Objectives: Our objective is to report prevalence of motoric cognitive risk syndrome (MCR), a newly described predementia syndrome characterized by slow gait and cognitive complaints, in multiple countries, and its association with dementia risk. Methods: Pooled MCR prevalence analysis of individual data from 26,802 adults without dementia and disability aged 60 years and older from 22 cohorts from 17 countries. We also examined risk of incident cognitive impairment (Mini-Mental State Examination decline ≥4 points) and dementia associated with MCR in 4,812 individuals without dementia with baseline Mini-Mental State Examination scores ≥25 from 4 prospective cohort studies using Cox models adjusted for potential confounders. Results: At baseline, 2,808 of the 26,802 participants met MCR criteria. Pooled MCR prevalence was 9.7% (95% confidence interval [CI] 8.2%–11.2%). MCR prevalence was higher with older age but there were no sex differences. MCR predicted risk of developing incident cognitive impairment in the pooled sample (adjusted hazard ratio [aHR] 2.0, 95% CI 1.7–2.4); aHRs were 1.5 to 2.7 in the individual cohorts. MCR also predicted dementia in the pooled sample (aHR 1.9, 95% CI 1.5–2.3). The results persisted even after excluding participants with possible cognitive impairment, accounting for early dementia, and diagnostic overlap with other predementia syndromes. Conclusion: MCR is common in older adults, and is a strong and early risk factor for cognitive decline. This clinical approach can be easily applied to identify high-risk seniors in a wide variety of settings.

Background: it is uncertain as to which measures of gait best predict those who are likely to fall. Our aim was to investigate the associations of gait and gait variability measures with incident falls risk. Methods: individuals aged 60–86 years (n = 412) were randomly selected from the Tasmanian electoral roll. Average gait and gait variability measures were collected on a computerised walkway. Falls were recorded prospectively over 12 months. Log multinomial regression was used to estimate the relative risk of single and multiple falls associated with gait measures. Covariates included age, sex, sensorimotor and cognitive measures, mood and medications. Results: in this population-based study greater intra-individual variability in step length and double-support phase were linearly associated with increased risk of multiple falls (P = 0.04). Non-linear associations with multiple falls were found for gait speed P = 0.002, cadence P = 0.004 and step time variability P = 0.03. None of the gait measures predicted risk of single falls. Conclusion: there is an increased risk of multiple falls, but not single falls, in older people with poorer gait. Specific measures of gait and gait variability seem to confer this risk and may be amenable to interventions designed to reduce the risk of multiple falls in older people.

Background: gait variability may be an important predictor of falls risk, but its characteristics are poorly understood. Objective: to examine the relationship between age and gait variability in a population-based sample of older people. Design: cross-sectional study. Methods: in people aged 60–86 years (n = 412), temporal and spatial gait variability measures were recorded with a GAITRite walkway. Regression analysis was used to model the relationship between age and gait variability adjusting for height, weight and self-reported chronic disease. Further adjustment was made for gait speed to examine its influence on the associations. Results: older age was associated with greater variability (P < 0.05) in all gait measures. All relationships were linear, except that between age and step time variability, which was curvilinear in women. Adjusting for gait speed changed the magnitude of the age coefficient by 62–86% for temporal variability measures, 25% for step length variability and 5–12% for step width variability. Conclusion: age is linearly associated with greater intra-individual gait variability for most gait measures, except for step time variability in women. Gait speed may mediate the association between age and temporal variability measures. Further study is needed to understand the factors responsible for the greater gait variability with ageing.

Objective: Our objective was to investigate whether type 2 diabetes mellitus (T2DM) influences neurodegeneration in a manner similar to Alzheimer disease (AD), by promoting brain β-amyloid (Aβ) or tau. Methods: We studied the cross-sectional associations of T2DM with cortical thickness, brain Aβ load, and CSF levels of Aβ and tau in a sample of people from the Alzheimer9s Disease Neuroimaging Initiative with diagnoses of AD dementia, mild cognitive impairment, and normal cognition. All (n = 816) received MRI, and a subsample underwent brain amyloid imaging (n = 102) and CSF Aβ and tau measurements (n = 415). Analyses were performed across and within cognitive diagnostic strata. Results: There were 124 people with T2DM (mean age 75.5 years) and 692 without T2DM (mean age 74.1 years). After adjusting for age, sex, total intracranial volume, APO ε4 status, and cognitive diagnosis, T2DM was associated with lower bilateral frontal and parietal cortical thickness (mL) (β = −0.03, p = 0.01). T2DM was not associated with ¹¹C Pittsburgh compound B standardized uptake value ratio (AU) in any brain region or with CSF Aβ₄₂ levels (pg/mL). T2DM was associated with greater CSF total tau (pg/mL) (β = 16.06, p = 0.04) and phosphorylated tau (β = 5.84, p = 0.02). The association between T2DM and cortical thickness was attenuated by 15% by the inclusion of phosphorylated tau. Conclusions: T2DM may promote neurodegeneration independent of AD dementia diagnosis, and its effect may be driven by tau phosphorylation. The mechanisms through which T2DM may promote tau phosphorylation deserve further study.

Gait impairments are associated with falls and loss of independence. The study of factors associated with poorer gait may assist in developing methods to preserve mobility in older people. The aim of this study was to examine the associations between a range of cognitive functions and gait and gait variability in a population-based sample of older people. Gait and intra-individual gait variability measures were obtained using the GAITRite walkway in a sample of older people, aged 60–85 years (N = 422), randomly selected from the Tasmanian electoral roll. Raw scores from a cognitive battery were subjected to principal component analyses deriving four summary domains: executive function/attention, processing speed, memory, and visuospatial ability. Multivariable linear regression was used to examine associations between cognitive domains and gait measures adjusting for age, sex, ambulatory activity, medication use, and mood. The mean age of the sample was 72.0 years (SD = 7.0), with 238 men (56%). Poorer executive function was independently associated with poorer performance in most absolute gait measures and with greater variability in double support phase and step time. Processing speed was associated with absolute gait measures and double support phase variability. Visuospatial ability was only associated with greater double support phase variability, independently of executive function and processing speed. Memory was not independently associated with any gait measure. In community-dwelling older people, executive function/attention and processing speed were associated with many aspects of gait, whereas visuospatial ability may only play a role in double support phase variability.