Sarcopenia and dynapenia is correlated to worse quality of life perception in middle-aged and older adults with Parkinson's disease

BACKGROUND

There are few studies that assess the relationship between nutritional status and quality of life in individuals with Parkinson's disease, despite the well-established negative impact of sarcopenia and dynapenia on functional capacity and quality of life. These conditions impair protein-muscular status and are prevalent in individuals with Parkinson's disease. This study aimed to examine the relationship between nutritional status, including body composition, functional capacity, and diagnosis of sarcopenia and dynapenia, and quality-of-life perception in individuals with Parkinson's disease.

METHODS

This is a cross-sectional study conducted in two Parkinson's disease centers in the northeast of Brazil. The researchers assessed muscle strength, muscle mass, and physical performance to diagnose dynapenia, sarcopenia and functional capacity. Quality of life was estimated using the Parkinson's disease Quality of Life Questionnaire.

RESULTS

We found positive correlations between quality of life and variables such as severity and duration of the disease, as well as positive screening for sarcopenia (p<0.001). Negative correlations were observed between quality of life and muscle strength and functional capacity. The study also found that individuals with sarcopenia and dynapenia had significantly worse quality-of-life scores compared to those who did not have these nutritional outcomes (p <0.05; p <0.001).

CONCLUSIONS

The presence of sarcopenia, dynapenia, low gait speed, disease duration, and severity had an impact on higher scores in the Parkinson's Disease Quality of Life Questionnaire, indicating a worsening perception of quality of life.

Association between bone health and dynapenic obesity in postmenopausal women

AIM

The combination of dynapenia (age-related muscle weakness) and obesity is referred to as dynapenic obesity. We examined the associations between dynapenic obesity and cortical bone thickness and trabecular bone density.

METHODS

The participants were 797 community-dwelling postmenopausal women (with an average age of 62.5 years) who were stratified into normopenia without obesity, dynapenia without obesity (dynapenia), normopenia with obesity (obesity) and dynapenia with obesity (dynapenia obesity) groups based on their grip strength and body fat percentage. Cortical bone thickness and trabecular bone density were measured using ultrasonic bone densitometry. The participants were further divided into those with low cortical bone thickness and low trabecular bone density. Logistic regression analysis was used to identify associated factors.

RESULTS

Individuals with dynapenia (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.16-2.68), obesity (OR 2.46, 95% CI 1.62-3.75) and dynapenic obesity (OR 4.07, 95% CI 2.44-6.79) all significantly increased the odds of low cortical bone thickness. Conversely, the odds of low trabecular bone density were significantly lower in the obesity group (OR 0.65, 95% CI 0.43-0.99) and dynapenic obesity group (OR 0.60, 95% CI 0.37-0.97).

CONCLUSIONS

Dynapenic obesity was found to be associated with cortical bone thinning that might compromise bone health. Postmenopausal women with dynapenic obesity might need to be closely monitored for preserving bone health. Geriatr Gerontol Int 2024; 24: 378-384.

Assessing muscular power in older adults: evaluating the predictive capacity of the 30-second chair rise test

Background: Timed chair rise tests are frequently used as a substitute for assessing leg muscle strength or power. To determine if timed chair rise tests are an indicator of lower extremity muscle power, we examined the relationship between the repetitions completed in a 30-s chair rise test and the power generated during the test. Methods: Seventy-five individuals participated in this study (n = 30 < 65 years and 45 ≥ 65 years). Participants underwent a 30-s chair rise test while instrumented with a power analyzer. Handgrip strength was also evaluated. Results: The relationship between chair rise repetitions and average chair rise power was R 2 = 0.32 (p < 0.001). Chair rise repetitions when regressed on a total (i.e., summed) chair rise power, it yielded R 2 = 0.70 with data from all participants combined (p < 0.001). A mediation analysis indicated that anthropometrics partially mediates the relationship between chair rise repetitions and total chair rise power accounting for 2.8%-6.9% of the variance. Conclusion: Our findings indicate that in older adults, the overall performance of chair rises offers limited information about the average power per rise but is more indicative of the cumulative power exerted. Thus, the total number of chair rises in a 30-s test is likely a more comprehensive metric of overall muscular power, reflecting endurance aspects as well. Additionally, we found that personal physical attributes, such as height and weight, partially influence the link between chair rise count and total power, highlighting the importance of factoring in individual body metrics in assessments of muscular performance.

Association between dynapenia and cognitive decline in community-dwelling older Japanese adults: The IRIDE Cohort Study

AIM

Muscle mass and strength correlate with cognitive function; however, it remains unclear whether dynapenia (i.e., muscle weakness with preserved muscle mass) is relevant. This study aimed to explore whether dynapenia is associated with global cognitive function in community-dwelling older Japanese adults.

METHODS

This cross-sectional study used data from the Integrated Research Initiative for Living Well with Dementia Cohort Study, which pooled data from five community-based geriatric cohorts. Dynapenia was defined as muscle weakness without muscle mass loss according to the Asian Working Group for Sarcopenia criteria. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). An ordered logistic regression analysis was conducted with dynapenia as the exposure and with cognitive decline stages, defined as an MMSE score of 27-30 for normal cognition, 24-26 for possible cognitive decline, and <24 for cognitive decline, as the outcome, stratified by sex and adjusted for age, muscle mass, education, alcohol consumption, smoking habits, living alone, and non-communicable diseases.

RESULTS

We analyzed data for 3338 participants (2162 female) with preserved muscle mass. Of these, 449 (13.5%) had dynapenia, and 79 (2.4%) exhibited cognitive decline. Multivariate odds ratios (95% confidence interval) for cognitive decline among those with dynapenia, compared with those without dynapenia, were 1.51 (1.02-2.24) for males and 2.08 (1.51-2.86) for females.

CONCLUSIONS

Muscle weakness is associated with cognitive decline, even in individuals with preserved muscle mass. Further studies are needed to better understand the association between muscle weakness and cognitive decline over time in order to develop dementia prevention strategies for those with dynapenia. Geriatr Gerontol Int 2024; 24: 123-129.

Relationship between Eating Alone and Handgrip Strength in Korean Older Adults

Sarcopenia is defined as an age-related decline in muscle mass, muscle strength, and physical performance. Eating alone has been linked to various health issues in older adults. This study investigated the relationship between eating alone and handgrip strength (HGS) in older adults using data from 7278 individuals (≥65 years) who participated in the 2014-2019 Korea National Health and Nutrition Examination Survey. HGS was measured using a digital grip strength dynamometer, relative HGS was calculated by dividing HGS by body mass index, and dynapenia was defined as an HGS < 28 kg for men and <18 kg for women. Multivariable logistic regression analysis showed that women who ate two meals alone were more likely to exhibit dynapenia than those who never ate alone (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.03-1.77). If the groups that never ate alone or ate one meal alone were combined as the reference group, the probability of dynapenia was higher in the combined groups that ate two or three meals alone (OR, 1.25; 95% CI, 1.04-1.50). No association was observed between eating alone and dynapenia in men. This suggests that eating alone is a modifiable related factor of dynapenia in older women.

Associations of Dynapenic Abdominal Obesity and Frailty Progression: Evidence from Two Nationwide Cohorts

The associations of dynapenic abdominal obesity and transitions with frailty progression remain unclear among middle-aged and older adults. We included 6937 participants from the China Health and Retirement Longitudinal Study (CHARLS) and 3735 from the English Longitudinal Study of Aging (ELSA). Participants were divided into non-dynapenia and non-abdominal obesity (ND/NAO), abdominal obesity alone (AO), dynapenia alone (D), and dynapenic abdominal obesity (D/AO). Frailty status was assessed by the frailty index (FI), and a linear mixed-effect model was employed to analyze the associations of D, AO, D/AO, and transitions with frailty progression. Participants with AO, D, and D/AO had increased FI progression compared with ND/NAO in both cohorts. D/AO possessed the greatest additional annual FI increase of 0.383 (95% CI: 0.152 to 0.614), followed by D and AO in the CHARLS. Participants with D in the ELSA had the greatest magnitude of accelerated FI progression. Participants who transitioned from ND/NAO to D and from AO to D/AO presented accelerated FI progression in the CHARLS and ELSA. In conclusion, dynapenic abdominal obesity, especially for D/AO and D, presented accelerated frailty progression. Our findings highlighted the essential intervention targets of dynapenia and abdominal obesity for the prevention of frailty progression.

Precision MRI phenotyping of muscle volume and quality at a population scale

Introduction: Magnetic resonance imaging (MRI) enables direct measurements of muscle volume and quality, allowing for an in-depth understanding of their associations with anthropometric traits, and health conditions. However, it is unclear which muscle volume measurements: total muscle volume, regional measurements, measurements of muscle quality: intermuscular adipose tissue (IMAT) or proton density fat fraction (PDFF), are most informative and associate with relevant health conditions such as dynapenia and frailty. Methods: We have measured image-derived phenotypes (IDPs) including total and regional muscle volumes and measures of muscle quality, derived from the neck-to-knee Dixon images in 44,520 UK Biobank participants. We further segmented paraspinal muscle from 2D quantitative MRI to quantify muscle PDFF and iron concentration. We defined dynapenia based on grip strength below sex-specific cut-off points and frailty based on five criteria (weight loss, exhaustion, grip strength, low physical activity and slow walking pace). We used logistic regression to investigate the association between muscle volume and quality measurements and dynapenia and frailty. Results: Muscle volumes were significantly higher in male compared with female participants, even after correcting for height while, IMAT (corrected for muscle volume) and paraspinal muscle PDFF were significantly higher in female compared with male participants. From the overall cohort, 7.6% (N = 3,261) were identified with dynapenia, and 1.1% (N = 455) with frailty. Dynapenia and frailty were positively associated with age and negatively associated with physical activity levels. Additionally, reduced muscle volume and quality measurements were associated with both dynapenia and frailty. In dynapenia, muscle volume IDPs were most informative, particularly total muscle exhibiting odds ratios (OR) of 0.392, while for frailty, muscle quality was found to be most informative, in particular thigh IMAT volume indexed to height squared (OR = 1.396), both with p-values below the Bonferroni-corrected threshold (p < 8.8 × 10 - 5 ). Conclusion: Our fully automated method enables the quantification of muscle volumes and quality suitable for large population-based studies. For dynapenia, muscle volumes particularly those including greater body coverage such as total muscle are the most informative, whilst, for frailty, markers of muscle quality were the most informative IDPs. These results suggest that different measurements may have varying diagnostic values for different health conditions.

Dynapenic Abdominal Obesity and Metabolic Health in Non-Geriatric Patients with Obesity

Background: Dynapenic abdominal obesity (DAO) is the combination of low muscle strength and high central adiposity, which can lead to functional and cardiometabolic impairments. Objective: The aim of this study was to examine the relationship between DAO and metabolic parameters in non-geriatric patients with obesity. Methods: All patients seen in the obesity outpatient clinic during a random month, along with 30 healthy individuals, were included in the study. Body mass index (BMI), waist circumference (WC), hip circumference (HC), serum fasting blood glucose, triglyceride, high-density lipoprotein, low-density lipoprotein (LDL), insulin, and glycated hemoglobin (HbA1c) levels were measured. Muscle function tests were conducted. Hypertension and diabetes mellitus diagnoses were recorded. DAO was determined using handgrip strength and WC. Metabolic syndrome was defined based on International Diabetes Federation (IDF) criteria. Data were analyzed using SPSS. Results: A total of 106 individuals participated in the study, including 76 individuals with obesity as the case group and 30 healthy individuals as the control group. In the case group, BMI, WC, HC, and chair stand test results were higher compared to the control group. There was no significant difference between the case and control groups in terms of gait speed or handgrip test results. In the case group, 30 people (39.5%) had dynapenic obesity (DO), and in the control group, 8 people (26.7%) had DO. There was no significant difference in DO rates between the case and control groups. In the case group, the HbA1c level was higher in DO (+) group than DO (-) group. In the control group, DO (+) group had higher LDL and HbA1c level than DO (-) group. No significant difference was observed in other search parameters between the DO (+) and DO (-) groups in both the case and control groups. Conclusion: DAO is common among people with obesity and contributes to a poor prognosis, increased morbidity, and mortality. Therefore, including its treatment in the management of obesity is crucial for individuals of all age ranges.

Dynapenic Abdominal Obesity, Single and Recurrent Falls in Older Brazilian Adults: Elsi-Brazil Results

Objective: Cross-sectional study to verify the association between dynapenic abdominal obesity and the occurrence of single and recurrent falls among Brazilian adults aged 50 years and over. Methods: Baseline data from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), comprising 8374 individuals aged 50 years and over, were analyzed. Participants were categorized according to the report of falls, dynapenic abdominal obesity was determined by combining the presence of abdominal obesity (waist circumference) and dynapenia (handgrip strength). A multinomial regression adjusted for multiple variables was conducted. Results: The prevalence of a fall was 10.4% (95% CI: 9.7-11.2) and 10.8% for single and recurrent (95% CI: 9.9-11.9). Dynapenic abdominal obesity was associated with a single fall (OR: 1.3; 95% CI 1.1-1.7) and showed greater strength of association with recurrent falls (OR: 2.8; 95% CI 2.1-3.8). Conclusions: Our data showed that the coexistence of abdominal obesity and dynapenia in older adults creates additional challenges for aging.

Prevalence of Sarcopenia and Dynapenia and Related Clinical Outcomes in Patients with Type 1 Diabetes Mellitus

BACKGROUND

Sarcopenia has recently been recognized as a complication of diabetes. However, there are few results about the prevalence of sarcopenia and dynapenia and the related clinical outcomes in type 1 diabetes mellitus (T1DM). Our objectives were to evaluate the prevalence of sarcopenia and dynapenia and to determine whether there are any associations with disease-related factors in people with T1DM.

METHODS

A cross-sectional study was conducted in people with T1DM. We assessed appendicular skeletal mass index (ASMI) using bioimpedance 50 Hz (Nutrilab Akern). Muscle function was assessed through handgrip strength (HGS) using a Jamar dynamometer. Sarcopenia was defined as a low HGS with low ASMI, whereas dynapenia was defined as low HGS with a normal ASMI. We used HGS data from the Spanish population percentile table and a cut-off point at p5 as dynapenia. The association of clinical, metabolic, and lifestyle variables with sarcopenia and dynapenia was studied.

RESULTS

This study included 62 T1DM patients (66% females, mean age of 38 ± 14 years, body mass index (BMI) of 24.9 ± 4.7 kg/m2). The prevalence of sarcopenia and dynapenia was 8% and 23%, respectively. In our sample, there were more men in the sarcopenic and dynapenic groups. The sarcopenic group showed a significantly higher mean HbA1c value. Lower diabetes duration, PREDIMED score, BMI, and muscle mass measures (fat-free mass index (FFMI), ASMI, and body cell mass index (BCMI)) were significantly associated with sarcopenia. Decreased diabetes duration, PREDIMED score, phase angle (PhA), and HGS values showed a significant association with dynapenia.

CONCLUSIONS

The prevalence of sarcopenia and dynapenia was high in people with T1DM in our study. Specifically, the proportion of dynapenia was quite high. HGS and ASMI are practical tools for the assessment of muscle health status in T1DM, and low values are associated with poor glycemic control, underweight, and low adherence to the Mediterranean diet. Thus, dynapenia may predict accelerated muscle aging in T1DM.

Association between Chronic Kidney Disease and Dynapenia in Elderly Koreans

Chronic kidney disease (CKD) is caused by various factors such as chronic inflammation, oxidative stress, and obesity. Loss of muscle strength and mass is a negative prognostic factor for CKD. Therefore, in this study, we aimed to investigate the association between CKD and dynapenia in the Korean elderly. To this end, we analyzed 7029 participants from the 2014-2019 Korean National Health and Nutrition Examination Survey (KNHANES) aged ≥65 years. After adjusting for all of the covariates that could affect the results, such as physical examinations, lifestyle factors, and exercise, the association between CKD and dynapenia was found to be significant, at 1.207 (95% CI: 1.056-1.379) in CKD stage 2 and 1.790 (95% CI: 1.427-2.246) in CKD stage 3a-5. However, when sexes were analyzed separately, women were significant in both CKD stage 2 and stage 3-5 compared to normal, but only in stage 3-5 for men. Additionally, the prevalence of dynapenia increased significantly as the stage of CKD increased (normal, stage 2, and stage 3-5: 18.5%, 20.8%, and 32.3% in men and 27.5%, 34.4%, and 46.1% in women, respectively). Thus, CKD is significantly related to dynapenia, especially in women, when stratified by sex.

Dehydroepiandrosterone Sulfate, an Adrenal Androgen, Is Inversely Associated with Prevalence of Dynapenia in Male Individuals with Type 2 Diabetes

Dehydroepiandrosterone sulfate (DHEAS) is thought to be associated with life expectancy and anti-aging. Although skeletal muscle disorders are often found in diabetic people, the clinical significance of DHEAS in skeletal muscle remains unclear. Therefore, we aimed to determine whether DHEAS is associated with the development of skeletal muscle disorders in individuals with type 2 diabetes (T2D). A cross-sectional study was conducted in 361 individuals with T2D. Serum DHEAS levels, skeletal muscle mass index (SMI), handgrip strength (HS), and gait speed (GS) were measured in the participants. Pre-sarcopenia, sarcopenia, and dynapenia were defined according to the definitions of the AWGS 2019 criteria. DHEAS level was positively associated with HS but not with SMI or GS after adjustment of confounding factors. Multiple logistic regression analyses in total subjects showed that DHEAS level had an inverse association with the prevalence of dynapenia but not with the prevalence of pre-sarcopenia or sarcopenia. Furthermore, a significant association between DHEAS level and dynapenia was found in males but not in females. ROC curve analysis indicated that cutoff values of serum DHEAS for risk of dynapenia in males was 92.0 μg/dL. Therefore, in male individuals with T2D who have low serum levels of DHEAS, adequate exercise might be needed to prevent dynapenia.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A cross-sectional study of ageing at the mouse neuromuscular junction and effects of an experimental therapeutic approach for dynapenia

Despite prior efforts to understand and target dynapenia (age-induced loss of muscle strength), this condition remains a major challenge that reduces the quality of life in the aged population. We have focused on the neuromuscular junction (NMJ) where changes in structure and function have rarely been systematically studied as a dynamic and progressive process. Our cross-sectional study found neurotransmission at the male mouse NMJ to be biphasic, displaying an early increase followed by a later decrease, and this phenotype was associated with structural changes to the NMJ. A cross-sectional characterization showed that age-induced alterations fell into four age groups: young adult (3-6 months), adult (7-18 months), early aged (19-24 months), and later aged (25-30 months). We then utilized a small molecule therapeutic candidate, GV-58, applied acutely during the later aged stage to combat age-induced reductions in transmitter release by increasing calcium influx during an action potential, which resulted in a significant increase in transmitter release. This comprehensive study of neuromuscular ageing at the NMJ will enable future research to target critical time points for therapeutic intervention. KEY POINTS: Age-induced frailty and falls are the leading causes of injury-related death and are caused by an age-induced loss of muscle strength due to a combination of neurological and muscular changes. A cross-sectional approach was used to study age-induced changes to the neuromuscular junction in a mouse model, and physiological changes that were biphasic over the ageing time course were found. Changes in physiology at the neuromuscular junction were correlated with alterations in neuromuscular junction morphology. An acutely applied positive allosteric gating modifier of presynaptic voltage-gated calcium channels was tested as a candidate therapeutic strategy that could increase transmitter release at aged neuromuscular junctions. These results provide a detailed time course of age-induced changes at the neuromuscular junction in a mouse model and test a candidate therapeutic strategy for weakness.

Handgrip strength and risk of malnutrition are associated with an increased risk of hospitalizations in inflammatory bowel disease patients

Background

In patients with inflammatory bowel disease (IBD), frailty is independently associated with mortality and morbidity.

Objectives

This study aimed to extend this work to determine the association between the clinical frailty scale (CFS), handgrip strength (HGS), and malnutrition with IBD-related hospitalizations and surgeries.

Design

IBD patients ⩾18 years of age were prospectively enrolled from two ambulatory care clinics in Alberta, Canada.

Methods

Frailty was defined as a CFS score ⩾4, dynapenia as HGS < 16 kg for females and <27 kg for males, malnutrition using the subjective global assessment (SGA), and the risk of malnutrition using either the abridged patient-generated SGA (abPG-SGA), or the Saskatchewan Inflammatory Bowel Disease Nutrition Risk Tool (SaskIBD-NRT). Logarithm relative hazard graphs and multivariable logistic regression models adjusting for relevant confounders were constructed.

Results

One hundred sixty-one patients (35% ulcerative colitis, 65% Crohn's disease) with a mean age of 42.2 (±15.9) years were followed over a mean period of 43.9 (±10.1) months. Twenty-seven patients were hospitalized, and 13 patients underwent IBD-related surgeries following baseline. While the CFS (aHR 1.34; p = 0.61) and SGA (aHR 0.81; p = 0.69) did not independently predict IBD-related hospitalizations, decreased HGS (aHR 3.96; p = 0.03), increased abPG-SGA score (aHR 1.07; p = 0.03) and a SaskIBD-NRT ⩾ 5 (aHR 4.49; p = 0.02) did. No variable was independently associated with IBD-related surgeries.

Conclusion

HGS, the abPG-SGA, and the SaskIBD-NRT were independently associated with an increased risk of IBD-related hospitalizations. Future studies should aim to validate other frailty assessments in the IBD population in order to better tailor care for all IBD patients.

Emergence and Progression of Behavioral Motor Deficits and Skeletal Muscle Atrophy across the Adult Lifespan of the Rat

The facultative loss of muscle mass and function during aging (sarcopenia) poses a serious threat to our independence and health. When activities of daily living are impaired (clinical phase), it appears that the processes leading to sarcopenia have been ongoing in humans for decades (preclinical phase). Here, we examined the natural history of sarcopenia in male outbred rats to compare the occurrence of motor behavioral deficits with the degree of muscle wasting and to explore the muscle-associated processes of the preclinical and clinical phases, respectively. Selected metrics were validated in female rats. We used the soleus muscle because of its long duty cycles and its importance in postural control. Results show that gait and coordination remain intact through middle age (40-60% of median lifespan) when muscle mass is largely preserved relative to body weight. However, the muscle shows numerous signs of remodeling with a shift in myofiber-type composition toward type I. As fiber-type prevalence shifted, fiber-type clustering also increased. The number of hybrid fibers, myofibers with central nuclei, and fibers expressing embryonic myosin increased from being barely detectable to a significant number (5-10%) at late middle age. In parallel, TGFβ1, Smad3, FBXO32, and MuRF1 mRNAs increased. In early (25-month-old) and advanced (30-month-old) aging, gait and coordination deteriorate with the progressive loss of muscle mass. In late middle age and early aging due to type II atrophy (>50%) followed by type I atrophy (>50%), the number of myofibers did not correlate with this process. In advanced age, atrophy is accompanied by a decrease in SCs and βCatenin mRNA, whereas several previously upregulated transcripts were downregulated. The re-expression of embryonic myosin in myofibers and the upregulation of mRNAs encoding the γ-subunit of the nicotinic acetylcholine receptor, the neuronal cell adhesion molecule, and myogenin that begins in late middle age suggest that one mechanism driving sarcopenia is the disruption of neuromuscular connectivity. We conclude that sarcopenia in rats, as in humans, has a long preclinical phase in which muscle undergoes extensive remodeling to maintain muscle mass and function. At later time points, these adaptive mechanisms fail, and sarcopenia becomes clinically manifest.

Dynapenic abdominal obesity and susceptibility to fall: a prospective analysis of the Osteoarthritis Initiative

Background

The prediction of the risk of falling remains a challenge in geriatric medicine and the identification of new potential reversible risk factors is a public health priority. In this study, we aim to investigate the association between DAO (dynapenic abdominal obesity) and incident falls in a large sample of people with knee OA (osteoarthritis) or at high risk for this condition, over 8 years of follow-up.

Methods

DAO was defined using a waist circumference more than 102 cm in men and 88 cm in women and a concomitant presence of dynapenia, defined as a time over 15 s in the five times chair stands time. Falls, during follow-up, were recorded using self-reported information in the previous year. A logistic binary regression analysis was run, adjusted for potential confounders at the baseline, reporting the data as odds ratios (ORs) with their 95% confidence intervals (CIs).

Results

Overall, 3,844 subjects were included, majority of whom had abdominal obesity. Across the 8 years of follow-up, 2,695 participants fell vs. 1,149 not reporting any fall. Taking those without DAO as reference, the presence of only dynapenia was not associated with risk of falls (OR = 1.18;95%CI: 0.73-1.91; p = 0.50), whilst the presence of abdominal obesity (OR = 1.30; 95%CI: 1.09-1.56; p = 0.004) and DAO (OR = 1.31; 95%CI:1.01-1.73; p = 0.04) were significantly associated with a higher risk of incident falls.

Conclusion

DAO significantly increased risk of falls as well as the presence of abdominal obesity.

Prognostic value of liver damage assessed through direct bilirubin levels and skeletal muscle weakness in patients with heart failure

BACKGROUND

Patients with heart failure (HF) often exhibit signs of liver dysfunction such as high bilirubin concentrations, leading to physical dysfunction and poor prognosis. Nevertheless, the relationship between direct bilirubin (DB), a fractionated form of total bilirubin, and dynapenia remains unclear, as does their effect on prognosis.

OBJECTIVES

This study investigated the association between DB concentrations and dynapenia in patients with HF.

METHODS

This retrospective study included patients with HF who underwent assessments for DB concentration, and handgrip and leg strengths to evaluate dynapenia and muscle weakness, respectively. Multiple logistic regression analyses examined the associations of DB with muscle strength and dynapenia. Additionally, we examined the prognostic value of comorbid high DB concentrations (≥0.5 mg/dL) and dynapenia. The endpoint was all-cause mortality.

RESULTS

Of 853 inpatients, high DB was identified in 147 and dynapenia in 377 (44.2%). Multiple regression analysis revealed that high DB was independently associated with decreased muscle strength (handgrip strength, P = 0.027; leg strength, P = 0.002). After adjusting for covariates, the high DB group (odds ratio: 1.800, 95% confidence interval [CI]: 1.203-2.695, P = 0.004) had a significantly higher risk of dynapenia than the low DB group. During the follow-up period, 189 patients died (median, 1.77 years; interquartile range, 0.64-3.81 years). The risk of death was significantly higher in the high DB and dynapenia group, even after adjusting for HF severity (hazard ratio: 2.610, 95% CI: 1.680-4.051, P<0.001).

CONCLUSIONS

High DB is associated with muscle weakness, and when combined with dynapenia, DB predicts a poorer prognosis in patients with HF.

Examining Factors Associated with Dynapenia/Sarcopenia in Patients with Schizophrenia: A Pilot Case-Control Study

Sedentary behavior in patients with schizophrenia causes muscle weakness, is associated with a higher risk of metabolic syndrome, and contributes to mortality risk. This pilot case-control study aims to examine the associated factors for dynapenia/sarcopenia in patients with schizophrenia. The participants were 30 healthy individuals (healthy group) and 30 patients with schizophrenia (patient group), who were matched for age and sex. Descriptive statistics, Welch's t-test, cross-tabulations, adjusted residuals, Fisher's exact probability test (extended), and/or odds ratios (ORs) were calculated. In this study, dynapenia was significantly more prevalent in patients with schizophrenia than in healthy individuals. Regarding body water, Pearson's chi-square value was 4.41 (p = 0.04), and significantly more patients with dynapenia were below the normal range. In particular, body water and dynapenia showed a significant association, with an OR = 3.42 and 95% confidence interval [1.06, 11.09]. Notably, compared with participants of the healthy group, patients with schizophrenia were overweight, had less body water, and were at a higher risk for dynapenia. The impedance method and the digital grip dynamometer used in this study were simple and useful tools for evaluating muscle quality. To improve health conditions for patients with schizophrenia, additional attention should be paid to muscle weakness, nutritional status, and physical rehabilitation.

Dynapenia, Muscle Quality, and Hepatic Steatosis in Patients with Obesity and Sarcopenic Obesity

Accumulating evidence supports a connection between sarcopenic obesity (SO) and NAFLD. The extent to which fatty liver contributes to impaired muscle contractility is not yet well established. The aim of our study was to investigate the effect of NAFLD on dynapenia in patients with SO. In this study, 71 non-diabetic subjects (age 55 (7.8) years, BMI 35.2 kg/m² (32.6-38.8)) were classified as having SO and non-sarcopenic obesity (NSO). SO patients displayed worse serum lipid profiles, higher body fat, and lower skeletal muscle mass (both total and appendicular) than NSO patients, despite the absence of any significant differences in body weight, glycometabolic parameters, and hepatic steatosis prevalence. A positive correlation between disposition index and muscle quality index (MQI) (r = 0.393, p = 0.013) emerged after controlling for menopause and body fat percentage. Based on multiple linear regression analysis, MQI was significantly positively associated with the disposition index (β: 0.059, SE: 0.002, p = 0.006) after adjustment for menopause, body fat percentage, and the presence of hepatic steatosis according to the hepatorenal index (HRI). Similar findings emerged when including liver enzyme levels in place of hepatic steatosis. Muscle quality was positively associated with β-cell function corrected for insulin resistance among patients with obesity and sarcopenic obesity, irrespective of the presence of fatty liver disease.

The Association between Non-Alcoholic Fatty Liver Disease and Dynapenia in Men Diagnosed with Type 2 Diabetes Mellitus

Background: Dynapenia and non-alcoholic fatty liver disease (NAFLD) are common, especially in the middle and advanced-age diabetic male population. We aimed to examine the clinical features, NAFLD severity, and parameters associated with the presence of dynapenia in type 2 diabetes mellitus (T2DM) cases. Material and Methods: One hundred thirty-five male patients diagnosed with T2DM between 45 and 65 years of age were included. Patients were staged by ultrasonography according to NAFLD status. Results: There were significant differences in muscle strength, upper arm circumference, calf circumference, and up-and-go test scores between the mild-moderate-severe and non-NAFLD groups (p < 0.001 for all). The frequency of dynapenia was lower, and arm and calf circumferences were higher in patients without NAFLD. The muscle strength, upper arm circumference, calf circumference, and up-and-go test scores were significantly lower in the dynapenic group compared to the non-dynapenic group (p < 0.005 for all). The prevalence of dynapenia increased along with the increase in NAFLD stages (p < 0.001). Conclusions: We detected a significant association between NAFLD and dynapenia in middle-aged men with T2DM. As muscle strength decreases, the amount of fat in the liver increases, and as the fat in the liver increases, muscle strength decreases.

Is dynapenic abdominal obesity a risk factor for cardiovascular mortality? A competing risk analysis

BACKGROUND

Dynapenic abdominal obesity has been shown as a risk factor for all-cause mortality in older adults. However, there is no evidence on the association between this condition and cardiovascular mortality.

OBJECTIVE

We aimed to investigate whether dynapenic abdominal obesity is associated with cardiovascular mortality in individuals aged 50 and older.

METHODS

A longitudinal study with an 8-year follow-up was conducted involving 7,030 participants of the English Longitudinal Study of Ageing study. Abdominal obesity and dynapenia were respectively defined based on waist circumference (> 102 cm for men and > 88 cm for women) and grip strength (< 26 kg for men and < 16 kg for women). The sample was divided into four groups: non-dynapenic/non-abdominal obesity (ND/NAO), non-dynapenic/abdominal obesity (ND/AO), dynapenic/non-abdominal obesity (D/NAO) and dynapenic/abdominal obesity (D/AO). The outcome was cardiovascular mortality. The Fine-Grey regression model was used to estimate the risk of cardiovascular mortality as a function of abdominal obesity and dynapenia status in the presence of competing events controlled by socio-demographic, behavioural and clinical variables.

RESULTS

The risk of cardiovascular mortality was significantly higher in individuals with D/AO compared with ND/NAO (SHR 1.85; 95% CI: 1.15-2.97). D/NAO was also associated with cardiovascular mortality (SHR: 1.62; 95% CI: 1.08-2.44).

CONCLUSION

Dynapenic abdominal obesity is associated with cardiovascular mortality, with a larger effect size compared to dynapenia alone in individuals older than 50 years. Thus, prevention strategies and clinical interventions that enable mitigating the harmful effects of these conditions should be adopted to diminish such risk.

Age-Related Dysfunction in Proteostasis and Cellular Quality Control in the Development of Sarcopenia

Sarcopenia is a debilitating skeletal muscle disease that accelerates in the last decades of life and is characterized by marked deficits in muscle strength, mass, quality, and metabolic health. The multifactorial causes of sarcopenia have proven difficult to treat and involve a complex interplay between environmental factors and intrinsic age-associated changes. It is generally accepted that sarcopenia results in a progressive loss of skeletal muscle function that exceeds the loss of mass, indicating that while loss of muscle mass is important, loss of muscle quality is the primary defect with advanced age. Furthermore, preclinical models have suggested that aged skeletal muscle exhibits defects in cellular quality control such as the degradation of damaged mitochondria. Recent evidence suggests that a dysregulation of proteostasis, an important regulator of cellular quality control, is a significant contributor to the aging-associated declines in muscle quality, function, and mass. Although skeletal muscle mammalian target of rapamycin complex 1 (mTORC1) plays a critical role in cellular control, including skeletal muscle hypertrophy, paradoxically, sustained activation of mTORC1 recapitulates several characteristics of sarcopenia. Pharmaceutical inhibition of mTORC1 as well as caloric restriction significantly improves muscle quality in aged animals, however, the mechanisms controlling cellular proteostasis are not fully known. This information is important for developing effective therapeutic strategies that mitigate or prevent sarcopenia and associated disability. This review identifies recent and historical understanding of the molecular mechanisms of proteostasis driving age-associated muscle loss and suggests potential therapeutic interventions to slow or prevent sarcopenia.

Combined Effect of Dynapenia and Abdominal Obesity on the Prevalence of Peripheral Artery Disease in Older Adults Over 75 Years Old in China

The objective is to examine the separate and joint effects of dynapenia and abdominal obesity on the prevalence of peripheral artery disease (PAD) in older adults of different ages (60-74 and over 75 years old). This study comprised 1293 community-dwelling Chinese participants recruited from Shanghai, China, who were aged at least 60 years (753 women; mean age: 72.0 ± 5.9 years). Dynapenia was defined as low-grip strength (<28.0 kg for males and <18.0 kg for females) but normal skeletal muscle index (≥7.0 kg/m² for males and ≥5.7 kg/m² for females). Abdominal obesity was determined according to waist circumference (≥90 cm for males and ≥85 cm for females), and PAD was diagnosed by an ankle-brachial index  ≤ 0.9. Binary logistic regression models were performed to determine associations between dynapenia, abdominal obesity, and the combination of dynapenia and abdominal obesity and PAD. According to dynapenia and abdominal obesity status stratified by age (60-74 or over 75), the patients were divided into 4 groups: normal, dynapenia alone, abdominal obesity alone, and co-occurring groups. A logistic regression showed that the co-occurring groups (odds ratio = 4.63, 95% confidence interval = 1.41-15.21) had a higher prevalence of PAD than the normal group after adjusting for the covariates in older adults over 75 years of age. The combination of dynapenia and abdominal obesity increase the prevalence of PAD in older adults over 75 years. The present findings have important implications for the early identification of older adults with PAD and appropriate interventions should be implemented.

A single-set functional training program increases muscle power, improves functional fitness, and reduces pro-inflammatory cytokines in postmenopausal women: A randomized clinical trial

Introduction: Aging can be associated with reduced muscle power, functional decline, and increased plasma concentrations of proinflammatory cytokines. Functional training (FT) can improve muscle power, functional fitness and reduce plasma cytokines. However, the functional training optimal volume required to produce these adaptations must be clarified. Our study analyzed the effects of multiple-set functional training (MSFT) and single-set functional training (SSFT) on postmenopausal women's muscle power, functional fitness, and inflammatory profile. Methods: Forty-three women were randomly allocated into three groups: multiple-set functional training (n = 16, age 64.13 ± 5.17), single-set functional training (n = 14, age 63.79 ± 4.88), and control group (CG, n = 13, age 64.62 ± 5.44). The bench press and squat exercises evaluated upper and lower limb muscle power. The following tests assessed functional fitness: putting on and taking off a T-shirt, gallon-jug shelf-transfer, standing up and walking around the house, five times sit-to-stand, and 400-m walk. Plasma cytokine (TNF-α, IL-6, and IL 10) concentrations were measured by flow cytometry. Results: Single-set functional training and multiple-set functional training increased upper and lower limbs muscle power and improved functional fitness, except for the putting on and taking off a T-shirt test. Multiple-set functional training reduced TNF-α and IL-6, while single-set functional training reduced only TNF-α. IL-10 was unaffected by exercise. Discussion: Single-set functional training and multiple-set functional training, therefore, promoted similar muscle power and functional fitness improvements over 24 weeks. Multiple-set functional training was more effective than single-set functional training, reducing both TNF and IL-6, while single-set functional training only decreased TNF-α.

Low muscle strength and low phase angle predicts greater risk to mortality than severity scales (APACHE, SOFA, and CURB-65) in adults hospitalized for SARS-CoV-2 pneumonia

Introduction

The acute physiology and chronic health evaluation (APACHE), sepsis-related organ failure assessment (SOFA), score for pneumonia severity (CURB-65) scales, a low phase angle (PA) and low muscle strength (MS) have demonstrated their prognostic risk for mortality in hospitalized adults. However, no study has compared the prognostic risk between these scales and changes in body composition in a single study in adults with SARS-CoV-2 pneumonia. The great inflammation and complications that this disease presents promotes immobility and altered nutritional status, therefore a low PA and low MS could have a higher prognostic risk for mortality than the scales. The aim of the present study was to evaluate the prognostic risk for mortality of PA, MS, APACHE, SOFA, and CURB-65 in adults hospitalized with SARS-CoV-2 pneumonia.

Methodology

This was a longitudinal study that included n = 104 SARS-CoV-2-positive adults hospitalized at General Hospital Penjamo, Guanajuato, Mexico, the PA was assessed using bioelectrical impedance and MS was measured with manual dynamometry. The following disease severity scales were applied as well: CURB-65, APACHE, and SOFA. Other variables analyzed were: sex, age, CO-RADS index, fat mass index, body mass index (BMI), and appendicular muscle mass index. A descriptive analysis of the study variables and a comparison between the group that did not survive and survived were performed, as well as a Cox regression to assess the predictive risk to mortality.

Results

Mean age was 62.79 ± 15.02 years (31-96). Comparative results showed a mean PA of 5.43 ± 1.53 in the group that survived vs. 4.81 ± 1.72 in the group that died, p = 0.030. The mean MS was 16.61 ± 10.39 kg vs. 9.33 ± 9.82 in the group that died, p = 0.001. The cut-off points for low PA was determined at 3.66° and ≤ 5.0 kg/force for low grip strength. In the Cox multiple regression, a low PA [heart rate (HR) = 2.571 0.726, 95% CI = 1.217-5.430] and a low MS (HR = 4.519, 95% CI = 1.992-10.252) were associated with mortality.

Conclusion

Phase angle and MS were higher risk predictors of mortality than APACHE, SOFA, and CURB-65 in patients hospitalized for COVID-19. It is important to include the assessment of these indicators in patients positive for SARS-CoV-2 and to be able to implement interventions to improve them.

Circulating Inflammatory, Mitochondrial Dysfunction, and Senescence-Related Markers in Older Adults with Physical Frailty and Sarcopenia: A BIOSPHERE Exploratory Study

Multisystem derangements encompassing musculoskeletal, stress, and metabolic response have been described in older adults with physical frailty and sarcopenia (PF&S). Whether PF&S is also associated with markers of cellular senescence has yet to be explored. To address this research question, we quantified the serum levels of selected inflammatory, mitochondrial, and senescence-associated secretory phenotype (SASP)-related factors in 22 older adults with PF&S (mean age 75.5 ± 4.7 years; 81.8% women) and 27 nonPF&S controls (mean age 75.0 ± 4.4 years; 62.9% women) and evaluated their association with PF&S. Markers of inflammation (interleukin (IL)1-β, IL6, and tumor necrosis factor α (TNF-α)), matrix remodeling (Serpin E1, intercellular adhesion molecule 1 (ICAM-1), and tissue inhibitor of metalloproteinases 1 (TIMP-1)), mitochondrial dysfunction (growth/differentiation factor 15 (GDF15) and fibroblast growth factor 21 (FGF21)), Activin A, and glial fibrillary acidic protein (GFAP) were assayed. Serum levels of TNF-α and those of the SASP-related factors ICAM-1 and TIMP-1 were found to be higher, while IL1-β and IL6 were lower in PF&S participants compared with controls. Partial least squares discriminant analysis allowed discrimination of PF&S from nonPF&S participants with 74.0 ± 3.4% accuracy. Markers that significantly contributed to the classification were ICAM-1, TIMP-1, TNF-α, GFAP, and IL6. Future studies are warranted to establish whether inflammatory and SASP-related pathways are causally linked to the development and progression of PF&S, and may represent new targets for interventions.

Comparison of three nutritional screening tools for detecting sarcopenia in patients with maintenance hemodialysis

Background

Malnutrition, dynapenia, and sarcopenia are prevalent conditions among patients with maintenance hemodialysis (MHD). They are related to numerous adverse health outcomes. The aim of this study was to compare the effect of three nutritional screening tools on predicting the risk of dynapenia and sarcopenia in patients with MHD.

Methods

From July 2020 to April 2021, a total of 849 patients with MHD were enrolled at seven different healthcare facilities in Shanghai, China in this multi-center cross-sectional study. Geriatric nutritional risk index (GNRI), malnutrition inflammation score (MIS), and creatinine (Cr) index were used for nutritional assessment. The cutoff values of muscle mass and strength to define dynapenia, pre-sarcopenia, and sarcopenia were based on the consensus by the Asia Working Group of Sarcopenia in 2019.

Results

Among 849, almost 60% were malnourished with the majority suffering from dynapenia (27.7%), followed by sarcopenia (22.7%), and pre-sarcopenia (6.2%).The area under the receiver-operating characteristic curve for GNRI was 0.722 [95% confidence interval (CI) = 0.684-0.760] and 0.723 (95% CI = 0.663-0.783) in predicting sarcopenia and pre-sarcopenia. The GNRI [odds ratio (OR) =6.28, 95% CI: 4.05-9.73], MIS (OR =1.91, 95% CI: 1.31-2.78), and the Cr index (OR =2.73, 95% CI: 1.71-4.34) were all significantly associated with the risk of sarcopenia. More importantly, the sarcopenia predictability of the GNRI appears greater than the MIS and Cr index, while MIS was similar to the Cr index. Similarly, the superiority of GNRI prediction was also found in pre-sarcopenia, but not in dynapenia.

Conclusion

All the three nutritional screening tools were significantly associated with an increased risk of sarcopenia. The sarcopenia predictability of the GNRI was greater than the MIS and Cr index.

Association of Low Handgrip Strength with Chemotherapy Toxicity in Digestive Cancer Patients: A Comprehensive Observational Cohort Study (FIGHTDIGOTOX)

In the FIGHTDIGO study, digestive cancer patients with dynapenia experienced more chemotherapy-induced neurotoxicities. FIGHTDIGOTOX aimed to evaluate the relationship between pre-therapeutic handgrip strength (HGS) and chemotherapy-induced dose-limiting toxicity (DLT) or all-grade toxicity in digestive cancer patients. HGS measurement was performed with a Jamar dynamometer. Dynapenia was defined according to EWGSOP2 criteria (<27 kg (men); <16 kg (women)). DLT was defined as any toxicity leading to dose reduction, treatment delay, or permanent discontinuation. We also performed an exploratory analysis in patients below the included population’s median HGS. A total of 244 patients were included. According to EWGSOP2 criteria, 23 patients had pre-therapeutic dynapenia (9.4%). With our exploratory median-based threshold (34 kg for men; 22 kg for women), 107 patients were dynapenic (43.8%). For each threshold, dynapenia was not an independent predictive factor of overall DLT and neurotoxicity. Dynapenic patients according to EWGSOP2 definition experienced more hand-foot syndrome (p = 0.007). Low HGS according to our exploratory threshold was associated with more all-grade asthenia (p = 0.014), anemia (p = 0.006), and asthenia with DLT (p = 0.029). Pre-therapeutic dynapenia was not a predictive factor for overall DLT and neurotoxicity in digestive cancer patients but could be a predictive factor of chemotherapy-induced anemia and asthenia. There is a need to better define the threshold of dynapenia in cancer patients.

Aging-related changes in knee flexor muscle strength and cross-sectional area

Weakening muscle strength around the knee tends to render it vulnerable to aging-related damage. This study aimed to examine the association between knee flexor muscle strength and its cross-sectional area (CSA). We also evaluated aging-related changes in flexor muscle strength and CSA. We retrospectively analyzed 252 patients with acute-onset knee pain (<1 month) between September 2006 and August 2009 in accordance with the Strengthening the Reporting of Observational studies in Epidemiology statement. The CSA of each knee flexor muscle (biceps femoris, sartorius, gracilis, semitendinosus (ST), and semimembranosus (SM)) was measured on magnetic resonance imaging axial images at the suprapatellar level. We evaluated flexor muscle strength (peak torque in N.m) using a Cybex dynamometer at 60°/second and 180°/second and its correlation with CSA. In total, 252 patients (mean age, 34.5 years; range, 11 to 66 years; 184 men and 68 women) were included in this study. No significant intergroup differences in demographic data such as sex or body mass index were found. Mean CSA was 605.4 mm2 for the SM, 444.7 mm2 for the biceps femoris, 282 mm2 for the sartorius, 55.4 mm2 for the ST, and 34.1 mm2 for the gracilis. Mean peak torques were 67.4 N.m and 52.7 N.m at 60°/second and 180°/second, respectively. CSA was positively correlated with flexion strengths of 60°/second (R = 0.363, P < .001) and 180°/second (R = 0.354, P < .001). Muscle strength was associated with CSA in all muscles but the gracilis (R = 0.056, P = .375). Flexion strength decreased significantly with aging from the thirties. Total CSA decreased with aging (r = -0.247, P < .001). The CSA of the biceps femoris, sartorius, SM, and ST decreased significantly, whereas that of the gracilis tended to decrease non-significantly with aging. Flexor muscle strength was associated with total muscle CSA on magnetic resonance imaging and the CSA of every muscle except the gracilis. Flexion strength decreased significantly with aging after the twenties, while total CSA decreased significantly with aging. The CSA of all flexor muscles decreased significantly with aging, whereas that of the gracilis decreased only slightly.

Association of Micronutrients and Handgrip Strength in Korean Older Population: A Cross-Sectional Study

Sarcopenia is characterized by the loss of skeletal muscle mass, strength, and physical performance. Dynapenia and kratopenia are described as the loss of muscle strength and power. Nutritional intake status is one of the factors affecting the prevention of an age-related muscle decline such as sarcopenia, dynapenia, or kratopenia in older populations. This study aimed to investigate the association between the intake of micronutrients and handgrip strength in 1254 individuals (546 men and 708 women) of the Korean older population from the most recent dataset. They were analyzed and divided into two groups: a LHS group with low handgrip strength (<28 kg for men and <18 kg for women) and a normal group with normal handgrip strength. Logistic regression analysis was performed to estimate the odds ratios (ORs) and 95% confidence intervals (Cis) of the associations between micronutrient intakes and low handgrip strength in Korean older population by gender. Among micronutrients, insufficient potassium intake showed a significant association with low handgrip strength for men (OR: 3.159, 95% CI: 1.164−8.578) and women (OR: 2.793, 95% CI: 1.380−5.654) aged ≥65 years, respectively (p = 0.005 for men, p = 0.024 for women), as a result of adjusting for all confounding factors that could affect low handgrip strength. In conclusion, potassium intake among micronutrients in Korean older populations with low handgrip strength might need continuous monitoring for the intervention or prevention of dynapenia or sarcopenia.

Gait Characteristics of Dynapenia, Sarcopenia, and Presarcopenia in Community-Dwelling Japanese Older Women: A Cross-Sectional Study

Age-related decline in skeletal muscle mass and function are risk factors for reduced walking ability. This study aimed to understand the characteristic gait parameters of presarcopenia (low muscle mass only), dynapenia (low muscle function only), and sarcopenia (low muscle mass and function), which have differing skeletal muscle characteristics. Skeletal muscle mass, grip strength, and gait parameters (walking speed, cadence, step length, step width, gait angle, foot angle, stance time, swing time, and double stance time) were evaluated in 307 older Japanese women. Low muscle function was determined by grip strength and normal walking speed. Participants were assessed and divided into the normal (60.9%, n = 187), presarcopenia (25.7%, n = 79), dynapenia (5.2%, n = 16), and sarcopenia (8.1%, n = 25) groups. When compared to the normal group, the sarcopenia group had significantly slower walking speed and shorter step length (p < 0.05); the dynapenia group had significantly slower walking speed, smaller cadence, shorter step length, wider step width, and longer stance time (p < 0.05); and the presarcopenia group showed no differences. Skeletal muscle function may therefore be more strongly related to reduced walking function in older adults than body composition factors. The decrease in walking function was most pronounced in older women with dynapenia.

Physical activity and the 'pediatric inactivity triad' in children living with chronic kidney disease: a narrative review

The ‘paediatric inactivity triad’ (PIT) framework consists of three complex inter-related conditions that influence physical inactivity and related health risks. In those living with chronic kidney disease (CKD), a multi-factorial milieu of components likely confound the PIT elements, resulting in a cycle of decreased physical functioning and reduced physical activity. In this review, we explore and summarize previous research on each of the three principal PIT components (exercise deficit disorder, dynapenia, and physical illiteracy) in the pediatric CKD population. We found those living with CKD are significantly physically inactive compared to their peers. Physical inactivity occurs early in the disease process and progressively gets worse as disease burden increases. Although physical activity appears to increase post-transplantation, it remains lower compared to healthy controls. There is limited evidence on interventions to increase physical activity behaviour in this population, and those that have attempted have had negligible effects. Studies reported profound reductions in muscle strength, physical performance, and cardiorespiratory fitness. A small number of exercise-based interventions have shown favourable improvements in physical function and cardiorespiratory fitness, although small sample sizes and methodological issues preclude the generalization of findings. Physical activity must be adapted and individualized to the needs and goals of the children, particularly those with acute and chronic medical needs as is the case in CKD, and further work is needed to define optimal interventions across the life course in this population if we aim to prevent physical activity declining further.

The clinical implications and importance of anemia in older women

OBJECTIVES

The objective of this study was to investigate associations between anemia with geriatric syndromes and comprehensive geriatric assessment (CGA) parameters in older women.

METHODS

886 older outpatient women were included. Anemia was defined as a hemoglobin concentration below 12 g/dL. patients were divided into two groups as anemic and non-anemic. The relationships between anemia and CGA parameters/geriatric syndromes were determined.

RESULTS

The mean age of the participants was 76.00 ± 8.91. The prevalence of patients with anemia was 15.35%. There was a significant difference between anemic and non-anemic groups in terms of age, Charlson Comorbidity Index, body mass index, the number of drugs used, and the presence of chronic renal failure (p < 0.05). After adjustment for these covariates, anemia was associated with Timed Up and Go test (OR: 1.10, 95% CI: 1.02-1.18), muscle strength (OR: 0.99, 95% CI: 0.83-0.99), dynapenia (OR: 1.92, 95% CI: 1.06-3.47), Mini Nutritional Assessment scores (OR: 0.88, 95% CI: 0.83-0.94), poor nutritional status (OR: 1.97, 95% CI: 1.10-3.48), Fried scores (OR: 1.42, 95% CI: 1.24-1.68), frailty (OR: 2.58, 95% CI: 1.42-4.69), falls (OR: 1.78, 95% CI: 1.10-2.92) and polypharmacy (OR: 2.31, 95% CI: 1.38-3.86).

CONCLUSION

In the present study anemia was associated with frailty, polypharmacy, poor nutritional status, falls, and decreased muscle strength. Therefore, anemia may be a sign of poor health status in older women. When anemia is detected in an older woman, CGA should be strongly considered if not routinely performed.

The Effectiveness of a Group Kickboxing Training Program on Sarcopenia and Osteoporosis Parameters in Community-Dwelling Adults Aged 50-85 Years

Background

Sarcopenia and osteoporosis are important health issues faced by older people. These are often associated with each other and share common risk factors and pathologic mechanisms. In the recently revised consensus of the European Working Group on Sarcopenia in Older People, low muscle strength has been defined as the first characteristic of sarcopenia rather than a loss in muscle mass, and walking speed has been stated as an indicator of the severity of sarcopenia. It is believed that these markers of muscle function can be potentially reversed via exercise-based interventions. The purpose of this study was to evaluate the effects of kickboxing exercise training on the parameters of sarcopenia and osteoporosis in community-dwelling adults.

Methods

In total, one hundred eligible subjects were randomized into an intervention group (n = 50) with 76% women and control group (n = 50) with 86% women. Both the intervention and control groups were provided with classroom lectures and personal consultations pertaining to sarcopenia and osteoporosis, whereas a 12-week kickboxing exercise training was arranged only for the intervention group. All anthropometric, physical performance, body composition, and bone mineral density measurements along with participant completed questionnaires were conducted before and after the training period.

Results

After 12 weeks, 41 participants in the intervention group and 34 participants in the control group completed the final assessments. There was no difference between the intervention and control groups in terms of basic demographic data. The BMI (+1.14%) of the control group increased significantly during the study period. The waist circumference (−6.54%), waist-to-height ratio (−6.57%), waist–to–hip ratio (−4.36%), total body fat (−1.09%), and visceral fat area (−4.6%) decreased significantly in the intervention group. Handgrip strength (+5.46%) and gait speed (+5.71%) improved significantly in the intervention group. The lean body mass increased by 0.35% in the intervention group and by 0.9% in the control group. The femoral neck bone mineral density (−1.45%) and T score (−3.72%) of the control group decreased significantly. The intervention group had more improvement in the status of sarcopenia (OR 1.91) and osteoporosis over the control group. Finally, the intervention group had less deterioration in the status of sarcopenia (OR 0.2) and osteoporosis (OR 0.86) compared with the control group.

Conclusion

Our study demonstrated that a 12-week kickboxing exercise training program is effective for improving sarcopenic parameters of muscle strength and function, but not muscle mass in adults, aged 50–85 years. Furthermore, markers of osteoporosis also showed improvement. These findings suggest that a 12-week kickboxing program is effective for muscle and bone health among community-dwelling older individuals.

Relationship between Sarcopenia and Cardiovascular Disease Risk among Taiwanese Older Adults

OBJECTIVE

Increasing evidence supports sarcopenia as an important parameter for predicting cardiometabolic risks. The objective of this study was to investigate the relationship between muscle mass, muscle strength, and physical performance, and cardiovascular risk among older community-dwelling adults.

DESIGN

The associations between dynapenia, sarcopenia, and Framingham risk score (FRS) were estimated by multivariate regression models.

SETTING

Muscle mass is estimated by skeletal muscle mass index using a bioelectrical impedance analysis. Muscle strength is measured by handgrip strength using an analog isometric dynamometer. Physical performance is measured by gait speed using a 6-meter walking distance. Dynapenia was defined as low muscle strength and/or slow gait speed presents with normal muscle mass. The diagnosis of presarcopenia and sarcopenia was based on criteria proposed by the Asian Working Group for Sarcopenia in 2014. The FRS was used for evaluating 10-year coronary heart disease risk.

PARTICIPANTS

Adults aged 65 years and older who attended health examinations from 2015 to 2017 were recruited.

RESULTS

There were totally 709 subjects enrolled in this study. Dynapenic men (n=47) had 17.70±5.08% FRS and sarcopenic women (n=74) had 7.74±6.06% FRS. Participants with presarcopenia had the lowest FRS (men: 15.41±5.35%; women: 5.25±3.70%). Men with dynapenia had higher FRS than the presarcopenia group with odds ratio (OR) of 2.52 (95% Confidence Interval [CI]: 1.03-6.14). Women with sarcopenia had significantly higher FRS than the presarcopenia group with OR of 2.81 (95%CI: 1.09-7.27).

CONCLUSION

Older dynapenic men and older sarcopenic women had higher risks of 10-year coronary heart disease. Presarcopenic older adults had the lowest coronary heart disease risk in both genders.

Higher Serum Leptin Levels are Associated with a Reduced Risk of Sarcopenia but a Higher Risk of Dynapenia Among Older Adults

Background

Leptin plays an important role in regulating the energy homeostasis of fat and muscle. Paradoxical findings existed between serum leptin levels and muscle health conditions. Here, we aimed to investigate the relationship between serum leptin levels and the risk of sarcopenia or dynapenia among older adults.

Methods

Adults aged 65 and older living in the community were recruited at annual health checkups. Body composition, gait speed, and handgrip strength were examined. The cutoff values of muscle mass and strength to define sarcopenia and dynapenia were based on the consensus by the Asia Working Group of Sarcopenia in 2019. Serum leptin level was measured by an immunoassay.

Results

Four hundred sixty participants (55.65% females) were enrolled. There were 16.08% and 23.91% with sarcopenia and dynapenia, respectively. Higher serum leptin levels were positively associated with muscle and fat mass but negatively associated with handgrip strength and gait speed for both sexes. In the logistic regression models adjusted for various confounders, a higher serum leptin level was associated with an increased risk of dynapenia with dose-response effects among both male and female participants (odds ratio [OR]=3.74, 95% confidence interval [CI]= 0.99–14.17; OR= 3.32, 95% CI=1.03–10.74, respectively), and a positive trend existed in both genders (p for trend=0.040 and 0.042, respectively). In contrast, a higher leptin level was associated with a reduced risk of sarcopenia with dose-response trends for both sexes (OR= 0.06, 95% CI=0.01–0.48; OR= 0.26, 95% CI=0.06–1.17, respectively) in models of multivariate logistic regression analyses, and a negative trend existed in both genders (p for trend = 0.002 and 0.023, respectively).

Conclusion

A positive trend existed between the serum leptin level and the dynapenia risk, whereas it revealed a negative trend in the serum leptin level and sarcopenia risk in both male and female elderly individuals. The biological mechanisms underlying its negative association with muscle strength but its positive association with muscle mass warrants further investigation.

Dynapenia Rather Than Sarcopenia Is Associated with Metabolic Syndrome in Patients with Chronic Liver Diseases

We aimed to examine the association between sarcopenia-related factors and metabolic syndrome (Met-S) in patients with chronic liver diseases (CLDs, n = 582, average age = 59.5 years, 290 males, 168 liver cirrhosis cases). Met-S was determined based on the Japanese criteria. Sarcopenia was determined based on grip strength (GS) and skeletal muscle index (SMI) by bioelectrical impedance analysis. Our cohort was divided into the four groups: (A) sarcopenia (n = 44), (B) dynapenia (n = 45), (C) presarcopenia (n = 112), and (D) the control (n = 381). Impacts of GS and SMI on Met-S were investigated. In males, waist circumference (WC) ≥ 85 cm was observed in 199 patients (68.6%), while in females, WC ≥ 90 cm was observed in 94 patients (32.2%). Met-S was identified in 109 patients (18.7%). The proportion of Met-S in the group A, B, C and D were 18.2%, 48.9%, 8.0%, and 18.4% (A vs. B, p = 0.0033; B vs. C, p < 0.0001; C vs. D, p = 0.0081; A vs. C, p = 0.0867; A vs. D, p = 1.000, B vs. D, p < 0.0001; overall p value < 0.0001). Multivariate analysis revealed that age, gender, and group B (dynapenia) were significant factors linked to the presence of Met-S. In conclusion, dynapenia rather than sarcopenia is associated with Met-S in CLD patients.

Potential Utility of Electrical Impedance Myography in Evaluating Age-Related Skeletal Muscle Function Deficits

Skeletal muscle function deficits associated with advancing age are due to several physiological and morphological changes including loss of muscle size and quality (conceptualized as a reduction in the intrinsic force-generating capacity of a muscle when adjusted for muscle size). Several factors can contribute to loss of muscle quality, including denervation, excitation-contraction uncoupling, increased fibrosis, and myosteatosis (excessive levels of inter- and intramuscular adipose tissue and intramyocellular lipids). These factors also adversely affect metabolic function. There is a major unmet need for tools to rapidly and easily assess muscle mass and quality in clinical settings with minimal patient and provider burden. Herein, we discuss the potential for electrical impedance myography (EIM) as a tool to evaluate muscle mass and quality in older adults. EIM applies weak, non-detectible (e.g., 400 μA), mutifrequency (e.g., 1 kHz–1 MHz) electrical currents to a muscle (or muscle group) through two excitation electrodes, and resulting voltages are measured via two sense electrodes. Measurements are fast (~5 s/muscle), simple to perform, and unaffected by factors such as hydration that may affect other simple measures of muscle status. After nearly 2 decades of study, EIM has been shown to reflect muscle health status, including the presence of atrophy, fibrosis, and fatty infiltration, in a variety of conditions (e.g., developmental growth and maturation, conditioning/deconditioning, and obesity) and neuromuscular diseases states [e.g., amyotrophic lateral sclerosis (ALS) and muscular dystrophies]. In this article, we describe prior work and current evidence of EIM’s potential utility as a measure of muscle health in aging and geriatric medicine.

Linear and non-linear associations between physical activity, body composition and multimorbidity over 10 years among community-dwelling older adults

BACKGROUND

This study aims to describe the relationships between physical activity (PA), body composition and multimorbidity over 10 years.

METHODS

Participants (N=373; 49% women; average age 61.3±6.7 years) were followed for 10 years. Multimorbidity was defined by self-report as the presence of two or more of 12 listed chronic conditions. PA (steps-per-day) at baseline was assessed by pedometer, handgrip strength (HGS) by dynamometer and appendicular lean mass (ALM) and total body fat mass by dual x-ray absorptiometry . Relative HGS and ALM were calculated by dividing each body mass index (BMI). Regression cubic splines were used to assess evidence for a non-linear relationship.

RESULTS

After 10 years, 45% participants had multimorbidity. There was a non-linear relationship between PA and multimorbidity - PA was associated with lower multimorbidity risk among individuals who engaged in <10,000 steps-per-day (RR=0.91, 95% CI: 0.85, 0.97, per 1000 steps-per-day), but not among those who participated in ≥10,000 steps-per-day (RR=1.04, 95% CI: 0.93, 1.09, per 1000 steps-per-day). Higher BMI (RR=1.05, 95% CI: 1.02, 1.08, per kg/m 2) and fat mass (RR=1.03, 95% CI: 1.01, 1.04, per kg), and lower relative HGS (RR=0.85, 95% CI: 0.77, 0.94, per 0.1 psi/kg/m 2) and ALM (RR=0.93, 95% CI: 0.88, 0.98, per 0.1 kg/kg/m 2) were linearly associated with a higher risk of multimorbidity. Absolute HGS and ALM were not significantly associated with multimorbidity.

DISCUSSION

These findings highlight the potential clinical importance of maintaining adequate levels of PA and of reducing adiposity and maintaining muscle function for minimising the risk of multimorbidity in older adults.

Female cancer survivors are more likely to be at high risk of malnutrition and meet the threshold for clinical importance for a number of quality of life subscales

BACKGROUND

The present study aimed to explore malnutrition risk, handgrip strength and quality of life (QOL) in cancer survivors.

METHODS

In total, 232 individuals completed a demographic questionnaire, Patient-Generated Subjective Global Assessment Short Form and the European Organization for Research and Treatment of Cancer QOL Questionnaire (EORTC QLQ-C30). Handgrip strength was determined using a spring-loaded handgrip dynamometer and anthropometric measurements were taken by an oncology nurse. Frequencies and distribution data, analysis of variance and chi-squared tests were then conducted.

RESULTS

The majority of the cohort were female (n = 141; 60.8%) had breast cancer (n = 62; 26.7%) and the mean ± SD body mass index (BMI) was 26.6 ± 6.2 kg m^-2 . Less than a one-third reported seeing a dietitian (n = 68; 29.3%). Over one-third reported recent weight loss (n = 88; 37.3%). Some 40.9% (n = 95) were at moderate to high risk of malnutrition, with women more likely than men to be classified as high risk (p < 0.05). Mean ± SD handgrip strength was 25 ± 15 kg and this differed significantly by gender (p = 0.00), cancer type (p = 0.01) and BMI classification (p = 0.01). One-fifth of individuals were classified as having dynapenia (n = 48; 21.1%). Median (interquartile range) QOL score was 66.7 (33.3). The proportion of individuals meeting the threshold for clinical importance for QOL subscales ranged from 12.5% (constipation) to 42.7% (physical functioning). Females were more likely than males to meet the threshold for physical functioning (p = 0.00), fatigue (p = 0.02) and pain (p = 0.01).

CONCLUSIONS

Females are more likely than males to be at high risk of malnutrition and meet the threshold for clinical significance for several QOL subscales.

Impact of adiposity on muscle function and clinical events among elders with dynapenia, presarcopenia and sarcopenia: a community-based cross-sectional study

INTRODUCTION

Low muscle function determined unfavorable clinical outcome than low muscle mass; nevertheless, comparison of detrimental parameters among dynapenia, presarcopenia and sarcopenia was sparse. We hypothesized that adiposity is implicated in low muscle function related adverse events.

METHODS

We recruited community elders to measure handgrip strength and walking speed. Using bioelectronics impedance analyzer to examine body compositions. The faller is indicated of having a fall event in the past one year. Associations of different obesity parameters, metabolic syndrome (MetS) and fall among the groups were analyzed.

RESULTS

Among 765 participants, the dynapenia group had higher metabolic profiles, body fat percentage (BFP), waist circumference, and fat to muscle ratio (FMR) than the other groups, whereas the presarcopenia subjects had the lowest obesity parameters. The fallers tended to have poorer muscle function than non-fallers (p<0.001). The dynapenia individuals had the highest risk for MetS (odds ratio [OR]= 5.79; 95% confidence interval [CI]= 2.45-13.73), and the highest fall risk (OR= 3.11; 95% CI=1.41-6.87). Among obesity parameters, FMR had better diagnostic performance to estimate low muscle function, followed by BFP.

CONCLUSION

Dynapenia individual had higher risk of obese-related adverse events. Increased adiposity irrespective of muscle mass is relevant to reduced muscle function among elders.

Aging and Recovery After Resistance-Exercise-Induced Muscle Damage: Current Evidence and Implications for Future Research

Aging is anecdotally associated with a prolonged recovery from resistance training, though current literature remains equivocal. This brief review considers the effects of resistance training on indirect markers of muscle damage and recovery (i.e., muscle soreness, blood markers, and muscle strength) in older males. With no date restrictions, four databases were searched for articles relating to aging, muscle damage, and recovery. Data from 11 studies were extracted for review. Of these, four reported worse symptoms in older compared with younger populations, while two have observed the opposite, and the remaining studies (n = 6) proposed no differences between age groups. It appears that resistance training can be practiced in older populations without concern for impaired recovery. To improve current knowledge, researchers are urged to utilize more ecologically valid muscle-damaging bouts and investigate the mechanisms which underpin the recovery of muscle soreness and strength after exercise in older populations.

Examining the association between grip strength and testosterone

BACKGROUND

Skeletal muscle is an important site for storing proteins and providing general physical function. Recent research has shown that muscle strength decreases earlier than muscle mass decreases, as shown during the aging process. Our article aimed to compare the association between testosterone levels and grip strength to provide an earlier biomarker to detect muscle weakness.

METHOD

We adopted quartile-based analysis by dividing handgrip power into quartiles, with all participants in the lowest quartile serving as the reference group. Linear regression analysis was conducted between handgrip power and testosterone. Logistic regression models were used to analyze the longitudinal correlation between testosterone levels and the presence of low muscle strength.

RESULTS

Serum testosterone levels had a significant correlation with grip strength in all models (p < .001). In addition, high testosterone levels were negatively associated with low muscle strength in all groups (p < .001). A stronger relationship was observed between testosterone levels and grip strength among non-obese participants than among obese participants.

CONCLUSIONS

In conclusion, our study highlighted that testosterone levels are related to greater grip strength.

Relationships of the stand-up time to falls and fractures in patients with rheumatoid arthritis: Results from the CHIKARA study

AIM

Patients with rheumatoid arthritis (RA) have a higher risk of falls and fractures due to muscle weakness and painful joints of the lower extremities. Evaluation of muscle functions is important to predict falls and fractures. The aim was to investigate the relationships of muscle functions with falls and fractures in RA patients.

METHODS

Stand-up muscle power, speed, and stabilizing time were evaluated by a muscle function analyzer in 90 RA patients in the CHIKARA study (UMIN000023744). The relationships of the muscle functions with falls, fractures, body composition, Disease Activity Score of 28 joints - erythrocyte sedimentation rate (DAS28-ESR), modified Health Assessment Questionnaire (mHAQ) scores, Steinbrocker class, stage, sarcopenia, and frailty were investigated in a cross-sectional study.

RESULTS

Each parameter of muscle function was related to age, falls, frailty, and the leg muscle score. However, only stabilizing time was related with fractures (r = .217, P = .04). When stabilizing time was ≥ 1.13 and ≥1.36 seconds, the odds ratios for falls and fractures were increased 6.2-fold compared to < 1.13 seconds (95% CI: 1.2-20.1, P = .002) and 11.4-fold compared to <1.36 seconds (95% CI: 1.7-92.5, P = .071), respectively. Sarcopenia and skeletal muscle mass were not significantly related to each muscle function. There was a negative correlation between DAS28-ESR and power. Steinbrocker class and mHAQ had negative correlations with power and speed.

CONCLUSIONS

Sarcopenia and skeletal muscle mass were not adequate indicators of muscle functions in RA patients. Analyzing muscle functions is helpful to predict falls and fractures. Patients with extended stabilizing times should recognize the increased risk of falls and fractures.

Dynapenia and physical performance in community-dwelling elderly people in Japan

Aging of society has increased the incidence of physical disability. The goal of this study was to examine the physical ability of elderly people classified as having sarcopenia, presarcopenia, or dynapenia (a low muscle function without low muscle mass) in a community in Japan. The subjects were volunteers aged >60 years who were participants in a health checkup in Yakumo, Hokkaido and were in good general health. Demographic data were collected and physical performance tests were performed to measure grip strength, walking speed, back muscle strength, maximum stride length, and 3-m timed-up-and-go (3m TUG) time. A measurement of skeletal muscle mass was used as a basis for calculating the appendicular skeletal muscle index (aSMI). The rates of sarcopenia, presarcopenia, and dynapenia were 10%, 22%, and 8% in males (n=101, age 69.7±5.4 years), and 19%, 23%, and 13% in females (n=112, 68.5±5.9 years). Body mass index in subjects with dynapenia was significantly higher compared to that in subjects with sarcopenia and presarcopenia (p<0.01). Back muscle strength, maximum stride length and 3m TUG were similar in dynapenia and sarcopenia, but differed significantly with those in presarcopenia in both males and females without the influence of age (p<0.05). Further studies are needed to evaluate the benefits of dynapenia intervention programs and to explore the underlying pathophysiology of dynapenia.

Identification of Sarcopenia Components That Discriminate Slow Walking Speed: A Pooled Data Analysis

BACKGROUND

The Sarcopenia Definitions and Outcomes Consortium (SDOC) sought to identify cut points for muscle strength and body composition measures derived from dual-energy x-ray absorptiometry (DXA) that discriminate older adults with slow walking speed. This article presents the core analyses used to guide the SDOC position statements.

DESIGN

Cross-sectional data analyses of pooled data.

SETTING

University-based research assessment centers.

PARTICIPANTS

Community-dwelling men (n = 13,652) and women: (n = 5,115) with information on lean mass by DXA, grip strength (GR), and walking speed.

MEASUREMENTS

Thirty-five candidate sarcopenia variables were entered into sex-stratified classification and regression tree (CART) models to agnostically choose variables and cut points that discriminate slow walkers (<0.80 m/s). Models with alternative walking speed outcomes were also evaluated (<0.60 and <1.0 m/s and walking speed treated continuously).

RESULTS

CART models identified GR/body mass index (GRBMI) and GR/total body fat (GRTBF) as the primary discriminating variables for slowness in men and women, respectively. Men with GRBMI of 1.05 kg/kg/m2 or less were approximately four times more likely to be slow walkers than those with GRBMI of greater than 1.05 kg/kg/m2 . Women with GRTBF of less than 0.65 kg/kg were twice as likely to be slow walkers than women with GRTBF of 0.65 kg/kg or greater. Models with alternative walking speed outcomes selected only functions of GR as primary discriminators of slowness in both men and women. DXA-derived lean mass measures did not consistently discriminate slow walkers.

CONCLUSION

GR with and without adjustments for body size and composition consistently discriminated older adults with slowness. CART models did not select DXA-based lean mass as a primary discriminator of slowness. These results were presented to an SDOC Consensus Panel, who used them and other information to develop the SDOC Position Statements. J Am Geriatr Soc 68:1419-1428, 2020.

Age and sex-related decline of muscle strength across the adult lifespan: a scoping review of aggregated data

Muscle strength is sex-related and declines with advancing age; yet, a comprehensive comparative evaluation of age-related strength loss in human females and males has not been undertaken. To do so, segmented piecewise regression analysis was performed on aggregated data from studies published from 1990 to 2018 and are available in CINAHL, EMBASE, MEDLINE, and PsycINFO databases. The search identified 5613 articles that were reviewed for physical assessment results stratified by sex and age. Maximal isometric and isokinetic 60°·s^-1 knee extension (KE) and knee flexion (KF) contractions from 57 studies and 15 283 subjects (N = 7918 females) had sufficient data reported on females and males for meaningful statistical evaluation to be undertaken. The analysis revealed that isometric KE and KF strength undergo similar rapid declines in both sexes late in the sixth decade of life. Yet, there is an abrupt age-related decline in KE 60°·s^-1 peak torque earlier in females (aged 41.8 years) than males (aged 66.7 years). In the assessment of KF peak torque, an age-related acceleration in strength loss was only identified in males (aged 49.3 years). The results suggest that age-related isometric strength loss is similar between sexes while the characteristics of KE and KF peak torque decline are sex-related, which likely explains the differential rate of age-related functional decline. Novelty Inclusion of muscle strength and torque of KE and KF data from >15 000 subjects. Isometric KE and KF strength loss are similar between sexes. Isokinetic 60°·s^-1 KE torque decline accelerates 25 years earlier in females and female age-related KF peak torque decline does not accelerate with age.

Central and Peripheral Neuromuscular Adaptations to Ageing

Ageing is accompanied by a severe muscle function decline presumably caused by structural and functional adaptations at the central and peripheral level. Although researchers have reported an extensive analysis of the alterations involving muscle intrinsic properties, only a limited number of studies have recognised the importance of the central nervous system, and its reorganisation, on neuromuscular decline. Neural changes, such as degeneration of the human cortex and function of spinal circuitry, as well as the remodelling of the neuromuscular junction and motor units, appear to play a fundamental role in muscle quality decay and culminate with considerable impairments in voluntary activation and motor performance. Modern diagnostic techniques have provided indisputable evidence of a structural and morphological rearrangement of the central nervous system during ageing. Nevertheless, there is no clear insight on how such structural reorganisation contributes to the age-related functional decline and whether it is a result of a neural malfunction or serves as a compensatory mechanism to preserve motor control and performance in the elderly population. Combining leading-edge techniques such as high-density surface electromyography (EMG) and improved diagnostic procedures such as functional magnetic resonance imaging (fMRI) or high-resolution electroencephalography (EEG) could be essential to address the unresolved controversies and achieve an extensive understanding of the relationship between neural adaptations and muscle decline.

Corticospinal Control of Human Locomotion as a New Determinant of Age-Related Sarcopenia: An Exploratory Study

Sarcopenia is a muscle disease listed within the ICD-10 classification. Several operational definitions have been created for sarcopenia screening; however, an international consensus is lacking. The Centers for Disease Control and Prevention have recently recognized that sarcopenia detection requires improved diagnosis and screening measures. Mounting evidence hints towards changes in the corticospinal communication system where corticomuscular coherence (CMC) reflects an effective mechanism of corticospinal interaction. CMC can be assessed during locomotion by means of simultaneously measuring Electroencephalography (EEG) and Electromyography (EMG). The aim of this study was to perform sarcopenia screening in community-dwelling older adults and explore the possibility of using CMC assessed during gait to discriminate between sarcopenic and non-sarcopenic older adults. Receiver Operating Characteristic (ROC) curves showed high sensitivity, precision and accuracy of CMC assessed from EEG Cz sensor and EMG sensors located over Musculus Vastus Medialis [Cz-VM; AUC (95.0%CI): 0.98 (0.92-1.04), sensitivity: 1.00, 1-specificity: 0.89, p < 0.001] and with Musculus Biceps Femoris [Cz-BF; AUC (95.0%CI): 0.86 (0.68-1.03), sensitivity: 1.00, 1-specificity: 0.70, p < 0.001]. These muscles showed significant differences with large magnitude of effect between sarcopenic and non-sarcopenic older adults [Hedge's g (95.0%CI): 2.2 (1.3-3.1), p = 0.005 and Hedge's g (95.0%CI): 1.5 (0.7-2.2), p = 0.010; respectively]. The novelty of this exploratory investigation is the hint toward a novel possible determinant of age-related sarcopenia, derived from corticospinal control of locomotion and shown by the observed large differences in CMC when sarcopenic and non-sarcopenic older adults are compared. This, in turn, might represent in future a potential treatment target to counteract sarcopenia as well as a parameter to monitor the progression of the disease and/or the potential recovery following other treatment interventions.