@article {1002, title = {Gait variability is associated with subclinical brain vascular abnormalities in high-functioning older adults.}, journal = {Neuroepidemiology}, volume = {29}, year = {2007}, month = {2007}, pages = {193-200}, abstract = {

BACKGROUND: Gait variability is an index of how much gait parameters, such as step length, change from one step to the next. Gait variability increases with age and in individuals affected by cortical and subcortical neurodegenerative conditions, and it is associated with falls and incident mobility disability. The brain anatomical correlates of gait variability have not been studied in high-functioning community-dwelling older adults.

METHODS: Gait variability and brain MRIs were assessed in a cohort of 331 men and women (mean age = 78.3 years) free from stroke, dementia or Parkinson{\textquoteright}s disease. Gait variability was computed for spatial parameters (step length and step width) and for temporal parameters (stance time). Subclinical brain vascular abnormalities were measured on brain MRIs as infarcts and white matter hyperintensities.

RESULTS: Greater variability of step length was associated with greater prevalence of infarcts, including infarcts in the basal ganglia, and with greater white matter hyperintensities severity, independent of age, gender, cognitive function and cardiovascular disease. Weaker associations were found between the other variability measures and the MRI measures.

CONCLUSION: In this group of older adults free from neurodegenerative diseases, a greater variability of step length was associated with greater burden of subclinical brain vascular abnormalities as defined by MRI.

}, keywords = {Accidental Falls, Activities of Daily Living, Aged, Aged, 80 and over, Basal Ganglia Cerebrovascular Disease, Brain, Cerebral Infarction, Comorbidity, Female, Gait Disorders, Neurologic, Geriatric Assessment, Health Surveys, Humans, Longitudinal Studies, Magnetic Resonance Imaging, Male, Mobility Limitation, Neurodegenerative Diseases, Neurologic Examination, Risk Factors, United States}, issn = {1423-0208}, doi = {10.1159/000111582}, author = {Rosano, Caterina and Brach, Jennifer and Studenski, Stephanie and Longstreth, W T and Newman, Anne B} } @article {988, title = {A regions-of-interest volumetric analysis of mobility limitations in community-dwelling older adults.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {62}, year = {2007}, month = {2007 Sep}, pages = {1048-55}, abstract = {

BACKGROUND: In community-dwelling older adults, greater mobility impairment is associated with greater burden of diffuse brain structural abnormalities, such as higher white matter hyperintensities. This study examined the association between gray matter volumes of regions related to motor control, gait, and balance and whether this association is independent of burden of white matter hyperintensities.

METHODS: A random sample of 327 participants of the Cardiovascular Health Study (78.3 +/- 4.1 years old, 57\% women) contributed brain magnetic resonance imaging (MRI) and mobility data. A brain imaging automated method measured gray matter volume in cerebellum, basal ganglia, and prefrontal and parietal cortex in both hemispheres. Gait speed was measured while walking 15 feet at usual pace. Standing balance was assessed by timing tandem stance. Associations between each region{\textquoteright}s volume and gait speed or balance were measured before and after adjustment for demographics, head size, cardiovascular risk factors, and 0-9 grading scores of white matter hyperintensities.

RESULTS: Smaller left cerebellum and left prefrontal regions were associated with slower gait, independently of covariates and of white matter hyperintensities. Smaller right putamen, right posterior superior parietal cortex, and both left and right cerebellum were associated with balance difficulty, independently of covariates and white matter hyperintensities.

CONCLUSIONS: Smaller gray matter volumes in regions crucial for motor control are associated with slower gait and poorer balance, and the association appears to be independent of other diffuse brain abnormalities such as white matter hyperintensities.

}, keywords = {Aged, Aged, 80 and over, Aging, Brain, Female, Gait, Humans, Magnetic Resonance Imaging, Male, Mobility Limitation, Postural Balance}, issn = {1079-5006}, doi = {10.1093/gerona/62.9.1048}, author = {Rosano, Caterina and Aizenstein, Howard J and Studenski, Stephanie and Newman, Anne B} } @article {1054, title = {Anemia is associated with the progression of white matter disease in older adults with high blood pressure: the cardiovascular health study.}, journal = {J Am Geriatr Soc}, volume = {56}, year = {2008}, month = {2008 Oct}, pages = {1867-72}, abstract = {

OBJECTIVES: To investigate whether anemia predicts worsening white matter hyperintensities (WMHs) in older community-dwellers.

DESIGN: Prospective cohort study.

SETTING: Older community-dwellers.

PARTICIPANTS: One thousand eight hundred forty-six Cardiovascular Health Study (CHS) participants (mean age 73.7 +/- 4.4, 41\% male, 15.6\% African American).

MEASUREMENTS: Participants had hemoglobin measured and brain magnetic resonance imaging (MRI) in 1992/93 and a second brain MRI in 1997/98. Anemia was defined according to World Health Organization criteria (hemoglobin <12 g/dL in women and <13 g/dL in men). Worsening WMHs were determined according to standardized side-by-side readings.

RESULTS: After 5 years, WMHs worsened in 517 participants (28\%). Progression was not associated with anemia in the whole sample, in sex or race strata, or in other prespecified subgroups (participants with renal dysfunction or diabetes mellitus), except in participants with high blood pressure (>or=140/90 mmHg). Of the 678 participants with high blood pressure, those with anemia (10.5\%) had a 1.79 times greater risk of WMHs worsening (95\% confidence interval=1.06-2.98; P for interaction between anemia and high blood pressure=.01) independent of demographics, baseline WMHs, cardiovascular risk factors and comorbidities, medications, renal function, inflammation, and incident stroke (logistic regression models). There was no greater risk in participants with anemia with normal blood pressure.

CONCLUSION: Anemia may contribute to worsening of WMHs in older adults with high blood pressure.

}, keywords = {Aged, Anemia, Brain, Cardiovascular Diseases, Disease Progression, Female, Humans, Hypertension, Leukoaraiosis, Magnetic Resonance Imaging, Male}, issn = {1532-5415}, doi = {10.1111/j.1532-5415.2008.01950.x}, author = {Inzitari, Marco and Studenski, Stephanie and Rosano, Caterina and Zakai, Neil A and Longstreth, William T and Cushman, Mary and Newman, Anne B} } @article {1058, title = {Impact of health perception, balance perception, fall history, balance performance, and gait speed on walking activity in older adults.}, journal = {Phys Ther}, volume = {88}, year = {2008}, month = {2008 Dec}, pages = {1474-81}, abstract = {

BACKGROUND AND PURPOSE: Disagreement currently exists regarding the contributions of various factors to physical activity in older adults. The purpose of this cross-sectional study was to investigate the simultaneous impact of psychological (health perception and balance perception) and physiological (gait speed, fall history, and balance performance) factors on walking activity in older adults.

SUBJECTS AND METHODS: This cross-sectional secondary data analysis included 2,269 community-dwelling older adults from the Cardiovascular Health Study. A series of simultaneous linear regression models were constructed to examine the association of walking activity with health and balance perception, gait speed, fall history, and balance performance after controlling for potential confounding factors.

RESULTS: Health and balance perception and gait speed were significantly related to walking activity after controlling for potential confounding factors. Participants who perceived both their health and their balance to be good walked more blocks per week than those who reported a discordant perception, who walked more than those who perceived both their health and their balance to be poor. Participants who walked at a normal speed walked more blocks per week than those who walked at a slow speed.

DISCUSSION AND CONCLUSION: The measure of physical activity used in this study included only walking, not other low- to moderate-intensity activities that are common in older adults. Health and balance perception and gait speed were associated with walking activity more so than fall history or balance performance after controlling for potential confounding factors.

}, keywords = {Accidental Falls, Aged, Aged, 80 and over, Attitude to Health, Cross-Sectional Studies, Female, Gait, Geriatric Assessment, Health Status, Humans, Male, Motor Activity, Multivariate Analysis, Perception, Postural Balance, Risk Assessment, Walking}, issn = {1538-6724}, doi = {10.2522/ptj.20080036}, author = {Talkowski, Jaime B and Brach, Jennifer S and Studenski, Stephanie and Newman, Anne B} } @article {1065, title = {The reliability and validity of measures of gait variability in community-dwelling older adults.}, journal = {Arch Phys Med Rehabil}, volume = {89}, year = {2008}, month = {2008 Dec}, pages = {2293-6}, abstract = {

OBJECTIVE: To examine the test-retest reliability and concurrent validity of variability of gait characteristics.

DESIGN: Cross-sectional study.

SETTING: Research laboratory.

PARTICIPANTS: Older adults (N=558) from the Cardiovascular Health Study.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Gait characteristics were measured using a 4-m computerized walkway. SD determined from the steps recorded were used as the measures of variability. Intraclass correlation coefficients (ICC) were calculated to examine test-retest reliability of a 4-m walk and two 4-m walks. To establish concurrent validity, the measures of gait variability were compared across levels of health, functional status, and physical activity using independent t tests and analysis of variances.

RESULTS: Gait variability measures from the two 4-m walks demonstrated greater test-retest reliability than those from the single 4-m walk (ICC=.22-.48 and ICC=.40-.63, respectively). Greater step length and stance time variability were associated with poorer health, functional status and physical activity (P<.05).

CONCLUSIONS: Gait variability calculated from a limited number of steps has fair to good test-retest reliability and concurrent validity. Reliability of gait variability calculated from a greater number of steps should be assessed to determine if the consistency can be improved.

}, keywords = {Activities of Daily Living, Aged, Cross-Sectional Studies, Disability Evaluation, Exercise, Female, Gait, Health Status, Humans, Male, Pennsylvania, Rehabilitation, Reproducibility of Results}, issn = {1532-821X}, doi = {10.1016/j.apmr.2008.06.010}, author = {Brach, Jennifer S and Perera, Subashan and Studenski, Stephanie and Newman, Anne B} } @article {970, title = {Stance time and step width variability have unique contributing impairments in older persons.}, journal = {Gait Posture}, volume = {27}, year = {2008}, month = {2008 Apr}, pages = {431-9}, abstract = {

Gait variability may have multiple causes. We hypothesized that central nervous system (CNS) impairments would affect motor control and be manifested as increased stance time and step length variability, while sensory impairments would affect balance and be manifested as increased step width variability. Older adults (mean+/-standard deviation (S.D.) age=79.4+/-4.1, n=558) from the Pittsburgh site of the Cardiovascular Health Study participated. The S.D. across steps was the indicator of gait variability, determined for three gait measures, step length, stance time and step width, using a computerized walkway. Impairment measures included CNS function (modified mini-mental state examination, Trails A and B, Digit Symbol Substitution, finger tapping), sensory function (lower extremity (LE) vibration, vision), strength (grip strength, repeated chair stands), mood, and LE pain. Linear regression models were fit for the three gait variability characteristics using impairment measures as independent variables, adjusted for age, race, gender, and height. Analyses were repeated stratified by gait speed. All measures of CNS impairment were directly related to stance time variability (p<0.01), with increased CNS impairment associated with increased stance time variability. CNS impairments were not related to step length or width variability. Both sensory impairments were inversely related to step width (p<0.01) but not step length or stance time variability. CNS impairments affected stance time variability especially in slow walkers while sensory impairments affected step width variability in fast walkers. Specific patterns of gait variability may imply different underlying causes. Types of gait variability should be specified. Interventions may be targeted at specific types of gait variability.

}, keywords = {Aged, Aged, 80 and over, Biomechanical Phenomena, Female, Gait Disorders, Neurologic, Humans, Linear Models, Longitudinal Studies, Male, Neuropsychological Tests, Postural Balance, Range of Motion, Articular, Risk Factors, Signal Processing, Computer-Assisted}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2007.05.016}, author = {Brach, Jennifer S and Studenski, Stephanie and Perera, Subashan and VanSwearingen, Jessie M and Newman, Anne B} } @article {1259, title = {Gait speed and survival in older adults.}, journal = {JAMA}, volume = {305}, year = {2011}, month = {2011 Jan 05}, pages = {50-8}, abstract = {

CONTEXT: Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates.

OBJECTIVE: To evaluate the relationship between gait speed and survival.

DESIGN, SETTING, AND PARTICIPANTS: Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34,485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6\%, women; and 79.8\%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s.

MAIN OUTCOME MEASURES: Survival rates and life expectancy.

RESULTS: There were 17,528 deaths; the overall 5-year survival rate was 84.8\% (confidence interval [CI], 79.6\%-88.8\%) and 10-year survival rate was 59.7\% (95\% CI, 46.5\%-70.6\%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95\% CI, 0.87-0.90; P < .001). Survival increased across the full range of gait speeds, with significant increments per 0.1 m/s. At age 75, predicted 10-year survival across the range of gait speeds ranged from 19\% to 87\% in men and from 35\% to 91\% in women. Predicted survival based on age, sex, and gait speed was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function or as age, sex, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization.

CONCLUSION: In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.

}, keywords = {Aged, Cohort Studies, Female, Gait, Geriatric Assessment, Humans, Life Expectancy, Male, Survival Analysis, United States}, issn = {1538-3598}, doi = {10.1001/jama.2010.1923}, author = {Studenski, Stephanie and Perera, Subashan and Patel, Kushang and Rosano, Caterina and Faulkner, Kimberly and Inzitari, Marco and Brach, Jennifer and Chandler, Julie and Cawthon, Peggy and Connor, Elizabeth Barrett and Nevitt, Michael and Visser, Marjolein and Kritchevsky, Stephen and Badinelli, Stefania and Harris, Tamara and Newman, Anne B and Cauley, Jane and Ferrucci, Luigi and Guralnik, Jack} } @article {7131, title = {Digit Symbol Substitution test and future clinical and subclinical disorders of cognition, mobility and mood in older adults.}, journal = {Age Ageing}, volume = {45}, year = {2016}, month = {2016 Sep}, pages = {688-95}, abstract = {

OBJECTIVE: to examine whether psychomotor speed predicts individual and combined disorders in cognition, mobility and mood and if white matter hyperintensities explain these associations.

DESIGN AND SETTING: longitudinal; Cardiovascular Health Study.

SUBJECTS: 5,888 participants (57.6\% women, 15.7\% black, 75.1 (5.5), mean years (SD)).

METHODS: psychomotor speed (Digit Symbol Substitution Test (DSST)) and small vessel disease (white matter hyperintensities (WMH)) were measured in 1992-94. Global cognition (Modified Mini-Mental State (3MS) examination), mobility (gait speed (GS)) and mood (Center for Epidemiologic Studies Depression (CES-D) scale) were measured annually over 5 years and classified as clinical, subclinical or no disorders based on established values (3MS: 80 and 85 points; GS: 0.6 and 1.0 m/s; CES-D: 10 and 5 points). Analyses were adjusted for demographics, baseline status, education, diabetes, hypertension, ankle-arm index.

RESULTS: among those with no disorder in cognition, mobility and mood (N~=~619) in 1992-94, being in the lowest DSST quartile compared to the highest was associated with nearly twice the odds of developing 1+ clinical or subclinical disorders (N~=~413) during follow-up. Associations were stronger for incident clinical disorders in cognition (OR: 8.44, p~<~0.01) or mobility (OR: 9.09, p~<~0.05) than for mood (OR: 1.88, p~<~0.10). Results were similar after adjustment for WMH.

CONCLUSIONS: slower psychomotor speed may serve as a biomarker of risk of clinical disorders of cognition, mobility and mood. While in part attributable to vascular brain disease, other potentially modifiable contributors may be present. Further studying the causes of psychomotor slowing with ageing might provide novel insights into age-related brain disorders.

}, issn = {1468-2834}, doi = {10.1093/ageing/afw116}, author = {Rosano, Caterina and Perera, Subashan and Inzitari, Marco and Newman, Anne B and Longstreth, William T and Studenski, Stephanie} } @article {8630, title = {Catechol-O-Methyltransferase Genotype, Frailty, and Gait Speed in a Biracial Cohort of Older Adults.}, journal = {J Am Geriatr Soc}, year = {2020}, month = {2020 Oct 12}, abstract = {

OBJECTIVE: To examine whether the association between dopamine-related genotype and gait speed differs according to frailty status or race.

DESIGN: Cross-sectional population-based study (Cardiovascular Health Study).

SETTING: Multicenter study, four U.S. sites.

PARTICIPANTS: Volunteer community-dwelling adults aged 65 years and older, without evidence of Parkinson{\textquoteright}s disease (N = 3,744; 71 years; 82\% White; 39\% male).

MEASUREMENTS: Gait speed (usual pace; m/s), physical frailty (Fried definition), and genetic polymorphism of catechol-O-methyltransferase (COMT; rs4680), an enzyme regulating tonic brain dopamine levels, were assessed. Interaction of COMT by frailty and by race predicting gait speed were tested, and, if significant, analyses were stratified. Multivariable regression models of COMT predicting gait speed were adjusted for demographics and locomotor risk factors. Sensitivity analyses were repeated, stratified by clinical cutoffs of gait speed (0.6 and 1.0 m/s) instead of frailty status.

RESULTS: The interaction of COMT by frailty and COMT by race were P = .02 and P = .01, respectively. Compared with Met/Met (higher dopaminergic signaling), the Val/Val group (lower dopaminergic signaling) walked marginally more slowly in the full cohort (0.87 vs 0.89 m/s; P = .2). Gait speed differences were significant for frail (n = 220; 0.55 vs 0.63 m/s; P = .03), but not for prefrail (n = 1,691; 0.81 vs 0.81 m/s; P = .9) or nonfrail (n = 1,833; 0.98 vs 0.97 m/s; P = .7); results were similar in fully adjusted models. Among frail, associations were similar for Whites and Blacks, with statistical significance for Whites only. Associations stratified by clinical cutoffs of gait speed were not significant.

CONCLUSION: The association of dopamine-related genotype with gait speed is stronger among adults with frailty compared with those without frailty. The potential effects of dopaminergic signaling on preserving physical function in biracial cohorts of frail adults should be further examined.

}, issn = {1532-5415}, doi = {10.1111/jgs.16842}, author = {Mance, Shannon and Rosso, Andrea and Bis, Joshua and Studenski, Stephanie and Bohnen, Nico and Rosano, Caterina} }