WEDNESDAY, July 17, 2019 (HealthDay News) -- Greater physical activity and lower vascular risk are associated with slower β-amyloid (Aβ)-related cognitive decline in clinically normal older adults, according to a study published online July 16 in JAMA Neurology to coincide with the annual Alzheimer's Association International Conference, held from July 14 to 18 in Los Angeles.
Jennifer S. Rabin, Ph.D., from Massachusetts General Hospital in Boston, and colleagues conducted a longitudinal observational study involving clinically normal participants to examine whether physical activity moderates the correlation of Aβ burden with longitudinal cognitive decline and neurodegeneration. Data were included for 182 participants. Physical activity was quantified using a pedometer as mean steps per day. Cognition was measured annually with the Preclinical Alzheimer Cognitive Composite (PACC) during a median follow-up of six years, while neurodegeneration was assessed with a focus on total gray matter volume and regional cortical thickness.
The researchers observed a significant interaction of physical activity with Aβ burden in models examining PACC decline and volume loss, such that greater physical activity correlated with slower Aβ-related cognitive decline (β, 0.03) and volume loss (β, 482.07). These associations were not altered with adjustment for vascular risk. Lower vascular risk was independently associated with slower Aβ-related PACC decline and volume loss in these models (β, −0.04 and −483.41, respectively).
"These findings support interventions that target both physical activity and management of vascular risk factors as a means of delaying cognitive decline and neurodegeneration in preclinical Alzheimer disease," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.