Poor physical performance may precede dementia

Poor physical performance is associated with an increased risk of dementia and Alzheimer's disease among individuals 65 years of age or older, according to a new report. The findings suggest that diminished physical function precedes the onset of cognitive impairment.

Identifying the early signs of dementia could help predict disease progression and may permit more timely treatment to slow down these "devastating" illnesses, Dr. Eric B. Larson, from the Group Health Cooperative in Seattle, and colleagues report in the Annals of Internal Medicine.

The researchers assessed physical performance in 2,288 subjects and then monitored them from the mid-1990s through October 2003 for the development of dementia and Alzheimer's disease. Four tests were used to measure physical performance that focused on walking, chair-to-stand time, standing balance, and grip strength.

A total of 319 subjects developed dementia during follow-up, including 221 with Alzheimer's disease, the researchers report. The rate of dementia was significantly lower in individuals with the highest physical function scores than in those with the lowest scores.

For each 1-point drop in the physical function score, the risk of dementia and Alzheimer's disease rose by 8 percent and 6 percent, respectively. In addition, the Cognitive Ability Screening Instrument scores fell by 0.11 point per year with each 1-point reduction in physical function score.

In subjects without apparent cognitive impairment, those who developed a slower walking pace and poor balance appeared to have an increased risk of dementia. In contrast, in subjects who developed possible cognitive impairment, poor grip strength was predictive of dementia.

"These findings suggest that gait slowing and poor balance might relate to dementia and may occur during an earlier stage before cognitive impairment is apparent, and that poor handgrip might relate to dementia during a later stage when cognitive impairment has occurred," the authors conclude.

SOURCE: Archives of Internal Medicine, May 22, 2006.