Sarcopenia,Low Handgrip Strength,and Low Absolute Muscle Mass Predict Long-Term Mortality in Older Hospitalized Patients: An Observational Inception Cohort Study

ObjectiveSarcopenia is highly prevalent in hospitalized older patients and associated with short-term mortality. This study aimed to investigate whether sarcopenia and its measures handgrip strength (HGS) and muscle mass at hospital admission were associated with long-term mortality in a cohort of hospitalized older patients.DesignObservational, prospective, longitudinal inception cohort study.Setting and ParticipantsAcademic teaching hospital; patients age ≥70 years admitted to the internal medicine, acute admission, trauma, or orthopedic wards.MethodsHGS and muscle mass were measured at admission using a hand dynamometer and bioelectrical impedance analysis. Sarcopenia was determined based on the European Working Group on Sarcopenia in Older People definition. HGS and muscle mass (skeletal muscle mass index, appendicular lean mass, relative skeletal muscle mass) were expressed as sex-specific tertiles. The associations of sarcopenia, HGS, and muscle mass with mortality (during a follow-up of 3.4-4.1 years) were analyzed using Cox regression, adjusted for age, sex, comorbidity, and weight or height. Associations of HGS and muscle mass were stratified by sex.ResultsOut of 363 patients [mean age: 79.6 years (standard deviation: 6.4), 49.9% female] 49% died. Probable sarcopenia (prevalence of 53.7%) and sarcopenia (prevalence of 20.8%) were significantly associated with long-term mortality [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.08?2.17 and 1.71 95% CI 1.12?2.61, respectively]. Low HGS, skeletal muscle mass index, and appendicular lean mass were associated with a higher mortality risk (lowest tertile vs highest tertile: HR 2.660, 95% CI 1.40?5.05; HR 1.95, 95% CI 1.06?3.58 and HR 1.99 (95% CI 1.12?3.53) in male patients. No statistically significant associations of relative muscle mass with mortality were found.Conclusions and ImplicationsSarcopenia and its measures (low HGS and low absolute muscle mass at admission) predict long-term mortality in older hospitalized patients.     

Cognitive Function Improvements Mediate Exercise Intervention Effects on Physical Performance in Acutely Hospitalized Older Adults

ObjectivesAn individualized, multicomponent exercise program is effective to reverse the functional and cognitive decline that frequently occur during acute care hospitalization in older patients. The aim was to determine whether improvements in cognition mediate improvements in physical function in acutely hospitalized older patients.DesignA single-center, single-blind randomized clinical trial.Setting and ParticipantsAcute care for elderly (ACE) unit in a tertiary public hospital in Navarre (Spain). Hospitalized patients were randomly assigned to an exercise intervention (n = 185) or usual-care group (n = 185). The intervention consisted of a multicomponent exercise-training program performed during 5 to 7 consecutive days (2 sessions/day). The usual-care group received habitual hospital care, which included physical rehabilitation when needed.MeasuresThe main endpoints were changes in cognitive function assessed by the Mini-Mental State Examination test and verbal fluency ability, and changes in physical performance by the Short Physical Performance Battery from baseline to discharge. Mediation regression models were generated using ordinary least squares with the PROCESS version 3.2 to determine links between exercise-induced improvements.ResultsMediation regression model analysis indicated a significant and direct beneficial effect of physical exercise on physical function (β = 2.14; P < .0001), and a significant indirect effect of global cognitive function on the direct effect (indirect effect = 0.26; 0.10 to 0.49). Verbal fluency ability also had an indirect effect (0.32; 0.16 to 0.53) on the positive effect of exercise-training on physical function.Conclusions and ImplicationsCognitive function enhancements mediate physical function improvements in acutely hospitalized older adults after an individualized, multicomponent exercise-training program.ClinicalTrials.gov registration (NCT02300896)     

Malnutrition in Relation to Muscle Mass,Muscle Quality,and Muscle Strength in Hospitalized Older Adults

ObjectivesMuscle quality is an essential muscle metric, which can be assessed by measuring intermuscular adipose tissue (IMAT) and skeletal muscle radiodensity (SMD) via computed tomography (CT) images. We aimed to explore the associations of Global Leadership Initiative on Malnutrition (GLIM)–defined malnutrition with muscle mass, muscle quality, and muscle strength in hospitalized older adults.DesignA cross-sectional study.Setting and participantsHospitalized older patients.MethodsMalnutrition was defined by the GLIM criteria after screening by the Mini Nutrition Assessment–Short Form (MNA-SF). Chest CT images were used to segment skeletal muscle area (SMA) and IMAT, and to measure SMD. Skeletal muscle index (SMI) was calculated by SMA (cm²)/body height squared (m²). Handgrip strength (HGS) was measured using a digital dynameter. Univariate and multivariate logistic regression models were performed to calculate odds ratios (ORs) and 95% CIs.ResultsWe included 1135 patients. The MNA-SF score is positively associated with SMI, SMD, and HGS, but negatively associated with IMAT. Compared to patients with normal nutrition, patients with malnutrition had significantly lower SMD and HGS in both men and women. Women with malnutrition had significantly higher IMAT than women with normal nutrition, whereas men with malnutrition had significantly lower SMI than men with normal nutrition. After adjustment for confounders, SMI (adjusted OR 0.95, 95% CI 0.93, 0.98), SMD (adjusted OR 0.94, 95% CI 0.93, 0.98), and HGS (adjusted OR 0.91, 95% CI 0.89, 0.94) were significantly and negatively associated with malnutrition. IMAT appeared to be positively associated with malnutrition, but the result was not statistically significant (adjusted OR 1.03, 95% CI 1.00, 1.07).Conclusions and ImplicationsOur study provides new evidence regarding the association between handgrip strength and malnutrition in older inpatients. Moreover, a small association of chest CT-–derived muscle quality and mass with malnutrition is identified.     

Effect of Calcifediol on Physical Performance and Muscle Strength Parameters: A Systematic Review and Meta-Analysis

There is general agreement that optimal vitamin D status is necessary for bones, muscles, and general health, particularly in older adults, who are at higher risk of negative consequences of vitamin D deficiency, including sarcopenia; vitamin D supplementation is proposed as a potential intervention to mitigate sarcopenia. Several RCTs have reported that calcifediol (25(OH)D) was more potent than cholecalciferol in increasing plasma 25(OH)D. The present systematic review and meta-analysis aimed to summarize the effects of calcifediol on physical performance and muscle strength. We searched databases from inception to 1 January 2022 for studies investigating calcifediol on physical performance or muscle strength parameters. We calculated the difference between the means of follow-up vs. baseline data using standardized mean differences (SMD) and their 95% confidence intervals (CIs); a random-effect model was considered for all of the analyses. Seven RCTs were included in the meta-analysis. Calcifediol significantly improved gait speed (SMD = 2.500; 95%CI = 1.768–3.223; p < 0.0001); handgrip strength (n = 5446 participants, SMD = 0.532; 95%CI: 0.305–0.758; p < 0.0001; I² = 20.2%); and leg extension (n = 4318 participants, SMD = 0.641; 95%CI: 0.346 to 0.935; p < 0.0001; I² = 18.8%;) vs. baseline values. In conclusion, in this systematic review and meta-analysis, we observed that calcifediol may have a positive effect on muscle strength parameters, with less evidence on physical performance. These data further indicate the importance of vitamin D and, in particular, of calcifediol, not only on bone metabolism but also on muscle parameters and sarcopenia.     

Association between Changes in Nutrient Intake and Changes in Muscle Strength and Physical Performance in the SarcoPhAge Cohort

Muscle weakness and physical performance impairment are common geriatric conditions that raise morbidity and mortality. They are known to be affected by nutrition, but only a few longitudinal studies exist. This study aims to fill this gap by exploring the association, over 3 years, between variations of nutrient intakes, as well as, on one side, the variations of handgrip strength, as a surrogate of muscle strength, and on the other side, the physical performance, assessed by gait speed. Participants from the SarcoPhAge study, a Belgian cohort of people aged 65 years and older, were asked to complete a self-administered food frequency questionnaire (FFQ) at the second (T2) and the fifth (T5) year of follow-up. Daily macro- and micronutrient intakes were measured and their changes in consumption over the three years of follow-up were then calculated. The association between changes in nutrients consumption and the variations in muscle parameters were investigated through multiple linear regressions. Out of the 534 participants included in the cohort, 238 had complete data at T2 and T5 (median age of 72.0 years (70.0–78.0 years), 60.9% women). In the cross-sectional analysis, calories, omega-3 fatty acids, potassium, and vitamins D, A, and K intakes were positively correlated with muscle strength. In the longitudinal analysis, neither the gait speed nor the muscle strength changes were significantly impacted by the variations. Other longitudinal investigations with longer follow-up are required to improve knowledge about these interrelations.     

Factors Associated with Step Numbers in Acutely Hospitalized Older Adults: The Hospital-Activities of Daily Living Study

ObjectivesTo determine the number of steps taken by older patients in hospital and 1 week after discharge; to identify factors associated with step numbers after discharge; and to examine the association between functional decline and step numbers after discharge.DesignProspective observational cohort study conducted in 2015–2017.Setting and ParticipantsOlder adults (≥70 years of age) acutely hospitalized for at least 48 hours at internal, cardiology, or geriatric wards in 6 Dutch hospitals.MethodsSteps were counted using the Fitbit Flex accelerometer during hospitalization and 1 week after discharge. Demographic, somatic, physical, and psychosocial factors were assessed during hospitalization. Functional decline was determined 1 month after discharge using the Katz activities of daily living index.ResultsThe analytic sample included 188 participants [mean age (standard deviation) 79.1 (6.7)]. One month postdischarge, 33 out of 174 participants (19%) experienced functional decline. The median number of steps was 656 [interquartile range (IQR), 250–1146] at the last day of hospitalization. This increased to 1750 (IQR 675–4114) steps 1 day postdischarge, and to 1997 (IQR 938–4098) steps 7 days postdischarge. Age [β = ?57.93; 95% confidence interval (CI) ?111.15 to ?4.71], physical performance (β = 224.95; 95% CI 117.79–332.11), and steps in hospital (β = 0.76; 95% CI 0.46–1.06) were associated with steps postdischarge. There was a significant association between step numbers after discharge and functional decline 1 month after discharge (β = ?1400; 95% CI –2380 to ?420; P = .005).Conclusions and ImplicationsAmong acutely hospitalized older adults, step numbers double 1 day postdischarge, indicating that their capacity is underutilized during hospitalization. Physical performance and physical activity during hospitalization are key to increasing the number of steps postdischarge. The number of steps 1 week after discharge is a promising indicator of functional decline 1 month after discharge.     

Breakfast Protein Quality and Muscle Strength in Japanese Older Adults: A Community-Based Longitudinal Study

ObjectivesThe amount of breakfast protein intake is important for maintaining muscle strength. However, the effect of breakfast protein quality (ie, bioavailability) remains unclear. We investigated the association between breakfast protein quality and the incidence of muscle weakness.DesignLongitudinal study.Setting and ParticipantsHealthy older adults age 60–83 years without stroke, arthritis, Parkinson disease, or muscle weakness at baseline (maximum follow-up period and participations were 9.2 years and 5 times, respectively).MethodsWeakness was defined by the Asian Working Group for Sarcopenia 2019 criteria, using grip strength. Breakfast protein quality was evaluated using the protein digestibility–corrected amino acid score (PDCAAS), where higher scores represent higher quality, calculated from 3-day dietary records. Participants were classified according to sex-stratified tertiles of breakfast PDCAAS (ie, low to high groups). The association between PDCAAS and incident weakness was analyzed using the generalized estimating equation, after adjusting for sex, age, follow-up time, grip strength, body mass index, physical activity, cognition, education, smoking, economics, medical history, lunch and dinner PDCAASs, and energy and protein intake during 3 regular meals at baseline.ResultsOverall, 14.4% of the initial sample was excluded owing to a diagnosis of weakness-related diseases, and 58.3% (n = 701) had at least 1 follow-up measurement for inclusion in the analysis. The mean ± SD follow-up period was 6.9 ± 2.1 years; the cumulative number of participants was 3019, and 282 developed weakness. Using the low PDCAAS group as the reference, the adjusted odds ratios (95% CIs) for incident weakness in the middle and high PDCAAS groups were 0.71 (0.43–1.18) and 0.50 (0.29–0.86), respectively.Conclusions and ImplicationsHigher breakfast protein quality was associated with a reduction in incident weakness in older adults, independent of protein intake. These findings may highlight the role of protein quality for muscle health in older adults.     

Muscle Density,but Not Size,Correlates Well With Muscle Strength and Physical Performance

ObjectivesThere is increasing evidence that muscle volume and mass are poor predictors of muscle strength and physical performance. Other assessments of muscle quality such as skeletal muscle density measured by computed tomography (CT) may be more important. The aim of this study was to explore associations of muscle size and density with handgrip strength (HGS) and the Timed Up and Go test (TUG). We also hypothesized that the strength of these associations would depend on the specific muscle of muscle group, namely trunk, hip, and mid-thigh muscles.DesignCross-sectional study.Setting and ParticipantsUniversity hospital; 316 volunteers aged 59 to 85 years.MethodsHGS, TUG, and quantitative CT imaging of the lumber, hip, and mid-thigh were performed in volunteers. From the CT images, cross-sectional area and attenuation were determined for the gluteus muscle, trunk muscle at vertebrae L2 level, and mid-thigh muscle.ResultsIn men and women, associations of muscle area with TUG were insignificant after adjustment for age, height, and weight. Associations with HGS were only significant in men for the gluteus maximus and the mid-thigh but slopes were rather low (β < 0.20). Associations between muscle density and TUG/HGS were more pronounced, in particular for HGS. After adjustment, associations with TUG were significant in women for the gluteus maximus and trunk muscle even (β ?0.06, P .001 and β ?0.07, P .031, respectively).Conclusions and ImplicationsMuscle density is more strongly associated with muscle strength than muscle size andin women muscle density was also more strongly associated than muscle size with physical performance. Therefore, muscle density may represent a more clinically meaningful surrogate of muscle performance than muscle size. Muscle density measurements of trunk and gluteus muscles can be easily obtained from routine CT scan and, therefore, may become an important measurement to diagnose and screen for sarcopenia.     

Association of Water Intake with Hand Grip Strength in Community-Dwelling Older Adults

Although recent clinical studies have suggested that water intake enhances muscle mass, its impact on muscle strength remain unclear, especially in older adults. This cross-sectional, population-based study using a representative sample of Koreans investigated the relationship of water intake with hand grip strength (HGS) in 4443 older adults, including 2090 men aged ≥50 years and 2253 postmenopausal women. A digital grip strength dynamometer was used for HGS assessment. Low muscle strength was defined by the Korean-specific HGS cut-off value and adequate water intake was defined according to the Korean dietary reference intakes. In an unadjusted model, water intake was significantly higher in men and women without than with low muscle strength (both p < 0.001), but this difference disappeared after adjustment for confounding variables in both men (p = 0.050) and women (p = 0.245). Similarly, the correlation between water intake and HGS, the difference in HGS depending on adequate water intake status, and the risk of low muscle strength depending on water intake quartile were significant only in the unadjusted model. These data indicate that factors such as age, body size, and resistance exercise contribute to improvements in HGS in older adults, whereas water intake may not.     

Sarcopenia,Diet, Physical Activity and Obesity in European Middle-Aged and Older Adults: The LifeAge Study

The revised European consensus defined sarcopenia as a progressive and generalized skeletal muscle disorder that is associated with an increased likelihood of adverse outcomes including falls, fractures, physical disability and mortality. The aim of this study was to determine the prevalence of sarcopenia and analyse the influence of diet, physical activity (PA) and obesity index as risk factors of each criteria of sarcopenia. A total of 629 European middle-aged and older adults were enrolled in this cross-sectional study. Anthropometrics were assessed. Self-reported PA and adherence to the Mediterranean diet were evaluated with the Global Physical Activity Questionnaire (GPAQ) and Prevention with Mediterranean Diet questionnaire (PREDIMED), respectively. The functional assessment included handgrip strength, lower body muscle strength, gait speed and agility/dynamic balance. Of the participants, 4.84% to 7.33% showed probable sarcopenia. Sarcopenia was confirmed in 1.16% to 2.93% of participants. Severe sarcopenia was shown by 0.86% to 1.49% of participants. Male; age group ≤65 years; lower body mass index (BMI); high levels of vigorous PA; and the consumption of more than one portion per day of red meat, hamburgers, sausages or cold cuts and/or preferential consumption of rabbit, chicken or turkey instead of beef, pork, hamburgers or sausages (OR = 0.126–0.454; all p < 0.013) resulted as protective factors, and more time of sedentary time (OR = 1.608–2.368; p = 0.032–0.041) resulted as a risk factor for some criteria of sarcopenia. In conclusion, age, diet, PA, and obesity can affect the risk of having low muscle strength, low muscle mass or low functional performance, factors connected with sarcopenia.     

Preserved Lower Limb Muscle Mass Prevents Insulin Resistance Development in Nondiabetic Older Adults

ObjectiveTo investigate roles of sarcopenia indexes in prediction of development of insulin resistance in nondiabetic older adults.DesignA 2-year follow-up cohort.Setting and participantsThe Tanno-Sobetsu study, a prospective observational cohort, included 194 community-dwelling nondiabetic older adults during 2017-2019.MethodsLower limb, upper limb, appendicular, and trunk muscle masses by a bioelectrical impedance analysis, grip strength, knee extension torque, and walking speed were measured in study participants aged ≥65 years (79 men and 115 women) at baseline. Muscle mass and strength were divided by the weight, and then multiplied by 100 to calculate the weight ratio (%). Insulin resistance was assessed by homeostasis model (HOMA-IR) at baseline, and the study participants whose HOMA-IR was less than 1.73 at baseline were followed for a maximum of 2 years. The study endpoint was development of insulin resistance defined as HOMA-IR ≥1.73. The adjusted hazard ratio (HR) of each sarcopenia component for development of insulin resistance was calculated.ResultsLower limb muscle mass (HR 0.88, 95% CI 0.79-0.98) and appendicular muscle mass (HR 0.89, 95% CI 0.81-0.99), but not other sarcopenia components, were associated with the development of insulin resistance, independently of sex and age, HOMA-IR, and waist circumference at baseline.Conclusions and ImplicationsThe loss of lower limb muscle mass is a significant risk factor for development of insulin resistance independently of obesity in nondiabetic older adults. The lower limb muscle mass may be a novel target of interventions for the prevention of diabetes in older adults.     

Impact of Malnutrition Status on Muscle Parameter Changes over a 5-Year Follow-Up of Community-Dwelling Older Adults from the SarcoPhAge Cohort

This study aimed to assess the impact of malnutrition on the 5-year evolution of physical performance, muscle mass and muscle strength in participants from the SarcoPhAge cohort, consisting of community-dwelling older adults. The malnutrition status was assessed at baseline (T0) according to the “Global Leadership Initiatives on Malnutrition” (GLIM) criteria, and the muscle parameters were evaluated both at T0 and after five years of follow-up (T5). Lean mass, muscle strength and physical performance were assessed using dual X-ray absorptiometry, handgrip dynamometry, the short physical performance battery test and the timed up and go test, respectively. Differences in muscle outcomes according to nutritional status were tested using Student’s t-test. The association between malnutrition and the relative 5-year change in the muscle parameters was tested using multiple linear regressions adjusted for several covariates. A total of 411 participants (mean age of 72.3 ± 6.1 years, 56% women) were included. Of them, 96 individuals (23%) were diagnosed with malnutrition at baseline. Their muscle parameters were significantly lower than those of the well-nourished patients both at baseline and after five years of follow-up (all p-values < 0.05), except for muscle strength in women at T5, which was not significantly lower in the presence of malnutrition. However, the 5-year changes in muscle parameters of malnourished individuals were not significantly different than those of well-nourished individuals (all p-values > 0.05).     

Grip Strength and Sarcopenia Predict 2-Year Cognitive Impairment in Community-Dwelling Older Adults

ObjectivesUsing the Asian Working Group for Sarcopenia (AWGS2019) and the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria, this study examined associations of sarcopenia and its components with specific domains of cognitive impairment over time.DesignA prospective cohort study with a 2-year follow-up.Setting and ParticipantsThis study is part of the Taiwan Initiatives for Geriatric Epidemiological Research (TIGER), which recruited participants aged 65 years old who attended the senior health checkup program at National Taiwan University Hospital (NTUH).MethodsGrip strength was measured using a handgrip dynamometer. Walking speed (m/s) was measured as the time required to walk 8 feet. Muscle mass was measured by performing a bioelectrical impedance analysis. Global cognition (assessed using the Taiwanese version of the Montreal Cognitive Assessment) and 4 cognitive domains (memory, executive function, verbal fluency, and attention) were assessed over time. Associations of sarcopenia and its components with cognitive impairment were evaluated after stratification by sex using generalized linear mixed models adjusted for essential covariates for cognitive impairment.ResultsCompared with robust women, those with severe sarcopenia were more likely to have a global cognitive impairment over time (β = ?0.87, P = .03 based on AWGS2019 criteria and β = ?1.07, P = .02 based on the EWGSOP2 criteria). Among men, low grip strength was associated with poor scores on measures of global cognition (β = ?0.80, P = .03), executive function (β = ?0.35, P = .001), verbal fluency (β = ?0.31, P = .02), and attention (β = ?0.34, P = .008) over time.Conclusions and ImplicationsSevere sarcopenia predicted global and specific domains of cognitive impairment in older adults. Poor grip strength predicted cognitive impairment in men but not in women. A screen for sarcopenia severity and low muscle strength may be used to identify the risk of cognitive impairment.     

The Dietary Inflammatory Index Is Associated with Low Muscle Mass and Low Muscle Function in Older Australians

Age-associated chronic, low grade systemic inflammation has been recognised as an important contributing factor in the development of sarcopenia; importantly, diet may regulate this process. This cross-sectional study examined the association of diet-related inflammation with components of sarcopenia. Participants (n = 809) aged 60–95 years from the Geelong Osteoporosis Study were studied. Body composition was measured by dual energy X-ray absorptiometry. In this study, low appendicular lean mass (ALM/height², kg/m²) was defined as T-score < −1 and low muscle function as Timed-Up-and-Go >10 s over 3 m (TUG > 10). Dietary inflammatory index (DII^®) scores, based on specific foods and nutrients, were computed using dietary data collected from a food frequency questionnaire. Associations between DII scores and low muscle mass and low muscle function, alone and combined, were determined using linear and logistic regression. After adjusting for covariates, higher DII score was associated with lower ALM/height² (β −0.05, standard error (SE) 0.02, p = 0.028), and higher natural log-transformed (ln) (TUG) (β 0.02, standard error 0.01, p = 0.035) and higher likelihood for these components combined (odds ratio 1.33, 95% confidence interval 1.05 to 1.69, p = 0.015). A pro-inflammatory diet, as indicated by higher DII score, is associated with lower muscle mass, poorer muscle function and increased likelihood for the combination of low muscle mass and low muscle function. Further studies investigating whether anti-inflammatory dietary interventions could reduce the risk of sarcopenia are needed.     

The Course of Geriatric Syndromes in Acutely Hospitalized Older Adults: The Hospital-ADL Study

Objectives

To establish the prevalence and course of geriatric syndromes from hospital admission up to 3 months postdischarge and to determine the probability to retain geriatric syndromes over the period from discharge until 3 months postdischarge, once they are present at admission.

Assessing Additional Characteristics of Muscle Function With Digital Handgrip Dynamometry and Accelerometry: Framework for a Novel Handgrip Strength Protocol

Maximal handgrip strength (HGS) is a convenient and reliable, but incomplete, assessment of muscle function. Although low HGS is a powerful predictor of poor health, several limitations to maximal HGS exist. The predictive value of HGS is restricted because low HGS is associated with a wide range of unspecified health conditions, and other characteristics of muscle function aside from strength capacity are not evaluated. Current HGS protocol guidelines emphasize the ascertainment of maximal force, which is only a single muscle function characteristic. Muscle function is intrinsically multivariable, and assessing other attributes in addition to strength capacity will improve screenings for age-related disabilities and diseases. Digital handgrip dynamometers and accelerometers provide unique opportunities to examine several aspects of muscle function beyond strength capacity, while also maintaining procedural ease. Specifically, digital handgrip dynamometry and accelerometry can assess the rate of force development, submaximal force steadiness, fatigability, and task-specific tremoring. Moreover, HGS protocols can be easily refined to include an examination of strength asymmetry and bilateral strength. Therefore, evaluating muscle function with new HGS technologies and protocols may provide a more comprehensive assessment of muscle function beyond maximal strength, without sacrificing feasibility. This Special Article introduces a novel framework for assessing multiple attributes of muscle function with digital handgrip dynamometry, accelerometry, and refinements to current HGS protocols. Such framework may aid in the discovery of measures that better predict and explain age-related disability, biological aging, and the effects of comorbid diseases that are amenable to interventions. These additional HGS measures may also contribute to our understanding of concepts such as resilience. Using sophisticated HGS technologies that are currently available and modernizing protocols for developing a new muscle function assessment may help transform clinical practice by enhancing screenings that will better identify the onset and progression of the disabling process.