2015-02-25

Benign prostatic hypertrophy (BPH), also known as benign prostatic hyperplasia, is a common adverse health condition typically seen in aging men. It is associated with lower urinary tract symptoms that affect quality of life by interfering with daily activities and normal sleep patterns. The prevalence of BPH has been shown to increase with age.  It is present in approximately 8% of men aged 31-40 years, 50% of men aged 51-60 years, 70% of men aged 61-70 years and 90% of men aged 81-90 years.

The prostate gland is located just below the bladder, surrounding the urethra. Its main role is to produce a thick liquid that makes up a substantial portion of the seminal fluid, or semen. Muscles in the prostate help move semen through the ejaculatory duct; and also help open the bladder to allow urine to pass through the urethra. Thus, a healthy prostate gland performs both sexual and urinary functions.

Enlarged prostate or BPH is the abnormal but non-cancerous growth of prostate cells. Half of all American men over age 60, and most over the age of 70, typically experience one or more symptoms of an enlarged prostate. As the prostate grows larger, it pushes against the urethra and bladder, blocking normal urinary flow. Even a slight enlargement of the prostate can lead to significant obstructive symptoms. Urinary storage symptoms are usually a result of instability in the bladder. An increase in the size of the prostate raises intravesicular pressure, so the bladder adapts by increasing in size. When its muscles become too large, the bladder becomes hypersensitive and unstable, causing urinary storage symptoms.

The prostate gland produces DHT by converting testosterone in the presence of an enzyme called 5-alpha reductase. Together, testosterone and DHT along with estrogen promote a balance between cell growth (proliferation) and death (apoptosis) in the prostate gland. However, as men age and their testosterone levels fall, DHT levels remain high, suggesting that this imbalance may be responsible for BPH development. Some studies suggest that men who do not produce DHT typically do not develop BPH. Estrogen may also play a role in the growth of prostate cells in aging men.

Typical symptoms of BPH include:

Frequent urination

A sudden, uncontrollable urge to urinate

Difficulty starting a urine stream, leading to hesitancy and straining

Weak flow of the urine stream

Dribbling after urination

Feeling that the bladder is not completely empty

An urge to urinate again soon after urinating

Pain during urination, known as dysuria

Waking at night to urinate, known as nocturia

In a few cases, BPH may even completely block the bladder, making it nearly impossible to urinate. Chronic urinary retention over time can lead to bladder infections, kidney stones and kidney damage.

Risk factors for BPH include:

Being older than 50 years

Levels of the male hormones testosterone and DHT and the female hormone estrogen

High intake of polyunsaturated fatty acids and red meat, especially beef

Hypertension or high blood pressure (BP)

Level of physical activity, which is inversely proportional to the risk of BPH and lower urinary tract symptoms

Body weight, body mass index (BMI) and waist circumference, which exhibit a linear relationship with prostate volume

Elevated levels of fasting plasma glucose, which influence prostate growth; also, elevated insulin levels, which are associated with increased prostate volume

Alcohol consumption - which may have a protective effect on BPH development, likely related to its cardiovascular effects and ability to modulate steroid hormone metabolism.

Diagnostic tests for BPH include a urine test (urinalysis) and a digital rectal exam, which lets the physician assess the size and tenderness of the patient’s prostate. In some cases, a prostate-specific antigen (PSA) test can help in diagnosis: the higher the PSA level, the more likely is the diagnosis of prostate cancer. However, there can be other reasons for having elevated PSA levels and some men who have prostate cancer do not show elevated PSA levels.

When BPH causes only mild symptoms, healthcare practitioners may advise ‘watchful waiting,’ a term used to describe frequent testing to monitor changes in the prostate gland. Health practitioners may also recommend lifestyle changes, as well as herbal medicines and supplements. If symptoms start to worsen, treatment should be considered because severe BPH can lead to serious health problems over time, including permanent bladder damage. Men who experience any symptoms of BPH, however minor, are usually advised to see their healthcare practitioner to be evaluated for the most serious prostate condition, which is prostate cancer. Medical treatment is usually reserved for men who have significant symptoms.

Available drugs include:

Alpha blockers, which relax the smooth muscles of the prostate and the bladder neck, helping to relieve urinary obstruction caused by an enlarged prostate. Side effects can include headaches, fatigue, problems ejaculating or lightheadedness. These drugs generally will lead to improvement in symptoms within several weeks, without having any effect on prostate size.

5-alpha reductase inhibitors block conversion of testosterone into its active form DHT in the prostate. Prostate enlargement in BPH is a direct consequence of DHT levels, so these drugs lead to a reduction in prostate size over 6-12 months. Side effects may include declining interest in sex, erectile dysfunction and problems with ejaculation.

Surgical procedures may also be used to treat BPH, most commonly in men who have not responded satisfactorily to medication or those who have developed more severe problems, such as a complete inability to urinate. These include:

Transurethral resection of the prostate (TURP)

Laser procedures, involving the removal of obstructing prostate tissue and generally associated with less bleeding and quicker recovery than TURP; however, they may not be as effective over the long term.

Microwave therapy, involving the use of microwave energy delivered to the prostate to kill some of the cells, leading eventually to shrinkage of the prostate.

Men with BPH should carefully weigh the risks and benefits of each of these options. Prostate surgery has traditionally been seen as offering the most benefits, but unfortunately also carries the most risks.

Reference

https://www.clinicalkey.com/topics/urology/benign-prostatic-hyperplasia.html

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