Exercise Effects on Brain and Muscle Function in Acutely Hospitalized Older Patients Assessed by Functional Near-Infrared Spectroscopy

Acute medical illness and subsequent hospitalization are associated with several negative health consequences in older adults, even when the acute disease that caused the hospital admission is successfully treated. 1 Valenzuela P.L. Morales J.S. Castillo-García A. et al. Effects of exercise interventions on the functional status of acutely hospitalised older adults: A systematic review and meta-analysis. Ageing Res Rev. 2020; (61101076) Crossref Scopus (17) Google Scholar ,2 Martínez-Velilla N. Herrero A.C. Cadore E.L. et al. Iatrogenic nosocomial disability diagnosis and prevention. J Am Med Dir Assoc. 2016; 17: 762-764 Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar Loss of function in activities of daily living following hospitalization increases the risk of new disabilities, hospital readmissions, institutionalization, and death, and also increases the likelihood of developing cognitive impairment. 3 Ehlenbach W.J. Hough C.L. Crane P.K. et al. Association between acute care and critical illness hospitalization and cognitive function in older adults. JAMA. 2010; 303: 763-770 Crossref PubMed Scopus (351) Google Scholar In fact, hospital-acquired cognitive impairment is independently associated with multiple adverse outcomes, including increased length of hospital stay, nursing home admissions, and mortality. 4 Lucke J.A. van der Mast R.C. de Gelder J. et al. The six-item cognitive impairment test is associated with adverse outcomes in acutely hospitalized older patients: a prospective cohort study. Dement Geriatr Cogn Disord Extra. 2018; 8: 259-267 Crossref PubMed Scopus (5) Google Scholar Recent research indicates that physical exercise is a safe and effective strategy to enhance physical performance and cognition in older adults admitted to an acute care for the older unit. 5 Sáez de Asteasu M.L. Martínez-Velilla N. Zambom-Ferraresi F. et al. Assessing the impact of physical exercise on cognitive function in older medical patients during acute hospitalization: Secondary analysis of a randomized trial. PLoS Med. 2019; 16: e1002852 Crossref PubMed Scopus (27) Google Scholar ,6 Martínez-Velilla N. Casas-Herrero A. Zambom-Ferraresi F. et al. Effect of exercise intervention on functional decline in very elderly patients during acute hospitalization: A randomized clinical trial. JAMA Intern Med. 2019; 179: 28-36 Crossref PubMed Scopus (131) Google Scholar However, no studies have explored the physiological mechanisms underlying these improvements with regard to brain and muscle function after an intra-hospital exercise program. Functional near-infrared spectroscopy is a noninvasive technology that can measure muscle and neural activation by assessing changes in oxygenated and deoxygenated hemoglobin levels during the performance of a motor or cognitive task in a clinical practice condition. 7 Udina C. Avtzi S. Durduran T. et al. Functional near-infrared spectroscopy to study cerebral hemodynamics in older adults during cognitive and motor tasks: A review. Front Aging Neurosci. 2019; 11: 367 Crossref PubMed Scopus (21) Google Scholar Nevertheless, the findings across trials are inconsistent and it remains unclear whether there is a specific pattern to the changes in hemodynamics according to age and other determinants such as cognitive and functional status, and how these changes should be interpreted. 7 Udina C. Avtzi S. Durduran T. et al. Functional near-infrared spectroscopy to study cerebral hemodynamics in older adults during cognitive and motor tasks: A review. Front Aging Neurosci. 2019; 11: 367 Crossref PubMed Scopus (21) Google Scholar Therefore, we aimed to examine the effects of an intra-hospital exercise program on brain function, specifically the prefrontal cortex region, and also on muscle function in hospitalized older patients, assessed by functional near-infrared spectroscopy imaging.