專題討論13:更年期以後之婦女疾病
Disorders of Postmenopausal Women

S13-2
Urinary disorder with aged menopausal women
Yung-Kuei Soong, MD, M. Phil (London)
Vice Superintendent
Professor, Department of Obstetrics and Gynecology
Chang Gung Memorial Hospital
Linkou Medical Center
Chang Gung University Medical College

  Ageing is a continuous and inevitable process that affects everyone. One of the most important age-related changes affecting the lower urinary tract is the postmenopausal decline in the estrogen. In addition, the lower urinary tract is greatly influence by the interactive and additive effects of age-related changes and the accumulation of many pathologic entities with increasing age. Symptoms of lower urinary tract dysfunction are common in elderly women.
At any age, continence depends not only on the integrity of lower urinary tract function, but also on the presence of adequate mentation, mobility, motivation, and manual dexterity. Incontinence in elderly patients is commonly associated with deficits outside the urinary tract. A patient with impaired mobility may develop urinary incontinence if suitable access to a toilet is not available. It is crucial to detect them.

  In addition to recognizing the important factors outside the urinary tract, it is important to realize that the lower urinary tract itself change with age. Bladder capacity, the ability to postpone voiding, urinary flow rate, maximum urethral closure pressure and urethral length appear to decline in women. Both the prevalence of uninhibited contraction and the post-voiding residual volume are likely increase. Another important change is an alteration in the pattern of fluid excretion. Many elderly people excrete bulk of their daily ingested fluid during the night, even those who do not have metabolic disorder, heart failure, or renal disease. This fact, coupled with an age-associated increase in prevalence of sleep disorders, leads to episodes of nocturia in healthy elderly individuals. In addition, the ageing population is at risk for a number of systemic illnesses and transient problems that may present with lower urinary tract symptoms, including diabetes mellitus, congestive cardiac failure and renal disease. Therefore, symptoms of overactive bladder are prominent in elderly population.
Detrusor overactivity is the leading lower urinary tract cause of incontinence in older individuals. Although distinctions are commonly drawn between detrusor overactivity that is associated with a central nervous system lesion (detrusor hyperreflexia) and that which is not (detrusor instability). Traditionally detrusor overactivity has been though to be the primary urinary tract cause of incontinence. Recently detrusor overactivity in the elderly has been found to exist as detrusor hyperactivity with impaired contractility, and it is the most common caused of established incontinence in frail elderly persons. It is associated with urinary urgency, frequency, weak flow rate, and significant residual urine.

  Stress incontinence is the second most common cause of incontinence in older women. As in younger women, it is caused most often by pelvic muscle laxity. A less common cause is intrinsic sphincter deficiency or type 3 stress incontinence. Usually owing to operative trauma and urethral atrophy could be the causes. In addition to leaking with stress maneuvers, ISD may dribble even when sitting or standing quietly.

  Detrusor underactivity sufficient to cause urinary retention and overflow incontinence occurs in only about 5% to % of older women. The symptoms of sever detrusor underactivity may mimic those of detrusor overactivity such as urgency, frequency and nocturia, and so exclusion of urinary retention is mandatory before initiating treatment of detrusor overactivity.
Urinary tract infections occur in women of all age. They are a particular problem in the elderly, with a reported incidence of 20% in community-dwelling women and sometimes over 50% in institutionalized patients. Pathophysiological changes that account for the increase in risk include impairment of bladder emptying, poor perineal hygiene and both fecal and urinary incontinence. Furthermore, alterations in the vaginal flora after menopause are also thought to place women at an increased risk for UTI., particularly if they are sexually active.

  In conclusion, the age, menopause and subsequent oestrogen deficiency have been implicated in the pathogenesis of a number of urogenital problems including incontinence, the urge syndromes, and recurrent UTIs. In addition to conventional treatments on lower urinary tract dysfunction, hormone treatment does appear to improve irritative urinary symptoms of frequency and urgency and may be on the extent of urinary incontinence. Treatment for several weeks or even months may be needed for maximum efficacy.