Early cardiovascular disease may speed up cognitive decline in middle age

Cardiovascular diseases (CVD) are a major cause of global mortality and disability. Although the CVD burden is declining in those aged over 50, current rates of CVD below this age have either remained steady or increased.

In high-income countries, lifestyle factors, such as obesity, lack of physical activity, and poor diet, are all increasing the incidence of CVD.

Studies have shown that cardiovascular risk factors may contribute to late-life cognitive decline and dementia but, until now, there has been little evidence that CVD might speed cognitive decline in middle age. 

Now, new research, part of the Coronary Artery Risk Development in Young Adults (CARDIA) study, has found that premature CVD — at or below the age of 60 — may affect brain health and increase cognitive decline in midlife.

The research appears in Neurology, the journal of the American Academy of Neurology. 

Long-term study

This prospective cohort study enrolled people aged between 18 and 30 years, and followed them for 30 years. Participants had follow-up examinations every 2–5 years during the study.

The participants were from four cities in the United States, just over half were female and just under half were Black. 

Dr. Sandra Narayanan, board-certified vascular neurologist and neurointerventional surgeon at Pacific Stroke & Neurovascular Center at Pacific Neuroscience Institute in Santa Monica, CA, who was not involved in the study, commented for Medical News Today: 

“The longitudinal, prospective study design over 30 years limits bias. The number and forms of cognitive assessments applied to this large cohort during this period also enabled a thorough evaluation of brain health in multiple domains such as executive functioning, processing speed, and verbal learning and memory.”

At the 30-year point, 3,146 participants, with a mean age of 55 years, underwent a range of cognitive assessments. In total, 147 (4.7%) had developed one or more premature CVD events, 126 of which were coronary heart disease or stroke. The mean age of the first CVD event was 48.4 years.

Those who had premature CVD were more likely to be male, older, Black, have had access to less education, have lower household income, and have more risk factors for CVD, such as poor diet and low levels of physical activity.

Wide-ranging cognitive assessments

Researchers tested participants in verbal fluency, global cognition, verbal memory, processing speed, and executive function.

They adjusted for demographics, education, literacy, household income, depressive symptoms, physical activity, diet, and APOE — a gene that is linked to an increased risk of dementia — when analyzing their findings.

In addition, they assessed 5-year cognitive decline in 2,722 people who underwent testing at both the 25- and 30-year points.

At the end of the study, 663 participants also underwent MRI brain scans to assess white matter hyperintensities (WMH), which are associated with cognitive impairment. The researchers also used diffusion tensor imaging to assess participants’ brain health.

Only a small proportion of those undergoing MRI scans had early CVD, as lead author Dr. Xiaqing Jiang, a postdoctoral scholar in the Department of Psychiatry and Behavioural Sciences at the University of California, San Francisco, told MNT.

“Among those with MRI, 16 participants had premature CVD. More people will develop premature CVD events as they age as most participants were still under 60,” she said.