Evaluation of the association between asthma and non-neurogenic urinary incontinence in children; a case-control study

Asthma is the most common chronic respiratory disease in children worldwide, and if it is not properly controlled, it can lead to stunted growth, higher healthcare costs, and even increased mortality [1]. The quantity and quality of a child’s sleep can be negatively impacted by diseases such as asthma, which frequently cause nocturnal symptoms. Asthma is associated with poor sleep quality, even in children with persistent and well-controlled symptoms [2].

Non-neurogenic urinary incontinence (UI) is the second most common condition in childhood, after allergic diseases, and is described as the unintentional loss of urine that cannot be attributed to any other organic cause or medicine [3]. Bladder and bowel dysfunction can often lead to this condition, and vice versa [4].Children acquire consistent bladder control at about 3 years old, first during the daytime and later at night [5; 6]. Wetting is pathologic in children who are old enough to control their bladder. UI in children is associated with emotional discomfort, behavioral issues, and diminished quality of life [7]. Two distinct forms of UI can be identified by the time they manifest: nocturnal enuresis, which occurs at night while sleeping, and daytime UI, though a combination of both types is also possible [8]. There are several urinary disorders associated with UI.

UI can be associated with several comorbidities. Constipation has been shown to have a strong association with UI in children. Studies show that up to 40% of children with UI also have constipation [9]. UI in children can also be linked to respiratory disorders such as sleep apnea. Children with sleep apnea are more likely to experience UI, and treating it can improve bedwetting [10]. In addition to physical comorbidities, UI has been also associated with psychological and psychiatric disorders like attention-deficit/hyperactivity disorder (ADHD), anxiety, and depression [11; 12].

Since asthma may cause sleep-related breathing problems [13], and since UI, particularly nocturnal enuresis, is associated with sleep-related breathing disorders [14], a relationship can be found between UI and asthma. In addition, asthma is a chronic condition in children, and most chronic diseases in children are associated with psychiatric disorders such as ADHD, depression, and anxiety [15]. Because most psychiatricl illnesses are correlated with UI [11; 16], it is conceivable that asthma is also associated with UI. On the other hand, several studies show a connection between allergic diseases and UI [17; 18]. The goal of this study is to evaluate the association between asthma and urinary disorders associated with urinary incontinence so that, if a relationship is found, children with asthma can be screened for these conditions and given treatment.

This research was a case-control study with 314 children over three years old, including 157 children with asthma and 157 children without asthma or a history of asthma symptoms who were referred to the pediatric clinic of Amir Kabir Hospital. Parents of children who visited were questioned about their child’s asthma symptoms and history. If a child exhibits asthma symptoms, such as wheezing in the lungs, cough, and shortness of breath, as well as a history of using inhaler sprays, the diagnosis of asthma is made after the confirmation of pediatric asthma and allergy specialist and the child is then included in the case group. The control group participants were randomly selected from children over three years old with no symptoms of asthma or allergies, a personal or family history of asthma or any other respiratory diseases which mimic asthma symptoms, as well as a history of anatomical disorders in Kidneys and urinary tracts, or neurogenic disorders. After receiving the consent of the child’s parents to participate in the study, the types of urinary disorders, symptoms, and features of each disorder were explained. All disorders and their symptoms were thoroughly described to the patients and their parents based on the International Children’s Continence Society’s definitions [19]. Then the parents or child were questioned about the presence of each disorder. The urinary disorders included MNE and NMNE, VR, pollakiuria, infrequent voiding, GI, and OAB.

MNE is a condition in which a child or adult experiences involuntary urination during sleep at least twice a week, without any other urinary symptoms during the day or any other medical conditions [20]. Nonmonosymptomatic nocturnal enuresis (NMNE) consists of nocturnal symptoms along with lower urinary tract symptoms, such as urgency, changes in voiding frequency, and holding maneuvers, with or without daytime incontinence [21]. Nocturnal enuresis with any severity (mild: less than once a day or less than 7 times a week, moderate: more than once a day or 8–20 times a week, severe: more than 20 times a week [22]) was considered positive. Giggle incontinence (GI) is described by total or involuntary bladder emptying while giggling or laughing, with normal bladder function at other times [19]. vaginal reflux (VR) or intravaginal urination is one of the causes of UI in prepubescent girls, which is accompanied by post-void dribbling, vulvovaginitis, vaginal discharge and foul smell around the vagina [23]. Pollakiuria is defined by extremely frequent daytime urination, urinating every 15 to 20 min without nocturnal enuresis, dysuria, and urinary tract infections [24]. Children with infrequent voiding (underactive bladder) are usually female, and they urinate just twice per day, whereas the normal frequency of urination is 4–7 times per day [25]. Overactive bladder (OAB) is a syndrome characterized by urinary urgency, associative with urinary frequency and nocturia, in the absence of any local pathological causes [19].

The presence or absence of UI in children was determined by the child’s or parents’ perception. The researcher then entered the resulting data, which included the child’s asthma status, UI status and type, age, and gender, into a checklist.

The analysis was performed by the stata software version 16. In the descriptive section of this study, frequency, percentage, mean, and standard deviation were utilized. In addition, to compare quantitative and qualitative variables, the independent t-test and analysis of variance were considered if the data had a normal distribution, whereas the Mann-Whitney U test was used if the data did not have a normal distribution. To compare two qualitative variables, Chi-Square test or Fisher’s exact test were used. Additionally, logistic regression was utilized to calculate the odds ratio.