Sarcopenia-a geriatric pandemic : A narrative review

Predictors of hip fracture in 15 European countries: a longitudinal study of 48,533 geriatric adults using SHARE dataset

We investigated the risk factors for hip fracture in 48,533 European older adults for 8 years from 2013 onward. We identified female gender, age above 80, low handgrip strength, and depression as significant risk factors for hip fracture. Our findings may help identify high-risk populations for hip fractures in pre-clinical settings.

OBJECTIVES

Hip fracture is a major cause of functional disability, mortality, and health costs. However, the identification and characterization of its causative factors remain poor.

METHODS

We investigated demography, handgrip strength (HGS), depression, and multiple age-associated comorbidities for predicting future hip fracture in individuals aged 50 or above from 15 European countries (n = 48,533). All participants were evaluated from 2013 to 2020 using four successive waves of the Survey of Health, Aging, and Retirement in Europe (SHARE).

RESULTS

Altogether, 1130 participants developed hip fractures during the study period. We identified female gender, an advancing age from quinquagenarians onward, and a poor socioeconomic status as critical risk factors for future hip fracture. Having mobility difficulty, a low HGS (< 27 kg in men, < 16 kg in women) and higher scores on Euro-D depression scales were also significant risk factors for hip fracture. Summated scales of hypertension, diabetes mellitus, cancer, Alzheimer's disease, and stroke did not appear as risk factors.

CONCLUSION

Collectively, we report advancing age, female gender, low HGS, and depression as independent risk factors for hip fracture. Our findings are useful in identifying high-risk populations for hip fractures in pre-clinical settings before rigorous evaluation and treatment in clinics.

Iron status and sarcopenia-related traits: a bi-directional Mendelian randomization study

Although serum iron status and sarcopenia are closely linked, the presence of comprehensive evidence to establish a causal relationship between them remains insufficient. The objective of this study is to employ Mendelian randomization techniques to clarify the association between serum iron status and sarcopenia. We conducted a bi-directional Mendelian randomization (MR) analysis to investigate the potential causal relationship between iron status and sarcopenia. MR analyses were performed using inverse variance weighted (IVW), MR-Egger, and weighted median methods. Additionally, sensitivity analyses were conducted to verify the reliability of the causal association results. Then, we harvested a combination of SNPs as an integrated proxy for iron status to perform a MVMR analysis based on IVW MVMR model. UVMR analyses based on IVW method identified causal effect of ferritin on appendicular lean mass (ALM, β = - 0.051, 95% CI - 0.072, - 0.031, p = 7.325 × 10-07). Sensitivity analyses did not detect pleiotropic effects or result fluctuation by outlying SNPs in the effect estimates of four iron status on sarcopenia-related traits. After adjusting for PA, the analysis still revealed that each standard deviation higher genetically predicted ferritin was associated with lower ALM (β = - 0.054, 95% CI - 0.092, - 0.015, p = 0.006). Further, MVMR analyses determined a predominant role of ferritin (β = - 0.068, 95% CI - 0.12, - 0.017, p = 9.658 × 10-03) in the associations of iron status with ALM. Our study revealed a causal association between serum iron status and sarcopenia, with ferritin playing a key role in this relationship. These findings contribute to our understanding of the complex interplay between iron metabolism and muscle health.

Diabetes mellitus, malnutrition, and sarcopenia: The bond is not explained by bioelectrical impedance analysis in older adults

As people age, their risk of diabetes mellitus (DM) and sarcopenia increases due to the decline in muscle mass and strength. Bioelectrical impedance analysis (BIA) is a method used to detect changes in body composition. The primary aim of the study was to determine the distribution of BIA variables among a group of non-DM people and two groups of patients with controlled and uncontrolled DM. The secondary aim was to establish the independent association between BIA-derived data, lipidic assets, and the prevalence of metabolic syndromes with DM. This study included a total of 235 participants who were categorized into three groups based on the presence of diabetes mellitus (DM) and their glycated hemoglobin (HbA1c) levels: non-DM, controlled DM (HbA1c≤7.0%), and uncontrolled DM (HbA1c>7.0%). Waist circumference (p=0.005), bone (p<0.001), muscular (p<0.001), and appendicular skeletal mass (p<0.001) were lower in the non-DM group, while sarcopenic risk (p<0.001), total cholesterol (p<0.001), and LDL (p<0.001), were higher. Grip strength (p<0.001), visceral fat (p=0.01), and phase angle (p=0.04) were significantly lower in non-DM than uncontrolled DM patients, as well as the number of drugs taken (p=0.014). A multivariate analysis highlighted that LDL (coefficient -0.006, p=0.01) was negatively associated, while bone mass (coefficient 0.498, p=0.0042) was positively associated with DM uncontrol. Our study shows that BIA may not be the ideal tool for distinguishing between elderly individuals with and without DM, as it can be affected by numerous covariates, including potential differences in glucometabolic and cardiovascular control.

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.

Muscle Delivery of Mitochondria-Targeted Drugs for the Treatment of Sarcopenia: Rationale and Perspectives

An impairment in mitochondrial homeostasis plays a crucial role in the process of aging and contributes to the incidence of age-related diseases, including sarcopenia, which is defined as an age-dependent loss of muscle mass and strength. Mitochondrial dysfunction exerts a negative impact on several cellular activities, including bioenergetics, metabolism, and apoptosis. In sarcopenia, mitochondria homeostasis is disrupted because of reduced oxidative phosphorylation and ATP generation, the enhanced production of reactive species, and impaired antioxidant defense. This review re-establishes the most recent evidence on mitochondrial defects that are thought to be relevant in the pathogenesis of sarcopenia and that may represent promising therapeutic targets for its prevention/treatment. Furthermore, we describe mechanisms of action and translational potential of promising mitochondria-targeted drug delivery systems, including molecules able to boost the metabolism and bioenergetics, counteract apoptosis, antioxidants to scavenge reactive species and decrease oxidative stress, and target mitophagy. Even though these mitochondria-delivered strategies demonstrate to be promising in preclinical models, their use needs to be promoted for clinical studies. Therefore, there is a compelling demand to further understand the mechanisms modulating mitochondrial homeostasis, to characterize powerful compounds that target muscle mitochondria to prevent sarcopenia in aged people.

[Coronavirus disease 2019 and frailty]

Der Verlauf der Coronavirus disease 2019 (COVID-19) ist individuell sehr unterschiedlich. Menschen höheren Lebensalters mit Komorbiditäten sind gefährdeter, schwer zu erkranken oder zu versterben. Gebrechlichkeit (Frailty) ist ein wesentlicher Risikofaktor. Ein Fünftel der Bevölkerung in Mitteleuropa ist älter als 65 Jahre, 10–15 % davon sind als „frail“ anzusehen. Die Pandemie bringt die Gesundheitssysteme vieler Länder an deren Grenzen. Die Entscheidung, welche Patienten noch intensivmedizinisch behandelt werden, führt zu ethischen Diskussionen. Die Clinical Frailty Scale von Rockwood (CFS; CMAJ 173:489–495, 2005) wird in manchen Ländern eingesetzt, diese Entscheidungen zu unterstützen.

Von COVID-19 betroffene 80-jährige Patienten haben ein fast 3,6faches Sterblichkeitsrisiko, verglichen mit der Altersgruppe von 18 bis 49 Jahren. Das Risiko gebrechlicher Patienten (CFS-Scores 6–9) ist mehr als 3fach höher als von robusten (CFS-Scores 1–3). Ein CFS-Cut-off-Wert ≥ 6 korreliert mit der Mortalität von COVID-19-Patienten über 65 Jahre. Das mittel- und längerfristige Überleben ist auch mit dem Ausmaß von „Frailty“ vor der Erkrankung und weniger mit dem Schweregrad der COVID-19 assoziiert.

Besonders Patienten über 60 Jahre sind gefährdet, bei moderaten und schweren COVID-19-Verläufen rasch Muskelmasse zu verlieren. Patienten auf Intensive Care Units (ICU) verlieren innerhalb von 10 Tagen 20–30 % der Oberschenkelstreckmuskulaturmasse. Das Ausmaß der COVID-19-assoziierten Sarkopenie bestimmt wesentlich den Verlauf der Erkrankung und macht individuelle Rehabilitationsprogrammen erforderlich. Bis zu 50 % der hospitalisierten Patienten benötigen weitere Rehabilitation nach der Entlassung. Aerobes Training mit niedriger Intensität, kombiniert mit Krafttraining, sowie die Sicherstellung einer ausreichenden Energie- und Eiweißzufuhr sind unerlässlich.