Early cardiac risks linked to worse cognitive function in middle age, says a new study, "Early Adult to Mid-Life Cardiovascular Risk Factors and Cognitive Function," published online March 31, 2014 in Circulation: Journal of the American Heart Association. The outcome of continued risk factors during the years from youth to middle age could be inflammation, oxidative stress, and damaged neurons. What you don't want to have happen is reducing blood supply to the brain, causing changes in brain structure and cognition because of the risk factors when those factors are modifiable.
Researchers from the University of California - San Francisco report that blood pressure, glucose and cholesterol in 18- to 30-year-olds predicts decline. Does the damage begin before middle age?
Young adults with such cardiac risk factors as high blood pressure and elevated glucose levels have significantly worse cognitive function in middle age, according to a new study by dementia researchers at UC San Francisco.
The findings, published in the journal Circulation: Journal of the American Heart Association, bolster the view that diseases like Alzheimer's develop over an individual's lifespan and may be set in motion early in life. And they offer hope that young adults may be able to lower their risk of developing dementia through diet and exercise, or even by taking medications.
The risk factors are modifiable
"These cardiovascular risk factors are all quite modifiable," said senior author Kristine Yaffe, MD, according to the March 31, 2014 news release, Early cardiac risks linked to worse cognitive function in middle age. Yaffe is a professor in the departments of Psychiatry, Neurology, and Epidemiology and Biostatistics at UCSF, who holds the Roy and Marie Scola Endowed Chair in Psychiatry.
"We already know that reducing these risk factors in midlife can decrease the risk of dementia in old age," continued Yaffe, according to the news release. Yaffe also is Chief of Geriatric Psychiatry and Director of the Memory Disorders Clinic at the San Francisco VA Medical Center. "If it turns out that the damage begins before middle age, we may need to expand our focus and work on reducing heart disease risks in earlier stages of life."
Participants studied were 18 to 30-year olds in the Coronary Artery Risk Development in Young Adults (CARDIA) study
The study, published March 31, 2014 in Circulation, examines data from more than 3,300 18- to 30-year-olds in the Coronary Artery Risk Development in Young Adults (CARDIA) study, which began enrolling thousands of participants nationwide in 1985 to understand how heart disease develops in black and white adults.
Cardiac risk factors were measured every two to five years for 25 years, at which point those in the study underwent tests to measure their executive function, cognitive processing speed and verbal memory. Blood pressure and blood glucose levels of the study's participants were measured throughout the study.
Those whose blood pressure and glucose exceeded recommended levels during the 25-year study performed worse on all three tests, while high cholesterol was associated only with poor verbal memory
The authors cited a number of mechanisms by which elevated blood pressure and glucose could diminish cognition in middle age, such as by reducing blood supply to the brain, causing changes in brain structure and increasing inflammation and oxidative stress, which can damage neurons.
The researchers were looking at whether risk factors appearing in young people would hinder cognitive function by the time the participants in the study reached middle age. The study's abstract explained that cumulative exposure to cardiovascular risk factors (CVRFs) from early to mid-adulthood, especially above recommended guidelines, was associated with worse cognition in mid-life. The meaning of this association and whether it warrants more aggressive treatment of cardiovascular risk factors (CVRFs) earlier in life requires further investigation.
Another possibility is that these risk factors may interfere with the clearance of amyloid proteins associated with Alzheimer's disease. But since cognitive function was not measured at the beginning of the study, the authors couldn't estimate the cognitive change caused by these risk factors.
Studies have linked mid- and late-life cardiovascular risk factors (CVRFs) to cognitive function, yet little is known about CVRF exposure in early adulthood and subsequent cognitive function
Most studies rely on single assessments of CVRFs which may not accurately reflect long-term exposure. In this new study, the researchers sought to determine the association between cumulative exposure to CVRFs from early to mid-adulthood and cognitive function at mid-life, the study's abstract observed.
Co-authors of the study are Eric Vittinghoff, PhD, and Mark J. Pletcher, MD, MPH, of UCSF; Tina Hoang, MSPH, of the Northern California Institute for Research and Education, San Francisco; Lenore Launer, PhD, of the National Institute on Aging; Rachel Whitmer, PhD, and Stephen Sidney, MD, of Kaiser Permanente of Northern California, Oakland; and Laura H. Coker, PhD, of Wake Forest School of Medicine, Winston-Salem, NC.