Results from a Swedish study researching cardiovascular risk show that people with Down syndrome are at significantly increased risk of both ischemic and hemorrhagic stroke compared to those without the condition.
Risks of other cardiovascular events, such as heart attack, were no higher in people with the genetic condition than in the rest of the population, although in people under the age of 40 years, people with Down syndrome had a higher risk.
Current estimates suggest up to 600,000 people are living with Down syndrome in the United States. Caused by having either a partial or complete extra copy of chromosome 21, the extra genetic material causes variable intellectual disability and other health conditions, including congenital heart defects and increased risk for leukemia and Alzheimer’s disease in later life.
In the early 1980’s the average lifespan of people with Down syndrome was 25 years, but this has risen dramatically and is now almost 60 years.
“To date, the number of population-based studies on age-related comorbidities in large cohorts of Down syndrome individuals is limited,” wrote lead author Annie Pedersen, a researcher at the University of Gothenburg, and colleagues in the Journal of Internal Medicine.
“Clinical practice guidelines for this group are hampered by the lack of high-quality evidence, which limits the strength of recommendations and highlights the need for additional research within this area.”
To try and combat this lack of data, Pedersen and co-workers carried out a study of 5,155 individuals with Down syndrome (55% male, median age 35 years) and assessed risks for different cardiovascular outcomes compared with the overall population. Every person with the genetic condition was matched to several comparator individuals by sex, birth year, and county of birth.
The researchers found that individuals with Down syndrome had a 4.4-fold increased risk of ischemic stroke, and a 5.1-fold increased risk of hemorrhagic stroke compared with controls.
Notably, despite having a higher level of congenital heart defects, overall rates of acute myocardial infarction were slightly lower in people with Down syndrome than in the general population. Although when the analysis was limited to people under 40 years of age, rates of myocardial infarction were 3.5-fold higher in people with Down syndrome.
“These findings contradict the view that Down syndrome individuals are spared from cardiovascular outcomes due to the absence of atherosclerosis. Instead, our results indicate a different spectrum of cardiovascular risk factors in Down syndrome, which might have implications for screening measures as well as primary and secondary prevention strategies,” concluded the authors.
“These findings should inform future studies that aim to further investigate the pathophysiological mechanisms of cardiovascular diseases in Down syndrome.”
