Rare brain disorder linked to obesity, says study

A ONCE-RARE brain disorder that can cause blindness is becoming increasingly common due to rising levels of obesity, a new study warned.

Mimicking the symptoms of a tumour, cases of idiopathic intracranial hypertension (IIH) – when pressure in the fluid surrounding the brain rises – are soaring.

With women of child-bearing age most at risk, it causes chronic, disabling headaches, vision problems and, in some rare cases, vision loss. Treatment is often weight loss.

Diagnosis of IIH each year rose six-fold between 2003 and 2017, with 12 out of 100,000 people living with the disorder, compared to 76 people in 2017.

In 2013, two out of every 100,000 people were diagnosed with the disorder, compared to eight people in every 100,000 in 2018.

Data from 35 million patients over 15 years in Wales found 1,765 people with IIH during that time, with 85 per cent women.

There were strong links for both men and women between body mass index (BMI) and risk of the disorder, according to the study. Female cases showed 180 with a high BMI while 13 had a BMI considered to be ideal.

For men, there were 21 cases among those with a high BMI compared to eight cases for those with an ideal BMI.

Researchers also found that, for women only, socioeconomic factors were linked to risk.

The women in the group with the fewest socioeconomic advantages had a 1.5 times greater risk of developing the disorder than women in the group with the most, even after adjusting for BMI.

Dr William Owen Pickrell, of Swansea University, said: “The considerable increase in idiopathic intracranial hypertension we found may be due to many factors but likely mostly due to rising obesity rates.

“What is more surprising from our research is that women who experience poverty or other socioeconomic disadvantages may also have an increased risk independent of obesity.”