Sustained IL-6 and sTNF-αR1 levels after hip fracture predict 5-year mortality: A prospective cohort study from the Baltimore Hip Studies.

BACKGROUND: Persistent inflammation is associated with adverse health outcomes, but its impact on mortality has not been investigated previously among hip fracture patients. This article aims to investigate the influence of changes in levels of cytokines in the 2 months after a hip fracture repair on 5-year mortality. METHODS: This is a prospective cohort study from the Baltimore Hip Studies (BHS) with 191 community-dwelling older men and women (≥65 years) who had recently undergone surgical repair of an acute hip fracture, with recruitment from May 2006 to June 2011. Plasma interleukin-6 (IL-6), soluble tumor necrosis factor alpha receptor1 (sTNFα-R1), and interleukin-1 receptor agonist (IL-1RA) were obtained within 22 days of admission and at 2 months. All-cause mortality over 5 years was determined. Logistic regression analysis tested the associations between the cytokines' trajectories and mortality over 5 years, adjusted for covariates (age, sex, education, body mass index, lower extremity physical activities of daily living, and Charlson comorbidity index). RESULTS: High levels of IL-6 and sTNFα-R1 at baseline with small or no decline at 2 months were associated with higher odds of 5-year mortality compared with those with lower levels at baseline and greater decline at 2 months after adjustment for age, and other potential confounders (OR = 4.71, p = 0.01 for IL-6; OR = 15.03, p = 0.002 for sTNFα-R1). Similar results that failed to reach significance were found for IL-1RA (OR = 2.40, p = 0.18). Those with higher levels of cytokines at baseline with greater decline did not have significantly greater mortality than the reference group, those with lower levels at baseline and greater decline. CONCLUSION: Persistent elevation of plasma IL-6 and sTNFα-R1 levels within the first 2 months after hospital admission in patients with hip fracture is associated with higher 5-year mortality. These patients may benefit from enhanced care and earlier intensive interventions to reduce the risk of death.

Effects of Multicomponent Home-Based Intervention on Muscle Composition, Fitness, and Bone Density After Hip Fracture.

BACKGROUND: Mechanistic factors on the pathway to improving independent ambulatory ability among hip fracture patients by a multicomponent home-based physical therapy intervention that emphasized aerobic, strength, balance, and functional training are unknown. The aim of this study was to determine the effects of 2 different home-based physical therapy programs on muscle area and attenuation (reflects muscle density) of the lower extremities, bone mineral density (BMD), and aerobic capacity. METHODS: Randomized controlled trial of home-based 16 weeks of strength, endurance, balance, and function exercises (PUSH, n = 19) compared to seated active range-of-motion exercises and transcutaneous electrical neurostimulation (PULSE, n = 18) in community-dwelling adults >60 years of age within 26 weeks of hip fracture. RESULTS: In PUSH and PULSE groups combined, the fractured leg had lower muscle area and muscle attenuation and higher subcutaneous fat than the nonfractured leg (p < .001) at baseline. At 16 weeks, mean muscle area of the fractured leg was higher in the PUSH than PULSE group (p = .04). Changes in muscle area were not significantly different when compared to the comparative PULSE group. There was a clinically relevant difference in change in femoral neck BMD between groups (p = .05) that showed an increase after PULSE and decrease after PUSH. There were generally no between-group differences in mean VO2peak tests at 16-week follow-up, except the PUSH group reached a higher max incline (p = .04). CONCLUSIONS: The treatment effects of a multicomponent home-based physical therapy intervention on muscle composition, BMD, and aerobic capacity were not significantly different than an active control intervention in older adults recovering from hip fracture. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01783704.

Evaluation of Dynamic Effects of Depressive Symptoms on Physical Function in Knee Osteoarthritis.

OBJECTIVE: To assess how changes in depressive symptoms influence physical function over time among those with radiographic knee osteoarthritis (OA). METHODS: Participants from the Osteoarthritis Initiative with radiographic knee OA (n = 2,212) and complete data were identified at baseline. Depressive symptoms were assessed as a time-varying score at baseline and the first three annual follow-up visits using the Center for Epidemiological Studies Depression Scale (CES-D) Scale. Physical function was measured at the first four follow-up visits using 20-meter gait speed meters per second. The following two marginal structural models were fit: one assessing the main effect of depressive symptoms on gait speed and another assessing time-specific associations. RESULTS: Time-adjusted results indicated that higher CES-D scores were significantly associated with slower gait speed (-0.0048; 95% confidence interval -0.0082 to -0.0014), and time-specific associations of CES-D were largest during the first follow-up interval (-0.0082; 95% confidence interval -0.0128 to -0.0035). During subsequent follow-up time points, the influence of depressive symptoms on gait speed diminished. CONCLUSION: The negative effect of depressive symptoms on physical function may decrease over time as knee OA progresses.

Shoulder pain, health-related quality of life and physical function in community-dwelling older adults.

The impact of shoulder pain on health-related quality of life and physical function among community-dwelling older adults (>60 years) not seeking medical care is not well understood. Forty-four community-dwelling older adult volunteers with low comorbidity were stratified into two groups by the presence (n = 18) or absence (n = 26) of shoulder pain. Participants completed the 36-Item Short Form and American Shoulder and Elbow Surgeon surveys and received shoulder range of motion and magnetic resonance imaging testing. Participants with shoulder pain perceived more difficulty accomplishing usual tasks secondary to their physical and emotion health and displayed inferior shoulder function, relative to participants without shoulder pain. This study suggests that shoulder pain reduces quality of life and physical function in the population of community-dwelling older adults not seeking medical evaluation for their symptoms.

Effect of Multicomponent Home-Based Training on Gait and Muscle Strength in Older Adults After Hip Fracture Surgery: A Single Site Randomized Trial.

OBJECTIVE: To investigate the effect of 16-week home-based physical therapy interventions on gait and muscle strength. DESIGN: A single-blinded randomized controlled trial. SETTING: General community. PARTICIPANTS: Thirty-four older adults (N=34) post hip fracture were randomly assigned to either experimental group (a specific multi-component intervention group [PUSH], n=17, 10 women, age=78.6±7.3 years, 112.1±39.8 days post-fracture) or active control (a non-specific multi-component intervention group [PULSE], n=17, 11 women, age=77.8±7.8 years, 118.2±37.5 days post-fracture). INTERVENTION: PUSH and PULSE groups received 32-40 sessions of specific or non-specific multi-component home-based physical therapy, respectively. Training in the PUSH group focused on lower extremity strength, endurance, balance, and function for community ambulation, while the PULSE group received active movement and transcutaneous electrical nerve stimulation on extremities. MAIN OUTCOME MEASURES: Gait characteristics, and ankle and knee muscle strength were measured at baseline and 16 weeks. Cognitive testing of Trail Making Test (Part A: TMT-A; Part-B: TMT-B) was measured at baseline. RESULTS: At 16 weeks, both groups demonstrated significant increases in usual (P<.05) and fast (P<.05) walking speed, while there was no significant difference in increases between the groups. There was only 1 significant change in lower limb muscle strength over time (non-fractured side) between the groups, such that PUSH did better (mean: 4.33%, 95% confidence interval:1.43%-7.23%). The increase in usual and fast walking speed correlated with the baseline Trail-making Test-B score (r=-0.371, P=.037) and improved muscle strength in the fractured limb (r=0.446, P=.001), respectively. CONCLUSION: Gait speed improved in both home-based multicomponent physical therapy programs in older adults after hip fracture surgery. Muscle strength of the non-fractured limb improved in the group receiving specific physical therapy training. Specific interventions targeting modifiable factors such as muscle strength and cognitive performance may assist gait recovery after hip fracture surgery.

Rehabilitation Outcomes among Frail Older Adults in the United States.

BACKGROUND: Current rehabilitation care paradigms are not well aligned with the needs of frail older adults, but the resultant impact on rehabilitation outcomes is unclear. Understanding how frailty may impact rehabilitation outcomes, and understanding some of the underlying mechanisms, may help inform payment policy changes. DESIGN: This study was a cross-sectional analysis of data from Round 5 of the National Health and Aging and Trends Study (NHATS). We identified older adults who had completed one or more episodes of rehabilitation care and used a validated 5-item NHATS Fried Frailty scale to categorize patients as frail (3/5 or more) or non-frail (≤2/5). We then evaluated the association between frailty status and three key patient outcomes: (1) achievement of rehabilitation goals, (2) functional improvement during rehabilitation episodes, and (3) discontinuation of therapy after exhausting insurance benefits. Lastly, we used multivariable, survey-weighted logistic regression models to estimate adjusted relationships between frailty and rehabilitation outcomes. RESULTS: An estimated 5.6 million survey-weighted older adults in the United States (95% CI 5.1 to 6.0 million) completed an episode of rehabilitation in the past year, an estimated 1,271,290 (95% CI 921,758 to 1,620,822; weighted: 22.8%) of whom were frail. Frail rehabilitation recipients were generally older, had a greater comorbidity burden, and had a higher prevalence of dementia. In adjusted models, frailty was associated with poorer functional outcomes, a lower probability of meeting rehabilitation goals and a greater likelihood of exhausting rehabilitation insurance benefits. CONCLUSIONS: Exercise is a well-supported intervention for the management of frailty, but our results suggest that frail older adults are not getting the volume or intensity of rehabilitation treatment needed to maximally improve outcomes-in part due to limited payer coverage of rehabilitation services in the United States.

Geriatric Vulnerabilities Among Obese Older Adults With and Without Sarcopenia: Findings From a Nationally Representative Cohort Study.

BACKGROUND AND PURPOSE: Sarcopenic obesity is associated with loss of independence among older adults, but the epidemiology of sarcopenic obesity and associated geriatric vulnerabilities are poorly understood. Thus, our objectives were to: (1) estimate the prevalence of older adults with sarcopenic obesity and (2) examine rates of geriatric vulnerabilities among obese older adults, with and without sarcopenia. METHODS: A nationally representative sample of 1600 community-dwelling older adults 65 years and older with obesity and documented measures of muscle function from the National Health and Aging Trends Study (NHATS) was identified as sarcopenic using sex-adjusted grip strength and Short Physical Performance Battery scores. Differences in the prevalence of geriatric vulnerabilities (including pain, depression, disability, and social isolation) were compared between obese older adults with and without sarcopenia. RESULTS AND DISCUSSION: Among obese older adults, 18% (n = 318/1600) were sarcopenic. After adjusting for age and sex, sarcopenic obese older adults had 3.7 times the odds of having 2 or more comorbid conditions (odds ratio [OR] = 3.7; 95% CI 2.2-5.0) and 6.4 times the odds of being frail (OR = 6.4; 95% CI 4.4-9.5) as compared with nonsarcopenic obese older adults. Sarcopenic obese older adults were also more likely to have 1 or more activities of daily living disabilities (OR = 3.7; 95% CI 2.5-5.4), be socially isolated (OR = 2.1; 95% CI 1.3-3.2), and report activity-limiting pain (OR = 2.0; 95% CI 1.5-2.7) as compared with nonsarcopenic obese older adults. These findings, in a nationally representative cohort, suggest obese older adults who are sarcopenic have higher rates of geriatric vulnerabilities that could impact delivery and outcomes of exercise and nutrition interventions. CONCLUSIONS: Concomitant obesity and sarcopenia are associated with higher rates of geriatric vulnerabilities among a nationally representative sample of older adults. More comprehensive interventions, beyond exercise and diet modifications, may be necessary to additionally address these newly identified social and physiological risks.

Impact of psychological resilience on walking capacity in older adults following hip fracture.

BACKGROUND: Community-dwelling older adults experiencing hip fracture often fail to achieve adequate walking capacity following surgery and rehabilitation. Effects of psychological factors on post-fracture walking capacity are poorly understood. Accordingly, this paper investigates effects of psychological resilience on observed walking capacity measures in older adults following hip fracture, controlling for important covariates. METHODS: Data were drawn from the Community Ambulation Project, a clinical trial of 210 community-dwelling adults aged ≥60 years who experienced a minimal trauma hip fracture and were randomized to one of two 16-week home-based physical therapist-guided interventions. Psychological resilience was measured at study baseline using the 6-item Brief Resilience Scale (BRS); scores were classified into groups in order to distinguish levels of self-reported resilience. Walking capacity was assessed at study baseline and 16 weeks later using 4-Meter Gait Speed (4MGS), 50-Foot Walk Test (50FWT), and 6-Minute Walk Distance (SMWD). In multivariate analyses of covariance in which 16-week follow-up values of each walking measure were outcomes, covariates included clinical trial arm, gender, age, and baseline values of: walking measure corresponding to the outcome; body mass index; depressive symptom severity; degree of psychological optimism; cognitive status; informal caregiver need; and days from hospital admission to randomization. RESULTS: Increases between baseline and 16 weeks later in mean gait speed in meters/sec (m/s) and walking distance in meters (m) in 4MGS, 50FWT and SMWD were 0.06 m/s (p = 0.061), 0.11 m/s (p < 0.01), and 25.5 m (p = 0.056) greater, respectively, in the most resilient BRS group compared to the least resilient BRS group. CONCLUSION: Higher levels of psychological resilience were associated with greater walking speed and distance. Psychological resilience represents a potentially clinically important pathway and intervention target, toward the goal of improving walking capacity among older adults known to have substantial residual disability following hip fracture.

Using Treatment Fidelity Measures to Understand Walking Recovery: A Secondary Analysis From the Community Ambulation Project.

OBJECTIVES: Physical therapist intervention studies can be deemed ineffective when, in fact, they may not have been delivered as intended. Measurement of treatment fidelity (TF) can address this issue. The purpose of this study was to describe TF of a home-based intervention, identify factors associated with TF, and examine whether components of TF were associated with the outcome of change in 6-minute walk distance (∆6MWD). METHODS: This is a secondary analysis of community-dwelling hip fracture participants who completed standard therapy and were randomly assigned to the active intervention (Push). Push was 16 weeks of lower extremity strengthening, function, and endurance training. TF was defined as delivery (attendance rate, exercise duration) and receipt (progression in training load, heart rate reserve [HRR] during endurance training, and exercise position [exercise on floor]). The outcome was ∆6MWD. Independent variables included baseline (demographic and clinical) measures. Descriptive statistics were calculated; linear and logistic regressions were performed. RESULTS: Eighty-nine participants were included in this analysis; 59 (66%) had attendance of 75% or greater. Participants walked for 20 minutes or more for 78% of sessions. The average training load increased by 22%; the mean HRR was 35%; and 61 (69%) participants exercised on the floor for at least 75% of sessions. Regression analyses showed that a higher body mass index and greater baseline 6MWD were related to components of TF; 4 out of 5 components of TF were significantly related to ∆6MWD. The strongest TF relationship showed that those who exercised on the floor improved by 62 m (95% CI = 31-93 m) more than those who did not get on the floor. CONCLUSIONS: Measures of TF should extend beyond attendance rate. This analysis demonstrates how measures of TF, including program attendance, progression in training load, endurance duration, and exercising on the floor were significantly related to improvement in 6MWD in participants post hip fracture. IMPACT: This careful analysis of treatment fidelity assured that the intervention was delivered and received as intended. Analysis of data from a large trial with participants after hip fracture showed that regular attendance, frequent endurance training for 20 minutes, increases in lower extremity training loads, and exercising on the floor were associated with improvements in the outcome of 6-minute-walk distance. The strongest association with improvement was exercising on the floor.

Comparison of Lateral Perturbation-Induced Step Training and Hip Muscle Strengthening Exercise on Balance and Falls in Community-Dwelling Older Adults: A Blinded Randomized Controlled Trial.

BACKGROUND: This factorial, assessor-blinded, randomized, and controlled study compared the effects of perturbation-induced step training (lateral waist-pulls), hip muscle strengthening, and their combination, on balance performance, muscle strength, and prospective falls among older adults. METHODS: Community-dwelling older adults were randomized to 4 training groups. Induced step training (IST, n = 25) involved 43 progressive perturbations. Hip abduction strengthening (HST, n = 25) utilized progressive resistance exercises. Combined training (CMB, n = 25) included IST and HST, and the control performed seated flexibility/relaxation exercises (SFR, n = 27). The training involved 36 sessions for a period of 12 weeks. The primary outcomes were the number of recovery steps and first step length, and maximum hip abduction torque. Fall frequency during 12 months after training was determined. RESULTS: Overall, the number of recovery steps was reduced by 31% and depended upon the first step type. IST and CMB increased the rate of more stable single lateral steps pre- and post-training than HST and SFR who used more multiple crossover and sequential steps. The improved rate of lateral steps for CMB exceeded the control (CMB/SFR rate ratio 2.68). First step length was unchanged, and HST alone increased hip torque by 25%. Relative to SFR, the fall rate ratios (falls/person/year) [95% confidence interval] were CMB 0.26 [0.07-0.90], IST 0.44 [0.18-1.08], and HST 0.30 (0.10-0.91). CONCLUSIONS: Balance performance through stepping was best improved by combining perturbation and strength training and not strengthening alone. The interventions reduced future falls by 56%-74% over the control. Lateral balance perturbation training may enhance traditional programs for fall prevention.

Neurocognitive measures predict voluntary stepping performance in older adults post-hip fracture.

BACKGROUND: Hip fracture is a debilitating injury, especially in older adults. The purpose of this study was to determine the relationships between Trail-Making test performance and parameters of the choice stepping reaction time test in community-dwelling older adults after hip fracture. METHODS: Twenty-four older adults post-hip fracture repair participated in an ancillary study for physical therapy interventions. Measures included Trail-Making test (Parts A & B) scores, movement time (time from foot liftoff to touchdown), step speed, reaction time (time from cue to foot liftoff), and total response time (time from step cue to touchdown) in the forward and lateral directions. Paired t-tests and multiple linear regressions were used for analysis. FINDINGS: Significant differences were found in movement time, speed and reaction time between limbs in the lateral direction, and in movement and reaction time in the forward direction. Trails A predicted step speed, reaction time and total response time for the fractured limb in the lateral direction, as well as reaction time and total response time in the forward direction. However, Trails A could not predict performance for the non-fractured limb. Trails B predicted stepping performance for both limbs in the forward and lateral directions. INTERPRETATION: Trails A correlated with the fractured limb's ability to perform the choice stepping test, but not in the non-fractured limb. Meanwhile, Trails B correlated with stepping performance in both limbs, suggesting those with poorer executive function have a lower protective stepping capability and may be at a higher risk for future falls and injury.

Acoustic pre-stimulation modulates startle and postural reactions during sudden release of standing support surface in aging.

Falls contribute to injuries and reduced level of physical activity in older adults. During falls, the abrupt sensation of moving downward triggers a startle-like reaction that may interfere with protective response movements necessary to maintain balance. Startle reaction could be dampened by sensory pre-stimulation delivered immediately before a startling stimulus. This study investigated the neuromodulatory effects of pre-stimulation on postural/startle responses to drop perturbations of the standing support surface in relation to age. Ten younger and 10 older adults stood quietly on an elevated computer-controlled moveable platform. At an unpredictable time, participants were dropped vertically to elicit a startle-like response. Reactive drop perturbation trials without a pre-stimulus (control) were alternated with trials with acoustic pre-stimulus tone (PSI). A two-way mixed design analysis of variance comparing condition (control vs. PSI) X group (younger vs. older) was performed to analyze changes in muscle activation patterns, ground reaction force, and joint angular displacements. Compared to younger adults, older adults showed lower neck muscle electromyography amplitude reduction rate and incidence of response. Peak muscle activation in neck, upper arm, and hamstring muscles were reduced during PSI trials compared to control trials in both groups (p < 0.05). In addition, knee and hip joint flexion prior to ground contact was reduced in PSI trials compared to control (p < 0.05). During post-landing balance recovery, increased knee and hip flexion displacement and time to peak impact force were observed in PSI trials compared to control condition (p < 0.05). PSI reduced startle-induced muscle activation at proximal body segments and likely decreased joint flexion during abrupt downward vertical displacement perturbations of the body. Older adults retained the ability to modulate startle and postural responses but their neuromodulatory capacity was reduced compared with younger adults. Further research on the potential of applying PSI as a possible therapeutic tool to reduce the risk of fall-related injury is needed.

Effect of a Multicomponent Home-Based Physical Therapy Intervention on Ambulation After Hip Fracture in Older Adults: The CAP Randomized Clinical Trial.

Importance: Disability persists after hip fracture in older persons. Current rehabilitation may not be sufficient to restore ability to walk in the community. Objective: To compare a multicomponent home-based physical therapy intervention (training) with an active control on ability to walk in the community. Design, Setting, and Participants: Parallel, 2-group randomized clinical trial conducted at 3 US clinical centers (Arcadia University, University of Connecticut Health Center, and University of Maryland, Baltimore). Randomization began on September 16, 2013, and ended on June 20, 2017; follow-up ended on October 17, 2017. Patients aged 60 years and older were enrolled after nonpathologic, minimal trauma hip fracture, if they were living in the community and walking without human assistance before the fracture, were assessed within 26 weeks of hospitalization, and were not able to walk during daily activities at the time of enrollment. A total of 210 participants were randomized and reassessed 16 and 40 weeks later. Interventions: The training intervention (active treatment) (n = 105) included aerobic, strength, balance, and functional training. The active control group (n = 105) received transcutaneous electrical nerve stimulation and active range-of-motion exercises. Both groups received 2 to 3 home visits from a physical therapist weekly for 16 weeks; nutritional counseling; and daily vitamin D (2000 IU), calcium (600 mg), and multivitamins. Main Outcomes and Measures: The primary outcome (community ambulation) was defined as walking 300 m or more in 6 minutes at 16 weeks after randomization. The study was designed to test a 1-sided hypothesis of superiority of training compared with active control. Results: Among 210 randomized participants (mean age, 80.8 years; 161 women [76.7%]), 197 (93.8%) completed the trial (187 [89.0%] by completing the 6-minute walk test at 16 weeks and 10 [4.8%] by adjudication of the primary outcome). Among these, 22 of 96 training participants (22.9%) and 18 of 101 active control participants (17.8%) (difference, 5.1% [1-sided 97.5% CI, -∞ to 16.3%]; 1-sided P = .19) became community ambulators. Seventeen training participants (16.2%) and 15 control participants (14.3%) had 1 or more reportable adverse events during the intervention period. The most common reportable adverse events reported were falls (training: 6 [5.7%], control: 4 [3.8%]), femur/hip fracture (2 in each group), pneumonia (training: 2, control: 0), urinary tract infection (training: 2, control: 0), dehydration (training: 0, control: 2), and dyspnea (training: 0, control: 2). Conclusions and Relevance: Among older adults with a hip fracture, a multicomponent home-based physical therapy intervention compared with an active control that included transcutaneous electrical nerve stimulation and active range-of-motion exercises did not result in a statistically significant improvement in the ability to walk 300 m or more in 6 minutes after 16 weeks. Trial Registration: ClinicalTrials.gov Identifier: NCT01783704.

Role of Hip Abductor Muscle Composition and Torque in Protective Stepping for Lateral Balance Recovery in Older Adults.

OBJECTIVES: To examine differences in hip abductor strength and composition between older adults who primarily use medial step versus cross-step recovery strategies to lateral balance perturbations. DESIGN: Cross-sectional. SETTING: University research laboratory. PARTICIPANTS: Community-dwelling older adults (N=40) divided into medial steppers (n=14) and cross-steppers (n=26) based on the first step of balance recovery after a lateral balance perturbation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Computed tomography scans to quantify lean tissue and intramuscular adipose tissue (IMAT) areas in the hip abductor, hip abductor isokinetic torque, and first step length. RESULTS: Medial steppers took medial steps in 71.1% of trials versus 4.6% of trials with cross-steps. The cross-steppers when compared with medial steppers, had lower hip abductor IMAT (24.7±0.7% vs 29.9±2.8%; P<.05), greater abductor torque (63.3±3.6Nm vs 48.4±4.1Nm; P<.01), and greater normalized first step length (.75±.03 vs .43±.08; P<.001). There was no difference in hip abductor lean tissue between the groups (P>.05). CONCLUSIONS: Our findings suggest that older adults who initially use a medial step to recover lateral balance have lower hip abductor torque and may be less able to execute a biomechanically more stable cross-step. This may be related to increased IMAT levels. Assessments and interventions for enhancing balance and decreasing fall risk should take the role of the hip abductor into account.

Kinematic and behavioral analyses of protective stepping strategies and risk for falls among community living older adults.

BACKGROUND: Protective stepping evoked by externally applied lateral perturbations reveals balance deficits underlying falls. However, a lack of comprehensive information about the control of different stepping strategies in relation to the magnitude of perturbation limits understanding of balance control in relation to age and fall status. The aim of this study was to investigate different protective stepping strategies and their kinematic and behavioral control characteristics in response to different magnitudes of lateral waist-pulls between older fallers and non-fallers. METHODS: Fifty-two community-dwelling older adults (16 fallers) reacted naturally to maintain balance in response to five magnitudes of lateral waist-pulls. The balance tolerance limit (BTL, waist-pull magnitude where protective steps transitioned from single to multiple steps), first step control characteristics (stepping frequency and counts, spatial-temporal kinematic, and trunk position at landing) of four naturally selected protective step types were compared between fallers and non-fallers at- and above-BTL. FINDINGS: Fallers took medial-steps most frequently while non-fallers most often took crossover-back-steps. Only non-fallers varied their step count and first step control parameters by step type at the instants of step initiation (onset time) and termination (trunk position), while both groups modulated step execution parameters (single stance duration and step length) by step type. Group differences were generally better demonstrated above-BTL. INTERPRETATION: Fallers primarily used a biomechanically less effective medial-stepping strategy that may be partially explained by reduced somato-sensation. Fallers did not modulate their step parameters by step type at first step initiation and termination, instances particularly vulnerable to instability, reflecting their limitations in balance control during protective stepping.

Monitoring 6-month trajectory of grip strength improves the prediction of long-term change in grip strength in disabled older women.

BACKGROUND: This study aims to assess the degree and heterogeneity of decline in grip strength in the short term (6 months) and the clinical relevance of short-term decline to long-term decline (2.5 years) in grip strength in disabled older women. METHODS: Eighty-four community-dwelling disabled women aged 65 years or older were evaluated on a weekly basis over 6 months, followed by an additional five semi-annual visits for a total follow-up of 3 years. The study outcome is maximum isometric handgrip strength in the nondominant hand. Linear random effects models were used to characterize population- as well as individual-level change in grip strength over time. RESULTS: In the weekly assessments over the initial 6 months, individual-level short-term change in grip strength was detectable (mean = -0.12 kg/month; p = .06), heterogeneous (range: -2.03 ± 0.95 kg/month), and independent of absolute grip strength at baseline (mean = 18.4 kg). Additionally, among women with grip strength greater than 16.7 kg at baseline, the long-term rate of decline in grip strength was accelerated by 0.15 kg/year (p = .014) for every 0.5 standard deviation (0.25 kg/month) increase in the short-term rate of decline. The baseline absolute grip strength, however, was not significantly associated with the long-term rate of decline (correlation = -0.36, p = .105). CONCLUSIONS: Our findings suggest that short-term change in grip strength is detectable and meaningful for disabled older women and it is the individual's past trajectory of grip strength relative to her current strength level, not her current absolute strength per se, that is important for predicting future strength decline.

Hip but not thigh intramuscular adipose tissue is associated with poor balance and increased temporal gait variability in older adults.

BACKGROUND: Intramuscular adipose tissue (IMAT) of the lower extremity is a strong negative predictor of mobility function. Variability in temporal gait factors is another important predictor of mobility function. The purpose of this study was to examine the relationships between IMAT in the hip and thigh muscles, balance, and temporal gait variability in older adults. METHODS: Forty-eight healthy community dwelling older adults (74 +/- 1 year) underwent a CT scan to quantify IMAT in the gluteus maximus (Gmax), gluteus medius/minimus (Gmed/min), hamstrings, vastus lateralis, and adductor muscles. Temporal Gait measures were collected on a GAITRite walkway and gait variability was determined by calculating intraindividual standard deviations. Individuals were divided by tertiles of temporal gait variability into categories of high, medium, and low variability. Differences in the IMAT of the hip abductors were calculated for those with high and low gait variability and partial correlations for gait variability and all muscle composition measures were determined for all variables with normalized gait speed as a covariate. RESULTS: Gmed/min IMAT was greater in those with higher gait variability compared to those with lower gait variability (p<0.05). Gmed/min IMAT was related to stride width variability (r=0.30, p<0.05). Gmax IMAT was also related to time variability of swing (r=0.42), stance (r=0.26), double limb support (r=0.43), double support loading (r=0.44), and double support unloading (r=0.50) (all p<0.05). CONCLUSION: Increased IMAT in the proximal hip muscles, particularly the hip abductors, was associated with increased gait variability and poorer balance. These findings may have implications for the assessment and treatment of balance and falls such that interventions for enhancing balance and mobility among older individuals should take into account the importance of gluteal muscle composition.

Gluteal muscle composition differentiates fallers from non-fallers in community dwelling older adults.

BACKGROUND: Impaired balance, loss of mobility and falls are major problems associated with changes in muscle in older adults. However, the extent to which muscle composition and related performance measures for different lower limb muscles are associated with falls in older individuals is unclear. This study evaluated lower limb muscle attenuation, intramuscular adipose tissue (IMAT) infiltration and muscle performance in older fallers and non-fallers. METHODS: For this cross-sectional study, fifty-eight community dwelling older individuals (>65 years) were classified into fallers (n = 15) or non-fallers (n = 43). Computed tomography (CT) was used to determine muscle attenuation and intramuscular adipose tissue (IMAT) of multiple thigh and hip muscles. Muscle performance was assessed with isokinetic dynamometry. RESULTS: For both groups, Rectus Femoris showed the highest muscle attenuation and lowest IMAT infiltration, and Gluteus Maximus and Gluteus Medius/Minimus muscles had the lowest muscle attenuation and highest IMAT infiltration. Fallers exhibited lower muscle attenuation and higher IMAT infiltration than non-faller participants in most muscles, where the gluteal muscles were the most affected (p < 0.05). Fallers also showed a lower peak hip abduction torque (p < 0.05). There were significant associations (r = 0.31 to 0.53) between joint torques and muscle composition, with the strongest associations between Gluteus Medius/Minimus and hip abduction strength. CONCLUSIONS: While fallers were generally differentiated from non-fallers by muscle composition, the most affected muscles were the proximal gluteal muscles of the hip joint accompanied by lower hip abduction strength, which may contribute to impaired balance function and increased risk for falls.

Simple biologically informed inflammatory index of two serum cytokines predicts 10 year all-cause mortality in older adults.

BACKGROUND: Individual measurements of inflammation have been utilized to assess adverse outcomes risk in older adults with varying degrees of success. This study was designed to identify biologically informed, aggregate measures of inflammation for optimal risk assessment and to inform further biological study of inflammatory pathways. METHODS: In total, 15 nuclear factor-kappa B-mediated pathway markers of inflammation were first measured in baseline serum samples of 1,155 older participants in the InCHIANTI population. Of these, C-reactive protein, interleukin-1-receptor antagonist, interleukin-6, interleukin-18, and soluble tumor necrosis factor-α receptor-1 were independent predictors of 5-year mortality. These five inflammatory markers were measured in baseline serum samples of 5,600 Cardiovascular Health Study participants. A weighted summary score, the first principal component summary score, and an inflammation index score were developed from these five log-transformed inflammatory markers, and their prediction of 10-year all-cause mortality was evaluated in Cardiovascular Health Study and then validated in InCHIANTI. RESULTS: The inflammation index score that included interleukin-6 and soluble tumor necrosis factor-α receptor-1 was the best predictor of 10-year all-cause mortality in Cardiovascular Health Study, after adjusting for age, sex, education, race, smoking, and body mass index (hazards ratio = 1.62; 95% CI: 1.54, 1.70) compared with all other single and combined measures. The inflammation index score was also the best predictor of mortality in the InCHIANTI validation study (hazards ratio 1.33; 95% CI: 1.17-1.52). Stratification by sex and CVD status further strengthened the association of inflammation index score with mortality. CONCLUSION: A simple additive index of serum interleukin-6 and soluble tumor necrosis factor-α receptor-1 best captures the effect of chronic inflammation on mortality in older adults among the 15 biomarkers measured.