New findings published in the medical journal of the American Academy of Neurology (AAN) reveal that rates of a brain pressure disorder known as idiopathic intracranial hypertension are rising, correlating with increasing levels of obesity.

Idiopathic intracranial hypertension occurs when the pressure in the skull around the brain increases in the absence of a tumor or excessive amounts of cerebrospinal fluid. (Idiopathic means of unknown cause.) The disorder can cause chronic, disabling headaches, vision problems and sometimes vision loss. Women of childbearing age are more likely to be diagnosed with it. Treatment for the illness usually involves weight loss, but in some cases, surgery is necessary. 

For the study, researchers identified 1,765 people in Wales with idiopathic intracranial hypertension between 2003 and 2017 and recorded each participant’s body mass index (BMI), a ratio of height to weight. (A total of 85% of the group were women 85%.) 

To each person with the disorder, scientists matched three others without it based on gender, age and socioeconomic status, which was determined by the regions where people lived. Participants were then split into five groups that ranged from those with the fewest socioeconomic advantages to those with the most. 

Results showed a sixfold increase in the number of cases of the disorder over the 15-year study period. In 2003, for every 100,000 people, 12 people were living with the disorder, compared with 76 people in 2017. 

Scientists noted that the number of people with idiopathic intracranial hypertension in Wales might be associated with an increase in obesity in the country. (Rates rose from 29% in 2003 to 40% in 2017.)

Despite the study’s focus on Wales, Pickrell believes the findings could have global relevance, as the world prevalence of obesity has nearly tripled since 1975. 

Researchers also found a significant link between BMI and an increased risk for the disorder among both men and women. For men, there were 21 cases per 100,000 among those with a high BMI compared with eight cases among those with an ideal BMI. Among women, there were 180 cases per 100,000 people for those with high BMI compared with 13 women with a BMI considered to be ideal. 

In addition, scientists observed that women’s socioeconomic status was linked to their risk of the brain pressure disorder, which was not the case for men. Results showed that women with the fewest socioeconomic advantages had a 1.5 greater risk of developing the disorder compared with those who enjoyed the most benefits. (Women in the two groups with the fewest socioeconomic advantages made up more than half of the study’s female participants.) 

“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 order,” said Pickrell.

For related coverage, read "CDC Finds Adult Obesity Is Rising in the U.S."