The research, led by Baptiste Perthuy and Leslie M. Decker of the COMETE laboratory at Université de Caen Normandie, together with colleagues including Nick Stergiou of the University of Nebraska at Omaha and Fabien Cignetti of the Grenoble Institute of Neurosciences, took an unusual approach. Rather than comparing group averages, the team built a normative model of healthy walking and then measured how far each individual deviated from it, domain by domain. Ninety-seven adults aged 55 and over completed two treadmill walking bouts of three minutes and thirty seconds at their preferred speed. The participants fell into three groups: twenty older adults with MCR, twenty healthy older adults with slow gait who were matched to the MCR group on demographics and walked at comparably slow speeds, and fifty-seven healthy older adults who served as the reference population.

The methodological core of the study lies in how walking was decomposed. The researchers organized a battery of linear spatiotemporal measures and nonlinear variables derived from trunk acceleration into ten functional gait domains. These were conceptually grouped into three tiers: gait pattern, covering pace, rhythm, gait phases, postural control, and symmetry; fluctuation amplitude, essentially step-to-step variability; and the temporal structure of those fluctuations, which includes regulation, signal complexity, divergence of movement trajectories, and attractor complexity. This domain-based framework reflects a growing consensus in the biomechanics literature that gait is not a single quantity but a bundle of partly independent control processes, each with its own neural substrates.

To quantify deviation, the team trained a Gaussian mixture model on data from the healthy older adults. A Gaussian mixture model is a probabilistic machine learning technique that fits a set of overlapping bell-shaped distributions to data, effectively learning the shape of normal variation in each gait domain. Once trained, the model defines a normative reference space, and any new individual can be assigned an anomaly score that expresses how improbable their gait profile is relative to that healthy distribution. This approach, borrowed from normative modeling in computational psychiatry, sidesteps a chronic weakness of case-control studies: it does not assume that a clinical group is merely shifted in the average, but instead maps each person’s position within or outside the healthy manifold.

The results split cleanly into two layers. Both the MCR group and the healthy slow walkers showed elevated deviations in gait pattern domains, specifically pace and phases, which is exactly what one would expect given their slower walking speed. In other words, the coarse, speed-related signature of gait does not distinguish MCR from ordinary age-related slowing. That finding alone is a pointed critique of gait speed as a stand-alone clinical marker: two people can walk at the same slow tempo for entirely different reasons, and a stopwatch cannot tell them apart.

The second layer is where the study becomes striking. Only the MCR group showed additional deviations in the domains related to fluctuation amplitude and temporal structure. Their walking exhibited increased step-to-step variability, and their trunk acceleration fluctuations were more divergent, more predictable, and less complex than those of healthy walkers. Each of those adjectives carries technical weight. Greater divergence of movement trajectories, typically quantified through Lyapunov exponents, indicates that small perturbations during walking grow faster over time, a hallmark of reduced local dynamic stability. Greater predictability and reduced complexity, often measured with entropy-based statistics, suggest that the gait pattern has become more rigid and stereotyped, losing the adaptive variability that characterizes healthy neuromotor control.

These nonlinear findings resonate with a theoretical framework that Stergiou and Decker helped develop more than a decade ago, which proposes that healthy movement occupies an optimal zone of variability, and that pathology pushes movement either toward excessive randomness or excessive regularity. The MCR signature observed here, with both elevated variability and reduced complexity, fits the picture of a neuromotor system that has lost fine-grained regulation. It also aligns with neuroimaging work linking MCR to cortical atrophy and white matter hyperintensities, since the brain networks that support executive function and attention are deeply involved in orchestrating the moment-to-moment regulation of gait fluctuations.

The clinical implications are considerable. Because the anomaly scores are computed per domain and per individual, they could function as personalized, interpretable digital biomarkers. A clinician could, in principle, see not just that a patient’s gait is abnormal, but which specific control processes are deviating from the healthy reference and by how much. That granularity matters for early detection, since the MCR signature identified here was visible even in a modest sample of twenty affected individuals, and it matters for monitoring, because domain-specific scores could in future studies track whether an intervention is restoring healthy gait dynamics rather than merely speeding someone up. The treadmill protocol itself, two short bouts at preferred speed with trunk-worn accelerometry, is simple enough to imagine translating into routine geriatric assessment.

Important caveats remain. The study is cross-sectional, so it demonstrates association rather than prediction; it cannot yet say whether the multidimensional signature precedes cognitive decline or emerges alongside it. The MCR group is small, and treadmill walking, while well controlled, differs in known ways from overground walking. The authors note that data are available from the corresponding author upon reasonable request, and the study, conducted within the PRESAGE project in Normandy with support from European and regional funders, was designed with the kind of immersive and instrumented facilities that allow unusually rich movement recording. Whether the anomaly-detection framework generalizes to community-based cohorts and to overground or free-living walking will be the decisive test.

Even so, the study marks a conceptual shift in how the field might think about the motor face of cognitive risk. Gait speed tells you that something may be wrong; the temporal architecture of movement fluctuations begins to tell you what. If subsequent longitudinal work confirms that the complexity and stability domains identified here predict conversion to major neurocognitive disorders ahead of conventional markers, the humble act of walking a few minutes on a treadmill, read through the right mathematical lens, could become one of the most accessible windows into the aging brain that medicine currently possesses.

Subject of Research: Multidimensional gait analysis and anomaly detection for identifying motoric cognitive risk syndrome in older adults

Article Title: Beyond gait speed: a multidimensional motor signature of motoric cognitive risk syndrome identified through domain-specific anomaly detection

Article References: Perthuy, B., Vinzant, H., Brifault, C., Cabibel, V., Laillier, R., Sultan, A., Denise, P., Lefèvre, N., Dalibot, A., Stergiou, N., Cignetti, F., & Decker, L. M. (2026). Beyond gait speed: a multidimensional motor signature of motoric cognitive risk syndrome identified through domain-specific anomaly detection. GeroScience. https://doi.org/10.1007/s11357-026-02493-4

Image Credits: AI Generated

DOI: 10.1007/s11357-026-02493-4

Keywords: motoric cognitive risk syndrome, gait analysis, gait speed, gait variability, nonlinear dynamics, anomaly detection, Gaussian mixture model, digital biomarkers, dementia risk, older adults, GeroScience, treadmill walking

The stakes are enormous. Dementia currently affects roughly 50 million people worldwide, and projections suggest that number could nearly triple by 2050, reaching around 150 million. Alzheimer’s disease and vascular dementia account for the vast majority of cases, and in 30 to 40 percent of patients the two pathologies coexist. While new pharmacological therapies for early Alzheimer’s disease have generated excitement, they remain insufficient to slow the epidemic at a population level. The 2024 Lancet Commission on dementia prevention estimated that up to 45 percent of cases could be prevented by addressing 14 modifiable risk factors spanning early life, midlife and late life—among them hypertension, obesity, physical inactivity and social isolation.

Executive function is among the cognitive domains most sensitive to aging. Early losses in planning, inhibition and cognitive flexibility interfere with instrumental activities of daily living, reduce social participation and elevate dementia risk. Physical inactivity feeds this process through obesity, diabetes, dyslipidaemia and hypertension, but it also appears to act more directly: activity levels are consistently linked to executive performance over time. Objective markers such as gait speed, handgrip strength and leg muscle power integrate neuromuscular capacity, cardiometabolic health and central motor control into a single measurable phenotype, and previous research has tied them to independence, disability and dementia onset years before diagnosis.

What no study had done before, however, was test whether physical performance moderates—that is, changes the strength of—the relationship between age and executive function, rather than merely correlating with it. The research team, working with community-dwelling adults aged 60 to 85 recruited through town halls, mailings and media campaigns in Donostia/San Sebastián, enrolled participants with a high cardiovascular dementia risk score and subtle cognitive weaknesses, but without dementia or loss of functional independence. Only 6.8 percent of the sample met criteria for mild cognitive impairment, making the cohort a window into the preclinical stage of decline.

Executive function was measured with two well-validated instruments. The Trail Making Test asks participants to connect numbered circles and then to alternate between numbers and letters; subtracting the time for the simpler part from the harder part isolates the executive demands of task-switching. The Stroop test, in which people must name the ink colour of mismatched colour words, probes inhibitory control independently of literacy. Physical performance was assessed with a six-metre walk at usual pace, a handheld dynamometer measuring maximal grip force, and a leg press fitted with a linear encoder that captured peak lower-limb power during explosive contractions. Brain scans graded white matter hyperintensities—the hallmark of cerebral small vessel disease—on the Fazekas scale.

The results were striking in their consistency. After adjusting for sex, socioeconomic status, depressive symptoms, body mass index, anxiety, diabetes, hypertension, dyslipidaemia and smoking, all six age-by-performance interactions remained significant after false-discovery-rate correction. Each year of age added roughly 2.6 to 3.0 seconds to the Trail Making difference score and about half a second to Stroop interference, but higher physical performance blunted these penalties. Standardized interaction coefficients were modest yet reliable across both cognitive tests, and the pattern held whether the outcome was task-switching speed or inhibitory control.

The most novel contribution came from Johnson–Neyman analyses, which pinpoint the exact values of a moderator at which an effect disappears. For the whole sample, the damaging association between age and executive function became statistically undetectable above a gait speed of 1.83 metres per second, a handgrip strength of 48.8 kilograms, or a peak leg power of 438 watts on the Trail Making measure—and above 1.68 metres per second, 43.9 kilograms and 366 watts on the Stroop measure. These thresholds sit at the extreme upper end of the performance distribution: only about 1 to 16 percent of participants reached them, depending on the marker and test. The authors caution that these are sample-specific regions of significance, not clinical cutoffs ready for the doctor’s office.

Sex shaped the picture in intriguing ways. For the Trail Making test, the moderating effect of gait speed was confined to men, and a formal three-way interaction confirmed the specificity: among males, the age-related penalty on executive performance vanished above a gait speed of 1.59 metres per second, a level achieved by 14 percent of the men. For the Stroop task, gait speed moderated the association within the female stratum, but the corresponding three-way interaction was not significant, so the researchers urge against over-reading this as a true sex difference. Notably, when grip strength and leg power were re-expressed relative to body size, the moderation effects attenuated to nonsignificance, suggesting that absolute neuromuscular capacity—not strength adjusted for mass—drove the buffering effect.

Several sensitivity checks strengthened the findings. Excluding participants with mild cognitive impairment left most associations intact, indicating the pattern was not simply an artifact of incipient decline, though the gait effect on task-switching did weaken—hinting that gait speed may be an especially sensitive marker of executive problems in people already showing cognitive impairment. Adjusting for sleep quality or standing height changed little. White matter hyperintensity burden, present at moderate-to-high levels in nearly 29 percent of participants, did not independently predict executive function after full covariate adjustment, though the authors attribute this partly to the coarse visual Fazekas rating and the reduced MRI subsample of 774 people, and they stress this does not overturn the well-established links between small vessel disease and cognition.

Beyond the physical findings, socioeconomic status emerged as the second most powerful independent predictor of executive performance after age itself, with each step up the index corresponding to roughly 11 to 15 seconds of faster task-switching across both sexes—a vivid demonstration of cognitive reserve built through education, occupational complexity and access to healthier lifestyles. The study’s cross-sectional design cannot establish causality, and unmeasured factors such as medication use, habitual activity and APOE genotype may still confound the results. Yet the work offers a reproducible analytic template for the World Wide FINGERS network of multidomain prevention trials and raises a provocative possibility: that exceptionally high neuromuscular performance represents a functional reserve capable of buffering brain aging, complementing vascular-risk control. Whether those extreme performance levels can be reached through exercise interventions begun later in life—and whether doing so translates into real cognitive protection—remains the critical question for longitudinal research now underway.

Subject of Research: The moderating role of physical performance in the relationship between age and executive function in older adults at elevated risk of dementia

Article Title: Physical Performance Moderates the Association Between Age and Executive Function in Older Adults at Elevated Risk of Dementia: Cross‐Sectional Analysis From the CITA GO‐ON Trial

Article References: Reparaz‐Escudero, I., Izquierdo, M., Ecay‐Torres, M., Altuna, M., López, C., Estanga, A., García‐Sebastián, M., de Arriba, M., Ros, N., Saldias, J., Limousin, M., Martínez‐Lage, P., & Sáez de Asteasu, M. L. (2026). Physical Performance Moderates the Association Between Age and Executive Function in Older Adults at Elevated Risk of Dementia: Cross‐Sectional Analysis From the CITA GO‐ON Trial. Journal of Cachexia, Sarcopenia and Muscle, 17(5), Article e70396. https://doi.org/10.1002/jcsm.70396

Image Credits: AI Generated

DOI: 10.1002/jcsm.70396

Keywords: dementia, executive function, gait speed, handgrip strength, muscle power, aging, cognitive reserve, white matter hyperintensities, CITA GO-ON trial, sarcopenia, physical performance, dementia prevention

The trial, known as APPAHOCA-2, is described in BMC Geriatrics by Heidi Solem-Laviec of the Centre François Baclesse in Caen and her colleagues across two French centers. It is designed as a prospective, multicenter, open-label phase II study that will enroll 60 patients aged 65 and older who are scheduled for elective major cancer surgery or operations expected to carry high morbidity. Rather than waiting until complications appear, the investigators intend to measure whether daily supervised treadmill sessions can preserve or restore what geriatricians call functional fitness, using a well-established clinical yardstick: the six-minute walk test, or 6MWT. The distance a patient can cover in six minutes reflects the integrated performance of the heart, lungs, muscles, and nervous system, which is precisely why it has become a favored endpoint in studies of surgical recovery.

The logic of the design rests on a careful baseline. Before any operation takes place, each enrolled patient completes a comprehensive geriatric assessment during the month preceding surgery, and that visit includes a 6MWT measurement that captures the patient’s preoperative walking capacity. This pre-surgical value then becomes the reference point against which recovery is judged. The main endpoint of the trial is the proportion of patients who, at the time of discharge from the surgical ward, have regained their preoperative functional fitness as measured by the same test. In other words, the study does not ask whether patients simply improved over their hospital stay, but whether the intervention allowed them to climb back to their own personal starting line before going home.

The intervention itself is deliberately pragmatic. Unless a medical contraindication exists, patients in the trial will be offered one to two walking sessions per day on a treadmill, beginning the day after their operation. Each session is supervised by an Adapted Physical Activity Specialist, a professional trained to calibrate exercise intensity to fragile, recently operated patients, and the target duration ranges from six to thirty minutes. That flexibility matters. Early after abdominal, thoracic, or head and neck cancer surgery, a patient may manage only a few cautious minutes, while later in the admission the same person may tolerate a half hour of steady walking. The protocol’s designers have built that natural trajectory into the intervention rather than imposing a rigid dose that many frail patients could not achieve.

The scientific rationale comes in part from an earlier pilot study conducted by the same group, which showed that supervised treadmill walking in older cancer inpatients was feasible and could improve gait speed, with one important caveat: the benefit appeared in patients who were not malnourished. That finding highlights a biological reality that geriatric oncologists know well. Muscle recovery after surgery depends on an adequate supply of protein and energy, and in a patient whose nutrition is compromised, exercise can become a drain rather than a stimulus. The APPAHOCA-2 protocol therefore treats nutritional status as a critical variable, assessing it alongside sarcopenia, the age-related loss of skeletal muscle mass and strength that both cancer and major surgery can accelerate.

What makes the trial unusually comprehensive is the breadth of data it will collect. Assessments are scheduled at three points: before surgery, at hospital discharge, and at routine surgical follow-up visits 30 and 90 days after the operation. At each of these time points, the researchers will record levels of anxiety and depression, concerns about falling, cognitive function, nutritional and sarcopenia status, sleep complaints and changes in sleep-wake patterns, daytime activity, physical performance measures, and results from blood examinations. This multidimensional approach reflects a growing recognition in geriatric medicine that physical recovery cannot be separated from mental health, cognition, sleep, and metabolic state. A patient who walks farther but falls asleep poorly or becomes anxious about falling may not actually function better at home.

The hospital environment itself is a central character in this story. Clinical guidelines on postoperative rehabilitation have long advocated early mobilization, yet hospital wards are rarely designed to make walking safe and appealing for frail older adults. Corridors are busy, floors may be slippery, IV poles and monitoring equipment tether patients to their rooms, and nursing workloads leave little time for escorted walks. A walking treadmill, paradoxically, can offer a more controlled and secure environment than the ward corridor itself: handrails provide support, speed is adjustable and precisely known, and a specialist stands by to intervene. The APPAHOCA-2 investigators are essentially testing whether a piece of equipment more often associated with gyms can be safely redeployed to the surgical ward in the service of older cancer patients.

The study has cleared the standard regulatory hurdles that govern clinical research in France. It received ethical approval from the Comité de Protection des Personnes Ile de France I in December 2023, and the French Health Regulatory Authority, the ANSM, validated the investigation’s compliance with the European Union Medical Device Regulation. The trial is registered on ClinicalTrials.gov under identifier NCT06201884, with registration dated 2 January 2024, and the protocol has reached version 4.1 as of December 2025. Funding comes from the French Ministry of Health through the interregional hospital clinical research program, and the protocol itself was peer-reviewed by the funding body before the trial was granted support. The funding agency, the authors note, played no role in the design, conduct, or analysis of the study. All participants will receive an information file from their surgeons or anesthesiologists and must provide written informed consent before any study-related assessment begins.

The trial’s phase II designation signals its purpose: this is an effectiveness and feasibility study intended to establish whether the intervention works well enough to justify a larger definitive trial. Beyond the primary endpoint, the investigators plan to explore how the level of effectiveness relates to the number and duration of walking sessions patients actually complete during their recovery, a dose-response question that could shape how such programs are prescribed in the future. If patients who accumulate more minutes on the treadmill recover their walking capacity more reliably, that would support structured, supervised early mobilization as a standard component of postoperative care for older adults. If the relationship is weak or absent, the field will need to look elsewhere, perhaps toward nutritional optimization or other rehabilitation strategies.

For now, the value of APPAHOCA-2 lies in its clarity of purpose. It takes a problem that is easy to overlook, the quiet physical decline of older surgical patients during hospital stays, and subjects a simple remedy to rigorous measurement. The six-minute walk test, the geriatric assessments, the 90-day follow-up, and the careful tracking of sleep, mood, cognition, and nutrition together form a portrait of recovery that is far richer than length of stay alone could provide. As populations age and cancer surgery is performed increasingly on patients in their seventies and eighties, the question the French team is asking will only grow more urgent: can the hospital stay itself become part of the cure rather than an obstacle to it? The answer, the researchers hope, may begin with a few supervised steps on a treadmill the day after surgery.

Subject of Research: Early supervised treadmill walking to restore physical fitness in older inpatients recovering from cancer surgery

Article Title: Effectiveness of early supervised walking sessions on a walking treadmill in older inpatients after cancer surgery: study protocol for the APPAHOCA-2 trial

Article References: Solem-Laviec, H., Beauplet, B., Leconte, A., Coquerel, A., Demeude, F., Thuard, O., Ruet, A., Bastit, V., Babin, E., Varatharajah, S., Guilloit, J.-M., Fauvet, R., Waeckel, T., Perrier, J., Lequesne, J., & Clarisse, B. (2026). Effectiveness of early supervised walking sessions on a walking treadmill in older inpatients after cancer surgery: study protocol for the APPAHOCA-2 trial. BMC Geriatrics. https://doi.org/10.1186/s12877-026-08422-6

Image Credits: AI Generated

DOI: 10.1186/s12877-026-08422-6

Keywords: geriatric oncology, cancer surgery, treadmill walking, early mobilization, six-minute walk test, rehabilitation, sarcopenia, gait speed, older inpatients, clinical trial, physical deconditioning, APPAHOCA-2

The problem with existing fall risk assessments is stark. Most screening tools rely on physical performance measures such as gait and balance testing, with cutoff points derived from studies of adults aged 65 and older that included few or no participants over 90. Applied to a 93-year-old, nearly every one of these tools would flag the patient as high risk. But fewer than half of people aged 90 and older actually fall each year. Labeling everyone as high risk is not merely imprecise; it is actively harmful. Hospital patients tagged as fall risks are often kept in bed without assistance, which accelerates deconditioning and immobility. A high-risk label can also make it harder for clinicians to justify discharge home or to intensive rehabilitation, limiting access to restorative care for an already vulnerable group and feeding the already high rates of institutionalization among the oldest old.

To cut through this diagnostic fog, the research team led by Katherine A. Colcord and María M. Corrada analyzed 1,099 participants from The 90+ Study—749 women and 350 men with a mean age of 93.2 years. The cohort, largely drawn from surviving members of the Leisure World Cohort Study, a landmark epidemiological project begun in 1981 in a California retirement community, was evaluated every six months. At each visit, examiners recorded falls reported by participants or their informants, administered the Four-Meter Walk Test, and assigned a cognitive diagnosis ranging from normal to cognitive impairment no dementia (CIND) to dementia. The researchers then classified each participant into four groups: neither slow gait nor impaired cognition, slow gait alone, impaired cognition alone, or both.

The gait measure was deliberately tailored to this age group. Rather than using the conventional 1.0 meter-per-second threshold developed in younger populations—a cutoff that would have classified 93 percent of the study participants as slow walkers—the team defined slow gait as a speed below the sex-specific median: 0.56 meters per second for women and 0.69 meters per second for men. These values closely match published reference percentiles for adults over 90, allowing the investigators to distinguish relatively slower walkers within the cohort rather than simply sorting nearly everyone into the same bucket. The Four-Meter Walk Test itself is elegantly simple: participants walk four marked meters at their usual pace, timed from the moment the first foot crosses the starting tape to when it crosses the finish line, with buffer zones for acceleration and deceleration.

Using generalized linear mixed regression models with a negative binomial distribution and log person-years as an offset, the team calculated incidence rate ratios comparing each gait-cognition group against the reference group with neither deficit. The results, published in September 2026, revealed a striking sex difference. Among women, slow gait alone raised fall risk by 33 percent and the combination of slow gait and impaired cognition by 35 percent, but impaired cognition by itself showed no significant association. Among men, all three categories mattered: slow gait alone raised risk by 70 percent, impaired cognition alone by 75 percent, and the combination by a full 134 percent compared with men who had neither deficit. Adjusting for demographics and for a comorbidity index spanning seventeen chronic conditions did not meaningfully change these patterns, suggesting the associations were not driven by overall disease burden.

The sex difference persisted in sensitivity analyses designed to probe its robustness. Among the 604 participants who walked without any assistive device—people who might not otherwise be flagged as vulnerable—the combination of slow gait and impaired cognition was a powerful predictor, raising fall risk more than twofold overall, with significant effects in both women and men. In the subgroup of 596 participants who reported no falls at or before their baseline visit, impaired cognition and the combined deficit remained significant predictors in men but not women, indicating that the male associations were not simply an artifact of a prior history of falling. When the researchers re-included 110 participants who were unable to complete the walk test—counting them as slow walkers, since inability to finish likely reflects poor physical function—the combined group predicted falls in both sexes, and the magnitude of the risk estimates grew slightly, hinting that the true associations may be even stronger than observed.

The longitudinal trajectories added another layer of insight. In men, fall rates climbed steadily over time in the groups with neither deficit, slow gait alone, or impaired cognition alone, but remained consistently high from the start in the combined group. In women, fall rates rose significantly only in the group with neither deficit and stayed relatively flat elsewhere. This pattern carries a double message: the combination of slow gait and impaired cognition identifies people whose risk is persistently elevated, while even those who appear entirely healthy at 93 face rising risk as time passes. Continued fall screening, the authors argue, must not stop at age 90.

Why should cognition and gait be more predictive together than either alone? Several mechanisms have been proposed. Cognitive impairment erodes judgment and self-awareness, leading people to place themselves in precarious situations they can no longer safely navigate. Neuropathological changes in the brain that drive cognitive decline may simultaneously drive physical decline, so cognition testing can catch subtle deterioration in balance, postural control, and reaction time that gait speed alone misses. Medications matter too: cholinesterase inhibitors prescribed for cognitive impairment can cause dizziness and lightheadedness, indirectly raising fall risk. The findings echo earlier work in younger seniors—a meta-analysis of 6,204 participants with a mean age of 74.9 found a 44 percent higher fall risk in people with both slow gait and subjective cognitive complaints—but the new study extends this evidence into the ninth decade of life, where the stakes are highest.

The sex difference itself may have a surprisingly practical explanation. In the cohort, women used walkers more often than canes, while men favored canes. Canes demand greater cognitive capacity for sequencing and timing during gait and require more energy expenditure, and previous work from the same group found that walker use was associated with a declining fall rate over time while cane use was associated with an increasing one. A cane may simply be the wrong prescription for a cognitively impaired 93-year-old, and the authors suggest that referral to a clinician trained in gait analysis before prescribing an assistive device could itself become a fall prevention strategy. The study is not without limitations—falls were self-reported at six-month intervals, which may have led cognitively impaired participants to underreport and thus underestimate the cognitive effect, and the cohort was 98.6 percent White—but its inclusion of homebound participants, with examiners traveling even out of state, makes it unusually representative of the real 90-plus population.

The implications reach well beyond the clinic. As the oldest old become a larger share of society, distinguishing who truly needs fall precautions from who does not could preserve mobility, independence, and dignity for millions. This study shows that a stopwatch, a four-meter hallway, and a careful cognitive assessment—together, not separately—can do what decades of age-based screening could not: find the people who are genuinely about to fall, before they do.

Subject of Research: The combined role of gait speed and cognitive impairment in predicting fall risk among adults aged 90 and older

Article Title: Enhancing fall risk assessment in the oldest old: The interplay of cognition and gait speed

Article References: Colcord, K. A., Kristinsson, H. B., Jiang, L., Melikyan, Z. A., Al-darsani, Z., Falvey, J. R., Kawas, C. H., & Corrada, M. M. (2026). Enhancing fall risk assessment in the oldest old: The interplay of cognition and gait speed. GeroScience. https://doi.org/10.1007/s11357-026-02516-0

Image Credits: AI Generated

DOI: 10.1007/s11357-026-02516-0

Keywords: fall risk, oldest old, gait speed, cognitive impairment, dementia, The 90+ Study, geroscience, fall prevention, aging, sex differences, Four-Meter Walk Test, assistive devices

The review was led by Xiaoxia Wei of the Chinese Academy of Medical Sciences and Peking Union Medical College, working with Ruitai Shao, Yves Rolland, Bruno Vellas and Philipe de Souto Barreto, a team anchored at IHU HealthAge in Toulouse, France. The authors conducted a structured PubMed search with a final cutoff of December 31, 2025, and formally appraised study quality using the Newcastle-Ottawa Scale and the Joanna Briggs Institute checklist, finding acceptable methodological quality for most of the included research. Their conclusion is striking in its breadth: Alzheimer’s-related pathology and neurodegeneration appear to have functional correlates beyond cognition, with the pattern of associations varying by biomarker type, by the capacity domain examined and by study design.

To understand why this matters, it helps to unpack the two pillars of the analysis. Intrinsic capacity, a concept championed by the WHO in its 2015 world report on ageing and health, describes the sum total of an individual’s locomotion, cognition, vitality, psychological well-being, hearing and vision. It is increasingly measured as a composite score that predicts disability, hospital admission and mortality. Alzheimer’s biomarkers, meanwhile, now span a well-validated arsenal: amyloid-beta and tau proteins measured in cerebrospinal fluid or blood, neurofilament light chain as a marker of neuronal injury, glial fibrillary acidic protein as a gauge of astrocytic activation, structural MRI to quantify atrophy, and fluorodeoxyglucose positron emission tomography to map the brain’s faltering glucose metabolism. The 2024 revised diagnostic criteria from the Alzheimer’s Association have pushed the field toward defining the disease biologically, which makes the question of what those biology markers do to everyday function increasingly urgent.

The evidence on composite intrinsic capacity scores remains thin, with only two studies addressing it directly, but the longitudinal signals are provocative. Lower intrinsic capacity was associated with elevated plasma p-tau181, a phosphorylated form of tau protein that has become one of the most reliable blood indicators of Alzheimer’s pathology. Higher baseline neurofilament light chain predicted steeper subsequent decline in intrinsic capacity over follow-up, suggesting that ongoing neuronal injury may be a harbinger of global functional deterioration. Notably, the ratio of plasma amyloid-beta 42 to amyloid-beta 40 showed no clear association with composite capacity, hinting that amyloid burden alone may be a weaker predictor of whole-person function than tau and neurodegeneration markers, a hierarchy that mirrors what the field has learned about cognition itself.

Locomotion emerged as one of the most consistently mapped domains, examined in 30 of the included studies. Higher cerebral amyloid-beta deposition was associated with poorer locomotion, especially slower gait speed, more consistently than any other biomarker modality. This finding aligns with a growing body of work showing that gait slowing can precede cognitive decline by several years and that amyloid burden predicts lower extremity performance decline even in cognitively unimpaired older adults. Studies from cohorts including the Atherosclerosis Risk in Communities study and memory clinic populations in Norway linked cerebrospinal fluid amyloid and tau to mobility measures, while imaging work connected regional brain amyloid to gait speed in elderly individuals without dementia. The mechanistic picture is still forming, but the convergence of PET imaging, fluid biomarkers and performance-based measures paints amyloid as a quiet saboteur of movement.

Handgrip strength and vitality, the domain encompassing energy, nutrition and muscle function, told a complementary story. Higher levels of tau biomarkers and neurofilament light chain were more often associated with lower or declining handgrip strength across the reviewed literature. A 12-year cohort study published in The Lancet Healthy Longevity traced blood biomarkers of Alzheimer’s disease against long-term muscle strength trajectories in community-dwelling older adults, and separate analyses found neurofilament light chain elevated in patients with severe sarcopenia and associated with muscle mass and strength in middle-aged and older adults. Neurofilament light chain, which leaks into blood when axons are damaged, appears to function as a shared signal of nervous system wear that registers in the grip of a hand as much as in a memory test.

Depressive symptoms were the most intensively studied non-cognitive domain, appearing in 49 of the 119 studies, and they produced some of the review’s most consistent longitudinal findings. Lower fluid amyloid-beta 42, greater cerebral amyloid deposition and subsequent brain atrophy were all linked to depressive symptoms over time. The relationship runs in both directions conceptually: some studies found that amyloid burden predicted incident depressive symptoms in cognitively normal older adults, while others documented that depressive symptom trajectories tracked with amyloid and cerebral glucose metabolism. Work from the Framingham Heart Study connected midlife depressive symptoms with regional amyloid and tau decades later, and a 2025 study found depressive symptoms correlating with tau accumulation rates in amyloid-positive adults. The authors caution that disentangling depression as prodrome, consequence or comorbidity of Alzheimer’s biology remains one of the field’s thorniest challenges, but the longitudinal consistency of the amyloid and atrophy signals suggests the association is not merely reverse causation or shared vascular risk.

Hearing impairment, examined in 29 studies, was linked mainly to higher tau and neurofilament light chain, reduced glucose metabolism on FDG-PET, and brain atrophy. Longitudinal work showed that age-related hearing loss accelerated cerebrospinal fluid tau levels and brain volume loss, and large imaging analyses associated hearing impairment with smaller total brain volume, temporal lobe volume loss and hippocampal shrinkage. Yet the amyloid story for hearing is muddled: several studies found no link between hearing loss and cerebrospinal fluid amyloid-beta or p-tau181, and at least one reported no influence of hearing loss on brain amyloid at all. This modality-specific divergence matters, because it suggests that different sensory and functional declines may index different arms of the Alzheimer’s pathophysiological cascade, with hearing tracking neurodegeneration more tightly than amyloidosis. Evidence for vision impairment was almost totally absent, with a single study addressing it, a gap the authors flag as a priority for future research.

The review’s implications cut in two directions. Clinically, if biomarkers of Alzheimer’s biology predict declines in gait, grip, mood and hearing, then blood tests that are rapidly entering routine practice could eventually help identify older adults at risk of losing functional independence, not just those at risk of memory loss, and interventions targeting intrinsic capacity could be timed against measurable pathology. Scientifically, the findings reinforce a view of Alzheimer’s as a whole-body, whole-life process rather than a purely cognitive one, echoing the Lancet Commission’s emphasis on dementia prevention across the life course. The authors are careful about limitations: the evidence is largely observational, heterogeneous in design, and heavily weighted toward cross-sectional analyses, with longitudinal data scarce for several domains. Still, with reference centiles for intrinsic capacity now available for monitoring health outcomes in primary care, the prospect of pairing a simple capacity assessment with a blood draw to catch functional decline early is moving from speculative to plausible, and this synthesis provides the evidentiary map for getting there.

Subject of Research: Associations between Alzheimer's disease biomarkers and non-cognitive domains of intrinsic capacity in older adults

Article Title: Alzheimer’s disease biomarkers in relation to non-cognitive domains within the intrinsic capacity framework: a narrative review

Article References: Wei, X., Shao, R., Rolland, Y., Vellas, B., & de Souto Barreto, P. (2026). Alzheimer’s disease biomarkers in relation to non-cognitive domains within the intrinsic capacity framework: a narrative review. GeroScience. https://doi.org/10.1007/s11357-026-02544-w

Image Credits: AI Generated

DOI: 10.1007/s11357-026-02544-w

Keywords: Alzheimer's disease, biomarkers, intrinsic capacity, amyloid-beta, tau protein, neurofilament light chain, GFAP, depressive symptoms, gait speed, hearing impairment, handgrip strength, healthy aging