Of Greek heroes, wiggling worms, mighty mice, and old body builders

Prognostic value of initial and longitudinal changes in body composition in metastatic pancreatic cancer

BACKGROUND

Sarcopenia or visceral adipose tissue has been reported to be related to pancreatic cancer prognosis. However, clinical relevance of the comprehensive analysis of body compositions and their longitudinal changes is lacking. This study analysed the association between body composition changes after chemotherapy and survival in patients with metastatic pancreatic cancer.

METHODS

We retrospectively included 456 patients (mean age ± standard deviation, 61.2 ± 10.0 years; 272 males and 184 females) with metastatic pancreatic cancer who received palliative chemotherapy from May 2011 to December 2019. Using deep learning-based, fully automated segmentation of contrast-enhanced computed tomography (CT) at the time of diagnosis, cross-sectional areas of muscle, subcutaneous adipose tissue and visceral adipose tissue were extracted from a single axial image of the portal venous phase at L3 level. Skeletal muscle index (SMI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI) and mean skeletal muscle attenuation (MA) were calculated, and their effect on overall survival (OS) was analysed. Longitudinal changes in body composition and prognostic values were also analysed in a subgroup of patients with 2- and 6-month follow-up CT (n = 349).

RESULTS

A total of 452 deaths occurred during follow-up in the entire cohort. The survival rate was 49.3% (95% confidence interval [CI], 44.9-54.2) at 1 year and 3.7% (95% CI, 2.0-6.8) at 5 years. In multivariable analysis, higher MA (≥44.4 HU in males and ≥34.8 HU in females) at initial CT was significantly associated with better OS in both males and females (adjusted hazard ratio [HR], 0.706; 95% CI, 0.538-0.925; P = 0.012 for males, and HR, 0.656; 95% CI, 0.475-0.906; P = 0.010 for females), whereas higher SATI (≥42.8 cm2/m2 in males and ≥65.8 cm2/m2 in females) was significantly associated with better OS in female patients only (adjusted HR, 0.568; 95% CI, 0.388-0.830; P = 0.003). In longitudinal analysis, SMI, VATI and SATI significantly decreased between initial and 2-month follow-up CT, whereas mean MA significantly decreased between 2- and 6-month follow-up CT. In multivariable Cox regression analysis of longitudinal changes, which was stratified by disease control state, SATI change was significantly associated with OS in male patients (adjusted HR, 0.513; 95% CI, 0.354-0.745; P < 0.001), while other body composition parameters were not.

CONCLUSIONS

In patients with metastatic pancreatic cancer, body composition mostly changed during the first 2 months after starting chemotherapy, and the prognostic factors associated with OS differed between males and females. Initial and longitudinal changes of body composition are associated with OS of metastatic pancreatic cancer.

From Chronodisruption to Sarcopenia: The Therapeutic Potential of Melatonin

Sarcopenia is an age-related condition that involves a progressive decline in muscle mass and function, leading to increased risk of falls, frailty, and mortality. Although the exact mechanisms are not fully understood, aging-related processes like inflammation, oxidative stress, reduced mitochondrial capacity, and cell apoptosis contribute to this decline. Disruption of the circadian system with age may initiate these pathways in skeletal muscle, preceding the onset of sarcopenia. At present, there is no pharmacological treatment for sarcopenia, only resistance exercise and proper nutrition may delay its onset. Melatonin, derived from tryptophan, emerges as an exceptional candidate for treating sarcopenia due to its chronobiotic, antioxidant, and anti-inflammatory properties. Its impact on mitochondria and organelle, where it is synthesized and crucial in aging skeletal muscle, further highlights its potential. In this review, we discuss the influence of clock genes in muscular aging, with special reference to peripheral clock genes in the skeletal muscle, as well as their relationship with melatonin, which is proposed as a potential therapy against sarcopenia.

Age Is Just a Number: Progress and Obstacles in the Discovery of New Candidate Drugs for Sarcopenia

Sarcopenia is a disease characterized by the progressive loss of skeletal muscle mass and function that occurs with aging. The progression of sarcopenia is correlated with the onset of physical disability, the inability to live independently, and increased mortality. Due to global increases in lifespan and demographic aging in developed countries, sarcopenia has become a major socioeconomic burden. Clinical therapies for sarcopenia are based on physical therapy and nutritional support, although these may suffer from low adherence and variable outcomes. There are currently no clinically approved drugs for sarcopenia. Consequently, there is a large amount of pre-clinical research focusing on discovering new candidate drugs and novel targets. In this review, recent progress in this research will be discussed, along with the challenges that may preclude successful translational research in the clinic. The types of drugs examined include mitochondria-targeting compounds, anti-diabetes agents, small molecules that target non-coding RNAs, protein therapeutics, natural products, and repositioning candidates. In light of the large number of drugs and targets being reported, it can be envisioned that clinically approved pharmaceuticals to prevent the progression or even mitigate sarcopenia may be within reach.

[Frequency and severity of sarcopenia in patients with inflammatory and noninflammatory musculoskeletal diseases : Results of a monocentric study in a tertiary care center]

INTRODUCTION

Sarcopenia (SP) is defined as the pathological loss of muscle mass and function. This is a clinically relevant problem, especially in geriatric patients, because SP is associated with falls, frailty, loss of function, and increased mortality. People with inflammatory and degenerative rheumatic musculoskeletal disorders (RMD) are also at risk for developing SP; however, there is little research on the prevalence of this health disorder in this patient group using currently available SP criteria.

OBJECTIVE

To investigate the prevalence and severity of SP in patients with RMD.

METHODS

A total of 141 consecutive patients over 65 years of age with rheumatoid arthritis (RA), spondylarthritis (SpA), vasculitis, and noninflammatory musculoskeletal diseases were recruited in a cross-sectional study at a tertiary care center. The European Working Group on Sarcopenia in Older People (EWGSOP 1 and 2) definitions of presarcopenia, SP, and severe SP were used to determine the prevalence. Lean mass as a parameter of muscle mass and bone density were measured by dual X‑ray absorptiometry (DXA). Handgrip strength and the short physical performance battery (SPPB) were performed in a standardized manner. Furthermore, the frequency of falls and the presence of frailty were determined. Student's T-test and the χ2-test were used for statistics.

RESULTS

Of the patients included 73% were female, the mean age was 73 years and 80% had an inflammatory RMD. According to EWGSOP 2, 58.9% of participants probable had SP due to low muscle function. When muscle mass was added for confirmation, the prevalence of SP was 10.6%, 5.6% of whom had severe SP. The prevalence was numerically but not statistically different between inflammatory (11.5%) and noninflammatory RMD (7.1%). The prevalence of SP was highest in patients with RA (9.5%) and vasculitis (24%), and lowest in SpA (4%). Both osteoporosis (40% vs. 18.5%) and falls (15% vs. 8.6%) occurred more frequently in patients with SP than those without SP.

DISCUSSION

This study showed a relatively high prevalence of SP, especially in patients with RA and vasculitis. In patients at risk, measures to detect SP should routinely be performed in a standardized manner in the clinical practice. The high frequency of muscle function deficits in this study population supports the importance of measuring muscle mass in addition to bone density with DXA to confirm SP.

Deletion of quinolinate phosphoribosyltransferase gene accelerates frailty phenotypes and neuromuscular decline with aging in a sex-specific pattern

Decline in neuromuscular function with aging is known to be a major determinant of disability and all-cause mortality in late life. Despite the importance of the problem, the neurobiology of age-associated muscle weakness is poorly understood. In a previous report, we performed untargeted metabolomics on frail older adults and discovered prominent alteration in the kynurenine pathway, the major route of dietary tryptophan degradation that produces neurotoxic intermediate metabolites. We also showed that neurotoxic kynurenine pathway metabolites are correlated with increased frailty score. For the present study, we sought to further examine the neurobiology of these neurotoxic intermediates by utilizing a mouse model that has a deletion of the quinolinate phosphoribosyltransferase (QPRT) gene, a rate-limiting step of the kynurenine pathway. QPRT-/- mice have elevated neurotoxic quinolinic acid level in the nervous system throughout their lifespan. We found that QPRT-/- mice have accelerated declines in neuromuscular function in an age- and sex-specific manner compared to control strains. In addition, the QPRT-/- mice show premature signs of frailty and body composition changes that are typical for metabolic syndrome. Our findings suggest that the kynurenine pathway may play an important role in frailty and age-associated muscle weakness.

Effects of Exercise Training on Muscle Quality in Older Individuals: A Systematic Scoping Review with Meta-Analyses

BACKGROUND

The quantity and quality of skeletal muscle are important determinants of daily function and metabolic health. Various forms of physical exercise can improve muscle function, but this effect can be inconsistent and has not been systematically examined across the health-neurological disease continuum. The purpose of this systematic scoping review with meta-analyses was to determine the effects and potential moderators of exercise training on morphological and neuromuscular muscle quality (MMQ, NMQ) in healthy older individuals. In addition and in the form of a scoping review, we examined the effects of exercise training on NMQ and MMQ in individuals with neurological conditions.

METHODS

A systematic literature search was performed in the electronic databases Medline, Embase, and Web of Science. Randomized controlled trials were included that examined the effects of exercise training on muscle quality (MQ) in older individuals with and without neurological conditions. Risk of bias and study quality were assessed (Cochrane Risk of Bias Tool 2.0). We performed random-effects models using robust variance estimation and tested moderators using the approximate Hotelling-Zhang test.

RESULTS

Thirty studies (n = 1494, 34% females) in healthy older individuals and no studies in individuals with neurological conditions were eligible for inclusion. Exercise training had small effects on MMQ (g = 0.21, 95% confidence interval [CI]: 0.03-0.40, p = 0.029). Heterogeneity was low (median I² = 16%). Training and demographic variables did not moderate the effects of exercise on MMQ. There was no association between changes in MMQ and changes in functional outcomes. Exercise training improved NMQ (g = 0.68, 95% CI 0.35-1.01, p < 0.000) across all studies, in particular in higher-functioning older individuals (g = 0.72, 95% CI 0.38-1.06, p < 0.001), in lower extremity muscles (g = 0.74, 95% CI 0.35-1.13, p = 0.001), and after resistance training (g = 0.91; 95% CI 0.42-1.41, p = 0.001). Heterogeneity was very high (median I² = 79%). Of the training and demographic variables, only resistance training moderated the exercise-effects on NMQ. High- versus low-intensity exercise moderated the exercise-effects on NMQ, but these effects were considered unreliable due to a low number of studies at high intensity. There was no association between changes in NMQ and changes in functional outcomes.

CONCLUSION

Exercise training has small effects on MMQ and medium-large effects on NMQ in healthy older individuals. There was no association between improvements in MQ and increases in muscle strength, mobility, and balance. Information on dose-response relations following training is currently lacking. There is a critical gap in muscle quality data for older individuals with lower function and neurological conditions after exercise training. Health practitioners should use resistance training to improve muscle function in older individuals. Well-designed studies are needed to examine the relevance of exercise training-induced changes in MQ in daily function in older individuals, especially to those with lower function and neurological conditions.

Sarcopenia as a potential risk factor for senile blepharoptosis: Nationwide Surveys (KNHANES 2008–2011)

As the world’s population is aging, sarcopenia is recognized as essential to assess people’s lifelong condition and do appropriate early intervention. Senile blepharoptosis is also a problem in old age deteriorating visual function and causing a cosmetic decline. We investigated the association between sarcopenia and the prevalence of senile blepharoptosis, using a nationwide representative survey in Korea. A total of 11,533 participants were recruited. We used the body mass index (BMI)- adjusted appendicular skeletal muscle (ASM) definition as the muscle mass index (MMI, ASM [kg] divided by BMI [kg/m2]). The association between blepharoptosis prevalence and MMI was analyzed using multivariate logistic regression. Sarcopenia, defined as the lowest MMI quintile group in both men and women, was also associated with the prevalence of blepharoptosis (ORs 1.92, 95% CI 1.17–2.16; p < 0.001). These associations remained statistically significant after adjusting for various factors related to blepharoptosis using multivariate analysis (ORs 1.18, 95% CI 1.04–1.34; p = 0.012). Moreover, MMI was found to have a proportional relationship with eyelid lifting force (levator function), which is closely related to the occurrence and severity of ptosis. Sarcopenia is related to the prevalence of senile blepharoptosis, and patients with lower MMI were more likely to have blepharoptosis. These results suggest that sarcopenia can affect visual function and aesthetics.

Brachial-Ankle Pulse Wave Velocity Mediates the Association between Increased Age and Risk of Sarcopenia among Chinese Patients with Type 2 Diabetes Mellitus

BACKGROUND AND AIMS

Arterial stiffness and sarcopenia are commonly seen in patients with type 2 diabetes mellitus (T2DM), and both are age-related diseases. However, few studies have addressed the causal relationship between age, arterial stiffness, and sarcopenia, especially in patients with T2DM. This study is aimed at investigating the relationship among age, arterial stiffness, and sarcopenia in patients with T2DM.

METHODS AND RESULTS

This cross-sectional study enrolled 557 inpatients with diabetes at the First Affiliated Hospital of Wenzhou Medical University, China, between June 2020 and July 2021. Patients who were diagnosed with T2DM and underwent examination of dual-energy X-ray absorptiometry, handgrip strength, 6-meter walk speed, and brachial-ankle pulse wave velocity (baPWV, a recognized indicator of arterial stiffness) were enrolled. A total of 447 patients were included. A dose-dependent relationship was found between age and sarcopenia. We also found a dose-dependent relationship between age and baPWV. Similarly, significant dose-dependent relationships were found across baPWV tertiles with higher prevalence of sarcopenia. Then, a mediation analysis was performed to explore the mediation effect of arterial stiffness on age-associated sarcopenia. We found that the prevalence of sarcopenia increased by 0.0115 (95% CI, 0.0028-0.0239) per 1 year increase in age by the mediation effect of baPWV and that the direct effect of aging on sarcopenia was 0.0441 (95% CI, 0.0101-0.0909) per 1 year older. baPWV mediated 20.5% of the positive relationship between increased age and the prevalence of sarcopenia.

CONCLUSIONS

Elevated baPWV partially mediates the association of age and sarcopenia among patients with T2DM.

From mitochondria to sarcopenia: role of 17β-estradiol and testosterone

Sarcopenia, characterized by a loss of muscle mass and strength with aging, is prevalent in older adults. Although the exact mechanisms underlying sarcopenia are not fully understood, evidence suggests that the loss of mitochondrial integrity in skeletal myocytes has emerged as a pivotal contributor to the complex etiology of sarcopenia. Mitochondria are the primary source of ATP production and are also involved in generating reactive oxygen species (ROS), regulating ion signals, and initiating apoptosis signals in muscle cells. The accumulation of damaged mitochondria due to age-related impairments in any of the mitochondrial quality control (MQC) processes, such as proteostasis, biogenesis, dynamics, and mitophagy, can contribute to the decline in muscle mass and strength associated with aging. Interestingly, a decrease in sex hormones (e.g., 17β-estradiol and testosterone), which occurs with aging, has also been linked to sarcopenia. Indeed, 17β-estradiol and testosterone targeted mitochondria and exhibited activities in regulating mitochondrial functions. Here, we overview the current literature on the key mechanisms by which mitochondrial dysfunction contribute to the development and progression of sarcopenia and the potential modulatory effects of 17β-estradiol and testosterone on mitochondrial function in this context. The advance in its understanding will facilitate the development of potential therapeutic agents to mitigate and manage sarcopenia.

Exercise as an Aging Mimetic: A New Perspective on the Mechanisms Behind Exercise as Preventive Medicine Against Age-Related Chronic Disease

Age-related chronic diseases are among the most common causes of mortality and account for a majority of global disease burden. Preventative lifestyle behaviors, such as regular exercise, play a critical role in attenuating chronic disease burden. However, the exact mechanism behind exercise as a form of preventative medicine remains poorly defined. Interestingly, many of the physiological responses to exercise are comparable to aging. This paper explores an overarching hypothesis that exercise protects against aging/age-related chronic disease because the physiological stress of exercise mimics aging. Acute exercise transiently disrupts cardiovascular, musculoskeletal, and brain function and triggers a substantial inflammatory response in a manner that mimics aging/age-related chronic disease. Data indicate that select acute exercise responses may be similar in magnitude to changes seen with +10-50 years of aging. The initial insult of the age-mimicking effects of exercise induces beneficial adaptations that serve to attenuate disruption to successive "aging" stimuli (i.e., exercise). Ultimately, these exercise-induced adaptations reduce the subsequent physiological stress incurred from aging and protect against age-related chronic disease. To further examine this hypothesis, future work should more intricately describe the physiological signature of different types/intensities of acute exercise in order to better predict the subsequent adaptation and chronic disease prevention with exercise training in healthy and at-risk populations.

Prevalence, physical characteristics, and fall risk in older adults with and without possible sarcopenia

BACKGROUND

Recently, the Asian Working Group for Sarcopenia (AWGS) 2019 consensus redefined the sarcopenia including possible sarcopenia, sarcopenia and severe sarcopenia and grip strength cutoff value by sex.

AIMS

This study aimed to assess the prevalence, physical characteristics, physical fitness, and fall risk in older adults living in local communities, with possible sarcopenia using the diagnostic criteria suggested by the AWGS 2WG.

METHODS

A total of 431 participants (123 men and 308 women) aged 65-97 years were enrolled in this study. Based on the diagnostic criteria of possible sarcopenia suggested by AWGS 2, study participants were divided into normal and possible sarcopenia (grip strength: < 28 kg and < 18 kg for men and women, respectively) groups. Independent t-tests and logistic regression analyses were conducted to compare the differences between the two groups.

RESULTS

The possible prevalence of sarcopenia was 23.7%. Possible sarcopenia was present in older adults with lower weight, body mass index (BMI), skeletal muscle mass, and fat-free mass (P < 0.05) than those in the normal group. Older men with possible sarcopenia had poorer upper and lower body strength, aerobic endurance, lower body flexibility, agility and dynamic balance, and a higher fall risk than those in the normal group (P < 0.05). Older women with possible sarcopenia had a 2.5-fold and 3.3-fold higher fall risk than women in the normal group in both an unadjusted model (P = 0.001) and in a model adjusted for age and BMI (P < 0.001). However, there were no significant differences in fall risk among older men.

CONCLUSION

The diagnostic criteria suggested by AWGS 2 may be highly useful for screening for declining physical function.

Phase angle from bioelectrical impedance analysis is a useful indicator of muscle quality

BACKGROUND

Methods that facilitate muscle quality measurement may improve the diagnosis of sarcopenia. Current research has focused on the phase angle (PhA) obtained through bioelectrical impedance analysis (BIA) as an indicator of cellular health, particularly cell membrane integrity and cell function. The current study therefore aimed to evaluate the relationship between the PhA and muscle quality and muscle-related parameters and to determine factors associated with the PhA. Moreover, we attempted to determine the cut-off value of PhA for predicting sarcopenia.

METHODS

First-year university students (830 male students, 18.5 ± 0.6 years old; 422 female students, 18.3 ± 0.5 years old) and community-dwelling elderly individuals (70 male individuals, 74.4 ± 5.5 years old; 97 female individuals, 73.1 ± 6.4 years old) were included. PhA and other body composition data were measured using BIA, while muscle quality was calculated by dividing handgrip strength by upper limbs muscle mass. The relationship between PhA and the aforementioned parameters were then analysed, after which the cut-off value of PhA for predicting sarcopenia was examined.

RESULTS

Multiple linear regression analysis revealed that age, skeletal muscle mass index (SMI), and muscle quality were independently associated with PhA in both sexes [male (age: standardized regression coefficient (β) = -0.43, P < 0.001, SMI: β = 0.61, P < 0.001, muscle quality: β = 0.13, P < 0.001) and female (age: β = -0.56, P < 0.001, SMI: β = 0.52, P < 0.001, muscle quality: β = 0.09, P = 0.007)]. Participants with sarcopenia had a significantly lower PhA compared with those without it (sarcopenia vs. non-sarcopenia: young male participants, 5.51 ± 0.41° vs. 6.25 ± 0.50°, P < 0.001; young female participants, 4.88 ± 0.16° vs. 5.37 ± 0.44°, P = 0.005; elderly female participants: 4.14 ± 0.29° vs. 4.63 ± 0.42°, P = 0.009). Although no significant findings were observed in elderly male participants, the same tendency was noted. Receiver operating characteristic (ROC) curve analysis indicated that PhA had good predictive ability for sarcopenia in young male, elderly male, young female, and elderly female participants (area under the ROC curve of 0.882, 0.838, 0.865, and 0.850, with cut-off PhA values of 5.95°, 5.04°, 5.02°, and 4.20° for predicting sarcopenia, respectively).

CONCLUSIONS

The PhA reflected muscle quality and exhibited good accuracy in detecting sarcopenia, suggesting its utility as an index for easily measuring muscle quality, which could improve the diagnosis of sarcopenia.

Aging, Osteo-Sarcopenia, and Musculoskeletal Mechano-Transduction

The decline in the mass and function of bone and muscle is an inevitable consequence of healthy aging with early onset and accelerated decline in those with chronic disease. Termed osteo-sarcopenia, this condition predisposes the decreased activity, falls, low-energy fractures, and increased risk of co-morbid disease that leads to musculoskeletal frailty. The biology of osteo-sarcopenia is most understood in the context of systemic neuro-endocrine and immune/inflammatory alterations that drive inflammation, oxidative stress, reduced autophagy, and cellular senescence in the bone and muscle. Here we integrate these concepts to our growing understanding of how bone and muscle senses, responds and adapts to mechanical load. We propose that age-related alterations in cytoskeletal mechanics alter load-sensing and mechano-transduction in bone osteocytes and muscle fibers which underscores osteo-sarcopenia. Lastly, we examine the evidence for exercise as an effective countermeasure to osteo-sarcopenia.

INERTIA: A pilot study of the impact of progressive resistance training on blood pressure control in older adults with sarcopenia

Sarcopenia, and high blood pressure are highly prevalent, preventable conditions that pose significant burden for older adults and on the healthcare system. Current prevention and treatment of high blood pressure in sarcopenia, by non-pharmacological approaches remain limited and are far from optimal. Clinical trials and mechanistic studies provide encouraging evidence of a plausible therapeutic effect of progressive resistance training (PRT) on blood pressure in younger, and pre-hypertensive and hypertensive older adults. The impact of PRT on blood pressure has not been empirically tested in older adults with sarcopenia. This pilot study aims to provide effect size confidence intervals, clinical trial and intervention feasibility data, and procedural materials for a full-scale randomized controlled trial that will determine the efficacy of PRT intervention as a therapeutic strategy for blood pressure control in older adults with sarcopenia. Participants (N = 90) will be randomized to receive exercise educational materials or the PRT intervention consisting of 24 supervised exercise sessions over 12-weeks. Follow-up assessments will occur at 12-weeks and one-year later. The primary outcome is systolic blood pressure and diastolic blood pressure, analyzed separately. Microvascular mechanisms linking muscle (perfusion, strength, function) to changes in blood pressure will be explored at baseline and 12-weeks. This study will provide new evidence for the therapeutic effect of PRT as a non-pharmacological strategy for improving blood pressure. Insights gained may also inform of the potential role of muscle strength as a novel target for blood pressure control, and future exercise prescription guidelines related to muscle strengthening in high-risk older adults.

Frailty Status and Patient-Reported Outcomes in Octogenarians Following Transcatheter or Surgical Aortic Valve Replacement

BACKGROUND

Frailty status and patient-reported outcomes are especially pertinent in octogenarians following transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) to guide treatment decisions and promote patient-centred care.

AIM

We aimed to determine if frailty changed 6 months after aortic valve replacement (AVR) in octogenarians, and to describe changes in self-rated health according to frailty status in patients who underwent TAVI or SAVR.

METHOD

In a prospective cohort study, frailty and self-rated health were measured one day prior to and 6 months after AVR. Frailty status was measured with the Study of Osteoporotic Fracture index. Self-rated health was measured comprehensively with the disease-specific Minnesota Living with Heart Failure Questionnaire, the generic Medical Outcomes Study Short Form-12 questionnaire (SF-12), and two global questions from The World Health Organization Quality of Life Instrument Abbreviated.

RESULTS

Data were available for 143 consecutive patients (mean age 83±2.7 years, 57% women; 45% underwent TAVI). At baseline, 34% were robust, 27% prefrail, and 39% frail. Overall, there was no change in the distribution of frailty status 6 months after baseline (p=0.13). However, on an individual level 65 patients changed frailty status after AVR (40 patients improved and 25 declined). Improvement in frailty status was common in prefrail (33%; n=13) and frail patients (48%; n=27). Patients had improved self-rated health after AVR, with significant differences between frailty states both at baseline (SF-12 physical: 37.4 [robust], 33.1 [prefrail], 31.6 [frail], p=0.03); SF-12 mental: 51.9 [robust], 50.8 [prefrail], 44.5 [frail], p<0.001); and at the 6-month follow-up (SF-12 physical: 45.4 [robust], 38.3 [prefrail], 32.1 [frail], p<0.001); SF-12 mental: 54.9 [robust], 49.6 [prefrail], 46.8 [frail], p=0.002).

CONCLUSIONS

Advanced treatment performed in a high-risk population allowed people to improve their self-rated health. Although frailty is associated with poor self-rated health, frailty status does not equal negative outcomes. The frail patients were those who improved most in self-rated physical and mental health. They had the lowest baseline self-rated health scores and had therefore the most to gain.

Randomised controlled trial protocol for the PROTECT-CS Study: PROTein to Enhance outComes of (pre)frail paTients undergoing Cardiac Surgery

INTRODUCTION

In the past 20 years, the increasing burden of heart disease in an ageing population has resulted in cardiac surgery (CS) being offered to more frail and older patients with multiple comorbidities. Frailty and malnutrition are key geriatric syndromes that impact postoperative outcomes, including morbidity, mortality and prolonged hospital length of stay. Enhanced recovery protocols (ERPs), such as prehabilitation, have been associated with a reduction in complications after CS in vulnerable patients. The use of nutritional ERPs may enhance short-term and long-term recovery and mitigate frailty progression while improving patient-reported outcomes.

METHODS AND ANALYSIS

This trial is a two-centre, double-blinded, placebo, randomised controlled trial with blinded endpoint assessment and intention-to-treat analysis. One-hundred and fifty CS patients will be randomised to receive either a leucine-rich protein supplement or a placebo with no supplemented protein. Patients will consume their assigned supplement two times per day for approximately 2 weeks pre-procedure, during in-hospital postoperative recovery and for 8 weeks following discharge. The primary outcome will be the Short Physical Performance Battery score. Data collection will occur at four time points including baseline, in-hospital (pre-discharge), 2-month and 6-month time points post-surgery.

ETHICS AND DISSEMINATION

The University of Manitoba Biomedical Research Ethics Board (20 March 2018) and the St Boniface Hospital Research Review Committee (28 June 2019) approved the trial protocol for the primary site in Winnipeg, Manitoba, Canada. The second site's (Montreal, Quebec) ethics has been submitted and pending approval from the Research Ethics and New Technology Development Committee for the Montreal Heart Institute (December 2020). Recruitment for the primary site started February 2020 and the second site will begin January 2021. Data gathered from the PROTein to Enhance outComes of (pre)frail paTients undergoing Cardiac Surgery Study will be published in peer-reviewed journals and presented at national and international conferences. Knowledge translation strategies will be created to share findings with stakeholders who are positioned to implement evidence-informed change.

POTENTIAL STUDY IMPACT

Malnutrition and frailty play a crucial role in post-CS recovery. Nutritional ERPs are increasingly being recognised as a clinically relevant aspect of perioperative care. As such, this trial is to determine if leucine-rich protein supplementation at key intervals can mitigate frailty progression and facilitate enhanced postoperative recovery.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04038294).

Human T-cell lymphotropic virus type-1 infection associated with sarcopenia: community-based cross-sectional study in Goto, Japan

Sarcopenia is characterized by a progressive skeletal muscle disorder that involves the loss of muscle mass and low muscle strength, which contributes to increased adverse outcomes. Few studies have investigated the association between chronic infection and sarcopenia. This study aimed to examine the association between human T-cell lymphotropic virus type-1 (HTLV-1) and sarcopenia. We conducted a cross-sectional study and enrolled 2,811 participants aged ≥ 40 years from a prospective cohort study in Japanese community dwellers during 2017-2019. Sarcopenia was defined as low appendicular skeletal muscle mass and low handgrip strength. The association between HTLV-1 seropositivity and sarcopenia was assessed using multivariable logistic regression. Odds ratio (OR) and 95% confidence interval (CI) of sarcopenia were analysed using HTLV-1 seropositivity. We adjusted for age, sex, body mass index, physical activity, systolic blood pressure, glycated haemoglobin, low-density lipoprotein cholesterol, and smoking and drinking status. Of 2,811 participants, 484 (17.2%) HTLV-1 infected participants were detected. HTLV-1 infection was significantly associated with sarcopenia (adjusted OR 1.46, 95% CI 1.03-2.07, P = 0.034). HTLV-1 was associated with sarcopenia among community-dwelling adults. Active surveillance and early detection of asymptomatic HTLV-1 infection might be beneficial to reinforce countermeasures to inhibit the progress of HTLV infection-associated sarcopenia.

Body Mass Dynamics Is Determined by the Metabolic Ohm's Law and Adipocyte-Autonomous Fat Mass Homeostasis

An ODE model integrating metabolic mechanisms with clinical data reveals an Ohm's law governing lifetime body mass dynamics, where fat and lean tissues are analogous to a parallel nonlinear capacitor and resistor, respectively. The law unexpectedly decouples weight stability (a cell-autonomous property of adipocytes) and weight change (a parabolic trajectory governed by Ohm's law). In middle age, insulin resistance causes fat accumulation to avoid excessive body shrinkage in old age. Moderate middle-age spread is thus natural, not an anomaly caused by hypothalamic defects, as proposed by lipostatic theory. These discoveries provide valuable insights into health care practices such as weight control and health assessment, explain certain observed phenomena, make testable predictions, and may help to resolve major conundrums in the field. The ODE model, which is more comprehensive than Ohm's law, is useful to study metabolism at the detailed microscopic levels.

Increased Single-Fiber Jitter Level Is Associated With Reduction in Motor Function With Aging

OBJECTIVE

Age-associated skeletal muscle weakness is a major contributing factor to an increased late life mortality and morbidity, but its neurobiology is poorly understood. Previously, we provided histological evidence of dying-back axonal degeneration of motor neurons and denervation of neuromuscular junctions in age-associated muscle weakness. Given this, we aimed to evaluate the relation between impaired neuromuscular transmission and various aspects of age-associated muscle weakness.

DESIGN

We compared two electrophysiological measures, single-fiber jitter and compound motor action potential in mice of different age groups, and correlated them with various physical performance measures, such as grip strength, standing and walking time, and treadmill performance.

RESULTS

Consistent with our previous histological data, single-fiber jitter, a measure of neuromuscular junction transmission, was significantly increased in older animals, whereas compound motor action potential shows no difference between young and old age groups. Neither jitter nor compound motor action potential correlated with any of physical performance measures, except for jitter and standing activity.

CONCLUSIONS

Impaired neuromuscular transmission-represented as increase in single-fiber electromyography jitter level-reflects decline in motor function with aging.

Sarcopenia

Sarcopenia is a progressive and generalised skeletal muscle disorder involving the accelerated loss of muscle mass and function that is associated with increased adverse outcomes including falls, functional decline, frailty, and mortality. It occurs commonly as an age-related process in older people, influenced not only by contemporaneous risk factors, but also by genetic and lifestyle factors operating across the life course. It can also occur in mid-life in association with a range of conditions. Sarcopenia has become the focus of intense research aiming to translate current knowledge about its pathophysiology into improved diagnosis and treatment, with particular interest in the development of biomarkers, nutritional interventions, and drugs to augment the beneficial effects of resistance exercise. Designing effective preventive strategies that people can apply during their lifetime is of primary concern. Diagnosis, treatment, and prevention of sarcopenia is likely to become part of routine clinical practice.

Muscle Mass, Quality, and Composition Changes During Atrophy and Sarcopenia

Skeletal muscle mass (SMM) and muscle strengh reach their peak in 20s to 40s of age in human life and then decrease with advancing age. The decrease rate of muscle strength or power was twice to four times as large as that of the SMM. Thus, the normalized muscle force (muscle strength divided by SMM) also decreases in aging. It depends on the number of factors in skeletal muscle tissues and neuromuscular system. In human study, SMM cannot be measured directly without dissection so that all of the methodologies are indirect methods to assess SMM, even computing tomography or magnetic resonance imaging. Dual-energy X-ray absorptiometry, ultrasonography, anthropometry, and bioelectrical impedance analysis (BIA) are used as secondary indirect methods to estimate SMM. Recent researches show muscle composition changes in aging, and in particular, the ratio of muscle cell mass (MCM) against SMM decrease and relative expansion of extracellular water (ECW) and extracellular space is observed with advancing age and/or decrease of physical function. The intracellular water (ICW) and ECW estimated by segmental bioelectrical impedance spectroscopy or multifrequency BIA are good biomarkers of the ratio of MCM against SMM in limbs. The BIS and other state-of-the-art technology for assessment of muscle mass, quality, and composition are useful to fully understand the muscle atrophy in a living organism.

Physical activity interventions are delivered consistently across hospitalized older adults but multimorbidity is associated with poorer rehabilitation outcomes: A population-based cohort study

BACKGROUND

Older adults live with multimorbidity including frailty and cognitive impairment often requiring hospitalization. While physical activity interventions (PAIs) are a normal rehabilitative treatment, their clinical effect in hospitalized older adults is uncertain.

OBJECTIVE

To observe PAI dosing characteristics and determine their impact on clinical performance parameters.

DESIGN

A single-site prospective observational cohort study in an older persons' unit.

SUBJECTS

Seventy-five older persons' unit patients ≥65 years.

INTERVENTION

PAI; therapeutic contact between physiotherapy clinician and patient.

MEASUREMENTS

Parameters included changes in activities-of-daily-living (Barthel Index), handgrip strength, balance confidence, and gait velocity, measured between admission and discharge (episode). Dosing characteristics were PAI temporal initiation, frequency, and duration. Frailty/cognition status was dichotomized independently per participant yielding 4 subgroups: frail/nonfrail and cognitively-impaired/cognitively-unimpaired.

RESULTS

Median (interquartile range) PAI initiation occurred after 2 days (1-4), frequency was 0.4 PAIs per day (0.3-0.5), and PAI duration per episode was 3.75 hours (1.8-7.2). All clinical parameters improved significantly across episodes: grip strength median (interquartile range) change, 2.0 kg (0.0-2.3) (P < .01); Barthel Index, 5 (3-8) (P < .01); gait velocity, 0.06 m.∙s^-1 (0.06-0.16) (P < .01); and balance confidence, -3 (-6 to -1) (P < .01). Physical activity intervention dosing remained consistent within subgroups. While several moderate to large associations between amount of PAIs and change in clinical parameters were observed, most were within unimpaired subgroups.

CONCLUSIONS

PAI dosing is consistent. However, while clinical changes during hospital episodes are positive, more favourable responses to PAIs occur if patients are nonfrail/cognitively-unimpaired. Therefore, to deliver a personalized rehabilitation approach, adaptation of PAI dose based on patient presentation is desirable.

Early body composition, but not body mass, is associated with future accelerated decline in muscle quality

BACKGROUND

Muscle quality (MQ) or strength-to-mass ratio declines with aging, but the rate of MQ change with aging is highly heterogeneous across individuals. The identification of risk factors for accelerated MQ decline may offer clues to identity the underpinning physiological mechanisms and indicate targets for prevention and treatment. Using data from the Baltimore Longitudinal Study of Aging, we tested whether measures of body mass and body composition are associated with differential rates of changes in MQ with aging.

METHODS

Participants included 511 men and women, aged 50 years or older, followed for an average of 4 years (range: 1-8). MQ was operationalized as ratio between knee-extension isokinetic strength and CT-thigh muscle cross-sectional area. Predictors included body mass and body composition measures: weight (kg), body mass index (BMI, kg/m² ), dual-energy x-ray absorptiometry-measured total body fat mass (TFM, kg) and lean mass (TLM, kg), and body fatness (TFM/weight). Covariates were baseline age, sex, race, and body height.

RESULTS

Muscle quality showed a significant linear decline over the time of the follow up (average rate of decline 0.02 Nm/cm² per year, P < .001). Independent of covariates, neither baseline body weight (P = .756) nor BMI (P = .777) was predictive of longitudinal rate of decline in MQ. Instead, higher TFM and lower TLM at baseline predicted steeper longitudinal decline in MQ (P = .036 and P < .001, respectively). In particular, participants with both high TFM and low TLM at baseline experienced the most dramatic decline compared with those with low TFM and high TLM (about 3% per year vs. 0.5% per year, respectively). Participants in the higher tertile of baseline body fatness presented a significantly faster decline of MQ than the rest of the population (P = .021). Similar results were observed when body mass, TFM, and TLM were modeled as time-dependent predictors.

CONCLUSIONS

Body composition, but not weight nor BMI, is associated with future MQ decline, suggesting that preventive strategies aimed at maintaining good MQ with aging should specifically target body composition features.

The Need for Standardized Assessment of Muscle Quality in Skeletal Muscle Function Deficit and Other Aging-Related Muscle Dysfunctions: A Symposium Report

A growing body of scientific literature suggests that not only changes in skeletal muscle mass, but also other factors underpinning muscle quality, play a role in the decline in skeletal muscle function and impaired mobility associated with aging. A symposium on muscle quality and the need for standardized assessment was held on April 28, 2016 at the International Conference on Frailty and Sarcopenia Research in Philadelphia, Pennsylvania. The purpose of this symposium was to provide a venue for basic science and clinical researchers and expert clinicians to discuss muscle quality in the context of skeletal muscle function deficit and other aging-related muscle dysfunctions. The present article provides an expanded introduction concerning the emerging definitions of muscle quality and a potential framework for scientific inquiry within the field. Changes in muscle tissue composition, based on excessive levels of inter- and intra-muscular adipose tissue and intramyocellular lipids, have been found to adversely impact metabolism and peak force generation. However, methods to easily and rapidly assess muscle tissue composition in multiple clinical settings and with minimal patient burden are needed. Diagnostic ultrasound and other assessment methods continue to be developed for characterizing muscle pathology, and enhanced sonography using sensors to provide user feedback and improve reliability is currently the subject of ongoing investigation and development. In addition, measures of relative muscle force such as specific force or grip strength adjusted for body size have been proposed as methods to assess changes in muscle quality. Furthermore, performance-based assessments of muscle power via timed tests of function and body size estimates, are associated with lower extremity muscle strength may be responsive to age-related changes in muscle quality. Future aims include reaching consensus on the definition and standardized assessments of muscle quality, and providing recommendations to address critical clinical and technology research gaps within the field.

Frailty and sarcopenia: From theory to clinical implementation and public health relevance

The sustainability of healthcare systems is threatened by the increasing (absolute and relative) number of older persons referring to clinical services. Such global phenomenon is questioning the traditional paradigms of medicine, pushing towards the need of new criteria at the basis of clinical decision algorithms. In this context, frailty has been advocated as a geriatric condition potentially capable of overcoming the weakness of chronological age in the identification of individuals requiring adapted care due to their increased vulnerability to stressors. Interestingly, frailty poses itself beyond the concept of nosological conditions due to the difficulties at correctly framing traditional diseases in the complex and heterogeneous scenario of elders. Thus, frailty may play a key role in public health policies for promoting integrated care towards biologically aged individuals, currently presenting multiple unmet clinical needs. At the same time, the term frailty has also been frequently used in the literature for framing a physical condition of risk for (mainly functional) negative endpoints. The combination of such physical impairment with an organ-specific phenotype (e.g., the age-related skeletal muscle decline or sarcopenia) may determine the assumptions for the development of a clinical condition to be used as potential target for ad hoc interventions against physical disability. In the present article, we present the background of frailty and sarcopenia, and discuss their potentialities for reshaping current clinical and research practice in order to promote holistic approach to older patients, solicit personalization of care, and develop new targets for innovative interventions.

Assessment of muscle mass, risk of falls and fear of falling in elderly people with diabetic neuropathy

Abstract Objective : To assess muscle mass, risk of falls and fear of falling in elderly adults with diabetic neuropathy (DNP). Methods : 50 elderly patients with diabetes mellitus (DM) and diabetic neuropathy (NPD) participated in this study. Risk of falling was assessed using the Berg Balance Scale (BBS). Fear of falling was assessed by means of the Falls Efficacy Scale-International (FES-I). Muscle mass was assessed by tetrapolar bioimpedance analysis (BIA) and Janssen's equation. Subjects were divided into two groups: one with a history of falls in the six months before study enrollment (G1) and the other without history of falls (G2). Results : There were statistically significant differences between G1 and G2 regarding lean body mass (p < 0.05), risk of falls as measured by the BBS (p < 0.01), and fear of falling as measured by the FES-I (p < 0.01). In addition, there was a significant correlation between the BBS and BIA (r = 0.45 and p < 0.01), showing that the greater the lean body mass, the lower the risk of falling. Conclusions : We found an association between lean mass, risk of falls and fear of falling in elderly adults with DNP and a history of falls from own height.

Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia

Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM) to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.

Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ± 20.9 years; BMI: 23.8, interquartile range: 8.5). Dual energy X-ray absorptiometry (DXA) and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht²), and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m² determined participant assignment into the Normal LBM and Low LBM subgroups.

Results: The selected LBM predictor variables were body mass index (BMI), ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht² (adj. R² = 0.61, p < 0.001), the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R² = 0.85, p < 0.001). Scaled peak force was associated with age and echogenicity (adj. R² = 0.53, p < 0.001), but not LBM. The Low LBM subgroup of women (n = 10) had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < 0.05).

Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht² in women. In addition, ultrasound proxy measures of muscle quality are more strongly associated with strength than muscle mass within the study sample.

Translational geroscience: emphasizing function to achieve optimal longevity

Among individuals, biological aging leads to cellular and organismal dysfunction and an increased risk of chronic degenerative diseases and disability. This sequence of events in combination with the projected increases in the number of older adults will result in a worldwide healthcare burden with dire consequences. Superimposed on this setting are the adults now reaching traditional retirement ages--the baby boomers--a group that wishes to remain active, productive and physically and cognitively fit as they grow older. Together, these conditions are producing an unprecedented demand for increased healthspan or what might be termed “optimal longevity”—to live long, but well. To meet this demand, investigators with interests in the biological aspects of aging from model organisms to human epidemiology (population aging) must work together within an interactive process that we describe as translational geroscience. An essential goal of this new investigational platform should be the optimization and preservation of physiological function throughout the lifespan, including integrative physical and cognitive function, which would serve to increase healthspan, compress morbidity and disability into a shorter period of late-life, and help achieve optimal longevity. To most effectively utilize this new approach, we must rethink how investigators and administrators working at different levels of the translational research continuum communicate and collaborate with each other, how best to train the next generation of scientists in this new field, and how contemporary biological-biomedical aging research should be organized and funded.

The Neuromuscular Junction: Aging at the Crossroad between Nerves and Muscle

Aging is associated with a progressive loss of muscle mass and strength and a decline in neurophysiological functions. Age-related neuromuscular junction (NMJ) plays a key role in musculoskeletal impairment that occurs with aging. However, whether changes in the NMJ precede or follow the decline of muscle mass and strength remains unresolved. Many factors such as mitochondrial dysfunction, oxidative stress, inflammation, changes in the innervation of muscle fibers, and mechanical properties of the motor units probably perform an important role in NMJ degeneration and muscle mass and strength decline in late life. This review addresses the primary events that might lead to NMJ dysfunction with aging, including studies on biomarkers, signaling pathways, and animal models. Interventions such as caloric restriction and exercise may positively affect the NMJ through this mechanism and attenuate the age-related progressive impairment in motor function.

The role of dietary protein and vitamin D in maintaining musculoskeletal health in postmenopausal women: a consensus statement from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO)

From 50 years of age, postmenopausal women are at an increased risk of developing sarcopenia and osteoporosis as a result of deterioration of musculoskeletal health. Both disorders increase the risk of falls and fractures. The risk of developing sarcopenia and osteoporosis may be attenuated through healthy lifestyle changes, which include adequate dietary protein, calcium and vitamin D intakes, and regular physical activity/exercise, besides hormone replacement therapy when appropriate. Protein intake and physical activity are the main anabolic stimuli for muscle protein synthesis. Exercise training leads to increased muscle mass and strength, and the combination of optimal protein intake and exercise produces a greater degree of muscle protein accretion than either intervention alone. Similarly, adequate dietary protein intake and resistance exercise are important contributors to the maintenance of bone strength. Vitamin D helps to maintain muscle mass and strength as well as bone health. These findings suggest that healthy lifestyle measures in women aged >50 years are essential to allow healthy ageing. The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) recommends optimal dietary protein intake of 1.0-1.2g/kgbodyweight/d with at least 20-25g of high-quality protein at each main meal, with adequate vitamin D intake at 800IU/d to maintain serum 25-hydroxyvitamin D levels >50nmol/L as well as calcium intake of 1000mg/d, alongside regular physical activity/exercise 3-5 times/week combined with protein intake in close proximity to exercise, in postmenopausal women for prevention of age-related deterioration of musculoskeletal health.

What's in a name revisited: should osteoporosis and sarcopenia be considered components of "dysmobility syndrome?"

Sarcopenia and osteoporosis are age-related declines in the quantity and quality of muscle and bone respectively, with shared pathogeneses and adverse health consequences. Both absolute and relative fat excess, i.e., obesity and sarcopenic obesity, contribute to disability, falls, and fractures. Rather than focusing on a single component, i.e., osteoporosis, sarcopenia, or obesity, we realized that an opportunity exists to combine clinical factors, thereby potentially allowing improved identification of older adults at risk for disability, falls, and fractures. Such a combination could be termed dysmobility syndrome, analogous to the approach taken with metabolic syndrome. An arbitrary score-based approach to dysmobility syndrome diagnosis is proposed and explored in a small cohort of older adults. Further evaluation of such an approach in large population-based and prospective studies seems warranted.

[Translational research in geriatrics? A plea based on current biomedical key publications]

Contemporary geriatric research focuses mainly on observational clinical studies and epidemiological surveys and the translation of basic scientific results from biogerontology into a clinical context is often neglected. Following a definition of translational research the article gives an overview of recent key publications in experimental biogerontology with a special emphasis on their relevance for clinical geriatrics. The topics dealt with include age-induced loss of skeletal muscle (sarcopenia), the aging immune system (immunosenescence) and neurodegenerative disorders (Alzheimer's and Parkinson's disease).

Sarcopenia in older adults

PURPOSE OF REVIEW

Sarcopenia, or the decline of skeletal muscle tissue with age, is one of the most important causes of functional decline and loss of independence in older adults. The purpose of this article is to review the current definitions of sarcopenia, its potential causes and clinical consequences, and the potential for intervention.

RECENT FINDINGS

Although no consensus diagnosis has been reached, sarcopenia is increasingly defined by both loss of muscle mass and loss of muscle function or strength. Its cause is widely regarded as multifactorial, with neurological decline, hormonal changes, inflammatory pathway activation, declines in activity, chronic illness, fatty infiltration, and poor nutrition, all shown to be contributing factors. Recent molecular findings related to apoptosis, mitochondrial decline, and the angiotensin system in skeletal muscle have highlighted biological mechanisms that may be contributory. Interventions in general continue to target nutrition and exercise.

SUMMARY

Efforts to develop a consensus definition are ongoing and will greatly facilitate the development and testing of novel interventions for sarcopenia. Although pharmaceutical agents targeting multiple biological pathways are being developed, adequate nutrition and targeted exercise remain the gold standard for therapy.