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Arch Dis Child doi:10.1136/archdischild-2012-301867
  • Short research report

Dysfunctional voiding in children with asthma

  1. Tutku Soyer3
  1. 1Department of Pediatric Allergy, Hacettepe University, School of Medicine, Ankara, Turkey
  2. 2Department of Pediatrics, Ministry of Health, Ankara Education and Research Hospital, Ankara, Turkey
  3. 3Department of Pediatric Surgery, Kirikkale University, School of Medicine, Kirikkale, Turkey
  4. 4Department of Pediatric Surgery, Ankara University, School of Medicine, Ankara, Turkey
  1. Correspondence to Dr Ozge Uysal Soyer, Department of Pediatrics Allergy, Hacettepe University, School of Medicine, Ankara 06100, Turkey; ozgeusoyer{at}gmail.com
  • Received 15 February 2012
  • Revised 31 December 2012
  • Accepted 10 January 2013
  • Published Online First 2 February 2013

Abstract

A prospective study was performed to evaluate the prevalence of suspected dysfunctional voiding (DV) and associated risk factors in children with asthma. The DV is defined as any voiding symptoms and/or urinary incontinence. Children (4–10-year-old) with asthma (n=178) and healthy subjects (n=197) were enrolled. DV and Incontinence Scoring System were administrated. Demographic features and asthma related characteristics were recorded. Suspected DV was noted in 19 (27.9%) of patients with asthma and 5 (6.6%) of healthy subjects in children younger than 6 years of age (p=0.001). In this patient group, asthma increased the risk of suspected DV (OR=5.7 (95% CI 1.988 to 16.344)). Children with asthma older than 6 years of age had similar prevalence of suspected DV but they had higher frequency of voiding and urgency. Asthma is associated with higher DV symptom scores in younger children who have already completed toilet training and with some of DV symptoms such as frequency and urgency in older children.

What is already known on this topic

  • Dysfunctional voiding may be a comorbid condition accompanying diverse chronic diseases during childhood.

What this study adds

  • The paediatricians dealing with asthma should take into consideration the risk of dysfunctional voiding symptoms in children with asthma to prevent complications.

  • Asthma is associated with higher DV symptom scores in younger children.

Introduction

Dysfunctional voiding (DV) is a common clinical problem and accounts for nearly 40% of paediatric urological visits. The term DV is used to define any child with voiding symptoms and/or urinary incontinence.

Asthma is a chronic inflammatory disease characterised by variable airway obstruction and recurrent symptoms.1 Increased intra-abdominal pressure due to chronic cough and dyspnoea may be associated with asthma. Our clinical observation suggests that children with asthma may have higher existence of voiding symptoms. Since prevalence and risk factors for DV in children with asthma have not been investigated previously, we performed a prospective study to define the prevalence of suspected DV in children with asthma and its determinants.

Methods

Children with asthma aged 4–10 years were recruited from the paediatric allergy department. The diagnosis of asthma was made with a history of intermittent wheezing, and/or reversible airway obstruction as defined by at least a 12% improvement in forced expiratory volume in one second following bronchodilator administration.1 Healthy subjects were enrolled from paediatric outpatient clinics without a history of atopic diseases as confirmed by the International Study of Asthma and Allergies in Childhood questionnaire.

We used a survey concerning demographic features (age, gender, parents’ education level and history of urinary tract infection) for children with asthma and healthy controls. We noted asthma control parameters (scheduled and unscheduled visits due to asthma, emergency department visits and hospitalisation due to asthma in the last year) in the patient group. Children with asthma and their parents filled the Turkish version of the Childhood Asthma Control Test (C-ACT). A C-ACT score of 19 or lower indicated inadequately controlled asthma. The physician also assessed the level of asthma control as ‘controlled’, ‘partly controlled’ or ‘uncontrolled’ based on clinical control parameters as suggested by the Global Initiative for Asthma Guideline.1

All children were administered the Turkish version of the DV and Incontinence Scoring System (DVISS).2 Children with a DVISS score greater than 8.5 were diagnosed as ‘suspected DV’. The study was approved by the Local Ethics Committee and written informed consent was obtained from parents.

Statistical analysis

The results were analysed with SPSS V.15.0 (SPSS, Inc, Chicago, Illinois, USA). Differences between children with asthma and healthy subjects were compared by Student's t test or Mann-Whitney U test or χ2 test as appropriate. Variables with a p value of less than 0.25 in univariate analysis were examined in the multivariate logistic regression models. The size of the effect of each of the risk factors was measured using the OR and 95% CI. A value of p≤0.05 was considered statistically significant.

Results

We collected data from 178 children with asthma and 197 healthy children. The demographic features of children are summarised in table 1.

Table 1

The demographic features

Sixty-eight of patients with asthma were younger than 6 years of age and 110 of them were older than 6 years of age. Children younger than 6 years of age with asthma (41%) had higher prevalence of enuresis nocturna (EN) than healthy children (15.8%) (p=0.001). In children younger than 6 years of age, suspected DV was diagnosed in 19 (27.9%) patients with asthma and 5 (6.6%) healthy subjects (p=0.001) (table 2). Logistic regression analysis for suspected DV in children younger than 6 years of age included gender, education level of parents, history of urinary tract infection, history of urinary tract disease and asthma, and revealed that asthma increased the risk of diagnosis of suspected DV (OR=5.7 (95% CI 1.988 to 16.344, p=0.001)).

Table 2

Voiding parameters in children

Children with asthma older than 6 years of age had similar prevalence of suspected DV and EN symptoms (p>0.05) compared with healthy children but they had higher frequency of voiding (>7 times/day) (29 (26.4%) and 17 (13.9%), p=0.018) and had higher prevalence of urgency (36 (32.7%) and 25 (20.5%), p=0.035) (table 2).

In children with asthma (younger and/or older than 6 years of age), logistic regression analysis for risk factors for suspected DV concerned asthma control parameters, level of asthma control (‘uncontrolled’ vs ‘partly controlled and controlled’), gender, atopy, type of atopy (perennial vs seasonal, presence of house dust mite sensitivity), serum IgE levels, peripheral eosinophil per cents, C-ACT score (score≤19) and anti-inflammatory drug use. However, there was no association of suspected DV with any of the risk factors we analysed in children with asthma.

Discussion

Asthma is a common chronic disease of airways characterised by chronic cough and wheezing. In this study, we demonstrated an association between asthma and DV symptoms in children with asthma who required further investigation especially in children younger than 6 years of age.

Incontinence results when intra-abdominal pressure is higher than urethral pressure. Patients with asthma may have increased intra-abdominal pressure as a result of increased pressure gradient between thorax and abdomen. In Canadian adults aged 30 years or older, asthma increased the risk of urinary incontinence (OR=1.35 (95% CI 1.00 to 1.95, p<0.05)).3 However, Shariat et al,4 reported no difference in prevalence of stress urinary incontinence in patients with chronic cough due to allergic rhinitis, sinusitis or asthma in comparison with subjects without chronic cough. In our study, the prevalence of daytime incontinence was similar in children with asthma and healthy children but prevalence of EN was higher in children with asthma younger than 6 years of age when compared with healthy controls.

Coyne et al,5 have shown in a cross-sectional, population-based study that asthma is one of the most common comorbid conditions for lower urinary tract symptoms and assessed as a risk factor for DV symptoms in adults. In our study, children with asthma younger than 6 years of age had higher prevalence of suspected DV but in older children, we were not able to demonstrate a similar finding. These results suggest that presence of asthma contributes to higher DV symptom scores in children who had already completed their toilet training. However, among all DV symptoms, only higher prevalence of frequency and urgency were observed in older children. It is difficult to make a firm conclusion about the underlying pathophysiology of DV symptoms in children with asthma. In order to define a clear relationship, further urological investigations are required.

We hypothesised that there might be increased DV symptoms in children with uncontrolled asthma since repeated coughing and forced expirations may place further stress on the pelvic floor. We evaluated asthma related risk factors for DV; however, none of the surveyed parameters such as asthma control parameters, asthma control levels and severity were related to DV in asthma.

Screening of DV with a symptoms-scoring system obtained by a questionnaire is a simple, time-saving and widely used approach in clinical settings.2 Invasive techniques such as urodynamics are required for definitive diagnosis of DV and are reserved for selected patients.2 Therefore, we assessed DV symptoms with DVISS in this descriptive study which is one of our limitations. The data collected in this study were mainly based on information reported by the parents.

In conclusion, asthma and DV are common clinical entities during childhood. Asthma may increase DV symptoms in children. Paediatricians and paediatric allergy specialists should be aware of this condition and may use DVISS to decide the need for urology consultation. The early diagnosis and appropriate treatment of DV will prevent complications including upper urinary tract infections, vesicoureteral reflux and even renal failure.

Acknowledgments

This study was presented at the European Academy of Allergy and Clinical Immunology Congress in 2011 in Istanbul, Turkey, and was awarded the best poster presentation.

Footnotes

  • Contributors OUS participated in the development of the protocol and analytical framework of the study, outcome assessment and prepared the manuscript and had primary responsibility for patient screening in her study centre. TS participated in the development of the protocol and analytical framework of the study, outcome assessment and prepared the manuscript. MC had primary responsibility for outcome assessment and data analysis, and prepared the manuscript with OUS and TS. BK, MFS, MKA and YD supervised the design and execution of the study, contributed to preparation of the manuscript, and had primary responsibility for patient screening in their study centres.

  • Competing interests None.

  • Ethics approval Ethics Committee of Ministry of Health, Ankara Education and Research Hospital.

  • Provenance and peer review Not commissioned; externally peer reviewed.

References