Greater engagement in physical activity and lower vascular risk appeared to have protective effects on delaying the progression of Alzheimer’s disease, according to data presented at the Alzheimer’s Association International Conference and published in JAMA Neurology.
“Because there are no disease-modifying drugs for Alzheimer’s disease, it is important to find potentially modifiable risk factors that may delay the progression of the disease,” Jennifer S. Rabin, PhD, from the department of psychiatry, Massachusetts General Hospital, Harvard Medical School, told Healio Psychiatry.
Although prior research has shown the potential for physical activity in maintaining brain health and cognition in aging populations, most studies have not assessed the beta-amyloid burden, Rabin and colleagues wrote. In their longitudinal observational study, researchers evaluated whether physical activity moderated the link between beta-amyloid burden and longitudinal cognitive decline and neurodegeneration in clinically normal individuals. They also examined whether these connections were independent of vascular risk.
The investigators examined participants’ baseline beta-amyloid positron emission tomography data, cognition (using the Preclinical Alzheimer Cognitive Composite) each year, neurodegeneration (using structural MRI with a focus on total gray matter volume and regional cortical thickness) and physical activity (using a pedometer recording mean steps per day).
The study included 182 participants (56.6% female; mean age, 73.4 years).
Physical activity and lowering vascular risk offered protection against cognitive decline and brain volume loss, according to the study.
The results showed a significant interaction of physical activity with beta-amyloid burden in models examining Preclinical Alzheimer Cognitive Composite (PACC) decline and volume loss, which indicated that greater physical activity was linked to slower beta-amyloid–related cognitive decline (beta = 0.03; 95% CI, 0.02-0.05) and gray matter volume loss (beta = 482.07; 95% CI, 189.4-774.74). Also, these associations remained the same after adjusting for vascular risk, according to the results.
“The findings from our study suggest that even modest levels of physical activity (around 8,900 steps per day) may be protective against cognitive decline and brain volume loss in individuals showing very early brain changes indicative of Alzheimer’s disease,” Rabin said. “Another interesting finding was that these effects remained over and above vascular risk factors, and that lowering vascular risk offered additional protection against cognitive decline and brain volume loss in these individuals.”
The researchers found that lower vascular risk was independently tied to slower amyloid-beta–related PACC decline (beta = –0.04; 95% CI, –0.06 to –0.02) and volume loss (beta = –483.41; 95% CI, –855.63 to –111.2) in these models.
“These findings suggest that there are steps we can take to reduce the risk of developing Alzheimer's disease dementia,” Rabin told Healio Psychiatry. – by Savannah Demko
Disclosure: Rabin report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.