The relationship between serum IGF-1, handgrip strength, physical performance and falls in elderly men and women

Dietary factors may be associated with measures of ultrasound-derived skeletal muscle echo intensity

Skeletal muscle echo intensity (EI) is affected by ageing and physical activity; however, the effects of nutrition are less understood. The aim of this study was to explore whether habitual nutrient intake may be associated with ultrasound-derived EI. Partial least squares regression (PLSR) models were trained on an initial sample (n = 100, M = 45; F = 55; 38 ± 15 years) to predict EI of two quadriceps muscles from 19 variables, using the "jack-knife" function within the "pls" package (RStudio), which was then tested in an additional dataset (n = 30, M = 13; F = 17; 38 ± 16 years). EI was determined using B-mode ultrasonography of the rectus femoris (RF) and vastus lateralis (VL) and nutritional intake determined via 3-day weighed food diaries. Mean daily intake of specific nutrients were included as predictor variables with age, sex, and self-reported physical activity. PLSR training model 1 explained ∼52% and model 2 ∼46% of the variance in RF and VL EI, respectively. Model 1 also explained ∼35% and model 2 ∼30% of the variance in RF and VL EI in the additional testing dataset. Age and biological sex were associated with EI in both models (P < 0.025). Dietary protein (RF: β = -7.617, VL: β = -7.480), and selenium (RF: β = -7.144, VL: β = -4.775) were associated with EI in both muscles (P < 0.05), whereas fibre intake (RF: β = -5.215) was associated with RF EI only and omega-3 fatty acids (n-3/ω-3 FAs, RF: β = 3.145) with VL EI only (P < 0.05). Therefore, absolute protein, selenium, fibre, and n-3 FAs may be associated with skeletal muscle EI, although further mechanistic work is required before claiming causal inference.

Sarcopenia and frailty among older Chinese adults: Findings from the CHARLS study

BACKGROUND

Sarcopenia and frailty are common among elderly individuals and present substantial health hazards. Exploring their relationship is essential for optimizing geriatric healthcare, particularly within the context of China.

METHODS

A population-based cross-sectional design was employed using data from the China Health and Retirement Longitudinal Study (CHARLS). The study enrolled 5,714 participants aged ≥60 years who underwent assessment for sarcopenia following the criteria established by the Asia Working Group for Sarcopenia (AWGS 2019) in 2019. Frailty status was determined using a frailty index that categorized participants into robustness, pre-frailty, and frailty stages. Multivariable logistic regression models were employed to examine the relationship between sarcopenia and frailty and pre-frailty conditions. Subgroup and interaction analyses were performed to explore the robustness of the associations between sarcopenia and frailty across different subgroups.

RESULTS

Among the participants, 1,028 (18.0%) were identified as frailty, 2,987 (52.3%) as pre-frailty, and 645 (11.3%) had sarcopenia. Sarcopenia demonstrated an independent association with higher risks of frailty (OR = 2.13, 95% CI: 1.52-2.99) and pre-frailty (OR = 1.42, 95% CI: 1.20-1.81) in the multivariable logistic analysis. Subgroup and interaction analyses consistently demonstrated significant associations across nearly all demographic and health-related subgroups.

CONCLUSIONS

This study highlights that sarcopenia is significantly and independently associated with frailty and pre-frailty among older adults in China. Early detection and targeted interventions for sarcopenia are crucial to mitigate frailty and its adverse health outcomes in aging populations, emphasizing the need for tailored healthcare strategies to promote healthy aging.

Causal associations between the insulin-like growth factor family and sarcopenia: a bidirectional Mendelian randomization study

Objective

Insulin-like growth factor (IGF) is closely associated with sarcopenia, yet the causal relationship of this association remains unclear. This study aims to explore the potential causal relationship between members of the IGF family and sarcopenia from a genetic perspective through bidirectional Mendelian randomization (MR) analysis using two-sample datasets.

Methods

Five genetically predicted factors of the IGF family (IGF-1, IGF-1R, IGF-2R, IGFBP-3, IGFBP-7) as one sample, while four relevant features of sarcopenia (low hand grip strength, appendicular lean mass, whole body fat-free mass, and walking pace) as another sample, in conducting a two-sample MR analysis.

Results

The forward MR results of the relationship between IGF and sarcopenia showed that elevated levels of IGF-1 reduced the risk of low hand grip strength (OR = 0.936, 95% CI=0.892-0.983, P = 0.008) and increased appendicular lean mass of the extremities and whole body fat-free mass (OR = 1.125, 95% CI=1.070-1.182,P = 0.000; OR =1.076, 95% CI=1.047-1.106, P=0.000), reduced the risk of sarcopenia. Elevated IGF-1R also favored an increase in whole body fat-free mass (OR=1.023, 95% CI=1.008-1.038, P =0.002), and the appendicular lean mass trait was more pronounced with elevated IGFBP-3 and IGFBP-7 (OR=1.034, 95% CI=1.024-1.044, P =0.000; OR=1.020, 95% CI=1.010-1.030, P=0.000). Inverse MR results of the effect of sarcopenia on IGF showed that decreased hand grip strength may elevate IGF-1 levels (OR=1.243, 95% CI=1.026-1.505,P =0.027), whereas improvements in appendicular lean mass, whole body fat-free mass traits, and increased walking pace decreased IGF-1 levels (OR=0.902, 95% CI: 0.877-0.927, P = 0.000; OR=0.903, 95% CI=0.859-0.949,P = 0.000; OR=0.209, 95% CI=0.051-0.862,P = 0.045). Also decreased hand grip strength may elevate IGF-1R levels (OR=1.454, 95% CI=1.108-1.909, P =0.007), and appendicular lean mass stimulated high expression of IGFBP-1 (OR=1.314, 95% CI=1.003-1.722, P =0.047). Heterogeneity and pleiotropy were not detected in all results, and the results were stable and reliable.

Conclusion

There is a bi-directional causal association between IGF family members and the risk of sarcopenia, which provides a more adequate basis for early biological monitoring of sarcopenia and may provide new targets for early intervention and treatment of sarcopenia.

The effect of low-intensity suspension training with blood flow restriction on GH, IGF-1, and their association with physical fitness in young women

Blood flow restriction (BFR) has been incorporated in resistance training for over 20 years. We aimed to investigate the impact of low-intensity suspension training with BFR (LIST+BFR) on GH, IGF-1, and their association with physical fitness in young women. Thirty-six active women participated and were randomly assigned to either the high-intensity suspension training (HIST), LIST+BFR, or control (CON) groups. Training groups exercised three sessions weekly for 8 weeks. The CON only engaged in regular physical activity. Fasting serum hormones and physical fitness were assessed 48 h before and after the training intervention. GH and IGF-1 levels significantly higher in the LIST+BFR compared to the HIST and CON. These hormones were significantly higher by HIST, compared to CON. LIST+BFR led to significant enhancements in muscular strength and endurance compared to HIST and CON. Additionally, HIST significantly higher than compared to CON. Sprinting and agility time lower in both suspension training groups rather than the CON. No significant between-groups differences were found in weight. There was a large or moderate correlation between GH and IGF-1 and muscular strength, endurance, sprint, and agility performance. LIST+BFR could more enhanced GH, IGF-1, and muscular strength and endurance in females than HIST.

The mediating role of lower body muscle strength and IGF-1 level in the relationship between age and cognition. A MIDUS substudy

OBJECTIVE

Aging is a natural process associated with a decline in cognition. However, the mediating effect of physical function and circulating myokines on this relationship has yet to be fully clarified. This study investigated how muscle strength and circulating insulin-like growth factor-1 (IGF-1) levels mediate the relationship between age and cognitive functions.

SUBJECTS AND METHODS

A total of 1255 participants aged 25-74 years included in the Midlife in the United States II study were retrospectively analyzed. In this cross-sectional analysis, we applied a serial mediation model to explore the mediating effects of muscle strength and circulating IGF-1 levels on the relationship between age and cognitive functions. We included potential confounding factors related to sociodemographics, lifestyle, and health status as covariates in the model.

RESULTS

The results showed that aging had both direct and indirect effects on cognition. As predicted, muscle strength and IGF-1 levels mediated the relationship between age and specific cognitive functions. In addition, mediation analyses indicated that the association between aging and cognitive flexibility, immediate and delayed memory, and inductive reasoning were partially mediated by muscle strength and IGF-1 levels in a serial manner.

CONCLUSIONS

Our study demonstrated the serial multiple mediation roles of muscle strength and IGF-1 levels on the relationship between age and specific cognitive functions. Further longitudinal research should be performed to confirm the serial mediation results.

Analysis of Risk Factors for the Association of Sarcopenia in Patients with Type 2 Diabetes Mellitus

Background

Previous studies have shown that the prevalence of sarcopenia in patients with type 2 diabetes mellitus (T2DM) has increased significantly over the years. However, the risk factors for the association of sarcopenia in patients with T2DM are unknown. Therefore, we attempted to investigate the risk factors through measurement and analysis of the patients' data from April 2020 to April 2022.

Methods

A total of 334 hospitalized patients with T2DM were divided into sarcopenia group (n=101) and non-sarcopenia group (n=233). Clinical factors were compared between the two groups and also between the two genders. Receiver operating characteristic curve (ROC) was used to analyze the ROC diagnostic ability of related factors in sarcopenia.

Results

(1) Among the 334 patients, the overall prevalence of sarcopenia was 30.2%; 41.3% in men and 20.1% in women. (2) The multifactorial logistic regression analysis showed that gender (specifically for men; OR=4.997, 95% CI: 2.611-9.564), low body mass index (BMI) (OR=1.525, 95% CI: 1.353-1.718), lower 25(OH)D levels (OR=1.076, 95% CI:1.036-1.117), and lower IGF-1 (OR=1.013, 95% CI:1.006-1.020) were independent risk factors (P < 0.05). (3) ROC curve analysis results showed that BMI, 25 (OH) D, IGF-1, and testosterone (for men) had predictive significance for sarcopenia with T2DM (P < 0.05). However, the AUC of 25 (OH) D, IGF-1 and testosterone (for men) were all <0.7, while the AUC of BMI and the combined factors were all >0.7, has great predictive significance.

Conclusion

The prevalence of sarcopenia in hospitalized patients with T2DM is higher in men than in women. Low BMI and lower serum levels of 25 (OH) D and IGF-1 are risk factors of sarcopenia in patients with T2DM. Low BMI, 25(OH)D, IGF-1, and testosterone (for men) all contributed to the prediction of sarcopenia, among which BMI and combined factors were more significant.

Potential Biomarkers of Resilience to Microgravity Hazards in Astronauts

Space exploration exposes astronauts to the unique environment of microgravity, which poses significant health challenges. Identifying biomarkers that can predict an individual's resilience to the stressors of microgravity holds great promise for optimizing astronaut selection and developing personalized countermeasures. This narrative review examines the principal health risks associated with microgravity and explores potential biomarkers indicative of resilience. The biomarkers being evaluated represent a broad spectrum of physiological domains, including musculoskeletal, neurological, immunological, gastrointestinal, cardiovascular, and cutaneous systems. Earth-based microgravity analogs, such as dry immersion and head-down tilt bed rest, may provide valuable platforms to validate candidate biomarkers. However, biomarker sensitivity and specificity must be further evaluated to ensure efficacy and reliability. Establishing a panel of biomarkers predictive of resilience to microgravity-induced health risks would significantly enhance astronaut health and mission success, especially for long-duration exploration missions. Insights gained may also translate to health conditions on Earth characterized by reduced physical activity and mechanical loading.

Relationship between muscle mass and muscle strength with physical performance in older adults: A systematic review

Background

Declining muscle mass is not always accompanied by declining muscle strength in older adults, challenging the notion that low muscle mass is the sole criterion for diagnosing sarcopenia.

Objective

This review aims to find out the relationships between muscle mass and muscle strength with physical performance in older adults.

Design

This article was a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

Data Sources and Methods

We do a systematic search of observational studies that are published between 2013 and August 2023 in PubMed, ScienceDirect, Sage journal, Tripdatabase, Cochrane Library, Embase, and CINAHL. Two reviewers selected and extracted data independently and an association measure was recorded from included studies.

Results

The review analyzed 17 observational studies conducted between 2013 and September 2023. The findings suggest that while declining muscle mass is often associated with sarcopenia, it may not always correspond to declining muscle strength in older individuals. The most common method used to measure muscle mass was bioelectrical impedance analysis, while handgrip strength was the predominant measure of muscle strength. Tests such as timed up and go and gait speed were used to assess physical performance.

Conclusions

Physical performance in older adults is significantly related to muscle strength, whereas the relationship between muscle mass and physical performance is either weak or negligible. Therefore, when evaluating physical performance in older individuals, focusing on muscle strength is more important than muscle mass alone.

Sarcopenia in Immune-Mediated Rheumatic Diseases-Review

INTRODUCTION

Sarcopenia is a condition characterized by decreased muscle strength and muscle mass, which can impact physical function. Sarcopenia develops as a consequence of age-related decline (primary sarcopenia) and has a major impact on physical, social, and emotional well-being. In addition, patients with rheumatic diseases may suffer from sarcopenia independently of aging (secondary sarcopenia). Exercise, pharmacological treatments, and nutritional supplementation are some of the strategies used for the management of sarcopenia in the general population. The aim of this review is to summarize the evidence around the prevalence and impact of sarcopenia in patients with rheumatic diseases.

CONCLUSIONS

From our review, we can state that sarcopenia is a common and prevalent condition among the rheumatic diseases. Furthermore, the impacts of sarcopenia are not well-appreciated, and the implementation of treatment strategies has not been widespread. Strategies such as exercise and some pharmacological treatments are effective in improving physical and functional impairment related to these conditions.

FUTURE RESEARCH DIRECTIONS IN THE FIELD

New pharmacological treatments are being actively studied and may contribute in the future to the management of sarcopenia.

A meta-analysis of the effect of probiotic administration on age-related sarcopenia

Global increase in the prevalence of age-related diseases, such as sarcopenia, highlights the need of recognizing agents that improve muscle health; however, the evidence synthesis on the impact of probiotic administration on sarcopenia is scarce. To summarize and evaluate findings regarding the effect of supplementation with probiotics on sarcopenia, this meta-analysis was conducted. Using databases, including PubMed, SCOPUS, ISI-Web of Science, and Cochrane Library, interventional studies were included if they investigate the effect of probiotic administration on at least one of the components of sarcopenia up to 6 October 2022. Risk of bias evaluation was conducted using the Cochrane quality assessment tool. The random-effects model which takes between-study variations into account was used to obtain the overall effect sizes. The STATA version 14.0 was used for statistical analyses. Overall, 17 studies were included. There was high certainty of evidence that probiotic supplementation has a beneficial effect on muscle mass (kg) (WMD: 0.55, 95% CI: 0.05, 1.05; I 2: 0.0%, p = .995), and muscle function (WMD: 0.13, 95% CI: 0.03, 0.23; I 2: 65.6%, p = .05). Moreover, administration of probiotics for more than 12 weeks significantly increased muscle strength (WMD: 1.16, 95% CI: 0.88, 1.44; I 2: 0.0%, p = .77). However, probiotic supplementation had no effect on anthropometric indices, including body mass index. Probiotic supplementation could improve muscle mass and muscle function in adults more than 55 years old. The beneficial effect of probiotics on muscle strength could appear after 12 weeks of supplementation.

Genetic and Epigenetic Sexual Dimorphism of Brain Cells during Aging

In recent years, much of the attention paid to theoretical and applied biomedicine, as well as neurobiology, has been drawn to various aspects of sexual dimorphism due to the differences that male and female brain cells demonstrate during aging: (a) a dimorphic pattern of response to therapy for neurodegenerative disorders, (b) different age of onset and different degrees of the prevalence of such disorders, and (c) differences in their symptomatic manifestations in men and women. The purpose of this review is to outline the genetic and epigenetic differences in brain cells during aging in males and females. As a result, we hereby show that the presence of brain aging patterns in males and females is due to a complex of factors associated with the effects of sex chromosomes, which subsequently entails a change in signal cascades in somatic cells.

Cell non-autonomous regulation of cerebrovascular aging processes by the somatotropic axis

Age-related cerebrovascular pathologies, ranging from cerebromicrovascular functional and structural alterations to large vessel atherosclerosis, promote the genesis of vascular cognitive impairment and dementia (VCID) and exacerbate Alzheimer's disease. Recent advances in geroscience, including results from studies on heterochronic parabiosis models, reinforce the hypothesis that cell non-autonomous mechanisms play a key role in regulating cerebrovascular aging processes. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) exert multifaceted vasoprotective effects and production of both hormones is significantly reduced in aging. This brief overview focuses on the role of age-related GH/IGF-1 deficiency in the development of cerebrovascular pathologies and VCID. It explores the mechanistic links among alterations in the somatotropic axis, specific macrovascular and microvascular pathologies (including capillary rarefaction, microhemorrhages, impaired endothelial regulation of cerebral blood flow, disruption of the blood brain barrier, decreased neurovascular coupling, and atherogenesis) and cognitive impairment. Improved understanding of cell non-autonomous mechanisms of vascular aging is crucial to identify targets for intervention to promote cerebrovascular and brain health in older adults.

Are Skeletal Muscle Changes during Prolonged Space Flights Similar to Those Experienced by Frail and Sarcopenic Older Adults?

Microgravity exposure causes several physiological and psychosocial alterations that challenge astronauts' health during space flight. Notably, many of these changes are mostly related to physical inactivity influencing different functional systems and organ biology, in particular the musculoskeletal system, dramatically resulting in aging-like phenotypes, such as those occurring in older persons on Earth. In this sense, sarcopenia, a syndrome characterized by the loss in muscle mass and strength due to skeletal muscle unloading, is undoubtedly one of the most critical aging-like adverse effects of microgravity and a prevalent problem in the geriatric population, still awaiting effective countermeasures. Therefore, there is an urgent demand to identify clinically relevant biological markers and to underline molecular mechanisms behind these effects that are still poorly understood. From this perspective, a lesson from Geroscience may help tailor interventions to counteract the adverse effects of microgravity. For instance, decades of studies in the field have demonstrated that in the older people, the clinical picture of sarcopenia remarkably overlaps (from a clinical and biological point of view) with that of frailty, primarily when referred to the physical function domain. Based on this premise, here we provide a deeper understanding of the biological mechanisms of sarcopenia and frailty, which in aging are often considered together, and how these converge with those observed in astronauts after space flight.

Correlation between parameters related to sarcopenia and gray matter volume in patients with mild to moderate Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease characterized by brain atrophy and closely correlated with sarcopenia. Mounting studies indicate that parameters related to sarcopenia are associated with AD, but some results show inconsistent. Furthermore, the association between the parameters related to sarcopenia and gray matter volume (GMV) has rarely been explored.

AIM

To investigate the correlation between parameters related to sarcopenia and cerebral GMV in AD.

METHODS

Demographics, neuropsychological tests, parameters related to sarcopenia, and magnetic resonance imaging (MRI) scans were collected from 42 patients with AD and 40 normal controls (NC). Parameters related to sarcopenia include appendicular skeletal muscle mass index (ASMI), grip strength, 5-times sit-to-stand (5-STS) time and 6-m gait speed. The GMV of each cerebral region of interest (ROI) and the intracranial volume were calculated by computing the numbers of the voxels in the specific region based on MRI data. Partial correlation and multivariate stepwise linear regression analysis explored the correlation between different inter-group GMV ratios in ROIs and parameters related to sarcopenia, adjusting for covariates.

RESULTS

The 82 participants included 40 NC aged 70.13 ± 5.94 years, 24 mild AD patients aged 73.54 ± 8.27 years and 18 moderate AD patients aged 71.67 ± 9.39 years. Multivariate stepwise linear regression showed that 5-STS time and gait speed were correlated with bilateral hippocampus volume ratios in total AD. Grip strength was associated with the GMV ratio of the left middle frontal gyrus in mild AD and the GMV ratios of the right superior temporal gyrus and right hippocampus in moderate AD. However, ASMI did not have a relationship to any cerebral GMV ratio.

CONCLUSIONS

Among parameters related to sarcopenia, 5-STS time and gait speed were associated with bilateral hippocampus volume ratios at different clinical stages of patients with AD. Five-STS time provide an objective basis for early screening and can help diagnose patients with AD.

Extra Virgin Olive Oil (EVOO), a Mediterranean Diet Component, in the Management of Muscle Mass and Function Preservation

Aging results in a progressive decline in skeletal muscle mass, strength and function, a condition known as sarcopenia. This pathological condition is due to multifactorial processes including physical inactivity, inflammation, oxidative stress, hormonal changes, and nutritional intake. Physical therapy remains the standard approach to treat sarcopenia, although some interventions based on dietary supplementation are in clinical development. In this context, thanks to its known anti-inflammatory and antioxidative properties, there is great interest in using extra virgin olive oil (EVOO) supplementation to promote muscle mass and health in sarcopenic patients. To date, the molecular mechanisms responsible for the pathological changes associated with sarcopenia remain undefined; however, a complete understanding of the signaling pathways that regulate skeletal muscle protein synthesis and their behavior during sarcopenia appears vital for defining how EVOO might attenuate muscle wasting during aging. This review highlights the main molecular players that control skeletal muscle mass, with particular regard to sarcopenia, and discusses, based on the more recent findings, the potential of EVOO in delaying/preventing loss of muscle mass and function, with the aim of stimulating further research to assess dietary supplementation with EVOO as an approach to prevent or delay sarcopenia in aging individuals.

Serum IGF-1 levels are associated with sarcopenia in elderly men but not in elderly women

BACKGROUND

Sarcopenia is an age-associated decline in muscle mass that negatively affects the metabolic rate, strength, and function of the body and ultimately leads to a decrease in quality of life. Insulin-like growth factor 1 (IGF-1) is a modulator of muscle mass and muscle function. There is evidence that IGF-1 is related to the appendicular skeletal muscle mass index (ASMI) and grip strength. The aim of this study was to explore the relationship between serum IGF-1 levels and sarcopenia in older people.

METHODS

In this cross-sectional survey of 984 people older than 60 years old, we used the 2019 criteria of the Asian Working Group for Sarcopenia (AWGS) to define sarcopenia. We collected demographic variables, measured ASMI and grip strength, and detected serum IGF-1 data. The levels of serum IGF-1 were separated into quintiles (Q1-Q5).

RESULTS

Adjusted for age, education level, smoking, number of diseases and BMI, the multivariable linear regression analysis revealed that serum IGF-1 levels were related to ASMI in elderly men (coefficient = 0.03, 95% CI = 0.02-0.05, P < 0.001) but were not related to their grip strength. There was no significant relationship between serum IGF-1 levels and ASMI or grip strength in elderly women. The multivariable log-binomial regression analysis showed that higher serum IGF-1 levels were associated with a lower prevalence of sarcopenia in elderly men (prevalence ratio (PR) = 0.99, 95% CI = 0.98-1.00, P < 0.05) but not in elderly women.

CONCLUSION

Serum IGF-1 levels were highly correlated with sarcopenia in older men. Further studies are needed to further explore the possible reasons for the observed difference between genders. Serum IGF-1 might predict sarcopenia prevalence in elderly men.

Contribution of muscle satellite cells to sarcopenia

Sarcopenia, a disorder characterized by age-related muscle loss and reduced muscle strength, is associated with decreased individual independence and quality of life, as well as a high risk of death. Skeletal muscle houses a normally mitotically quiescent population of adult stem cells called muscle satellite cells (MuSCs) that are responsible for muscle maintenance, growth, repair, and regeneration throughout the life cycle. Patients with sarcopenia are often exhibit dysregulation of MuSCs homeostasis. In this review, we focus on the etiology, assessment, and treatment of sarcopenia. We also discuss phenotypic and regulatory mechanisms of MuSC quiescence, activation, and aging states, as well as the controversy between MuSC depletion and sarcopenia. Finally, we give a multi-dimensional treatment strategy for sarcopenia based on improving MuSC function.

Associations of Serum Insulin-Like Growth Factor 1 with New Cardiovascular Events and Subsequent Death in Hemodialysis Patients: The DREAM Cohort

AIM

Patients with chronic kidney disease (CKD) have elevated risk of death from cardiovascular disease (CVD). A low serum insulin-like growth factor 1 (IGF-1) level is known to predict higher risk for all-cause mortality in incident dialysis patients, although it is unknown whether IGF-1 predicts cardiovascular outcomes.

METHODS

This was a prospective cohort study of maintenance hemodialysis patients followed up for 5 years. Serum IGF-1 levels were measured at baseline, and patients were divided into IGF-1 tertiles. The key outcomes were all-cause mortality, a composite of new CVD, and death after new CVD events. Additional outcomes were hospitalization for infection and subsequent death. Association was analyzed using Cox proportional hazards models.

RESULTS

In the 516 patients that were analyzed, we identified 106 all-cause deaths, 190 new CVD events, and 61 subsequent deaths. In addition, there were 169 hospitalizations for infection and 47 subsequent deaths. The risk of all-cause death was the highest in the lowest IGF-1 tertile, and this association remained significant in multivariable-adjusted models. Regarding CVD outcomes, IGF-1 was not associated with new CVD events but significantly associated with subsequent death in adjusted models. Similarly, IGF-1 was not an independent predictor of hospitalization for infection, but it predicted subsequent death.

CONCLUSIONS

A low IGF-1 level was not a significant predictor of new CVD events but an independent predictor of subsequent death in hemodialysis patients. Since similar associations with infection outcomes were observed, IGF-1 may be a biomarker of fragility or frailty in this population.

Physiological Systems in Promoting Frailty

Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD+ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.

Sarcopenia: An Age-Related Multifactorial Disorder

Sarcopenia is an emerging clinical entity characterized by a gradual decline in skeletal muscle mass and strength that accompanies the normal aging process. It has been noted that sarcopenia is associated with various adverse health outcomes in the geriatric population like prolonged hospital admission, disability, poor quality of life, frailty, and mortality. Factors involved in the development of age-related sarcopenia include anorexia, alteration in the hormone levels, decreased neural innervation, low blood flow to the muscles, cytokine dysregulation, altered mitochondrial activity, genomic instability, intracellular proteolysis, and insulin resistance. Understanding the mechanism may help develop efficient preventive and therapeutic strategies which can improve the quality of life in elderly individuals. Thus, the objective of the present article is to review the literature regarding the mechanism involved in the development of sarcopenia in aged individuals.

Effects of hormonal changes on sarcopenia in chronic kidney disease: where are we now and what can we do?

Sarcopenia or muscle wasting is a progressive and generalized skeletal muscle disorder involving the accelerated loss of muscle mass and function, often associated with muscle weakness (dynapenia) and frailty. Whereas primary sarcopenia is related to ageing, secondary sarcopenia happens independent of age in the context of chronic disease states such as chronic kidney disease (CKD). Sarcopenia has become a major focus of research and public policy debate due to its impact on patient's health-related quality of life, health-care expenditure, morbidity, and mortality. The development of sarcopenia in patients with CKD is multifactorial and it may occur independently of weight loss or cachexia including under obese sarcopenia. Hormonal imbalances can facilitate the development of sarcopenia in the general population and is a common finding in CKD. Hormones that may influence the development of sarcopenia are testosterone, growth hormone, insulin, thyroid hormones, and vitamin D. Although the relationship between free testosterone level that is low in uraemic patients and sarcopenia in CKD is not well-defined, functional improvement may be seen. Unlike testosterone, it is known that vitamin D is associated with muscle strength, muscle size, and physical performance in patients with CKD. Outcomes after vitamin D replacement therapy are still controversial. The half-life of growth hormone (GH) is prolonged in patients with CKD. Besides, IGF-1 levels are normal in patients with Stage 4 CKD-a minimal reduction is seen in the end-stage renal disease. Unresponsiveness or resistance of IGF-1 and changes in the GH/IGF-1 axis are the main causes of sarcopenia in CKD. Low serum T3 level is frequent in CKD, but the net effect on sarcopenia is not well-studied. CKD patients develop insulin resistance (IR) from the earliest period even before GFR decline begins. IR reduces glucose utilization as an energy source by hepatic gluconeogenesis, decreasing muscle glucose uptake, impairing intracellular glucose metabolism. This cascade results in muscle protein breakdown. IR and sarcopenia might also be a new pathway for targeting. Ghrelin, oestrogen, cortisol, and dehydroepiandrosterone may be other players in the setting of sarcopenia. In this review, we mainly examine the effects of hormonal changes on the occurrence of sarcopenia in patients with CKD via the available data.

Genetically predicted insulin-like growth factor-I in relation to muscle mass and strength

OBJECTIVE

Insulin-like growth factor I (IGF-I) has been associated with muscle status in animal- and population-based studies. We conducted a Mendelian randomisation study to assess the causality of the associations of IGF-I with muscle strength and mass.

DESIGN AND PATIENTS

Genetic variants associated with serum IGF-I at genome-wide significance in the UK Biobank study (358,072 individuals of European descent) were selected as instrumental variables. Summary-level data on the associations of those variants with muscle weakness (low-grip strength) and muscle mass (fat-free body mass) were available from a meta-analysis of 22 genome-wide association studies including 46,596 cases and 209,927 noncases and genome-wide association analysis in 155,961 individuals from the UK Biobank study, respectively. The univariable and multivariable inverse-variance weighted methods were used.

RESULTS

Higher genetically predicted IGF-I levels were associated with a reduced risk of muscle weakness and increased muscle mass. For one standard deviation increase in genetically predicted IGF-I levels, the odds ratio was 0.92 (95% confidence interval [CI], 0.88, 0.97; p = .001) for muscle weakness and the change was 0.53 (95% CI: 0.28, 0.79; p < .001) kg for muscle mass. In the multivariable model with adjustment for genetically predicted height, the associations were attenuated but persisted for both muscle weakness (odds ratio: 0.95, 95% CI: 0.91, 0.99; p = .015) and muscle mass (change: 0.25, 95% CI: 0.10, 0.40; p = .001).

CONCLUSION

This study suggests that high IGF-I levels may decrease the risk of muscle weakness and loss.

Understanding Choline Bioavailability and Utilization: First Step Toward Personalizing Choline Nutrition

Choline is an essential macronutrient involved in neurotransmitter synthesis, cell-membrane signaling, lipid transport, and methyl-group metabolism. Nevertheless, the vast majority are not meeting the recommended intake requirement. Choline deficiency is linked to nonalcoholic fatty liver disease, skeletal muscle atrophy, and neurodegenerative diseases. The conversion of dietary choline to trimethylamine by gut microbiota is known for its association with atherosclerosis and may contribute to choline deficiency. Choline-utilizing bacteria constitutes less than 1% of the gut community and is modulated by lifestyle interventions such as dietary patterns, antibiotics, and probiotics. In addition, choline utilization is also affected by genetic factors, further complicating the impact of choline on health. This review overviews the complex interplay between dietary intakes of choline, gut microbiota and genetic factors, and the subsequent impact on health. Understanding of gut microbiota metabolism of choline substrates and interindividual variability is warranted in the development of personalized choline nutrition.

IGF-I/IGFBP3/ALS Deficiency in Sarcopenia: Low GHBP Suggests GH Resistance in a Subgroup of Geriatric Patients

CONTEXT

Definition of etiological subgroups of sarcopenia may help to develop targeted treatments. insulin like growth factor-I (IGF-I), Insulinlike growth factor binding protein 3 (IGFBP3), and acid labile subunit (ALS) build a ternary complex that mediates growth hormone (GH) effects on peripheral organs, such as muscle. Low GH binding protein (GHBP) as a marker of GH receptor number would hint toward GH resistance.

OBJECTIVE

We aimed to analyze the association of IGF-I, IGFBP3, and ALS with sarcopenia.

STUDY PARTICIPANTS AND SETTING

A total of 131 consecutively recruited patients of a geriatric ward were included in a single-center cross-sectional analysis; the nonsarcopenic patients served as controls.

METHODS

Measures included sarcopenia status by hand-grip strength measurement and Skeletal Muscle Index (SMI); IGF-I, IGFBP3, ALS, GH, GHBP; body mass index (BMI); Activity of Daily Living (ADL); Mini-Mental State Examination (MMSE); routine laboratory parameters; and statistical regression modeling.

RESULTS

Compared with controls, sarcopenic patients did not differ regarding age, sex, ADL, MMSE, C-reactive protein, glomerular filtration rate, and albumin serum concentrations. However, sarcopenic patients had significantly lower IGF-I, IGFBP3, and ALS. IGF-I and ALS associated significantly with sarcopenia and low hand-grip strength, even after adjustment for age, sex, BMI, and albumin, but not with low SMI. GHBP serum was low in sarcopenic patients, but normal in geriatric patients without sarcopenia. Over 60% of patients with IGF-I/ALS deficiency patients showed GH resistance.

CONCLUSIONS

Our data suggest that in geriatric patients, low IGF-I/IGFBP3/ALS could be evaluated for causative connection of the sarcopenia spectrum. Low GHBP points toward potential GH resistance as one possible explanation of this deficiency.

Lower albumin levels are associated with frailty measures, trace elements, and an inflammation marker in a cross-sectional study in Tanushimaru

Background

There is little data on the association between the lower nutrition represented by serum albumin levels and related factors in a general population. The present study aimed to determine whether the albumin level positioned as some kind of biomarker with frailty measures, trace elements, and an inflammation marker.

Methods

In 2018, we performed an epidemiological survey in 1368 subjects who resided in Tanushimaru, Japan, in which we examined the blood chemistry including albumin, trace elements, hormone levels, and carotid ultrasonography. Albumin levels were categorized into 4 groups (G1 [3.2–3.9 mg/dL], G2 [4.0–4.3 mg/dL], G3 [4.4–4.6 mg/dL], and G4 [4.7–5.3 mg/dL]). The participants underwent measurements of handgrip strength and were tested by asking to walk 5 m. Their cognitive functions were evaluated by the mini-mental state examination (MMSE).

Results

Multiple stepwise regression analysis demonstrated that albumin levels were significantly and independently associated with age (inversely), systolic blood pressures, estimated glomerular filtration rate (eGFR), MMSE score, frailty measures (handgrip strength), an inflammation marker (high-sensitivity C-reactive protein), hormones (growth hormone (inversely) and insulin-like growth factor-1), and trace elements (calcium, magnesium, iron, and zinc), with a linear trend.

Conclusions

Lower albumin levels, even in the normal range, were found to be related factors of frailty measures, trace elements, and an inflammation marker in a general population.

Impacts of frailty on health care costs among community-dwelling older adults: A meta-analysis of cohort studies

BACKGROUND

The demands for health care services from the frail elderly individuals in the community continue to increase, which will exert a tremendous burden on health care costs. However, little is known regarding the magnitude of these impacts. In this study, we performed a systematic review and meta-analysis of the evidence to explore the impact of frailty on health care costs among community-dwelling older adults.

MATERIALS AND METHODS

Relevant published articles were searched from PubMed, Embase, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journal Full-text Database (VIP), Wanfang Database, Chinese Biomedical Literature Database (CBM), and the reference lists of articles. Published cohort or cross-sectional studies assessing the impacts of frailty on health care costs among community-dwelling older adults were identified (to June 2020). The outcomes on health care costs before and after baseline were stratified by frailty status.

RESULTS

A total of 7 cohort studies comprised of a total of 3,750,611 participants were included in our study. Our analyses showed that: (1) compared with the robust group, health care costs increased by $79-13,423.83 (standardized mean difference, SMD = 0.22, 95% Confidence interval, 95% CI, 0.22-0.22; P < 0.00001) in the pre-frail elderly and by $616-32,549.96 (SMD = 0.55, 95% CI, 0.44-0.67; P < 0.00001) in the frail elderly in the community. A significantly higher in the increase of health care costs was observed in the frail group compared with the pre-frail group(SMD = 0.35, 95% CI, 0.19-0.51; P < 0.0001); (2) the frailty phenotype components increased the health care costs of the elderly in community (weight loss: $1,630-6,209, SMD = 0.43, 95% CI, 0.17-0.69; P = 0.001; weakness: $275-7,586, SMD = 0.24, 95% CI, 0.08-0.40; P = 0.001; exhaustion: $1,545-10,559, SMD = 0.31, 95% CI, 0.13-0.49; P = 0.0006; slowness: $352-1,1891, SMD = 0.40, 95% CI = 0.14-0.65; P = 0.003; low physical activity: $512-3,459, SMD = 0.26, 95% CI, 0.16-0.36; P < 0.00001); (3) the increase in the frailty index was parallel with the increase in health care costs by $12,363-21,066 (SMD = 0.41, 95% CI, 0.29-0.53; P < 0.00001).

CONCLUSIONS AND IMPLICATIONS

This study revealed the adverse economic impacts of frailty status, frailty phenotype components, and frailty index on health care costs in community-dwelling older adults. Future research is warranted to investigate costs incurred by interventions to improve frailty, which will provide further insights into additional health care costs due to frailty.

Links Between Testosterone, Oestrogen, and the Growth Hormone/Insulin-Like Growth Factor Axis and Resistance Exercise Muscle Adaptations

Maintenance of skeletal muscle mass throughout the life course is key for the regulation of health, with physical activity a critical component of this, in part, due to its influence upon key hormones such as testosterone, estrogen, growth hormone (GH), and insulin-like growth factor (IGF). Despite the importance of these hormones for the regulation of skeletal muscle mass in response to different types of exercise, their interaction with the processes controlling muscle mass remain unclear. This review presents evidence on the importance of these hormones in the regulation of skeletal muscle mass and their responses, and involvement in muscle adaptation to resistance exercise. Highlighting the key role testosterone plays as a primary anabolic hormone in muscle adaptation following exercise training, through its interaction with anabolic signaling pathways and other hormones via the androgen receptor (AR), this review also describes the potential importance of fluctuations in other hormones such as GH and IGF-1 in concert with dietary amino acid availability; and the role of estrogen, under the influence of the menstrual cycle and menopause, being especially important in adaptive exercise responses in women. Finally, the downstream mechanisms by which these hormones impact regulation of muscle protein turnover (synthesis and breakdown), and thus muscle mass are discussed. Advances in our understanding of hormones that impact protein turnover throughout life offers great relevance, not just for athletes, but also for the general and clinical populations alike.

Can Age Influence Functional Tests Differently to Predict Falls in Nursing Home and Community-Dwelling Older Adults?

Aim: The aim of this cross-sectional study was to determine which functional tests are able to predict falls in nursing home residents (NHR) and community-dwelling (CDW) older adults grouped by age. Methods: Two hundred and fifty-two older adults were assessed in the following tests, Mini-Mental State Examination, anthropometric characteristics, fall history and functional tests. The participants were assigned to one of the following groups: Young Older Adults (YOA; 60-69 years, n = 102; 27.5% NHR), Old Older Adults (OOA; 70-79 years; n = 100; 23.5% NHR) and Very Older Adults (VOA, ≥80 years; n = 50; 52% NHR). Results: The five times sit-to-stand showed 1.41 odds to experience a fall in the NHR of the VOA. In the CDW, the handgrip strength score decreased the odds to fall occurrence (0.92 odds) in the YOA, while the low score in timed up and go test of the OOA showed 1.21 odds to experience a fall. Conclusions: Therefore, the five times sit-to-stand test can predict falls in NHR of VOA groups, while handgrip strength and timed up and go tests can predict falls in CDW of YOA and OOA groups, respectively.

High Serum Tumor Necrosis Factor Receptor 1 Levels Are Related to Risk of Low Intrinsic Capacity in Elderly Adults

OBJECTIVES

To explore the association between inflammatory cytokines and intrinsic capacity in older adults.

METHOD

Data were retrieved from the Cardiovascular Health, Cognition and Aging Study. A total of 130 participants aged 60-99 years (mean age 73.11±9.02 years) were recruited. Intrinsic capacity was assessed by the five domains recommended by the World Health Organization: locomotion, cognition, vitality, sensory and psychological domains. Circulating interleukin-6, tumor necrosis factor receptor 1 (TNFR1), insulin-like growth factor-1, and vaspin levels were measured. Logistic regression was conducted for factors associated with intrinsic capacity decline.

RESULTS

Intrinsic capacity decline was associated with older age, kidney diseases, olfactory disturbances and lower grip strength. Logistic regression showed that circulating TNFR1 was independently associated with intrinsic capacity decline after adjustments for age, sex, education, chronic diseases, grip strength, and physical activity.

CONCLUSION

Elevated circulating TNFR1 levels are independently associated with declined intrinsic capacity, suggesting that chronic inflammation may underlie intrinsic capacity decline.

Food restriction reduces cortical bone mass and serum insulin-like growth factor-1 levels and promotes uterine atrophy in mice

Low energy availability in female athletes often causes hypothalamic amenorrhea and osteoporosis, in turn promoting stress fractures. Mechanisms underlying these conditions remain unclear. Here we show that model mice subjected to food restriction (FR) or FR-plus-voluntary running exercise exhibit significantly reduced bone mineral density, cortical bone parameters and uterine weight than do control mice, and that these parameters worsen in the FR-plus-exercise group. Relative to controls, FR and FR-plus-exercise groups showed significantly lower mineral apposition rate and osteoclast number and significantly reduced serum insulin-like growth factor-1 (IGF1) levels. Outcomes were rescued by ED71 or 1.25(OH)2D3 treatment. Thus, we conclude that administration of active vitamin D analogues represents a possible treatment to prevent these conditions.

Sarcopenia - Molecular mechanisms and open questions

Sarcopenia represents a muscle-wasting syndrome characterized by progressive and generalized degenerative loss of skeletal muscle mass, quality, and strength occurring during normal aging. Sarcopenia patients are mainly suffering from the loss in muscle strength and are faced with mobility disorders reducing their quality of life and are, therefore, at higher risk for morbidity (falls, bone fracture, metabolic diseases) and mortality. Several molecular mechanisms have been described as causes for sarcopenia that refer to very different levels of muscle physiology. These mechanisms cover e. g. function of hormones (e. g. IGF-1 and Insulin), muscle fiber composition and neuromuscular drive, myo-satellite cell potential to differentiate and proliferate, inflammatory pathways as well as intracellular mechanisms in the processes of proteostasis and mitochondrial function. In this review, we describe sarcopenia as a muscle-wasting syndrome distinct from other atrophic diseases and summarize the current view on molecular causes of sarcopenia development as well as open questions provoking further research efforts for establishing efficient lifestyle and therapeutic interventions.

Low Serum Branched-Chain Amino Acid and Insulin-Like Growth Factor-1 Levels Are Associated with Sarcopenia and Slow Gait Speed in Patients with Liver Cirrhosis

Branched-chain amino acid (BCAA) and insulin-like growth factor 1 (IGF-1) are essential for muscle protein synthesis. We investigated the association of serum BCAA and IGF-1 levels with sarcopenia and gait speed in 192 patients with liver cirrhosis (LC). Sarcopenia was diagnosed according to the Japan Society of Hepatology criteria. Slow gait speed was defined as <1.0 m/s. Subjects were divided into three groups based on baseline BCAA or IGF-1 levels: low (L), intermediate (I), and high (H) groups. The L-BCAA group had the highest prevalence of sarcopenia (60.4%, p < 0.001) and slow gait speed (56.3%, p = 0.008), whereas the H-BCAA group had the lowest prevalence of sarcopenia (8.5%, p < 0.001). The L-IGF-1 group showed the highest prevalence of sarcopenia (46.9%, p < 0.001), whereas the H-IGF-1 group had the lowest prevalence of sarcopenia (10.0%, p < 0.001) and slow gait speed (18.0%, p = 0.003). Using the optimal BCAA and IGF-1 cutoff values for predicting sarcopenia (372 μmol/L and 48.5 ng/mL, respectively), the sensitivity and specificity were 0.709 and 0.759 for BCAA and 0.636 and 0.715 for IGF-1, respectively. Low serum BCAA and IGF-1 levels were associated with sarcopenia and slow gait speed in patients with LC.

Effects of Progressive Resistance Training on Cognition and IGF-1 Levels in Elder Women Who Live in Areas with High Air Pollution

The aim of this study was to determine the effects of a muscular strength programme on the levels of insulin-like growth factor-1 (IGF-1) and cognitive status in elder women with mild cognitive impairment who lived in areas of high air pollution. A total of 157 women participated in the study, distributed in four groups: Active/Clean (AC n = 38) and Active/Pollution (AP n = 37), who carried out a progressive resistance training programme for 24 months, and Sedentary/Clean (SC n = 40) and Sedentary/Pollution (SP n = 42). Maximum strength in the upper and lower limbs (1RM), cognition (Mini-Mental Scale Examination (MMSE)) and blood IGF-1 were evaluated. At the beginning of the intervention, there were no differences between the groups in the assessed variables. The active groups which carried out the resistance training programme (AC and AP), registered better results in IGF-1 than the sedentary groups. These differences were statistically significant in AC vs. SC (p < 0.01) and AP vs. SC (p < 0.05). Regarding MMSE, group AC registered the highest score increases (+8.2%) (significantly better than the other groups), while group SP worsened (−7%) significantly compared to the other three groups. In conclusion, resistance training had a positive effect on IGF-1, while sedentary behaviour and air pollution had a negative effect on cognitive status.

Implications of Insulin-Like Growth Factor-1 in Skeletal Muscle and Various Diseases

Skeletal muscle is an essential tissue that attaches to bones and facilitates body movements. Insulin-like growth factor-1 (IGF-1) is a hormone found in blood that plays an important role in skeletal myogenesis and is importantly associated with muscle mass entity, strength development, and degeneration and increases the proliferative capacity of muscle satellite cells (MSCs). IGF-1R is an IGF-1 receptor with a transmembrane location that activates PI3K/Akt signaling and possesses tyrosine kinase activity, and its expression is significant in terms of myoblast proliferation and normal muscle mass maintenance. IGF-1 synthesis is elevated in MSCs of injured muscles and stimulates MSCs proliferation and myogenic differentiation. Mechanical loading also affects skeletal muscle production by IGF-1, and low IGF-1 levels are associated with low handgrip strength and poor physical performance. IGF-1 is potentially useful in the management of Duchenne muscular dystrophy, muscle atrophy, and promotes neurite development. This review highlights the role of IGF-1 in skeletal muscle, its importance during myogenesis, and its involvement in different disease conditions.

Choline: An Essential Nutrient for Skeletal Muscle

BACKGROUND

Choline is an essential micronutrient with a pivotal role in several metabolic pathways contributing to liver, neurological, and hematological homeostasis. Although choline is commonly administered to improve physical performance, its effects on muscle are still unclear. The aim of this scoping review is to analyze the role of choline on skeletal muscle in terms of biological effects and clinical implications.

METHODS

A technical expert panel (TEP) of 6 medical specialists with expertise in muscle physiology and skeletal muscle disorders performed the review following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) model. The TEP planned a research on PubMed selecting "choline" as MeSH (Medical Subject Headings) term adding to PubMed Search Builder the terms "skeletal muscle" and "muscle striated". TEP considered for eligibility articles published in the last 30 years, including original researches, particularly in vitro studies, and animal and clinical studies in the English language.

RESULTS

From the 1239 studies identified, TEP included 14 studies, 3 in vitro, 9 animal, and 2 clinical studies.

CONCLUSIONS

Our scoping review elucidates and summarizes the crucial role of choline in modulating muscle fat metabolism, muscle proteins homeostasis, and the modulation of inflammation and autophagy.

Understanding the Physiological Links Between Physical Frailty and Cognitive Decline

Declines in both physical and cognitive function are associated with increasing age. Understanding the physiological link between physical frailty and cognitive decline may allow us to develop interventions that prevent and treat both conditions. Although there is significant epidemiological evidence linking physical frailty to cognitive decline, a complete understanding of the underpinning biological basis of the two disorders remains fragmented. This narrative review discusses insights into the potential roles of chronic inflammation, impaired hypothalamic-pituitary axis stress response, imbalanced energy metabolism, mitochondrial dysfunction, oxidative stress, and neuroendocrine dysfunction linking physical frailty with cognitive decline. We highlight the importance of easier identification of strategic approaches delaying the progression and onset of physical frailty and cognitive decline as well as preventing disability in the older population.

Inflammatory markers associated with fall recurrence and severity: The Bambuí Cohort Study of Aging

BACKGROUND

The aim of this study was to analyze the association between inflammatory markers and recurrent and severe falls in 1304 community-dwelling older adults from the Bambuí Cohort Study of Aging.

METHODS

Information about falls in the previous 12 months was collected, and classified based on recurrence (two or more falls) and severity (requirement of medical attention). The screened biomarkers included interleukins (IL-1β, IL-6, IL-10, and IL-12, TNF), chemokines (CXCL8, CXCL9, CXCL10, CCL2, and CCL5), and high-sensitive C-reactive protein (hs-PCR). Potential confounders included sociodemographic, behavioral, and health indicators. Associations were evaluated through logistic regression, using odds ratios (OR) and 95% confidence intervals (95% CI), with Stata 13.1.

RESULTS

The prevalence of recurrent and severe falls was 10.7% and 9.0%, respectively. After adjustments, elevated levels of IL-12 (OR: 1.92; 95% CI: 1.09-3.37) and CXCL9 (OR: 1.67; 95% CI: 1.05-2.66) were found to be associated with recurrent falls, while elevated levels of TNF (OR: 1.58; 95% CI: 1.01-2.50), IL-12 (OR: 2.04; 95% CI: 1.13-3.70), CXCL10 (OR: 1.75; 95% CI: 1.04-2.92), and CCL5 (OR: 1.90; 95% CI: 1.18-3.07) were associated with severe falls.

CONCLUSIONS

The results highlight a wide range of biomarkers not yet explored in the literature and suggest that inflammation may be an important component of recurrent and severe falls.

MECHANISMS OF ENDOCRINE DISEASE: Sarcopenia in endocrine and non-endocrine disorders

Objective This paper reviews the main mechanisms, diagnostic criteria, treatment options and available data on sarcopenia in endocrine and non-endocrine disorders. The literature notes the presence of sarcopenia as a comorbid condition or a complication of another clinical situation and not a disease that only affects elderly patients. Method We performed a literature review, focusing on the following: mechanisms related to sarcopenia in elderly patients, and sarcopenia as it presents in the context of chronic and endocrine diseases; diagnostic tools and methods; aspects of sarcopenia and treatment options specific to chronic diseases and endocrine disorders respectively. Results Sarcopenia in chronic and endocrine disorders shares many mechanisms with sarcopenia affecting elderly patients, but certain diseases can have a predominant aspect that leads to sarcopenia. The prevalence of sarcopenia varies, depending on different diagnostic criteria, from around 12 to 60% in chronic illnesses and 15 to 90% in endocrine disorders. The interplay between sarcopenia, chronic diseases and elderly patients requires further study, to clarify the impact of each, in terms of prognosis and mortality. Conclusion Awareness of the presentation of sarcopenia in the context of other diseases and ages (and not just the elderly) is fundamental to ensure that preventive measures can be deployed.

Urinary miRNA-29a-3p levels are associated with metabolic parameters via regulation of IGF1 in patients with metabolic syndrome

Circulating microRNAs (miRNAs or miRs) have been demonstrated to serve as diagnostic and prognostic biomarkers in metabolic syndrome (MetS). The role of urinary miRNAs in MetS diagnosis remains unknown. Here, elevated miR-29a-3p levels were observed in urine samples of patients with MetS compared with control subjects using a microarray analysis (n=4/group) and validation via reverse transcription-quantitative polymerase chain reaction (n=40/group). Associations between urinary miR-29a-3p levels and parameters associated with metabolism, such as adiposity, insulin resistance, lipid profiles and hepatic enzymes were further assessed. Multiple linear regression analyses revealed that urinary miR-29a-3p levels were independently correlated with fasting insulin (β=0.561; P<0.001), high density lipoprotein-cholesterol (β=0.242; P<0.001) and body mass index (β=-0.141; P<0.05). The area under the receiver operating characteristic curve was 0.776 and miR-29a-3p had a diagnostic value for MetS with 68.2% sensitivity and 77.3% specificity. Furthermore, insulin-like growth factor 1 was identified as a target of miR-29a-3p by searching bioinformatics databases and was validated by dual-luciferase reporter and western blot assays. In conclusion, elevated urinary miR-29a-3p levels were positively associated with MetS and demonstrated to have a potential value as biomarkers in the diagnosis of MetS. The findings provided a better understanding of the role of urinary miRNAs in pathogenesis of MetS.

Adult individuals with congenital, untreated, severe isolated growth hormone deficiency have satisfactory muscular function

PURPOSE

While growth hormone (GH) and the insulin-like growth factor type I (IGF-I) are known to exert synergistic actions on muscle anabolism, the consequences of prolonged GH deficiency (GHD) on muscle function have not been well defined. We have previously described a large cohort of subjects with isolated GHD (IGHD) caused by a mutation in the GH-releasing hormone receptor gene, with low serum levels of GH and IGF-I. The aim of this study was to assess muscular function in these IGHD subjects.

METHODS

A total of 31 GH-naïve IGHD (16 males) and 40 control (20 males) subjects, matched by age and degree of daily physical activity, were enrolled. Fat free mass was measured by bioelectrical impedance; muscle strength by dynamometry of handgrip, trunk extension, and knee extension; myoelectric activity and muscle fatigue by fractal dimension; conduction velocity in vastus medialis, rectus femoris, and vastus lateralis muscles by surface electromyography.

RESULTS

The IGHD group showed higher knee extension strength both when corrected for weight and fat free mass, and higher handgrip and trunk extension strength corrected by fat free mass. They also exhibit higher conduction velocity of the muscles vastus medialis, rectus femoris, and vastus lateralis, but lower free fat mass and myoelectric activity of the vastus medialis, rectus femoris and vastus lateralis. There were no differences between the two groups in fractal dimension in all studied muscles.

CONCLUSION

Individuals with untreated IGHD have better muscle strength parameters adjusted for weight and fat free mass than controls. They also exhibit greater peripheral resistance to fatigue, demonstrating satisfactory muscle function.

Elevated serum IL-6 and adiponectin levels are associated with frailty and physical function in Chinese older adults

Purpose

Frailty is associated with adverse health outcomes. Its biological markers are essential to enhance diagnostic ease and would contribute to surveillance of the condition. Considering the involvement of pro-inflammatory and nutritional states in frailty, we aimed to investigate whether inflammatory mediators and adipokines are associated with frailty and their relationship with physical function.

Patients and methods

We recruited 130 older adults (90 nonfrail participants and 40 frail participants, mean age: 72.80±8.61 years) who underwent a comprehensive medical history and frailty assessment. The biochemical indicators (eg, blood urea nitrogen [BUN], high-density lipoprotein [HDL], and hemoglobin [HGB]), insulin pathway (glucose, insulin, and insulin-like growth factor 1 [IGF-1]), circulating inflammatory biomarkers (IL-6, tumor necrosis factor receptor 1, and C-reactive protein), and adipokines (adiponectin, vaspin, and leptin) were compared between the two groups. We further analyzed their correlation with physical function.

Results

Frail older adults showed higher levels of BUN, IL-6, adiponectin, vaspin, and glucose and lower levels of IGF-1, HDL, and HGB compared with nonfrail participants. Serum IL-6 levels were negatively correlated with both grip strength (P=0.03) and gait speed (P=0.04). Levels of circulating adiponectin and leptin were adversely correlated with grip strength (P=0.01) and gait speed (P=0.03), respectively. After adjustment for age and sex, the only markers correlated with physical function were IL-6 (r=−0.180, P=0.044) and adiponectin (r=−0.195, P=0.029).

Conclusion

High levels of IL-6, adiponectin, vaspin, and glucose as well as low levels of IGF-1 were found in frail older adults. Furthermore, IL-6, adiponectin, and leptin levels were negatively correlated with physical function, suggesting that inflammatory mediators and adipokines are biomarkers for frailty and decreased function in older adults.