Relationships Between Profiles of Physical Activity and Major Mobility Disability in the LIFE Study

Cross-sectional and longitudinal associations between physical activity and intrinsic capacity in healthy older adults from the MAPT study

BACKGROUND

The construct of intrinsic capacity (IC) has been recently developed with the aim of assessing and monitoring life-long individuals' functional trajectories. Physical activity (PA) is recognized for its benefits on health but its associations with IC remain less investigated. We explored the cross-sectional and longitudinal associations of PA with IC in non-demented older adults.

METHODS

Eight hundred and thirty-seven males and females aged 70 years and over, were included in the present work. IC and its domains (mobility, vitality, cognition, psychology and sensory) were assessed over 2 years and converted to a 0-100 scale. Participants were categorized into 5 PA groups (0-29; 30-499; 500-999; 1000-1999; and 2000+ MET-min/week) using questionnaires. The associations between PA and IC variables (all reflected and square-root-transformed) observed over 2 years were examined using mixed-effect linear regressions.

FINDINGS

Over the 2-year follow-up, ordinal PA was associated with higher scores in IC (B = -0.066, SE = 0.015, p < .001) In addition, compared to the inactive group, most of the active groups had a slower decline in IC (B30-499 MET-min/week = -0.196, SE = 0.078; B500-999 MET-min/week = -0.208, SE = 0.076; B1000-1999 MET-min/week = -0.165, SE = 0.073; B2000+MET-min/week = -0.187, SE = 0.074; all p < .05). Subdomain analyses revealed that these associations were driven by mobility, vitality and psychological domain.

INTERPRETATION

This study suggests that PA may help preventing IC decline, especially mobility, vitality, and psychology in older adults.

Multimorbidity Patterns, Leisure Activities, and Cognitive Function: A Population-Based Longitudinal Study

BACKGROUND

There is limited knowledge about the effect of leisure activities on cognitive decline related to different multimorbidity patterns. The study aimed to examine the role of leisure activities in the association between multimorbidity patterns and cognitive function.

METHODS

We conducted a community-based cohort study based on the 2002-2018 Chinese Longitudinal Health Longevity Survey. Multimorbidity patterns were examined by exploratory factor analysis. Multivariable linear and logistic regression models were used to assess the associations between multimorbidity, leisure activities, and cognitive function.

RESULTS

The study included 14 093 older adults. Those with specific multimorbidity patterns had lower Mini-Mental State Examination (MMSE) scores. Compared with individuals with cardiometabolic and sensory patterns who frequently engaged in activities such as housework, garden work, and watching TV/listening to the radio, those who participated in these activities less regularly had lower MMSE scores. Furthermore, a higher frequency change of participation and a greater variety of leisure activities were associated with better cognitive function.

CONCLUSIONS

The older individuals with multimorbidity are associated with lower MMSE scores, while those who participated in more leisure activities had higher cognitive function. Diverse and frequent leisure activities may help delay cognitive decline in Chinese older adults with different multimorbidities.

Multidisciplinary understanding of modifiable physical disability risk factors for health professionals: A scoping review protocol

INTRODUCTION

Physical disability represents a major burden to health and lifespan, particularly as the proportion of older adults within the United States is expected to grow. Prevention efforts for physical disability targets methods and strategies to decrease modifiable risk factors. Potential challenges for health professionals may exist in synthesizing and interpreting this broad spectrum of literature due to the discipline-specific nuance of language used, practice type or specialty, and lack of interdisciplinary resources. This scoping review will map and synthesize the literature across healthcare disciplines to identify modifiable risk factors and the evidence related to their ability to predict physical disability. We will also draw attention to the possibility of modifiable risk factors for physical disability being operationalized as pre-disability in order to strengthen primary and secondary prevention efforts.

METHODS

A planned search strategy using physical disability terminology will be searched in English across MEDLINE, CINAHL, Health Source, PEDro, and REHABDATA by two reviewers in line with our review objectives and inclusion criteria. Eligibility for inclusion include peer-reviewed primary research published in the English language and have established a relationship between a person-level measurable characteristic that is modifiable by changes in lifestyle behaviors and any of the commonly accepted terms used to categorize or describe physical disability.

EXPECTED RESULTS

Presentation of results will be using the PRISMA flowchart, with additional mapping and synthesis of evidence for modifiable risk factors for physical disability to clarify divergent terms used in classifying and measuring these factors and their potential for prediction of physical disability.

EXPECTED CONCLUSION

It is anticipated that this scoping review will identify and highlight a variety of modifiable risk factors for physical disability that may aid primary and secondary prevention efforts for health professionals.

The Symptom Experience of Older Adults with Mobility Difficulties: Qualitative Interviews

Eighteen million older adults have mobility limitations, defined as difficulty walking a quarter of a mile or climbing stairs unassisted. Little is known about how symptom burden impacts mobility difficulty in older adults. Understanding the burden of symptoms responsible for mobility difficulties may be an area for intervention to improve mobility and to prevent adverse outcomes. We conducted 31 semi-structured qualitative interviews (one interview per participant) regarding the symptom burden experience associated with a current mobility difficulty. Thematic analysis revealed symptoms were limiting, were barriers to participation in daily activities, and produced a psychological and emotional burden that negatively impacted quality of life. Older adults employed various strategies to overcome the symptom burden. Participants also believed symptoms were a non-modifiable part of the aging process and at times felt disregarded by healthcare professionals. Future interventions should focus on reducing the symptom burden experience for older adults to improve mobility and prevent adverse outcomes.

Inflammatory, mitochondrial, and senescence-related markers: Underlying biological pathways of muscle aging and new therapeutic targets

The maintenance of functional health is pivotal for achieving independent life in older age. The aged muscle is characterized by ultrastructural changes, including loss of type I and type II myofibers and a greater proportion of cytochrome c oxidase deficient and succinate dehydrogenase positive fibers. Both intrinsic (e.g., altered proteostasis, DNA damage, and mitochondrial dysfunction) and extrinsic factors (e.g., denervation, altered metabolic regulation, declines in satellite cells, and inflammation) contribute to muscle aging. Being a hub for several cellular activities, mitochondria are key to myocyte viability and mitochondrial dysfunction has been implicated in age-associated physical decline. The maintenance of functional organelles via mitochondrial quality control (MQC) processes is, therefore, crucial to skeletal myofiber viability and organismal health. The autophagy-lysosome pathway has emerged as a critical step of MQC in muscle by disposing organelles and proteins via their tagging for autophagosome incorporation and delivery to the lysosome for clearance. This pathway was found to be altered in muscle of physically inactive older adults. A relationship between this pathway and muscle tissue composition of the lower extremities as well as physical performance was also identified. Therefore, integrating muscle structure and myocyte quality control measures in the evaluation of muscle health may be a promising strategy for devising interventions fostering muscle health.

Sarcopenia and Cognitive Decline in Older Adults: Targeting the Muscle-Brain Axis

Declines in physical performance and cognition are commonly observed in older adults. The geroscience paradigm posits that a set of processes and pathways shared among age-associated conditions may also serve as a molecular explanation for the complex pathophysiology of physical frailty, sarcopenia, and cognitive decline. Mitochondrial dysfunction, inflammation, metabolic alterations, declines in cellular stemness, and altered intracellular signaling have been observed in muscle aging. Neurological factors have also been included among the determinants of sarcopenia. Neuromuscular junctions (NMJs) are synapses bridging nervous and skeletal muscle systems with a relevant role in age-related musculoskeletal derangement. Patterns of circulating metabolic and neurotrophic factors have been associated with physical frailty and sarcopenia. These factors are mostly related to disarrangements in protein-to-energy conversion as well as reduced calorie and protein intake to sustain muscle mass. A link between sarcopenia and cognitive decline in older adults has also been described with a possible role for muscle-derived mediators (i.e., myokines) in mediating muscle-brain crosstalk. Herein, we discuss the main molecular mechanisms and factors involved in the muscle-brain axis and their possible implication in cognitive decline in older adults. An overview of current behavioral strategies that allegedly act on the muscle-brain axis is also provided.

Physical Activity Programming for Older Adults in Assisted Living: Residents' Perspectives

Decreasing sedentary behavior and increasing light physical activity could promote the maintenance of functional abilities for older adults in assisted living (AL). The purpose of this qualitative study was to gather residents' recommendations about a proposed self-efficacy enhancing intervention to replace sedentary behavior with light physical activity. We interviewed 20 residents (mean age 83.1; 60% women). Topics included their current activities and thoughts about physical activity. We presented the intervention and asked questions to inform its modification. Data were analyzed with content and thematic analysis. Specific recommendations included shorter one-hour sessions and framing the intervention as increasing light physical activity rather than decreasing sedentary behavior. The thematic analysis identified multiple factors that could influence intervention implementation, including motivation to be active, safety concerns, ageist attitudes about physical activity, varying abilities of residents, social influences, and limited opportunities for physical activity. These results will inform physical activity intervention implementation for AL residents.

Relationship between Mitochondrial Quality Control Markers, Lower Extremity Tissue Composition, and Physical Performance in Physically Inactive Older Adults

Altered mitochondrial quality and function in muscle may be involved in age-related physical function decline. The role played by the autophagy-lysosome system, a major component of mitochondrial quality control (MQC), is incompletely understood. This study was undertaken to obtain initial indications on the relationship between autophagy, mitophagy, and lysosomal markers in muscle and measures of physical performance and lower extremity tissue composition in young and older adults. Twenty-three participants were enrolled, nine young (mean age: 24.3 ± 4.3 years) and 14 older adults (mean age: 77.9 ± 6.3 years). Lower extremity tissue composition was quantified volumetrically by magnetic resonance imaging and a tissue composition index was calculated as the ratio between muscle and intermuscular adipose tissue volume. Physical performance in older participants was assessed via the Short Physical Performance Battery (SPPB). Protein levels of the autophagy marker p62, the mitophagy mediator BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), the lysosomal markers transcription factor EB, vacuolar-type ATPase, and lysosomal-associated membrane protein 1 were measured by Western immunoblotting in vastus lateralis muscle biopsies. Older adults had smaller muscle volume and lower tissue composition index than young participants. The protein content of p62 and BNIP3 was higher in older adults. A negative correlation was detected between p62 and BNIP3 and the tissue composition index. p62 and BNIP3 were also related to the performance on the 5-time sit-to-stand test of the SPPB. Our results suggest that an altered expression of markers of the autophagy/mitophagy-lysosomal system is related to deterioration of lower extremity tissue composition and muscle dysfunction. Additional studies are needed to clarify the role of defective MQC in human muscle aging and identify novel biological targets for drug development.

Facilitators and barriers to real-life mobility in community-dwelling older adults: a narrative review of accelerometry- and global positioning system-based studies

Real-life mobility, also called "enacted" mobility, characterizes an individual's activity and participation in the community. Real-life mobility may be facilitated or hindered by a variety of factors, such as physical abilities, cognitive function, psychosocial aspects, and external environment characteristics. Advances in technology have allowed for objective quantification of real-life mobility using wearable sensors, specifically, accelerometry and global positioning systems (GPSs). In this review article, first, we summarize the common mobility measures extracted from accelerometry and GPS. Second, we summarize studies assessing the associations of facilitators and barriers influencing mobility of community-dwelling older adults with mobility measures from sensor technology. We found the most used accelerometry measures focus on the duration and intensity of activity in daily life. Gait quality measures, e.g., cadence, variability, and symmetry, are not usually included. GPS has been used to investigate mobility behavior, such as spatial and temporal measures of path traveled, location nodes traversed, and mode of transportation. Factors of note that facilitate/hinder community mobility were cognition and psychosocial influences. Fewer studies have included the influence of external environments, such as sidewalk quality, and socio-economic status in defining enacted mobility. Increasing our understanding of the facilitators and barriers to enacted mobility can inform wearable technology-enabled interventions targeted at delaying mobility-related disability and improving participation of older adults in the community.

Physical activity in older adults with metastatic gastrointestinal cancer: a pilot and feasibility study

Objectives

This study determined the feasibility of delivering a 12-week structured physical activity programme during chemotherapy to older adults recently diagnosed with metastatic gastrointestinal (GI) cancer.

Methods

This study used a single-cohort design. Older adults (aged ≥65 years) diagnosed with metastatic oesophageal, gastric, pancreatic or colorectal cancer who planned to initiate chemotherapy were enrolled. The physical activity programme included a combination of aerobic, flexibility, strength and balance modalities delivered by a certified cancer exercise trainer during chemotherapy infusion appointments, then translated and sustained at home by participants. The co-primary endpoints included: (1) accrual of 20 participants in 12 months and (2) physical activity adherence of ≥50%.

Results

Between March and October 2018, 29 participants were screened, and 20 were enrolled within 12 months (recruitment rate: 69% (90% CI: 55% to 83%); p<0.001), meeting the first co-primary endpoint. The median age of participants was 73.3 years (IQR: 69.3-77.2). At week 12, 67% (90% CI: 48% to 85%) of participants adhered to ≥50% of the prescribed physical activity (p=0.079 (statistically significant)), meeting the second co-primary endpoint. From baseline to week 12, accelerometer-measured light-intensity and moderate-intensity to vigorous-intensity physical activity increased by 307.4 (95% CI: 152.6 to 462.2; p<0.001) and 25.0 min per week (95% CI: 9.9 to 40.1; p=0.001), respectively. There were no serious or unexpected adverse events. The median overall survival was 16.2 months (8.4-22.4).

Conclusion

These results establish the feasibility of a larger scale randomised controlled trial that enrols older adults with metastatic GI cancer and delivers a structured physical activity programme during chemotherapy.

Trial registration number

NCT03331406.

Intervening on physical activity and sedentary behavior in older adults

Participating in sufficient levels of physical activity is important for sustaining health and quality of life across the age span. The United States Physical Activity Guidelines recommend individuals of all ages "move more, more often" by frequently engaging in aerobic activity while avoiding prolonged bouts of sitting. This is indicative of a slow shift in focus in the study of active aging that has occurred in the last two decades. Historically, researchers interested in the influence of physical activity on older adults' health and quality of life focused on discrete sustained bouts of intense activity (i.e., structured exercise). More recently the widespread usage of accelerometers contributed to a large body of evidence demonstrating that long periods spent sedentary were associated with a host of negative health outcomes ranging from poorer cardiometabolic health to poorer physical functioning and elevated risk of death. These findings often persisted when controlling for time spent in higher-intensity physical activity, spurring separate fields of intervention research concerned with promoting exercise or reducing sedentary time. Novel data emerging in recent years on the importance of an individual's overall activity profile (i.e., amount and patterning of light and moderate-to-vigorous activity) has driven yet another shift in focus toward interventions focused explicitly on movement profiles. In this narrative review, we discuss the evolution of thought regarding older adults' physical activity behaviors. We highlight successes and challenges in first promoting structured and prolonged exercise, later in targeting sedentary behavior, and most recently in attempting to intervene on activity profiles. We end our review by highlighting current gaps in research and important future directions.

Sustained physical activity in peripheral artery disease: Associations with disease severity, functional performance, health-related quality of life, and subsequent serious adverse events in the LITE randomized clinical trial

This study investigated cross-sectional associations of peripheral artery disease (PAD) severity (defined by the ankle-brachial index (ABI)) and amounts of daily sustained physical activity (PA) (defined as > 100 activity counts per minute lasting 5 consecutive minutes or more). This study also investigated associations of amounts of daily sustained PA with 6-minute walk (6MW) distance and the Short Form-36 physical functioning domain (SF-36 PF) score in cross-sectional analyses and with serious adverse events (SAEs) in longitudinal analyses of people with PAD. PA was measured continuously for 10 days using a tri-axial accelerometer at baseline in 277 participants with PAD randomized to the LITE clinical trial. In regression analyses, each 0.15 lower ABI value was associated with a 5.67% decrease in the number of daily bouts of sustained PA (95% CI: 3.85-6.54; p < 0.001). Every additional bout of sustained PA per day was associated with a 4.56-meter greater 6MW distance (95% CI: 2.67-6.46; p < 0.0001), and a 0.81-point improvement in SF-36 PF score (95% CI: 0.34-1.28; p < 0.001). Participants with values of daily bouts of sustained PA below the median had higher rates of SAEs during follow-up, compared to participants above the median (41% vs 24%; p = 0.002). In conclusion, among participants with PAD, lower ABI values were associated with fewer bouts of daily sustained PA. A greater number of bouts of daily sustained PA were associated with better 6MW performance and SF-36 PF score, and, in longitudinal analyses, lower rates of SAEs. Clinicaltrials.gov ID: NCT02538900.

Physical activity scaled to preferred walking speed as a predictor of walking difficulty in older adults: a 2-year follow-up

Background

The usual accelerometry-based measures of physical activity (PA) are dependent on physical performance. We investigated the associations between PA relative to walking performance and the prevalence and incidence of early and advanced walking difficulties compared to generally used measures of PA.

Methods

Perceived walking difficulty was evaluated in 994 community-dwelling participants at baseline (age 75, 80, or 85 years) and 2 years later over 2 km (early difficulty) and 500 m (advanced difficulty). We used a thigh-mounted accelerometer to assess moderate-to-vigorous PA, daily mean acceleration, and relative PA as movement beyond the intensity of preferred walking speed in a 6-minute walking test (PA_rel). Self-reported PA was assessed using questionnaires.

Results

The prevalence and incidence were 36.2% and 18.9% for early and 22.4% and 14.9% for advanced walking difficulty, respectively. PA_rel was lower in participants with prevalent (mean 42 [SD 45] vs 69 [91] min/week, p < .001) but not incident early walking difficulty (53 [75] vs 72 [96] min/week, p = .15) compared to those without difficulty. The associations between absolute measures of PA and incident walking difficulty were attenuated when adjusted for preferred walking speed.

Conclusions

The variation in habitual PA may not explain the differences in the development of new walking difficulty. Differences in physical performance explain a meaningful part of the association of PA with incident walking difficulty. Scaling of accelerometry to preferred walking speed demonstrated independence on physical performance and warrants future study as a promising indicator of PA in observational studies among older adults.

Treat-to-target in axial spondyloarthritis - what about physical function and activity?

In patients with axial spondyloarthritis (axSpA), pain, functional and structural impairments, reduced mobility and potential deformity of the axial skeleton are the most prominent health concerns. Limitations in physical function and spinal mobility are caused by both inflammation and structural damage, and therefore restrictions to physical function must be monitored throughout a patient's life. Consequently, the assessment of physical function is recommended as a key domain in the Assessment of Spondyloarthritis International Society-OMERACT Core Outcome Set. However, in comparison with disease activity, physical function seems to be a relatively neglected target of intervention in patients with axSpA, even though physical function is a major contributor to costs and disability in this disease. This Review aims to reacquaint rheumatologists with the targets for physical function, physical activity and performance by giving guidance on determinants of physical function and how physical function can be examined in patients with axSpA.

Health Promoting Behaviors, Health Needs and Associated Factors among Older Adults in Jordan: A Cross-Sectional Study

BACKGROUND

Several factors affect older adults' engagement in HPBs. This study aimed to examine HPBs, health needs, and associated factors among older adults in Jordan.

METHODS

A cross-sectional study was conducted on 220 older adults at one governmental and one university hospital, which were selected using convenience sampling for geographical closeness to the researchers. All older adults with no cognitive or communication problems who attended the outpatient clinics of the two hospitals from December 2018 to April 2019 were included in the study. This time period was chosen based on the convenience of the participants and researchers. Data were collected by An Arabic version of the Health-Promoting Lifestyle Profile (HPLP) and a demographic questionnaire. The Statistical Package for Social Science (SPSS) 25.0 software was used for the descriptive and inferential analysis of the study data. The level of significance was set at P<0.05.

RESULTS

The mean score of the total HPLP was 125.33±19.09. The marital status and educational level of the participants were associated with the total HPLP (P<0.001) in all its dimensions, except for the dimension of interpersonal relations. Participants with chronic diseases had lower scores than those without diseases for the total HPLP (P<0.001) in all the six dimensions. Family income was positively correlated with the dimensions of nutrition (P=0.007) and exercise (P=0.002).

CONCLUSION

Despite the good overall mean score of older adults for total HPLP and some of its subscales, their levels of exercise and physical activity need to be promoted. The scores of older adults were related to various demographic and clinical factors.

The efficacy of exergaming in people with major neurocognitive disorder residing in long-term care facilities: a pilot randomized controlled trial

BACKGROUND

It is currently unknown whether exergaming is efficacious in people with major neurocognitive disorder (MNCD) residing in long-term care facilities. This pilot randomized controlled trial (RCT) explored the efficacy of a stepping exergame program on gait speed, balance, mobility, reaction time, cognitive and neuropsychiatric outcomes, quality of life, and daily life functioning in people with MNCD residing in long-term care facilities.

METHODS

Participants were randomly assigned to 8 weeks, three times weekly, 15 min of exergaming versus watching preferred music videos. The exergame device consisted of a pressure-sensitive step training platform on which participants performed stepping movements to play the games. The device automatically adapted the training level to the participants' capabilities. The Short Physical Performance Battery (SPPB), step reaction time test (SRTT), Montréal Cognitive Assessment (MoCA), Neuropsychiatric Inventory (NPI), Cornell Scale for Depression in Dementia (CSDD), Dementia Quality of Life (DQoL), and Katz Activities of Daily Living (Katz ADL) were assessed at baseline and post-intervention. A Quade's non-parametric ANCOVA controlling for baseline values with post hoc Bonferroni correction (p < 0.00625) was used to analyze pre- and post-differences between the groups. Partial eta-squared (η²p) effect sizes were calculated.

RESULTS

Forty-five of 55 randomized inpatients with mild to moderate MNCD (Mini-Mental State Examination score = 17.2 ± 4.5; aged 70-91; 35 women) completed the study. The exergame group (n = 23) demonstrated improvements in gait speed (p < 0.001, η²_p = 0.41), total SPPB (p < 0.001, η²_p = 0.64), SRTT (p<0.001, η²_p = 0.51), MoCA (p<0.001, η²_p = 0.38), and reductions in CSDD (p<0.001, η²_p = 0.43) compared to the control group (n = 22). There were no differences in NPI (p = 0.165, η²_p = 0.05), DQoL (p = 0.012, η²_p = 0.16), and ADL (p = 0.008, η²_p = 0.16) post-intervention scores between the experimental and control group, albeit DQol and ADL measures showed large effect sizes in the exergame group. The mean attendance rate was 82.9% in the exergame group and 73.7% in the music control group. There were no study-related adverse events reported by the participants, nor observed by the research team.

CONCLUSIONS

The findings of this pilot RCT suggest that an individually adapted exergame training improves lower extremity functioning, cognitive functioning and step reaction time and symptoms of depression in inpatients with MNCD residing in long-term care facilities.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04436302.

Associations Between Accelerometer-Based Free-Living Walking and Self-Reported Walking Capability Among Community-Dwelling Older People

The authors examined whether accelerometer-based free-living walking differs between those reporting walking modifications or perceiving walking difficulty versus those with no difficulty. Community-dwelling 75-, 80-, or 85-year-old people (N = 479) wore accelerometers continuously for 3-7 days, and reported whether they perceived no difficulties, used walking modifications, or perceived difficulties walking 2 km. Daily walking minutes, walking bouts, walking bout intensity and duration, and activity fragmentation were calculated from accelerometer recordings, and cut points for increased risk for perceiving walking difficulties were calculated using receiver operating characteristic analysis. The authors' analyses showed that accumulating ≤83.1 daily walking minutes and walking bouts duration ≤47.8 s increased the likelihood of reporting walking modifications and difficulties. Accumulating walking bouts ≤99.4 per day, having walking bouts ≤0.119 g intensity, and ≥0.257 active to sedentary transition probability fragmented activity pattern were associated only with perceiving walking difficulties. The findings suggest that older people's accelerometer-based free-living walking reflects their self-reported walking capability.

Altered Expression of Mitoferrin and Frataxin, Larger Labile Iron Pool and Greater Mitochondrial DNA Damage in the Skeletal Muscle of Older Adults

Mitochondrial dysfunction and iron (Fe) dyshomeostasis are invoked among the mechanisms contributing to muscle aging, possibly via a detrimental mitochondrial-iron feed-forward loop. We quantified the labile Fe pool, Fe isotopes, and the expression of mitochondrial Fe handling proteins in muscle biopsies obtained from young and older adults. The expression of key proteins of mitochondrial quality control (MQC) and the abundance of the mitochondrial DNA common deletion (mtDNA4977) were also assessed. An inverse association was found between total Fe and the heavier Fe isotope (56Fe), indicating an increase in labile Fe abundance in cells with greater Fe content. The highest levels of labile Fe were detected in old participants with a Short Physical Performance Battery (SPPB) score ≤ 7 (low-functioning, LF). Protein levels of mitoferrin and frataxin were, respectively, higher and lower in the LF group relative to young participants and older adults with SPPB scores ≥ 11 (high-functioning, HF). The mtDNA4977 relative abundance was greater in old than in young participants, regardless of SPPB category. Higher protein levels of Pink1 were detected in LF participants compared with young and HF groups. Finally, the ratio between lipidated and non-lipidated microtubule-associated protein 1A/1B-light chain 3 (i.e., LC3B II/I), as well as p62 protein expression was lower in old participants regardless of SPPB scores. Our findings indicate that cellular and mitochondrial Fe homeostasis is perturbed in the aged muscle (especially in LF older adults), as reflected by altered levels of mitoferrin and frataxin, which, together with MQC derangements, might contribute to loss of mtDNA stability.