Men who take medication to reduce their symptoms of prostate disease may be more likely to develop type 2 diabetes, research suggests.
Patients with enlarged prostates who are prescribed drugs called 5-alpha-reductase inhibitors are around a third more at risk of the condition.
They reduce the production of androgens, a hormone which help to boost urinary flow, a common problem among men with enlarged prostates.
But these drugs - which include finasteride and dutasteride - may slow metabolism and reduce the body's insulin sensitivity, which can trigger type 2 diabetes.
Finasteride made headlines in 2017 when Donald Trump's doctor Harold Bornstein revealed the President takes the controversial drug to combat baldness.
Prostate-disease sufferers who take a commonly-prescribed drug to help them urinate are a third more at risk of type 2 diabetes, research suggests (stock)
The research was carried out by the University of Edinburgh and University College London. It was led by Professor Ruth Andrew, a personal chair of pharmaceutical endocrinology at Edinburgh.
'We found that commonly prescribed medications for prostate disease can increase risk of type 2 diabetes,' Professor Andrew said.
More than three million prescriptions of finasteride are issued every year by the NHS in England – and many more are bought privately.
In the US, about eight million a year take it for prostate issues and 1.2million for hair loss.
The 5-alpha-reductase inhibitors are often prescribed to treat benign prostatic hyperplasia (BPH), the medical term for an enlarged prostate.
This becomes more common with age, with an estimated prevalence of between eight and 60 per cent in men aged 90.
To determine the health effects of the drug, the researchers analysed the health records of 55,275 men in the UK who had been prescribed 5-alpha-reductase inhibitors for their BPH over 11 years.
Results - published in the British Medical Journal - revealed the drugs raise a man's risk of developing type 2 diabetes by around one-third.
Finasteride was originally developed to treat urinary problems in men, but during trials scientists found an unexpected side effect - hair growth.
In 1997, the FDA approved the steroid inhibitor as the first ever drug to treat male pattern baldness.
Taken once a day, the drug is mainly sold under the brand name Propecia.
Millions of American adults use the pills, which are proven to be 90 per cent effective.
It is unsure how many men in the UK use it as it is a prescription-only treatment that isn't available on the NHS.
But Asda are able to sell the drug without prescription as it will be available through a
