Urinary incontinence in middle-aged women - a population-based study on prevalence, risk factors and the role of the urethra

Abstract: Urinary incontinence classification is based on symptomatology, presuming that each symptom originates in a separate pathophysiology and demands its unique therapy. Women often present a mixture of symptoms inconsistent with urodynamic diagnosis, especially regarding urgency. Treatment of stress incontinence often relieves urge symptoms indicating a common pathophysiology. Our aims were to investigate urodynamic characteristics in 59 incontinent and 28 continent middle aged women recruited from the WHILA study and to compare the findings to those of patients with established incontinence; to investigate the prevalence of LUTS including overactive bladder and potential risk factors for overactive bladder and stress incontinence. Incontinent women produced a higher maximum urinary flow and a faster flow acceleration at an unchanged detrusor pressure level than the continent women regardless of stress, urge or mixed symptomatology. They also showed a decreased ability to increase the urethral pressure during short squeezes expressed as pressure rise amplitude and in a semiquantitative classification based upon the configuration of the pressure response curve. Pelvic floor exercises increased pressure response to the same level as in continent women. Urethral pressure fall during or immediately after squeeze was significantly more common in women with established incontinence. Urgency, stress incontinence and frequency were the most common LUTS. The calculated prevalence of urinary incontinence defined as involuntary urinary leakage was 66% compared to 32% when the definition demanded social and/or hygienic bother. Overactive bladder was intimately associated with stress incontinence. Both overactive bladder and stress incontinence were associated with metabolic factors mainly increased body mass index.