By Stephen Beech via SWNS
Muscle loss increases the risk of dementia, warns new research.
Any decrease in the temporalis muscle – which is located in the head – may be a warning sign of Alzheimer’s disease, according to American scientists.
But they say that exercise, resistance training and nutritional support for older people may help prevent the onset of the debilitating condition.
The research team explained that skeletal muscles make up about one-third of a person’s total body mass.
Muscles are connected to the bones and allow for a wide range of movements.
But as people grow older, they begin to lose skeletal muscle mass.
Because age-related skeletal muscle loss is often seen in older adults with Alzheimer’s disease dementia, the research team aimed to examine whether temporalis muscle loss – a measure of skeletal muscle loss – is associated with an increased risk of Alzheimer’s dementia in older adults.
The temporalis muscle is used for moving the lower jaw.
Previous studies have shown that temporalis muscle thickness and area can be an indicator of muscle loss throughout the body.
Study lead author Dr. Kamyar Moradi, of Johns Hopkins University School of Medicine in Baltimore, said: “Measuring temporalis muscle size as a potential indicator for generalized skeletal muscle status offers an opportunity for skeletal muscle quantification without additional cost or burden in older adults who already have brain MRIs for any neurological condition, such as mild dementia.
“This is the first longitudinal study to demonstrate that skeletal muscle loss may contribute to the development of dementia.”
Dr. Moradi used brain MRI exams to quantify skeletal muscle loss in 621 participants, with an average of 77, who did not dementia.
The researchers manually segmented the bilateral temporalis muscle on MRI images and calculated the sum cross-sectional area (CSA) of those muscles.
Participants were categorized into two distinct groups: large CSA (131 participants) and small CSA (488 participants).
Based on their analysis, a smaller temporalis CSA was associated with a higher incidence risk of dementia.
A smaller temporalis CSA was also associated with a greater decrease in memory composite score, functional activity questionnaire score and structural brain volumes over the average follow-up period of 5.8 years.
Study co-senior author Dr. Marilyn Albert said: “We found that older adults with smaller skeletal muscles are about 60% more likely to develop dementia when adjusted for other known risk factors.”
But she said early detection through readily available brain MRI could enable “timely interventions” to address skeletal muscle loss – such as physical activity, resistance training and nutritional support.
Study co-senior author Dr. Shadpour Demehri added: “These interventions may help prevent or slow down muscle loss and subsequently reduce the risk of cognitive decline and dementia.”
The findings were presented at the annual meeting of the Radiological Society of North America (RSNA) in Chicago.
