Swedish researchers have discovered that individuals with Down syndrome face substantially higher risks of cardiovascular events as they age, particularly strokes, according to a comprehensive study published May 7 in the Journal of Internal Medicine.
The research team, led by Annie Pedersen, Ph.D., from the Institute of Biomedicine at the University of Gothenburg, analyzed data from Swedish national registries to compare cardiovascular outcomes between 5,155 individuals with Down syndrome born between 1946 and 2000 and matched controls from the general population.
Significantly Elevated Stroke Risk
The findings revealed striking disparities in cardiovascular risk profiles. Individuals with Down syndrome demonstrated a 4.41 times higher risk of ischemic stroke (caused by blood clots) and a 5.14 times higher risk of hemorrhagic stroke (caused by brain bleeds) compared to the general population.
"Our results show that individuals with Down syndrome are at increased risk of some age-related cardiovascular outcomes, and indicate, in line with results from previous studies, that their cardiovascular risk factor profile differs from the general population," explained Pedersen.
The risk disparities became even more pronounced when examining specific subgroups. Down syndrome patients with atherosclerotic risk factors faced a staggering 12.67 times higher risk of ischemic stroke compared to controls without these risk factors. Similarly, those with embolic risk factors had a 10.35 times higher risk.
Age-Dependent Heart Attack Risk
While the overall risk of acute myocardial infarction (heart attack) was similar between groups, researchers identified an important age-related pattern. Younger individuals with Down syndrome—those under 40 years—showed an increased heart attack risk compared to age-matched controls.
This finding is particularly significant as the life expectancy for people with Down syndrome has increased dramatically in recent decades, rising from an average of 25 years in the early 1980s to approximately 60 years in 2020.
Different Pathophysiological Mechanisms
The researchers suggest that the increased risk of blood-clot-related strokes in Down syndrome patients likely stems from different underlying mechanisms than in the general population. Rather than being primarily driven by atherosclerosis (artery narrowing), the elevated risk appears more closely associated with congenital heart disease and diabetes.
For hemorrhagic strokes, the researchers hypothesize that lifestyle factors common in Down syndrome—including obesity, high cholesterol, and reduced physical activity—may contribute to the heightened risk.
Implications for Clinical Care
These findings have significant implications for healthcare providers managing aging Down syndrome patients. The study authors emphasize the need for tailored approaches to cardiovascular risk management in this population.
"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," the researchers wrote.
The study highlights the importance of developing specialized clinical guidelines that address the unique cardiovascular risk profile of individuals with Down syndrome. As this population continues to live longer, understanding and mitigating these specific risks becomes increasingly crucial.
"These findings should inform future studies that aim to further investigate the pathophysiological mechanisms of cardiovascular diseases in Down syndrome, as well as health care systems developing guidelines fitted for the unique needs of the Down syndrome population," the authors concluded.
The research underscores the evolving understanding of Down syndrome as not just a developmental condition but one with significant implications for age-related health outcomes, particularly cardiovascular health.
