PNI Study Links Muscular Strength and Mobility to Brain Health
Results from a clinical research study co-authored by physicians and scientists at the Pacific Neuroscience Institute (PNI) at Providence Saint John’s Health Center indicate a correlation between two modifiable risk factors – muscular strength and mobility – and brain atrophy among persons with Alzheimer’s disease.
Researchers quantified the relationship between a patient’s frailty and brain structure, and discovered that higher handgrip strength and mobility was related to larger brain volumes on the MRI scans of research participants, a marker of brain health. Results of the study will be published on Dec. 19 in the Journal of Alzheimer’s Disease1 and in 2023 in the JAD Handbook on the prevention of dementia – specifically Alzheimer’s disease.
The results of our study suggest that factors related to frailty are modifiable risk factors for brain health. Our research demonstrates that strength and mobility are directly related to the volumes of brain regions that influence cognition,” said Somayeh Meysami, M.D., lead author of the study, assistant professor of neurosciences at Saint John’s Cancer Institute and clinical research scientist at the Pacific Brain Health Center at PNI.
In total, 38 research participants with Alzheimer’s disease were enrolled in the clinical study. Researchers measured handgrip strength in patients’ dominant and non-dominant hands using a hand dynamometer, a small device that measures grip strength, and used the results to calculate handgrip asymmetry. Following this assessment, patients underwent a two-minute walk test to measure their mobility by how long it took them to walk a certain number of steps. Together, these tests were used to categorize patients as “frail” or “not frail.”
Following the evaluations, each patient’s brain regional volumes were measured using the Neuroreader by Brainreader, an FDA-cleared medical software program that uses MRI scans to detect brain volume loss.
Once the results of the evaluations were combined, researchers found that patients with higher non-dominant handgrip strength – or those who were considered “not frail” – had larger brain volumes in the hippocampus, and patients with higher two-minute walk test scores had larger hippocampal, frontal, temporal, parietal and occipital lobe volumes.
“We showed in our study that participants who were not frail were likely to have larger brain volumes and this is possible with volumetric quantification on MRI,” said Cyrus Raji, M.D., co-author of the clinical study and an assistant professor of radiology at Washington University in St. Louis.
Because up to 50% of Alzheimer’s risk is determined by modifiable risk factors that include those related to frailty, researchers believe the results of the study could have a larger impact on early interventions for patients at risk of developing Alzheimer’s and treatments for patients diagnosed with the disease.
“The Pacific Brain Health Center at PNI has been pioneering approaches to strengthen patients’ brain health through a combination of clinical interventions, in-depth diagnostic evaluations and cognitive-fitness training,” said David Merrill, M.D., an adult and geriatric psychiatrist who is corresponding and co-senior author on this study and director of the Pacific Brain Health Center at PNI. “Ultimately, we want to translate the findings from this study to our larger patient population to optimize brain health and improve frailty factors among patients with Alzheimer’s.”
1 Meysami, Somayeh et al. “Handgrip Strength is Related to Hippocampal and Lobar Brain Volumes in a Cohort of Cognitively Impaired Older Adults with Confirmed Amyloid Burden.” Journal of Alzheimer's disease : JAD, 10.3233/JAD-220886. 14 Dec. 2022, doi:10.3233/JAD-220886