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Background: A socioeconomic gradient exists in the utilisation of total hip replacements (THR) and total knee replacements (TKR) for osteoarthritis. However, the relations between socioeconomic status (SES) and time to THR or TKR is unknown. Aim: To describe the association between SES and time to THR and TKR. Methods: One thousand and seventy‐two older adults residing in Tasmania, Australia, were studied. Incident primary THR and TKR were determined by data linkage to the Australian Orthopaedic Association National Joint Replacement Registry. At baseline, each participant's area‐level SES was determined using the Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD) from the Australian Bureau of Statistics' 2001 census data. The IRSAD was analysed in two ways: (i) categorised into quartiles, whereby quartile 1 represented the most socioeconomically disadvantaged group; and (ii) the cohort dichotomised at the quartile 1 cut‐point. Results: The mean age was 63.0 (±7.5) years and 51% were women. Over the median follow up of 12.9 (interquartile range: 12.2–13.9) years, 56 (5%) participants had a THR and 79 (7%) had a TKR. Compared with the most disadvantaged quartile, less disadvantaged participants were less likely to have a THR (i.e. less disadvantaged participants had a longer time to THR; hazard ratio (HR): 0.56; 95% confidence interval (CI) 0.32, 1.00) but not TKR (HR: 0.90; 95% CI 0.53, 1.54). However, the former became non‐significant after adjustment for pain and radiographic osteoarthritis, suggesting that the associations may be mediated by these factors. Conclusions: The present study suggests that time to joint replacement was determined according to the symptoms/need of the participants rather than their SES. [ABSTRACT FROM AUTHOR]

Sedentary time is prevalent following stroke, limiting functional improvement, and increasing cardiovascular risk. At discharge we examined: 1) change in sedentary time and activity over the following 3 months' and 2) physical, psychological or cognitive factors predicting any change. A secondary aim examined cross-sectional associations between factors and activity at 3 months. People with stroke (n = 34) were recruited from two rehabilitation units. An activity monitor (ActivPAL3) was worn for 7 days during the first week home and 3 months later. Factors examined included physical, psychological, and cognitive function. Linear mixed models (adjusted for waking hours) were used to examine changes in sedentary time, walking, and step count over time. Interaction terms between time and each factor were added to the model to determine if they modified change over time. Linear regression was performed to determine factors cross-sectionally associated with 3-month activity. ActivPAL data were available at both time points for 28 (82%) participants (mean age 69 [SD 12] years). At 3 months, participants spent 39 fewer minutes sedentary (95%CI −70,-8 p =.01), 21 minutes more walking (95%CI 2,22 p =.02) and completed 1112 additional steps/day (95%CI 268,1956 p =.01), compared to the first week home. No factors predicted change in activity. At 3 months, greater depression (β 22 mins (95%CI 8,36) p =.004) and slower gait speed (β − 43 mins 95%CI −59,-27 p ≤ 0.001) were associated with more sedentary time and less walking activity, respectively. Sedentary time reduced and walking activity increased between discharge home and 3 months later. Interventions targeting mood and physical function may warrant testing to reduce sedentary behavior 3 months following discharge. [ABSTRACT FROM AUTHOR]

Background: Gait slowing and cognitive decline are both common in older people. Although cross-sectionally related, the longitudinal associations between specific cognitive functions and gait speed are less well understood. We aimed to determine whether decline in specific cognitive domains are associated with change in gait speed.Methods: Participants aged 60-85, randomly selected from the electoral roll, were assessed twice over 3 years. Gait speed was obtained using the GAITRite walkway. Raw scores from a cognitive battery were subjected to principal component analyses deriving summary domains of executive function, processing speed, memory, and visuospatial ability. Multivariable linear regression was used to examine the associations between change in each cognitive domain and change in gait speed, adjusting for covariates and stratifying for the presence of baseline cognitive impairment.Results: Mean age at baseline was 71.1 years (SD = 6.7) and 56% (159/284) were men. Mean follow-up was 2.55 (0.47) years. Decline in executive function, but not other cognitive domains (p > .05), was associated with decline in gait speed, cm/s (β = -3.55, 95% CI = -5.49, -1.61; p < .001), both in the presence and absence of baseline cognitive impairment. Stronger associations were seen for those with baseline multiple domain cognitive impairment (β = -6.38, 95% CI = -12.49, -0.27) and nonamnestic single-domain cognitive impairment (β = -7.74, 95% CI = -14.76, -0.72).Conclusion: Decline in nonamnestic function (specifically executive function) was associated with decline in gait speed irrespective of the presence of baseline cognitive impairment. Strategies to improve or maintain executive function may prevent gait slowing. [ABSTRACT FROM AUTHOR]

Objectives To investigate longitudinal associations between changes in brain structure and gait decline. Design Longitudinal. Setting Population-based Tasmanian Study of Cognition and Gait. Participants Two hundred twenty-five individuals aged 60 to 86 (mean age 71.4 ± 6.8) randomly selected from the electoral roll with baseline and follow-up data. Measurements Volumes of gray matter, white matter, hippocampi, and white matter lesions ( WML) were estimated using automated segmentation from magnetic resonance imaging ( MRI). Gait variables were measured using a computerized walkway. Linear regression was used to estimate the association between change in brain MRI measures and change in gait. Time between measurements, age, sex, BMI, education level, total intracranial volume, baseline infarcts, and medical history were used as baseline covariates. Results Mean follow-up was 30.6 months. White matter atrophy was associated with a decline in gait speed ( P = .001), step length ( P = .005), and cadence ( P = .001). WML progression was associated with a decline in gait speed ( P = .04), and its association with decline in step length was stronger with greater baseline age ( P for interaction = .04). Hippocampal atrophy was associated with a decline in gait speed ( P = .006) and step length ( P = .001). Total gray matter atrophy was associated with decline in cadence in those with cerebral infarcts ( P for interaction = .02). Conclusion These are the first longitudinal data demonstrating the relative contributions of brain atrophy and WML progression to gait decline in older people. Effect modification according to age and infarcts suggests a contribution of reduced physiological and brain reserve. Interventions targeting brain health may be important in preventing mobility decline in older people. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

Background. Adequate mobility is essential to maintain an independent and active lifestyle. The aim of this cross-sectional study is to examine the associations of age with temporal and spatial gait variables in a population-based sample of older people, and whether these associations are modified by sex. Methods. Men and women aged 60-86 years were randomly selected from the Southern Tasmanian electoral roll (n = 223). Gait speed, step length, cadence, step width, and double-support phase were recorded with a GAITRite walkway. Regression analysis was used to model the relationship between age, sex, and gait variables. Results. For men, after adjusting for height and weight, age was linearly associated with all gait variables (p < .05) except cadence (p = .11). For women, all variables demonstrated a curvilinear association, with age-related change in these variables commencing during the 7th decade. Significant interactions were found between age and sex for speed (p = .04), cadence (p = .01), and double-support phase (p = .03). Conclusion. Associations were observed between age and a broad range of temporal and spatial gait variables in this study. These associations differed by sex, suggesting that the aging process may affect gait in men and women differently. These results provide a basis for further research into sex differences and mechanisms underlying gait changes with advancing age. [ABSTRACT FROM AUTHOR]

An inflammatory diet is related to poorer cognition, but the underlying brain pathways are unknown. The aim of this study was to examine associations between the Energy-Adjusted Dietary Inflammatory Index (E-DII) and brain volume, small vessel disease, and cognition in people with and without type 2 diabetes mellitus (T2DM). This is a secondary cross-sectional analysis of data from the Cognition and Diabetes in Older Tasmanians study. This study included 641 participants (n = 326 with T2DM) enrolled between 2005 and 2011 from Tasmania, Australia. The E-DII was computed from the 80-item Dietary Questionnaire for Epidemiological Studies, version 2. Brain volumes (gray matter, white matter, and white matter hyperintensities), infarcts, and microbleeds were obtained from magnetic resonance imaging. Global cognition was derived from a comprehensive battery of neuropsychological tests. Logistic and linear regressions were performed to examine associations between E-DII and brain measures and a global cognitive score, adjusting for demographics, energy, T2DM, mood, ambulatory activity, and cardiovascular risk factors. An E-DII × T2DM interaction term was tested in each model. The mean (standard deviation) age of participants was 69.8 (7.4) years. There were no associations between the E-DII and any of the brain structural measures or global cognitive function in fully adjusted models. There was a modification effect for T2DM on the association between E-DII and gray matter volume (T2DM: β = 1.38, 95% CI –3.03 to 5.79; without T2DM: β = –4.34, 95% CI, –8.52 to –0.16), but not with any of the other outcome measures. In this cross-sectional study, E-DII was not associated with brain structure or global cognition. In 1 of the 7 outcomes, a significant modification effect for T2DM was found for the associations between E-DII and gray matter. Future prospective studies are needed to clarify the associations between diet-related inflammation and brain health. [ABSTRACT FROM AUTHOR]

Background: Gait variability is a marker of cognitive decline. However, there is limited understanding of the cortical regions associated with gait variability. We examined associations between regional cortical thickness and gait variability in a population-based sample of older people without dementia., Method: Participants (n = 350, mean age 71.9 ± 7.1) were randomly selected from the electoral roll. Variability in step time, step length, step width, and double support time (DST) were calculated as the standard deviation of each measure, obtained from the GAITRite walkway. Magnetic resonance imaging (MRI) scans were processed through FreeSurfer to obtain cortical thickness of 68 regions. Bayesian regression was used to determine regional associations of mean cortical thickness and thickness ratio (regional thickness/overall mean thickness) with gait variability., Results: Smaller global cortical thickness was only associated with greater step width and step time variability. Smaller mean thickness in widespread regions important for sensory, cognitive, and motor functions were associated with greater step width and step time variability. In contrast, smaller thickness in a few frontal and temporal regions were associated with DST variability and the right cuneus was associated with step length variability. Smaller thickness ratio in frontal and temporal regions important for motor planning, execution, and sensory function and greater thickness ratio in the anterior cingulate was associated with greater variability in all measures., Conclusions: Examining individual cortical regions is important in understanding the relationship between gray matter and gait variability. Cortical thickness ratio highlights that smaller regional thickness relative to global thickness may be important for the consistency of gait., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The contribution of cerebral small vessel disease (cSVD) to the pathogenesis of frailty remains uncertain. We aimed to examine the associations between cSVD with progression of frailty in a population-based study of older people., Methods: People aged between 60 and 85 years were randomly selected form the electoral roll to participate in the Tasmanian Study of Cognition and Gait. Participants underwent self-reported questionnaires, objective gait, cognitive and sensorimotor testing over three phases ranging between 2005 and 2012. These data were used to calculate a 41-item frailty index (FI) at three time points. Baseline brain magnetic resonance imaging was performed on all participants to measure cSVD. Generalized mixed models were used to examine associations between baseline cSVD and progression of frailty, adjusted for confounders of age, sex, level of education, and total intracranial volume., Results: At baseline (n = 388) mean age was 72 years (SD = 7.0), 44% were female, and the median FI score was 0.20 (interquartile range [IQR] 0.12, 0.27). In fully adjusted models higher burden of baseline white matter hyperintensity (WMH) was associated with frailty progression over 4.4 years (β = 0.03, 95% CI: 0.01, 0.05; p = .004) independent of other SVD markers. Neither baseline infarcts (p = .23), nor microbleeds at baseline (p = .65) were associated with progression of frailty., Conclusions: We provide evidence for an association between baseline WMHs and progression of frailty. Our findings add to a growing body of literature suggesting WMH is a marker for frailty., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Frailty is a prevalent geriatric condition associated with poor health outcomes. The pathogenesis of frailty is incompletely understood. We aimed to evaluate the relationship between cerebral small vessel disease (SVD) and frailty., Methods: People aged between 60 and 85 years were randomly selected from the electoral roll into the Tasmanian Study of Cognition and Gait. Participants completed standardized questionnaires regarding medical history and underwent objective sensorimotor, gait, and cognitive testing. These data were used to calculate a frailty index score. Magnetic resonance imaging was performed on all participants to measure SVD. Automated quantification was used to measure white matter hyperintensities (WMH), with manual consensus for subcortical infarction (SI) and cerebral microbleeds (CMB). Multivariable linear regression was used to determine the association between SVD and frailty., Results: The mean age of the sample (n = 388) was 72.0 years (SD 7.0), 44% (172/388) were female and the median Frailty Index was 0.20 (interquartile range 0.12, 0.27). WMH, SI, and CMB in unadjusted models were positively associated with higher frailty scores (p < .05). In final models including all brain variables, higher burden of WMH (β = 2.16; 95% confidence interval [CI] 0.75, 3.57; p = .003), but not SI (β = 2.96; 95% CI -0.44, 6.35; p = .09) or CMB (β = -0.46; 95% CI -4.88, 3.96; p = .84), was independently associated with a higher frailty score., Conclusions: We provide cross-sectional evidence for a positive association between larger burden of WMH and frailty. Longitudinal design is required to determine the temporality of this relationship., (© The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Greater volume of cerebral white matter hyperintensities (WMH) of presumed vascular origin may affect postural control and gait. WMH measured at one time point predicts an increased risk of incident multiple falls. However, it is unknown whether WMH progression increases falls risk. We hypothesized that the progression of WMH would be associated with a greater risk of multiple falls., Methods: A population-based sample aged more than 60 years was randomly selected from the electoral roll and followed up 2.5 years apart with two phases of measurement. Magnetic resonance imaging scans from both time points were subjected to automated segmentation to derive WMH volumes. Falls were recorded prospectively over 12 months after the second magnetic resonance imaging measurement. A generalized linear model was used to estimate the relative risk of multiple falls associated with WMH progression adjusted for confounders., Results: There were 187 people (mean age 70.4, SD 6.5) with a mean follow-up of 2.5 (SD 0.4) years. Over 12 months, 35 (18.7%) participants reported multiple falls. A greater progression of WMH was associated with an increased risk of multiple falls (adjusted relative risk 1.30, 95% confidence interval 1.00-1.70, p = .05) independent of baseline WMH volume, duration of follow-up, age, sex, and total intracranial volume. This association was unchanged when adjusted for medical history, peripheral sensorimotor factors, gait speed, cognition, medications, mood, and magnetic resonance imaging infarcts., Conclusion: Greater WMH progression independently increased the risk of multiple falls. Interventions to slow the progression of WMH may be successful in reducing this risk., (© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: To determine whether there is a relationship between daily defined dose (DDD) of antihypertensive drugs and the risk of falls., Design: Prospective population-based cohort study., Setting: Tasmanian Study of Cognition and Gait, Australia., Participants: Participants aged 60 to 86 randomly selected from the electoral roll., Measurements: Antihypertensive dose was quantified by estimating DDD, allowing standardized comparison of dosage between drug classes. Falls were identified prospectively over 12 months. The relative risk (RR) of falls associated with DDD was estimated using log binomial regression adjusting for age, sex, body mass index, education, cardiovascular history, and other risk factors for falls., Results: Participants (N=409) had a mean age of 72.0±6.9, and 56% were male. Mean baseline blood pressure was 142/80 mmHg, and 54% were taking antihypertensive medications. One hundred sixty-one participants (39%) fell over the 12 months. Those who fell were on a higher DDD of antihypertensives (1.51±2.16 than those who did not (1.03±1.42) (P=.007). Higher DDD was independently associated with greater fall risk (RR=1.07, 95% confidence interval (CI)=1.02-1.11; P=.004), with a 48% greater risk in those with a DDD of more than 3 (RR=1.48, 95% CI=1.06-2.08; P=.02), particularly in those with a history of stroke (P for interaction .01). This effect remained even after excluding those not taking antihypertensives or stratifying according to presence of hypertension and medication use., Conclusion: Higher dose of antihypertensive medication is independently associated with falls in older people, particularly in those with a history of previous stroke, and with more than three standard units conferring the highest risk., (© 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.)

Background: There is a poor understanding of the interplay between cognitive and physiological functions in leading to falls. We hypothesized that poorer physiological function would modify the effect of poorer cognitive function on increased risk of falling in older people., Methods: A range of cognitive (executive function/attention, memory, processing speed, and visuospatial ability) and physiological functions (vision, proprioception, sway, leg strength, reaction time) were measured using standardized tests in 386 randomly selected adults aged 60-86. Incident falls were recorded over 12 months. Log-multinomial regression was used to model the relationships and test for interactions between cognition and physiological function in explaining the risk of single or multiple falls., Results: Overall, 94 people (24.4%) had a single fall, and 78 (20.2%) had multiple falls. No significant associations were observed between cognitive function and the risk of single falls. The risk of multiple falls was increased with poorer function in Stroop dot time (RR = 1.03, 95% CI [1.01, 1.05], p = .002) and Stroop word time (RR = 1.02 [1.01, 1.03], p = .001) and reduced with better function in Category Fluency (RR = 0.94 [0.91, 0.98], p = .001) and visuospatial function (RR = 0.95 [0.92, 0.98], p < .001). These associations were amplified by the presence of greater body sway, less ambulatory physical activity, slower reaction time and gait speed, weaker muscle strength, and poorer visual contrast (p for interactions <.05)., Conclusions: Preventing falls due to physiological impairments in community-dwelling older people may need to be tailored based on cognitive impairment, a key factor in their inability to compensate for physical decline.

Background: 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., Methods: 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., Results: 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., Conclusions: 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.

Background: the study of factors associated with age-related gait decline may assist in developing methods to preserve mobility in older people., Objective: to examine the associations between sensorimotor factors relevant to ageing and gait in the general older population., Design: cross-sectional population-based study., Methods: participants aged 60-86 years (n = 278) were randomly selected using electoral roll sampling. Sensorimotor factors (quadriceps strength, reaction time, postural sway, proprioception and visual contrast sensitivity) were measured using the Physiological Profile Assessment. Gait variables (speed, cadence, step length, double support phase and step width) were recorded with a GAITRite walkway. Linear regression was used to model relationships between sensorimotor and gait variables., Results: mean age of participants was 72.4 (7.0) years with 154 (55%) males. Better quadriceps strength, reaction time and postural sway (in men) predicted faster gait speed due to their effects on step length and/or cadence. Body weight (in men) and visual contrast sensitivity (in women) were modifying factors in these relationships. Better postural sway, reaction time (in men) and quadriceps strength (in women) predicted reduced double support phase. Modifying factors were quadriceps strength (in men) and proprioception (in women). Postural sway was the sole predictor of step width and in women only., Conclusion: potentially modifiable sensorimotor factors were associated with a range of gait measures, with a different pattern of individual associations and interactions seen between the sexes. These results provide further mechanistic insights towards explaining age-related gait decline in the general older population.