Heart Function Tied to Brain Function
Heart Function Tied to Brain Function:- Lower cardiac output has been tied to poorer cerebral blood flow (CBF) in the temporal lobes of older adults without heart failure, a finding that adds to a growing body of research linking heart health to brain health.
The associations were statistically independent of key covariates, including vascular risk factors, cardiovascular disease (CVD), atrial fibrillation, and atrophy.
The study is part of a growing body of research demonstrating the strong connection between heart and brain health.
“Researchers know a lot about preventing and managing most forms of heart disease, but not how to prevent Alzheimer’s disease and dementia,” Angela Jefferson, PhD, professor of neurology, and director of the Vanderbilt Memory & Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, Tennessee, told Medscape Medical News
“This research, which links heart function to brain function, is especially important because it suggests that we can use knowledge about managing heart health to treat risk factors for memory loss in older adults, perhaps before memory loss or other cognitive symptoms develop.”
The study was published online November 8 in Neurology.
The brain accounts for only 2% of total body weight but receives 12% of cardiac output. Prior research shows patients with severe heart failure have poor cardiac function and lower blood flow in the brain.
However, it’s believed that blood flow to the brain is preserved in those without heart failure because of a complex autoregulatory control system that maintains constant blood supply to the brain in both resting and acute conditions.
“Our results are among the first evidence in aging adults who don’t have heart failure that these complex regulation processes may be vulnerable and less effective as we get older,” said Dr Jefferson.
The analysis included 314 persons (mean age, 73 years; 59% men) who participate in the Vanderbilt Memory & Aging Project, a longitudinal study investigating vascular health and brain aging. Study participants did not have heart failure, clinical dementia, or stroke.
Of the 314 participants, 39% had mild cognitive impairment (MCI), which increases the risk of developing dementia or Alzheimer’s disease, while the remaining participants had normal cognitive function.
Researchers measured the cardiac index — the amount of blood flowing out of the heart, adjusted for body size — by using echocardiography. They measured blood flow in the brain with MRI.
They adjusted for age; education; race/ethnicity; Framingham stroke risk profile score, which includes systolic blood pressure, antihypertensive medication use, diabetes mellitus, smoking status, left ventricular hypertrophy, CVD, and atrial fibrillation; APOE ε4 allele status; cognitive diagnosis; and regional tissue volume.