According to new research published today (November 3, 2021) in the Journal of the American Heart Association, an open-access journal of the American Heart Association, insomnia may be a risk factor for a brain bleed from a ruptured aneurysm, alongside the more well-known risk factors of smoking and high blood pressure.
Intracranial aneurysms are unruptured blood artery abnormalities in the brain that affect more than 3% of adults globally, with the majority of them never rupturing.
A subarachnoid hemorrhage (SAH), commonly known as a brain bleed, occurs when about 2.5 percent of intracranial aneurysms rupture. When a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull, it is known as a SAH.
“Ruptured aneurysms are highly fatal. It is, therefore, extremely important to identify modifiable risk factors that can help prevent aneurysms from rupturing,” said study author Susanna C. Larsson, Ph.D., associate professor in the unit of cardiovascular and nutritional epidemiology at the Karolinska Institutet in Stockholm, Sweden, and the unit of medical epidemiology at Uppsala University in Uppsala, Sweden.
The association between insomnia and intracranial aneurysm has not been reported previously, and these findings warrant confirmation in future studies. Our research supports the thinking that risk factors that people can change or manage may impact brain aneurysms and hemorrhage risk. Once confirmed, future studies should examine ways to incorporate this knowledge into prevention programs and therapies.
Susanna C. Larsson
The researchers wanted to see if there were any links between certain parameters and cerebral aneurysms and/or aneurysm rupture. They looked at well-known risk factors like smoking and high blood pressure, as well as the relationship between aneurysms and coffee intake, sleep, physical activity, BMI, blood glucose levels, type 2 diabetes, blood pressure, cholesterol, chronic inflammation, and renal function.
Genetic correlations to lifestyle and cardiometabolic risk variables were assessed using data from multiple genome-wide association studies. The International Stroke Genetics Consortium used genetic data from a meta-analysis to identify over 6,300 cases of intracranial aneurysm and about 4,200 cases of aneurysmal subarachnoid hemorrhage.
To establish genetic propensity for aneurysms, researchers compared cases of intracranial aneurysm and subarachnoid hemorrhage to nearly 59,500 controls. According to the analysis:
- A 24% greater incidence of intracranial aneurysm and aneurysmal subarachnoid hemorrhage was linked to a genetic tendency for sleeplessness.
- The risk for intracranial aneurysm was about three times higher for smokers vs. non-smokers.
- For every 10 mm Hg increase in diastolic blood pressure (the bottom number in a blood pressure reading), the chance of intracranial aneurysm increased approximately thrice.
- Intracranial aneurysm and aneurysmal subarachnoid hemorrhage were not associated with high triglyceride levels or a high BMI.
“The association between insomnia and intracranial aneurysm has not been reported previously, and these findings warrant confirmation in future studies,” Larsson said. “Our research supports the thinking that risk factors that people can change or manage may impact brain aneurysms and hemorrhage risk. Once confirmed, future studies should examine ways to incorporate this knowledge into prevention programs and therapies.”
Insufficient and poor-quality sleep, as well as sleep disorders, are connected to a higher risk of high blood pressure, according to a 2016 American Heart Association scientific statement, Sleep Duration and Quality: Impact on Lifestyle Behaviors and Cardiometabolic Health. Treatment of patients with sleep disturbances may provide clinical advantages, particularly for blood pressure, according to the statement summary.
One of the study’s weaknesses was that there was insufficient data to properly examine some of the risk factors. Furthermore, because the study only included adults of European descent, the findings may not be applicable to people of various racial and ethnic backgrounds.
Co-authors are Ville Karhunen, Ph.D.; Mark K. Bakker, M.Sc.; Ynte M. Ruigrok, Ph.D.; and Dipender Gill, Ph.D. The study was funded by the Swedish Research Council for Health, Working Life and Welfare funded the study.
