Breathlessness is associated with urinary incontinence in men: A community-based study

Urinary incontinence (UI) is a distressing condition and costly problem for older adults [1]. Established risk factors of UI are age, gender, obesity and smoking [2‐4]. The prevalence of UI is also known to be higher among women with cystic fibrosis, 30.4% to 68% [5‐7], than the general population of 10.4% to 23.9% [8‐10]. Cough is the major cause of UI among 80 to 90% of females with cystic fibrosis, as frequent coughing may lead to imbalance within the muscles of abdomino-pelvic capsule [11]. The leakage of urine occurs when intra-vesical pressure exceeds urethral closure pressure in the absence of a detrusor contraction, or due to bladder neck hyper-mobility or poor urethral closure pressure [12]. In the literature, focus has been directed to females and coughing whereas investigation on incontinent males is scant [1]. A recent population-based study in the USA reported that men with asthma had twice the odds of leakage, especially for White men [13]. The purpose of this study is to ascertain the relationship between UI and respiratory symptoms in middle-aged and older community-dwelling men. The finding should be beneficial for the prevention and treatment of this irritating condition.

For the 668 participants, their average age was 62.7 (standard deviation (SD) 7.5; range 43 to 82) years and mean BMI was 23 (SD 3.1; range 14.5 to 37.8) kg/m². Most of the men were married (87.6%) and 35% of them had retired. A substantial proportion of subjects smoked (26.3%) and consumed alcohol (70.7%) on at least a monthly basis.

The prevalence of UI was 7.6%. Table 1 presents the characteristics of subjects by UI status. The incontinent men were three years older on average and had significantly higher prevalence of respiratory symptoms than those without the condition, especially for breathlessness (45% versus 30%, p = 0.025). The binary breathlessness outcome was validated against the Medical Research Council's dyspnoea score. The observed spearman rank correlation of 0.7 confirmed a good agreement between the two scales. The observed dyspnoea score was also higher among the incontinent men, but the two groups were similar with respect to other co-morbidities and physical activity involvement.

Table 2 summarises the ICIQ-SF outcomes. Urine leakage among the 51 incontinent subjects was typically "a small amount" (84.3%) and occurred once a week or less often (58.8%). The mean ICIQ-SF total score was 6 (SD 2.7) and no one considered the condition to have interfered with their daily life to a great extent. The most common occurrence of urine loss was before reaching the toilet (number (n) = 33, 64.7%). While 30 (58.8%) of the incontinent men experienced urge incontinence, six (11.8%) sustained stress-type leakage, two (3.9%) had mixed and 13 (25.5%) reported other types. On average they had urine leakage for 2.5 (SD 1.8) years with a maximum duration of 10 years.

The proportion of men affected by UI increased from 6.4% without to 11% with breathlessness. Results of logistic regression analyses are given in Table 3, which confirmed all three respiratory symptoms were associated with increase in prevalence of UI. In particular, the adjusted odds ratio (OR) of 2.11 (95% confidence interval (CI) 1.10-4.06) was significant for breathlessness, even after accounting for individual's age, BMI, smoking and alcohol drinking status. Moreover, none of the five health conditions were found to be significant, while the effect of breathlessness was not modified by the inclusion of these co-morbidities into the multivariate model. The correlation between the ICIQ score and the dyspnoea score was 0.24. However, the dose-response effect of dyspnoea on UI was not significant (adjusted OR = 1.17, 95% CI 0.90- 1.51).

This study provides the first report of the relationship between UI and respiratory symptoms among middle-aged and older men. Breathlessness was found to be associated with UI. A cross-sectional study of 7,947 community-dwelling women in the USA reported that faster gait speed (≥ 1.04 meter/second) was related to decreased daily UI (OR 0.8, 95% CI 0.6-1.0) compared with lower gait speed (< 0.86 meter/second) [19]. Although walking slowly may not necessarily imply breathlessness, people who can walk fast are unlikely to suffer from breathlessness.

For women with cystic fibrosis [11] and asthma [13], stress incontinence has been related to their chronic coughing and sneezing which raise intra-abdominal pressure and cause damage to the pelvic floor [13]. Unlike women, urge-type leakage was most common among our sample of incontinent men. The observed association with breathlessness can be attributed to the continence mechanism, especially neurological control of the pelvic floor and micturation [11]. The nerve supply of the pelvic floor is via the pudendal nerve, as part of the somatic nervous system. Bladder filling and storage of urine involves autonomic control via the sympathetic system and bladder voiding is under parasympathetic control [11]. Meanwhile, breathlessness is under the sympathetic system. People who feel breathlessness are more likely to have an imbalance between sympathetic system and parasympathetic control, or may have less parasympathetic control. Once leakage occurs there is a chronic and progressive deterioration of the pelvic neuromuscular function [5].

Some limitations of the study should be considered. Classification of UI status was based on self report via the ICIQ-SF rather than objective measurements of urine loss. Despite the subjective perception of the condition, it is now recognised that the use of psychometrically robust self-completion questionnaires is a valid approach for assessing UI. The ICIQ-SF has good measurement properties and encompasses all aspects of incontinence [14, 15, 20]. Moreover, face-to-face interviews were conducted by the same investigator to avoid misinterpretation of the questions and to reduce inter-interviewer bias. All participants resided in the community and should be representative of the underlying population. Selection bias might still exist because these voluntary participants were not randomly selected. The observed association could be confounded by the presence of co-morbid conditions. The lack of confirmation of other co-morbidities such as benign prostatic hypertrophy was another limitation of the study. Physical activity and several self-reported health conditions were not associated with urine leakage and thus unlikely to be confounders. Nevertheless, population-based prospective cohort studies are needed to confirm the apparent cause-and-effect relationship between UI and breathlessness. Experimental research to further understand the underlying biological mechanism is also important.

The present study has highlighted the additional burden that breathlessness can impose on middle-aged and older men. Education and regular assessment for UI are recommended, and treating respiratory symptoms should become part of the routine health management of older adults to prevent the development of this distressing condition.