Poor physical performance leads to dementia

Lower levels of physical performance are associated with an increased risk of dementia and Alzheimer's disease. Researchers from the Group Health Cooperative in Seattle, USA found that diminished physical function precedes the onset of cognitive impairment, which includes memory, perception, problem-solving, conceptualisation and attention deficits. Identifying the early signs of dementia could help predict disease progression and may permit more timely treatment to slow down these devastating illnesses. The researchers assessed the physical performance in 2,288 people who were 65 years of age or older. They 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. During the follow up, 319 subjects developed dementia, including 221 with Alzheimer's disease. 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, subjects with cognitive impairment, poor grip strength was predictive of dementia. The findings suggest that lower levels of physical performance were associated with an increased risk of dementia and Alzheimer's disease. It also suggests that poor physical function may precede the onset of dementia and Alzheimer's disease and regular physical activity may be associated with a delayed onset.