New research into links between men who exhibit signs of
hair loss, and prostate size has been carried out in India.
Findings appear to have uncovered a positive correlation between men affected by male pattern baldness and enlarged prostates. Though, backing up previous research, the doctors involved note that certain hair loss treatments may help to protect the prostate.
Causes of male pattern baldness
The Miniaturisation Process: How DHT Shrinks Hair Follicles
Androgenetic alopecia (AGA - better known as
male pattern baldness) is the most common form of hair loss in the world, affecting two-thirds of the UK population alone. It is an hereditary condition that presents as thinning hair along the top of the head and can also cause a
receding hairline.
The reason people predisposed to genetic hair loss find the hair in these areas gradually thinning out over time is due to an androgen hormone in the body known as
DHT (dihydrotestosterone).
DHT, also known as 5α-dihydrotestosterone (5α-DHT), is produced when the enzyme 5α-reductase reacts with testosterone in the prostate, testes, hair follicles, and adrenal glands. Its most important role is in helping the body to develop sexual characteristics during puberty.
After this time, in those with a genetic predisposition to male hair loss, it can bind to hair follicles, weakening them and slowly turning terminal - healthy - hairs into wispy vellus hairs. This displays outwardly as
thinning hair and/or receding. The process is known as follicular miniaturisation and also causes an increase in shedding as well as leading to baldness in some cases.
Causes of benign prostatic hyperplasia
Benign prostatic hyperplasia (BHP) is extremely common and is caused by an enlargement of the prostate gland, which is located between the penis and the bladder and is responsible for producing semen. According to the NHS, approximately 40 per cent of men over 50, and 75 per cent of men in their 70s have urinary symptoms of an enlarged prostate.
Whilst it can lead to urinary infections and retention in some cases, these are considered 'complications'. The majority of men with BHP will simply experience difficulties in starting urination or fully emptying their bladder; they may also need to urinate more frequently. These symptoms are caused as the prostate gland swells in size, pressing on the bladder.
Despite myths to the contrary, an enlarged prostate is not linked to an increased chance of developing prostate cancer: the risk is the same for those who are affected as those who are not.
There is not yet any definitive evidence confirming precisely what causes prostate enlargement but it is widely believed by the medical community to be related to hormonal changes that occur as men age.
Shared pathogenesis
The new study, published in the
International Journal of Trichology, concentrated on finding an association between those affected by male pattern hair loss and BPH as the two conditions are believed to have a shared pathogenesis. That is to say they are thought to develop in the same way.
The research paper states that the team's initial thinking was:'Because both entities share a common pathogenesis and AGA manifests before the onset of BPH, there could be an association between AGA and BPH.'
In order to test this theory 65 men, aged between 35 and 65 years of age with an overall mean age of 47.18, with AGA had their prostates measured via ultrasound. The participants' hairloss was classified between III - VII on the
Hamilton-Norwood Scale, where these grades represent moderate to severe levels of male pattern baldness. Anyone with less advanced
signs of hair loss was excluded from the study, as were men using
hair loss treatments and/or who had a history of prostate-related cancer or disease.
The reason for excluding men using hair loss treatments, especially
finasteride 1mg, the oral MHRA licensed and FDA approved medication clinically-proven to treat male pattern baldness, is that its job is to inhibit DHT formation. Finasteride is, in fact
derived from a BPH medication; it is simply taken in far smaller doses.
The results showed that a Hamilton Norwood Scale classification of IV was the most common, with 19 patients (29.2%) in this category. Of those 19, the majority - 47.4% - were aged between 5665 years. Overall 52.3% of the whole group of participants had what is considered a normal prostate volume, whilst 47.7% were found to have an enlarged prostate.
From the participants with a Norwood classification of III, the most moderate level of thinning studied, the majority of men - 68.8% - had a normal prostate. Just over a third of the group had an enlarged prostate. However, when looking at the subset of participants with advanced hair loss measuring a Norwood VI, the ratios had almost reversed with 66.7% of the group having an enlarged prostate. The correlation between the progression of male pattern hair loss and prostate size was therefore considered to be significant.
In concluding their research, the Indian team explained, ' found a positive correlation between AGA and prostate size, with higher grades of AGA having higher prostate volume, which can be attributed to their common etiopathogenesis: Androgens and the enzyme 5-alpha reductase which is expressed both in the prostate and dermal papillae of scalp hair. Therefore, finasteride, a 5-alpha reductase type 2 inhibitor used to treat control AGA, may probably be useful in delaying the onset of BPH and its associated symptoms. Further studies are needed to evaluate this hypothesis. In addition, AGA develops much earlier than enlargement of the prostate. Hence, AGA of early onset may be considered as a biomarker for BPH later in life.'