Implications of low muscle mass across the continuum of care: a narrative review

Ethnic differences in CT derived abdominal body composition measures: a comparative retrospect pilot study between European and Inuit study population

Understanding ethnic variations in body composition is crucial for assessing health risks. Universal models may not suit all ethnicities, and there is limited data on the Inuit population. This study aimed to compare body composition between Inuit and European adults using computed tomography (CT) scans and to investigate the influence of demographics on these measurements. A retrospective analysis was conducted on 50 adults (29 Inuit and 21 European) who underwent standard trauma CT scans. Measurements focused on skeletal muscle index (SMI), various fat indices, and densities at the third lumbar vertebra level, analyzed using the Wilcoxon-Mann-Whitney test and multiple linear regression. Inuit women showed larger fat tissue indices and lower muscle and fat densities than European women. Differences in men were less pronouncehd, with only Intramuscular fat density being lower among Inuit men. Regression indicated that SMI was higher among men, and skeletal muscle density decreased with Inuit ethnicity and age, while visceral fat index was positively associated with age. This study suggests ethnic differences in body composition measures particularly among women, and indicates the need for Inuit-specific body composition models. It higlights the importance of further research into Inuit-specific body composition measurements for better health risk assessment.

Resistance Exercise and Skeletal Muscle-Related Outcomes in Patients with Cancer: A Systematic Review

BACKGROUND

Skeletal muscle loss is prevalent throughout the cancer continuum and correlated with morbidity and mortality. Resistance exercise has been trialed to mitigate skeletal muscle loss. This systematic review summarizes and qualitatively synthesizes the effects of resistance exercise on muscle-related outcomes in adult cancer populations, including skeletal muscle mass, performance and muscle-related biomarkers.

METHODS

The systematic review protocol was developed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). We searched electronic databases including AMED, CENTRAL, CINAHL, CIRRIE, EMBASE, MEDLINE, PEDro, REHABDATA, Scopus, and SPORTDiscus from inception to December 2021. We included randomized controlled trials that investigated the effects of resistance exercise on muscle-related outcomes in adult cancer populations. Interventions that involved any resistance exercise were included. Muscle-related outcomes were categorized as skeletal muscle mass (e.g., lean mass, appendicular muscle mass), muscle performance (e.g., muscle strength, physical function), and muscle-related biomarkers (e.g., muscle cells, metabolic/inflammatory markers). Risk of bias (RoB) was assessed using the Cochrane ROB tool.

RESULTS

A total of 102 studies from 101 randomized controlled trials were included. The majority of studies focused on breast cancer (46%) and those who completed treatment (43%). Resistance exercise interventions were largely 3-4 months long (48%), combined with aerobic exercise (56%), at a vigorous intensity (25%), and in-person/supervised settings (57%). Among the studies assessing muscle mass, performance, and biomarkers ( n = 42, 83, and 22, respectively), resistance exercise interventions improved upper/lower body or appendicular muscle mass (67%-100%), muscle strength (61%-68%), and physical function (74%-100%). Most biomarkers did not show significant changes (75%-100%) or showed inconsistent results.

CONCLUSIONS

Generally, resistance exercise had positive effects on skeletal muscle mass and performance with no negative effects compared to controls. Our findings demonstrated that resistance exercise may be an effective strategy to attenuate deterioration or exert improvements in muscle mass and performance outcomes.

Serum creatinine and serum cystatin C as an index of muscle mass in adults

PURPOSE OF REVIEW

Serum creatinine reflects both muscle mass and kidney function. Serum cystatin C has recently been recommended as an additional marker for estimating kidney function, and use of both markers together may provide an index of muscle mass. This review aims to describe the biological basis for and recent research examining the relationship of these markers to muscle mass in a range of adult populations and settings.

RECENT FINDINGS

This review identified 67 studies, 50 of which had direct measures of muscle mass, and almost all found relationships between serum creatinine and cystatin C and muscle mass and related outcomes. Most studies have been performed in older adults, but similar associations were found in general populations as well as in subgroups with cancer, chronic kidney disease (CKD), and other morbid conditions. Creatinine to cystatin C ratio was the measure examined the most often, but other measures showed similar associations across studies.

SUMMARY

Measures of serum creatinine and cystatin C together can be an index of muscle mass. They are simple and reliable measures that can be used in clinical practice and research. Further study is needed to determine actionable threshold values for each measure and clinical utility of testing and intervention.

Skeletal muscle dysfunction with advancing age

As a result of advances in medical treatments and associated policy over the last century, life expectancy has risen substantially and continues to increase globally. However, the disconnect between lifespan and 'health span' (the length of time spent in a healthy, disease-free state) has also increased, with skeletal muscle being a substantial contributor to this. Biological ageing is accompanied by declines in both skeletal muscle mass and function, termed sarcopenia. The mechanisms underpinning sarcopenia are multifactorial and are known to include marked alterations in muscle protein turnover and adaptations to the neural input to muscle. However, to date, the relative contribution of each factor remains largely unexplored. Specifically, muscle protein synthetic responses to key anabolic stimuli are blunted with advancing age, whilst alterations to neural components, spanning from the motor cortex and motoneuron excitability to the neuromuscular junction, may explain the greater magnitude of function losses when compared with mass. The consequences of these losses can be devastating for individuals, their support networks, and healthcare services; with clear detrimental impacts on both clinical (e.g., mortality, frailty, and post-treatment complications) and societal (e.g., independence maintenance) outcomes. Whether declines in muscle quantity and quality are an inevitable component of ageing remains to be completely understood. Nevertheless, strategies to mitigate these declines are of vital importance to improve the health span of older adults. This review aims to provide an overview of the declines in skeletal muscle mass and function with advancing age, describes the wide-ranging implications of these declines, and finally suggests strategies to mitigate them, including the merits of emerging pharmaceutical agents.

Is Type and Grade of Emphysema Important for Bone Mineral Density and Aortic Calcifications?

Background: Chronic obstructive pulmonary disease has extrapulmonary manifestations, such as cardiovascular diseases and osteoporosis. The purpose of this research was to determine the relationship between the type and extent of emphysema with thoracic aorta calcification (TAC) and bone mineral density (BMD) at Th4, Th8, and L1 vertebrae. Methods: Emphysema was described by computed tomography parameters (both Fleischner classification and low attenuation value percentage, LAV%) and the clinical FEV1/FVC ratio (Tiffeneau-Pinelli index, TI, TI < 0.7; TI > 0.7). Results: Of 200 included patients (median age 64, 33% women), signs of clinical obstruction (TI) were observed in 104 patients, which had significantly lower BMD and more heavy TAC. BMD correlated negatively with LAV%, Rho = -0.16 to -0.23, while a positive correlation of aortic calcification with LAV% was observed, Rho = 0.30 to 0.33. Multiple linear regression showed that age and TI < 0.7 were independent predictors of BMD, β = -0.20 to -0.40, and β = -0.21 to -0.25; age and hypercholesterolemia were independent predictors of TCA, β = 0.61 and β = 0.19. Conclusions: Clinical TI and morphological LAV% parameters correlated with BMD and TAC, in contrast to Fleischer-graded emphysema, which showed no correlation. However, only TI was an independent predictor of BMD, while the morphologically described type and extent of emphysema could not independently predict any extrapulmonary manifestation.

Skeletal muscle quantity and quality evaluation in heart failure: comparing thoracic versus abdominopelvic CT approaches

Given the critical role of skeletal muscle in healthy aging, low muscle mass (myopenia) and quality (myosteatosis) can be used as predictors of poor functional and cardiometabolic outcomes. Myopenia is also a part of sarcopenia and malnutrition diagnostic criteria. However, there is limited evidence for using chest computed tomography (CT) to evaluate muscle health. We aimed to compare chest CT landmarks to the widely used L3 vertebra for single-slice skeletal muscle evaluation in patients with heart failure (HF). Patients admitted for acute decompensated HF between January 2017 and December 2018 were retrospectively analyzed. Body composition measurements were made on CT of the chest and abdomen/pelvis with or without contrast one month before discharge. Skeletal muscle index (SMI) and intermuscular adipose tissue percentage (IMAT%) were calculated at several thoracic levels (above the aortic arch, T8, and T12) and correlated to the widely used L3 level. A total of 200 patients were included, 89 (44.5%) female. The strongest correlation of thoracic SMI (for muscle quantity) and IMAT% (for muscle quality) with L3 was at the T12 level (r = 0.834, p < 0.001 and r = 0.757, p < 0.001, respectively). Cutoffs to identify low muscle mass for T12 SMI (derived from the lowest sex-stratified L3 SMI tertile) were 31.1 cm²/m² in men and 26.3 cm²/m² in women. SMI and IMAT% at T12 had excellent correlations with the widely used L3 level for muscle quantity and quality evaluation in patients with HF.

Muscle Mass as a Biomarker for Health Status and Function in Pediatric Individuals with Neuromuscular Disabilities: A Systematic Review

This systematic review aims to investigate the relationship between muscle mass and specific health outcomes in pediatric populations with neuromuscular disorders. A search was performed for any relevant studies published in English from 1996 to 2023 in five databases. To be included in this analysis, articles must have had participants with an average age ≤21, focus on children with neuromuscular disabilities, and primarily examine relationships between muscle mass and any functional or health outcomes measure. Studies including typically developing children were used to contrast and enhance findings. Thirty-two studies were included, with 10,129 unique individuals represented: seventeen studies focused on healthy/typically developing children; seven on children with cerebral palsy; three on children with Duchenne muscular dystrophy; two on children with sarcopenia; and one study each on children with osteoporosis, congenital muscular dystrophy, and other various neurologic disorders. Thirteen studies assessed functional outcomes, ten assessed bone outcomes, and nine assessed other cardiovascular/metabolic outcomes. All of the included studies demonstrated relationships between muscle mass and respective outcomes in varying measures. The results of this review demonstrate that there is a consistently recognized relationship between muscle mass and important health outcomes in children, supporting clinically targeting muscle mass as a means to optimize desired outcomes.

Influence of weight-adjusted contrast enhancement on computed tomography-derived skeletal muscle measures: a retrospective proof-of-concept comparative study between Danish females and males

BACKGROUND

Computed tomography (CT) has an underutilized potential for evaluating body composition in clinical settings. Often conducted with intravenous contrast (IVC), CT scans yield unused body composition data due to unclear effects on skeletal muscle area (SMA), skeletal muscle index (SMI), and muscle density (SMD).

OBJECTIVES

This study investigates whether weight-adjusted IVC influences SMA, SMI, and SMD differently in females and males compared with noncontrast abdominal CT. In addition, the study explores associations between contrast and noncontrast-assessed SMA, SMI, SMD, and demographic factors.

METHODS

A comparative observational retrospective study was conducted on Danish patients who underwent consecutive 4-phased contrast-enhanced abdominal CT scans (noncontrast, arterial, venous, and late venous phases). Muscle measures were evaluated using validated semiautomated threshold-based software by 3 independent raters.

RESULTS

The study included 72 patients (51 males and 21 females) with a mean age of 59 (55 and 62) y. Weight-adjusted IVC increased SMA by ≤3.28 cm2 (95% confidence interval [CI]: 2.58, 3.98) corresponding to 2.4% (1.8, 2.9) in the late venous phase compared with noncontrast CT. Analysis between sexes showed no difference in the effects of IVC on SMA and SMI between females and males. However, females exhibited a higher increase in SMD during the venous by a mean of 1.7 HU (0.9; 2.5) and late venous phases with a mean HU of 1.80 (1.0; 2.6) compared with males. Multivariate regression analysis indicated an association between the differences in SMD and sex during venous (-1.38, 95% CI: -2.48, -0.48) and late venous phases (-1.23, 95% CI: -2.27, -0.19).

CONCLUSIONS

Weight-adjusted IVC leads to increased SMA, SMI, and SMD. Although SMA and SMI differences were consistent across the sexes, females exhibited a significantly higher SMD increase than males in the venous and late venous phases. Further investigations are necessary to determine the applicability of SMD as a muscle quality proxy in IVC CT scans.

Comparison between single-muscle evaluation and cross-sectional area muscle evaluation for predicting the prognosis in patients with oral squamous cell carcinoma: a retrospective cohort study

Introduction

The most effective method of assessing sarcopenia has yet to be determined, whether by single muscle or by whole muscle segmentation. The purpose of this study was to compare the prognostic value of these two methods using computed tomography (CT) images in patients with oral squamous cell carcinoma (OSCC).

Materials and methods

Sex- and age-adjusted Cox proportional hazards models were employed for each parameter of sarcopenia related to overall survival, disease-free survival, and disease-specific survival. Harrell's concordance index was calculated for each model to assess discriminatory power.

Results

In this study including 165 patients, a significant correlation was found between the CT-based assessment of individual muscles and their cross-sectional area. Single muscle assessments showed slightly higher discriminatory power in survival outcomes compared to whole muscle assessments, but the difference was not statistically significant, as indicated by overlapping confidence intervals for the C-index between assessments. To further validate our measurements, we classified patients into two groups based on intramuscular adipose tissue content (P-IMAC) of the spinous process muscle. Analysis showed that the higher the P-IMAC value, the poorer the survival outcome.

Conclusion

Our findings indicate a slight advantage of single-muscle over whole-muscle assessment in prognostic evaluation, but the difference between the two methods is not conclusive. Both assessment methods provide valuable prognostic information for patients with OSCC, and further studies involving larger, independent cohorts are needed to clarify the potential advantage of one method over the other in the prognostic assessment of sarcopenia in OSCC.

Estimating Muscle Mass Using D3-Creatine Dilution: A Narrative Review of Clinical Implications and Comparison With Other Methods

BACKGROUND

The D3-creatine (D3-Cr) dilution method is of emerging interest for estimating total-body skeletal muscle mass. This review explores the association of muscle mass estimated via D3-Cr with various clinical outcomes and provides a summary of the literature comparing D3-Cr with other body composition techniques.

METHODS

A literature search was conducted on PubMed/MEDLINE and Web of Science for studies using D3-Cr to measure muscle in adult populations (ie, ≥18 years old) from inception until September 2023.

RESULTS

Out of the 23 included studies, 15 investigated the correlation between D3-Cr and clinical outcomes. More consistent associations were reported for mortality (100%, n = 2), mobility disability (100%; n = 5), falls and fractures (100%; n = 3), physical performance (63.3%; n = 11), muscle strength (44.4%; n = 9), and muscle composition (33.3%; n = 3). However, conflicting findings were also reported for such correlations. Among the 23 studies, 14 compared D3-Cr-estimated muscle with other body composition techniques, including magnetic resonance imaging (MRI) as a reference method. Strong and positive correlations were found between D3-Cr and MRI. Nonetheless, variations in muscle measurements were noted, with differences in D3-Cr values ranging from 0.62 kg lower to 13.47 kg higher compared to MRI.

CONCLUSIONS

D3-Cr-estimated muscle mass may be a valuable predictor of clinical outcomes showing consistent associations with falls and fractures, mobility disability, and mortality. However, less consistent associations were found with muscle strength and composition, and physical performance. Although a strong correlation exists between D3-Cr-estimated muscle mass and MRI measurements, under- or overestimation may occur.

Impact of dietary sodium restriction on falls among middle-aged and older adults: Results of an 8-year longitudinal study

AIM

This study aimed to understand the relationship between dietary sodium restriction (DSR) and falling experiences in middle-aged and older adults.

METHODS

The 8-year follow-up data from the Taiwan Longitudinal Study on Aging, covering 5131 individuals aged ≥50 years, were analyzed using random-effects panel logit models. Participants were asked to indicate whether they were told by a physician to reduce or avoid sodium intake from food and whether they had had fall experiences during the past year. We modelled falling experiences as a function of DSR (independent variable), involuntary body weight loss and walking difficulty (mediators), and chronic diseases (moderator), adjusting for individual-level characteristics.

RESULTS

Individuals with DSR were at a higher risk of falls compared with those with no DSR (adjusted odds ratio [AOR] = 1.30, 95% confidence interval [CI] = 1.11-1.53). This effect was more prevalent in individuals with a history of stroke (AOR = 1.85, 95% CI = 1.19-2.87). Those told to reduce sodium intake by a physician were likely to lose weight involuntarily (AOR = 1.20, 95% CI = 1.05-1.36) and had difficulty walking up two or three flights of stairs alone (AOR = 2.38, 95% CI = 1.73-3.27), which mediated the effect of DSR on increased fall risk (AOR = 1.15, 95% CI = 0.95-1.38). We found a temporal effect: participant reactions to short- and mid-term DSR were significant.

CONCLUSIONS

DSR was associated with a greater likelihood of falls among middle-aged and older adults, particularly those with a history of stroke. Geriatr Gerontol Int 2024; 24: 292-299.

Muscularity of older trauma patients at intensive care unit admission, association with functional outcomes, and relationship with frailty: A retrospective observational study

BACKGROUND

Older individuals are at an increased risk of delayed recovery following a traumatic injury. Measurement of muscularity and frailty at hospital admission may aid with prognostication and risk stratification.

OBJECTIVE

This study aimed to describe muscularity at intensive care unit (ICU) admission in patients admitted following trauma and assess the relationship between muscularity and clinical, long-term functional outcomes and frailty at ICU admission.

METHODS

This retrospective study utilised data from a prospective observational study investigating frailty in patients aged ≥50 years, admitted to the ICU following trauma. Patients were eligible if they had a Computed Tomography (CT) scan including the third lumbar vertebra at ICU admission. Specialist software was used to quantify CT-derived skeletal muscle cross-sectional area. Muscularity status was classified as normal or low using published sex-specific cut-points. Demographic data, frailty, clinical, and long-term functional outcomes (Glasgow Outcome Scale-Extended and EQ-5DL-5L Visual analogue scale and utility score) were extracted from the original study.

RESULTS

One hundred patients were screened; 71 patients had a CT scan on admission with 66 scans suitable for muscle assessment. Patients with low muscularity (n = 25, 38%) were older and had a higher Acute Physiology and Chronic Health Evaluation II score and lower body mass index than patients with normal muscularity. Low muscularity was associated with frailty at admission (32% vs 5%, p = 0.005) but not with long term outcomes at 6 or 12 months. As a continuous variable, lower muscle cross-sectional area was associated with a poorer outcome on the Glasgow Outcome Scale-Extended at 6 months (mean [standard deviation]: 150 [43] and 180 [44], respectively; p = 0.014), no association was observed after adjustment for age p = 0.43).

CONCLUSION

In a population of older adults hospitalised following trauma, low muscularity at ICU admission was prevalent. Low muscularity was associated with frailty but not long-term functional outcomes. Larger studies are warranted to better understand the relationship between muscularity and long-term functional outcomes.

Association between animal protein intake, oral frailty and calf circumference in middle-aged and older adults: a cross-sectional analysis from the Shika study

OBJECTIVE

To investigate the relationship between oral frailty (OF), nutrient intake and calf circumference (CC) in middle-aged and older adults.

DESIGN

Cross-sectional study.

SETTING

Residents of four model districts of Shika town, Ishikawa Prefecture, Japan, using data from November 2017 to February 2018.

PARTICIPANTS

One hundred and ninety-four residents aged ≥50 years in four model districts of Shika town. The OF total score ≥3 was defined as OF. Participants were divided into OF and non-OF groups and divided into the low-CC/kg and the high-CC/kg groups.

OUTCOME MEASURES

The primary outcome is to use a two-way analysis of covariance to analyse the interaction between the two CC/kg groups and the two OF groups on nutrition intake. The secondary outcome is to use multiple regression analysis to investigate the nutrients significantly related to CC/kg when stratified by OF, with age, sex, body mass index, drinking status, smoking status and regular exercise as input covariates.

RESULTS

A two-way analysis of covariance revealed a significant interaction between the two CC/kg groups and the two OF groups on animal protein intake (p=0.039). Multiple comparisons using the Bonferroni analysis revealed a significantly lower animal protein intake in the OF group than in the non-OF group with a low CC/kg (p=0.033) but not in the group with a high CC/kg. The multiple regression analysis stratified by OF revealed a positive correlation between animal protein intake and CC/kg (p=0.002).

CONCLUSIONS

The present results revealed a significantly lower animal protein intake in the OF group than in the non-OF group in the low-CC/kg group, but no such difference was observed in the high-CC/kg group. Further longitudinal studies are needed to elucidate this relationship.

Association between dietary knowledge and muscle mass in Chinese older adults: a cross-sectional and longitudinal study

OBJECTIVES

This study aims to explore the possible association between dietary knowledge and muscle mass in a Chinese population aged 60 years and above.

DESIGN

Cross-sectional and longitudinal studies.

SETTING

Data from the 2006 and 2011 China Health and Nutrition Survey (CHNS) were used for this study.

PARTICIPANTS

A total of 1487 Chinese participants (44.38% males) aged 60 and above in the 2006 survey were included in the cross-sectional study. From the same study population, a total of 1023 participants (46.82% males) with normal muscle mass on the interview date of 2006 were included in the longitudinal study.

OUTCOME MEASURES

Dietary knowledge was accessed by a validated CHNS questionnaire. Appendicular skeletal muscle mass was calculated using a validated anthropometric equation derived from a representative Chinese population. Based on the 2021 Chinese consensus on sarcopenia, the appendicular skeletal muscle mass was categorised as 'normal' or 'low' using sex-specific cut-off values.

RESULTS

The prevalence of low muscle mass in the study population was 31.20%, with a higher prevalence in females (34.22%). People with low muscle mass have a significantly lower dietary knowledge score (mean difference: -1.74, 95% CI -2.20 to -1.29). In the cross-sectional analysis, one score higher in dietary knowledge score was associated with a 4% lower odds of low muscle mass (OR=0.96, 95% CI 0.93 to 0.99). Compared with people in the lowest quartile of dietary knowledge, people in the highest quartile have a 44% lower odds of low muscle mass (OR=0.56, 95% CI 0.35 to 0.91). In the longitudinal analysis, no significant association was found between dietary knowledge and low muscle mass, yet the upper 95% CI was close to one (HR=0.97, 95% CI 0.93 to 1.01).

CONCLUSIONS

Sufficient dietary knowledge may play a protective role in maintaining normal muscle mass in Chinese adults aged 60 or above.

Optimizing clinical nutrition research: the role of adaptive and pragmatic trials

Evidence-based nutritional recommendations address the health impact of suboptimal nutritional status. Efficacy randomized controlled trials (RCTs) have traditionally been the preferred method for determining the effects of nutritional interventions on health outcomes. Nevertheless, obtaining a holistic understanding of intervention efficacy and effectiveness in real-world settings is stymied by inherent constraints of efficacy RCTs. These limitations are further compounded by the complexity of nutritional interventions and the intricacies of the clinical context. Herein, we explore the advantages and limitations of alternative study designs (e.g., adaptive and pragmatic trials), which can be incorporated into RCTs to optimize the efficacy or effectiveness of interventions in clinical nutrition research. Efficacy RCTs often lack external validity due to their fixed design and restrictive eligibility criteria, leading to efficacy-effectiveness and evidence-practice gaps. Adaptive trials improve the evaluation of nutritional intervention efficacy through planned study modifications, such as recalculating sample sizes or discontinuing a study arm. Pragmatic trials are embedded within clinical practice or conducted in settings that resemble standard of care, enabling a more comprehensive assessment of intervention effectiveness. Pragmatic trials often rely on patient-oriented primary outcomes, acquire outcome data from electronic health records, and employ broader eligibility criteria. Consequently, adaptive and pragmatic trials facilitate the prompt implementation of evidence-based nutritional recommendations into clinical practice. Recognizing the limitations of efficacy RCTs and the potential advantages of alternative trial designs is essential for bridging efficacy-effectiveness and evidence-practice gaps. Ultimately, this awareness will lead to a greater number of patients benefiting from evidence-based nutritional recommendations.

What are the most effective exercise, physical activity and dietary interventions to improve body composition in women diagnosed with or at high-risk of breast cancer? A systematic review and network meta-analysis

BACKGROUND

Obesity has been recognized as a risk factor in the development and recurrence of breast cancer and is also associated with poor prognostic outcomes. This systematic review and network meta-analysis aimed to identify the most effective exercise, physical activity, and dietary interventions to reduce fat mass, body fat percentage and body weight as well as potentially increase lean mass in women diagnosed with or at high risk of breast cancer.

METHODS

A systematic search of databases was performed up to May 2022. Eligible randomized controlled trials examined the effects of exercise, physical activity and/or dietary interventions on fat mass and lean mass in women diagnosed with or at high risk of breast cancer. A random-effects network meta-analysis was conducted to determine the effects of different interventions across outcomes when sufficient studies were available.

RESULTS

Eighty-four studies (n = 6428) were included in this review. Caloric restriction and combined exercise + caloric restriction significantly reduced fat mass (range, -3.9 to -3.7 kg) and body weight (range, -5.3 to -4.7 kg), whereas physical activity + caloric restriction significantly reduced body fat percentage (-2.4%; 95% confidence interval [CI], -3.4% to -13%) and body mass index (-2.2 kg × m-2 ; 95% CI, -3.0 to -1.4 kg × m-2 ) in breast cancer patients. Resistance exercise was the most effective intervention to increase lean mass (0.7 kg; 95% CI, 0.5-1.0 kg) in breast cancer patients.

CONCLUSION

Multimodal exercise and diet programs were the most effective interventions to reduce fat mass, body fat percentage, and body weight and increase and/or preserve lean mass.

A single bout of prior resistance exercise attenuates muscle atrophy and declines in myofibrillar protein synthesis during bed-rest in older men

Impairments in myofibrillar protein synthesis (MyoPS) during bed rest accelerate skeletal muscle loss in older adults, increasing the risk of adverse secondary health outcomes. We investigated the effect of prior resistance exercise (RE) on MyoPS and muscle morphology during a disuse event in 10 healthy older men (65-80 years). Participants completed a single bout of unilateral leg RE the evening prior to 5 days of in-patient bed-rest. Quadriceps cross-sectional area (CSA) was determined prior to and following bed-rest. Serial muscle biopsies and dual stable isotope tracers were used to determine rates of integrated MyoPS (iMyoPS) over a 7 day habitual 'free-living' phase and the bed-rest phase, and rates of acute postabsorptive and postprandial MyoPS (aMyoPS) at the end of bed rest. Quadriceps CSA at 40%, 60% and 80% of muscle length significantly decreased in exercised (EX) and non-exercised control (CTL) legs with bed-rest. The decline in quadriceps CSA at 40% and 60% of muscle length was attenuated in EX compared with CTL. During bed-rest, iMyoPS rates decreased from habitual values in CTL, but not EX, and were significantly different between legs. Postprandial aMyoPS rates increased above postabsorptive values in EX only. The change in iMyoPS over bed-rest correlated with the change in quadriceps CSA in CTL, but not EX. A single bout of RE attenuated the decline in iMyoPS rates and quadriceps atrophy with 5 days of bed-rest in older men. Further work is required to understand the functional and clinical implications of prior RE in older patient populations. KEY POINTS: Age-related skeletal muscle deterioration, linked to numerous adverse health outcomes, is driven by impairments in muscle protein synthesis that are accelerated during periods of disuse. Resistance exercise can stimulate muscle protein synthesis over several days of recovery and therefore could counteract impairments in this process that occur in the early phase of disuse. In the present study, we demonstrate that the decline in myofibrillar protein synthesis and muscle atrophy over 5 days of bed-rest in older men was attenuated by a single bout of unilateral resistance exercise performed the evening prior to bed-rest. These findings suggest that concise resistance exercise intervention holds the potential to support muscle mass retention in older individuals during short-term disuse, with implications for delaying sarcopenia progression in ageing populations.

Dynapenia and Sarcopenia in Post-COVID-19 Syndrome Hospitalized Patients Are Associated with Severe Reduction in Pulmonary Function

BACKGROUND

After hospital discharge, post-COVID-19 syndrome has been observed to be associated with impaired diffusing capacity, respiratory muscle strength, and lung imaging abnormalities, in addition to loss of muscle mass/strength, sarcopenia, and obesity impact exercise tolerance, pulmonary functions, and overall prognosis. However, the relationship between lung function and the coexistence of obesity with low muscle strength and sarcopenia in post-COVID-19 patients remains poorly investigated. Therefore, our aim was to evaluate the association between lung function and the coexistence of obesity with dynapenia and sarcopenia in post-COVID-19 syndrome patients.

METHODS

This cross-sectional study included subjects who were hospitalized due to moderate to severe COVID-19, as confirmed by PCR testing. Subjects who could not be contacted, declined to participate, or died before the follow-up visit were excluded.

RESULTS

A total of 711 subjects were evaluated; the mean age was 53.64 ± 13.57 years, 12.4% had normal weight, 12.6% were dynapenic without obesity, 8.3% had sarcopenia, 41.6% had obesity, 21.2% had dynapenic obesity, and 3.8% had sarcopenic obesity. In terms of pulmonary function, the dynapenic subjects showed decreases of -3.45% in FEV1, -12.61 cmH2O in MIP, and -12.85 cmH2O in MEP. On the other hand, the sarcopenic subjects showed decreases of -6.14 cmH2O in MIP and -11.64 cmH2O in MEP. The dynapenic obesity group displayed a reduction of -12.13% in PEF.

CONCLUSIONS

In post-COVID-19 syndrome, dynapenia and sarcopenia-both with and without obesity-have been associated with lower lung function.

Prediction equations to estimate muscle mass using anthropometric data: a systematic review

CONTEXT

Reduced muscle mass is linked to poor outcomes in both inpatients and outpatients, highlighting the importance of muscle mass assessment in clinical practice. However, laboratory methods to assess muscle mass are not yet feasible for routine use in clinical practice because of limited availability and high costs.

OBJECTIVE

This work aims to review the literature on muscle mass prediction by anthropometric equations in adults or older people.

DATA SOURCES

The following databases were searched for observational studies published until June 2022: MEDLINE, Embase, Scopus, SPORTDiscus, and Web of Science.

DATA EXTRACTION

Of 6437 articles initially identified, 63 met the inclusion criteria for this review. Four independent reviewers, working in pairs, selected and extracted data from those articles.

DATA ANALYSIS

Two studies reported new equations for prediction of skeletal muscle mass: 10 equations for free-fat mass and lean soft tissue, 22 for appendicular lean mass, 7 for upper-body muscle mass, and 7 for lower-body muscle mass. Twenty-one studies validated previously proposed equations. This systematic review shows there are numerous equations in the literature for muscle mass prediction, and most are validated for healthy adults. However, many equations were not always accurate and validated in all groups, especially people with obesity, undernourished people, and older people. Moreover, in some studies, it was unclear if fat-free mass or lean soft tissue had been assessed because of an imprecise description of muscle mass terminology.

CONCLUSION

This systematic review identified several feasible, practical, and low-cost equations for muscle mass prediction, some of which have excellent accuracy in healthy adults, older people, women, and athletes. Malnourished individuals and people with obesity were understudied in the literature, as were older people, for whom there are only equations for appendicular lean mass.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021257200.

Estimation of 24-hour urinary creatinine excretion from patient variables: A novel approach to identify patients with low muscle mass and malnutrition and relationship to outcomes

BACKGROUND

Low muscle mass has been correlated with adverse outcomes in patients who are critically ill. Methods to identify low muscularity such as computed tomography scans or bioelectrical impedance analyses are impractical for admission screening. Urinary creatinine excretion (UCE) and creatinine height index (CHI) are associated with muscularity and outcomes but require a 24-h urine collection. The estimation of UCE from patient variables avoids the need for a 24-h urine collection and may be clinically useful.

METHODS

Variables of age, height, weight, sex, plasma creatinine, blood urea nitrogen (BUN), glucose, sodium, potassium, chloride, and carbon dioxide from a deidentified data set of 967 patients who had UCE measured were used to develop models to predict UCE. The model identified with the best predictive ability was validated and then retrospectively applied to a separate sample of 120 veterans who were critically ill to examine if UCE and CHI predicted malnutrition or were associated with outcomes.

RESULTS

A model was identified that included variables of plasma creatinine, BUN, age, and weight and was found to be highly correlated, moderately predictive of UCE, and statistically significant. Patients with model-estimated CHI  ≤  60% had significantly lower body weight, body mass index, plasma creatinine, and sera albumin and prealbumin levels; were 8.0 times more likely to be diagnosed with malnutrition; and were 2.6 times more likely to be readmitted in 6 months.

CONCLUSION

A model that predicts UCE offers a novel method to identify patients with low muscularity and malnutrition on admission without the use of invasive tests.

U-shaped association between body mass index and health-related quality of life impairment in Korean cancer survivors: a nationwide representative cross-sectional survey

PURPOSE

Although obesity is an important risk factor for cancer incidence, the effect of body mass index (BMI) on health-related quality of life (HRQoL) after cancer treatment remains unknown. This population-based cross-sectional study assessed different levels of BMI as an important factor associated with impaired HRQoL in long-term cancer survivors.

METHODS

The study enrolled 1104 cancer survivors from the fourth to seventh Korea National Health and Nutrition Examination Surveys (KNHANES 2007-2018) who were alive at least 5 years after their cancer diagnoses. The BMI was classified into four categories: < 20 (underweight), 20-22.9 (healthy weight), 23-24.9 (overweight), and ≥ 25 kg/m2 (obese). Impaired HRQoL was defined as the lowest quartile of European Quality of Life 5-Dimensions (EQ-5D) questionnaire scores.

RESULTS

Cancer survivors who were underweight or obese were more likely to report health problems on each dimension of the EQ-5D compared to the other BMI groups. In multivariate logistic regression analysis, the two extreme BMI categories were significantly associated with impaired HRQoL (BMI < 20 kg/m2: odds ratio [OR] = 1.73, 95% confidence interval [CI] = 1.08-2.86; BMI ≥ 25 kg/m2: OR = 2.14, 95% CI = 1.41-3.25; P trend = 0.049), especially in the gastrointestinal cancer group (P heterogeneity = 0.007). Moreover, the association between underweight/obese and impaired HRQoL showed a significant sex difference (P heterogeneity = 0.019).

CONCLUSIONS

The results of this study suggest that deviations from normal BMI, such as being underweight or obese, are negatively associated with HRQoL in long-term cancer survivors; to some extent, this may depend on cancer type and sex.

IMPLICATIONS FOR CANCER SURVIVORS

Reaching or maintaining a healthy weight should be emphasized for cancer survivors as a long-term goal even after cancer treatment.

Long-term clinical outcomes in critically ill patients with sepsis and pre-existing low muscle mass: a retrospective cohort study

PURPOSE

Critically ill patients with sepsis account for significant disease morbidity and healthcare costs. Low muscle mass has been proposed as an independent risk factor for poor short-term outcomes, although its effect on long-term outcomes remains unclear.

METHODS

Retrospective cohort analysis of patients treated at a quaternary care medical center over 6 years (09/2014 - 12/2020). Critically ill patients meeting Sepsis-3 criteria were included, with low muscle mass defined by [Formula: see text] 5th percentile skeletal muscle index, measured at the L3 lumbar level (L3SMI) on Computed-Tomography (CT) scan ([Formula: see text] 41.6 cm2/m2 for males and [Formula: see text] 32.0 cm2/m2 for females). L3SMI was calculated by normalizing the CT-measured skeletal muscle area to the square of the patient's height (in meters). Measurements were taken from abdominal/pelvic CT scan obtained within 7 days of sepsis onset. The prevalence of low muscle mass and its association with clinical outcomes, including in-hospital and one-year mortality, and post-hospitalization discharge disposition in survivors, was analyzed. Unfavorable post-hospitalization disposition was defined as discharge to a location other than the patient's home.

RESULTS

Low muscle mass was present in 34 (23%) of 150 patients, with mean skeletal muscle indices of 28.0 ± 2.9 cm2/m2 and 36.8 ± 3.3 cm2/m2 in females and males, respectively. While low muscle mass was not a significant risk factor for in-hospital mortality (hazard ratio 1.33; 95% CI 0.64 - 2.76; p = 0.437), it significantly increased one-year mortality after adjusting for age and illness severity using Cox multivariate regression (hazard ratio 1.9; 95% CI 1.1 - 3.2; p = 0.014). Unfavorable post-hospitalization discharge disposition was not associated with low muscle mass, after adjusting for age and illness severity in a single, multivariate model.

CONCLUSION

Low muscle mass independently predicts one-year mortality but is not associated with in-hospital mortality or unfavorable hospital discharge disposition in critically ill patients with sepsis.

Sustained increase in physical fitness independently predicts improvements in cardiometabolic risk profile in type 2 diabetes

AIMS

To investigate the relationship between changes in physical fitness and cardiovascular risk factors and scores in patients with type 2 diabetes receiving either a behavioural counselling intervention to increase moderate-to-vigorous-intensity physical activity (MVPA) and decrease sedentary-time (SED-time) or standard care.

MATERIALS AND METHODS

This is a pre-specified ancillary analysis of the Italian Diabetes and Exercise Study_2, a 3-year randomized clinical trial in which 300 physically inactive and sedentary patients were randomized 1:1 to receive either a one-month theoretical and practical counselling each year or standard care. Mean changes from baseline throughout the 3-year period in MVPA, SED-time, cardiorespiratory fitness (VO2max ), muscle strength, flexibility, cardiovascular risk factors and scores were calculated for study completers (n = 267) and considered irrespective of study arm.

RESULTS

Haemoglobin (Hb) A1c and coronary heart disease (CHD) risk scores decreased with quartiles of VO2max and lower body muscle strength changes. Multivariable linear regression analysis showed that increases in VO2max independently predicted decreases in HbA1c , blood glucose, diastolic blood pressure (BP), CHD and total stroke 10-year risk and increases in HDL cholesterol, whereas increases in lower body muscle strength independently predicted decreases in body mass index (BMI), waist circumference, triglycerides, systolic BP, CHD and fatal stroke 10-year risk. These associations remained after including changes in BMI, waist circumference, fat mass and fat-free mass, or MVPA and SED-time as covariates.

CONCLUSIONS

Improvement in physical fitness predicts favourable changes in cardiometabolic risk profile, independent of changes not only in (central) adiposity or body composition but also in MVPA and SED-time.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT01600937; URL https://clinicaltrials.gov/ct2/show/NCT01600937.

Estimation of skeletal muscle mass in 4-year-old children using the D3-creatine dilution method

BACKGROUND

Given limited experience in applying the creatine-(methyl-D3) (D3Cr) dilution method to measure skeletal muscle mass (SMM) in young children, the feasibility of deployment in a fielding setting and performance of the method was assessed in a cohort of 4-year-old children in Dhaka, Bangladesh.

METHODS

Following D3Cr oral dose (10 mg) administration, single fasting urine samples were collected at 2-4 days (n = 100). Twenty-four-hour post-dose collections and serial spot urine samples on days 2, 3 and 4 were obtained in a subset of participants (n = 10). Urinary creatine, creatinine, D3Cr and D3-creatinine enrichment were analyzed by liquid chromatography-tandem mass spectrometry. Appendicular lean mass (ALM) was measured by dual-energy x-ray absorptiometry and grip strength was measured by a hand-held dynamometer.

RESULTS

SMM was measured successfully in 91% of participants, and there were no adverse events. Mean ± SD SMM was greater than ALM (4.5 ± 0.4 and 3.2 ± 0.6 kg, respectively). Precision of SMM was low (intraclass correlation = 0.20; 95% CI: 0.02, 0.75; n = 10). Grip strength was not associated with SMM in multivariable analysis (0.004 kg per 100 g of SMM; 95% CI: -0.031, 0.038; n = 91).

CONCLUSIONS

The D3Cr dilution method was feasible in a community setting. However, high within-child variability in SMM estimates suggests the need for further optimization of this approach.

IMPACT

The D3-creatine (D3Cr) stable isotope dilution method was considered a feasible method for the estimation of skeletal muscle mass (SMM) in young children in a community setting and was well accepted among participants. SMM was weakly associated with both dual-energy x-ray absorptiometry-derived values of appendicular lean mass and grip strength. High within-child variability in estimated values of SMM suggests that further optimization of the D3Cr stable isotope dilution method is required prior to implementation in community research settings.

Short-Term Effects of Dietary Protein Supplementation on Physical Recovery in Older Patients at Risk of Malnutrition during Inpatient Rehabilitation: A Pilot, Randomized, Controlled Trial

It is estimated that about 50% of geriatric rehabilitation patients suffer from sarcopenia. Thereby, malnutrition is frequently associated with sarcopenia, and dietary intake is the main modifiable risk factor. During hospitalization, older adults are recommended to consume more dietary protein than the current recommended dietary allowance of 0.8 g/kg body weight per day to optimize the recovery of muscular strength and physical function. This prospective pilot study examined the feasibility and preliminary efficacy of short-term protein supplementation with protein-enriched foods and drinks on the hand-grip strength, nutritional status, and physical function of older patients at risk of malnutrition during a three-week inpatient orthopedic rehabilitation stay. The Mini Nutritional Assessment (MNA) tool was used to assess malnutrition. Patients with an MNA score ≤ 23.5 points were randomly assigned to an intervention group (goal: to consume 1.2-1.5 g protein/kg body weight per day) or a control group (standard care). Both groups carried out the same rehabilitation program. Physical recovery parameters were determined at admission and discharge. A trend was recognized for participants in the intervention group to consume more protein than the control group (p = 0.058): 95.3 (SD 13.2) g/day as compared to 77.2 (SD 24.2) g/day, which corresponds to a mean protein intake of 1.6 (SD 0.3) g/kg/day vs. 1.3 (SD 0.5) g/kg/day. Dietary protein supplementation increased body weight by an average of 0.9 (SD 1.1) kg and fat mass by an average of 0.9 (SD 1.2) kg as compared to the baseline (p = 0.039 and p = 0.050, respectively). No significant change in hand-grip strength, body composition, or physical function was observed. In conclusion, short-term intervention with protein-enriched foods and drinks enabled older patients at risk of malnutrition to increase their protein intake to levels that are higher than their required intake. In these older individuals with appropriate protein intake, dietary protein supplementation did not result in a greater improvement in physical recovery outcomes during short-term inpatient rehabilitation. The intervention improved dietary protein intake, but further research (e.g., a full-scale, randomized, controlled trial with sufficient power) is required to determine the effects on physical function outcomes.

Growth trajectories during infancy have a significant impact on body composition in childhood

Evidence supports that growth trajectory during infancy has a major impact on body composition. We aimed to examine body composition in children born small for gestational age (SGA) or appropriate for gestational age (AGA) adjusted for postnatal growth velocity. We enrolled 365 children, 75 SGA and 290 AGA, aged 7 to 10 years, examining anthropometrics, skinfold thickness, and body composition using bioelectrical impedance analysis. Growth velocity was defined as rapid or slow (weight gain > or <0.67 z-scores, respectively). Gestational age, sex, delivery mode, gestational diabetes, hypertension, nutrition, exercise, parental body mass index (BMI), and socioeconomic status were considered. At a mean of 9 years of age, SGA compared with AGA-born children, had significantly lower lean mass. BMI was negatively associated with SGA status (beta = 0.80, P = .046), after adjusting for birth weight, delivery mode, and breastfeeding. The lean mass index was negatively associated with SGA status (beta = 0.39, P = .018), after adjusting for the same factors. SGA-born participants with slow growth velocity had significantly lower lean mass in comparison to AGA-born counterparts. SGA-born children with rapid compared with those with slow growth velocity had significantly higher absolute fat mass. BMI was negatively associated with a slow postnatal growth pattern (beta = 0.59, P = .023), and the lean mass index was negatively associated with a slow postnatal growth pattern (beta = 0.78, P = .006), after adjusting for the same factors. In conclusion, SGA-born children presented a lower lean mass in comparison to AGA-born counterparts, whereas BMI and lean mass index were negatively associated with slow postnatal growth velocity.

AI-based CT Body Composition Identifies Myosteatosis as Key Mortality Predictor in Asymptomatic Adults

Background Body composition data have been limited to adults with disease or older age. The prognostic impact in otherwise asymptomatic adults is unclear. Purpose To use artificial intelligence-based body composition metrics from routine abdominal CT scans in asymptomatic adults to clarify the association between obesity, liver steatosis, myopenia, and myosteatosis and the risk of mortality. Materials and Methods In this retrospective single-center study, consecutive adult outpatients undergoing routine colorectal cancer screening from April 2004 to December 2016 were included. Using a U-Net algorithm, the following body composition metrics were extracted from low-dose, noncontrast, supine multidetector abdominal CT scans: total muscle area, muscle density, subcutaneous and visceral fat area, and volumetric liver density. Abnormal body composition was defined by the presence of liver steatosis, obesity, muscle fatty infiltration (myosteatosis), and/or low muscle mass (myopenia). The incidence of death and major adverse cardiovascular events were recorded during a median follow-up of 8.8 years. Multivariable analyses were performed accounting for age, sex, smoking status, myosteatosis, liver steatosis, myopenia, type 2 diabetes, obesity, visceral fat, and history of cardiovascular events. Results Overall, 8982 consecutive outpatients (mean age, 57 years ± 8 [SD]; 5008 female, 3974 male) were included. Abnormal body composition was found in 86% (434 of 507) of patients who died during follow-up. Myosteatosis was found in 278 of 507 patients (55%) who died (15.5% absolute risk at 10 years). Myosteatosis, obesity, liver steatosis, and myopenia were associated with increased mortality risk (hazard ratio [HR]: 4.33 [95% CI: 3.63, 5.16], 1.27 [95% CI: 1.06, 1.53], 1.86 [95% CI: 1.56, 2.21], and 1.75 [95% CI: 1.43, 2.14], respectively). In 8303 patients (excluding 679 patients without complete data), after multivariable adjustment, myosteatosis remained associated with increased mortality risk (HR, 1.89 [95% CI: 1.52, 2.35]; P < .001). Conclusion Artificial intelligence-based profiling of body composition from routine abdominal CT scans identified myosteatosis as a key predictor of mortality risk in asymptomatic adults. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tong and Magudia in this issue.

Association between thoracic and third lumbar CT-derived muscle mass and density in Caucasian patients without chronic disease: a proof-of-concept study

BACKGROUND

Computed tomography (CT) is increasingly used in the clinical workup, and existing scan contains unused body composition data, potentially useful in a clinical setting. However, there is no healthy reference for contrast-enhanced thoracic CT-derived muscle measures. Therefore, we aimed at investigating whether there is a correlation between each of the thoracic and third lumbar vertebra level (L3) skeletal muscle area (SMA), skeletal muscle index (SMI), and skeletal muscle density (SMD) at contrast-enhanced CT in patients without chronic disease.

METHODS

A proof-of-concept retrospective observational study was based on Caucasian patients without chronic disease, who received CT for trauma between 2012 and 2014. Muscle measures were assessed using a semiautomated threshold-based software by two raters independently. Pearson's correlation between each thoracic level and third lumbar and intraclass correlation between two raters and test-retest with SMA as proxy parameters were used.

RESULTS

Twenty-one patients (11 males, 10 females; median age 29 years) were included. The second thoracic vertebra (T2) had the highest median of cumulated SMA (males 314.7 cm², females 118.5 cm²) and SMI (97.8 cm²/m² and 70.4 cm²/m², respectively). The strongest SMA correlation was observed between T5 and L3 (r = 0.970), the SMI between T11 and L3 (r = 0.938), and the SMD between the T10 and L3 (r = 0.890).

CONCLUSIONS

This study suggests that any of the thoracic levels can be valid to assess skeletal muscle mass. However, the T5 may be most favourable for measuring SMA, the T11 for SMI, and T10 for SMD when using contrast-enhanced thoracic CT.

RELEVANCE STATEMENT

In COPD patients, a CT-derived thoracic muscle mass assessment may help identify who would benefit from focused pulmonary rehabilitation: thoracic contrast-enhanced CT conducted as part of the standard clinical workup can be used for this evaluation.

KEY POINTS

• Any thoracic level can be used to assess thoracic muscle mass. • Thoracic level 5 is strongly associated with the 3rd lumbar muscle area. • A strong correlation between the thoracic level 11 and the 3rd lumbar muscle index. • Thoracic level 10 is strongly associated with the 3rd lumbar muscle density.

Association of muscle wasting with mortality risk among adults: A systematic review and meta-analysis of prospective studies

The relationship between muscle wasting and mortality risk in the general population remains unclear. Our study was conducted to examine and quantify the associations between muscle wasting and all-cause and cause-specific mortality risks. PubMed, Web of Science and Cochrane Library were searched until 22 March 2023 for main data sources and references of retrieved relevant articles. Prospective studies investigating the associations of muscle wasting with risks of all-cause and cause-specific mortality in the general population were eligible. A random-effect model was used to calculate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the lowest versus normal categories of muscle mass. Subgroup analyses and meta-regression were performed to investigate the potential sources of heterogeneities among studies. Dose-response analyses were conducted to evaluate the relationship between muscle mass and mortality risk. Forty-nine prospective studies were included in the meta-analysis. A total of 61 055 deaths were ascertained among 878 349 participants during the 2.5- to 32-year follow-up. Muscle wasting was associated with higher mortality risks of all causes (RR = 1.36, 95% CI, 1.28 to 1.44, I²  = 94.9%, 49 studies), cardiovascular disease (CVD) (RR = 1.29, 95% CI, 1.05 to 1.58, I²  = 88.1%, 8 studies), cancer (RR = 1.14, 95% CI, 1.02 to 1.27, I²  = 38.7%, 3 studies) and respiratory disease (RR = 1.36, 95% CI, 1.11 to 1.67, I²  = 62.8%, 3 studies). Subgroup analyses revealed that muscle wasting, regardless of muscle strength, was significantly associated with a higher all-cause mortality risk. Meta-regression showed that risks of muscle wasting-related all-cause mortality (P = 0.06) and CVD mortality (P = 0.09) were lower in studies with longer follow-ups. An approximately inverse linear dose-response relationship was observed between mid-arm muscle circumference and all-cause mortality risk (P < 0.01 for non-linearity). Muscle wasting was associated with higher mortality risks of all causes, CVD, cancer and respiratory disease in the general population. Early detection and treatment for muscle wasting might be crucial for reducing mortality risk and promoting healthy longevity.

Relationship between sarcopenia and cachexia with prognostic markers of middle-aged and older inpatients with COVID-19: a case-control study

PURPOSE

SARS-CoV-2 infection can lead to various manifestations beyond an inflammatory response, such as anorexia, hyposmia, and other symptoms that may increase the risk of nutritional disorders. Sarcopenia and cachexia are conditions that appear to influence COVID-19 evolution. Thus, this study aimed to evaluate sarcopenia and cachexia in hospitalized patients with COVID-19, verifying their clinical impacts and relationship with prognostic markers.

METHODS

This is a case-control study involving inpatients with and without a COVID-19 diagnosis. The occurrence of sarcopenia was evaluated according to European Working Group on Sarcopenia 2 criteria. Cachexia was evaluated according to (Evans et al. in Clin Nutr 27:793-799, 2008) criteria. Inflammatory markers and the 4C Mortality Score were evaluated.

RESULTS

Our study included 96 individuals, divided into two groups: COVID-19 (n = 32) and control (n = 64). The mean age of the COVID-19 group was 63.3 ± 11.8 years, and the control group had a mean age of 64.3 ± 5.5 years. No significant differences in mean age were found between the groups. The prevalence of sarcopenia and cachexia in patients with COVID-19 was 21.9% and 28.1%, respectively, while in the control group, it was 29.7% and 26.6%, respectively. Sarcopenic patients with COVID-19 had a higher risk of death (4C Mortality Score) (p = 0.038). The occurrence of sarcopenia or cachexia within the COVID-19 group was not associated with inflammatory biomarkers or a higher number of COVID-19 symptoms (p > 0.05).

CONCLUSION

The presence of sarcopenia among COVID-19 patients increased the risk of mortality.

Assessment of Balance Parameters in Children with Weakened Axial Muscle Tone Undergoing Sensory Integration Therapy

Children with weakened axial muscle tone face various problems every day. One is maintaining a stable body posture, which limits their participation in activities and games with peers. The study aimed to assess balance parameters in children with weakened axial muscle tone who underwent sensory integration therapy (SI). The study group consisted of 21 children (divided into three age groups) referred by a doctor for therapy.

METHODS

The ZEBRIS platform was used to measure the balance parameters (MCoCx, MCoCy, SPL, WoE, HoE, and AoE). The study was conducted twice: before and after two months of sensory integration therapy. The results were compiled using the TIBICO^® Statistica software version 13.3.0.

RESULTS

After the SI program, statistically significant changes were observed in the values of MCoCy_oe, WoE_oe, AoE_oe in the group of four-year-olds, MCoCX_ce in the group of five-year-olds, and in SPL_ce and AoE_ce in six-year-olds. A statistically significant, highly positive correlation was observed between body height and changes in SPL_oe, HoE_oe, and AoE_oe in the group of six-year-olds, as well as in the case of changes in SPL_oe in the group of five-year-olds. In the group of four-year-olds, a statistically significant correlation occurred only between body height and the change in the MCoCx_oe value.

CONCLUSIONS

the sensory integration therapy used in the study group of 4-6-year-old children with reduced muscle tone gave positive results in the form of improved static balance and balance.

Influence of fat-free mass index on the survival of patients with head and neck cancer

PURPOSE

To determine whether muscle mass, defined by fat-free mass index (FFMI) measured with bioelectrical impedance analysis (BIA), is predictive of survival of head and neck squamous cell carcinoma (HNSCC) patients.

METHODS

HNSCC patients treated between 2014 and 2018 at the Department for Nutrition of the Institute of Oncology Ljubljana were reviewed. The FFMI values from the pretreatment BIA measurements and pretreatment body mass index (BMI) were used to categorize patients into groups with low and normal muscle mass and BMI using the Global Leadership Initiative on malnutrition (GLIM) recommended cutoff values. The impact of FFMI on disease-free survival (DFS) and overall survival (OS) was determined.

RESULTS

Of the 71 included patients, 31 (43.7%) had normal FFMI, and 40 (56.3%) had low FFMI, whereas 44 (62%) and 27 (38%) of the patients had normal and low BMI, respectively. Between FFMI and BMI values, a significant correlation was found (R_P = 0.75, p < 0.001). Univariate regression analysis showed that FFMI (as a continuous variable) was of prognostic significance for OS (p = 0.039), which was confirmed by multivariate regression analysis (p = 0.029). The model where BMI replaced FFMI negated the prognostic value of BMI (as a continuous variable). Neither FFMI nor BMI was found to be a predictor of DFS on univariate or multivariate analysis.

CONCLUSIONS

In the present group of HNSCC patients, low FFMI adversely influenced OS, emphasizing the importance of using body composition measurement over BMI alone for pretreatment nutritional evaluation of these patients.

Effect of exercise modality and weight loss on changes in muscle and bone quality in older adults with obesity

BACKGROUND

Little is known about the effect of exercise modality during a dietary weight loss program on muscle size and quality, as measured by computed tomography (CT). Even less is known about how CT-derived changes in muscle track with changes in volumetric bone mineral density (vBMD) and bone strength.

METHODS

Older adults (66 ± 5 years, 64 % women) were randomized to 18-months of diet-induced weight loss (WL), WL with aerobic training (WL + AT), or WL with resistance training (WL + RT). CT-derived muscle area, radio-attenuation and intermuscular fat percentage at the trunk and mid-thigh were determined at baseline (n = 55) and 18-month follow-up (n = 22-34), and changes were adjusted for sex, baseline value, and weight lost. Lumbar spine and hip vBMD and finite element-derived bone strength were also measured.

RESULTS

After adjustment for the weight lost, muscle area losses at the trunk were -7.82 cm2 [-12.30, -3.35] for WL, -7.72 cm2 [-11.36, -4.07] for WL + AT, and -5.14 cm2 [-8.65, -1.63] for WL + RT (p < 0.001 for group differences). At the mid-thigh, decreases were -6.20 cm2 [-10.39, -2.02] for WL, -7.84 cm2 [-11.19, -4.48] for WL + AT, and -0.60 cm2 [-4.14, 2.94] for WL + RT; this difference between WL + AT and WL + RT was significant in post-hoc testing (p = 0.01). Change in trunk muscle radio-attenuation was positively associated with change in lumbar bone strength (r = 0.41, p = 0.04).

CONCLUSIONS

WL + RT better preserved muscle area and improved muscle quality more consistently than WL + AT or WL alone. More research is needed to characterize the associations between muscle and bone quality in older adults undertaking weight loss interventions.

The Impact of Body Mass Composition on Outcome in Multiple Traumatized Patients—Results from the Fourth Thoracic and Third Lumbar Vertebrae: A Single-Center Retrospective Observational Study

Background: Body mass composition (BC) was shown to correlate with outcome in patients after surgery and minor trauma. As BC is assessed using computed tomography (CT) and routinely applied in multiple trauma (MT), this study will help to analyze whether BC variables also correlate with outcome in trauma patients. Materials and Methods: Inclusion criteria were MT (Injury Severity Score (ISS) > 15) and whole-body CT (WBCT) scan on admission. Muscle and fat tissue were assessed at the level of the fourth thoracic vertebra (T4) and the third lumbar vertebra (L3) using Slice-O-matic software, version 5.0 (Tomovision, Montreal, QC, Canada). Univariate and multivariate regression models were used with regard to outcome parameters such as duration of ventilation, hospital stay, local (i.e., pneumonia, wound infection) and systemic (i.e., MODS, SIRS) complications, and mortality. Results: 297 patients were included. BC correlated with both the development and severity of complications. Skeletal muscle index (SMI) and subcutaneous adipose tissue index (SATI) at both T4 and L3 correlated positively with the occurrence of systemic infections. Local infections positively correlated with SMI at T4. Low muscle mass and high visceral adipose tissue (VAT) predicted the severity of systemic and local complications. Muscle tissue markers at both T4 and L3 predicted the severity of complications in roughly the same way. Moreover, higher muscle mass at the L3 level was significantly associated with higher overall survival, while SATI at the T4 level correlated positively with hospital stay, length of stay in the ICU, and duration of ventilation. Conclusions: A lower muscle mass and a high adipose tissue index are associated with a poor outcome in MT. For the first time, it was shown that BC at the fourth thoracic vertebra is associated with comparable results to those found at the third lumbar level.

Role of Machine Learning-Based CT Body Composition in Risk Prediction and Prognostication: Current State and Future Directions

CT body composition analysis has been shown to play an important role in predicting health and has the potential to improve patient outcomes if implemented clinically. Recent advances in artificial intelligence and machine learning have led to high speed and accuracy for extracting body composition metrics from CT scans. These may inform preoperative interventions and guide treatment planning. This review aims to discuss the clinical applications of CT body composition in clinical practice, as it moves towards widespread clinical implementation.

A Novel Creatinine Muscle Index Based on Creatinine Filtration: Associations with Frailty and Mortality

SIGNIFICANCE STATEMENT

Low muscle mass is related to frailty and increased mortality in older adults. However, muscle mass is not easily assessed in routine clinical practice. This paper describes a novel creatinine muscle index (CMI) on the basis of serum creatinine and cystatin C. CMI was moderately associated with frailty among older adults. A significantly higher proportion of individuals with weak grip strength were in the lowest tertile of CMI. The index was also associated with mortality. These results are consistent with the hypothesis that creatinine filtration may be an index of muscle mass, which may have utility in clinical practice.

BACKGROUND

Low muscle mass is related to frailty and increased mortality in older adults. However, muscle mass is not easily assessed in routine clinical practice.

METHODS

This study describes a novel creatinine muscle index (CMI) on the basis of serum creatinine and cystatin C in a community-based sample of older adults from the Atherosclerosis Risk in Communities Study. Analyses included 4639 participants who attended visit 5 (2011-2013) and 12,786 participants who attended visit 2 (1990-1992). CMI was defined as creatinine filtration (the product of serum creatinine times eGFR on the basis of cystatin C) and was analyzed in sex-specific tertiles. Cross-sectional associations of CMI with a frailty trichotomy, defined by the number (robust [0]/prefrail [1-2]/frail [3-5]) of five frailty components (weight loss, slowness, exhaustion, weakness, and low physical activity), were studied using polychotomous logistic regression and binary logistic regression with each frailty component. Cox regression was used to estimate associations of CMI at visit 5 and visit 2 with mortality. Models were adjusted for demographics, clinical variables, and comorbid conditions.

RESULTS

CMI (tertile 1 versus 3) was moderately associated with frailty (visit 5: adjusted odds ratio 4.23 [95% confidence interval (CI), 2.02 to 8.87] in men and 2.34 [95% CI, 1.41 to 3.89] in women) and with mortality (visit 5: adjusted hazard ratio 1.45 [95% CI, 1.08 to 1.94] in men and 1.55 [95% CI, 1.13 to 2.12] in women; similar results were seen at visit 2).

CONCLUSION

Lower CMI was associated with frailty and increased mortality, two clinical outcomes known to be associated with decreased muscle mass. Creatinine filtration may be an index of muscle mass and have utility in clinical practice, particularly at low levels.

Low muscle mass is associated with a higher risk of all-cause and cardiovascular disease-specific mortality in cancer survivors

OBJECTIVES

Individuals with prior cancer diagnosis are more likely to have low muscle mass (LMM) than their cancer-free counterparts. Understanding the effects of LMM on the prognosis of cancer survivors can be clinically important. The aim of this study was to investigate whether risks for all-cause and cardiovascular disease (CVD)-specific mortality differ by status of LMM in cancer survivors and a matched cohort without cancer history.

METHODS

We used cohort data from the 1999-2006 and 2011-2014 National Health and Nutrition Examination Survey. Participants included 946 adults surviving for ≥1 since cancer diagnosis and a matched cohort (by age, sex, and race) without cancer history (N = 1857). LMM was defined by appendicular lean mass and body height (men <7.26 kg/m2, women <5.45 kg/m2). Death was ascertained via the National Death Index and cause of death was assessed via International Classification of Diseases, Tenth Revision. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratio (aHR) and 95% confidence interval (CI) of LMM.

RESULTS

The mean age of cancer survivors and matched cohort was 60.6 y (SD 15) and 60.2 y (SD 14.9), respectively. The median follow-up was 10.5 y for survivors and 10.9 y for matched cohort. Overall, 22.2% of cancer survivors and 19.7% of the matched cohort had LMM, respectively. In all, 321 survivors (33.9%) and 495 participants (26.7%) in the matched cohort died during follow-up. CVD-specific deaths were identified in 58 survivors (6.1%) and 122 participants in the matched cohort (6.6%). The multivariable Cox model suggested that LMM was positively associated with all-cause (aHR, 1.73; 95% CI, 1.31-2.29) and CVD-specific (aHR, 2.13; 95% CI, 1.14-4.00) mortality in cancer survivors. The associations between LMM and risk for all-cause (aHR, 1.24; 95% CI, 0.98-1.56) and CVD-specific (aHR, 1.21; 95% CI, 0.75-1.93) mortality were not statistically significant in the matched cohort.

CONCLUSION

Cancer survivors with LMM have an increased risk for all-cause and CVD-specific mortality. This increase appears to be larger than that in counterparts without cancer history.

Effects of a Physical Exercise Programme through Service-Learning Methodology on Physical Activity, Physical Fitness and Perception of Physical Fitness and Health in University Students from Spain: A Preliminary Study

The practice of physical activity has been reported on countless occasions for the benefits it has on people's holistic health. However, today's society has high levels of inactivity and sedentary lifestyles, which highlights the importance of promoting active and healthy states in the population. As a mechanism to improve body composition, physical condition and perceived values of one's own physical condition and health status, the implementation of a strength training programme in the university community was proposed using a methodology based on Service-Learning. The participants were 12 students as coaches and 57 students from different university degrees as coachees (17 boys and 40 girls); the ages of the participants ranged from 18 to 33 years (M = 22.00; SD = 2.96). The variables of body composition, physical fitness, physical activity level and perception of fitness and health were assessed. Differences between pre- and post-intervention results were analysed using the Student's t-test and Wilcoxon test for ordinal self-perception variables. The results showed significant improvements in all the variables evaluated after the intervention. In conclusion, we would like to highlight the benefits of physical activity and the need to continue implementing action and intervention plans to encourage and promote its practice in all sectors of the population.

The use of phase angle in patients with digestive and liver diseases

Diseases of the liver and the digestive system can lead to malnutrition through an action of reduced food intake or nutrient use, inflammation and impaired metabolism, which result in substantial changes in body composition. Frequently, malnutrition manifests itself with weight loss and reduced muscle mass. However, weight loss and body mass index lack sensitivity to detect the loss of muscle mass and are not informative in distinguishing body water compartments and in characterizing their distribution. This issue is particularly relevant to these two disease models, which are frequently associated with fluid volume imbalances. Phase angle is a useful indicator for cell membrane integrity, water distribution between the intracellular and extracellular spaces and prediction of body cell mass as it is described by measured components of electrical impedance. Malnutrition, inflammation and oxidative stress impair electric tissue properties leading to lower values of PhA. In patients with inflammatory bowel and liver diseases, PhA was consistently found to be related to nutritional status and body composition, particularly the depletion of lean body mass and sarcopenia. It has been associated with prognosis, disease stage and severity and found to be helpful in monitoring fluid shifts and response to interventions.

Nascent to novel methods to evaluate malnutrition and frailty in the surgical patient

Preoperative nutrition status is an important determinant of surgical outcomes, yet malnutrition assessment is not integrated into all surgical pathways. Given its importance and the high prevalence of malnutrition in patients undergoing surgical procedures, preoperative nutrition screening, assessment, and intervention are needed to improve postoperative outcomes. This narrative review discusses novel methods to assess malnutrition and frailty in the surgical patient. The Global Leadership Initiative for Malnutrition (GLIM) criteria are increasingly used in surgical settings although further spread and implementation are strongly encouraged to help standardize the diagnosis of malnutrition. The use of body composition (ie, reduced muscle mass) as a phenotypic criterion in GLIM may lead to a greater number of patients identified as having malnutrition, which may otherwise be undetected if screened by other diagnostic tools. Skeletal muscle loss is a defining criterion of malnutrition and frailty. Novel direct and indirect approaches to assess muscle mass in clinical settings may facilitate the identification of patients with or at risk for malnutrition. Selected imaging techniques have the additional advantage of identifying myosteatosis (an independent predictor of morbidity and mortality for surgical patients). Feasible pathways for screening and assessing frailty exist and may determine the cost/benefit of surgery, long-term independence and productivity, and the value of undertaking targeted interventions. Finally, the evaluation of nutrition risk and status is essential to predict and mitigate surgical outcomes. Nascent to novel approaches are the future of objectively identifying patients at perioperative nutrition risk and guiding therapy toward optimal perioperative standards of care.

Good nutrition across the lifespan is foundational for healthy aging and sustainable development

Ensuring healthy lives and promoting wellbeing across the age spectrum are essential to sustainable development. Nutrition is at the heart of the World Health Organization (WHO) Sustainable Development Goals, particularly for Sustainable Development Goal 2/Subgoal 2, which is to End all forms of malnutrition by 2030. This subgoal addresses people of all ages, including targeted groups like young children and older adults. In recent decades, there have been marked advances in the tools and methods used to screen for risk of malnutrition and to conduct nutritional assessments. There have also been innovations in nutritional interventions and outcome measures related to malnutrition. What has been less common is research on how nutritional interventions can impact healthy aging. Our Perspective article thus takes a life-course approach to consider what is needed to address risk of malnutrition and why, and to examine how good nutrition across the lifespan can contribute to healthy aging. We discuss broad-ranging yet interdependent ways to improve nutritional status worldwide-development of nutritional programs and policies, incorporation of the best nutrition-care tools and methods into practice, provision of professional training for quality nutritional care, and monitoring health and economic benefits of such changes. Taken together, our Perspective aims to (i) identify current challenges to meeting these ideals of nutritional care, and to (ii) discover enabling strategies for the improvement of nutrition care across the lifespan. In harmony with the WHO goal of sustainable development, we underscore roles of nutrition to foster healthy human development and healthy aging worldwide.

Physical activity and body mass index were interactively related to health-related quality of life among older adults

PURPOSE

The purpose of this study was to examine how meeting physical activity (PA) guidelines (i.e., moderate-to-vigorous aerobic activity, muscle strengthening activity) and weight status were interactively related to health-related quality of life (HRQoL) among older adults.

METHODS

A cross-sectional analysis was conducted using data from 87,495 older adults aged 65+ years who participated in the U.S. 2019 Behavioral Risk Factor Surveillance System. PA, weight status, and HRQoL were assessed by validated questionnaires via phone interviews. Binomial logistic regression models were used to examine the interactive effects of meeting PA guidelines and weight status on the odds of having poor HRQoL after controlling for key confounders.

RESULTS

Compared to participants meeting both PA guidelines and with normal weight, both underweight and obese older adults had significantly higher odds of having poor general health (OR= 1.55-6.16) regardless of meeting PA guideline status, and those meeting muscle strengthening activities only or meeting neither PA guideline reported higher odds of poor physical health (OR= 1.83-6.22) regardless of weight status. Similarly, those meeting neither PA guideline had significantly higher odds of having poor mental health (OR= 1.69-2.78) regardless of weight status, and those meeting muscle strengthening activities only or meeting neither PA guideline reported higher odds of having frequent activity limitation days (OR= 2.18-7.05).

CONCLUSIONS

The positive associations between moderate-to-vigorous aerobic PA and HRQoL indicate the need to promote aerobic PA in older adults. Both sex and weight status should be considered when designing PA interventions to improve HRQoL among older adults.

Role of the Gut Microbiome in Skeletal Muscle Physiology and Pathophysiology

PURPOSE OF REVIEW

This review aims to summarize the recent findings about the contribution of the gut microbiome to muscle pathophysiology and discuss molecular pathways that may be involved in such process. Related findings in the context of cancer cachexia are outlined.

RECENT FINDINGS

Many bacterial metabolites have been reported to exert a beneficial or detrimental impact on muscle physiology. Most of the evidence concentrates on short-chain fatty acids (SCFAs), with an emerging role for bile acids, bacterial amino acid metabolites (bAAms), and bacterial polyphenol metabolites. Other molecular players worth considering include cytokines, hormones, lipopolysaccharides, and quorum sensing molecules. The current literature clearly establishes the ability for the gut microbiome to modulate muscle function and mass. The understanding of the mechanisms underlying this gut-muscle axis may lead to the delivery of novel therapeutic tools to tackle muscle wasting in cancer cachexia, chronic kidney disease, liver fibrosis, and age-related sarcopenia.

Efficacy of resistive exercise on skeletal muscle-related outcomes in cancer survivors: a systematic review protocol

BACKGROUND

Symptom burden and adverse treatment effects can negatively impact physical function, health-related outcomes, and quality of life in cancer survivors. Resistive exercise that improves skeletal muscle function can ameliorate these complications, but the central role of the skeletal muscle in mediating improvements in patient-related outcomes has not been explored. This protocol describes the rationale and methods for a systematic review that aims to determine the effects of resistive exercise on the skeletal muscle hypertrophy, muscle performance, and muscle-related biomarkers in cancer survivors.

METHODS

A systematic review will be conducted on peer-reviewed randomized controlled trials (RCTs) that employ resistive exercise interventions for cancer survivors. The following electronic databases will be searched: AMED, CENTRAL, CINAHL, CIRRIE, EMBASE, MEDLINE, PEDro, REHABDATA, Scopus, and SPORTDiscus. Studies will be considered for inclusion if they present quantitative data in adult cancer survivors on skeletal muscle characteristics (e.g., muscle mass), muscle performance (e.g., strength), or skeletal muscle-related biomarkers (e.g., myocellular satellite cells). Secondary outcomes will be physical function (e.g., stair climb) and patient-reported outcomes (e.g., fatigue). Data will be reported through a narrative that describes study design, participants, interventions, and outcome characteristics.

DISCUSSION

This systematic review will help clarify the influence of resistive exercise on factors relating to the skeletal muscle in adult cancer survivors. Findings may provide insight into optimal exercise selection for evidence-based practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: #277791 [under review].

Increased chest CT derived bone and muscle measures capture markers of improved morbidity and mortality in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a disease of accelerated aging and is associated with comorbid conditions including osteoporosis and sarcopenia. These extrapulmonary conditions are highly prevalent yet frequently underdiagnosed and overlooked by pulmonologists in COPD treatment and management. There is evidence supporting a role for bone-muscle crosstalk which may compound osteoporosis and sarcopenia risk in COPD. Chest CT is commonly utilized in COPD management, and we evaluated its utility to identify low bone mineral density (BMD) and reduced pectoralis muscle area (PMA) as surrogates for osteoporosis and sarcopenia. We then tested whether BMD and PMA were associated with morbidity and mortality in COPD.

METHODS

BMD and PMA were analyzed from chest CT scans of 8468 COPDGene participants with COPD and controls (smoking and non-smoking). Multivariable regression models tested the relationship of BMD and PMA with measures of function (6-min walk distance (6MWD), handgrip strength) and disease severity (percent emphysema and lung function). Multivariable Cox proportional hazards models were used to evaluate the relationship between sex-specific quartiles of BMD and/or PMA derived from non-smoking controls with all-cause mortality.

RESULTS

COPD subjects had significantly lower BMD and PMA compared with controls. Higher BMD and PMA were associated with increased physical function and less disease severity. Participants with the highest BMD and PMA quartiles had a significantly reduced mortality risk (36% and 46%) compared to the lowest quartiles.

CONCLUSIONS

These findings highlight the potential for CT-derived BMD and PMA to characterize osteoporosis and sarcopenia using equipment available in the pulmonary setting.

AGA-PancreasFest Joint Symposium on Exocrine Pancreatic Insufficiency

Exocrine pancreatic insufficiency (EPI) is a clinically defined syndrome based on the physician's assessment of a patient's maldigestion. However, current clinical definitions are inadequate in determining (1) the threshold of reduced pancreatic digestive enzyme secretion that determines "pancreatic insufficiency" in an individual patient; (2) the role of pancreatic function tests; (3) effects of differing metabolic needs, nutrition intake, and intestinal function/adaptation (4) when pancreatic enzyme replacement therapy is needed; and (5) how to monitor and titrate multiple therapies. Experts and key opinion leaders were invited to PancreasFest 2021 to discuss and help clarify mechanistic issues critical to defining EPI and to address misconceptions and barriers limiting advancements in patient care. Clinically EPI is defined as inadequate delivery of pancreatic digestive enzymes to meals to meet nutritional needs and is reversed with appropriate treatment. A new mechanistic definition of EPI was proposed that includes the disorders essence and character: (1) EPI is a disorder caused by failure of the pancreas to deliver a minimum/threshold level of specific pancreatic digestive enzymes to the intestine in concert with ingested nutrients, followed by enzymatic digestion of a series of individual snacks and meals over time to meet nutritional and metabolic needs, given (a) the specific macronutritional and micronutritional needs; (b) nutrient intake; (c) exocrine pancreatic function; and (d) intestinal anatomy, function, diseases, and adaptative capacity. (2) EPI is characterized by variable deficiencies in micronutrients and macronutrients, especially essential fats and fat-soluble vitamins, by gastrointestinal symptoms of nutrient maldigestion and by improvement or correction of nutritional state with lifestyle changes, disease treatment, optimized diet, dietary supplements, and/or administration of adequate pancreatic enzyme replacement therapy. EPI is complex and individualized and multidisciplinary approaches are needed to optimize therapy. Better pancreas function tests and biomarkers are needed to diagnose EPI and guide treatment.