Could declining muscle function be a sign of dementia?

Edith Cowan University suggests that declining muscle function may indicate a higher risk of late-life dementia

Age-related decline in muscle strength and function can make simple tasks like getting up, walking, and sitting down difficult, but could it also be a sign of dementia?

New research from Edith Cowan University suggests that this could be the case.

In fact, declining muscle function may indicate a higher risk of late-life dementia.

Conducted by ECU’s Nutrition & Health Innovation Research Institute and Centre for Precision Health in collaboration with the University of Western Australia, the study examines more than 1,000 women with an average age of 75 to investigate the relationship between muscle function and dementia.

The timed-up-and-go TUG test explained

Using the strength and timed-up-and-go (TUG) test, in combination with grip strength, the researchers monitored any performance loss over five years.

The Timed Up and Go test, or the TUG test, is a simple evaluative test that measures functional mobility. The TUG test measures how long it takes to stand up, walk a distance of 10 feet, turn, walk back, and sit down again.

Typically used in physical therapy, the TUG test provides insight into how safely a person can move around and maintain balance while walking. Healthcare providers may also use the test to estimate a patient’s fall risk.

17% of women had a dementia event in the next 15 years

Almost 17% of the women involved in the study had a dementia event over the next 15 years.

Lower grip strength and slower TUG were identified as significant risk factors, independent of genetic risk and lifestyle factors such as smoking, alcohol intake, and physical activity levels.

Weaker grip strength doubles the chances of late-life dementia

It may sound shocking, but results showed that women with weaker grip strength were more than twice as likely to experience late-life dementia than those with stronger grips.

Furthermore, women with slower TUG test results were also linked with a greater risk of dementia.

In combination, after five years, this decline in both grip strength and TUG speed was associated with a higher risk of dementia.

Those who experienced the biggest decline in performance had approximately 2 and 2.5 times greater likelihood, respectively, of having a dementia event compared to those with the smallest decline.

The biggest drop in TUG performance was associated with over four times greater likelihood of dementia-related death in women.

Grip strength can indicate other issues

According to senior researcher Dr Marc Sim, grip strength may indicate brain health due to the close relationship between cognitive and motor decline. This can be easily measured using a handheld device called a dynamometer.

“Possibly due to a range of underlying similarities, grip strength may also present as a surrogate measure of cardiovascular disease, inflammation and frailty, which are known risk factors for dementia,” Dr Sim adds.

Declining muscle function helps identify dementia risk earlier

Dr Sim explains how studies on declining muscle function in older women could help health professionals to identify dementia risk in patients earlier.

‘Both grip strength and TUG tests aren’t commonly performed in clinical practice’

He explains: “Both grip strength and TUG tests aren’t commonly performed in clinical practice, but both are inexpensive and simple screening tools.

“Incorporating muscle function tests as part of dementia screening could be useful to identify high-risk individuals, who might then benefit from primary prevention programs aimed at preventing the onset of the condition such as a healthy diet and a physically active lifestyle.

“The exciting findings were that decline in these measures was associated with substantially higher risk, suggesting that if we can halt this decline, we may be able to prevent late-life dementias. However, further research is needed in this area.”

Centre for Precision Health Director Professor Simon Laws concludes, “We are now starting to see a number of simple yet indicative screening assessments that could be combined with other biological and clinical measures to provide a holistic risk-profile for individuals presenting to their GP with, for example, memory concerns.”