Epidemiology and etiology

BPH is present as microscopic disease in many elderly males.1 The prevalence increases with advancing patient age. However, only about 50% and 25% of patients with microscopic BPH disease develop an enlarged prostate on palpation and clinical voiding symptoms, respectively.2 It is estimated that 25% of males 40 years of age or more have voiding symptoms consistent with BPH, and 20% to 30% of all male patients who live to the age of 80 years will require a prostatectomy for severe voiding symptoms of BPH.2

Two etiologic factors for BPH include advanced patient age and the stimulatory effect of androgens.

• Prior to 40 years of age, the prostate in the adult male stays the same size, approximately 15 to 20 g. However, in males who have reached 40 years of age, the prostate undergoes a growth spurt, which continues as the male advances in age. Enlargement of the prostate can result in clinically symptomatic BPH.

• The testes and adrenal glands produce 90% and 10%, respectively, of circulating testosterone. Testosterone enters prostate cells, where predominantly type II 5a-re-ductase activates testosterone to dihydrotestosterone, which combines with a cyto-plasmic receptor. The complex enters the nucleus and induces changes in protein synthesis which promote glandular tissue growth of the prostate. Thus, 5a-reductase inhibitors (e.g., finasteride and dutasteride) directly interfere with one of the major etiologic factors of BPH.

• The prostate is composed of two types of tissue: (a) glandular or epithelial tissue, which produces prostatic secretions, including prostate-specific antigen (PSA) and (b) muscle or stromal tissue, which can contract around the urethra when stimulated. Whereas androgens stimulate glandular tissue growth, androgens have no direct effect on stromal tissue. It has been postulated that stromal tissue growth may be stimulated by estrogen. Since testosterone is converted to estrogen in peripheral tissues in males, testosterone may be associated indirectly with stromal hyperplasia. Stromal tissue is innervated by a1A-receptors. When stimulated, prostatic stroma contracts around the urethra, narrowing the urethra and causing obstructive voiding symptoms.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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