Muscle Mass Loss in the Older Critically Ill Population: Potential Therapeutic Strategies

Simultaneous detection of myostatin-targeting monoclonal antibodies in dried blood spots and plasma using liquid chromatography-tandem mass spectrometry with field asymmetric ion mobility spectrometry

Transforming growth factor-β superfamily members, such as myostatin, growth/differentiation factor 11, and activin A, negatively regulate skeletal muscle mass. Inhibitors targeting these cytokines or activin receptor type IIB have the potential to treat muscular diseases and enhance physical performance. However, because of their effects on muscle mass and potential misuse, they are strictly prohibited in sports. Given the high potential for misuse as a doping agent in sports, effective analytical methods for these prohibited antibodies targeting these specific cytokines or their receptor are critically needed. In this study, we aimed to develop and validate a multitarget method to detect the prohibited transforming growth factor-β superfamily-targeting monoclonal antibodies, such as landogrozumab, domagrozumab, and the activin receptor type IIB-targeting antibody, bimagrumab, in human plasma and dried blood spot (DBS) samples using liquid chromatography-tandem mass spectrometry. Antibodies were purified from both the DBS and plasma samples using protein G magnetic beads and field-asymmetric ion mobility spectrometry (FAIMS) to minimize interference, followed by liquid chromatography-tandem mass spectrometry analysis. The validation process included tests for specificity, selectivity, linearity, limit of detection (LOD), limit of identification, precision, recovery, carryover effect, and matrix effect. The LODs for the target antibodies were identical in both DBS and plasma samples at 0.1 µg/mL for landogrozumab heavy and light chains, as well as 0.25 µg/mL for the domagrozumab light chain and 0.25 µg/mL for the bimagrumab heavy chain. However, the heavy chain of domagrozumab exhibited an LOD of 0.5 µg/mL in DBS and 1 µg/mL in plasma. The analytical method demonstrated strong linearity, with R² values greater than 0.99 for both plasma and DBS, and no carryover effect. Precision (CV%) was below 15 % at both middle (1 or 5 µg/mL; specific to the heavy chain of domagrozumab in plasma) and high (10 µg/mL) concentrations and was less than 20 % at the LOD. The selectivity and specificity indicated no interference in the analysis of target mAbs in different blood samples. Recovery was 31.6-49.8 % for DBS and 51.4-85.3 % for plasma, with no significant matrix effect. This study provides an effective method for doping analysis and novel protein detection.

Advances in nutritional metabolic therapy to impede the progression of critical illness

With the advancement of medical care and the continuous improvement of organ support technologies, some critically ill patients survive the acute phase of their illness but still experience persistent organ dysfunction, necessitating long-term reliance on intensive care and organ support, known as chronic critical illness. Chronic critical illness is characterized by prolonged hospital stays, high mortality rates, and significant resource consumption. Patients with chronic critical illness often suffer from malnutrition, compromised immune function, and poor baseline health, which, combined with factors like shock or trauma, can lead to intestinal mucosal damage. Therefore, effective nutritional intervention for patients with chronic critical illness remains a key research focus. Nutritional therapy has emerged as one of the essential components of the overall treatment strategy for chronic critical illness. This paper aims to provide a comprehensive review of the latest research progress in nutritional support therapy for patients with chronic critical illness.

Optimizing Recovery in Elderly Patients: Anabolic Benefits of Glucose Supplementation during the Rehydration Period

BACKGROUND

Since many acutely admitted older adults display signs of dehydration, treatment using balanced crystalloids is an important part of medical care. Additionally, many of these patients suffer from chronic malnutrition. We speculated that the early addition of glucose might ameliorate the hospital-related drop of caloric intake and modify their catabolic status.

METHODS

We included patients 78 years and older, admitted acutely for non-traumatic illnesses. The patients were randomized into either receiving balanced crystalloid (PlasmaLyte; group P) or balanced crystalloid enriched with 100 g of glucose per liter (group G). The information about fluid balance and levels of minerals were collected longitudinally.

RESULTS

In the G group, a significantly higher proportion of patients developed signs of refeeding syndrome, i.e., drops in phosphates, potassium and/or magnesium when compared to group P (83.3 vs. 16.7%, p < 0.01). The drop in phosphate levels was the most pronounced. The urinalysis showed no differences in the levels of these minerals in the urine, suggesting their uptake into the cells. There were no differences in the in-hospital mortality or in the 1-year mortality.

CONCLUSION

The short-term administration of balanced crystalloids with glucose induced an anabolic shift of electrolytes in acutely admitted older adults.

A Comparison of High and Usual Protein Dosing in Critically Ill Patients With Obesity: A Post Hoc Analysis of an International, Pragmatic, Single-Blinded, Randomized Clinical Trial

OBJECTIVES

Across guidelines, protein dosing for critically ill patients with obesity varies considerably. The objective of this analysis was to evaluate whether this population would benefit from higher doses of protein.

DESIGN

A post hoc subgroup analysis of the effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicenter, pragmatic, registry-based randomized trial.

SETTING

Eighty-five adult ICUs across 16 countries.

PATIENTS

Patients with obesity defined as a body mass index (BMI) greater than or equal to 30 kg/m 2 ( n = 425).

INTERVENTIONS

In the primary study, patients were randomized into a high-dose (≥ 2.2 g/kg/d) or usual-dose protein group (≤ 1.2 g/kg/d).

MEASUREMENTS AND MAIN RESULTS

Protein intake was monitored for up to 28 days, and outcomes (time to discharge alive [TTDA], 60-d mortality, days of mechanical ventilation [MV], hospital, and ICU length of stay [LOS]) were recorded until 60 days post-randomization. Of the 1301 patients in the primary study, 425 had a BMI greater than or equal to 30 kg/m 2 . After adjusting for sites and covariates, we observed a nonsignificant slower rate of TTDA with higher protein that ruled out a clinically important benefit (hazard ratio, 0.78; 95% CI, 0.58-1.05; p = 0.10). We found no evidence of difference in TTDA between protein groups when subgroups with different classes of obesity or patients with and without various nutritional and frailty risk variables were examined, even after the removal of patients with baseline acute kidney injury. Overall, 60-day mortality rates were 31.5% and 28.2% in the high protein and usual protein groups, respectively (risk difference, 3.3%; 95% CI, -5.4 to 12.1; p = 0.46). Duration of MV and LOS in hospital and ICU were not significantly different between groups.

CONCLUSIONS

In critically ill patients with obesity, higher protein doses did not improve clinical outcomes, including those with higher nutritional and frailty risk.

Understanding Post-Sepsis Syndrome: How Can Clinicians Help?

Sepsis is a global health challenge, with over 49 million cases annually. Recent medical advancements have increased in-hospital survival rates to approximately 80%, but the escalating incidence of sepsis, owing to an ageing population, rise in chronic diseases, and antibiotic resistance, have also increased the number of sepsis survivors. Subsequently, there is a growing prevalence of "post-sepsis syndrome" (PSS). This syndrome includes long-term physical, medical, cognitive, and psychological issues after recovering from sepsis. PSS puts survivors at risk for hospital readmission and is associated with a reduction in health- and life span, both at short and long term, after hospital discharge. Comprehensive understanding of PSS symptoms and causative factors is vital for developing optimal care for sepsis survivors, a task of prime importance for clinicians. This review aims to elucidate our current knowledge of PSS and its relevance in enhancing post-sepsis care provided by clinicians.

High prevalence of pre-existing sarcopenia in critically ill patients with hematologic malignancies admitted to the intensive care unit for sepsis or septic shock

BACKGROUND & AIMS

We aimed to evaluate body composition (BC) by computed tomography (CT) in hematologic malignancy (HM) patients admitted to the intensive care unit (ICU) for sepsis or septic shock.

METHODS

We retrospectively assessed BC and its impact on outcome of 186 patients at the 3rd lumbar (L3) and 12th thoracic vertebral levels (T12) using CT-scan performed before ICU admission.

RESULTS

The median patient age was 58.0 [47; 69] years. Patients displayed adverse clinical characteristics at admission with median [q1; q3] SAPS II and SOFA scores of 52 [40; 66] and 8 [5; 12], respectively. The mortality rate in the ICU was 45.7%. Overall survival rates at 1 month after admission in the pre-existing sarcopenic vs. non pre-existing sarcopenic patients were 47.9% (95% CI [37.6; 61.0]) and 55.0% (95% CI [41.6; 72.8]), p = 0.99), respectively, at the L3 level and 48.4% (95% CI [40.4; 58.0]) vs. 66.7% (95% CI [51.1; 87.0]), p = 0.062), respectively, at the T12 level.

CONCLUSIONS

Sarcopenia is assessable by CT scan at both the T12 and L3 levels and is highly prevalent in HM patients admitted to the ICU for severe infections. Sarcopenia may contribute to the high mortality rate in the ICU in this population.

Sarcopenia-a geriatric pandemic : A narrative review

With growing life expectancy, the prevalence of frailty and sarcopenia will continuously increase during the next decades. Geographical differences have been described, and depending on the population studied, sarcopenia is evident in 10% of community-dwelling people, increasing up to 40 to 50% among those living in nursing homes. Sarcopenia is a complex age-related process of multifactorial pathogenesis, influenced by lifestyle, nutrition, biological processes during aging, and also immunological and endocrine mechanisms. For diagnostic criteria, physical parameters (muscle mass measurement) and functional aspects (muscle strength, gait speed, physical performance) are required. In routine clinical care, screening patients using the SARC‑F questionnaire is recommended by recent guidelines of the European Workgroup for Sarcopenia.

Risk Factors of Decreased Abdominal Expiratory Muscle Thickness in Mechanically Ventilated Critically Ill Patients-The mNUTRIC Score is an Independent Predictor

Background

The expiratory abdominal skeletal muscles are an important component of the respiratory muscle pump, and their reduced thickness has been associated with difficult weaning. There is no objective score that may help clinicians to predict expiratory abdominal muscle thinning.

Patients and methods

This was a single-center retrospective study on 81 patients undergoing weaning from mechanical ventilation. The thickness of the four abdominal expiratory muscles-rectus abdominis (RA), internal oblique (IO), external oblique (EO), and transversus abdominis (TA) on the day of the first spontaneous breathing trial (SBT), was obtained. The various parameters of the patients with thinner RA, IO, EO, and TA below the determined thickness cut-off values, predicting difficult weaning was analyzed.

Results

Modified nutritional risk in critically ill (mNUTRIC) score was found to be an independent predictor of thinner IO muscle after logistic regression analysis [p = 0.001, adjusted OR 2.33, 95% CI (1.394-3.892)]. The mNUTRIC score was also an independent predictor of thinner EO (p = 0.014, adjusted OR 1.57) and RA muscle (p = 0.002, adjusted OR 1.69). The mNUTRIC cutoff score ≥4 predicted thinner IO (AUC 0.813, p < 0.001 sensitivity 71%, specificity 77%) and thinner EO (AUC 0.738, p < 0.001, 71% sensitivity, 67% specificity). The mNUTRIC score ≥3 predicted that at least one out of the four abdominal expiratory muscles will be thin (AUC 0.849, p < 0.001, 95% CI [0.763-0.935], sensitivity 87.5%, specificity 59%).

Conclusion

The mNUTRIC score is an independent predictor of thinner abdominal expiratory muscles in mechanically ventilated critically ill patients.

How to cite this article

Vishwas P, Amara V, Maddani SS, Chaudhuri S, Podder S. Risk Factors of Decreased Abdominal Expiratory Muscle Thickness in Mechanically Ventilated Critically Ill Patients-The mNUTRIC Score is an Independent Predictor. Indian J Crit Care Med 2023;27(1):8-15.

Safety and efficacy of electrical stimulation for lower-extremity muscle weakness in intensive care unit 2019 Novel Coronavirus patients: A phase I double-blinded randomized controlled trial

Background

Intensive care unit (ICU) prolonged immobilization may lead to lower-extremity muscle deconditioning among critically ill patients, particularly more accentuated in those with 2019 Novel Coronavirus (COVID-19) infection. Electrical stimulation (E-Stim) is known to improve musculoskeletal outcomes. This phase I double-blinded randomized controlled trial examined the safety and efficacy of lower-extremity E-Stim to prevent muscle deconditioning.

Methods

Critically ill COVID-19 patients admitted to the ICU were randomly assigned to control (CG) or intervention (IG) groups. Both groups received daily E-Stim (1 h) for up to 14 days on both gastrocnemius muscles (GNMs). The device was functional in the IG and non-functional in the CG. Primary outcomes included ankle strength (Ankle_s) measured by an ankle-dynamometer, and GNM endurance (GNM_e) in response to E-Stim assessed with surface electromyography (sEMG). Outcomes were measured at baseline, 3 and 9 days.

Results

Thirty-two (IG = 16, CG = 16) lower extremities in 16 patients were independently assessed. The mean time between ICU admission and E-Stim therapy delivery was 1.8 ± 1.9 days (p = 0.29). At 3 days, the IG showed an improvement compared to the CG with medium effect sizes for Ankle_s (p = 0.06, Cohen's d = 0.77) and GNM_e (p = 0.06, d = 0.69). At 9 days, the IG GNM_e was significantly higher than the CG (p = 0.04, d = 0.97) with a 6.3% improvement from baseline (p = 0.029). E-Stim did not alter vital signs (i.e., heart/respiratory rate, blood saturation of oxygen), showed no adverse events (i.e., pain, skin damage, discomfort), nor interfere with ICU standard of care procedures (i.e., mechanical ventilation, prone rotation).

Conclusion

This study supports the safety and efficacy of early E-Stim therapy to potentially prevent deterioration of lower-extremity muscle conditions in critically ill COVID-19 patients recently admitted to the ICU. If confirmed in a larger sample, E-Stim may be used as a practical adjunctive therapy.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [NCT04685213].

Musculoskeletal Ultrasound Shows Muscle Mass Changes during Post-Acute Care Hospitalization in Older Men: A Prospective Cohort Study

This study aimed to prospectively assess changes in muscle thickness (MT) and the cross-sectional area (CSA) of the rectus femoris (RF) muscle in a cohort of older adults, using musculoskeletal ultrasound at admission and at a 2-week follow-up during hospitalization in a post-acute care unit. Differences in frailty status and correlations of MT-RF and CSA-RF with current sarcopenia diagnostic criteria were also studied. Forty adults aged 79.5 (SD 9.5) years (57.5% women) participated, including 14 with frailty and 26 with pre-frailty. In the first week follow-up, men had a significant increase in MT (0.9 mm [95%CI 0.3 to 1.4], p = 0.003) and CSA (0.4 cm2 [95%CI 0.1 to 0.6], p = 0.007). During the second week, men continued to have a significant increase in MT (0.7 mm [95%CI 0.0 to 1.4], p = 0.036) and CSA (0.6 cm2 [95%CI 0.01 to 1.2], p = 0.048). Patients with frailty had lower values of MT-RF and CSA-RF at admission and during the hospitalization period. A moderate-to-good correlation of MT-RF and CSA with handgrip strength, fat-free mass and gait speed was observed. Musculoskeletal ultrasound was able to detect MT-RF and CSA-RF changes in older adults admitted to a post-acute care unit.

Neuromuscular electrical stimulation in the intensive care unit prevents muscle atrophy in critically ill older patients: A retrospective cohort study

Critically ill patients in the intensive care unit (ICU) develop muscle atrophy and decreased physical function. Though neuromuscular electrical stimulation (NMES) therapy has been shown to be effective in preventing this, but its effect on older patients is unknown. To examine the course of critically ill older patients treated with NMES in the ICU and to define the impact of its use. A retrospective cohort study was conducted using older ICU patients (≥65 years) categorized into a control group (n = 20) and an NMES group (n = 22). For subgroup analysis, each group was further classified into pre-old age (65-74 years) and old age (≥75 years). The control group showed significant decrease in muscle thickness during ICU and hospital stay. The NMES group showed lower reduction in muscle thickness and showed decrease in muscle echo intensity during hospital stay, compared to the control group. NMES inhibited decrease in muscle thickness in the pre-old age group versus the old age group. The decreasing effect of NMES on echo intensity during hospital stay manifested only in the pre-old age group. We did not find much difference in physical functioning between the NMES and control groups. Lower limb muscle atrophy reduces in critically ill older patients (≥65 years) with NMES and is pronounced in patients aged < 75 years. The impact of NMES on the physical functioning of older patients in ICU needs to be further investigated.

Disuse-induced skeletal muscle atrophy in disease and non-disease states in humans: mechanisms, prevention, and recovery strategies

Decreased skeletal muscle contractile activity (disuse) or unloading leads to muscle mass loss, also known as muscle atrophy. The balance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB) is the primary determinant of skeletal muscle mass. A reduced mechanical load on skeletal muscle is one of the main external factors leading to muscle atrophy. However, endocrine and inflammatory factors can act synergistically in catabolic states, amplifying the atrophy process and accelerating its progression. Additionally, older individuals display aging-induced anabolic resistance, which can predispose this population to more pronounced effects when exposed to periods of reduced physical activity or mechanical unloading. Different cellular mechanisms contribute to the regulation of muscle protein balance during skeletal muscle atrophy. This review summarizes the effects of muscle disuse on muscle protein balance and the molecular mechanisms involved in muscle atrophy in the absence or presence of disease. Finally, a discussion of the current literature describing efficient strategies to prevent or improve the recovery from muscle atrophy is also presented.

β-Hydroxy-β-methylbutyrate (HMB) supplementation and functional outcomes in multi-trauma patients: a study protocol for a pilot randomised clinical trial (BOOST trial)

Background

There are no therapies proven to diminish the muscle wasting that occurs in patients after major trauma who are admitted to the intensive care unit (ICU). β-Hydroxy-β-methylbutyrate (HMB) is a nutrition intervention that may attenuate muscle loss and, thereby, improve recovery. The primary aim of this study is to determine the feasibility of a blinded randomised clinical trial of HMB supplementation to patients after major trauma who are admitted to the ICU. Secondary aims are to establish estimates for the impact of HMB when compared to placebo on muscle mass and nutrition-related patient outcomes.

Methods

This prospective, single-centre, blinded, randomised, placebo-controlled, parallel-group, feasibility trial with allocation concealment will recruit 50 participants over 18 months. After informed consent, participants will be randomised [1:1] to receive either the intervention (three grams of HMB dissolved in either 150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed) or placebo (150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed). The intervention will be commenced in ICU, continued after ICU discharge and ceased at hospital discharge or day 28 post randomisation, whichever occurs first. The primary outcome is the feasibility of administering the intervention. Secondary outcomes include change in muscle thickness using ultrasound and other nutritional and patient-centred outcomes.

Discussion

This study aims to determine the feasibility of administering HMB to critically ill multi-trauma patients throughout ICU admission until hospital discharge. Results will inform design of a larger randomised clinical trial.

Trial registration

The protocol is registered with Australian New Zealand Clinical Trials Registry (ANZCTR) ANZCTR: 12620001305910. UTN: U1111-1259-5534.

Preoperative Muscle Strength Is a Predictor of Outcomes After Esophagectomy

BACKGROUND

Sarcopenia, loss of muscle mass and strength, has been associated with more frequent complications after esophagectomy. This study compared hand-grip strength, muscle mass, and intramuscular adipose tissue as predictors of postoperative outcomes and mortality after esophagectomy.

METHODS

Minimally invasive esophagectomy was performed on 175 patients with esophageal cancer. Skeletal muscle index and skeletal muscle density were derived from preoperative CTs. Hand-grip strength was measured using dynamometer. Univariate and multivariable analyses were performed.

RESULTS

Preoperative hand-grip strength was normal in 91 (52%), intermediate in 43 (25%), and weak in 41 (23%) patients. Hand-grip strength was significantly correlated with both skeletal muscle index and skeletal muscle density. Postoperative pneumonia occurred in 8/41 (20%) patients with weak strength compared to 4/91 (4%) with normal strength (p = 0.006; Cochran-Armitage Test). Prolonged postoperative ventilation occurred in 11/41 (27%) patients with weak strength compared to 11/91 (12%) with normal strength (p = 0.036). Median length of stay was 9 days in patients with weak strength compared to 7 days for those with normal strength (p = 0.005; Kruskal-Wallis Test). Discharge to non-home location occurred in 15/41 (37%) with weak strength compared to 8/91 (9%) with normal strength (p < 0.001). Postoperative mortality at 90 days was 4/41 (10%) with weak strength compared with no mortalities (0/91) in the normal strength group (p = 0.004). Mortality at 1 year was 18/39 (46%) in patients with weak strength compared to 6/81 (7%) with normal strength, among 158 patients with 1-year follow-up (p < 0.001).

CONCLUSIONS

Preoperative hand-grip strength was found to be a powerful predictor of postoperative pneumonia, length of stay, discharge to non-home location, and mortality after esophagectomy.

Prevalence and Associated Factors of Coexistence of Malnutrition and Sarcopenia in Geriatric Rehabilitation

Malnutrition and sarcopenia often coexist in rehabilitation patients, although they are often overlooked and undertreated in clinical practice. This cross-sectional study aimed to clarify the prevalence of the coexistence of malnutrition and sarcopenia (Co-MS) and its associated factors in convalescent rehabilitation wards in Japan. Consecutive patients aged ≥ 65 years in convalescent rehabilitation wards between November 2018 and October 2020 were included. Malnutrition and sarcopenia were determined by the Global Leadership Initiative on Malnutrition (GLIM) criteria and the Asian Working Group for Sarcopenia (AWGS 2019) criteria, respectively. Patients who presented both with malnutrition and sarcopenia were classified as Co-MS. Potentially associated factors included age, sex, days from onset to admission of rehabilitation wards, reason for admission, pre-morbid functional dependency, comorbidity, activities of daily living, swallowing ability, and oral function and hygiene. The prevalence of malnutrition, sarcopenia, and Co-MS was calculated. Binary logistic regression analyses were performed to compute odds ratios (ORs) and the 95% confidence interval (CI) of possible associated factors for each condition. Overall, 601 patients were eligible for the analysis (median 80 years old, 355 female patients, 70% cerebrovascular disease). Co-MS, malnutrition, and sarcopenia were found in 23.5%, 29.0%, and 62.4% of the enrolled patients, respectively. After adjustment, onset–admission interval (OR = 1.04; 95% CI = 1.02 to 1.06), hospital-associated deconditioning (OR = 4.62; 95% CI = 1.13 to 18.8), and swallowing ability (Food Intake LEVEL Scale) (OR = 0.83; 95% CI = 0.73 to 0.93) were identified as independent explanatory factors of Co-MS. In conclusion, Co-MS was prevalent in geriatric rehabilitation patients; thus, healthcare professionals should be aware of the associated factors to detect the geriatric rehabilitation patients who are at risk of both malnutrition and sarcopenia, and to provide appropriate treatments.

Targeting cancer via ribosome biogenesis: the cachexia perspective

Cancer cachexia afflicts many advanced cancer patients with many progressing to death. While there have been many advancements in understanding the molecular mechanisms that contribute to the development of cancer cachexia, substantial gaps still exist. Chemotherapy drugs often target ribosome biogenesis to slow or blunt tumor cell growth and proliferation. Some of the most frequent side-effects of chemotherapy are loss of skeletal muscle mass, muscular strength and an increase in fatigue. Given that ribosome biogenesis has emerged as a main mechanism regulating muscle hypertrophy, and more recently, also implicated in muscle atrophy, we propose that some chemotherapy drugs can cause further muscle wasting via its effect on skeletal muscle cells. Many chemotherapy drugs, including the most prescribed drugs such as doxorubicin and cisplatin, affect ribosomal DNA transcription, or other pathways related to ribosome biogenesis. Furthermore, middle-aged and older individuals are the most affected population with cancer, and advanced cancer patients often show reduced levels of physical inactivity. Thus, aging and inactivity can themselves affect muscle ribosome biogenesis, which can further worsen the effect of chemotherapy on skeletal muscle ribosome biogenesis and, ultimately, muscle mass and function. We propose that chemotherapy can accelerate the onset or worsen cancer cachexia via its inhibitory effects on skeletal muscle ribosome biogenesis. We end our review by providing recommendations that could be used to ameliorate the negative effects of chemotherapy on skeletal muscle ribosome biogenesis.

Resistance Exercise, Aging, Disuse, and Muscle Protein Metabolism

Skeletal muscle is the organ of locomotion, its optimal function is critical for athletic performance, and is also important for health due to its contribution to resting metabolic rate and as a site for glucose uptake and storage. Numerous endogenous and exogenous factors influence muscle mass. Much of what is currently known regarding muscle protein turnover is owed to the development and use of stable isotope tracers. Skeletal muscle mass is determined by the meal- and contraction-induced alterations of muscle protein synthesis and muscle protein breakdown. Increased loading as resistance training is the most potent nonpharmacological strategy by which skeletal muscle mass can be increased. Conversely, aging (sarcopenia) and muscle disuse lead to the development of anabolic resistance and contribute to the loss of skeletal muscle mass. Nascent omics-based technologies have significantly improved our understanding surrounding the regulation of skeletal muscle mass at the gene, transcript, and protein levels. Despite significant advances surrounding the mechanistic intricacies that underpin changes in skeletal muscle mass, these processes are complex, and more work is certainly needed. In this article, we provide an overview of the importance of skeletal muscle, describe the influence that resistance training, aging, and disuse exert on muscle protein turnover and the molecular regulatory processes that contribute to changes in muscle protein abundance. © 2021 American Physiological Society. Compr Physiol 11:2249-2278, 2021.

Impact of Tailored Multicomponent Exercise for Prevent Weakness and Falls on Nursing Home Residents' Functional Capacity

OBJECTIVES

We aimed to determine whether the benefits of long (24 weeks) and short (4 weeks) training programs persisted after short (6 weeks) and long (14 weeks) periods of inactivity in older adult nursing home residents with sarcopenia.

DESIGN

Multicenter randomized trial.

INTERVENTION

The Vivifrail tailored, multicomponent exercise program (http://vivifrail.com) was conducted to individually prescribe exercise for frail older adults, depending on their functional capacity. The training included 4 levels combining strength and power, balance, flexibility, and cardiovascular endurance exercises.

SETTING AND PARTICIPANTS

Twenty-four institutionalized older adults (87.1 ± 7.1 years, 58.3% women) diagnosed with sarcopenia were allocated into 2 groups: the Long Training-Short Detraining (LT-SD) group completed 24 weeks of supervised Vivifrail training followed by 6 weeks of detraining; the Short Training-Long Detraining (ST-LD) group completed 4 weeks of training and 14 weeks of detraining.

MEASURES

Changes in functional capacity and strength were evaluated at baseline, and after short and long training and detraining periods.

RESULTS

Benefits after short and long exercise interventions persisted when compared with baseline. Vivifrail training was highly effective in the short term (4 weeks) in increasing functional and strength performance (effect size = 0.32-1.44, P < .044) with the exception of handgrip strength. Continued training during 24 weeks produced 10% to 20% additional improvements (P < .036). Frailty status was reversed in 36% of participants, with 59% achieving high self-autonomy. Detraining resulted in a 10% to 25% loss of strength and functional capacity even after 24 weeks of training (effects size = 0.24-0.92, P < .039).

CONCLUSIONS AND IMPLICATIONS

Intermittent strategies such as 4 weeks of supervised exercise 3 times yearly with no more than 14 weeks of inactivity between exercise periods appears as an efficient solution to the global challenge of maintaining functional capacity and can even reverse frailty in vulnerable institutionalized older adults.

Optimal Nutritional Factors Influencing the Duration of Mechanical Ventilation Among Adult Patients with Critical Illnesses in an Intensive Care Unit

Objective

This study aims to identify the impact of nutritional factors on mechanical ventilation duration for critical patients.

Patients and Methods

The current study was a single-center, prospective observational design which enrolled one-hundred critically ill patients who were admitted to an intensive care unit (ICU). It demonstrates purposive sampling and also performs the descriptive nutritional factors influencing the mechanical ventilation duration. Daily calories target requirement scale (DCRS), subjective global assessment form (SGA), dyspnea assessment form, and APACHE II have been used as methods in the study along with time to initial enteral nutrition (EN) after 24-hour admission and daily calories target requirement over 7 days to assess patients. Data is analyzed using the multiple regressions.

Results

As a result, nutritional status monitoring, time to initial EN, calories and target requirements are statistically positive significance associated with the mechanical ventilation duration respectively (R = 0.54, R = 0.30, R= 0.40, p < 0.05). However, age, illness severity, and dyspnea scales are not associated with the mechanical ventilation duration (p> 0.05). Therefore, the nutritional status, malnutrition scores and calorie target requirements can be used to significantly predict the mechanical ventilation duration. The predictive power is 58 and 28.0% of variance. The most proper influencer to predict the mechanical ventilation duration is nutritional status or malnutrition scores.

Conclusion

The research findings show that the nutritional status, time to initial EN, and calorie target requirement within 7 days of admission are associated with the mechanical ventilation duration in the critical patients. Therefore, it can be used to develop guidelines reducing the mechanical ventilation duration and to promote the ventilator halting for critical patients.

Nutritional Concerns for Cancer, Cachexia, Frailty, and Sarcopenia in Canine and Feline Pets

Cachexia and frailty can be described as independent entities yet are interrelated as constituents of malnutrition and the aging process. The unifying aspect is lean muscle loss, ultimately driven by inflammation and the adverse ramifications to pets with chronic, debilitating, or terminal disease states, including cancer. Modification to intake of dietary protein, fat, omega-3 fatty acids, and selected vitamins has shown benefit in management protocols as preventative and palliative care, but further investigation is imperative.