Exercise Prevents Dementia in Some Seniors

Older people who are living independently but have signs of cerebral damage may lower their risk of having progressive cognitive impairment or dementia if they remain physically active, researchers found.

Even after adjustment for white matter changes seen on MRI and history of stroke, those who met criteria for physical activity had significantly lower risks of developing any cognitive impairment, any dementia, and vascular dementia over a 3-year period, according to Ana Verdelho, MD, of the University of Lisbon in Portugal, and colleagues.

The relationship between physical activity and vascular dementia remained significant after further adjustment for baseline cognitive function (HR 0.49, 95% CI 0.26 to 0.94), the researchers reported online in Stroke: Journal of the American Heart Association.

“Our data support the conviction that older subjects with vascular risk factors and evidence for vascular cerebral damage benefit from regular physical activity,” Verdelho and colleagues wrote. “We think that [the] relation between physical activity and cognitive impairment should be further studied by interventional studies.”

Previous analyses have identified associations between physical activity and lower risks of cognitive decline and progression to dementia, with possible explanations including mental and social stimulation from exercise, improved cerebral blood flow, reduced vascular risk factors, decreased stress hormone levels, stimulation of brain plasticity, enhanced endothelial function, and decreased progression of intima-media thickness.

Verdelho and colleagues turned to the European LADIS (Leukoaraiosis and Disability) study to explore the issue in nondisabled individuals ages 65 to 84 who were living on their own, presented with minor neurological, cognitive, mood, or motor complaints that did not affect daily activities, and who had white matter changes seen on MRI.

The participants were evaluated at baseline and annually for 3 years. At each assessment, they underwent a battery of neuropsychological tests. MRI was performed at baseline and at the end of the study to assess the severity of the white matter changes.

The study included 638 people. The average age was 74.1 and 55% were female.

At baseline, 64% of the participants were considered physically active, defined as performing at least 30 minutes of activity at least 3 days a week.

The initial MRI revealed a severity of white matter changes that was mild in 44%, moderate in 31%, and severe in 25%.

At the end of follow-up, 90 patients had dementia, including 54 with vascular dementia, 34 with Alzheimer’s disease with a vascular component, and two with frontotemporal dementia. Another 147 had cognitive impairment that was not dementia.

After adjustment for age, education, the severity of white matter changes, medial temporal atrophy, previous and incident stroke, and diabetes, being physically active was associated with significantly lower risks of the following outcomes:

• Any cognitive impairment, including dementia (HR 0.64, 95% CI 0.48 to 0.85)
• Any dementia (HR 0.61, 95% CI 0.38 to 0.98)
• Vascular dementia (HR 0.42, 95% CI 0.22 to 0.80)

Physical activity was not, however, related to Alzheimer’s disease risk.

After further adjustment for baseline cognitive function, the results remained significant for any cognitive impairment and vascular dementia, but not for any dementia.

The authors said that the main limitation of the study was related to the selection of the participants. The study included those who had minor complaints and, thus, probably catches nondisabled patients with white matter changes when they are first seeking medical attention.

Primary source: Stroke: Journal of the American Heart Association
Source reference:
Verdelho A, et al “Physical activity prevents progression for cognitive impairment and vascular dementia: results from the LADIS (Leukoaraiosis and Disability) study” Stroke 2012; DOI: 10.1161/STROKEAHA.112.661793.

By Todd Neale, Senior Staff Writer, MedPage Today
Published: November 01, 2012
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and Dorothy Caputo, MA, BSN, RN, Nurse Planner