The investigation and management of urinary incontinence (UI) has exhibited a major gender bias in favor of women. Important movements in women's health have resulted in comprehensive clinics addressing all aspects of health including bladder control, but similar movements in men's health have been limited. Further, research in men has primarily focused on diagnosis and treatment of erectile dysfunction rather than UI or closely associated bothersome lower urinary tract symptoms. Funded research on incontinence is based predominantly on female populations. Less is known about the epidemiology of UI in men because it has not been investigated to the same extent as for women. Indeed, most studies on UI in men focus only on incontinence after radical prostatectomy, indirectly implying the unlikelihood of other causes. Although UI is more prevalent in young adult women as compared to young adult men, this gap narrows with age, especially in advanced age groups (>75 years and over, Stenzelius, Mattiasson, Hallberg, & Westergren, 2004). However, most studies report prevalence rates of UI to be less in men than in women by a 1:2 ratio (Hunskaar et al., 2002). Epidemiologic studies of overactive bladder dysfunction (a symptom syndrome characterized by daytime voiding frequency, nocturia, and bothersome urgency) reveal comparable prevalence rates up the 6th decade of life, and higher prevalence in men aged 65 years and older (Stewart et al., 2003;Milsom, Stewart, & Thuroff, 2000).

A recent survey of men in four different cities in France, England, Korea, and Holland reported the incontinence rate in men over 60 as ranging from 8% in Seoul to 23% in Birmingham (Boyle et al., 2004). The authors posit that cultural rather than actual differences led to the different prevalence rates. In Spain, a population survey and interview of people over 65 indicated a prevalence for incontinence of 14% in men and 30% in women, noting that few had sought assistance for the problem (Zunzunegui Pastor et al., 2003). These percentages are similar to those reported in the NOBLE study (Stewart et al., 2003) in which Americans matched for sex and age were surveyed for the prevalence and burden of overactive bladder. Frequency and urgency, with or without incontinence, were equally reported by men and women for an overall rate of 16.5%. The prevalence increased with age: 10% of men over 75 reported urge incontinence and 22% over the age of 55 reported frequency, nocturia, and urgency, without incontinence, suggesting a protective mechanism of the prostate. Men with bothersome lower urinary symptoms had decreased quality of life scores, higher depression scores, and interrupted sleep. In subgroup analysis, nocturia, traditionally thought to be an indicator of prostatism, was equal in both men and women as their age increased. Loss of sleep from nocturia was significantly correlated with decreased socialization, increased symptom bother, and increased seeking of medical care (Coyne et al., 2003).

Incontinence is debilitating and ranked higher than erectile dysfunction as impacting quality of life (Temml, Haidinger, Schmidbauer, Schatzi, & Madersbacher, 2000). The personal distress of UI includes an associated economic cost. The total cost of diagnostic studies and treatment for UI, including surgical and pharmacological therapies, is reported as $16.3 billion in the United States ($3.8 billion for men after prostatectomy) and at least 1 billion dollars annually in Australia (Wilson, Brown, Shin, Luc, & Subak, 2001). The average cost per incontinent individual living in the community is estimated to be $1848 US per year (Rohner & Rohner, 1997). The majority of this expense stems from incontinence supplies.

Given the psychosocial and economic consequences of incontinence and similar prevalence rates among women and men, the apparent gender bias in research is difficult to explain. In this article, we explore what is known about incontinence in men and attempt to highlight some of the gaps in this knowledge, address limitations in the current research, and consider directions that continence care may take in 2004 and beyond.

Urinary Continence

In the male, urinary continence requires neuromuscular control of the detrusor muscle and competence of the urethral sphincter mechanism (Gray, 2002). Detrusor muscle control relies on modulation by neural pathways, the actions of neurotransmitters at neuromuscular junctions within the detrusor, and the biomechanics of the bladder wall (de Groat & Yoshimura, 2001). During bladder filling and storage, modulatory centers interact with neurons in the periaqueductal gray matter of the brainstem to ensure relaxation of the detrusor muscle and contraction of muscular elements of the urethral sphincter. During micturition, inhibitory influences from the brain are removed, and the pontine micturition center provokes the simultaneous detrusor contraction and sphincter mechanism relaxation needed for complete evacuation of urine. The urethral sphincter mechanism is a combination of compressive and muscular elements that prevent urine loss during bladder filling and storage. Compressive elements of the sphincter mechanism include soft, moist urethral epithelium and underlying vascular structures designed to form a watertight seal under the influence of smooth and striated muscular contraction. The muscular elements of the sphincter mechanism incorporate smooth muscle bundles within the bladder base, bladder neck, and proximal urethra. In addition, continence arises from striated muscle within the urethral wall, the rhabdosphincter and periurethral pelvic floor muscles (Elbadawi, 1996). The rhabdosphincter is exclusively comprised of slow-twitch (Type I) muscle fibers; the periurethral muscles contain a combination of slow- and fast-twitch (Type II) fibers. Fast-twitch fibers may be voluntarily activated on sudden, increased abdominal pressure created by coughing, laughing, or sneezing. Slow twitch fibers provide the sustained tone needed for maintenance of continence during prolonged periods of bladder filling and urine storage. In both men and women, the proportion of striated muscle fibers in the urethra and bladder neck appears to decrease with advancing age (Perucchini, Delancey, Ashton-Miller, Galecki, & Schaer, 2002;Strasser et al., 1998) and may partly explain why the risk of stress UI increases with age.

Etiology of Incontinence in Men

In addition to increasing age, other factors for incontinence present themselves: neurological diseases (Parkinson's disease, multiple sclerosis, spinal cord injury, and stroke), detrusor overactivity, loss of mobility and dexterity, and cognitive changes. A history of radiation therapy, urethral or pelvic trauma, spinal cord lesions, and medications will also play a role (Kondo et al., 2002;Litwiller, McIntire, Schnitzer, & Roerborn, 1997;Staskin, Vardi, & Siroky, 1988). The relationship between prostate enlargement, lower urinary tract dysfunction and UI risk in the aging male is only partly understood (Gray, 2002;Knutson, Edlund, Fall, & Dahlstrand, 2001;Roberts et al., 1998). One study of elder males found prostate enlargement to be protective of continence (Umlauf & Sherman, 1996). Many studies have noted that prostate surgery (either radical prostatectomy or more limited resection in cases of benign hyperplasia) is associated with an increased risk of UI (Gray, Petroni, & Theodorescu, 1999;Kuo, 2002;Porru et al., 2001; Umlauf & Sherman). Obstruction caused by benign or malignant prostatic enlargement alters both local and central modulation of detrusor control, decreases detrusor contraction strength, impairs cellular regulation, and increases expression of several nerve growth factors resulting in hypertrophy of the bladder wall and an increased risk for incomplete bladder emptying (Delancey et al., 1999). The resulting changes lead to overactive bladder dysfunction and detrusor overactivity that may increase the risk for UI when the obstruction caused by prostate enlargement is surgically corrected (Chai, Gray, & Steers, 1998;Knutson et al., 2001;Kageyama et al., 2000). Changes in detrusor contraction strength are also associated with diabetes mellitus, chronic alcohol abuse, and possibly smoking. None of these etiologic factors should be overlooked when obtaining a patient history. They represent complex issues rather than "simple" overactive bladder symptoms more common in women and require assertive problem-solving to ameliorate. The complex conditions may explain in part why trials of anticholinergic or antimuscarinic medications exclude male patients.

Incontinence and Prostate Cancer

Loss of bladder control is rare in the young man unless it is associated with neurologic disease, injury, or surgery. The most common major procedure that can affect continence is treatment for early stage prostate cancer by radical prostatectomy or brachytherapy. In 2004 nearly 200,000 men in the US will be diagnosed with prostate cancer and 40,000 will die of it, making it second only to lung cancer in cancer-related deaths. The three treatment options are radical prostatectomy, external beam radiation therapy, and interstitial radioisotope seed implant. The two major sequelae associated with prostate cancer treatment are erectile dysfunction and UI.

The request for a radical prostatectomy is common and in the US thousands of men a year undergo this surgery (Smith, 1994). After radical prostatectomy, the prevalence of lifelong incontinence requiring the daily use of incontinence pads ranges from 5% (Poon et al., 2000) to 45% (Bishoff et al., 1998) depending on the definition of incontinence and how data was collected. While men and their wives develop specific coping strategies in the short term and can accept incontinence as a time-limited entity (Maliski, Heilemann, & McCorkle, 2002; Maliski, Heilemann, & McCorkle, 2001), those who suffer from incontinence are affected in a major way, feeling despondent, depressed (Herr & Middleton, 1994;Hunskaar & Sandvik, 1993), and in the extreme, suicidal (Moore & Estey, 1999).

After radical prostatectomy (laparoscopic or retropubic), the male continence mechanism and the controlling nerves are structurally damaged. While proximal sphincteric injury is the primary cause of incontinence, an overlooked cause is detrusor instability (Foote, Yun, & Leach, 1991). Preoperative PSA, Gleason score, seminal vesical invasion, preoperative urinary symptoms, and patient age are also relevant. Surgical expertise (Eastham et al., 1996) and having surgery in a hospital that performs fewer than 20 radical prostatectomies a year are also related to continence outcomes (Albertsen, Lu-Yao, & Warren, 1997).

The incidence of incontinence after brachytherapy or external beam radiation is lower than after radical prostatectomy (Merrick, Butler, Wallner, Galbreath, & Lief, 2003). Wei and colleagues (2002) note, however, that in long-term follow up, the differences in outcomes on quality of life and continence status are not significantly different between brachytherapy, radical prostatectomy, or external beam therapy. Of note is that smokers are at a higher risk of incontinence after brachytherapy than non-smokers, possibly due to the nicotine-associated microvascular changes (Merrick et al.). There are no qualitative studies assessing continence after brachytherapy nor are there studies which systematically evaluate pre- and posttreatment continence status after brachytherapy. Such studies are required so that patients can make informed decisions about treatment choices.

Treatment of Incontinence

Pelvic Floor Muscle Exercises

Pelvic floor muscle exercises (PFMEs) are the mainstay for the treatment of postprostatectomy incontinence. The theoretical basis of PFME is that repeated, volitional contractions of selected pelvic floor muscles may improve urethral sphincter closure during periods of increased intra-abdominal pressure (Berghmans et al., 1998). Currently, the lack of well-designed randomized studies in men mean that protocols for UI treatment are extrapolated from studies in women (Payne, 1998). Because of the significant difference in etiology in males and the complexity of the associated risk factors, the accepted continence theories in women may not automatically transfer to men.

Whether PFME impacts the return to continence after radical prostatectomy is not well understood. In comparison to over 100 well-randomized controlled studies on female UI, currently only nine have been published on incontinence after radical prostatectomy. The evidence to support PFME after radical prostatectomy is modest at best (Hunter, Moore, Cody, & Glazener, 2004). One Belgian study of note compared PFME with biofeedback to standard verbal instruction immediately after catheter removal (Van Kampen et al., 2000). Actively treated subjects achieved continence significantly more quickly than the control group although the difference was not significant at 12 months postsurgery. Despite limitations of a number of treatment protocols (biofeedback, home exercises, electrical stimulation, bladder retraining) and no preoperative continence measures, it was the first study to systematically evaluate very early intervention postsurgery. Further well-designed studies testing conservative treatment should be undertaken and early versus delayed intervention explored in the treatment of incontinence after radical prostatectomy (Canadian Continence Foundation, 2000; Kondo et al., 2001).

Pelvic floor muscle exercise programs are typically labor-intensive and costly, directed by nurses or physiotherapists who specialize in pelvic floor therapy. No direct comparison of the effectiveness of PFME directed by intensive therapy versus nonspecialized therapy using verbal coaching and written materials has been done in men. Assessment in women, for example, has indicated that there is no difference in outcome in traditional PFME compared to PFMEs incorporating transversus abdominalis muscles (Dumoulin, Lemieux, Bourbonnais, & Morin, 2003). Incontinence treatment in men deserves similarly sophisticated and informative studies.

Lifestyle Interventions

Healthy bladder habits and lifestyle interventions such as exercise, weight loss, bladder training, smoking cessation, caffeine reduction, adequate fluid intake, and regular bowel movements are all recommended as part of healthy living. The direct relationship to treatment of UI is unsubstantiated but staying healthy certainly prevents or delays the onset of co-morbid conditions such as diabetes or arteriosclerosis, which are risk factors for UI. Thus primary prevention of bladder dysfunction should play a role in healthcare in the same way that providers are now paying attention to prevention of obesity and smoking.

Bladder training, a traditional conservative treatment for urge UI, has been studied in women but, despite almost equal incidence of overactive bladder symptoms in the older age group, no studies have addressed men with urgency. Even in women, the evidence to support bladder training is modest (Wallace, Roe, Williams, & Palmer, 2004) and further well-designed trials are required for both sexes.

Pharmacotherapy

Research on antimuscarinics and anticholinergics such as oxybutynin and tolterodine has had predominantly female samples with urodynamically demonstrated detrusor instability or symptom scores suggestive of overactive bladder. Systematic assessment of medication effectiveness is required in older men, particularly those with comorbid conditions that are clinically representative of their age groups.

Future Directions

Although numerous studies have explored the psychosocial impact of UI in women and their subsequent help-seeking patterns, relatively little is known about the impact on men. In the UREPIK study on prevalence of incontinence in men (Boyle et al., 2004), those with a partner were less likely to report incontinence, a finding that requires further exploration on the importance of caregiver or spousal involvement. The authors also report that despite reporting leakage, less than 26% of men overall, and in Seoul only 9%, had sought assistance from their physician. Those who reported severe incontinence were more likely to seek assistance but even so, less than half had sought assistance. Similar findings were reported by Milne (2003) who noted that once incontinence interfered in a major way with daily activities, men were more likely to be assertive in seeking assistance and to adhere to a treatment protocol such as PFMEs or bladder retraining. The attitudes of men toward incontinence and, more importantly, toward help-seeking, require further exploration so that primary healthcare programs can be designed to meet the needs of those who require continence care.

The onset of detrusor dysfunction in the patient with diabetes has not been well-explored despite the prevalence of diabetes and the known risk of bladder decompensation with the disease. Up to 13% of seniors in the US will have diagnosed diabetes, primarily Type 2, and as many more remain undiagnosed (Bertoni, Anderson, Krop, & Brancati, 2002). Diabetic cystopathy, with an estimated prevalence of 32-45% (Ueda, Yoshimura, & Yoshida, 1997), has received almost no attention. This disparity persists despite the prevalence of associated urinary tract infections, renal complications, cost to the healthcare system, and impact on optimum health. No published long-term studies assess voiding function at early diagnosis or over the course of the disease, and there is little information on the changes at the cellular level that contribute to contractility changes. A recent study evaluating detrusor density and [beta]-adrenergic function in obstructed diabetic animal models noted significant changes when compared to non-diabetic obstructed bladders (Longhurst, Levendusky, & Bezuijen, 2004). Thus prostatic obstruction may speed the process of denervation leading to incomplete bladder emptying in the patient with diabetes.

Existing gaps in UI research in men (Table 1) highlight the necessity for basic science, translational, and clinical research. Application of basic science research in neuroscience and molecular biology provides multiple opportunities to enhance our understanding of bladder dysfunction in the male (Morrison et al., 2002) and multiple pathways for nurses to participate in translational research needed to advance these observations from the laboratory to the clinical setting. For example, advances in our understanding of cellular responses in the lower urinary tract to obstruction will provide opportunities for translational research studies that address the short- and long-term implications of aggressive (surgical) versus conservative (pharmacologic) treatment of benign prostatic hyperplasia, particularly when it is associated with overactive bladder dysfunction. Similarly, stem cell research has led to improvements in rhabdosphincter function in animal models and lends support for the hypothesis that injection of stem cells in the human rhabdosphincter may increase sphincter competence following radical prostatectomy (Berjukow et al., 2004). Confirmation of this research-based hypothesis is important for nursing research because it may provide an effective adjunctive to the pelvic floor muscle rehabilitation following prostate surgery.

TABLE 1.

At the clinical level more information is needed on bladder-related symptoms men experience, the impact of behavioral and pharmacological/surgical intervention, and the perceived psychosocial costs. Perhaps most importantly, accessibility of continence care for the male population must be explored and enhanced. As health services for women move forward, men needing continence care must not be left behind.

In conclusion, in spite of the growth in research related to UI following radical prostatectomy, numerous gaps in our understanding of UI in men remain. Many men with incontinence do not seek help for their condition, yet millions suffer because of the problem. Research exploring men's experiences with incontinence and the cultural or personal reasons for not seeking assistance will help healthcare professionals understand the perceived or real barriers. If the barriers are appreciated, then proactive care for men can be implemented at the primary healthcare level. Complimenting the basic science research with qualitative assessments will go far to enhancing understanding about men's experiences with incontinence and expectations for treatment. Finally, healthcare professionals need to be proactive themselves, asking people about lower urinary tract symptoms and initiating assessments that lead to early intervention and treatment.

References