Stress Urinary Incontinence in Women

Removing the Barriers to Exercise

Giovanni Elia, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 27 - NO. 1 - JANUARY 1999

In Brief: Stress urinary incontinence—urine loss that follows a sudden increase in intra-abdominal pressure—is common in women and can be a major barrier to exercise. It often occurs with a cough or sneeze, routine activities, or exercise and is caused by derangement of the pelvic supportive structures as a result of aging, birth trauma, or collagen defects. Initial evaluation should consist of a thorough history that includes a voiding diary, a pelvic exam, and, possibly, a cough stress test. Referral for urodynamic testing may be necessary. Conservative therapies such as intravaginal or barrier devices and/or pelvic muscle strengthening techniques are often effective and should be tried before surgical repair is considered.

A growing number of women are exercising and thereby gaining benefits ranging from an improved sense of well-being to increased cardiovascular endurance, musculoskeletal strength, and mobility. But as more women have formed the exercise habit, more attention has been focused on complaints of stress urinary incontinence (SUI) during physical activity.

The prevalence of SUI was suggested by a recent survey (1) in which 28% of a group of nulliparous elite athletes reported experiencing the problem during exercise. For women who are troubled by incontinence while working out, effective treatment may be essential to enable them to continue their regimen. Thus an understanding of SUI and the wide range of available treatments is important for fitness-oriented physicians.

Definitions and Types

The International Continence Society (ICS) has defined urinary incontinence (UI) as the "involuntary loss of urine which is objectively demonstrable and a social and hygienic problem (2)." UI in general is of two kinds: that related to abnormalities of the storage phase, and that related to abnormalities of the voiding phase. SUI is storage-phase urine loss that follows a sudden increase in intra-abdominal pressure without concomitant bladder contraction. Other subtypes of UI and their characteristics are listed in table 1.

Table 1. Types of Urinary Incontinence
Type	Characteristics
Storage Phase
Stress	A sudden increase in intra-abdominal pressure without concomitant bladder contraction that overcomes pelvic support and results in urine loss
Bladder or detrusor instability	Uninhibited bladder contractions during bladder filling
Mixed	A combination of stress and bladder (detrusor instability) incontinence
Bypass	Related to anatomic abnormalities that bypass the urethral sphincteric mechanism (eg, vesicovaginal fistula,urethral diverticulum, ectopic ureter)
Voiding Phase
Overflow	Often a result of urethral obstruction resulting in constant leakage from a continually full bladder

Prevalence

Each year in the United States, $16 billion is spent on incontinence-related care and $1.1 billion on disposable absorbent products for adults (3). For cultural and social reasons, the prevalence of UI is difficult to assess, but it has been estimated that 13 million Americans, 11 million of them women, are incontinent, and that among women 30 to 59 years old, 25% have experienced UI (3). Among individuals under 25 years old, large epidemiologic studies have suggested that the prevalence of UI is between 3.0% and 4.2% (4,5). And, in a selected population of women with a general complaint of UI, the prevalence of SUI has been estimated at between 50% and 75% (6).

The problem of SUI in physically active women has been addressed in recent years by several authors (1,7-12). Bø et al (7) reported that 13 (35%) of 37 female physical education students (aged 18 to 27), reported having SUI, and 8 (62%) of those affected considered it a social or hygienic problem. In a survey (1) of 144 elite nulliparous athletes, 28% (40) experienced UI during exercise, and 27% (123) of female soldiers in another study (11) had UI during field activity. Among 290 patients in one gynecologic practice who reported exercising regularly, the rate was 30% (87), and 20% (17) of those had stopped exercising because of incontinence (8).

The risk of incontinence in women involved in sports is greater with high-impact activities (figure 1: not shown). The prevalence is higher in basketball than in volleyball, for example (1), possibly because the running jumps in basketball result in greater impact than the more controlled jumping in volleyball.

Pathophysiology

Currently, the pathophysiology of SUI is considered to be multifactorial. The main explanations involve derangement of the pelvic supportive structures because of aging or birth trauma or defects in collagen composition.

Muscle weakness. DeLancey (13), after meticulous dissection of female cadavers and study of biomechanical models, has formulated the "hammock hypothesis." He suggests that the vaginal wall and the endopelvic fascia support the urethra and bladder neck like a hammock, attaching laterally to the tendinous insertion of the levator ani muscle (arcus tendineus fasciae pelvis, also called the "white line" of the pelvis, figure 2). These structures, it is suggested, provide a posterior support against which the urethra is compressed in the presence of increased intra-abdominal pressure. If this support weakens, increased pressure will cause the urethra to descend and open, resulting in incontinence.

The anatomic support of the pelvic organs provided by the levator ani is particularly important in humans because of bipedal posture. The chronic pressure of gravity on the pelvic support is acutely increased during daily activities, coughing, sneezing, and exercise.

Neuromuscular damage. A second proposed factor in SUI is neuromuscular damage. Studies on nerve conduction have found substantial denervation at the level of the pelvic muscles in women who have given birth by vaginal delivery (14-17). The aging of neuromuscular structures is thought to play a role in the development of pelvic floor support dysfunction or to unveil a subclinical deficiency. The proved (although not consistent) efficacy of pelvic muscle exercises appears to confirm this theory (18,19).

Weakened collagen. One more factor that has been thought to affect the development of UI and pelvic relaxation is the collagen composition in the supportive structures of the pelvis. In one study, six women who had SUI were found to have weaker collagen than eight normal controls (20). This observation seems to place UI in the category of genetic disorders.

The composition and strength of collagen is also affected by the presence of estrogens: Lack of estrogen, as in menopause, results in weaker collagen (21). Estrogen deficiency alone, however, does not explain the occurrence of UI. A study (22) of young women who had premature ovarian failure did not reveal a significant difference in urodynamic parameters before and after estrogen replacement.

Thus it appears that UI in young competitive athletes cannot be attributed to exercise-related amenorrhea unless some other predisposing condition is present.

In summary, then, it appears that aging of the neuromuscular structures is an element in the development of SUI, and that pelvic ligamentous supportive structures work in concert with the muscles and nerves to provide continence. Hormonal milieu and genetic predisposition also play a role in the development of UI, but further studies are needed to improve our knowledge.

Evaluation

In view of the ICS definition of UI, diagnostic workup (table 2) and treatment should be reserved for women whose condition is subjectively bothersome. Symptoms of UI should be evaluated in the context of the general health and lifestyle of each patient. Clinically significant UI may be related, in younger women, to increased physical activity. For example, a teenager involved in competitive sports may have occasional UI during strenuous training, whereas her more sedentary friends do not have the problem. On the other hand, physical fitness and mobility in older individuals may help prevent incontinence: An elderly woman with severe arthritis might not experience UI if she could promptly reach the toilet (23).

Table 2. Components of the Standard Evaluation for Urinary Incontinence History Impact of incontinence on daily activities Precipitators (eg, exercise, coughing, sneezing, walking, standing, lifting) Associated urgency or urge incontinence Use of diuretics, alpha-blockers, or beta-blockers Diseases (eg, chronic obstructive pulmonary disease, neuropathy, diabetes mellitus) Voiding diary (2 to 7 days) Physical Exam Levator ani contraction strength Degree of pelvic relaxation Genital organ estrogenization Sensation to pinprick, pressure, vibration Anal and clitoral reflexes Postvoid residual Cough stress test Pad test (optional)

History. Studies on incontinence and exercise (1,8,11,12) confirm that the vast majority of women who have exercise-related SUI also complain of loss of urine during other activities, such as routine daily activities. Accordingly, evaluation of women who have UI during exercise should include assessment of the impact of incontinence on their daily activities. Questions should be asked about loss of urine on coughing, sneezing, walking, standing up, and lifting, in addition to exercising.

Women may have symptoms of stress incontinence only, or an associated sudden, strong need to void (urgency) with loss of urine (urge incontinence). Any history of urgency is important because, in such patients, cystoscopy with urodynamic testing may be necessary.

The medical history may disclose information such as the use of diuretics or alpha- or beta-blockers; a history of chronic obstructive pulmonary disease, neuropathy, or diabetes mellitus is also of great importance, although rare in a younger population.

Voiding diary. Often underestimated is the social history. Knowing the time and amount of caffeine or alcohol intake may be essential in the treatment of UI and other urinary problems. Therefore, an invaluable tool to obtain a more objective picture of the patients' voiding and drinking habits as well as the frequency of incontinence episodes is the voiding diary. This should be completed over 1 week, but since many women find that length of time difficult, 2 or 3 days may be a good compromise. The voiding diary should include calculation of total fluid intake, amount and type of beverages (coffee, soda, juice, etc), volume voided, and number and circumstances of incontinence episodes.

Physical examination. Whether sedentary or active, women who have SUI should be evaluated for anatomic and structural derangement of the pelvic supportive structures. After a detailed history, a urine dipstick test is necessary to screen for infection or other bladder or renal pathology. Bladder catheterization should then be performed no more than 5 minutes after voiding to measure the postvoid residual and thus rule out voiding dysfunction.

To rule out a subclinical neuropathy, a neurologic exam targeted to assessment of the S-2 through S-4 levels of the spinal cord should be performed. This is easily achieved by testing pinprick, pressure, and vibration sensation in the vulva, perineum, and inner thighs and by assessing the anal and clitoral reflexes (figure 3). Genital organ estrogenization and degree of pelvic relaxation, if any, should also be evaluated.

During the pelvic exam, care should be taken to assess the strength of the levator ani and the patient's ability to contract the pelvic floor muscles without using accessory muscles and without performing Valsalva's maneuver. This information can be very helpful in deciding if a subject is a candidate for pelvic floor muscle exercises.

A scale using grades 0 to 5 has been developed for a more objective assessment of the power of the pelvic floor muscles. Grades are assigned from findings as follows: no contraction, grade 0; flicker, grade 1; weak, grade 2; moderate, grade 3; good, grade 4; or strong contraction, grade 5 (24).

In a woman who has SUI, the loss of urine can be objectively demonstrated with a cough stress test. The patient is asked to cough while in a standing position with a full bladder. The diagnosis is made by observing loss of urine from the urethra exactly at the time of the cough. This assessment, and the urine loss reported in the voiding diary, should be sufficient to quantify the severity of the problem.

When a more precise assessment is required, as for research purposes, a pad test is necessary (2). This is done by measuring the changed weight of a pad that the subject has been wearing during standard activity for 1 hour. Although accurate in a laboratory setting, this test was found to have a 68% error in clinical practice (25).

This basic evaluation will be sufficient to start a management plan (table 3). If the patient reports irritative symptoms such as urgency, frequency, or dysuria in the absence of urinary infection, a urethrocystoscopy may be warranted. A stronger indication for urethrocystoscopy is the association of the above symptoms with microscopic hematuria or a history of smoking.

Table 3. Conservative Treatment Options for Stress Urinary Incontinence in Active Women Preexercise voiding Caffeine avoidance Alcohol avoidance Use of extrinsic intravaginal support during exercise or as needed:    Tampon    Pessary    Bladder-neck-support prosthesis (eg, Introl) Use of barrier devices (eg, Impress,    FemAssist, CapSure) during exercise or as needed Pelvic muscle strengthening/retraining:    Pelvic muscle exercises    Vaginal cones    Biofeedback    Electrical stimulation

Further evaluation with urodynamic tests is necessary with failure of conservative management, severe pelvic relaxation with urogenital prolapse at the level of the vaginal introitus or lower, previous anti-incontinence surgery, history of radiation therapy, history or physical findings of neurologic dysfunction, or when surgical correction is planned.

Treatment

Treatment for SUI should be based on the main symptoms of the individual patient. If the main problem is UI during exercise, lifestyle measures and various devices may help. Pelvic muscle strengthening is also helpful for many patients with SUI, whether the condition is exercise-related or not.

Lifestyle measures. Voiding before starting exercise is practiced by many women with incontinence. In some patients, however, a voiding dysfunction may be present as indicated by a high postvoid residual, and such patients do not gain any benefit unless they perform self-catheterization after voiding. These patients should be referred for urodynamic testing.

Avoiding coffee and other caffeinated beverages for 2 to 3 hours before exercise will prevent diuresis, thus decreasing bladder filling. Some women tend to dramatically reduce their fluid intake before exercise. This habit should be strongly discouraged because it may cause severe complications from dehydration (11).

Intravaginal support devices. Intravaginal support devices can be used during exercise or at other times as necessary. In two clinical trials (26,27), intravaginal pessary use was found to vary in effectiveness from 36% to 83% of individuals participating (5 of 14 and 10 of 12). The use of a vaginal tampon was found to be effective in 57% of subjects (8 of 14) (27). Success with the use of intravaginal devices, whether tampon or pessary, was correlated with the severity of UI as measured by pad test (27).

An innovative intravaginal device is the Introl bladder-neck-support prosthesis (UroMed Corporation, Needham, Massachusetts). This device resembles a pessary but has two projections that fit under the urethra to support it (figure 4). The device was effective in 83% (25) of 30 physically incontinent active women involved in a clinical trial (28).

The hammock theory may explain the success of intravaginal devices for preventing
UI during exercise. These devices support the urethra and bladder neck, preventing descensus of these structures and reconstituting the continence mechanism. Unfortunately, this type of treatment is not universally effective.

Barrier devices. Among the most recent treatment options for SUI during exercise are three barrier devices (figure 4): Impress Softpatch (UroMed, Needham, Massachusetts), FemAssist personal urinary control device (Insight Medical Corporation, Bolton, Massachusetts) and CapSure continence shield (Bard Urological Division, Covington, Georgia). These disposable devices are placed at the external urethral meatus and kept in place by an adhesive surface (Impress) or by suction (FemAssist and CapSure). They prevent urine loss by obstructing the external urethral meatus; the devices must be removed to void.

Pelvic muscle strengthening. Pelvic muscle exercises are a well-established treatment option for UI and are effective in 50% to 60% of women with SUI. Exercises can be started without a definite diagnosis so long as overflow incontinence is ruled out (19). To do so, a postvoid residual measurement may be sufficient.

Contraction exercises. The goal of pelvic muscle contraction exercises is to increase the tone and strength of the levator ani. For best results, patients should be instructed during the pelvic exam and should be involved in a program of close follow-up and practice under observation at office visits.

Many methods of doing the exercises exist, all of them similarly efficacious. The one we favor consists of a series of 5-second contractions followed by 10 seconds of relaxation, performed for 10 minutes four times a day. This is an intensive program that should be continued for 3 months with frequent office visits. If the results are satisfactory, a maintenance regimen of exercises once or twice a day should be continued indefinitely. It is essential to make sure that the pelvic muscle contraction is performed without a Valsalva maneuver or accessory muscle involvement (19).

Vaginal cones. The use of vaginal cones is also aimed at strengthening the levator ani (29). The patient buys a set of cones of the same size but different weights. She is instructed to start with the lightest cone and hold it in the vagina for about 20 minutes once or twice a day. As her levator ani becomes stronger she uses heavier cones. This method has the advantage of requiring less instruction and reinforcement, but it can be used only in a private environment.

Biofeedback. Another technique is biofeedback (30), a signal that makes the individual aware of physiologic changes in response to a voluntary action. The simplest biofeedback technique is a statement about the strength of the patient's contraction of the pelvic floor muscles, made by the examiner during a pelvic exam.

Slightly more sophisticated feedback is achieved with a perineometer. This instrument measures increased intravaginal pressure in response to pelvic muscle contraction. The measuring probe is a small cylindrical balloon placed in the vagina. The pressure gauge is placed in front of the patient so that she can observe the magnitude of her effort. More complex biofeedback units measure electrical changes in pelvic muscle fibers and display the data on a high-resolution monitor.

Electrical stimulation. This is a relatively new technique for the treatment of SUI. It usually involves a device that is inserted into the vagina and delivers a faradic current whose amplitude and frequency can be adjusted according to patient sensation and comfort. The current causes an involuntary contraction of the pelvic floor muscles, allowing retraining and strengthening of the structures. The results with this technique have been reported to be promising (31,32).

Beyond Conservative Treatment

If a diagnosis of SUI has been confirmed and conservative management has been unsuccessful, and if further treatment is desired, surgical management should be discussed extensively with the patient.

References

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Dr Elia is director of the division of urogynecology in the department of obstetrics and gynecology at the State University of New York Health Science Center at Syracuse, New York. Address correspondence to Giovanni Elia, MD, 736 Irving Ave, 3 West Tower, Syracuse, NY 13210; e-mail to giopaula@dreamscape.com.