Benign Prostatic Hyperplasia
Written by Ramita Kaur Shahi
Last Reviewed: September 2019
Review Due: September 2020
DEFINITION
'a non-cancerous enlargement of the middle portion of the prostate gland, with formation of discrete nodules in the periurethral region of the prostate'
AETIOLOGY
Unknown but may be due to hormonal changes that occur as males grow older.
Risk Factors:
Aging
Family history
Diabetes
Obesity
Heart disease
Use of beta blockers
SIGNS AND SYMPTOMS
Difficulty starting and stopping stream
Increased frequency of urination
Inability to empty the bladder completely
Weak urine stream
Bladder hypertrophy and distension
Overflow dribbling
Nocturia
Dysuria
Urinary tract infection
PATHOPHYSIOLOGY
Testosterone is converted to Dihydrotestosterone (DHT) by type 2 5-alpha-reductase located in the stromal cells of the prostate gland.
DHT has a higher affinity than testosterone for androgen receptors (AR) in the stromal and epithelial cells of the prostate gland.
Binding of DHT to AR activates the transcription of genes that result in increased production of several growth factors and their receptors. This results in increased stromal cell proliferation, decreased epithelial cell death and formation of well-defined nodules (hallmark of BPH). These nodules then compress the walls of the urethra into a slit-like orifice.
Investigations
laboratory
Urine dipstick
White cells would suggest infection potentially precipitated by BPH
U&Es
Baseline kidney function
Prostate Specific Antigen (PSA)
Elevated with enlarged prostate
Urinary flow test
Measures strength and amount of urine flow
Post-void bladder scan
Measures ability of the bladder to empty completely
24-hour voiding diary
Record frequency and amount of urine. Helpful if more than 1/3 of daily urine output occurs at night
May be considered:
Transrectal ultrasound
Prostate biopsy
Urodynamic and pressure flow studies
Cystoscopy
Other investigations
TREATMENT
Treatment of BPH depends on:
Size of prostate
Age
Comorbidities
Severity of symptoms
For some, symptoms may be tolerable or ease without treatment.
For mild to moderate symptoms, where conservative management has been unsuccessful.
Alpha blockers (Alfuzosin, Doxazosin, Tamsulosin, Terazosin)
Relaxes smooth muscles of the bladder and prostate, allowing smoother passage of urine.
5-alpha reductase inhibitors (Finasteride)
Inhibits conversion of testosterone to DHT, thus reducing the proliferation of stromal and epithelial cells of the prostate.
Offered when patient is symptomatic with prostate larger than 30g or PSA > 1.4 ng/ml.
Anticholinergics
To manage symptoms of overactive bladder.
Oral desmopressin
If nocturnal polyuria present with other medical causes excluded and other treatments fail.
Transurethral resection of the prostate (TURP)
Lighted scope inserted into the urethra and all of outer part of prostate removed.
Transurethral incision of the prostate (TUIP)
Lighted scope inserted into the urethra and one or two small cuts made in the prostate. Offered if prostate is smaller than 30g.
Medical treatment
Surgical treatment
EPIDEMIOLOGY
Incidence in the UK ranges from 150 to 420 cases per 1,000,000 people.
BPH tends to affect men above the age of 50. Approximately 43% of men above the age of 65 and 90% of men in their seventies and eighties have urinary symptoms due to BPH.