Excess hormones may cause condition leading to blindness in women: Study

LONDON

Increased levels of hormones including testosterone could cause a brain condition that may lead to blindness in women, according to a research.

Scientists at the University of Birmingham carried out the research which explores the role of hormones known as androgens in the way Idiopathic Intracranial Hypertension (IIH) develops.

The IIH is caused by high pressure in the brain with consequences from blindness to incapacitating daily long-term headaches.

IIH was originally identified over 100 years ago yet the cause of the condition has remained unknown, although there has been much speculation about why more than 95 per cent of total incidence is in women with obesity.

"For over 100 years the cause of IIH has been unknown. These findings mark a key step forward; for the first time we have found a pattern of androgen dysregulation that is unique to IIH and potentially a driver of abnormal brain pressure in people with the condition," said corresponding and senior author of the study Alex Sinclair.

"Taken together this provides the first evidence that IIH may be a manifestation of female androgen excess," said Sinclair, scientist at the varsity.

Once regarded as rare, incidence of IIH is now rising dramatically in line with the global rise in obesity and there has been a 150 per cent rise in incidence in last 10 years. Currently there are very limited treatment options.

The researchers examined the levels of androgens in blood and urine, as well as in brain fluid known as cerebrospinal fluid (CSF), in 55 women with IIH aged 18 to 45.

They then compared the results with the levels observed in women with obesity of the same age and body mass index (BMI), as well as a cohort of women with polycystic ovary syndrome (PCOS).

PCOS is a common condition and is classically associated with increased levels of specific types of androgens, which can cause excess hair and irregular periods, the varsity said in a statement on Thursday.

The researchers found that IIH patients had a very different profile of raised levels of androgens compared to women of a similar age with obesity and women with PCOS.

Most notable were the high levels of the androgen 'testosterone' found in the blood in IIH women.

Crucially, levels of androgens were uniquely increased in the brain fluid (CSF) of women with IIH.

When the researchers, analysed human choroidal plexus tissue, which is the site in the brain where CSF is produced, they confirmed that androgens could increase the rate of CSF secretion, a potential driver for increased brain pressure.

"These findings, for the first time, implicate androgens as a potential cause of IIH," said lead author Michael O'Reilly, Hoffenberg Clinician Scientist in Endocrinology and Human Metabolism at the University of Birmingham.

"These findings mark a significant step forward in a previously poorly understood disabling condition. Understanding the cause of a disease is a vital step to ultimately refine treatments which improved patient care and outcomes," said professor Wiebke Arlt, Director at the varsity's Institute of Metabolism and Systems Research. — PTI