A recent study is raising concerns about the increasing rates of a specific type of stroke called subarachnoid hemorrhage. The research reveals that older individuals and men are experiencing a rise in these strokes in recent years. Notably, Black people are disproportionately affected by this type of stroke compared to individuals of other races and ethnicities.
Subarachnoid hemorrhage occurs when there is bleeding in the space between the brain and its protective covering, usually due to a burst blood vessel. It can be caused by an aneurysm rupture, high blood pressure, or trauma. However, the study focused only on cases unrelated to trauma, which account for 5% to 10% of all strokes in the United States.
“Not only did we find an increase in these strokes over recent years, we also found the incidence was disproportionately higher and increasing in Black people while rates did not increase in people of other races and ethnicities,” says Dr. Fadar Oliver Otite, who led the research team at SUNY Upstate Medical University in Syracuse, New York.
The research team examined state hospitalization databases for New York and Florida, identifying 39,475 people hospitalized for non-traumatic subarachnoid hemorrhage between 2007 and 2017. By analyzing Census data, they calculated the annual rates of this type of stroke for various groups.
Over the ten-year study period, the average incidence of subarachnoid hemorrhage for all participants was 11 cases per 100,000 people. The rates were higher in women, with 13 cases per 100,000 people, and lower in men, with 10 cases. Moreover, the incidence increased with age, showing an average of four cases per 100,000 people for middle-aged men and 22 cases for men aged 65 and older.
The study revealed an overall increase in incidence over time, with a rise of 0.7% per year on average. Notably, the increase was more prominent in middle-aged men (1.1%), older men (2.3%), and older women (0.7%), while young women saw a slight decline of 0.7%.
When considering race and ethnicity, the researchers found that Black individuals experienced a higher incidence of this type of stroke, with an average of 15 cases per 100,000 people compared to 10 cases in non-Hispanic white individuals. Moreover, the incidence in Black people increased by 1.8% per year, while rates for Hispanic, Asian, and non-Hispanic white individuals remained stable over time.
Dr. Otite emphasizes that addressing the racial disparities in stroke incidence requires multifaceted interventions targeting stroke risk factors and socioeconomic inequity. Previous studies have shown that Black individuals develop high blood pressure at a younger age and are more likely to have uncontrolled high blood pressure compared to non-Hispanic white individuals. Efforts to control blood pressure may play a crucial role in reducing stroke rates in this population.
The study’s limitations included the inability to differentiate between strokes caused by aneurysms and those not caused by aneurysms, which could have provided further insights into the condition.
As the medical community seeks to tackle this growing concern, understanding the factors contributing to the increased rates of subarachnoid hemorrhage among older adults and Black individuals will be essential for developing effective preventive measures and ensuring better health outcomes for all.
The study is published in the medical journal Neurology.