Poor physical performance was linked with an increased risk of dementia in a study of individuals age 90 and older who were followed for an average of 2.6 years. After controlling for various factors, poor standing balance had the strongest association with dementia, followed by poor performance in a four-meter walk test and a handgrip test. The study findings were published online ahead of print July 5 in the Journal of the American Geriatrics Society.
“The oldest old, people aged 90 and older, represent the fastest-growing segment of society with the highest rates of dementia; however, many of the traditional risk factors of dementia lose or change their effect in this age group. Therefore, it is crucial that we identify age-specific risk and protective factors for late-age dementia,” said lead author Szofia S. Bullain, MD, an Assistant Professor of Neurology at the University of California, Irvine. “The fact that we were able to detect impairment in physical performance two to three years before the onset of dementia suggests that poor physical performance may be a risk factor for, or an early sign of, developing late-age dementia.”
Dr. Bullain and colleagues conducted a population-based, longitudinal study to examine the relationship between physical performance and dementia in individuals age 90 and older without dementia. They enrolled 176 men and 402 women without dementia from the 90+ Study. Among the total cohort of 578, the mean age was 93.3. At baseline, 54% of the participants were cognitively normal, and 46% had cognitive impairment, but no dementia.
Szofia S. Bullain, MD
Physical performance measures included a four-meter walk, five chair stands, handgrip, and standing balance. Measures were scored from zero (unable to perform) to four (best performance). The outcome was dementia, diagnosed according to DSM-IV criteria. Hazard ratios (HRs) for dementia in relation to baseline physical performance were estimated using Cox regression after adjustment for potential confounders.
Poor physical performance in most measures was associated with greater risk of incident dementia over a mean follow-up of 2.6 years (range, seven months to nine years). After controlling for potential confounders, standing balance had the strongest association with incident dementia (HR, 1.9 to 2.5), followed by four-meter walk (HR, 1.1 to 1.8) and handgrip (HR, 1.0 to 2.0). The association with five chair stands was not significant.
The researchers next plan to examine the underlying pathologic processes, which may provide clues to new preventive and treatment strategies for late-age dementia.
—Glenn S. Williams