgically treated at OLV Hospital Aalst (Belgium): 31 underwent RASP and 22 underwent HoLEP. Preoperative and postoperative assessments included uroflowmetry with maximum urinary flow rate (Qmax) and post-void residual volume (PVR), as well as the International Prostate Symptom Score (IPSS) and quality of life (IPSS-QoL). The complication rates were evaluated according to the Clavien-Dindo Classification. Results Patients treated with RASP had significantly larger prostate volumes compared to HoLEP (median 226 vs. 204.5 ml, p=0.004). After a median follow-up of 14 months, both groups showed a significant improvement in the maximum flow rate (+10.60 vs. +10.70 ml/s, p=0.724) and a reduction of the IPSS score (-12.50 vs. -9, p=0.246) as well as improvement of the QoL (-3 vs. -3, p=0.880). Median operative time was similar in both groups (150 vs. 132.5 min, p=0.665). The amount of resected tissue was lower in the RASP group (134.5 vs. 180 g, p=0.029) and there was no significant difference in postoperative PSA (1.2 vs. 0.8 ng/ml, p=0,112). Despite a similar median catheterization time (3 vs. 2 days, p=0.748), the median hospitalization time was shorter in the HoLEP group (4 vs. 3 days, p=0.052). Complication rates were similar in both groups (32% vs. 36%, p=0.987). Conclusion Our results suggest similar outcomes for RASP and HoLEP in patients with very large prostates 200ml. These findings will require external validation at other high-volume centers.

Robot-assisted sutureless partial nephrectomy for the treatment of fifteen bilateral renal masses in a patient with Von Hippel-Lindau syndrome: a case report from a high-volume robotic center

Renal cell carcinoma is among major causes of death in patients with Von Hippel-Lindau (VHL) syndrome, and it usually presents with multiple and bilateral lesions that may require multiple renal surgeries. This, in turn, may compromise renal function, resulting in end-stage renal disease. To minimize renal function impairment in these patients, great importance is given to the preservation of functional parenchyma with the use of nephron-sparing techniques. Furthermore, new techniques such as off-clamp surgery, selective suturing or sutureless techniques may improve long-term functional outcomes. We described the case of a 27-year-old male patient with a family history of VHL disease affected by multiple, bilateral renal masses. He received bilateral, metachronous robot-assisted partial nephrectomies (RAPN) for a total of 15 renal lesions. No intra- or post-operative complications occurred, and the patient was discharged on the second postoperative day after both procedures. Serum creatinine after the second RAPN was 0.99 mg/dl (baseline value was 1.11 mg/dl). In patients with VHL syndrome and multiple renal lesions, robot-assisted partial nephrectomy, especially with the use of clampless and sutureless techniques, helps minimizing renal function impairment and should be performed when anatomically and technically feasible.

Robot-assisted simple prostatectomy with the novel HUGO™ RAS System: feasibility, setting, and perioperative outcomes

Robot-assisted simple prostatectomy (RASP) has demonstrated better peri-operative outcomes as compared to open simple prostatectomy. However, RASP is still limited by platform availability and cost-effectiveness issues. The new surgical robots increasing competition may spread the robotic approach also in non-oncological fields. We reported the first RASP executed in Europe at OLV Hospital (Aalst, Belgium) performed with the novel HUGO™ Robot-Assisted Surgery (RAS) System. The platform consists of four independent carts, an open console, and a system tower equipped for both laparoscopic and robotic surgery. Our main goal was to demonstrate the technical feasibility of RASP with the novel HUGO™ RAS along with its safety in terms of perioperative outcomes and complications. We also aimed to describe our surgical setup. We collected patient's baseline characteristics, intraoperative and perioperative complications, postoperative outcomes, docking time, operative time, clashing of the instruments, or technical errors of the system. The procedure was performed in a 72-year-old male with a prostate volume of 155 g at preoperative imaging. No need for conversion to open/laparoscopic surgery and/or for additional port placement was required. No intraoperative complications, instrument clashes, or failure of the system that compromised the completion of the surgery were recorded. Docking, operative, and console times were 9, 150, and 120 minutes, respectively. The catheter was removed on the second postoperative day. No postoperative complications occurred. The postoperative uroflowmetry revealed a maximum flow of 26.2 mL/s, without postvoid residual volume. Robot-assisted simple prostatectomy with the HUGO™ RAS System is a feasible and safe procedure in terms of perioperative outcomes and complications. Our setup allowed for a rapid docking procedure and a smoothly completion of the surgery.

Observing the water handling in humans to resolve the role of the interstitium: preliminary results of the usability of deuterium oxide and bio-impedance analysis - a pilot analysis

The aim of this research was to evaluate the relevance of using deuterium oxide (²H₂O) and bio-impedance analysis (BIA) to assess size and function of the interstitium for urological research. Nineteen volunteers were recruited to this prospective trial combining ingestion of ²H₂O and BIA. Blood samples were obtained every 10 min after ingestion of ²H₂O. Urine was collected before and after the experiment. BIA was performed every 5 min. Body position was alternated to study the effect on fluid distribution. First order kinetics were assumed for the uptake of ²H₂O from the gastrointestinal tract to the blood. Sex seemed to have an influence with a significantly slower exchange for women (p = 0.041, men: 0.052 min^-1, women: 0.038 min^-1). Impedance measured in legs (men: p = 0.012, women: p = 0.008) and trunk (both p < 0.001) decreased significantly with posture change. These changes probably reflect the orthostatic redistribution of fluid with an increase of fluid in both trunk and legs. Both methods were tested and found to be useful for further urological research. Significant gender differences in ²H₂O uptake dynamics from the gastrointestinal pool were observed. An impact of posture changes on the electrical impedance measured was observed.

Incidental finding of a congenital unilateral absence of the vas deferens during robotic inguinal hernia repair: missing a crucial landmark. A case report

INTRODUCTION

We report on a case of congenital unilateral atresia of the vas deferens encountered during a robotic-assisted transabdominal preperitoneal (TAPP) inguinal hernia repair.

CASE REPORT

Our 65-years-old male patient was scheduled for a bilateral robotic-assisted TAPP inguinal hernia repair because of bilateral symptomatic groin hernia. Standard intraoperative dissection obtaining a critical view of the myopectineal orifice did not allow for an identification of the vas deferens (VD) on the left side. On the right side, a normal VD was identified. There was no suspicion of an intraoperative lesion or ligation of the VD. Both gonadal and inferior epigastric vessels were present on both sides. Upon clinical evaluation, no VD was palpable in the scrotum on the left side. The diagnosis of a congenital unilateral absence of the vas deferens was made. Additional abdominal computed tomography scan revealed a congenital agenesis of the left kidney, ureter, vesicula seminalis and vas deferens.

DISCUSSION

The accidental finding of a congenital absence of the vas deferens during inguinal hernia repair is rare. However, surgeons performing inguinal hernia repair should be aware of this condition and the clinical implications it poses, as this could prevent unnecessary exploration and missed diagnosis of associated underlying conditions.

The Influence of Salt Sensitivity Phenotype on Sodium Excretion and Diuresis: A Chrononutrition Pilot Study

BACKGROUND

Chrononutrition studies on interaction of diet/nutrients on endogenous circadian clocks and meal timing on metabolic homeostasis may be of importance in the management of nocturnal polyuria (NP), owing to loss of circadian rhythm in nighttime urination. Dietary salt restriction is an increasingly popular lifestyle recommendation for NP patients.

AIM

This study aims to evaluate the effect of an acute salt load on diuresis and to study the phenomenon of salt sensitivity. Methodology. Young, healthy men (n = 21, fasted and sober) ingested 500 ml of water on the control day and 8 g and 12 g of salt with water (500 ml) on two other days. Blood and urine samples were collected at 0 hrs, 2 hrs, and 4 hrs and voided volumes were recorded. Diuresis, serum and urine osmolality, sodium, potassium, urea, and creatinine were measured. Salt sensitivity was determined based on the rate of sodium excretion.

RESULTS

Compared to 8 g, ingestion of 12 g of salt significantly increased diuresis after 4 hrs. Pure water load induced fast diuresis, whereas salt and water load initially reduced diuresis and promoted late increase in diuresis. The total voided volume was significantly lower in the salt sensitive individuals.

CONCLUSION

Taken together, salt sensitivity profile and type and time of fluid intake are important considerations to build effective personalized lifestyle recommendations for NP patients, which needs further investigation.

Primary care providers' knowledge about the therapeutic management of refractory pelvic floor dysfunctions in Flanders, Belgium: a cross-sectional study

BACKGROUND

Pelvic floor dysfunctions (PFD) are prevalent conditions in primary care practice. Basic knowledge of second-line therapies among primary care providers (PCPs) is indispensable to well-inform refractory patients and improve their access to specialized care.

OBJECTIVES

Getting insight into the extent of knowledge about second-line therapies for refractory PFD among PCPs in Flanders, Belgium.

METHODS

From January to March 2019 Flemish PCPs participated in the OptiLUTS trial - Part A (EC/2018/0244), by the completion of a 22-item online Dutch questionnaire. Prevalence of PCPs having awareness about sacral neuromodulation (SNM), intradetrusor botulinum toxin injections (BTX) and percutaneous tibial nerve stimulation (PTNS) was explored. Descriptive statistics, univariate analyses, and multiple logistic regression analyses were performed.

RESULTS

Sixty PCPs, 55% GPs, 45% GP trainees, median age 29 years, participated. Respectively, 90, 73 and 5% had ever heard about BTX, SNM and PTNS. The profession was an independent predictive factor for never having heard of SNM therapy, GPs being more likely to have a lack of knowledge than trainees (OR = 29, 95%CI [1.9-442.5]). Ninety-three percent want to learn more about these therapies.

CONCLUSION

There is a margin for improvement in the knowledge of PCPs regarding therapies for refractory PFD. Awareness among PCPs should be increased for the optimization of patient care.

Hormone therapy as a possible solution for postmenopausal women with nocturia: results of a pilot trial

OBJECTIVE

To observe the impact of different hormonal treatment options on nocturia, its causative factors and bother in postmenopausal women.

METHODS

This prospective study recruited 245 postmenopausal women and divided them into four treatment groups based on patient's choice: Estrogen + Progesterone (E+P), Estrogen-only in patients with a prior hysterectomy, tissue-selective estrogen complex (TSEC) and no treatment. Nocturia and its causative factors were observed using two standardized questionnaires before and after treatment: the International Consultation on Incontinence Questionnaire Nocturia Module and the Targeting the individual's Aetiology of Nocturia to Guide Outcomes (TANGO). The results of the Targeting the individual's Aetiology of Nocturia to Guide Outcomes were divided in four influencing topics of which the sum score was calculated.

RESULTS

A significant reduction in prevalence of nocturia ≥ twice per night was seen after treatment, as the prevalence decreased from 27.7% (59/213) to 16.4% (35/213). Specified per therapy, a significant reduction in nocturnal voiding frequency was observed in patients treated with E+P and TSEC (P = 0.018 and P = 0.018, respectively). This improvement could be explained by a significant reduction in SLEEP sum score in patients treated with E+P and TSEC (P < 0.001, P = 0.013, respectively). Estrogen-only led to a significant change in URINARY TRACT sum score, which is the result of a reduction in urgency prevalence (P = 0.039).

CONCLUSIONS

E+P and TSEC treatment led to a significant reduction in nocturia prevalence and bother in women with ≥ 2 nocturnal voids. This effect is mainly the result of improvement in sleep disorders, however an improvement in bladder disorders can be suggested as well. More research is necessary to confirm these findings.

Nocturia through the menopausal transition and beyond: a narrative review

INTRODUCTION AND HYPOTHESIS

Nocturia, defined as the act of waking to pass urine during sleeping, is a common problem in older women and is associated with significant morbidity and impairments in health-related quality of life. The aim of this review was to synthesize the current evidence regarding the incidence, impact, pathophysiology, and specific diagnostic approach of nocturia in the postmenopausal population.

METHODS

We searched PubMed and Web of Science databases to identify relevant studies published through June 2020. Reference lists of the reviews obtained were screened for other articles deemed pertinent by the authors.

RESULTS

Genitourinary symptoms attributed to the menopause have been reported to occur in nearly 90% of postmenopausal women, and nocturia is one of the most common. The relative deficiency in endogenous estrogen production after the menopause is thought to exacerbate all major pathophysiological mechanisms that may underlie nocturia, including reduced bladder capacity, nocturnal polyuria, global polyuria, and sleep disorders. Diminished estrogen may induce anatomical and physiological bladder changes, contributing to a reduction in functional bladder capacity. Excess nocturnal urine production can also be provoked by estrogen depletion, either via free water-predominant diuresis by an impaired secretion of antidiuretic hormone, or a salt-predominant diuresis owing to diminished activation of the renin-angiotensin-aldosterone axis. Additionally, a relationship between the transition to menopause and impaired sleep has been described, mediated by increased incidence in vasomotor symptoms and obstructive sleep apnea signs during the menopause.

CONCLUSION

Further research is necessary to better characterize and manage nocturia in postmenopausal women.

Characterizing nocturia among Belgian healthy postmenopausal women: Prevalence, degree of bother, etiology and risk factors for nocturia

INTRODUCTION

Limited literature concerning nocturia in early postmenopausal women is available. However, due to the lack of endogenous estrogen in these women, an increased prevalence of nocturia is expected.

MATERIAL AND METHODS

This prospective observational trial recruited 210 'early' postmenopausal women consulting the Ghent University menopause clinic. Postmenopausal status was biochemically confirmed. Women completed 3 questionnaires: the ICI questionnaire on nocturia (ICIQ-N); 'Targeting the individual's Aetiology of Nocturia to Guide Outcomes' (TANGO) and the Perceived Stress Scale (PSS). Moreover, information concerning women's age, anthropometrics and lifestyle was collected. Nocturia was defined as two or more nocturnal voids.

RESULTS

Nocturia was reported in 24.8% (52/210) of the postmenopausal women. Bother increased with every nocturnal void. Women with two or more nighttime voids were found to have significantly increased prevalence of urgency compared with women with only one (p < 0.001; 38.5% versus 22.7%). Trouble initiating sleep at the start of the night and insomnia during the night were significantly different in women with a different nocturnal frequency (initiating sleep p = 0.09, no voids 34.4 %, 1 void 39.2 %, ≥ 2 voids 53.8 %; insomnia p < 0.001; no voids 1.6%, 1 void 22.7 %, ≥ 2 voids 53.8 %). In addition to bladder and sleep dysfunctions, waist circumference was a risk factor for nocturia (OR 1.04; 95 % CI: 1.01-1.08).

CONCLUSION

Nocturia is an important problem in early postmenopausal women, affecting a quarter of the questioned women. Etiology of nocturia in this population is multifactorial as estrogen withdrawal is accompanied by bladder and sleep dysfunctions.

Development of a flowchart reflecting the current attitude and approach towards idiopathic overactive bladder treatment in Belgium: A Delphi study

AIMS

Idiopathic overactive bladder syndrome (iOAB) is a prevalent condition in urological practice. The variability in management between specialists and between centers remains high. Even existing guidelines contain inconsistencies. We aimed to develop a treatment algorithm for iOAB for use in daily clinical practice.

METHODS

From October 2018 till November 2019, a Delphi study was conducted to obtain expert consensus on the management of iOAB. Members from the Belgian Working Group of Functional Urology were asked to rate online statements, based on gaps and variabilities between the American Urology Association (AUA), European Association of Urology (EAU) and International Consultation on Incontinence (ICI) guidelines on iOAB. The consensus was reached if ≥75% of the panel agreed on the level of appropriateness. Two Delphi rounds and an open discussion session were held.

RESULTS

Twenty out of 49 members completed the first round and 18 completed the second round. The consensus was reached on 44/143 statements and 15/56 statements in the first and second round, respectively. The consensus was reached on criteria by which to phenotype OAB patients, the terminology relating to the first-, second- and third-line treatment, the duration of therapies, the chronological order, and the choice between therapies. No consensus was reached on the role of percutaneous tibial nerve stimulation (PTNS) in the treatment algorithm.

CONCLUSIONS

A flowchart reflecting the current attitude and approach of a Delphi expert panel towards the treatment of iOAB was developed. We propose its use in daily clinical practice to increase the standardization of OAB treatment.

Nocturia and Nocturnal Polyuria in Neurological Patients: From Epidemiology to Treatment. A Systematic Review of the Literature

CONTEXT

Nocturia is among the most common and bothersome lower urinary tract symptoms (LUTS), but there is no clear consensus on how to identify and manage this symptom in the neurological population.

OBJECTIVE

To systematically review the literature about nocturia in neurological patients.

EVIDENCE ACQUISITION

Studies were identified by electronic search of Cochrane and Medline databases. The studies were included if their participants had acquired neurological pathology among multiple sclerosis (MS), Parkinson's disease (PD), stroke, spinal cord injury (SCI), and reported data on the epidemiology, aetiology, diagnosis, or treatment of nocturia. An independent extraction of the articles was performed by two authors using predetermined datasets, including quality-of-study indicators.

EVIDENCE SYNTHESIS

A total of 132 studies were included; 46 evaluated the epidemiology of nocturia, 28 the possible aetiologies, 10 the diagnostic tools, and 60 the treatments. Nocturia prevalence ranged from 15% to 96% depending on the pathology and definition used. It was one of the most frequently reported LUTS in PD and stroke patients. Several validated questionnaires were found to screen for nocturia in this population. Causalities were numerous: LUT, renal, sleep, cardiovascular dysfunctions, etc. Treatments targeted these mechanisms, with an overall risk of bias assessed as high or serious. The highest level of evidence was seen in MS patients: pelvic floor muscle training, cannabinoids, and desmopressin were effective, but not melatonin. In stroke patients, transcutaneous sacral and transcutaneous tibial nerve stimulation (TTNS) improved nocturia; in PD patients, TTNS, solifenacin, and rotigotine did not.

CONCLUSIONS

Nocturia is highly prevalent in patients with neurological disorders. Causalities and treatments are not different from the general population, but are poorly studied in neurological patients.

PATIENT SUMMARY

In this report, we looked at the published studies about nocturia-the fact of waking to void during the hours of sleep-in patients with neurological diseases. We found that nocturia is very frequent in this population, that the causes are the same as in the general population but may be combined, and that treatments are also the same but have an overall weak level of evidence. We conclude that more research is needed on this topic.

Diagnosing Nocturnal Polyuria from a Single Nocturnal Urine Sample

BACKGROUND

Patients with nocturnal polyuria (NP) experience a unique surge in nocturnal diuresis rate during the early hours of sleep.

OBJECTIVE

To determine the diagnostic utility of the volume and osmolality of a single early nocturnal urine sample in detecting NP.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of 1 am urine samples obtained from two prospective observational studies at Ghent University Hospital involving participants recruited from a urology ambulatory care unit and those who consulted a continence clinic. Nocturic participants (one or more nocturnal void[s]; n=176) were stratified based on the presence (n=87) or absence (n=89) of NP (>90ml/h).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Receiver operating characteristic curves with Youden's Index were used to determine cutoff values for urine volume and urine osmolality (Uosm).

RESULTS AND LIMITATIONS

Individuals with NP demonstrated higher 1 am volume (400 [interquartile range 300-515] vs 210 [160-300] ml, area under the curve [AUC]=0.843, p< 0.001, cutoff = 350 ml) and lower Uosm (274 [201-348] vs 430 [320-664] mOsm/kg H₂O, AUC=0.774, p<0.001, cutoff=314 mOsm/kg H₂O) than those without NP. In combining cutoffs, the criteria of either 1 am volume ≥350ml or Uosm ≤314 mOsm/kg H₂O were 85% sensitive and 75% specific for NP, while criteria of both 1 am volume ≥350ml and Uosm ≤314 mOsm/kg H₂O were 60% sensitive and 92% specific for NP. Comparable AUC values, sensitivities, and specificities were observed in both men and women. Limitations include post hoc design and a relatively small study sample.

CONCLUSIONS

Individuals with NP are more likely than those without NP to produce a higher volume of more dilute urine (ie, "aquaresis") in the early hours of sleep. Analysis of easily measurable parameters of the first nocturnal void (for which 1 am values serve as a surrogate) in men and women with nocturia can predict a diagnosis of NP with a reasonably high degree of sensitivity and specificity.

PATIENT SUMMARY

Urologists often try to understand the specific reason why people wake up to urinate at night by asking them to record the amount of urine they make every time they go to the bathroom (also known as a "voiding diary") during the nighttime as well as the daytime-typically for a total of 1-3 days. In this study, we showed that an analysis of the composition of the urine that people produce when they first wake up to urinate at night might be sufficient to determine whether their symptoms are caused by excessive urine production or something else, and some people might find this urine study easier than keeping a voiding diary.