Alzheimer’s disease is characterized by problems with memory, learning and thinking. It is also linked to other problems like impaired gait and decreased grip strength. According to a new study from a team at Rush University Medical Center, Chicago, there is a link between Alzheimer’s disease and muscle weakness.

They studied 970 older adults of average age 80 years who did not have Alzheimer’s disease at the start of the study. Each underwent 21 different cognitive tests and also had their muscle strength assessed by testing 11 different muscle groups. During an average follow up time of 3.6 years, each participant had another evaluation and the researchers recorded who developed Alzheimer’s disease during this time.

Over the study period, 138 participants – 14.2% of the total – developed Alzheimer’s disease. Muscle strength scores ranged from -1.6 to +3.3 units. For each one unit increase at the beginning of the study, the participants had a 43% decrease in the risk of developing Alzheimer’s disease during the follow-up. Those with the highest muscle strength had a 61% reduced risk of Alzheimer’s disease compared to those with the lowest muscle strength. Individuals who had the highest muscle strength also proved to have the lowest rate of cognitive decline. It is not clear what underlies the link between muscle weakness and Alzheimer’s disease. It may be some common factor that produces both conditions. Or it could be that changes in the brain preceding Alzheimer’s disease result in muscle weakness. Whatever the reason, muscle weakness might be an indicator that the patient needs a cognitive assessment to check for risk of Alzheimer’s disease.

Source:

Boyle PA et al Association of muscle strength with the risk of Alzheimer’s disease and the rate of cognitive decline in community-dwelling older persons Archives of Neurology November 2009;66:1339-1344