Exercise Is Associated with Reduced Risk for Incident Dementia among Persons 65 Years of Age and Older

  1. Eric B. Larson, MD, MPH;
  2. Li Wang, MS;
  3. James D. Bowen, MD;
  4. Wayne C. McCormick, MD, MPH;
  5. Linda Teri, PhD;
  6. Paul Crane, MD, MPH; and
  7. Walter Kukull, PhD
  1. From the Center for Health Studies, Group Health Cooperative; University of Washington; and Health Services Research and Development Center of Excellence, VA Puget Sound Health Care System, Seattle, Washington.

    Abstract

    Background: Alzheimer disease and other dementing disorders are major sources of morbidity and mortality in aging societies. Proven strategies to delay onset or reduce risk for dementing disorders would be greatly beneficial.

    Objective: To determine whether regular exercise is associated with a reduced risk for dementia and Alzheimer disease.

    Design: Prospective cohort study.

    Setting: Group Health Cooperative, Seattle, Washington.

    Participants: 1740 persons older than age 65 years without cognitive impairment who scored above the 25th percentile on the Cognitive Ability Screening Instrument (CASI) in the Adult Changes in Thought study and who were followed biennially to identify incident dementia.

    Measurements: Baseline measurements, including exercise frequency, cognitive function, physical function, depression, health conditions, lifestyle characteristics, and other potential risk factors for dementia (for example, apolipoprotein E ε4); biennial assessment for dementia.

    Results: During a mean follow-up of 6.2 years (SD, 2.0), 158 participants developed dementia (107 developed Alzheimer disease). The incidence rate of dementia was 13.0 per 1000 person-years for participants who exercised 3 or more times per week compared with 19.7 per 1000 person-years for those who exercised fewer than 3 times per week. The age- and sex-adjusted hazard ratio of dementia was 0.62 (95% CI, 0.44 to 0.86; P = 0.004). The interaction between exercise and performance-based physical function was statistically significant (P = 0.013). The risk reduction associated with exercise was greater in those with lower performance levels. Similar results were observed in analyses restricted to participants with incident Alzheimer disease.

    Limitations: Exercise was measured by self-reported frequency. The study population had a relatively high proportion of regular exercisers at baseline.

    Conclusion: These results suggest that regular exercise is associated with a delay in onset of dementia and Alzheimer disease, further supporting its value for elderly persons.

    Article and Author Information

    • Grant Support: By the National Institute of Aging (grant AG06781).

    • Potential Financial Conflicts of Interest: Grants received: L. Teri (National Institutes of Health).

    • Requests for Single Reprints: Eric B. Larson, MD, MPH, Center for Health Studies, Group Health Cooperative, 1730 Minor Avenue, Suite 1600, Seattle, WA 98101-1448; e-mail, larson.e{at}ghc.org.

    • Current Author Addresses: Dr. Larson: Center for Health Studies, Group Health Cooperative, 1730 Minor Avenue, Suite 1600, Seattle, WA 98101-1448.

    • Ms. Wang: VA Puget Sound Health Care System, 1100 Olive Way, Seattle, WA 98101.

    • Dr. Bowen: Department of Neurology, University of Washington, 1959 NE Pacific, Seattle, WA 98195.

    • Dr. McCormick: Harborview Medical Center, 325 9th Avenue, Box 359755, Seattle, WA 91895.

    • Dr. Teri: University of Washington, 9709 3rd Avenue NE, Suite 507, Seattle, WA 91115.

    • Dr. Crane: University of Washington, 325 9th Avenue, Box 359780, Seattle, WA 91895.

    • Dr. Kukull: Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195.

    • Author Contributions: Conception and design: E.B. Larson, L. Wang, J.D. Bowen, L. Teri.

    • Analysis and interpretation of the data: E.B. Larson, L. Wang, J.D. Bowen, W.C. McCormick, L. Teri, P. Crane.

    • Drafting of the article: E.B. Larson, L. Wang, J.D. Bowen, W.C. McCormick.

    • Critical revision of the article for important intellectual content: J.D. Bowen, W.C. McCormick, L. Teri, P. Crane, W. Kukull.

    • Final approval of the article: E.B. Larson, J.D. Bowen, W.C. McCormick, L. Teri, P. Crane.

    • Provision of study materials or patients: E.B. Larson, J.D. Bowen, W.C. McCormick.

    • Statistical expertise: L. Wang, W.C. McCormick, P. Crane.

    • Obtaining of funding: E.B. Larson, L. Teri, W.A. Kukull.

    • Administrative, technical, or logistic support: E.B. Larson, L. Teri, P. Crane.

    • Collection and assembly of data: E.B. Larson.

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