A brain pressure disorder linked to obesity and deprivation which causes severely disabling headaches as well as vision loss has risen six-fold in 15 years.
Idiopathic intracranial hypertension (IIH) especially affects women. The new study by Swansea University researchers, published in Neurology, found rates of emergency hospital admissions in Wales for people with the disorder were five times higher than for those without.
The research team, from Swansea University Medical School, used anonymised health records of Welsh patients held in the SAIL databank, a national healthcare database managed by the University. They analysed 35 million patient years of data from 2003 to 2017. They identified 1,765 people with IIH during that time, 85% of whom were women.
Links between body mass index and risk of the disorder
They recorded the body mass index of people in the sample and estimated their relative deprivation using a standard national scoring system. For each person with IIH, they compared three people with a comparable profile who did not have the condition.
They found a six-fold increase in the number of cases of the disorder over the course of the study - from 12 cases per 100,000 in 2003 to 76 cases in 2017.
Rates of emergency hospital admissions were also five times higher in people with IIH, compared to others - 9% of people with IIH require brain surgery to try and preserve vision.
There were strong links for both men and women between body mass index and risk of the disorder. Obesity rates in Wales over the same period rose from 29% of the population to 40%. In addition, women in the most deprived areas had 1.5 times greater risk of developing the disorder than women in the least deprived areas.
Dr Owen Pickrell of Swansea University Medical School, who led the study, 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."
More research is needed to determine which socioeconomic factors such as diet, pollution, smoking or stress may play a role in increasing a woman's risk of developing this disorder.