AGE-RELATED CHANGES IN THE STRUCTURE AND FUNCTION OF SKELETAL MUSCLES

Age-dependent properties of the rabbit calf musculature - Relationship between mechanic and microstructure

In order to meet the requirements of body weight and height and the associated changing tasks and movement patterns during the growth of living bodies, significant changes in the skeletal musculature occur during this phase. In this study, the age-dependent (between 21 and 100 days) mechanical and microstructural tissue behaviour of the calf musculature, consisting of soleus muscles (SOL), gastrocnemius muscles (GAS) and plantaris muscles (PLA), was examined. To this end, cubic muscle tissue samples were examined using axial and semi-confined compression experiments. In addition, the essential muscle tissue components (muscle fibres, extracellular matrix, remaining components) were analysed. In a final step, these results were linked to morphological properties of the animals and muscles (animal mass, muscle mass, tibia length). Interestingly, the mechanical properties of the individual muscle types hardly differ from each other during growth, while both the morphological and microstructural properties change significantly. Thus, a clear increase of all morphological parameters (animal mass by 850%, muscle mass by 1000% (SOL), 1183% (GAS) and 1050% (PLA), tibia length by 235%) can be seen. In comparison, the microstructural parameters show a less consistent trend. The proportion of muscle fibres in the tissue cross-section increases by about 138% in the SOL, whereas the fibre proportion in both the GAS and PLA increases by only 109%. Consequently, the ECM proportion in the tissue cross-section decreases by 48%, 58% and 52% for SOL, GAS and PLA. Overall, the data obtained her e provides a deeper understanding of muscle growth and, in particular, of different muscle types that have different functions inside the calf. On the other hand, these data represent a good and comprehensive basis for later model developments.

Title: Shear Wave Elastography (SWE) of Hamstring Muscles and Outcome Measures in Rheumatology (OMERACT) Knee Osteoarthritis Ultrasound Scores in Patients With Knee Osteoarthritis With MRI Association: A Cross Sectional Observational Study

BACKGROUND

The Outcome Measures in Rheumatology (OMERACT) and MRI Osteoarthritis Knee Score (MOAKS) scores are semi-quantitative scores used in the evaluation knee osteoarthritis (KOA) by ultrasonography (US) and MRI. Assessment of hamstring muscle function, which is very important for the prognosis and rehabilitation of KOA patients, can be attempted by shear wave elastography (SWE).

AIM

To study the SWE of hamstring muscles and OMERACT US scores in patients with KOA and compare them with MOAKS scores.

METHOD

This prospective, observational study was done on 80 patients with KOA who underwent MRI, US, and SWE examinations with calculation of MOAKS and OMERACT scores, as well as VTI and VTIQ assessment of hamstrings. Comparison of the findings of these was done, and appropriate statistical tests were applied.

RESULT

Statistically significant associations were found between OMERACT and MOAKS using Spearman Rho correlation for osteophytes (0.816 with p value 0.001), meniscal extrusion (0.514 with p value 0.001), cartilage abnormalities (0.442 with p value 0.001), joint effusion (0.397 with p value 0.001) and synovitis (0.34 with p value 0.002). The stiffness of hamstring muscles on SWE were also significantly correlated with MOAKS and OMERACT scores with p value of < 0.05 and 0.014, respectively. Color coding and stiffness on VTIQ of hamstring muscles were also significantly associated with BML size (p value 0.001), cartilage abnormalities (p value 0.001), osteophytes (p value 0.001), synovitis (p value 0.05), and meniscal extrusion (p value 0.001) found on MRI.

CONCLUSION

US of knee with SWE of hamstrings can be used not only as a primary screening modality for KOA but also for proper rehabilitation and management of these patients.

Comparison of predictive models for knee pain and analysis of individual and physical activity variables using interpretable machine learning

BACKGROUND

Knee pain is associated with not only individual factors such as age and obesity but also physical activity factors such as occupational activities and exercise, which has a significant impact on the lives of adults and the elderly.

OBJECTIVES

The purpose of this study was to construct a model for predicting knee pain using individual and physical activity variables and to determine the relationship between knee pain and individual and physical activity variables.

DESIGN

Observational study.

METHODS

A total of 19 variables related to individual and physical activity were used to create a knee pain prediction model. Model composition variables were selected using recursive feature elimination with cross validation. The performance of the model was evaluated using test data, and the relationship between knee pain and predictor variables was analyzed using SHapley Additive exPlanations (SHAP).

RESULTS

The CatBoost model showed the highest performance. And, activity limitation was identified as the most influential predictor, followed by weekly physical activity, body image, weight change, occupational type, age, BMI, and housing type.

CONCLUSION

Knee pain prediction models built with individual and physical activity variables can exhibit relatively high predictive performance, and interpretable machine learning models can provide valuable insight into the complex relationships between individual and physical activity variables and knee pain.

Effects of dynamic stabilization and fusion on postoperative paraspinal muscle degeneration and lumbar function recovery

OBJECTIVE

To investigate the relationship between segmental motion and paraspinal muscle degeneration at the surgical level in patients with single-level lumbar degenerative disease (LDD) who have undergone either fusion or dynamic stabilization surgery.

METHODS

Patients treated with posterolateral intertransverse fusion (PITF group), Isobar TTL dynamic internal fixation (TTL group), or Isobar EVO dynamic internal fixation (EVO group) for single-level lumbar degenerative disease (LDD) between March 2012 and September 2020 were included in the study. Cases were selected with complete records and follow-up times ranging from 2 to 5 years, taking into account the effects of postoperative muscle edema and age-related muscle degeneration. The study compared operative time, intraoperative blood loss, preoperative and postoperative Oswestry Disability Index (ODI) scores, Lumbar Stiffness Disability Index (LSDI) scores, range of motion (ROM) at the surgical segment, cross-sectional area (CSA) of the paraspinal muscles, and functional cross-sectional area (FCSA) of the paraspinal muscles before and after surgery across all groups.

RESULTS

A total of 73 patients were included in this study: 23 in the PITF group, 26 in the TTL group, and 24 in the EVO group. There were no statistically significant differences among the three groups in terms of age, gender, follow-up duration, body mass index (BMI), preoperative lumbar VAS score, preoperative ODI score, and preoperative LSDI score (P > 0.05). Postoperative ODI scores were significantly higher in the PITF group compared to the TTL and EVO groups, with ODI scores demonstrating a moderate negative correlation with postoperative range of motion (ROM) of the surgical segment (Pearson's r = -0.333, P < 0.004). A strong negative monotonic relationship was observed between ROM of the surgical segment and the rate of change in functional cross-sectional area (FCSA) of the paraspinal muscles across all groups, as evidenced by Spearman's correlation coefficients (PITF: r = -0.766, P < 0.001; TTL: r = -0.818, P < 0.001; EVO: r = -0.865, P < 0.001) (Fig. 7). Multiple linear regression models confirmed that age, BMI, and gender had no significant effect on the rate of FCSA change. For the PITF, TTL, and EVO groups, the regression coefficients for ROM's association with FCSA change were β = -0.653 (P < 0.005), β = -0.956 (P < 0.001), and β = -0.908 (P < 0.001), respectively. Similarly, postoperative LSDI scores were significantly elevated in the PITF group compared to the TTL and EVO groups, with LSDI scores exhibiting a strong negative correlation with postoperative ROM (r = -0.802, P < 0.001).

CONCLUSION

Compared to traditional decompression combined with rigid fusion surgery, decompression coupled with dynamic stabilization techniques can more effectively alleviate postoperative lumbar stiffness and functional impairment in patients. Moderately enhancing the range of motion at the surgical level facilitates the remodeling of paraspinal muscle tissue following surgery.

Exploration of Pathogenesis and Cutting-Edge Treatment Strategies of Sarcopenia: A Narrative Review

Sarcopenia a progressive and multifactorial musculoskeletal syndrome characterized by loss of muscle mass and function, poses a significant global health challenge, particularly in aging populations. Epidemiological studies reveal that sarcopenia affects approximately 5-10% of the general population, with prevalence rates escalating dramatically after age 60 to reach 10-27% in older adults. This age-associated increase contributes significantly to healthcare burdens by elevating risks of disability, frailty, and mortality. Despite its profound impact, current clinical approaches to sarcopenia remain limited. While resistance exercise and protein supplementation form the cornerstone of management, their efficacy is often constrained by poor long-term adherence and variable individual responses, highlighting the urgent need for more comprehensive and personalized treatment strategies. The pathogenesis of sarcopenia is complex and influenced by various factors, including aging, inflammation, nutritional deficits, physical inactivity, and mitochondrial dysfunction. However, the precise molecular mechanisms underlying this condition are still not fully understood. Recent research has made significant strides in elucidating the intricate mechanisms contributing to sarcopenia, revealing novel insights into its molecular and cellular underpinnings. Notably, emerging evidence points to the pivotal role of mitochondrial dysfunction, altered myokine profiles, and neuromuscular junction degeneration in sarcopenia progression. Additionally, breakthroughs in stem cell therapy, exosome-based treatments, and precision nutrition offer promising avenues for clinical intervention. This review aims to synthesize the latest advancements in sarcopenia research, focusing on the novel contributions to its pathogenesis and treatment strategies. We explore emerging trends such as the role of cellular senescence, epigenetic regulation, and targeted therapeutic interventions that could reshape future approaches to managing sarcopenia. By highlighting recent breakthroughs and cutting-edge research, we hope to advance the understanding of sarcopenia and foster the translation of these findings into effective clinical therapies.

Quantitative analysis of gait dysfunction in sarcopenia patients: Based on spatiotemporal parameters and kinematic performance

BACKGROUND

Sarcopenia is the disease characterized by muscle loss, and leading to functional decline and increased mortality, especially affects the elderly. Gait abnormalities are common perform the dysfunction but are understudied quantitatively.

METHOD

Sixty-two participants (20 sarcopenia, 42 healthy) were recruited for gait analysis. The clinically characterized data including anthropometric data, muscle mass, handgrip strength were measured. The spatiotemporal and the kinematic parameters during gait were also captured through the motion capture.

RESULTS

Sarcopenia patients exhibited significantly reduced stride length (1.12 ± 0.13 m vs. 1.20 ± 0.10 m, p = 0.006) and gait speed (0.96 ± 0.14 m/s vs. 1.10 ± 0.12 m/s, p < 0.001), alongside increased stride time (1.17 ± 0.08 s vs. 1.10 ± 0.08 s, p = 0.005) compared to healthy controls. Joint kinematics revealed significant differences in hip flexion-extension range (40.66° ± 5.44° vs. 41.69° ± 6.12°, p < 0.05) and knee adduction-abduction range (10.51° ± 3.53° vs. 13.85° ± 5.28°, p < 0.05) during gait stance phase.

CONCLUSION

The reduced stride length and speed, along with wider step width, highlight the functional decline impacted by sarcopenia. The gait patterns were also influenced with patients adopting conservative strategies for stability. Joint angle differences suggest limitations in sagittal and coronal plane movements, affecting balance and joint biomechanics. This quantitative study demonstrates the functional impact of sarcopenia on gait, emphasizing the need for comprehensive assessment and tailored interventions to improve mobility and quality of life in elderly populations.

Explaining trunk strength variation and improvement following resistance training in people with chronic low back pain: clinical and performance-based outcomes analysis

A multitude of variables contribute to the variation of trunk strength in individuals with chronic low back pain (CLBP). This study investigated a range of variables to determine which variables contribute most to variation in trunk isometric strength and gains in strength following resistance training in people with CLBP. Outcome measures were recorded from 20 participants with CLBP both at baseline and following resistance training. Regression analyses were applied with the average trunk maximum voluntary isometric torque as the dependent variable. Variance in baseline trunk flexion strength (R2 = .66) was explained by demographic covariates and a measure of trunk muscle co-activation. The baseline trunk extension strength variance (R2 = .65) was explained by demographic covariates and lumbar erector spinae (LES) activity during a maximum trunk extension contraction. Demographic variables, trunk muscle co-activation, baseline trunk flexion strength, level of physical function, and pain intensity over the past week influenced the change in trunk flexion strength after training (R2 = .93). Demographic variables and LES muscle activity explained the variance in trunk extension strength at follow-up (R2 = .64). This study supports the major influence of sex, physical function and baseline strength and muscle activity, on the variation in maximum trunk strength in participants with CLBP at baseline and gains in trunk muscle strength following progressive resistance training.

Intermuscular adipose tissue affected muscle density more than intramuscular adipose tissue content with opportunistic screening at abdominal CT

This study aimed to determine whether intermuscular adipose tissue (IMAT) or intramuscular adipose tissue content (IMAC) has a greater effect on skeletal muscle density (SMD) and to explore the underlying mechanisms. We recruited 292 inpatients without musculoskeletal system disease, all of whom underwent abdominal CT. Muscle parameters, including skeletal muscle area (SMA), skeletal muscle index (SMI), SMD, IMAC, and IMAT, as well as fat parameters-subcutaneous fat area (SFA) and subcutaneous fat density (SFD) in the abdominal wall-were measured by two musculoskeletal radiologists using ImageJ software at the third lumbar vertebra (L3) level. One-way ANOVA with LSD (chi-square test for group comparisons where p > 0.05) or Dunnett's T3 test (p < 0.05) was employed to compare muscle parameters between genders and across age groups. The relationship between SMD and muscle measurements was analyzed using Spearman's correlation coefficient. Multiple regression analysis identified and compared factors influencing SMD. SMD was highly correlated with IMAT and IMAC (p < 0.05), moderately correlated with gender, age, and SFA (p < 0.05). Multiple linear regression analysis indicated that IMAC, IMAT, and age significantly affected SMD (p < 0.05), with the order of influence being IMAT (β = -0.616), IMAC (β = -0.429), and age (β = -0.098). SFA and gender did not significantly affect SMD (p > 0.05). The findings revealed that age, IMAT, and IMAC influence SMD, with IMAT exerting the most significant impact.

Preservation of Temporal Organisation of Tennis Service Following Ageing in Recreational Players

Background: Ageing leads to functional changes in body systems. Purpose: This study sought to examine the age-based differences in temporal patterning, temporal variability and temporal regularity of tennis service in older adults. Research design: cross-sectional study. Study sample: Participants of this study were volunteers from young (n = 10) and older (n = 11) adults who were self-defined as non-competitive, participating in tennis at a recreational (sub-elite) level for 2-3 days per week regularly. Data collection: They were asked to perform 20 trials of the same serves (flat, slice or top-spin) on a regular size court. The timing (duration) of the serve action was recorded and analysed, using a high-speed digital camera. Participants performed the tennis serves during their routine training sessions on a tennis court. They undertook a structured general (10min) and a specific warm-up routine (10min) before performing services. There was a 30-second rest period between trials. Results: Findings showed that there were no statistically significant differences between the two groups in temporal patterning, whereas the younger group performed the serves with higher variability and regularity/consistency than the older adults in some phases of the action. Conclusion: Older adults who participate recreationally in sports are able to preserve some functional organisation of perceptual-motor capacities, such as timing, due to long-term practice effects. The findings illustrate how sport participation may help maintain functional movement organisation following ageing to mitigate age-related declines in perception and action in late adulthood.

Assessment of muscle fatigability using isometric repetitive handgrip strength in frail older adults. A cross-sectional study

BACKGROUND

Fatigue has a significant impact on physical performance and quality of life in older adults, but is subjectively assessed in the Fried phenotype, so early deterioration may be overlooked. This study explores whether repetitive handgrip strength (HGS) provides an objective method of differentiating levels of frailty by comparing fatigue and recovery ratios with subjective measures and their correlations with frailty indicators.

METHODS

Participants (n = 217) were included based on mobility and cognitive function (MMSE > 17), with exclusions for neuromuscular disease or hand injury. The protocol consisted of two 10-maximal grip assessments one hour apart, calculating fatigue ratios 1 and 2 (maximum/mean force) at each session and recovery ratios between sessions. Logistic regression analysed associations between Fried's criteria components (Unintentional Weight Loss, Exhaustion Single Question, Multidimensional Fatigue Inventory (MFI), Short Physical Performance Battery (SPPB), Physical Activity Scale for the Elderly (PASE), standard Maximum HGS, Fatigue Ratio, and Recovery Ratio).

RESULTS

Among the participants (58 non-frail, 68 pre-frail, 91 frail; ages 74.7, 79.4, 83.8 years), significant differences were found for Fatigue Ratio 1 of 1.12 (non-frail), 1.23 (pre-frail), 1.40 (frail), Fatigue Ratio 2 of 1.12, 1.21, 1.45, and Recovery Ratio of 1.03, 1.01, 0.90, respectively. Fatigue Ratios 1, 2 and Recovery correlated more strongly with frailty status (r = 0.67, 0.69, -0.68) than MFI (r = 0.50), standard maximum HGS (r = -0.51) or a single fatigue question (r = 0.21). In logistic regression for predicting fatigue (MFI), Fatigue Ratio (OR = 1.51, p < 0.001) and Recovery Ratio (OR = 0.83, p = 0.022) were stronger predictors than single-question fatigue (OR = 1.15, p = 0.047) and maximum HGS. For predicting frailty, physical performance (SPPB) was the strongest predictor (OR = 0.72, p < 0.001), followed by Fatigue Ratio 1 (OR = 1.28, p < 0.001), with a higher Recovery Ratio reducing frailty risk (OR = 0.86, p = 0.050).

CONCLUSION

The repetitive HGS protocol is equivalent to the SPPB in assessing frailty and outperforms standard HGS and subjective fatigue measures. This objective method supports the identification of frailty by measuring strength, fatigue resistance and recovery capacity.

The impact of undernutrition on the association between hypomagnesemia and dynapenia in older women

OBJECTIVES

To determine the association between hypomagnesemia and dynapenia in older women with different nutritional status.

METHODS

This cross-sectional study included older women who attended one outpatient geriatric clinic. Undernutrition was defined according to the Mini Nutritional Assessment score (MNA) (< 23,5), and handgrip strength of < 16 kg on dynamometer was defined as dynapenia. The association between hypomagnesemia (serum magnesium < 1.7 mg/dL) and dynapenia was determined by logistic regression analysis.

RESULTS

Among the 933 older women (mean age 81 ± 8), the prevalences of undernutrition and hypomagnesemia were 61% and 15%, respectively. The risk of hypomagnesemia increased with each step of decline in nutritional status, and undernutrition was associated with hypomagnesemia (OR 1.64, 95% CI 1.11-2.43, p = 0.013) In the entire cohort, hypomagnesemia was associated with dynapenia (OR 2.01, 95% CI 1.35-3.00, p = 0.001). In well-nourished patients, hypomagnesemia was not associated with dynapenia, even when unadjusted. However, in the undernourished group, hypomagnesemia was associated with dynapenia after adjusting for age, diabetes mellitus, hypertension, coronary heart disease, Barthel and Lawton scores, polypharmacy, glomerular filtration rate, serum albumin, hemoglobin, and MNA score (OR 2.95, 95% CI 1.04-8.32, p = 0.040). The coexistence of hypomagnesemia and undernutrition (versus neither of them) was significantly associated with dynapenia (OR 4.44, 95% CI 2.67-7.41, p < 0.001).

CONCLUSION

The prevalence of hypomagnesemia increases with worsening nutritional status. Hypomagnesemia is associated with dynapenia in older women who are undernourished, even after adjusting for nutritional status, but not in those who are well nourished. The coexistence of undernutrition and hypomagnesemia increase the risk of dynapenia substantially.

Reactive oxygen species in the pathogenesis of sarcopenia

One of the most critical factors impacting healthspan in the elderly is the loss of muscle mass and function, clinically referred to as sarcopenia. Muscle atrophy and weakness lead to loss of mobility, increased risk of injury, metabolic changes and loss of independence. Thus, defining the underlying mechanisms of sarcopenia is imperative to enable the development of effective interventions to preserve muscle function and quality in the elderly and improve healthspan. Over the past few decades, understanding the roles of mitochondrial dysfunction and oxidative stress has been a major focus of studies seeking to reveal critical molecular pathways impacted during aging. In this review, we will highlight how oxidative stress might contribute to sarcopenia by discussing the impact of oxidative stress on the loss of innervation and alteration in the neuromuscular junction (NMJ), on muscle mitochondrial function and atrophy pathways, and finally on muscle contractile function.

Impact of Whole-Body Vibration Therapy in Elderly Populations: A Scoping Review

The aging population faces neuromuscular stability, balance, and cardiovascular health challenges. This comes with a financial burden, morbidity, and reduced quality of life. Whole-body vibration (WBV) is a potential noninvasive therapy to address these challenges. This review aimed to determine and document the quality and extent of WBV therapy benefits in the elderly, as reported in the literature. OVID, EMBASE, and Web of Science were searched for peer-reviewed articles written in English between January 2008 and November 2024. Included were articles involving WBV effects on cardiovascular hemodynamics, neuromuscular stability, and sarcopenia in persons aged 50 and older. The initial search yielded 467 articles, and 37 were included for final review. The reported cardiovascular benefits of WBV included increased skin blood flow and improved markers of endothelial cell function. Mixed results exist for arterial stiffness metrics, and there was no significant impact of WBV on blood pressure. The most promising evidence relates to sarcopenia, where significant improvements were reported in muscle strength, performance, and functionality. Elderly persons with osteoarthritis had similar results, in addition to reduced pain and stiffness. Patients with Parkinson's disease were reported to have improvements in tremor, rigidity, and postural stability. In contrast, stroke patients had mixed results in muscle activation but showed improvement in ankle joint proprioception. We conclude that although there is some evidence supporting the benefits of WBV on heart rate, muscle strength, function, and arterial stiffness, contradictory findings are reported. This points to the need for further research and a better definition of the optimal dosage of WBV, including its amplitude and frequency.

Iron Chelation Prevents Age-Related Skeletal Muscle Sarcopenia in Klotho Gene Mutant Mice, a Genetic Model of Aging

BACKGROUND

A decline in skeletal muscle mass and function known as skeletal muscle sarcopenia is an inevitable consequence of aging. Sarcopenia is a major cause of decreased muscle strength, physical frailty and increased muscle fatigability, contributing significantly to an increased risk of physical disability and functional dependence among the elderly. There remains a significant need for a novel therapy that can improve sarcopenia and related problems in aging. Iron accumulation, especially catalytic iron (labile iron) through increased oxidative stress, could be one of the contributing factors to sarcopenia. Our study aimed to examine the effect of an iron chelator on age-related sarcopenia in mice.

METHODS

We investigated the effect of iron chelation (deferiprone, DFP) in sarcopenia, using mice with klotho deficiency (kl/kl), an established mouse model for aging. Four weeks old Klotho -/- male mice were treated with 25 mg/kg body weight of iron chelator deferiprone in drinking water for 8-14 weeks (n = 12/group, treated and untreated). At the end of the study, gastrocnemius, quadriceps and bicep muscles were dissected and used for western blot and immunohistochemistry analysis, histopathology and iron staining. Serum total iron, catalytic iron and cytokine ELISAs were performed with established methods.

RESULTS

Treatment with DFP significantly reduced loss of muscle mass in gastrocnemius and quadriceps muscles (p < 0.0001). Total and catalytic iron content of serum and iron in muscles were significantly (both p < 0.0001) lower in the treated animals. The inhibitory factor of myogenesis, the myostatin protein in gastrocnemius muscles (p = 0.019) and serum (p = 0.003) were downregulated after 8 weeks of therapy accompanied by an increased in muscle contractile protein myosin heavy chain (~2.9 folds, p = 0.0004). Treatment decreased inflammation (serum IL6 and TNFα) (p < 0.0001, p = 0.005), respectively, and elevated insulin-like growth factor levels (p = 0.472). This was associated with reduced DNA damage and reduced 8-hydroxy 2 deoxyguanosine in muscle and HO-1 protein (p < 0.001, p = 079), respectively. Significant weight loss (p < 0.001) and decreased water intake (p = 0.012) were observed in untreated mice compared to treatment group. Kaplan-Meier survival curves show the median life span of treated mice was 108 days as compared to 63 days for untreated mice (p = 0.0002).

CONCLUSIONS

In summary, our research findings indicate that deferiprone reduced age-related sarcopenia in the muscles of Klotho-/- mice. Our finding suggests chelation of excess iron could be an effective therapy to counter sarcopenia. However, additional studies are needed to evaluate and determine the efficacy in humans.

Systematic Review of Sarcopenia Biomarkers in Hip Fracture Patients as a Potential Tool in Clinical Evaluation

Hip fractures are associated with high morbidity and mortality. Sarcopenia is a significant factor contributing to poor prognosis; however, the clinical diagnosis of sarcopenia remains difficult in surgical patients. This systematic review aims to identify the biomarkers of sarcopenia as diagnostic and predictive tools in patients admitted for hip fracture surgery. A systematic search was conducted in the MEDLINE, EMBASE, and Google Scholar databases according to the PRISMA guidelines. Biomarker study quality was assessed using the BIOCROSS score. A total of 7 studies met the inclusion criteria and 515 patients were included, of whom 402 (78%) were female and 113 (22%) were male. The mean age of the participants was 83.1 years (SD: 5.9). Skeletal muscle biopsies were used for biomarker assessment in 14% (1/7) of studies and venous blood samples were used in the remaining 86% (6/7). The highlighted sarcopenia biomarkers included the low expression of insulin-like growth factor (IGF-I) and tumor necrosis factor-α (TNF-α), along with high serum myostatin and low serum vitamin D levels. Overall, the BIOCROSS score was satisfactory, with all studies obtaining at least a score of 13/20. The orthopedic literature is limited; however, the highlighted biomarkers in this review could be used as adjuncts in the diagnosis of sarcopenia in surgical patients.

The impact of track and field training on dynapenia: gender differences in age-related decline of vertical jump performance among older adults

Introduction

Alongside sarcopenia, the age-related loss of muscle strength and power, known as dynapenia, increases the risk of functional disability and mortality in older adults. However, engaging in sporting activities during old age appears to enhance functional capacity. The differences in effects between athletes and sedentary individuals, as well as between genders, have yet to be fully clarified.

Methods

The vertical jump test is recognized as a measure of lower limb performance with almost no learning effect. In the present study, we quantified age-related countermovement jump (CMJ) height loss in 120 subjects over 58 years old among both master athletes and sedentary counterparts, and analysed gender differences.

Results

Both male and female master athletes showed significantly higher jump heights results than their sedentary counterparts (male athletes 28.5 ± 4.3 cm vs. male sedentaries 15.1 ± 5.2 cm; p < 0.01; female athletes 22.7 ± 2.5 cm vs. female sedentaries 8.2 ± 3.3 cm; p < 0.01). Female athletes were found to have higher CMJ performance than even sedentary men (p < 0.01). The rate of decline in jumping ability was the same for male athletes and non-athletes, but female athletes had the shallower rate of decline of all the groups observed (2.78 cm per decade).

Discussion

Sporting activity in the older age allows both men and women to perform at a higher level, with the latter also benefiting from a slower rate of decline, which can have a positive impact on functional ability and quality of life.

Caffeine Responsiveness Before and After Pilates Training in Healthy Older Adults

Objective

The study aimed to assess responsiveness to the effects of acute caffeine intake after 8 weeks of Pilates intervention in healthy older adults.

Methods

Fifteen healthy older adults performed physical performance regarding daily practice, strength, and balance tests after ingestion of acute 5 mg/kg of caffeine or placebo before and after Pilates training.

Results

The caffeine intake reduced, regardless of Pilates training, the time in 10-m walk test (before placebo vs caffeine, 6.48 ± 0.70 vs 6.51 ± 0.82 seconds; after placebo vs caffeine, 5.84 ± 0.70 vs 5.48 ± 0.61 seconds; P = .008; ηp 2 = 0.404) and timed up and go test (before placebo vs caffeine, 26.30 ± 1.82 vs 24.37 ± 2.12 seconds; after placebo vs caffeine, 22.96 ± 2.36 vs 22.49 ± 2.27 seconds; P = .002; ηp 2 = 0.517) compared with the placebo. Participants were not less responsive to caffeine intake in the 10-m walk test (ΔPre vs ΔPost, -0.33 ± 0.66 vs -0.36 ± 0.53 seconds; P = .888), but they were less responsive for the timed up and go test (ΔPre vs ΔPost, -1.92 ± 2.06 vs -0.47 ± 1.15 seconds; P = 0.030) after Pilates intervention. There were no differences for the sit-to-stand test, rising from the floor, dress and undress T-shirt, handgrip strength, and balance variables.

Conclusion

Although the caffeine improved on the 10-m walk test and timed up and go test performance, healthy older adults were less responsive to caffeine after Pilates training only for performance on the timed up and go test.

Associations between gut microbiota and sarcopenia or its defining parameters in older adults: A systematic review

Altered gut microbiota (GM) potentially contribute to development or worsening of sarcopenia through a gut-muscle axis. This systematic review aims to compare GM between persons with sarcopenia or low sarcopenia-defining parameters (muscle mass, strength, and physical performance) to those with preserved muscle status, as well as to clarify possible associations between sarcopenia (-defining parameters) and relative abundance (RA) of GM-taxa or GM-(α- or β) diversity indices, in order to clarify whether there is robust evidence of the existence of a GM signature for sarcopenia. This systematic review was conducted according to the PRISMA-reporting guideline and pre-registered on PROSPERO (CRD42021259597). PubMed, Web of Science, Embase, ClinicalTrials.gov, and Cochrane library were searched until 20 July 2023. Included studies reported on GM and sarcopenia or its defining parameters. Observational studies were included with populations of mean age ≥50 years. Thirty-two studies totalling 10 781 persons (58.56% ♀) were included. Thirteen studies defined sarcopenia as a construct. Nineteen studies reported at least one sarcopenia-defining parameter (muscle mass, strength or physical performance). Studies found different GM-taxa at multiple levels to be significantly associated with sarcopenia (n = 4/6), muscle mass (n = 13/14), strength (n = 7/9), and physical performance (n = 3/3); however, directions of associations were heterogeneous and also conflicting for specific GM-taxa. Regarding β-diversity, studies found GM of persons with sarcopenia, low muscle mass, or low strength to cluster differently compared with persons with preserved muscle status. α-diversity was low in persons with sarcopenia or low muscle mass as compared with those with preserved muscle status, indicating low richness and diversity. In line with this, α-diversity was significantly and positively associated with muscle mass (n = 3/4) and muscle strength (n = 2/3). All reported results were significant (P < 0.05). Persons with sarcopenia and low muscle parameters have less rich and diverse GM and can be separated from persons with preserved muscle mass and function based on GM-composition. Sarcopenia and low muscle parameters are also associated with different GM-taxa at multiple levels, but results were heterogeneous and no causal conclusions could be made due to the cross-sectional design of the studies. This emphasizes the need for uniformly designed cross-sectional and longitudinal trials with appropriate GM confounder control in large samples of persons with sarcopenia and clearly defined core outcome sets in order to further explore changes in GM-taxa and to determine a sarcopenia-specific GM-signature.

Ingestion of β-nicotinamide mononucleotide increased blood NAD levels, maintained walking speed, and improved sleep quality in older adults in a double-blind randomized, placebo-controlled study

The study evaluated how ingestion of nicotinamide mononucleotide (NMN) for 12 weeks by older adults affected blood nicotinamide adenine dinucleotide (NAD +) levels and physical function, particularly walking function. Information concerning sleep, and stress was also collected as secondary endpoints. In this randomized, placebo-controlled, double-blind, parallel-group comparison study, 60 participants were randomly allocated into a placebo group or NMN group. Members of the NMN group consumed 250 mg/day NMN for 12 weeks. Motor function tests, blood NAD metabolite analysis, and questionnaires were conducted at the start of the study and 4 and 12 weeks after intake. This trial was registered at umin.ac.jp/ctr as UMIN000047871 on June 22nd, 2022.At primary outcome, at both 4 weeks and 12 weeks, the NMN and placebo groups had no significant differences in a stepping test. At secondary outcomes, after 12 weeks of NMN intake, the NMN group had a significantly shorter 4-m walking time than the placebo group as well as significantly higher blood levels of NAD + and its metabolites. A significant negative correlation was observed between the change in the 4-m walking time and the change in blood NAD + , N1-methyl-2-pridone-5-carboxamide (2-PY), and N1-methyl-4-pridone-3-carboxamide (4-PY) at 12 weeks. The NMN group had improved sleep quality at 12 weeks relative to the placebo group as evidenced by lower scores for "Daytime dysfunction" and "Global PSQI" on the Pittsburgh Sleep Questionnaire. No adverse effects related to test substance consumption were observed. Together, these results indicate that NMN intake could increase blood NAD + levels, maintain walking speed, and improve sleep quality in older adults. Interventions involving NMN aimed at maintaining walking speed could contribute to extended healthy life expectancy.

Assessing muscle quality as a key predictor to differentiate fallers from non-fallers in older adults

BACKGROUND

Falling is an important public health issue because of its prevalence and severe consequences. Evaluating muscle performance is important when assessing fall risk. The study aimed to identify factors [namely muscle capacity (strength, quality, and power) and spatio-temporal gait attributes] that best discriminate between fallers and non-fallers in older adults. The hypothesis is that muscle quality, defined as the ratio of muscle strength to muscle mass, is the best predictor of fall risk.

METHODS

184 patients were included, 81% (n = 150) were women and the mean age was 73.6 ± 6.83 years. We compared body composition, mean grip strength, spatio-temporal parameters, and muscle capacity of fallers and non-fallers. Muscle quality was calculated as the ratio of maximum strength to fat-free mass. Mean handgrip and power were also controlled by fat-free mass. We performed univariate analysis, logistic regression, and ROC curves.

RESULTS

The falling patients had lower muscle quality, muscle mass-controlled power, and mean weighted handgrip than the non-faller. Results showing that lower muscle quality increases fall risk (effect size = 0.891). Logistic regression confirmed muscle quality as a significant predictor (p < .001, OR = 0.82, CI [0.74; 0.89]). ROC curves demonstrated muscle quality as the most predictive factor of falling (AUC = 0.794).

CONCLUSION

This retrospective study showed that muscle quality is the best predictor of fall risk, above spatial and temporal gait parameters. Our results underscore muscle quality as a clinically meaningful assessment and may be a useful complement to other assessments for fall prevention in the aging population.

Effects of soy protein-rich meals on muscle health of older adults in long-term care: A randomized clinical trial

OBJECTIVE

This study investigated the effects of a soy protein-rich meal intervention on the muscle health of older adults in long-term care facilities.

METHODS

A 12-week single-center randomized controlled trial with a control-group and open-label design was conducted. Eighty-four older adults from a long-term care facility participated in the study. The chefs at the facility cooked three meals using soy protein-rich recipes designed by dieticians. For 12 weeks, the intervention group participants consumed three meals with 30 g of soy protein (10 g/meal) per day, and the control group participants maintained their habitual diets.

RESULTS

The 84 participants (mean age, 84.9 ± 7.0 years; 61.9% female) were randomly assigned to an intervention group (43 participants) and a control group (41 participants). The intervention group exhibited significant increases in several lean mass indicators, namely soft lean mass (mean, 1.43 kg; 95% confidence interval [CI]: 0.20-1.65 kg), skeletal muscle mass (mean, 1.20 kg; 95% CI: 0.43-1.96 kg), appendicular skeletal muscle mass (mean, 0.79 kg; 95% CI: 0.07-1.52 kg), and skeletal muscle index (mean, 0.37 kg/m2; 95% CI: 0.05-0.68 kg/m2) (all P < 0.05). These changes were not observed in the control group (all P > 0.05). Notably, calf circumference decreased significantly in the control group (mean, -0.98 cm; 95% CI: -1.61 to -0.36 cm) but was maintained in the intervention group. The differences in the calf circumference and 6-m walk performance of the two groups were significant (P < 0.05).

CONCLUSIONS

The 12-week soy protein-rich meal intervention improved the muscle mass and 6-m walk performance of older adults in a long-term care facility.

Assessment of body composition by dual-energy X-Ray absorptiometry in renal transplant patients, hemodialysis patients, and a control group of healthy subjects

BACKGROUND

The clinical findings of patients with Chronic Kidney Disease (CKD), which is characterized by malnutrition, sedentary lifestyle, uremia, and catabolism associated with dialysis produce changes in Body Composition (BC), causing increased Fat Mass (FM), decreased in both Lean Mass (LM) and Body Mineral Density (BMD), even despite uremic reversal after a Kidney Transplant (KT); immunosuppressive medications alter BC, increasing the risk of loss of the kidney transplant and cardiovascular diseases.

OBJECTIVE

To demonstrate whether there are differences in BC between a group of patients with KT and a group of patients on Hemodialysis (HD), when comparing them with a control group without the disease.

MATERIALS AND METHODS

In the present observational study, with a comparative design; 125 patients were evaluated (46 with KT, 47 on HD, and 32 from the healthy control group). The BC was evaluated with the full-body Dual-Energy X-Ray Absorptiometry (DEXA) method.

RESULTS

The mean age and standard deviation (X±SD) of the study subjects were: 28.89 ± 5.76, 27.39 ± 5.04, and 29.63 ± 6.34 years for the HD, KT, and control subjects, respectively. The HD patients presented a total FM of 14.98 ± 6.96 kg in comparison with 20.1 ± 6.5 kg for the control group (p = 0.007), and 19.06 ± 7.94 kg for the group with KT (p = 0.02). The total LM was lower in the KT patients in comparison with the control group (p = 0.023). The content and total BMD were lower in both groups of patients with KT and HD.

CONCLUSIONS

Although a comprehensive improvement in BC was expected after kidney transplantation, the results are not close to "normal' values, when compared with those of healthy subjects of the same age.

The obesity paradox in younger adult patients with sepsis: analysis of the MIMIC-IV database

BACKGROUND

The obesity paradox suggests that individuals with obesity may have a survival advantage against specific critical illnesses, including sepsis. However, whether this paradox occurs at younger ages remains unclear. Therefore, we aimed to investigate whether obesity could improve survival in younger adult patients with sepsis.

METHODS

We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with Sequential Organ Failure Assessment score ≥2 and suspected infection at the time of ICU admission were identified as having sepsis, following the Sepsis-3 definition. Individuals were classified into the obesity (BMI ≥30 kg/m²) and non-obesity (BMI <30 kg/m²) groups. Patients aged <50 and ≥50 years were categorized as younger adult patients and older patients, respectively.

RESULTS

Of 73,181 patients in the MIMIC-IV ICU database, 18,120 satisfied the inclusion criteria: 2642 aged <50 years and 15,478 aged ≥50 years. The Kaplan-Meier curve showed that obesity was not associated with an improved mortality rate among younger adult patients with sepsis (log-rank test: P = 0.197), while obesity exhibited a survival benefit in older patients with sepsis (log-rank test: P < 0.001). After propensity score matching, in-hospital mortality did not differ significantly between the obesity and non-obesity groups (13.3% vs. 12.2%; P = 0.457) in the younger adult patients with sepsis. Multivariate logistic regression analysis revealed that BMI was not an independent risk factor for in-hospital mortality in younger adult patients with sepsis (underweight: adjusted odds ratio [aOR] 1.72, P = 0.076; overweight: aOR 0.88, P = 0.437; obesity: aOR 0.93, P = 0.677; and severe obesity: aOR 1.22, P = 0.580, with normal weight as the reference).

CONCLUSION

Contrary to findings regarding older patients with sepsis, our findings suggest that the obesity paradox does not apply to younger adult patients with sepsis.

Autophagy markers LC3 and p62 in aging lumbar motor neurons

Autophagy is a ubiquitous process through which damaged cytoplasmic structures are recycled and degraded within cells. Aging can affect autophagy regulation in different steps leading to the accumulation of damaged organelles and proteins, which can contribute to cell dysfunction and death. Motor neuron (MN) loss and sarcopenia are prominent features of neuromuscular aging. Previous studies on phrenic MNs showed increased levels of the autophagy proteins LC3 and p62 in 24 month compared to 6 month old mice, consistent with the onset of diaphragm muscle sarcopenia. In the present study, we hypothesized that aging leads to increased expression of the autophagy markers LC3 and p62 in single lumbar MNs. Expression of LC3 and p62 in lumbar MNs (spinal levels L1-L6) was assessed using immunofluorescence and confocal imaging of male and female mice at 6, 18 and 24 months of age, reflecting 100 %, 90 % and 75 % survival, respectively. A mixed linear model with animal as a random effect was used to compare relative LC3 and p62 expression in choline acetyl transferase-positive MNs across age groups. Expression of LC3 and p62 decreased in the white matter of the lumbar spinal cord with aging, with ~29 % decrease in LC3 and ~ 7 % decrease in p62 expression at 24 months of age compared to 6 months of age. There was no change in LC3 or p62 expression in the gray matter with age. LC3 expression in MNs relative to white matter increased significantly with age, with 150 % increase at 24 months of age compared to 6 months of age. Similarly, p62 expression in MNs relative to white matter increased significantly with age, with ~14 % increase at 24 months of age compared to 6 months of age. No effect of sex or MN pool was observed in LC3 and p62 expression in MNs. Overall, these data suggest autophagy impairment during elongation (increased LC3) and degradation (increased p62) phases with aging in lumbar MNs.

Music and Caffeine Intake Effects on Gait, and Its Relationship with Psychological Parameters, in Middle-Aged Women

Purpose

This study aimed to explore the combined effects of caffeine intake and listening to music on walking parameters, and its relationship with psychological variables (fatigue and exercise enjoyment) in middle-aged women.

Patients and Methods

Sixteen healthy middle-aged women, aged between 50 and 60 years old, participated in this study. Their walking parameters (distance, number of steps, steps number/minute, cadence and walking speed) were assessed using the 6-minute walking test (6MWT) in four task conditions: in no-music/no-caffeine, no-music/with caffeine, with music/no-caffeine, and with music/with caffeine conditions. Besides, exercise enjoyment and fatigue were evaluated using the Physical Activity Enjoyment Scale (PACES-8) and rating of perceived exertion (RPE) questionnaires, respectively.

Results

As a result, we found that 100 mg of caffeine intake significantly (p < 0.05) improved walking parameters such as distance, cadence and number of steps during both simple (p < 0.05) and dual-task, while listening to preferred music, where optimal results were found (p < 0.01) with a large effect size (η2p >0.14). Listening to music was sufficient to significantly improve the distance (p < 0.001), cadence (p < 0.001), and walking speed (p < 0.05) values. Besides, both caffeine intake and/or listening to music significantly (p < 0.05 with large effect size (η2p >0.14)) decreased the feeling of fatigue and increased exercise enjoyment while walking in healthy middle-aged women.

Conclusion

In conclusion, caffeine intake seems to positively influence gait capacities, and its combined effects with listening to music, mainly preferred ones, would boost these beneficial effects in middle-aged women.

Assessment of conjunctival, episcleral and scleral thickness in healthy individuals using anterior segment optical coherence tomography

PURPOSE

To determine the thickness of the conjunctiva, episclera and sclera in healthy individuals using anterior segment optical coherence tomography (AS-OCT).

METHODS

We prospectively included 107 healthy individuals of different age groups (18-39 years, 40-54 years, 55-69 years and ≥70 years). For each eye, AS-OCT scans of four quadrants (temporal, nasal, superior and inferior) were acquired. The thickness of the conjunctiva, episclera and sclera was measured for each scan. In addition, the axial length of both eyes was measured, and general characteristics, including smoking, allergies and contact lens use, were collected.

RESULTS

The mean conjunctival thickness was significantly different between the nasal and superior quadrants (87 ± 30 μm vs. 77 ± 16 μm; p < 0.001), as well as the superior and inferior quadrants (77 ± 16 μm vs. 86 ± 19 μm; p = 0.001). The mean episcleral thickness was larger in the superior (174 ± 54 μm) and inferior (141 ± 43 μm) quadrants, compared to the nasal (83 ± 38 μm) and temporal quadrants (90 ± 44 μm). The mean scleral thickness of the inferior quadrant was the largest (596 ± 64 μm), followed by the nasal (567 ± 76 μm), temporal (516 ± 67 μm) and superior (467 ± 52 μm) quadrants (all p < 0.001). The averaged scleral thickness increased 0.96 μm per age year (0.41-1.47 μm, p < 0.001).

CONCLUSIONS

This study provides an assessment of the thickness of scleral and adjacent superficial layers in healthy individuals determined on AS-OCT, which could enable future research into the use of AS-OCT in diseases affecting the anterior eye wall.

Meta-analysis on the interrelationship between sarcopenia and mild cognitive impairment, Alzheimer's disease and other forms of dementia

Sarcopenia has been associated with adverse health outcomes, including cognitive dysfunction. However, its specific interrelationship with neurocognitive disorders such as mild cognitive impairment (MCI), Alzheimer's disease (AD) or other types of dementia has not been thoroughly explored. This meta-analysis aims to summarize the existing evidence on this interrelationship. This systematic review was pre-registered on PROSPERO (CRD42022366309) and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Databases, including PubMed, Embase, CINAHL, Scopus, Web of Science, PEDro, SPORTDiscus and the Cochrane Central Register of Controlled Trials, and the data registry ClinicalTrials.gov were searched from inception to 8 June 2023. Observational studies (cross-sectional and cohort) and interventional studies reporting on the association and prevalence of sarcopenia in MCI, AD or other types of dementia in adults ≥50 years were included. For the meta-analysis, pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association of sarcopenia with the neurocognitive disorders using random-effects/fixed-effects models. Subgroup analyses were performed to identify potential sources of heterogeneity. A total of 77 studies consisting of 92 058 subjects were finally included in the qualitative analysis (71 cross-sectional, 4 cohort and 2 interventional studies). Studies were heterogeneous, using different diagnostic criteria to define both sarcopenia and cognitive status. The majority of studies (n = 38) included Asian community-dwelling older adults. Most studies investigated the association of sarcopenia with AD (33/77) and MCI (32/77). For studies focusing on other forms of dementia, two studies included Lewy body dementia and one study included Parkinson's dementia, whereas the remaining studies did not specify dementia aetiology (n = 21). Three cohort studies explored the association between sarcopenia and incident MCI, whereas only one cohort study explored the association between dementia and incident sarcopenia. Two interventional studies investigated whether an exercise programme could prevent the progression of sarcopenia in older adults with dementia or AD. The information for the meta-analysis was extracted from 26 studies. Sarcopenia was significantly associated with MCI (pooled OR = 1.58, 95% CI 1.42-1.76) (n = 14), AD (pooled OR = 2.97, 95% CI 2.15-4.08) (n = 3) and non-AD dementia (pooled OR = 1.68, 95% CI 1.09-2.58) (n = 9). The significance and magnitude of the associations differed in subgroup analyses by study design, population, definition of sarcopenia or used tool to measure cognitive status. This meta-analysis showed that sarcopenia is significantly associated with MCI, AD and other types of dementia. These findings suggest the importance of early screening and prevention of sarcopenia in older people with cognitive dysfunction, although further longitudinal research is needed to clarify the causal relationship.

Immunoengineering Biomaterials for Musculoskeletal Tissue Repair across Lifespan

Musculoskeletal diseases and injuries are among the leading causes of pain and morbidity worldwide. Broad efforts have focused on developing pro-regenerative biomaterials to treat musculoskeletal conditions; however, these approaches have yet to make a significant clinical impact. Recent studies have demonstrated that the immune system is central in orchestrating tissue repair and that targeting pro-regenerative immune responses can improve biomaterial therapeutic outcomes. However, aging is a critical factor negatively affecting musculoskeletal tissue repair and immune function. Hence, understanding how age affects the response to biomaterials is essential for improving musculoskeletal biomaterial therapies. This review focuses on the intersection of the immune system and aging in response to biomaterials for musculoskeletal tissue repair. The article introduces the general impacts of aging on tissue physiology, the immune system, and the response to biomaterials. Then, it explains how the adaptive immune system guides the response to injury and biomaterial implants in cartilage, muscle, and bone and discusses how aging impacts these processes in each tissue type. The review concludes by highlighting future directions for the development and translation of personalized immunomodulatory biomaterials for musculoskeletal tissue repair.

Physical Performance, Body Composition, and Oral Health in Community-Residing Older Adults: A Cross-Sectional Study

Physical activity is essential for healthy aging. This study aimed to identify an association between physical performance, body fat percentage (%BF), and the perception of oral health-related quality of life (OHRQoL) in independent older adults.

METHOD

A group of active older adults was selected from a government-sponsored reunion center in Mexico City. OHRQoL was assessed using the General Oral Health Index (GOHAI), and nutritional status was assessed using the Mini Nutritional Assessment (MNA) tool. A short physical performance battery (SPPB) was applied, and, for body composition, DXA (dual X-ray absorptiometry) was conducted. Data were analyzed using logistic regression models, and marginal probabilities were obtained.

RESULTS

This study involved 366 participants; their mean age was 73.9 (±6.2) years, and 24.9% had type 2 diabetes mellitus (T2DM). OHRQoL information revealed that pain or discomfort in the oral cavity was perceived by 63.9% of the older adults during the previous three months. The SPPB score was low in 159 (43.44%) participants. The logistic regression model revealed that age (OR = 1.13, p < 0.001), T2DM (OR = 2.10, p = 0.009), the risk of malnutrition/malnutrition (OR = 1.76, p = 0.047), high %BF (OR = 1.09, <0.001), and poor OHRQoL (OR = 1.96, p = 0.009) were associated with deteriorated physical performance.

CONCLUSION

OHRQoL self-perception, excess body fat, and nutritional status impacted physical performance. Aging well requires a comprehensive approach.

Social support in maintaining mental health and quality of life among community-dwelling older people with functional limitations in Malaysia: a population-based cross-sectional study

OBJECTIVE

This study aimed to examine the mediation role of perceived social support in the relationship between functional limitations, depressive symptoms and quality of life among older people in Malaysia.

SETTING

The Malaysian National Health Morbidity Survey 2018: Elderly Health was a cross-sectional health community survey among adults aged 50 and above.

PARTICIPANTS

3977 community-dwelling older Malaysians aged 60 and above.

OUTCOME MEASURES

Functional limitations were defined as personal activities of daily living (PADL) and instrumental activities of daily living (IADL), tested in separate paths in all analyses. PADL was measured using the Barthel Index, while IADL was measured using the Lawton and Brody scale. Perceived social support, depressive symptoms and quality of life were measured using the Duke Social Support Index, Geriatric Depression Scale-14 and Control, Autonomy, Self-Realisation and Pleasure-19 tools. We used mediation analysis through structural equation modelling to explore the role of perceived social support.

RESULTS

Perceived social support mediated the relationship between PADL and IADL with depressive symptoms, with the indirect effects at -0.079 and -0.103, respectively (p<0.001). Similarly, perceived social support mediated the relationship between PADL and IADL with quality of life, with the indirect effects at 0.238 and 0.301, respectively (p<0.001). We performed serial multiple mediation analysis and found that perceived social support and depressive symptoms mediated the path between PADL and IADL with quality of life, with the indirect effects at 0.598 and 0.747, respectively (p<0.001). The relationship between functional limitations and all outcomes remained significant in all mediation analyses.

CONCLUSION

The present study provides evidence that perceived social support relieves the influence of functional limitations on depressive symptoms and declining quality of life among older people. Therefore, it is imperative to establish a social support system to improve the overall well-being of older people.

Effects of physical exercise on neuromuscular junction degeneration during ageing: A systematic review

The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.

Predictive Value of a New Muscle Parameter in Patients with Resectable Gastric Cancer: A Pooled Analysis of Three Prospective Trials

BACKGROUND

Sarcopenia is closely associated with gastric cancer (GC) prognosis. However, its exact definition remains controversial.

METHODS

This study included computed tomography images and clinical data of patients from three prospective studies. The skeletal muscle index (SMI) and skeletal muscle radiation attenuation (SMRA) were analyzed, and a new muscle parameter, skeletal muscle gauge (SMG), was obtained by multiplying the two parameters. The values of the three indices for predicting the prognosis of patients with GC were compared.

RESULTS

The study included 717 patients. The findings showed median values of 42 cm2/m2 (range, 36.8-48.2 cm2/m2) for SMI, 45 HU (range, 41-49 HU) for SMRA, and 1842 (range, 1454-2260) for SMG. Postoperatively, 111 patients (15.5%) experienced complications. The 3-year overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) were 74.3%, 68.2%, and 70%, respectively. Univariate logistic analysis showed that postoperative complications were associated with SMI (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.92-0.96), SMRA (OR, 0.87; 95% CI 0.84-0.90), and SMG (OR 0.99; 95% CI 0.98-0.99). After a two-step multivariate analysis, only SMG (OR 0.98, 95% CI 0.97-0.99) was an independent protective factor of postoperative complications. Multivariate analysis showed that SMG also was an independent protective factor of OS, DFS, and RFS. The patients were divided into low-SMG (L-SMG) group and high-SMG (H-SMG) groups. Chemotherapy benefit analysis of the patients with stage II low SMG showed that the OS, DFS, and RFS of the chemotherapy group were significantly better than those of the non-chemotherapy group (p < 0.05).

CONCLUSION

The prospective large sample data showed that the new muscle parameter, SMG, can effectively predict the short-term outcome and long-term prognosis of patients with resectable gastric cancer. As a new muscle parameter index, SMG is worthy of further study.

An optimized approach to study nanoscale sarcomere structure utilizing super-resolution microscopy with nanobodies

The sarcomere is the fundamental contractile unit in skeletal muscle, and the regularity of its structure is critical for function. Emerging data demonstrates that nanoscale changes to the regularity of sarcomere structure can affect the overall function of the protein dense ~2μm sarcomere. Further, sarcomere structure is implicated in many clinical conditions of muscle weakness. However, our understanding of how sarcomere structure changes in disease, especially at the nanoscale, has been limited in part due to the inability to robustly detect and measure at sub-sarcomere resolution. We optimized several methodological steps and developed a robust pipeline to analyze sarcomere structure using structured illumination super-resolution microscopy in conjunction with commercially-available and fluorescently-conjugated Variable Heavy-Chain only fragment secondary antibodies (nanobodies), and achieved a significant increase in resolution of z-disc width (353nm vs. 62nm) compared to confocal microscopy. The combination of these methods provides a unique approach to probe sarcomere protein localization at the nanoscale and may prove advantageous for analysis of other cellular structures.

Blood Profiles of Community-Dwelling People with Sarcopenia: Analysis Based on the China Health and Retirement Longitudinal Study

INTRODUCTION

Routine blood factors can be economical and easily accessible candidates for sarcopenia screening and monitoring. The associations between sarcopenia and routine blood factors remain unclear. This study aimed to examine sarcopenia and blood factor associations based on a nation-wide cohort in China.

METHODS

A total of 1,307 participants and 17 routine blood indices were selected from two waves (year 2011 and year 2015) of the China Health and Retirement Longitudinal Study (CHARLS). The diagnosis of sarcopenia was based on the criteria proposed by the Asian Working Group for Sarcopenia (AWGS 2019). Generalized mixed-effects models were performed for association analyses. A logistic regression (LR) model was conducted to examine the predictive power of identifying significant blood factors for sarcopenia.

RESULTS

A higher sarcopenia risk was cross-sectionally associated with elevated blood concentrations of high-sensitivity C-reactive protein (hsCRP) (OR = 1.030, 95% CI [1.007, 1.053]), glycated hemoglobin (HbA1c) (OR = 1.407, 95% CI [1.126, 1.758]) and blood urea nitrogen (BUN) (OR = 1.044, 95% CI [1.002, 1.089]), and a decreased level of glucose (OR = 0.988, 95% CI [0.979, 0.997]). A higher baseline hsCRP value (OR = 1.034, 95% CI [1.029, 1.039]) and a greater over time change in hsCRP within 4 years (OR = 1.034, 95% CI [1.029, 1.039]) were associated with a higher sarcopenia risk. A higher BUN baseline value was related to a decreased sarcopenia risk over time (OR = 0.981, 95% CI [0.976, 0.986]), while a greater over time changes in BUN (OR = 1.034, 95% CI [1.029, 1.040]) and a smaller over time change in glucose (OR = 0.992, 95% CI [0.984, 0.999]) within 4 years were also related to a higher sarcopenia risk. LR based on significant blood factors (i.e., hsCRP, HbA1c, BUN, and glucose), and sarcopenia status in year 2015 yielded an area under the curve of 0.859 (95% CI: 0.836-0.882).

CONCLUSION

Routine blood factors involved in inflammation, protein metabolism, and glucose metabolism are significantly associated with sarcopenia. In clinical practice, plasma hsCRP, BUN, blood sugar levels, sex, age, marital status, height, and weight might be helpful for sarcopenia evaluation and monitoring.

The relationship between resting metabolic rate and quality of life is moderated by age and body composition in women: a cross-sectional study

BACKGROUND

Health-related quality of life (HRQOL) is related to body composition, which is also related to resting metabolic rate (RMR). RMR can be increased by exercise and diet interventions that are not dependent on changes in body composition, so a link between RMR and HRQOL may provide interventions that directly improve HRQOL in women.

METHODS

One hundred twenty women (median age 63.5 [IQR: 53.0-71.0] years) completed one-time measurement of body composition (multi-frequency bioelectrical impedance), RMR (handheld calorimetry), and HRQOL (RAND-36). Physical (PCS) and mental (MCS) composite scores were calculated for the RAND-36. Pearson correlations were used to identify relationships between RMR, body composition, and HRQOL. Variables at the p < .01 level were entered into multiple regression models.

RESULTS

Median body mass index was 26.1 [IQR: 23.2-30.9] kg/m2 and median lean mass index was 16.1 [IQR: 14.6-17.3] kg/m2. Body composition consisted of fat mass (median 27.2 [IQR: 20.3-34.7] kg) and lean mass (median 42.7 [IQR: 38.2-46.9] kg). Median RMR was 1165.0 [IQR: 1022.5-1380.0] kcal/day. Median HRQOL scores were PCS (84.0 [IQR: 74.0-93.0]) and MCS (85.0 [IQR: 74.3-90.0]). RMR was not directly related to PCS, but was directly and negatively related to MCS (p = .002). RMR was significantly and positively related to body composition (lean mass: p < .001; fat mass: p < .001), body mass index (p = .005), and lean mass index (p < .001); but only fat mass (PCS: p < .001; MCS: p < .001) and body mass index (PCS: p < .001; MCS: p < .001) were related to HRQOL, although the relationship was negative. In addition, age was found to be significantly negatively related to RMR (p < .001) and PCS (p = .003). Regression models confirmed the moderating influence of age and body composition on the relationship between RMR and HRQOL. RMR, age, fat mass, and body mass index explained 24% (p < .001) of variance in PCS; and RMR, fat mass, and body mass index explained 15% (p < .001) of variance in MCS.

CONCLUSION

In women, the relationship between RMR and HRQOL is moderated by age and body composition. Understanding these pathways will allow clinicians and researchers to direct interventions more effectively.

Comparing the Impacts of Testosterone and Exercise on Lean Body Mass, Strength and Aerobic Fitness in Aging Men

BACKGROUND

Based on the largely untested premise that it is a restorative hormone that may reverse the detrimental impacts of aging, prescription of testosterone (T) has increased in recent decades despite no new clinical indications. It is apparent that middle-aged and older men with low-normal serum T levels are considering T supplementation as an anti-aging strategy. At the same time, there is evidence that physical activity (PA) is at historical lows in the Western world. In this review, we compare the impacts of T treatment aimed at achieving physiological T concentrations in middle-aged and older men, alongside the impacts of ecologically relevant forms of exercise training. The independent, and possible combined, effects of T and exercise therapy on physiological outcomes such as aerobic fitness, body composition and muscular strength are addressed.

MAIN BODY

Our findings suggest that both T treatment and exercise improve lean body mass in healthy older men. If improvement in lean body mass is the primary aim, then T treatment could be considered, and the combination of T and exercise may be more beneficial than either in isolation. In terms of muscle strength in older age, an exercise program is likely to be more beneficial than T treatment (where the dose is aimed at achieving physiological concentrations), and the addition of such T treatment does not provide further benefit beyond that of exercise alone. For aerobic fitness, T at doses aimed at achieving physiological concentrations has relatively modest impacts, particularly in comparison to exercise training, and there is limited evidence as to additive effects. Whilst higher doses of T, particularly by intramuscular injection, may have larger impacts on lean body mass and strength, this must be balanced against potential risks.

CONCLUSION

Knowing the impacts of T treatment and exercise on variables such as body composition, strength and aerobic fitness extends our understanding of the relative benefits of physiological and pharmacological interventions in aging men. Our review suggests that T has impacts on strength, body composition and aerobic fitness outcomes that are dependent upon dose, route of administration, and formulation. T treatment aimed at achieving physiological T concentrations in middle-aged and older men can improve lean body mass, whilst exercise training enhances lean body mass, aerobic fitness and strength. Men who are physically able to exercise safely should be encouraged to do so, not only in terms of building lean body mass, strength and aerobic fitness, but for the myriad health benefits that exercise training confers.

Oleanolic acid alleviates obesity-induced skeletal muscle atrophy via the PI3K/Akt signaling pathway

Oleanolic acid (OA) is a pentacyclic triterpene with reported protective effects against various diseases, including diabetes, hepatitis, and different cancers. However, the effects of OA on obesity-induced muscle atrophy remain largely unknown. This study investigated the effects of OA on skeletal muscle production and proliferation of C2C12 cells. We report that OA significantly increased skeletal muscle mass and improved glucose intolerance and insulin resistance. OA inhibited dexamethasone (Dex)-induced muscle atrophy in C2C12 myoblasts by regulating the PI3K/Akt signaling pathway. In addition, it also inhibited expression of MuRF1 and Atrogin1 genes in skeletal muscle of obese mice suffering from muscle atrophy, and increased the activation of PI3K and Akt, thereby promoting protein synthesis, and eventually alleviating muscle atrophy. Taken together, these findings suggest OA may have potential for the prevention and treatment of muscle atrophy.

Concurrent training associated with moderate walnut consumption improved isokinetic strength, subjective sleep quality, cognitive performance and postural balance in elderly active men: a randomized controlled trial

AIMS

To investigate the effects of concurrent training (resistance and endurance) associated with moderate walnut consumption on isokinetic strength, subjective sleep quality, cognitive performance and postural balance in physically active elderly men.

METHODS

Twenty healthy elderly men were divided into two matched groups, in a randomized controlled experiment. They have participated in three training sessions per week: concurrent (strength and endurance) training + ad libitum diet with walnuts (15 g/day for 6 weeks, CTW: n = 10) and concurrent training + ad libitum diet (CT: n = 10). Isokinetic strength, Spiegel questionnaire, Montreal cognitive assessment and postural balance parameters were assessed 48 h pre- and post-intervention.

RESULTS

Absolute peak torque of knee extensors and knee flexors significantly increased compared to pre-training in CTW (15.2% ± 6.7; 13.2% ± 2.3, p < 0.05, respectively) and CT (10.6% ± 6.8; 7.4% ± 2.9, p < 0.05, respectively). Subjective sleep quality increased compared to pre-training for CTW and CT (24% ± 14.4; 10.5% ± 9.4, p < 0.05, respectively) with a significantly greater increase in CTW (p < 0.05). Cognitive performance measured by Montreal cognitive assessment (MoCA) increased only in CTW compared to baseline (7.7% ± 2.5, p < 0.05). Postural balance parameters with dual task decreased only in CTW compared to baseline.

CONCLUSIONS

The present study clearly revealed that concurrent training alone or associated with daily walnut (15 g) consumption for 6 weeks significantly increased knee isokinetic strength, support leg standing parameters and sleep quality. Meanwhile, cognitive performance evaluated by MoCA test and postural balance with dual task were improved for CTW group only.

Reducing meat and/or dairy consumption in adults: a systematic review and meta-analysis of effects on protein intake, anthropometric values, and body composition

CONTEXT

Consumers are increasingly encouraged to reduce meat and dairy consumption. However, few meta-analyses of randomized controlled trials (RCTs) on the effect of reducing meat and/or dairy on (absolute) protein intake, anthropometric values, and body composition are available.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effect of reducing meat and/or dairy consumption on (absolute) protein intake, anthropometric values, and body composition in adults aged ≥ 45 years.

DATA SOURCES

The MEDLINE, Cochrane CENTRAL, Embase, ClinicalTrials.gov, and International Clinical Trials Registry Platform databases were searched up to November 24, 2021.

DATA EXTRACTION

Randomized controlled trials reporting protein intake, anthropometric values, and body composition were included.

DATA ANALYSIS

Data were pooled using random-effects models and expressed as the mean difference (MD) with 95%CI. Heterogeneity was assessed and quantified using Cochran's Q and I2 statistics. In total, 19 RCTs with a median duration of 12 weeks (range, 4-24 weeks) and a total enrollment of 1475 participants were included. Participants who consumed meat- and/or dairy-reduced diets had a significantly lower protein intake than those who consumed control diets (9 RCTs; MD, -14 g/d; 95%CI, -20 to -8; I2 = 81%). Reducing meat and/or dairy consumption had no significant effect on body weight (14 RCTs; MD, -1.2 kg; 95%CI, -3 to 0.7; I2 = 12%), body mass index (13 RCTs; MD, -0.3 kg/m2; 95%CI, -1 to 0.4; I2 = 34%), waist circumference (9 RCTs; MD, -0.5 cm; 95%CI, -2.1 to 1.1; I2 = 26%), amount of body fat (8 RCTs; MD, -1.0 kg; 95%CI, -3.0 to 1.0; I2 = 48%), or lean body mass (9 RCTs; MD, -0.4 kg; 95%CI, -1.5 to 0.7; I2 = 0%).

CONCLUSION

Reduction of meat and/or dairy appears to reduce protein intake. There is no evidence of a significant impact on anthropometric values or body composition. More long-term intervention studies with defined amounts of meat and dairy are needed to investigate the long-term effects on nutrient intakes and health outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020207325.

Turning and sitting movements during timed up and go tests predict deterioration of physical function in middle-aged adults

BACKGROUND

Deterioration of physical function in middle-aged adults is a significant challenge that can lead to increased risk of future falls. However, a screening method for the functional decline in middle-aged adults has not been established.

RESEARCH QUESTION

To evaluate the relationship between biomechanical parameters assessed by the timed up and go test (TUG) and locomotive syndrome (LS) in middle-aged adults.

METHODS

The inclusion criterion was: under 65 years of age. A total of 97 volunteers (mean age 51.1 years) participated in this study. An LS test was performed, including a 2-step test, a stand-up test, and a 25-question Geriatric Locomotive Function Scale. The TUG was measured using inertial measurement units (IMUs) at comfortable and fast speeds. We then determined the minimum values for anterior-posterior acceleration and angular velocity around the medial-lateral axis, as well as the maximum values of angular velocity around the vertical axis for the upper trunk and sacrum in a TUG phase.

RESULTS

Angular velocity around the vertical axis for upper trunk and sacrum were significantly smaller in LS than non-LS in the turn phase of both speed conditions. For the fast speed condition, the minimum anterior-posterior acceleration for sacrum was greater in LS than in the non-LS condition for the stand-to-sit phase. Angular velocity around the vertical axis for turning and anterior-posterior acceleration from sitting were associated with detection of LS.

SIGNIFICANCE

Turning and sitting movements during TUG should be observed using IMU to screen for physical function decline in middle aged adults.

Diet quality is associated with adipose tissue and muscle mass: the Coronary Artery Risk Development in Young Adults (CARDIA) study

BACKGROUND

Aging is associated with changes in body composition, and preventing loss of muscle mass and accumulation of excess adipose tissue in middle-aged adults may reduce age-related conditions at older ages. Dietary intake is one lifestyle factor shown to improve or maintain body composition. However, few studies have examined the Healthy Eating Index2015 (HEI2015), a measure of diet quality, and the association with body composition in adult men and women.

METHODS

Participant data (n = 3017) from the Coronary Artery Risk Development in Young Adults (CARDIA) study were used to examine the associations of the HEI2015 with body composition measures at Year 25 (Y25), including (1) 25 year-change in weight, body mass index (BMI), and waist circumference and (2) a computed tomography (CT) scan at Y25 measured muscle mass, muscle quality (better quality = less lipid within the muscle), and adipose tissue depots visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and adipose within skeletal muscle (intermuscular adipose tissue; IMAT). Dietary intake was assessed by a diet history three times over 20 years, at years 0, 7, and 20. HEI2015, averaged over three exams, was created and categorized into quintiles. Multiple regression analysis evaluated the associations of body composition stratified across quintiles of HEI2015 adjusted for demographic characteristics, energy intake, lifestyle factors, and baseline anthropometric measures as appropriate. Race-sex interaction was tested (Pinteraction  > 0.30).

RESULTS

Over 25 years of follow-up, averaged HEI2015 was significantly and inversely associated with weight gain (Quintile 1 (Q1) 37.3 lb vs. 32.9 in Q5; Ptrend  = 0.01), change in BMI (Q1 5.8 kg/m2 vs. 5.0 in Q5; Ptrend  = 0.005), and change in waist circumference (Q1 17.5 cm vs. 15.2 cm in Q5; Ptrend  < 0.001). By Y25, HEI2015 was inversely associated with VAT Q1 136.8 cm3 vs. 116.6 in Q5; Ptrend  < 0.001) and IMAT volumes (Q1 9.52 vs. 8.12 cm3 in Q5; Ptrend  < 0.001). Although total muscle volume declined (Ptrend  = 0.03), lean muscle mass volume was similar across quintiles (Ptrend  = 0.55). The IMAT/total muscle mass ratio declined across HEI2015 quintiles (Ptrend  < 0.001). Finally, higher HEI2015 was associated with better muscle quality at Y25 (higher value = less lipid within the muscle; Q1 41.1 vs. 42.2 HU in Q5; Ptrend  = 0.002). HEI2015 was nonlinearly, but inversely, associated with SAT (nonlinear P = 0.011).

CONCLUSIONS

Improving diet quality in young to middle-aged adults is a recommended strategy to promote better measures of body composition. Our study findings suggest that healthier food choices may influence body composition.

Trunk postural control during unstable sitting among individuals with and without low back pain: A systematic review with an individual participant data meta-analysis

INTRODUCTION

Sitting on an unstable surface is a common paradigm to investigate trunk postural control among individuals with low back pain (LBP), by minimizing the influence lower extremities on balance control. Outcomes of many small studies are inconsistent (e.g., some find differences between groups while others do not), potentially due to confounding factors such as age, sex, body mass index [BMI], or clinical presentations. We conducted a systematic review with an individual participant data (IPD) meta-analysis to investigate whether trunk postural control differs between those with and without LBP, and whether the difference between groups is impacted by vision and potential confounding factors.

METHODS

We completed this review according to PRISMA-IPD guidelines. The literature was screened (up to 7th September 2023) from five electronic databases: MEDLINE, CINAHL, Embase, Scopus, and Web of Science Core Collection. Outcome measures were extracted that describe unstable seat movements, specifically centre of pressure or seat angle. Our main analyses included: 1) a two-stage IPD meta-analysis to assess the difference between groups and their interaction with age, sex, BMI, and vision on trunk postural control; 2) and a two-stage IPD meta-regression to determine the effects of LBP clinical features (pain intensity, disability, pain catastrophizing, and fear-avoidance beliefs) on trunk postural control.

RESULTS

Forty studies (1,821 participants) were included for the descriptive analysis and 24 studies (1,050 participants) were included for the IPD analysis. IPD meta-analyses revealed three main findings: (a) trunk postural control was worse (higher root mean square displacement [RMSdispl], range, and long-term diffusion; lower mean power frequency) among individuals with than without LBP; (b) trunk postural control deteriorated more (higher RMSdispl, short- and long-term diffusion) among individuals with than without LBP when vision was removed; and (c) older age and higher BMI had greater adverse impacts on trunk postural control (higher short-term diffusion; longer time and distance coordinates of the critical point) among individuals with than without LBP. IPD meta-regressions indicated no associations between the limited LBP clinical features that could be considered and trunk postural control.

CONCLUSION

Trunk postural control appears to be inferior among individuals with LBP, which was indicated by increased seat movements and some evidence of trunk stiffening. These findings are likely explained by delayed or less accurate corrective responses.

SYSTEMATIC REVIEW REGISTRATION

This review has been registered in PROSPERO (registration number: CRD42021124658).

The impact of Helicobacter pylori infection on low skeletal muscle mass risk in Chinese women over 40: a cross-sectional analysis

Background

Sarcopenia can lead to significant personal, social, and economic burdens. The diagnosis of sarcopenia heavily relies on the identification of Low Skeletal Muscle Mass (LSMM), which is an independent predictor of frailty, disability, and increased risk of death among seniors. Women have physiologically lower levels of skeletal muscle mass than men, and female sarcopenia appears to be more influenced by menopause. They also tend to have higher body fat levels than man, which increases the risk of sarcopenia obesity. On another front, it's also recognized that humans are largely prone to Helicobacter pylori (H. pylori) infection, with global prevalence rates often surpassing 50%. Nevertheless, the interconnection between H. pylori infection and LSMM remains relatively unexplored. Hence, our study specifically targeted women as the research population and sought to explore several risk factors for LSMM. Additionally, we delved into the potential correlation between LSMM and H. pylori infection in women, hoping to gain insights into potential preventative measures or treatment options that may enhance the quality of life for women affected by sarcopenia.

Methods

We conducted a cross-sectional study among women aged over 18 years undergoing physical examination. We performed 13C-urea breath test (UBT) for diagnosis of H. pylori infection and Bioelectrical impedance analysis (BIA) for the assessment of LSMM. Logistic regression models were used to analyze the associations of H. pylori infection with LSMM.

Results

This study enrolled 1984 Chinese women who were undergoing health check-ups. A univariate logistic regression analysis did not reveal a direct correlation between H. pylori infection and LSMM among this female population (OR=1.149, 95% CI 0.904-1.459, p=0.257). Yet, upon dividing the participants into age-based subgroups, an evident link was observed between H. pylori infection and LSMM in women aged 40 or above (OR=1.381, 95%CI 1.032-1.848, p= 0.030). After adjusting for variables including Age, BMI, TP, ALK, Cre, this relationship remained statistically relevant (OR=1.514, 95%CI 1.085-2.113, p= 0.015).

Conclusions

Women who are over 40 years old and currently infected with H. pylori have an increased risk of developing LSMM. Therefore, timely treatment for H. pylori eradication is recommended for this group of women to reduce the occurrence of LSMM.

Resistance training maintains physical function but does not prevent changes in body composition and biochemical markers after detraining in aging adults

OBJECTIVE

The objective of the present study was to analyze the effects of 10 weeks of resistance training (RT) and subsequent 4 weeks of detraining on physical function, body composition, and biochemical markers in aging adults.

METHODS

The study sample was selected by convenience and consisted of 12 women with a mean age of 58 ± 7 years. Physical function [Latin-American Group of Development for Maturity (GDLAM) general index], body composition, total and fractional cholesterol, triglycerides, and glycemia were assessed before and after RT (10 weeks) and detraining (4 weeks).

RESULTS

After 10 weeks of RT, there were improvements in fat-free mass (39.1 ± 4.2 vs. 39.9 ± 4.4 kg; p < 0.05 and d = 0.2), fat mass (39.9 ± 6.3% vs. 38.7 ± 6.4%; p < 0.05 and d = -0.2), conicity index (1.47 ± 0.07 vs. 1.43 ± 0.06; p = 0.001 and d = -0.6), and physical function (GDLAM index [27.2 ± 5.5 vs. 25.0 ± 4.7; p = 0.001 and d = -0.4]). Significant improvements were also found in total cholesterol (271.8 ± 75.7 vs. 217.2 ± 52.2 mg/dL; p < 0.01 and d = -0.8), LDL-cholesterol (196.5 ± 61.6 vs. 159.3 ± 38.5 mg/dL; p < 0.01 and d = -0.7), HDL-cholesterol (53.1 ± 7.3 vs. 64.3 ± 23.7 mg/dL; p < 0.05 and d = 0.7), and triglycerides (165.8 ± 32.6 vs. 139.9 ± 46.6 mg/dL; p = 0.001 and d = -0.6). After the detraining period, all benefits in physical function were successfully maintained.

CONCLUSION

RT provided benefits in physical function, body composition, and biochemical markers in aging adults. However, 4-week detraining impaired body composition and biochemical markers in the investigated sample.

Protocol of the MOVI-ageing randomized controlled trial: a home-based e-Health intervention of cognitively demanding exercise for the improvement of cardiorespiratory fitness and cognitive function in older individuals

Objective

To describe the protocol of the MOVI-ageing randomized controlled trial, a home-based eHealth intervention of cognitive-demanding exercise for older adults, in improving global cognitive function and basic cognitive functions, cardiorespiratory fitness, and muscle fitness.

Methods

This randomized controlled trial will include participants identified in the social centers of Cuenca and Talavera de la Reina who agree to participate and provide informed consent. Adults aged 60-80 years of both genders retired regardless of the reason for retirement, who do not meet frailty criteria according to Fried criteria, and without cognitive impairment will be invited to participate. This study will be developed in two phases: (i) a 12-week randomized efficacy/feasibility trial and (ii) a large-scale implementation randomized trial phase with a 12-week follow-up following similar procedures. In addition, a qualitative study on barriers to and facilitators of the implementation of the physical exercise intervention using eHealth for older people will be conducted. Participants will have access to a platform including videos of cognitively demanding physical exercise. The participants will be remotely and off-line guided through the physical exercise intervention, and the research team will be able to check the degree of compliance with the program and its correct execution. The participants will receive feedback on their compliance with the routines and reinforcement messages.

Implications

The implementations of the findings and their inclusion in guidelines may directly impact in older people's life, and relatives, through the prevention of morbidity and the reduction of years lost to disability. These benefits may be reflected in the reduction of economic expenditure by reducing the demand for social and health care services.

Ethics

The Clinical Research Ethics Committee of the 'Virgen de la Luz' Hospital in Cuenca approved the study protocol (registration number: 2022/PI3222). In addition, this protocol was previously registered in Clinicaltrials.gov (Number: NCT05928078).

The Integral Role of Magnesium in Muscle Integrity and Aging: A Comprehensive Review

Aging is characterized by significant physiological changes, with the degree of decline varying significantly among individuals. The preservation of intrinsic capacity over the course of an individual's lifespan is fundamental for healthy aging. Locomotion, which entails the capacity for independent movement, is intricately connected with various dimensions of human life, including cognition, vitality, sensory perception, and psychological well-being. Notably, skeletal muscle functions as a pivotal nexus within this intricate framework. Any perturbation in its functionality can manifest as compromised physical performance and an elevated susceptibility to frailty. Magnesium is an essential mineral that plays a central role in approximately 800 biochemical reactions within the human body. Its distinctive physical and chemical attributes render it an indispensable stabilizing factor in the orchestration of diverse cellular reactions and organelle functions, thereby rendering it irreplaceable in processes directly impacting muscle health. This narrative review offers a comprehensive exploration of the pivotal role played by magnesium in maintaining skeletal muscle integrity, emphasizing the critical importance of maintaining optimal magnesium levels for promoting healthy aging.

Chloroquine impairs maximal transdiaphragmatic pressure generation in old mice

Aging results in increased neuromuscular transmission failure and denervation of the diaphragm muscle, as well as decreased force generation across a range of motor behaviors. Increased risk for respiratory complications in old age is a major health problem. Aging impairs autophagy, a tightly regulated multistep process responsible for clearing misfolded or aggregated proteins and damaged organelles. In motor neurons, aging-related autophagy impairment may contribute to deficits in neurotransmission, subsequent muscle atrophy, and loss of muscle force. Chloroquine is commonly used to inhibit autophagy. We hypothesized that chloroquine decreases transdiaphragmatic pressure (Pdi) in mice. Old mice (16-28 mo old; n = 26) were randomly allocated to receive intraperitoneal chloroquine (50 mg/kg) or vehicle 4 h before measuring Pdi during eupnea, hypoxia (10% O2)-hypercapnia (5% CO2) exposure, spontaneous deep breaths ("sighs"), and maximal activation elicited by bilateral phrenic nerve stimulation (Pdimax). Pdi amplitude and ventilatory parameters across experimental groups and behaviors were evaluated using a mixed linear model. There were no differences in Pdi amplitude across treatments during eupnea (∼8 cm H2O), hypoxia-hypercapnia (∼10 cm H2O), or sigh (∼36 cm H2O), consistent with prior studies documenting a lack of aging effects on ventilatory behaviors. In vehicle and chloroquine-treated mice, average Pdimax was 61 and 46 cm H2O, respectively. Chloroquine decreased Pdimax by 24% compared to vehicle (P < 0.05). There were no sex or age effects on Pdi in older mice. The observed decrease in Pdimax suggests aging-related susceptibility to impairments in autophagy, consistent with the effects of chloroquine on this important homeostatic process.NEW & NOTEWORTHY Recent findings suggest that autophagy plays a role in the development of aging-related neuromuscular dysfunction; however, the contribution of autophagy impairment to the maintenance of diaphragm force generation in old age is unknown. This study shows that in old mice, chloroquine administration decreases maximal transdiaphragmatic pressure generation. These chloroquine effects suggest a susceptibility to impairments in autophagy in old age.

Mechanisms and effects of metformin on skeletal muscle disorders

Skeletal muscle disorders are mostly genetic and include several rare diseases. With disease progression, muscle fibrosis and adiposis occur, resulting in limited mobility. The long course of these diseases combined with limited treatment options affect patients both psychologically and economically, hence the development of novel treatments for neuromuscular diseases is crucial to obtain a better quality of life. As a widely used hypoglycemic drug in clinical practice, metformin not only has anti-inflammatory, autophagy-regulating, and mitochondrial biogenesis-regulating effects, but it has also been reported to improve the symptoms of neuromuscular diseases, delay hypokinesia, and regulate skeletal muscle mass. However, metformin's specific mechanism of action in neuromuscular diseases requires further elucidation. This review summarizes the evidence showing that metformin can regulate inflammation, autophagy, and mitochondrial biogenesis through different pathways, and further explores its mechanism of action in Duchenne muscular dystrophy, statin-associated muscle disorders, and age-related sarcopenia. This review clarifies the directions of future research on therapy for neuromuscular diseases.

Old muscle, new tricks: a clinician perspective on sarcopenia and where to next

PURPOSE OF REVIEW

This review offers a contemporary clinical approach to the recognition, prevention and management of sarcopenia, and discusses recent clinically relevant advances in the aetiopathogenesis of muscle ageing that may lead to future therapeutic targets.

RECENT FINDINGS

The key recent directions for sarcopenia are in the diagnosis, understanding molecular mechanisms and management. Regarding the recognition of the condition, it has become increasingly clear that different definitions hamper progress in understanding. Therefore, the Global Leadership in Sarcopenia has been established in 2022 to develop a universally accepted definition. Moreover, substantial work is occurring to understand the various roles and contribution of inflammation, oxidative stress, mitochondrial dysfunction and metabolic dysregulation on skeletal muscle function and ageing. Finally, the role of resistance-based exercise regimes has been continually emphasised. However, the role of protein supplementation and hormone replacement therapy (HRT) are still under debate, and current clinical trials are underway.

SUMMARY

With the global ageing of our population, there is increasing emphasis on maintaining good health. Maintenance of skeletal muscle strength and function are key to preventing frailty, morbidity and death.