James S. Andrews

Background Identification of novel risk factors for dementia in older adults could facilitate development of methods to identify patients most at risk and improve their cognitive outcomes. We aimed to determine whether lower appendicular lean mass (ALM), assessed by dual-energy x-ray absorptiometry (DXA), and lower grip strength are associated with a greater likelihood of incident dementia among older adults in the Health Aging and Body Composition Study (Health ABC). Methods Health ABC data from 1997 to 2008 were analyzed (n = 2 704). Baseline ALM to body mass index (BMI) ratio (ALMBMI) was assessed by DXA. Baseline grip strength was assessed by hand-held dynamometry. Incident dementia diagnosis was defined as either (i) dementia-related hospitalization plus a Modified Mini-Mental State Examination (3MS) score of ≤ 90; or (ii) record of prescription for anti-dementia medication; or (iii) decline of at least 1.5 SDs on the 3MS score compared to baseline. Cox proportional hazard models estimated associations of ALMBMI and grip strength with incident dementia over follow-up with and without adjusting for covariates, stratified by sex. Results Among older men, each standard deviation decrement in ALMBMI (adjusted hazard ratio [aHR]: 1.33; 95% confidence interval [CI]: 1.07, 1.65) or grip strength (aHR 1.22; 95% CI: 1.06, 1.41) was associated with increased likelihood of incident dementia. Conclusions Lower ALMBMI and grip strength may be important risk factors for the development of dementia among older men. How these factors may belong to a causal pathway of dementia must be elucidated in future work.

Patients with severe cases of coronavirus disease 2019 (COVID‐19) often become critically ill requiring intensive care unit (ICU) management. These individuals are at risk for developing ICU‐acquired weakness (ICUAW), a multifactorial condition in which polyneuropathy, myopathy, and/or disuse muscle atrophy result in motor weakness. This weakness is thought to contribute to the long‐term functional disability frequently observed in survivors of critical illness. This review discusses the current evidence regarding the epidemiology, pathophysiology, evaluation, risk factors, and rehabilitation‐specific management of ICUAW in patients with COVID‐19. Because of the novelty of COVID‐19, the exact prevalence of ICUAW is not well delineated among COVID‐19 patients. However, ICUAW has been reported in this population with retrospective studies showing weakness occurring in up to 45.5% of patients with severe COVID‐19. There are multiple risk factors for developing ICUAW among COVID‐19 patients, including premorbid health status, sepsis, multiple organ failure, mechanical ventilation, immobilization, neuromuscular blockade, corticosteroid use, and glycemic control. ICUAW is more likely to occur after prolonged mechanical ventilation and long hospital stays and can be diagnosed with manual muscle and electrodiagnostic testing. Although the long‐term sequela of COVID‐19 after ICU stays is not fully studied, increasing evidence indicates significant risk for this population developing long‐term functional impairments. Establishing postacute rehabilitation programs for COVID‐19 survivors will be important for recovery of endurance, mobility, and function.

Introduction Older adults with cognitive impairment, including those with Alzheimer's disease and related dementias, are particularly at risk for hospitalization and hospital‐associated disability. Understanding of key risk factors for hospital‐associated disability is limited. Sarcopenia, age‐related declines in muscle mass and strength, is common in older adults with cognitive impairment and may be an important risk factor for hospital‐associated disability. Methods Using data from the Health ABC Study, we examined associations of pre‐hospitalization appendicular lean mass (ALM) and grip strength with the development of a new activity of daily living (ADL) disability at the next annual assessment after hospitalization. Results Grip strength, but not ALM, was negatively associated with increased risk of hospital‐associated ADL disability, and this association was greater among those with cognitive impairment compared to those without. Discussion Lower grip strength may be an important risk factor for hospital‐associated ADL disability in older adults, particularly those with cognitive impairment.