Measuring higher level physical function in well-functioning older adults: expanding familiar approaches in the Health ABC study

Lean Body Mass Associated with Upper Body Strength in Healthy Older Adults While Higher Body Fat Limits Lower Extremity Performance and Endurance

Impaired strength adversely influences an older person’s ability to perform activities of daily living. A cross-sectional study of 117 independently living men and women (age = 73.4 ± 9.4 year; body mass index (BMI) = 27.6 ± 4.8 kg/m²) aimed to assess the association between body composition and: (1) upper body strength (handgrip strength, HGS); (2) lower extremity performance (timed up and go (TUG) and sit to stand test (STS)); and (3) endurance (6-minute walk (SMWT). Body composition (% fat; lean body mass (LBM)) was assessed using bioelectrical impedance. Habitual physical activity was measured using the Minnesota Leisure Time Physical Activity Questionnaire (MLTPA) and dietary macronutrient intake, assessed using 24 h recalls and 3-day food records. Regression analyses included the covariates, protein intake (g/kg), MLTPA, age and sex. For natural logarithm (Ln) of right HGS, LBM (p < 0.001) and % body fat (p < 0.005) were significant (r² = 46.5%; p < 0.000). For left LnHGS, LBM (p < 0.000), age (p = 0.036), protein intake (p = 0.015) and LnMLTPA (p = 0.015) were significant (r² = 0.535; p < 0.000). For SMW, % body fat, age and LnMLTPA were significant (r² = 0.346; p < 0.000). For STS, % body fat and age were significant (r² = 0.251; p < 0.000). LBM is a strong predictor of upper body strength while higher % body fat and lower physical activity are associated with poorer outcomes on tests of lower extremity performance.

Association between saccular function and gait speed: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To investigate whether otolith function (saccular and utricular) is associated with walking performance.

STUDY DESIGN

Cross-sectional analysis of observational data collected in the Baltimore Longitudinal Study of Aging.

SETTING

National Institute on Aging Intramural Research Program Clinical Research Unit at Harbor Hospital, Baltimore, Maryland.

PATIENTS

Community-dwelling participants.

INTERVENTION(S)

Cervical and ocular vestibular evoked myogenic potentials (VEMPs) were used to assess saccular and utricular function, respectively.

MAIN OUTCOME MEASURE(S)

Cervical and ocular VEMP latency and amplitude responses and usual, rapid, and narrow (20 cm) gait speed assessed over a 6-m course.

RESULTS

In 314 participants (mean age, 73.1 yr; range, 26-96 yr), cervical VEMP amplitude mediated the association between age and gait speed-particularly narrow walk speed-in both men and women. Cervical VEMP latency had an independent association with gait speed in age-, height-, and weight-adjusted analyses, although the direction of the association differed by sex. Greater cervical VEMP latency was associated with slower usual, rapid, and narrow gait speed in women but faster rapid gait speed in men. Neither the amplitude nor latency of ocular VEMP was associated with gait speed in men or women.

CONCLUSION

These findings suggest that age-related slowing of gait speed is in part mediated by the decreased magnitude of saccular response associated with age. The sex-related differential association between saccular response latency and gait speed requires further study.

INTERSECTING SELF-REPORTED MOBILITY AND GAIT SPEED TO CREATEA MULTI-DIMENSIONAL MEASURE OF AMBULATION: THE "AMBULATION SPEED-ENDURANCE" (ASE) TYPOLOGY

BACKGROUND

Assessing mobility through readily available and affordable protocols may help advance public health by providing early detection and implementing intervention therapies aimed at mitigating the progression from physiological vitality to disability at older ages. Until now, little attention has been given to how self-reported mobility (SRM) and gait speed can be combined in a categorization scheme.

OBJECTIVES

The specific aim of this report is to introduce the Ambulation Speed-Endurance (ASE) Typology to the literature-a classification system that intersects SRM and gait speed to create a multi-dimensional measure of ambulation.

DESIGN

Cross-sectional.

SETTING

Community-dwelling older adults in the United States.

PARTICIPANTS

Evidence is provided from the National Health and Aging Trends Study (NHATS) that community-dwelling older adults (n=5,403) may be found in each of the ASE Typologies. The discussion is complimented by investigating the cross-sectional predictors of a "Discrepancy Score" (measure of gap between speed and endurance) amongst those with gait speeds < 0.99 m/sec (n=4,521).

RESULTS

Multivariable linear regression results indicate level of severity in speed-endurance discrepancy is higher amongst: non-Latino-Blacks (β=0.48); Latinos (β=0.42); older ages; and lower educated. Models also show that severity in speed-endurance discrepancy is lower amongst: females (β=-0.38); those with higher body mass index; with more chronic health conditions; and poorer self-rated health.

CONCLUSION

Research should continue to investigate how to optimize SRM.

Body Mass Index Trajectories in Relation to Change in Lean Mass and Physical Function: The Health, Aging and Body Composition Study

OBJECTIVES

To examine body mass index (BMI) trajectories with change in lean mass and physical function in old age.

DESIGN

Prospective cohort study.

SETTING

Health, Aging and Body Composition Study.

PARTICIPANTS

Black and white men (n = 482) and women (n = 516) aged 73.1 ± 2.7 and initially free of disability.

MEASUREMENTS

A group-based trajectory model was used to determine BMI trajectories, the path a person's BMI followed over 9 years. Lean mass, gait speed, grip strength, and knee extension strength were assessed at baseline and after 9 years, and relative changes were calculated. Multivariable linear regression was used to determine associations between trajectories and relative change in lean mass and physical function.

RESULTS

Four BMI trajectories were identified for men and four for women. Although all demonstrated a decline in BMI, the rate of decline differed according to trajectory for women only. Men in Trajectory 4 (mean BMI at baseline 33.9 ± 2.3 kg/m(2) ) declined more than those in Trajectory 1 (mean BMI at baseline 22.9 ± 1.6 kg/m(2) ) in gait speed (-9.91%, 95% confidence interval (CI) = -15.15% to -4.67%) and leg strength (-8.63%, 95% CI = -15.62% to -1.64%). Women in Trajectory 4 (mean BMI at baseline 34.9 ± 3.0 kg/m(2) ) had greater losses than those in Trajectory 1 (mean BMI at baseline 20.5 ± 1.6 kg/m(2) ) in lean mass in the arms (-3.19%, 95% CI = -6.16% to -0.23%). No other associations were observed.

CONCLUSION

Obese men had the highest risk of decline in physical function despite similar weight loss between trajectories, whereas overweight and obese women who lost the most weight had the greatest risk of lean mass loss. The weight at which a person enters old age is informative for predicting loss in lean mass and physical function, illustrating the importance of monitoring weight.

Blood-cell bioenergetics are associated with physical function and inflammation in overweight/obese older adults

BACKGROUND

Physical function and strength decline with age and lead to limited mobility and independence in older adults. Alterations in mitochondrial function are thought to underlie numerous age-related changes, including declining physical ability. Recent studies suggest that systemic changes in bioenergetic capacity may be reported by analyzing mitochondrial function in circulating cells. The objective of this study was to determine whether the bioenergetic capacity of peripheral blood mononuclear cells (PBMCs) is related to differences in physical function among older, overweight/obese, adults. To address this, we tested the hypothesis that greater PBMC respirometric capacity would be associated with better physical function, muscular strength, leg lean mass, and muscle quality. Furthermore, we tested whether the respirometric capacity of PBMCs is related to cellular composition and inflammatory status reported by interleukin-6 (IL-6).

METHODS

Fasted PBMC respiration (pmol/min/500,000 cells), expanded short physical performance battery (Ex-SPPB), peak knee extensor (KE) strength (Nm), grip strength (kg), leg lean mass (kg, via dual energy X-ray absorptiometry [DXA]), muscle quality (Nm/kg), and plasma IL-6 (pg/mL) were analyzed in 15 well-functioning, community-dwelling, sedentary overweight/obese older men (n=9) and women (n=6) aged 65 to 78 (mean 68.3 ± 3.5 years). Pearson and partial correlations were calculated to determine associations between PBMC respiration and these variables.

RESULTS

Higher maximal respiration of PBMCs was associated with better Ex-SPPB (r=0.58, p=0.02), greater KE strength (r=0.60, p=0.02), greater grip strength (r=0.52, p=0.05) and lower IL-6 (r=-0.58, p=0.04). Higher spare respiratory capacity was associated with better Ex-SPPB (r=0.59, p=0.02), greater KE strength (r=0.60, p=0.02), greater grip strength (r=0.54, p=0.04), greater leg muscle quality (r=0.56, p=0.04), and lower IL-6 (r=-0.55, p=0.05). Monocyte and lymphocyte counts were not related to PBMC respiratory capacity.

CONCLUSIONS

Our results indicate that respirometric profiles of readily obtainable blood cells are associated with physical function and strength. Future studies should be undertaken in order to determine whether blood-based bioenergetic profiling can provide an objective index of systemic mitochondrial health.

Persistent Pain Among Older Adults Discharged Home From the Emergency Department After Motor Vehicle Crash: A Prospective Cohort Study

STUDY OBJECTIVE

Motor vehicle crashes are the second most common form of trauma among older adults. We seek to describe the incidence, risk factors, and consequences of persistent pain among older adults evaluated in the emergency department (ED) after a motor vehicle crash.

METHODS

We conducted a prospective longitudinal study of patients aged 65 years or older who presented to one of 8 EDs after motor vehicle crash between June 2011 and June 2014 and were discharged home after evaluation. ED evaluation was done through in-person interview; follow-up data were obtained through mail-in survey or telephone call. Pain severity (0 to 10 scale) overall and for 15 parts of the body were assessed at each follow-up point. Principal component analysis was used to assess the dimensionality of the locations of pain data. Participants reporting pain severity greater than or equal to 4 attributed to the motor vehicle crash at 6 months were defined as having persistent pain.

RESULTS

Of the 161 participants, 72% reported moderate to severe pain at the ED evaluation. At 6 months, 26% of participants reported moderate to severe motor vehicle crash-related pain. ED characteristics associated with persistent pain included acute pain severity; pain located in the head, neck, and jaw or lower back and legs; poor self-rated health; less formal education; pre-motor vehicle crash depressive symptoms; and patient's expected time to physical recovery more than 30 days. Compared with individuals without persistent pain, those with persistent pain were substantially more likely at 6-month follow-up to have also experienced a decline in their capacity for physical function (73% versus 36%; difference=37%; 95% confidence interval [CI] 19% to 52%), a new difficulty with activities of daily living (42% versus 17%; difference=26%; 95% CI 10% to 43%), a 1-point or more reduction in overall self-rated health on a 5-point scale (54% versus 30%; difference=24%; 95% CI 6% to 41%), and a change in their living situation to obtain additional help (23% versus 8%; difference=15%; 95% CI 2% to 31%).

CONCLUSION

Among older adults discharged home from the ED post-evaluation after a motor vehicle crash, persistent pain is common and frequently associated with functional decline and disability.

Association Between Hearing Impairment and Risk of Hospitalization in Older Adults

OBJECTIVES

To determine the association between hearing impairment (HI) and risk and duration of hospitalization in community-dwelling older adults in the United States.

DESIGN

Prospective observational study.

SETTING

Health, Aging and Body Composition Study.

PARTICIPANTS

Well-functioning community-dwelling white and black Medicare beneficiaries aged 70 to 79 at study enrollment in 1997-98 were followed for a median of 12 years.

MEASUREMENTS

Incidence, annual rate, and duration of hospitalization were the primary outcomes. Hearing was defined as the pure-tone average (PTA) of hearing thresholds in decibels re: hearing level (dB HL) at octave frequencies from 0.5 to 4.0 kHz. Mild HI was defined as a PTA from 25 to 40 dB HL, and moderate or greater HI was defined as a PTA greater than 40 dB HL.

RESULTS

Of the 2,148 participants included in the analysis, 1,801 (83.5%) experienced one or more hospitalizations, with 7,007 adjudicated hospitalization events occurring during the study period. Eight hundred eighty-two (41.1%) participants had normal hearing, 818 (38.1%) had mild HI, and 448 (20.9%) had moderate or greater HI. After adjusting for demographic characteristics and cardiovascular comorbidities, persons with mild HI experienced a 16% (hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 1.04-1.29) greater risk of incident hospitalization and a 17% (incidence rate ratio (IRR) = 1.17, 95% CI = 1.04-1.32) greater annual rate of hospitalization, and those with moderate or greater HI experienced a 21% (HR = 1.21, 95% CI = 1.06-1.38) greater risk of incident hospitalization and a 19% (IRR = 1.19, 95% CI = 1.04-1.38) greater annual rate of hospitalization than persons with normal hearing. There was no significant association between HI and mean duration of hospitalization.

CONCLUSION

Hearing-impaired older adults experience a greater incidence and annual rate of hospitalization than those with normal hearing. Investigating whether rehabilitative therapies could affect the risk of hospitalization in older adults requires further study.

Physical Activity and Change in Long Distance Corridor Walk Performance in the Health, Aging, and Body Composition Study

OBJECTIVES

To examine the prospective relationship between self-reported physical activity and aerobic fitness in the Health, Aging, and Body Composition Study (Health ABC) using the Long Distance Corridor Walk (LDCW).

DESIGN

Cohort study with 7 years of follow-up.

SETTING

Two U.S. clinical sites.

PARTICIPANTS

Community-dwelling older adults enrolled in Health ABC (N = 3,075, aged 70-79, 52% female, 42% black) with no self-reported difficulty walking one-quarter of a mile or climbing 10 steps.

MEASUREMENTS

Participants were classified based on a physical activity questionnaire as being inactive (≤1,000 kcal/wk exercise activity, ≤2,719 kcal/wk total physical activity), lifestyle active (≤1,000 kcal/wk exercise activity, >2,719 kcal/wk total physical activity), or exercisers (≥1,000 kcal/wk exercise activity). The LDCW, an endurance walking test (400 m), was administered at Years 1 (baseline), 2, 4, 6, and 8 to assess aerobic fitness.

RESULTS

At baseline, LDCW completion times (adjusted for age and sex) were 351.8 seconds (95% confidence interval (CI) = 346.9-356.8 seconds) for the inactive group, 335.9 seconds (95% CI = 332.7-339.1 seconds) for the lifestyle active group, and 307.7 seconds (95% CI = 303.2-312.3 seconds) for the exerciser group (P < .001). From baseline to Year 8, the inactive group slowed 36.1 seconds (95% CI = 28.4-43.8 seconds), the lifestyle active group slowed 38.1 seconds (95% CI = 33.6-42.4 seconds), and the exerciser group slowed 40.8 seconds (95% CI = 35.2-46.5 seconds), and did not differ significantly between groups. In linear mixed-effects models, the rate of change in LDCW time did not differ between the groups, although exercisers consistently had the fastest completion times (P < .001 for all pairwise comparisons).

CONCLUSION

Decline in LDCW time occurred regardless of baseline activity, although exercisers maintained higher aerobic fitness, which may delay reaching a critically low threshold of aerobic fitness at which independence is impaired.

TV Watching, but Not Physical Activity, Is Associated With Change in Kidney Function in Older Adults

BACKGROUND

Physical activity (PA) may play a role in preserving kidney health. The purpose of this study was to determine if PA and sedentary behavior are associated with incident chronic kidney disease (CKD) and change in kidney function in older adults.

METHODS

The Health, Aging, and Body Composition study is a prospective cohort of 3075 well-functioning older adults. PA and television watching was measured by self-report, and serum cystatin C was used to estimate glomerular filtration rate (eGFR). CKD was defined as an eGFR <60 ml/min/1.73 m(2). Rapid kidney function decline was defined as an annual loss in eGFR of >3 ml/min/1.73 m(2). Discrete survival analysis was used to determine if baseline PA and television watching were related to 10-year cumulative incidence of CKD and rapid decline in kidney function.

RESULTS

Individuals who reported watching television >3 hours/day had a higher risk of incident CKD (HR 1.34; 95% CI, 1.09-1.65) and experiencing a rapid decline in kidney function (HR 1.26; 95% CI, 1.05-1.52) compared with individuals who watched television <2 hours/day. PA was not related to either outcome.

CONCLUSIONS

High levels of television watching are associated with declining kidney function; the mechanisms that underlie this association need further study.

The Virtual Short Physical Performance Battery

BACKGROUND

Performance-based and self-report instruments of physical function are frequently used and provide complementary information. Identifying older adults with a mismatch between actual and perceived function has utility in clinical settings and in the design of interventions. Using novel, video-animated technology, the objective of this study was to develop a self-report measure that parallels the domains of objective physical function assessed by the Short Physical Performance Battery (SPPB)-the virtual SPPB (vSPPB).

METHODS

The SPPB, vSPPB, the self-report Pepper Assessment Tool for Disability, the Mobility Assessment Tool-short form, and a 400-m walk test were administered to 110 older adults (mean age = 80.6±5.2 years). One-week test-retest reliability of the vSPPB was examined in 30 participants.

RESULTS

The total SPPB (mean [±SD] = 7.7±2.8) and vSPPB (7.7±3.2) scores were virtually identical, yet moderately correlated (r = .601, p < .05). The component scores of the SPPB and vSPPB were also moderately correlated (all p values <.01). The vSPPB (intraclass correlation = .963, p < .05) was reliable; however, individuals with the lowest function overestimated their overall lower extremity function while participants of all functional levels overestimated their ability on chair stands, but accurately perceived their usual gait speed.

CONCLUSION

In spite of the similarity between the SPPB and vSPPB, the moderate strength of the association between the two suggests that they offer unique perspectives on an older adult's physical function.

Improvements in Functional Exercise Capacity after a Residential Behavioural Change, Diet and Fitness Program for Obese Adults

BACKGROUND AND PURPOSE

Obese adults are at an increased risk for mobility-related problems. National guidelines recommend calorie restrictions and exercise for obese adults as a means to improve functional fitness capacity and to increase mobility. Yet, lifestyle weight loss interventions often fail to measure fitness changes. The aim of this study was to assess whether a 1-month, intensive behavioural change, diet and fitness intervention for overweight and obese adults would result in statistically significant and clinically meaningful changes in functional exercise.

METHODS

A pre-post test design was used in this study. Seventy-two participants (40 women, 32 men; mean baseline body mass index (BMI) = 42.6 + 9.0; mean age = 45.8 + 16.8) completed a modified 6-minute walk test (6MWT), performed on a treadmill, at baseline and at end of treatment.

RESULTS

Significant improvements included decreased BMI (2.7 + 1.7 kg m(-2) , p < 0.001) and increased 6MWT distance (66.4 + 73.0 m, p < 0.001). The 6MWT improved by 66 m on average, a reported clinically meaningful difference. Greater improvements in the 6MWT were significantly correlated with greater weight loss and BMI reduction.

DISCUSSION

Our findings suggest that rehabilitation beyond weight loss may be derived from participation in a brief, intensive behavioural change, diet and fitness programme. Physiotherapists are in a prime position to address the physical and motivational challenges participants face while living with severe obesity: targeting functional exercise capacity is one key strategy for addressing immobility associated with obesity. Copyright © 2015 John Wiley & Sons, Ltd.

[Effects of a physical activity program using exergame with elderly women]

PURPOSE

This study was done to investigate the motivational, physical and affective benefits of exergaming in community dwelling older adult women.

METHODS

The research design was a nonequivalent control group pre-test and post-test design. Sixty-one older adult women over the age of 65 were recruited from 6 community senior centers to participate in the 8 week exercise intervention or control group. Six centers were divided into one of three groups: exergame, qigong exercise, or control. The exergame and the qigong exercise group received 16 sessions, scheduled twice a week, with each session lasting 50 minutes. Test measures were completed before and after the 8 week intervention period for all participants. Measures included: Grip strength, chair stand, 6 m walking, balance, geriatric depression scale, vitality and intrinsic motivation.

RESULTS

There were significant improvements in the exergame and qigong exercise group for grip strength, chair stand, 6m walking, balance, vitality and intrinsic motivation at the end the 8-week program compared with the control group.

CONCLUSION

The exergame could be an effective alternative for older adult women to group exercise classes.

Functional impairment, disability, and frailty in adults aging with HIV-infection

The integration of antiretroviral therapy (i.e., ART) into HIV care has dramatically extended the life expectancy of those living with HIV. However, in comparison to similar HIV-uninfected populations, HIV-infected persons experience an excess of morbidity and mortality with an early onset of aging complications including neurocognitive decline, osteoporosis, impaired physical function, frailty, and falls. Recent consensus guidelines encourage clinicians and researchers to consider functional impairment of HIV-infected adults as a measure to understand the impact of aging across a range of abilities. Despite the importance of assessing function in persons aging with HIV infection, a lack of consistent terminology and standardization of assessment tools has limited the application of functional assessments in clinical or research settings. Herein, we distinguish between different approaches used to assess function, describe what is known about function in the aging HIV population, and consider directions for future research.

Objective measures of physical activity, white matter integrity and cognitive status in adults over age 80

The neuroprotective effects of physical activity (PA) are consistently shown in older adults, but the neural substrates, particularly in white matter (WM), are understudied, especially in very old adults with the fastest growth rate and the highest risk of dementia. This study quantified the association between PA and WM integrity in adults over 80. The moderating effects of cardiometabolic conditions, physical functional limitations and WM hyperintensities were also examined, as they can affect PA and brain integrity. Fractional anisotropy (FA) from normal-appearing WM via diffusion tensor imaging and WM hyperintensities were obtained in 90 participants (mean age = 87.4, 51.1% female, 55.6% white) with concurrent objective measures of steps, active energy expenditure (AEE in kcal), duration (min), and intensity (metabolic equivalents, METs) via SenseWear Armband. Clinical adjudication of cognitive status, prevalence of stroke and diabetes, systolic blood pressure, and gait speed were assessed at time of neuroimaging. Participants were on average sedentary (mean ± SD/day: 1766 ± 1345 steps, 202 ± 311 kcal, 211 ± 39 min, 1.8 ± 1.1 METs). Higher steps, AEE and duration, but not intensity, were significantly associated with higher FA. Associations were localized in frontal and temporal areas. Moderating effects of cardiometabolic conditions, physical functional limitations, and WM hyperintensities were not significant. Neither FA nor PA was related to cognitive status. Older adults with a sedentary lifestyle and a wide range of cardiometabolic conditions and physical functional limitations, displayed higher WM integrity in relation to higher PA. Studies of very old adults to quantify the role of PA in reducing dementia burden via WM integrity are warranted.

Development and validation of risk index for cognitive decline using blood-derived markers

OBJECTIVE

We sought to develop and validate a risk index for prospective cognitive decline in older adults based on blood-derived markers.

METHODS

The index was based on 8 markers that have been previously associated with cognitive aging: APOE genotype, plasma β-amyloid 42/40 ratio, telomere length, cystatin C, glucose, C-reactive protein, interleukin-6, and albumin. The outcome was person-specific cognitive slopes (Modified Mini-Mental State Examination) from 11 years of follow-up. A total of 1,445 older adults comprised the development sample. An index based on dichotomized markers was divided into low-, medium-, and high-risk categories; the risk categories were validated with the remaining sample (n = 739) using linear regression. Amyloid was measured on a subsample (n = 865) and was included only in a secondary index.

RESULTS

The risk categories showed significant differences from each other and were predictive of prospective cognitive decline in the validation sample, even after adjustment for age and baseline cognitive score: the low-risk group (24.8%) declined 0.32 points/y (95% confidence interval [CI]: -0.46, -0.19), the medium-risk group (58.7%) declined 0.55 points/y (95% CI: -0.65, 0.45), and the high-risk group (16.6%) declined 0.69 points/y (95% CI: -0.85, -0.54). Using the secondary index, which included β-amyloid 42/40 (validation n = 279), the low-risk group (26.9%) declined 0.20 points/y (95% CI: -0.42, 0.01), the medium-risk group (61.3%) declined 0.55 points/y (95% CI: -0.72, -0.38), and the high-risk group (11.8%) declined 0.83 points/y (95% CI: -1.14, -0.51).

CONCLUSIONS

A risk index based on 8 blood-based markers was modestly able to predict cognitive decline over an 11-year follow-up. Further validation in other cohorts is necessary.

Statin use and decline in gait speed in community-dwelling older adults

OBJECTIVES

To examine the association between statin use and objectively assessed decline in gait speed in community-dwelling older adults.

DESIGN

Longitudinal cohort study.

SETTING

Health, Aging and Body Composition (Health ABC) Study.

PARTICIPANTS

Two thousand five participants aged 70-79 at baseline with medication and gait speed data at 1998-99, 1999-2000, 2001-02, and 2002-03.

MEASUREMENTS

The independent variables were any statin use and their standardized daily doses (low, moderate, high) and lipophilicity. The primary outcome measure was decline in gait speed of 0.1 m/s or more in the following year of statin use. Multivariable generalized estimating equations were used, adjusting for demographic characteristics, health-related behaviors, health status, and access to health care.

RESULTS

Statin use increased from 16.2% in 1998-99 to 25.6% in 2002-03. The overall proportions of those with decline in gait speed of 0.1 m/s or more increased from 22.2% in 1998 to 23.9% in 2003. Statin use was not associated with decline in gait speed of 0.1 m/s or more (adjusted odds ratio (AOR) = 0.90, 95% confidence interval (CI) = 0.77-1.06). Similar nonsignificant trends were also seen with the use of hydrophilic or lipophilic statins. Users of low-dose statins were found to have a 22% lower risk of decline in gait speed than nonusers (AOR = 0.78, 95% CI = 0.61-0.99), which was mainly driven by the results from 1999-2000 follow-up.

CONCLUSION

These results suggest that statin use did not increase decline in gait speed in community-dwelling older adults.

A long-term intensive lifestyle intervention and physical function: the look AHEAD Movement and Memory Study

OBJECTIVE

To assess the long-term effects of an intensive lifestyle intervention on physical function using a randomized post-test design in the Look AHEAD trial.

METHODS

Overweight and obese (BMI ≥ 25 kg m(-2)) middle-aged and older adults (aged 45-76 years at enrollment) with type 2 diabetes (n = 964) at four clinics in Look AHEAD, a trial evaluating an intensive lifestyle intervention (ILI) designed to achieve weight loss through caloric restriction and increased physical activity compared to diabetes support and education (DSE), underwent standardized assessments of performance-based physical function including an expanded short physical performance battery (SPPBexp ), 20-m and 400-m walk, and grip and knee extensor strength 8 years post-randomization, during the trial's weight maintenance phase.

RESULTS

Eight years post-randomization, individuals randomized to ILI had better SPPBexp scores [adjusted mean (SE) difference: 0.055 (0.022), P = 0.01] and faster 20-m and 400-m walk speeds [0.032 (0.012) m s(-1) , P = 0.01, and 0.025 (0.011) m s(-1) , P = 0.02, respectively] compared to those randomized to DSE. Achieved weight loss greatly attenuated the group differences in physical function, and the intervention effect was no longer significant.

CONCLUSIONS

An intensive lifestyle intervention has long-term benefits for mobility function in overweight and obese middle-aged and older individuals with type 2 diabetes.

Visual impairment and incident mobility limitations: the health, aging and body composition study

OBJECTIVES

To examine the association between multiple measures of visual impairment (VI) and incident mobility limitations in older adults.

DESIGN

Prospective observational cohort study.

SETTING

Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Health, Aging and Body Composition study participants aged 70 to 79 without mobility limitations at the Year 3 visit (N = 1,862).

MEASUREMENTS

Vision was measured at the Year 3 visit, and VI was defined as distance visual acuity (VA) worse than 20/40, contrast sensitivity (CS) less than 1.55 log Contrast, and stereoacuity (SA) greater than 85 arcsec. Incident persistent walking and stair climbing limitation was defined as two consecutive 6-month reports of any difficulty walking one-quarter of a mile or walking up 10 steps after 1, 3, and 5 years of follow-up.

RESULTS

At Year 3 (baseline for these analyses), 7.4% had impaired VA, 27.2% had impaired CS, and 29.2% had impaired SA. At all follow-up times, the incidence of walking and stair climbing limitations was higher in participants with VA, CS, or SA impairment. After 5 years, impaired CS and SA were independently associated with greater risk of walking limitation (hazard ratio (HR)CS = 1.3, 95% confidence interval (CI) = 1.1-1.7; HRSA = 1.3, 95% CI = 1.1-1.6) and stair climbing limitation (HRCS = 1.4, 95% CI = 1.1-1.8; HRSA = 1.3, 95% CI=1.1-1.7). Having impaired CS and SA was associated with greater risk of mobility limitations (HRwalking limitations = 2.0, 95% CI = 1.6-2.5; HRstair limitation = 2.1, 95% CI = 1.6-2.8).

CONCLUSION

Multiple aspects of VI may contribute to mobility limitations in older adults. Addressing more than one component of vision may be needed to reduce the effect of vision impairment on functional decline.

Predictive validity and responsiveness of patient-reported and performance-based measures of function in the Boston RISE study

BACKGROUND

Patient-reported and performance-based measures (PBMs) are commonly used to measure physical function in studies of older adults. Selection of appropriate measures to address specific research questions is complex and requires knowledge of relevant psychometric properties. The aim of this study was to examine the predictive validity for adverse outcomes and responsiveness of a widely used patient-reported measure, the Late-Life Function and Disability Instrument (LLFDI), compared with PBMs.

METHODS

We analyzed 2 years of follow-up data from Boston RISE, a cohort study of 430 primary care patients aged ≥65 years. Logistic and linear regression models were used to examine predictive validity for adverse outcomes and effect size and minimal detectable change scores were computed to examine responsiveness. Performance-based functional measures included the Short Physical Performance Battery, 400-m walk, gait speed, and stair-climb power test.

RESULTS

The LLFDI and PBMs showed high predictive validity for poor self-rated health, hospitalizations, and disability. The LLFDI function scale was the only measure that predicted falls. Absolute effect size estimates ranged from 0.54 to 0.64 for the LLFDI and from 0.34 to 0.63 for the PBMs. From baseline to 2 years, the percentage of participants with a change ≥ minimal detectable change was greatest for the LLFDI scales (46-59%) followed by the Short Physical Performance Battery (44%), gait speed (35%), 400-m walk (17%), and stair-climb power test (9%).

CONCLUSIONS

The patient-reported LLFDI showed comparable psychometric properties to PBMs. Our findings support the use of the LLFDI as a primary outcome in gerontological research.

Association of hearing impairment with declines in physical functioning and the risk of disability in older adults

BACKGROUND

Identifying factors associated with functional declines in older adults is important given the aging of the population. We investigated if hearing impairment is independently associated with objectively measured declines in physical functioning in a community-based sample of older adults.

METHODS

Prospective observational study of 2,190 individuals from the Health, Aging, and Body Composition study. Participants were followed annually for up to 11 visits. Hearing was measured with pure-tone audiometry. Physical functioning and gait speed were measured with the Short Physical Performance Battery (SPPB). Incident disability and requirement for nursing care were assessed semiannually through self-report.

RESULTS

In a mixed-effects model, greater hearing impairment was associated with poorer physical functioning. At both Visit 1 and Visit 11, SPPB scores were lower in individuals with mild (10.14 [95% CI 10.04-10.25], p < .01; 7.35 [95% CI 7.12-7.58], p < .05) and moderate or greater hearing impairment (10.04 [95% CI 9.90-10.19], p < .01; 7.00 [95% CI 6.69-7.32], p < .01) than scores in normal hearing individuals (10.36 [95% CI 10.26-10.46]; 7.71 [95% CI 7.49-7.92]). We observed that women with moderate or greater hearing impairment had a 31% increased risk of incident disability (Hazard ratio [HR] =1.31 [95% CI 1.08-1.60], p < .01) and a 31% increased risk of incident nursing care requirement (HR = 1.31 [95% CI 1.05-1.62], p = .02) compared to women with normal hearing.

CONCLUSIONS

Hearing impairment is independently associated with poorer objective physical functioning in older adults, and a 31% increased risk for incident disability and need for nursing care in women.

Declines in inflammation predict greater white matter microstructure in older adults

Protracted systemic inflammation has been associated with adverse effects on cognition and brain structure and may accelerate neurodegenerative disease processes; however, it is less clear whether changes in inflammation are associated with brain structure. We studied 276 black and white older adults (mean age = 83 years at time of imaging) enrolled in a prospective study of aging. Inflammation (measured with c-reactive protein, CRP) was assessed repeatedly over 6 years (i.e., year 2, 4, 6, and 8). Brain magnetic resonance imaging (MRIs) were obtained at years 10-11 with diffusion tensor imaging; regions of interest included late-myelinating areas vulnerable to aging, including frontal-parietal (superior longitudinal fasciculus [SLF]-dorsal) and temporal (SLF-temporal; uncinate) white matter tracts. Mean CRP values significantly declined (t = -5.54, p < 0.0001) over 6 years, and subject-specific slopes (best linear unbiased predictors of slopes) all showed a decline (mean = -0.57, standard deviation = 0.53) for our participant sample. More than 50% of study participants were still in the moderate to high cardiovascular risk range based on CRP values at year 8. After controlling for demographics, vascular risk factors and MRI white matter hyperintensities, larger decreases in CRP values over time were significantly associated with higher fractional anisotropy in the SLF-dorsal (beta = -0.0052, standard error [SE] = 0.003; 95% confidence interval [CI] = -0.0103 to -0.0025, p = 0.04), SLF-temporal (beta = -0.0109, SE = 0.004; 95% CI = -0.0189 to -0.0029, p = 0.008), and uncinate (beta = -0.0067, SE = 0.003; 95% CI = -0.0132 to -0.0001, p = 0.05) fasciculi. Results suggest that in a prospective cohort of older individuals, faster declines in inflammation over time are related to indicators of white matter health, even after accounting for vascular risk factors.

Effect of age on in vivo oxidative capacity in two locomotory muscles of the leg

To determine the effects of age and sex on in vivo mitochondrial function of distinct locomotory muscles, the tibialis anterior (TA) and medial gastrocnemius (MG), of young (Y; 24 ± 3 years) and older (O; 69 ± 4) men (M) and women (W) of similar overall physical activity (PA) was compared. In vivo mitochondrial function was measured using phosphorus magnetic resonance spectroscopy, and PA and physical function were measured in all subjects. Overall PA was similar among the groups, although O (n = 17) had fewer daily minutes of moderate-to-vigorous PA (p = 0.001), and slowed physical function (p < 0.05 for all variables), compared with Y (n = 17). In TA, oxidative capacity (V max; mM s(-1)) was higher in O than Y (p < 0.001; Y = 0.90 ± 0.12; O = 1.12 ± 0.18). There was no effect of age in MG (p = 0.5; Y = 0.91 ± 0.17; O = 0.96 ± 0.24), but women had higher oxidative capacity than men (p = 0.007; M = 0.84 ± 0.18; W = 1.03 ± 0.18). In vivo mitochondrial function was preserved in healthy O men and women, despite lower intensity PA and physical function in this group. The extent to which compensatory changes in gait may be responsible for this preservation warrants further investigation. Furthermore, women had higher oxidative capacity in the MG, but not the TA.

Cardiorespiratory fitness and brain diffusion tensor imaging in adults over 80 years of age

A positive association between cardiorespiratory fitness (CRF) and white matter integrity has been consistently reported in older adults. However, it is unknown whether this association exists in adults over 80 with a range of chronic disease conditions and low physical activity participation, which can influence both CRF and brain health. This study examined whether higher CRF was associated with greater microstructural integrity of gray and white matter in areas related to memory and information processing in adults over 80 and examined moderating effects of chronic diseases and physical activity. CRF was measured as time to walk 400 m as quickly as possible with concurrent 3T diffusion tensor imaging in 164 participants (57.1% female, 40.3% black). Fractional anisotropy (FA) was computed for cingulum, uncinate and superior longitudinal fasciculi. Mean diffusivity (MD) was computed for dorsolateral prefrontal cortex, hippocampus, parahippocampus, and entorhinal cortex. Moderating effects were tested using hierarchical regression models. Higher CRF was associated with higher FA in cingulum and lower MD in hippocampus and entorhinal cortex (β, sex-adjusted p: -0.182, 0.019; 0.165, 0.035; and 0.220, 0.006, respectively). Hypertension attenuated the association with MD in entorhinal cortex. Moderating effects of chronic diseases and physical activity in walking and climbing stairs on these associations were not significant. The association of higher CRF with greater microstructural integrity in selected subcortical areas appears robust, even among very old adults with a range of chronic diseases. Intervention studies should investigate whether increasing CRF can preserve memory and information processing by improving microstructure and potential effects of hypertension management.

Association of hearing impairment and mortality in older adults

BACKGROUND

Hearing impairment (HI) is highly prevalent in older adults and is associated with social isolation, depression, and risk of dementia. Whether HI is associated with broader downstream outcomes is unclear. We undertook this study to determine whether audiometric HI is associated with mortality in older adults.

METHODS

Prospective observational data from 1,958 adults ≥70 years of age from the Health, Aging, and Body Composition Study were analyzed using Cox proportional hazards regression. Participants were followed for 8 years after audiometric examination. Mortality was adjudicated by obtaining death certificates. Hearing was defined as the pure-tone average of hearing thresholds in decibels re: hearing level (dB HL) at frequencies from 0.5 to 4kHz. HI was defined as pure-tone average >25 dB HL in the better ear.

RESULTS

Of the 1,146 participants with HI, 492 (42.9%) died compared with 255 (31.4%) of the 812 with normal hearing (odds ratio = 1.64, 95% CI: 1.36-1.98). After adjustment for demographics and cardiovascular risk factors, HI was associated with a 20% increased mortality risk compared with normal hearing (hazard ratio = 1.20, 95% CI: 1.03-1.41). Confirmatory analyses treating HI as a continuous predictor yielded similar results, demonstrating a nonlinear increase in mortality risk with increasing HI (hazard ratio = 1.14, 95% CI: 1.00-1.29 per 10 dB of threshold elevation up to 35 dB HL).

CONCLUSIONS

HI in older adults is associated with increased mortality, independent of demographics and cardiovascular risk factors. Further research is necessary to understand the basis of this association and whether these pathways might be amenable to hearing rehabilitation.

Reconceptualizing balance: attributes associated with balance performance

Balance tests are commonly used to screen for impairments that put older adults at risk for falls. The purpose of this study was to determine the attributes that were associated with balance performance as measured by the Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) balance test. This study was a cross-sectional secondary analysis of baseline data from a longitudinal cohort study, the Boston Rehabilitative Impairment Study of the Elderly (Boston RISE). Boston RISE was performed in an outpatient rehabilitation research center and evaluated Boston area primary care patients aged 65 to 96 (N=364) with self-reported difficulty or task-modification climbing a flight of stairs or walking 1/2 of a mile. The outcome measure was standing balance as measured by the FICSIT-4 balance assessment. Other measures included: self-efficacy, pain, depression, executive function, vision, sensory loss, reaction time, kyphosis, leg range of motion, trunk extensor muscle endurance, leg strength and leg velocity at peak power. Participants were 67% female, had an average age of 76.5 (±7.0) years, an average of 4.1 (±2.0) chronic conditions, and an average FICSIT-4 score of 6.7 (±2.2) out of 9. After adjusting for age and gender, attributes significantly associated with balance performance were falls self-efficacy, trunk extensor muscle endurance, sensory loss, and leg velocity at peak power. FICSIT-4 balance performance is associated with a number of behavioral and physiologic attributes, many of which are amenable to rehabilitative treatment. Our findings support a consideration of balance as multidimensional activity as proposed by the current International Classification of Functioning, Disability, and Health (ICF) model.

Rehabilitation and supportive therapy in elderly patients with Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) very often coexists with cardiovascular, musculoskeletal and metabolic comorbidities. This condition significantly impact on the general health, function, frailty and disability of such patients, and consequently on their prognosis. Indeed, complex and recurrent symptoms of general dysfunction are commonly present and burden on the health status. Symptomatic COPD patients, even with chronic and complex comorbidities or with different degree of severity, may benefit from rehabilitation including exercise and maintenance of physical activity, in order to reducing symptoms and restoring the highest possible level of independent function. This review will focus on the associated and relevant clinical problems of these patients at the onset of disability, methods of assessment and useful non-pharmacological treatments for caring and supporting them.

Battery of behavioral tests in mice that models age-associated changes in human motor function

Motor function in humans can be characterized with tests of locomotion, strength, balance, and endurance. The aim of our project was to establish an analogous test battery to assess motor function in mice. Male C57BL/6 mice were studied at 3 (n = 87), 20 (n = 48) and 26 (n = 43) months of age. Tests assessed locomotion, strength, balance/coordination, and endurance capacity in mice. Motor function was reduced in the older groups of mice for the locomotion, strength, and endurance subdomains (p < 0.001). As indicated with a summary score, motor function declined by 7.4 % from 3 to 20 months and by 13.5 % from 20 to 26 months. Based on comparison with previously published data in humans, the magnitude and relative time course of changes were similar in mice and humans in each subdomain except balance/coordination. Power calculations confirmed that the age-associated differences depicted by several of the individual tests and domain summary scores would be sufficient to assess the efficacy of interventions aimed at prevention or treatment of motor dysfunction with aging. The current study describes a mouse model that characterizes age-associated changes in clinically relevant domains of motor function and indicates that the preclinical model can be used to test strategies to attenuate age-associated declines in motor function.

Are estimates of meaningful decline in mobility performance consistent among clinically important subgroups? (Health ABC study)

BACKGROUND

Meaningful change criteria help determine if function has improved or declined, but their magnitudes may vary across clinically relevant subgroups. We estimate meaningful decline in four common measures of physical performance in subgroups of older adults based on initial performance, demographics, chronic conditions, and health status.

METHODS

We used baseline (Year 1) and Year 4 data from the Health, Aging and Body Composition (Health ABC) study, a well-functioning cohort at baseline of white and black men and women (age 70-79), to evaluate the magnitude of meaningful decline in performance (6 m gait speed, 400-m walk time (400MWT), Short Physical Performance Battery, and Health ABC Physical Performance Battery (PPB), based on self-reported perceived mobility anchors (climbing 10 steps and walking ¼ mile). Estimates were stratified by initial performance, demographics, health status, chronic conditions, and body mass index, and compared across strata.

RESULTS

For all four measures, small and substantial decline estimates were generally consistent among subgroups based on initial performance, demographics, health status, and chronic conditions. The only exception was for 400MWT, where men had greater estimates than women. For PPB, small change was 0.12 points, and substantial change was 0.22 points.

CONCLUSIONS

Estimates of small and substantial meaningful decline resemble those previously reported for gait speed, 400MWT, and SPPB. Magnitudes of meaningful performance decline appear to be generally consistent across strata of initial performance, demographics, health status, body mass index, and chronic conditions.

A variant of sparse partial least squares for variable selection and data exploration

When data are sparse and/or predictors multicollinear, current implementation of sparse partial least squares (SPLS) does not give estimates for non-selected predictors nor provide a measure of inference. In response, an approach termed “all-possible” SPLS is proposed, which fits a SPLS model for all tuning parameter values across a set grid. Noted is the percentage of time a given predictor is chosen, as well as the average non-zero parameter estimate. Using a “large” number of multicollinear predictors, simulation confirmed variables not associated with the outcome were least likely to be chosen as sparsity increased across the grid of tuning parameters, while the opposite was true for those strongly associated. Lastly, variables with a weak association were chosen more often than those with no association, but less often than those with a strong relationship to the outcome. Similarly, predictors most strongly related to the outcome had the largest average parameter estimate magnitude, followed by those with a weak relationship, followed by those with no relationship. Across two independent studies regarding the relationship between volumetric MRI measures and a cognitive test score, this method confirmed a priori hypotheses about which brain regions would be selected most often and have the largest average parameter estimates. In conclusion, the percentage of time a predictor is chosen is a useful measure for ordering the strength of the relationship between the independent and dependent variables, serving as a form of inference. The average parameter estimates give further insight regarding the direction and strength of association. As a result, all-possible SPLS gives more information than the dichotomous output of traditional SPLS, making it useful when undertaking data exploration and hypothesis generation for a large number of potential predictors.

Macular pigment optical density is related to cognitive function in older people

BACKGROUND

the xanthophylls lutein (L) and zeaxanthin (Z) exist in relatively high concentration in multiple central nervous tissues (e.g. cortex and neural retina). L + Z in macula (i.e. macular pigment, MP) are thought to serve multiple functions, including protection and improvement of visual performance. Also, L + Z in the macula are related to L + Z in the cortex.

OBJECTIVE

to determine whether macular pigment optical density (MPOD, L + Z in the macula) is related to cognitive function in older adults.

METHODS

participants were older adults (n = 108, 77.6 ± 2.7 years) sampled from the age-related maculopathy ancillary study of the Health Aging and Body Composition Study (Memphis, TN, USA). Serum carotenoids were measured using high performance liquid chromatography. MPOD was assessed using heterochromatic flicker photometry. Eight cognitive tests designed to evaluate several cognitive domains including memory and processing speed were administered. Partial correlation coefficients were computed to determine whether cognitive measures were related to serum L + Z and MPOD.

RESULTS

MPOD levels were significantly associated with better global cognition, verbal learning and fluency, recall, processing speed and perceptual speed, whereas serum L + Z was significantly related to only verbal fluency.

CONCLUSION

MPOD is related to cognitive function in older people. Its role as a potential biomarker of cognitive function deserves further study.

Physical activity predicts microstructural integrity in memory-related networks in very old adults

BACKGROUND

Although the beneficial effects of physical activity (PA) on memory and executive function are well established in older adults, little is known about the relationship between PA and brain microstructure and the contributions of physical functional limitations and chronic diseases. This study examined whether higher PA would be longitudinally associated with greater microstructural integrity in memory- and executive function-related networks and whether these associations would be independent of physical function and chronic diseases.

METHODS

Diffusion tensor imaging was obtained in 2006-2008 in 276 participants (mean age = 83.0 years, 58.7% female, 41.3% black) with PA (sedentary, lifestyle active, and exercise active) measured in 1997-1998. Gait speed, cognition, depressive symptoms, cardiovascular and pulmonary diseases, hypertension, stroke, and diabetes were measured at both time points. Mean diffusivity and fractional anisotropy were computed from normal-appearing gray and white matter in frontoparietal and subcortical networks. Moderating effects of physical function and chronic diseases were tested using hierarchical regression models.

RESULTS

Compared with the sedentary, the exercise active group had lower mean diffusivity in the medial temporal lobe and the cingulate cortex (β, p values: -.405, .023 and -.497, .006, respectively), independent of age, sex, and race. Associations remained independent of other variables, although they were attenuated after adjustment for diabetes. Associations between PA and other neuroimaging markers were not significant.

CONCLUSIONS

Being exercise active predicts greater memory-related microstructural integrity in older adults. Future studies in older adults with diabetes are warranted to examine the neuroprotective effect of PA in these networks.

Assessing fatigability in mobility-intact older adults

OBJECTIVES

To evaluate the criterion validity of two measures of fatigability, defined as performance deterioration or perceived effort to perform a standardized task.

DESIGN

Cross-sectional analysis of data from the Baltimore Longitudinal Study of Aging (BLSA).

SETTING

National Institute on Aging, Intramural Research Program, Clinical Research Unit, Baltimore, Maryland.

PARTICIPANTS

Six hundred five men (53.7%) and women aged 65 to 97 participating in the BLSA and eligible for endurance walk testing without a walking aid.

MEASUREMENTS

Fatigability was assessed using completion status and lap times from a 400-m walk performed "as quickly as possible" and perceived exertion rating using the Borg scale (range 6-20) after 5 minutes of treadmill walking at 1.5 miles per hour (0.67 m/s). Criterion measures included self-report of tiredness, level of weakness and energy in past month, and walking ability and objective measures of usual and fast gait speed, time to complete 10 chair stands, and grip strength. Covariates included age, race, sex, obesity, smoking status, and walking activity.

RESULTS

Of mobility-intact older persons, 23% exhibited performance deterioration (slowed or stopped) during the 400-m walk, and one-third reported more than very light exertion after a 5-minute slow walk. Slowing was strongly associated with self-reported fatigue and walking ability but weakly associated with performance-based mobility measures. High perceived exertion was associated with tiredness, weakness, and reported and observed mobility deficits.

CONCLUSION

Slowing down may have low sensitivity for identifying fatigability in older persons, but ascertaining perceived exertion during a defined workload shows promise. In seemingly healthy, motivated individuals, fatigue and fatigability were common and may affect socially meaningful mobility behaviors. Assessment of fatigability in well-elderly examinations may help identify threats to independent functioning earlier in the decline process.

GRACE: A visual comparison framework for integrated spatial and non-spatial geriatric data

We present the design of a novel framework for the visual integration, comparison, and exploration of correlations in spatial and non-spatial geriatric research data. These data are in general high-dimensional and span both the spatial, volumetric domain--through magnetic resonance imaging volumes--and the non-spatial domain, through variables such as age, gender, or walking speed. The visual analysis framework blends medical imaging, mathematical analysis and interactive visualization techniques, and includes the adaptation of Sparse Partial Least Squares and iterated Tikhonov Regularization algorithms to quantify potential neurologymobility connections. A linked-view design geared specifically at interactive visual comparison integrates spatial and abstract visual representations to enable the users to effectively generate and refine hypotheses in a large, multidimensional, and fragmented space. In addition to the domain analysis and design description, we demonstrate the usefulness of this approach on two case studies. Last, we report the lessons learned through the iterative design and evaluation of our approach, in particular those relevant to the design of comparative visualization of spatial and non-spatial data.

Diabetes and risk of hospitalized fall injury among older adults

OBJECTIVE

To determine whether older adults with diabetes are at increased risk of an injurious fall requiring hospitalization.

RESEARCH DESIGN AND METHODS

The longitudinal Health, Aging, and Body Composition Study included 3,075 adults aged 70-79 years at baseline. Hospitalizations that included ICD-9-Clinical Modification codes for a fall and an injury were identified. The effect of diabetes with and without insulin use on the rate of first fall-related injury hospitalization was assessed using proportional hazards models.

RESULTS

At baseline, 719 participants had diabetes, and 117 of them were using insulin. Of the 293 participants who were hospitalized for a fall-related injury, 71 had diabetes, and 16 were using insulin. Diabetes was associated with a higher rate of injurious fall requiring hospitalization (hazard ratio [HR] 1.48 [95% CI 1.12-1.95]) in models adjusted for age, race, sex, BMI, and education. In those participants using insulin, compared with participants without diabetes, the HR was 3.00 (1.78-5.07). Additional adjustment for potential intermediaries, such as fainting in the past year, standing balance score, cystatin C level, and number of prescription medications, accounted for some of the increased risk associated with diabetes (1.41 [1.05-1.88]) and insulin-treated diabetes (2.24 [1.24-4.03]). Among participants with diabetes, a history of falling, poor standing balance score, and A1C level ≥8% were risk factors for an injurious fall requiring hospitalization.

CONCLUSIONS

Older adults with diabetes, in particular those using insulin, are at greater risk of an injurious fall requiring hospitalization than those without diabetes. Among those with diabetes, poor glycemic control may increase the risk of an injurious fall.

Frailty assessment in the cardiovascular care of older adults

Due to the aging and increasingly complex nature of our patients, frailty has become a high-priority theme in cardiovascular medicine. Despite the recognition of frailty as a pivotal element in the evaluation of older adults with cardiovascular disease (CVD), there has yet to be a road map to facilitate its adoption in routine clinical practice. Thus, we sought to synthesize the existing body of evidence and offer a perspective on how to integrate frailty into clinical practice. Frailty is a biological syndrome that reflects a state of decreased physiological reserve and vulnerability to stressors. Upward of 20 frailty assessment tools have been developed, with most tools revolving around the core phenotypic domains of frailty-slow walking speed, weakness, inactivity, exhaustion, and shrinking-as measured by physical performance tests and questionnaires. The prevalence of frailty ranges from 10% to 60%, depending on the CVD burden, as well as the tool and cutoff chosen to define frailty. Epidemiological studies have consistently demonstrated that frailty carries a relative risk of >2 for mortality and morbidity across a spectrum of stable CVD, acute coronary syndromes, heart failure, and surgical and transcatheter interventions. Frailty contributes valuable prognostic insights incremental to existing risk models and assists clinicians in defining optimal care pathways for their patients. Interventions designed to improve outcomes in frail elders with CVD such as multidisciplinary cardiac rehabilitation are being actively tested. Ultimately, frailty should not be viewed as a reason to withhold care but rather as a means of delivering it in a more patient-centered fashion.

Frailty and risk for heart failure in older adults: the health, aging, and body composition study

OBJECTIVE

The aim of this study was to assess the association between frailty and risk for heart failure (HF) in older adults.

BACKGROUND

Frailty is common in the elderly and is associated with adverse health outcomes. Impact of frailty on HF risk is not known.

METHODS

We assessed the association between frailty, using the Health ABC Short Physical Performance Battery (HABC Battery) and the Gill index, and incident HF in 2825 participants aged 70 to 79 years.

RESULTS

Mean age of participants was 74 ± 3 years; 48% were men and 59% were white. During a median follow up of 11.4 (7.1-11.7) years, 466 participants developed HF. Compared to non-frail participants, moderate (HR 1.36, 95% CI 1.08-1.71) and severe frailty (HR 1.88, 95% CI 1.02-3.47) by Gill index was associated with a higher risk for HF. HABC Battery score was linearly associated with HF risk after adjusting for the Health ABC HF Model (HR 1.24, 95% CI 1.13-1.36 per SD decrease in score) and remained significant when controlled for death as a competing risk (HR 1.30; 95% CI 1.00-1.55). Results were comparable across age, sex, and race, and in sub-groups based on diabetes mellitus or cardiovascular disease at baseline. Addition of HABC Battery scores to the Health ABC HF Risk Model improved discrimination (change in C-index, 0.014; 95% CI 0.018-0.010) and appropriately reclassified 13.4% (net-reclassification-improvement 0.073, 95% CI 0.021-0.125; P = .006) of participants (8.3% who developed HF and 5.1% who did not).

CONCLUSIONS

Frailty is independently associated with risk of HF in older adults.

Association between cerebellar gray matter volumes, gait speed, and information-processing ability in older adults enrolled in the Health ABC study

BACKGROUND

The cerebellum plays an important role in mobility and cognition. However, it is unclear which regions of the cerebellum are associated with gait speed and information-processing ability in older adults without overt brain damage.

METHODS

Cross-sectional associations between cerebellar gray matter volumes (GMV), gait speed, and information-processing ability were explored in 231 community-dwelling adults (mean age: 83 years, 48% black, 58% female). We measured gait speed on an automated walkway and information-processing ability on the Digit Symbol Substitution test (DSST). Total and regional cerebellar GMV was measured on 3T-magnetic resonance imaging. Lobar GMV of the cerebellum, obtained by an automated parcellation process, were aggregated based on the cognitive (lobules VI, VII, VIII and crus I, II), sensorimotor (lobules II, IV, V), and vestibular (lobules IX and X) functions ascribed to the cerebellar regions.

RESULTS

Larger cerebellar GMV correlated with faster gait speed and superior DSST scores (both p < .001) independent of age, gender, atrophy, and small vessel disease. After adjusting for age, gender, and atrophy, larger cognitive cerebellar GMV correlated with both faster gait speed (p = .04) and higher DSST scores (p < .001), larger sensorimotor cerebellar GMV correlated significantly with DSST alone (p = .02), and the vestibular cerebellar GMV with neither. The association between cognitive cerebellar GMV and gait speed was no longer significant after adjusting for DSST score in the linear regression models.

CONCLUSIONS

The relationship between gait speed and cerebellar GMV is influenced by information-processing ability, and this relationship is stronger in subregions ascribed to cognitive than vestibular or sensorimotor functions.

Changes in cholesterol-lowering medications use over a decade in community-dwelling older adults

BACKGROUND

The impact of evidence-based guidelines and controlled trial data on use of cholesterol-lowering medications in older adults is unclear.

OBJECTIVE

To examine whether utilization patterns of cholesterol-lowering medications in community-dwelling older adults changed following the release of the National Cholesterol Education Program Adult Treatment Panel III guidelines and results from the Prospective Study of Pravastatin in the Elderly at Risk in 2002.

METHODS

Community-dwelling elderly individuals who were enrolled in the Health, Aging and Body Composition Study in 1997-1998 were followed for up to 11 years. An interrupted time series analysis with multivariable generalized estimating equations (GEEs) was used to examine changes in level and trend in cholesterol-lowering medication use before and after 2002, adjusting for sociodemographics, health-related behaviors, and health status.

RESULTS

Cholesterol-lowering medication use increased nearly 3-fold from 14.9% in 1997-1998 to 42.6% in 2007-2008, with statins representing the most common class used (87-94%). Multivariable GEE results revealed no significant difference in the level of cholesterol-lowering medication use after 2002 (adjusted OR 0.95; 95% CI 0.89-1.02). Multivariable GEE results revealed that trend changes in the rate of increase in cholesterol-lowering medication declined after 2002 (adjusted ratio of ORs 0.92; 95% CI 0.89-0.95).

CONCLUSIONS

The use of cholesterol-lowering medication increased substantially over a decade in community-dwelling elderly individuals but was not related to a change in level or trend following the release of the guidelines and evidence-based data.

Body composition explains sex differential in physical performance among older adults

BACKGROUND

Older women have higher percent body fat, poorer physical function, lower strength, and higher rates of nonfatal chronic conditions than men. We sought to determine whether these differences explained physical performance differences between men and women.

METHODS

Physical performance was assessed in the Health, Aging and Body Composition study in 2,863 men and women aged 70-79 with a composite 0-4 point score consisting of chair stands, standing balance including one-leg stand, and 6-m usual and narrow walk tests. Total body composition was measured by dual x-ray absorptiometry, thigh composition by computed tomography, and knee extensor strength by isokinetic dynamometer. Analysis of covariance estimated least square mean performance scores for men and women.

RESULTS

Men had higher performance scores than women (least square means: 2.33±0.02 vs 2.03±0.02, p < .0001), adjusted for race, study site, age, and height. Body composition measures (total body fat and thigh muscle area, muscle density, subcutaneous fat, and intermuscular fat) accounted for differences between men and women (least square means: 2.15±0.02 vs 2.17±0.02, p = .53). Higher strength in men partly explained the sex difference (least square means: 2.28±0.02 vs 2.12±0.02, p < .0001). Strength attenuated the association of thigh muscle mass with performance. Chronic health conditions did not explain the sex difference.

CONCLUSIONS

In a well-functioning cohort, poorer physical function in women compared with men can be explained predominantly by their higher fat mass, but also by other body composition differences. The higher proportion of body fat in women may put them at significant biomechanical disadvantage for greater disability in old age.

INtensive versus standard ambulatory blood pressure lowering to prevent functional DeclINe in the ElderlY (INFINITY)

Reductions in mobility and cognitive function linked to accrual of brain microvascular disease related white matter hyperintensities (WMHs) on magnetic resonance imaging can occur in older hypertensive patients in as little as 2 years. We have designed a trial evaluating 2 levels of ambulatory blood pressure (ABP) control in individuals with normal or mildly impaired mobility and cognition who have detectable cerebrovascular disease (>0.5% WMH fraction of intracranial volume) on functional outcomes. The study is a prospective randomized, open-label trial with blinded end points, in patients ages ≥75 years with elevated 24-hour systolic blood pressure (BP) (145 mm Hg in the untreated state) who do not have unstable cardiovascular disease, heart failure, or stroke. The primary and key secondary outcomes in the trial are change from baseline in mobility and cognitive function and damage to brain white matter as demonstrated by accrual of WMH volume and changes in diffusion tensor imaging. Approximately 300 patients will be enrolled, and 200 randomized to 1 of 2 levels of ABP control (intensive to achieve a goal 24-hour systolic BP of ≤130 mm Hg or standard to achieve a goal 24-hour systolic BP of ≤145 mm Hg) for a total of 36 months using similar antihypertensive regimens. The analytical approach provides 85% power to show a clinically meaningful effect in differences in mobility accompanied by quantitative differences in WMH between treatment groups. The INFINITY trial is the first to guide antihypertensive therapy using ABP monitoring rather than clinic BP to reduce cerebrovascular disease.

Hearing loss and cognitive decline in older adults

BACKGROUND Whether hearing loss is independently associated with accelerated cognitive decline in older adults is unknown. METHODS We studied 1984 older adults (mean age, 77.4 years) enrolled in the Health ABC Study, a prospective observational study begun in 1997-1998. Our baseline cohort consisted of participants without prevalent cognitive impairment (Modified Mini-Mental State Examination [3MS] score, ≥80) who underwent audiometric testing in year 5. Participants were followed up for 6 years. Hearing was defined at baseline using a pure-tone average of thresholds at 0.5 to 4 kHz in the better-hearing ear. Cognitive testing was performed in years 5, 8, 10, and 11 and consisted of the 3MS (measuring global function) and the Digit Symbol Substitution test (measuring executive function). Incident cognitive impairment was defined as a 3MS score of less than 80 or a decline in 3MS score of more than 5 points from baseline. Mixed-effects regression and Cox proportional hazards regression models were adjusted for demographic and cardiovascular risk factors. RESULTS In total, 1162 individuals with baseline hearing loss (pure-tone average >25 dB) had annual rates of decline in 3MS and Digit Symbol Substitution test scores that were 41% and 32% greater, respectively, than those among individuals with normal hearing. On the 3MS, the annual score changes were -0.65 (95% CI, -0.73 to -0.56) vs -0.46 (95% CI, -0.55 to -0.36) points per year (P = .004). On the Digit Symbol Substitution test, the annual score changes were -0.83 (95% CI, -0.94 to -0.73) vs -0.63 (95% CI, -0.75 to -0.51) points per year (P = .02). Compared to those with normal hearing, individuals with hearing loss at baseline had a 24% (hazard ratio, 1.24; 95% CI, 1.05-1.48) increased risk for incident cognitive impairment. Rates of cognitive decline and the risk for incident cognitive impairment were linearly associated with the severity of an individual's baseline hearing loss. CONCLUSIONS Hearing loss is independently associated with accelerated cognitive decline and incident cognitive impairment in community-dwelling older adults. Further studies are needed to investigate what the mechanistic basis of this association is and whether hearing rehabilitative interventions could affect cognitive decline.

Can failure on adaptive locomotor tasks independently predict incident mobility disability?

This study examined whether inability to perform adaptive locomotor tests predicts self-reported incident mobility disability. InCHIANTI study participants (N = 611; age, 50-85 yrs) who could walk 7 m at self-selected speed and who had no self-reported mobility disability at baseline were included. The ability to complete four adaptive locomotor tests was assessed: fast walking, walking on a narrow path, crossing obstacles while walking, and talking while walking. Mobility disability was recorded again at 3-yr follow-up. Failure in the fast-walking and narrow-path walking tests predicted approximately 2.5 times likelihood of reporting incident mobility disability (P = 0.009 and P = 0.011, respectively). Failure in the obstacle-crossing test predicted approximately two times likelihood of reporting incident mobility disability; however, this result did not reach statistical significance (P = 0.077). Failure in talking while walking did not predict incident mobility disability. Those who failed both the fast-walking and narrow-path walking tests were almost nine times as likely to report incident mobility disability.

The relationship of the energetic cost of slow walking and peak energy expenditure to gait speed in mid-to-late life

OBJECTIVE

Peak energy expenditure is highly correlated with usual gait speed; however, it is unknown whether the energetic cost of walking is also an important contributor to usual gait speed when considered as a component of peak walking capacity.

DESIGN

The energetic cost of 5 mins of slow treadmill walking (0.67 m/sec), peak overground walking energy expenditure, and usual gait speed over 6 m were assessed cross-sectionally in 405 adults aged 33 to 94 yrs in the Baltimore Longitudinal Study of Aging.

RESULTS

Mean (SD) energy expenditures during slow and peak sustained walking were 8.9 (1.4) and 18.38 (4.8) ml kg(-1) min(-1), respectively. Overall, the energetic cost of slow walking as a percentage of peak walking energy expenditure was strongly associated with usual gait speed (P < 0.001); however in stratified analyses, this association was maintained only in those with peak walking capacity below 18.3 ml kg(-1) min(-1) (P = 0.04), the threshold associated with independent living.

CONCLUSIONS

In older persons with substantially reduced peak walking capacity, the energetic cost of walking is associated with gait speed, particularly when peak walking capacity nears the minimum level considered necessary for independent living. Thus, optimal habilitation in older frail persons may benefit from both improving fitness and reducing the energetic cost of walking.

Assessing physical function and physical activity in patients with CKD

Patients with CKD are characterized by low levels of physical functioning, which, along with low physical activity, predict poor outcomes in those treated with dialysis. The hallmark of clinical care in geriatric practice and geriatric research is the orientation to and assessment of physical function and functional limitations. Although there is increasing interest in physical function and physical activity in patients with CKD, the nephrology field has not focused on this aspect of care. This paper provides an in-depth review of the measurement of physical function and physical activity. It focuses on physiologic impairments and physical performance limitations (impaired mobility and functional limitations). The review is based on established frameworks of physical impairment and functional limitations that have guided research in physical function in the aging population. Definitions and measures for physiologic impairments, physical performance limitations, self-reported function, and physical activity are presented. On the basis of the information presented, recommendations for incorporating routine assessment of physical function and encouragement for physical activity in clinical care are provided.

Validation of a mobility item bank for older patients in primary care

BACKGROUND

To develop and validate an item bank to measure mobility in older people in primary care and to analyse differential item functioning (DIF) and differential bundle functioning (DBF) by sex.

METHODS

A pool of 48 mobility items was administered by interview to 593 older people attending primary health care practices. The pool contained four domains based on the International Classification of Functioning: changing and maintaining body position, carrying, lifting and pushing, walking and going up and down stairs.

RESULTS

The Late Life Mobility item bank consisted of 35 items, and measured with a reliability of 0.90 or more across the full spectrum of mobility, except at the higher end of better functioning. No evidence was found of non-uniform DIF but uniform DIF was observed, mainly for items in the changing and maintaining body position and carrying, lifting and pushing domains. The walking domain did not display DBF, but the other three domains did, principally the carrying, lifting and pushing items.

CONCLUSIONS

During the design and validation of an item bank to measure mobility in older people, we found that strength (carrying, lifting and pushing) items formed a secondary dimension that produced DBF. More research is needed to determine how best to include strength items in a mobility measure, or whether it would be more appropriate to design separate measures for each construct.

25-hydroxyvitamin D status and change in physical performance and strength in older adults: the Health, Aging, and Body Composition Study

Low 25-hydroxyvitamin D (25(OH)D) concentrations are common among older adults and are associated with poorer physical performance and strength, but results from longitudinal studies have been inconsistent. The 25(OH)D threshold for physical performance and strength was determined, and both cross-sectional and longitudinal associations between 25(OH)D and physical performance and strength were examined, in men and women aged 71-80 years from the Health, Aging, and Body Composition Study (n = 2,641). Baseline serum 25(OH)D was measured in 1998-1999, and physical performance and strength were measured at baseline and at 2- and 4-year follow-up. Piecewise regression models were used to determine 25(OH)D thresholds. Linear regression and mixed models were used to examine cross-sectional and longitudinal associations. The 25(OH)D thresholds were 70-80 nmol/L for physical performance and 55-70 nmol/L for strength. Participants with 25(OH)D <50 nmol/L had poorer physical performance at baseline and at 2- and 4-year follow-up than participants with 25(OH)D ≥75 nmol/L (P < 0.01). Although physical performance and strength declined over 4 years of follow-up (P < 0.0001), in general, the rate of decline was not associated with baseline 25(OH)D. Older adults with low 25(OH)D concentrations had poorer physical performance over 4 years of follow-up, but low 25(OH)D concentrations were not associated with a faster rate of decline in physical performance or strength.