Idiopathic intracranial hypertension (IIH) may double the risk for cardiovascular disease in women, according to study results published in JAMA Neurology.
Although obesity is a known cardiovascular risk factor, there is no information regarding the risk for cardiovascular disease associated with diagnosis of IIH. As such, investigators sought to assess the cardiometabolic risk in this population, independent of body mass index (BMI). The primary outcome was a composite of any cardiovascular disease (heart failure, ischemic heart disease, or stroke/transient ischemic attack). Secondary outcomes included each of the cardiovascular outcomes separately: type 2 diabetes mellitus and hypertension.
The population-based matched controlled cohort study was based on data from between January 1990 and January 17, 2018, from The Health Improvement Network (THIN), a national database of electronic primary care records generalizable to the UK population. The cohort included 2760 women with IIH (9.2%; median age, 32.1 years; 62.6% were obese) and 27,125 women without IIH (90.8%; median age, 32.1 years; 60.9% were obese), matched for age and BMI.
Annual incidence of IIH in women more than tripled from 2.5 per 100,000 person-years in 2005 to 9.3 per 100,000 person-years in 2017, and was highest in the 20- to 29-year age group. The incidence of IIH increased with increasing BMI. Crude incidence rate of composite cardiovascular events was 5.31 per 1000 person-years among women with IIH compared with 2.47 per 1000 person-years among women without IIH (adjusted hazard ratio [aHR], 2.10; 95% CI, 1.61-2.74, P <.001).
All aHRs for individual cardiovascular disease outcomes indicated a statistically significant increased risk among patients with IIH compared with matched patients without IIH: heart failure (aHR, 1.97; 95% CI, 1.16-3.37; P =.01), ischemic heart disease (aHR, 1.94; 95% CI, 1.27-2.94; P =.002), and stroke/transient ischemic attack (aHR, 2.27; 95% CI, 1.61-3.21; P <.001). Furthermore, the crude incidence of type 2 diabetes mellitus (aHR, 1.30; 95% CI 1.07-1.57; P =.009) and hypertension (aHR, 1.55; 95% CI, 1.30-1.84; P <.001) was also increased in those with IIH compared with the control group.
The researchers acknowledged several limitations of the study, including the use of database data with potential biases, relatively short follow-up, missing information regarding physical activity, and possible surveillance bias from greater number of contacts between women with IIH and healthcare professionals.
“A step change in clinical practice to include assessment and management of cardiovascular risk in IIH is likely to be advantageous in efforts to improve long-term health outcomes for patients and warrants further evaluation,” concluded the researchers.
Adderley NJ, Subramanian A, Nirantharakumar K. Association between idiopathic intracranial hypertension and risk of cardiovascular diseases in women in the United Kingdom [published online July 8, 2019]. JAMA Neurol. doi:10.1001/jamaneurol.2019.1812.