The role of estrogen supplementation in lower urinary tract dysfunction

The female lower urinary and genital tracts both arise from the primitive urogenital sinus and develop in close anatomical proximity. Sex hormones have a substantial influence on the female lower urinary tract throughout adult life, with fluctuations in their level leading to macroscopic, histological and functional changes. Urinary symptoms may therefore develop during the menstrual cycle, in pregnancy and following the menopause. Estrogen deficiency, particularly when prolonged, is associated with a wide range of urogenital complaints, including frequency, nocturia, incontinence, urinary tract infections and the 'urge syndrome'. Estrogen supplementation subjectively improves urinary stress incontinence but there is no objective benefit when given alone; however, estrogen given in combination with phenylpropanolamine may be clinically more useful. Hormone replacement therapy does appear to treat postmenopausal irritative urinary symptoms such as frequency and urgency, possibly by reversing urogenital atrophy, and there is also evidence to suggest that estrogens can provide prophylaxis against recurrent urinary tract infections. However, the 'best' type of estrogen, route of administration and duration of therapy are at present unknown.