Sources:
https://pubmed.ncbi.nlm.nih.gov/36530088/
https://www.iospress.com/news/pni-study-links-muscular-strength-and-mobility-to-brain-health#.Y8lWB8gbB-E.linkedin
January, 2023

Authors:
Somayeh Meysami, Cyrus A. Raji, Ryan M. Glatt, Emily S. Popa, Aarthi S. Ganapathi, Tess Bookheimer, Colby B. Slyapich, Kyron P. Pierce, Casey J. Richards, Melanie G. Lampa, Jaya M. Gill, Molly K. Rapozo, John F. Hodes, Ynez M. Tongsond, Claudia L. Wonga, Mihae Kim, Verna R. Porter, Scott A. Kaiser, Stella E. Panos, Richelin V. Dye, Karen J. Miller, Susan Y. Bookheimer, Neil A. Martin, Santosh Kesari, Daniel F. Kelly, Jennifer E. Bramen, Prabha Siddarth, and David A. Merrill.

Objective

Investigation of the correlation between muscular (handgrip) strength, mobility, and brain atrophy among persons with Alzheimer’s disease quantified on brain MR imaging.

Method

38 participants with Alzheimer’s disease dementia were selected: Biomarker evidence of amyloidosis and impaired cognition. Handgrip strength on dominant and non-dominant hands was measured with a hand dynamometer. Handgrip asymmetry was calculated. Two-minute walk test (2MWT) mobility evaluation was combined with handgrip strength to identify non-frail versus frail persons. Brain MRI volumes were quantified with Neuroreader®. Multiple regression adjusting for age, sex, education, handedness, body mass index, and head size modeled handgrip strength, asymmetry and 2MWT with brain volumes. The researchers modeled non-frail versus frail status relationships with brain structures by analysis of covariance.

Following the evaluations, each patient’s brain regional volumes were measured using Neuroreader® to detect brain volume loss.

Cyrus A. Raji, co-author of the clinical study and assistant professor of radiology at Washington University in St. Louis, said:

“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.”

Results

Higher non-dominant handgrip strength was associated with larger volumes in the hippocampus (p = 0.02). Dominant handgrip strength was related to higher frontal lobe volumes (p = 0.02). Higher 2MWT scores were associated with larger hippocampal (p = 0.04), frontal (p = 0.01), temporal (p = 0.03), parietal (p = 0.009), and occipital lobe (p = 0.005) volumes. Frailty was associated with reduced frontal, temporal, and parietal lobe volumes.

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.

“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.

“The Pacific Brain Health Center at PNI has been pioneering approaches to strengthen patients’ brain through a combination of clinical interventions, in-depth diagnostic evaluations and cognitive training. 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.” 

– David Merril, M.D. co-senior author on this study and director of the Pacific Brain Health Center at PNI.  

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 larger impact on early interventions for patients at risk of developing Alzheimer’s and treatments for patients diagnosed with the disease.

Results of the study was published on December 14, 2022, in the Journal of Alzheimer’s Disease and will be published in 2023 in the JAD Handbook on the prevention of dementia – specifically Alzheimer’s disease.
DOI: 10.3233/JAD-220886

Read the full study here