Age-related losses of lean mass and shifts to central adiposity are related to functional decline and may predict mortality and/or explain part of the risk of weight loss. To determine how mortality ...risk is related to shifts in body composition, changes should be considered in the context of overall weight change.
Five-year changes in body composition were assessed with computed tomography (cm2) and dual x-ray absorptiometry (kg) in 869 men and 934 women initially aged 70-79 years. All-cause mortality was monitored for up to 12 years (2002-2003 to September 30, 2014), and risk was assessed using sex-specific Cox models.
Both men and women lost weight, visceral fat area, thigh muscle area, lean mass, and fat mass (all p < .01) but gained intermuscular thigh fat area (p < .01). There were 995 deaths. After adjustment for total weight change, demographics, and chronic disease, losing thigh muscle area was associated with higher mortality in both men (1.21, 1.08-1.35) and women (1.18, 1.01-1.37, per 9.0cm2) and was especially strong in normal weight (body mass index < 25kg/m2) individuals and those losing weight. Losing intermuscular thigh fat was protective against mortality only in normal weight (0.66, 0.51-0.86) and weight stable men (0.79, 0.66-0.95, per 3.2cm2). Changes in visceral fat area were not associated with mortality.
Older adults with greater loss of thigh muscle than expected for overall weight change had a higher mortality risk compared to those with relative thigh muscle preservation, suggesting that conservation of muscle mass is important for survival in old age.
Obesity and chronic low-grade inflammation have both been implicated in the onset of physical fatigue. However, few studies have investigated the independence of these associations in older ...community-dwelling populations. We therefore aimed to investigate the associations of body mass index (BMI) and inflammatory markers at age 60-64 with perceived physical fatigability at age 68 and to assess whether any such associations were independent of each other and potential confounding factors. A secondary aim was to investigate whether any association with BMI extended back into earlier adulthood.
Participants of the MRC National Survey of Health and Development (N = 1580) had BMI and levels of interleukin-6 (IL-6) and C-reactive protein (CRP) measured during clinical assessments at age 60-64. These were related to self-perceived physical fatigability assessed at age 68 using the Pittsburgh Fatigability Scale (PFS) (total score:0 (no physical fatigue)-50 (extreme physical fatigue)).
Women had higher mean PFS scores than men (mean (SD): 16.0 (9.1) vs 13.2 (8.9), p < 0.01). In sex-adjusted models, BMI, CRP and IL-6 were each associated with PFS scores. When all three factors were included in the same model, BMI and IL-6 remained associated with PFS scores whereas CRP did not. After adjustment for a range of potential confounders, associations of BMI and IL-6 with PFS scores were still evident; fully adjusted differences in mean PFS score = 3.41 (95% CI: 0.59, 6.24) and 1.65 (0.46, 2.84) for underweight and obese participants when compared with normal weight and, 2.78 (1.65, 3.91) when comparing those with an IL-6 of 2.51-8.49 pg/mL with levels <1.50.
BMI and inflammation may both be suitable targets for intervention to reduce the burden of physical fatigability in later life. Further, interventions that target both obesity and elevated levels of IL-6 are likely to be more effective than those focusing on only one.
OBJECTIVES
Analyses performed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) identified cut‐points in several metrics of grip strength for consideration in a definition of sarcopenia. ...We describe the associations between the SDOC‐identified metrics of low grip strength (absolute or standardized to body size/composition); low dual‐energy x‐ray absorptiometry (DXA) lean mass as previously defined in the literature (appendicular lean mass ALM/ht2); and slowness (walking speed <.8 m/s) with subsequent adverse outcomes (falls, hip fractures, mobility limitation, and mortality).
DESIGN
Individual‐level, sex‐stratified pooled analysis. We calculated odds ratios (ORs) or hazard ratios (HRs) for incident falls, mobility limitation, hip fractures, and mortality. Follow‐up time ranged from 1 year for falls to 8.8 ± 2.3 years for mortality.
SETTING
Eight prospective observational cohort studies.
PARTICIPANTS
A total of 13,421 community‐dwelling men and 4,828 community‐dwelling women.
MEASUREMENTS
Grip strength by hand dynamometry, gait speed, and lean mass by DXA.
RESULTS
Low grip strength (absolute or standardized to body size/composition) was associated with incident outcomes, usually independently of slowness, in both men and women. ORs and HRs generally ranged from 1.2 to 3.0 for those below vs above the cut‐point. DXA lean mass was not consistently associated with these outcomes. When considered together, those who had both muscle weakness by absolute grip strength (<35.5 kg in men and <20 kg in women) and slowness were consistently more likely to have a fall, hip fracture, mobility limitation, or die than those without either slowness or muscle weakness.
CONCLUSION
Older men and women with both muscle weakness and slowness have a higher likelihood of adverse health outcomes. These results support the inclusion of grip strength and walking speed as components in a summary definition of sarcopenia. J Am Geriatr Soc 68:1429‐1437, 2020.
See related editorial by Cesari et al in this issue
Background
Physical activity (PA) reduces the rate of mobility disability, compared with health education (HE), in at risk older adults. It is important to understand aspects of performance ...contributing to this benefit.
Objective
To evaluate intervention effects on tertiary physical performance outcomes.
Design
The Lifestyle Interventions and Independence for Elders (LIFE) was a multi‐centered, single‐blind randomized trial of older adults.
Setting
Eight field centers throughout the United States.
Participants
1635 adults aged 78.9 ± 5.2 years, 67.2% women at risk for mobility disability (Short Physical Performance Battery SPPB <10).
Interventions
Moderate PA including walking, resistance and balance training compared with HE consisting of topics relevant to older adults.
Outcomes
Grip strength, SPPB score and its components (balance, 4 m gait speed, and chair‐stands), as well as 400 m walking speed.
Results
Total SPPB score was higher in PA versus HE across all follow‐up times (overall P = .04) as was the chair‐stand component (overall P < .001). No intervention effects were observed for balance (overall P = .12), 4 m gait speed (overall P = .78), or grip strength (overall P = .62). However, 400 m walking speed was faster in PA versus HE group (overall P =<.001). In separate models, 29% of the rate reduction of major mobility disability in the PA versus HE group was explained by change in SPPB score, while 39% was explained by change in the chair stand component.
Conclusion
Lower extremity performance (SPPB) was significantly higher in the PA compared with HE group. Changes in chair‐stand score explained a considerable portion of the effect of PA on the reduction of major mobility disability–consistent with the idea that preserving muscle strength/power may be important for the prevention of major mobility disability.
Hospitalization-associated functional decline is a common problem for older adults, but it is unclear how hospitalizations affect physical performance measures such as gait speed. We sought to ...determine hospitalization-associated change in gait speed and likelihood of new limitations in mobility and activities of daily living (ADLs).
We used longitudinal data over 5 years from the Health, Aging and Body Composition Study, a prospective cohort of black and white community-dwelling men and women, aged 70-79 years, who had no limitations in mobility (difficulty walking 1/4 mile or climbing 10 steps) or ADLs (transferring, bathing, dressing, and eating) at baseline. Gait speed, and new self-reported limitations in mobility and ADLs were assessed annually. Selected participants (n = 2,963) had no limitations at the beginning of each 1-year interval. Hospitalizations were self-reported every 6 months and verified with medical record data. Generalized estimating equations were used to examine hospitalization-associated change in gait speed and odds of new limitations over each 1-year interval. Fully adjusted models included demographics, hospitalization within the past year, health conditions, symptoms, body mass index, and health-related behaviors.
In fully adjusted models, any hospitalization was associated with decrease in gait speed (-0.04 m/s; 95% confidence interval CI: -0.05 to -0.03) and higher odds of new limitations in mobility or ADLs (odds ratio = 1.97, 95% CI: 1.70-2.28), and separately with increased odds of new mobility limitation (odds ratio = 2.22, 95% CI: 1.90-2.60) and new ADL limitations (odds ratio = 1.84, 95% CI: 1.53-2.21). Multiple hospitalizations within a year were associated with gait speed decline (-0.06 m/s; 95% CI: -0.08 to -0.04) and greater odds of new limitations in mobility or ADLs (odds ratio = 2.96, 95% CI: 2.23-3.95).
Functionally independent older adults experienced hospitalization-associated declines in gait speed and new limitations in mobility and ADLs.
Abstract
Background
Mobility limitations are common, with higher prevalence in African Americans compared with whites, and are associated with disability, institutionalization, and death. Aging is ...associated with losses of lean mass and a shift to central adiposity, which are more pronounced in African Americans. We aimed to examine the association of body composition remodeling with incident mobility limitations in older men of African ancestry.
Methods
Seven-year changes in body composition were measured using peripheral quantitative computed tomography (pQCT) of the calf and whole-body dual x-ray absorptiometry (DXA) in 505 African ancestry men aged ≥60 years and free of self-reported mobility limitations at baseline. Self-reported incident mobility limitations were assessed at 7-year follow-up. Odds of developing mobility limitations associated with baseline and change in body composition were quantified using separate logistic regression models.
Results
Seventy-five men (14.9%) developed incident mobility limitations over 6.2 ± 0.6 years. Baseline body composition was not associated with incident mobility limitations. After adjustment for covariates, gaining total and intermuscular fat were associated with incident mobility limitations (odds ratio OR: 1.60; 95% confidence interval CI: 1.21–2.13; OR: 1.51; 95% CI: 1.18–1.94). Changes in DXA lean mass were not related to mobility limitations; however, maintaining pQCT calf muscle area was protective against mobility limitations (OR: 0.65; 95% CI: 0.48–0.87).
Conclusions
Increases in body fat, and particularly intermuscular fat, and decreases in calf skeletal muscle area were associated with a higher risk of developing mobility limitations. Our findings emphasize the importance of body composition remodeling in the development of mobility limitations among African ancestry men.
OBJECTIVES
To evaluate the Pittsburgh Fatigability Scale (PFS) as a predictor of performance and functional decline in mobility‐intact older adults.
DESIGN
Longitudinal analysis of Baltimore ...Longitudinal Study of Aging data.
SETTING
National Institute on Aging, Clinical Research Unit, Baltimore, Maryland.
PARTICIPANTS
Mobility‐intact men (46.8%) and women aged 60 to 89 with concurrent PFS administration and performance and functional assessment and follow‐up assessment within 1 to 4 years (N=579).
MEASUREMENTS
The PFS is a self‐administered, 1‐page assessment of expected physical and mental fatigue with a score ranging from 0 (no) to 5 (extreme) associated with performing 10 activities. Analyses examined associations between each dimension scored continuously (0–50), categorically (0–5), and dichotomously and change in and likelihood of clinically meaningful decline in usual and fast gait speed, chair stand pace, and reported walking ability. Covariates included age, age2, sex, race, visit status, baseline function, and follow‐up time. We defined meaningful decline as 0.05 m/s per year for usual gait speed, 0.07 m/s per year for fast gait speed, 0.02 chair stands/s per year and 1 point or more for walking ability index.
RESULTS
Over a mean 2.2 years, 20.5% to 37.7% of participants experienced meaningful decline across assessments. Independent of covariates, higher PFS physical and mental scores were most consistently associated with greater decline in usual gait speed, chair stand pace, and reported walking ability regardless of scoring approach. For example, higher physical fatigability was associated with twice the likelihood of meaningful decline in gait speed as lower physical fatigability (p=.001). PFS scores were superior to fatigue symptoms such as tiredness and energy level in predicting performance decline, which showed no association.
CONCLUSION
Routine self‐administered perceived fatigability assessment may help identify older persons vulnerable to accelerated mobility decline. J Am Geriatr Soc 66:2092–2096, 2018.
Objectives
To describe the development of the Pittsburgh Fatigability Scale (PFS) and establish its reliability and concurrent and convergent validity against performance measures.
Design
...Cross‐sectional.
Setting
University of Pittsburgh, Pittsburgh, Pennsylvania.
Participants
Scale development sample: 1,013 individuals aged 60 and older from two registries; validation sample: 483 adults aged 60 and older from the Baltimore Longitudinal Study of Aging (BLSA).
Measurements
The scale development sample and BLSA participants self‐administered an initial 26‐item perceived fatigability scale. BLSA participants also completed measures of performance fatigability (perceived exertion from a standard treadmill task and performance deterioration from a fast‐paced long‐distance corridor walk), a 6‐m usual‐paced corridor walk, and five timed chair stands.
Results
Principal components analysis with varimax rotation reduced the 26‐item scale to the 10‐item PFS. The PFS showed strong internal consistency (Cronbach's alpha 0.88) and excellent test–retest reliability (intraclass correlation 0.86). In the validation sample, PFS scores, adjusted for age, sex, and race, were greater for those with high performance fatigability, slow gait speed, worse physical function, and lower fitness, with differences between high and low fatigability ranging from 3.2 to 5.1 points (P < .001).
Conclusion
The 10‐item PFS physical fatigability score is a valid and reliable measure of perceived fatigability in older adults and can serve as an adjunct to performance‐based fatigability measures for identifying older adults at risk of mobility limitation in clinical and research settings.
Objectives
To investigate the heterogeneity of clinically meaningful levels of gait speed relative to self‐reported mobility disability (SR‐MD).
Design
Five longitudinal studies with older adults in ...different health states (onset of acute event, presence of chronic condition, sedentary, community living) were used to explore the relationship between gait speed and SR‐MD.
Setting
Lifestyle Interventions and Independence for Elders Pilot (LIFE‐P), LIFE, Trial of Angiotensin‐Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN), Baltimore Hip Fracture Study (BHS2), Invecchiare in Chianti (InCHIANTI).
Participants
Individuals aged 65 and older (N=3,540): sedentary, community dwelling (LIFE‐P/LIFE), with hip fracture (BHS2), random population‐based sample (InCHIANTI), high cardiovascular risk (TRAIN).
Measurements
Usual‐pace gait speed across 3 to 4 m and SR‐MD, defined as inability to walk approximately 1 block or climb 1 flight of stairs.
Results
The mean gait speed of participants without SR‐MD was greater than 1.0 m/s in InCHIANTI and TRAIN, 0.79 m/s in LIFE‐P/LIFE, and 0.46 m/sec in BHS2. Of individuals with SR‐MD, mean gait speed was 0.08 m/s slower in LIFE‐P/LIFE, 0.19 m/s slower in TRAIN, 0.22 m/s slower in BHS2, and 0.36 m/s slower in InCHIANTI. The optimal gait speed cutpoint for minimizing SR‐MD misclassification rates ranged from 0.3 m/s in BHS2 to 1.0 m/s in TRAIN. In longitudinal analyses, development of SR‐MD was dependent on initial gait speed and change in gait speed (p<.001).
Conclusion
The relationship between absolute levels of gait speed and SR‐MD may be context specific, and there may be variations between populations. Across diverse clinical populations, clinical interpretations of how change in usual pace gait speed relates to development of SR‐MD depend on where on the gait speed continuum change occurs.
Background
Fatigue, inflammation, and physical activity (PA) are all independently associated with gait speed, but their directionality is not fully elucidated.
Aims
Evaluate the bidirectional ...associations amongst fatigue, inflammation, and PA on gait speed.
Methods
This cross sectional study included probands (
n
= 1280, aged 49–105) and offspring (
n
= 2772, aged 24–88) in the Long Life Family Study. We assessed gait speed, fatigue with the question “I could not get going”, inflammation using fasting interleukin-6 (IL-6) and high sensitivity C-reactive protein (CRP), and self-reported PA as walking frequency in the past two weeks. The two generations were examined separately using linear mixed modeling.
Results
Lower fatigue, lower IL-6, and greater PA were all associated with faster gait speed in both generations (all
p
< 0.05); lower CRP was only associated with faster gait speed in the offspring. PA explained the association of fatigue and gait speed via a 16.1% (95% CI 9.7%, 26.7%) attenuation of the direct associations for the probands and 9.9% (95% CI 6.3%, 18.8%) in the offspring. In addition, IL-6 explained more of the association of fatigue and gait speed than the association between PA and gait speed, via a 14.9% (95% CI 9.2%, 23.4%) attenuation of the direct association in the offspring only.
Discussion
Results revealed a potential directionality from fatigue to IL-6 to PA that may lead to faster gait speed. Future work should examine these relationships longitudinally to establish temporality and causality.
Conclusions
Our findings support a signal that lowering fatigue and inflammation and increasing physical activity may delay functional decline.
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