Physical Activity and the Risk of Dementia in Oldest Old

Aleksandra Sumic, MPH

Oregon Health and Science University, Portland, Oregon, sumica@ohsu.edu .

Yvonne L. Michael, ScD

Oregon Health and Science University, Portland, Oregon

Nichole E. Carlson, PhD

Oregon Health and Science University, Portland, Oregon

Diane B. Howieson, PhD

Oregon Health and Science University, Portland, Oregon

Jeffrey A. Kaye, MD, PhD

Oregon Health and Science University, Portland, Oregon

Objective: This study evaluated the protective role of physical activity (PA) against cognitive impairment (CI) in the oldest old (age 85). Method: Prospective data on 66 optimally healthy, oldest old adults (mean age 88.5) were analyzed using survival analysis. Results: In all, 12 men and 11 women reported exercising > 4 hours per week, and 38 participants developed CI (mean onset age 93; mean follow-up 4.7 years). The effect of exercise was modified by gender. In more active women (> 4 hours/week), the risk of CI was reduced by 88% (95% confidence interval 0.03, 0.41) compared to those less active. Less active women had 2 times the incidence rate of CI compared to less active men and almost 5 times the rate compared to active women. Discussion: This study demonstrates the beneficial effects of exercise on healthy brain aging even in the oldest old and emphasizes the importance of increasing PA in older women.

Key Words: oldest old • physical activity • exercise • dementia • cognitive impairment