Comparison of a Multi-Component Physical Function Battery to Usual Walking Speed for Assessing Lower Extremity Function and Mobility Limitation in Older Adults

OBJECTIVES

To compare a composite measure of physical function that comprises locomotor and non-locomotor tests (i.e., the Mobility Battery Assessment (MBA)) with traditional measures of mobility (4-m usual gait speed (UGS), six-minute walk (6MW) gait speed, and short physical performance battery (SPPB) score) for assessing lower extremity function and discriminating community dwelling older adults with and without mobility limitations.

DESIGN

Cross-sectional, observational study.

SETTING

Laboratory-based.

PARTICIPANTS

89 community-dwelling older adults (74.9±6.7).

MEASUREMENTS

Using principal component analysis we derived an MBA score for 89 community-dwelling older adults, and quantified 4-m UGS, 6MW gait speed, and SPPB score. The MBA score was based on five lab-based tests. We also quantified self-reported lower extremity function/mobility using the Neuro-QOL Lower Extremity Function-Mobility instrument. Based on this data a continuous score was derived and subjects were classified as "mobility limited" or "non-mobility limited". Correlations between the mobility measures and the Neuro-QOL score were calculated, and ROC curves were constructed to determine the AUC for the mobility measures ability to predict mobility limitations.

RESULTS

The MBA had the largest AUC (0.92) for discriminating mobility limitations and exhibited the strongest correlation (0.73) with the Neuro-QOL Lower Extremity Function-Mobility Scale. The worst performing predictors were the 4-meter UGS and stair climb power both with an AUC of 0.8 for discriminating mobility limitations, and a low correlation with Neuro-QOL Lower Extremity Function Scale of 0.39 and 0.46, respectively.

CONCLUSION

The MBA score moderately improves the magnitude of correlation and discrimination of mobility limitation in older adults than singular, standard tests of mobility.

Higher dose of resveratrol elevated cardiovascular disease risk biomarker levels in overweight older adults - A pilot study

Older adults are at high risk of developing cardiovascular disease (CVD). Pre-clinical studies indicate that resveratrol (RSV), a polyphenol commonly found in grapes and red wine, may help prevent development of CVD. Based on our previous reports where the 300 mg and 1000 mg doses appeared safe and improved psychomotor function in a dose-dependent manner, our hypothesis was that RSV would reduce biomarkers of CVD risk in overweight, but otherwise healthy older adults and that 1000 mg would lower CVD biomarkers >300 mg. This analysis was performed on samples from older participants (65 years and older) who were randomized to a 90 day RSV treatment with 300 mg (n = 10), 1000 mg (n = 9) or placebo (n = 10). We measured levels of CVD risk biomarkers i.e. oxidized low-density lipoprotein (oxLDL), soluble E-selectin-1 (sE-selectin), soluble Intercellular Adhesion Molecule-1 (sICAM-1), Soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), total plasminogen activator inhibitor (tPAI-1). Statistical significance was set at p < 0.05. Both sVCAM-1 and tPAI increased significantly more in the 1000 mg vs. 300 mg and placebo groups. Other biomarkers (300 mg vs. 1000 mg vs. placebo: oxLDL, sEselectin-1 and sICAM-1) followed the same trend toward higher levels in the 1000 mg group compared to the 300 mg and placebo groups, without reaching statistical significance. This pilot project suggests that a higher dose of RSV may increase the levels of CVD risk biomarkers in overweight older adults. Given no change in the CVD risk biomarkers in response to a lower dose, future studies should test the effects of different doses of RSV to evaluate potential detrimental effects of higher doses on CVD biomarkers and measures of cardiovascular function in older adults at risk for CVD.

Impact of Baseline Fatigue on a Physical Activity Intervention to Prevent Mobility Disability

OBJECTIVES

Our aim was to examine the impacts of baseline fatigue on the effectiveness of a physical activity (PA) intervention to prevent major mobility disability (MMD) and persistent major mobility disability (PMMD) in participants from the Lifestyle Interventions and Independence for Elders (LIFE) study.

DESIGN

Prospective cohort of individuals aged 65 years or older undergoing structured PA intervention or health education (HE) for a mean of 2.6 years.

SETTING

LIFE was a multicenter eight-site randomized trial that compared the efficacy of a structured PA intervention with an HE program in reducing the incidence of MMD.

PARTICIPANTS

Study participants (N = 1591) at baseline were 78.9 ± 5.2 years of age, with low PA and at risk for mobility impairment.

MEASUREMENTS

Self-reported fatigue was assessed using the modified trait version of the Exercise-Induced Feelings Inventory, a six-question scale rating energy levels in the past week. Responses ranged from 0 (none of the time) to 5 (all of the time). Total score was calculated by averaging across questions; baseline fatigue was based on the median split: 2 or higher = more fatigue (N = 856) and lower than 2 = less fatigue (N = 735). Participants performed a usual-paced 400-m walk every 6 months. We defined incident MMD as the inability to walk 400-m at follow-up visits; PMMD was defined as two consecutive walk failures. Cox proportional hazard models quantified the risk of MMD and PMMD in PA vs HE stratified by baseline fatigue adjusted for covariates.

RESULTS

Among those with higher baseline fatigue, PA participants had a 29% and 40% lower risk of MMD and PMMD, respectively, over the trial compared with HE (hazard ratio [HR] for MMD = .71; 95% confidence interval [CI] = .57-.90; P = .004) and PMMD (HR = .60; 95% CI = .44-.82; P = .001). For those with lower baseline fatigue, no group differences in MMD (P = .36) or PMMD (P = .82) were found. Results of baseline fatigue by intervention interaction was MMD (P = .18) and PMMD (P = .05).

CONCLUSION

A long-term moderate intensity PA intervention was particularly effective at preserving mobility in older adults with higher levels of baseline fatigue. J Am Geriatr Soc 68:619-624, 2020.

Magnitude of and Characteristics Associated With the Treatment of Calcium Channel Blocker-Induced Lower-Extremity Edema With Loop Diuretics

IMPORTANCE

Calcium channel blockers, specifically dihydropyridine calcium channel blockers (DH CCBs, eg, amlodipine), may cause lower-extremity edema. Anecdotal reports suggest this may result in a prescribing cascade, where DH CCB-induced edema is treated with loop diuretics.

OBJECTIVE

To assess the magnitude and characteristics of the DH CCB prescribing cascade.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used a prescription sequence symmetry analysis to assess loop diuretic initiation before and after the initiation of DH CCBs among patients aged 20 years or older without heart failure. Data from a private insurance claims database from 2005 to 2017 was analyzed. Use of loop diuretics associated with initiation of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and other commonly used medications was used as negative controls. Data were analyzed from March 2019 through October 2019.

EXPOSURES

Initiation of DH CCB or negative control medications.

MAIN OUTCOMES AND MEASURES

The temporality of loop diuretic initiation relative to DH CCB or negative control initiation. Secular trend-adjusted sequence ratios (aSRs) with 95% CIs were calculated using data from 360 days before and after initiation of DH CCBs.

RESULTS

Among 1 206 093 DH CCB initiators, 55 818 patients (4.6%) (33 100 [59.3%] aged <65 years; 32 916 [59.0%] women) had a new loop diuretic prescription 360 days before or after DH CCB initiation, resulting in an aSR of 1.87 (95% CI, 1.84-1.90). An estimated 1.44% of DH CCB initiators experienced the prescribing cascade. The aSR was disproportionately higher among DH CCB initiators who were prescribed high doses (aSR, 2.20; 95% CI, 2.13-2.27), initiated amlodipine (aSR, 1.89; 95% CI, 1.86-1.93), were men (aSR, 1.96; 95% CI, 1.91-2.01), and used fewer antihypertensive classes (aSR, 2.55; 95% CI, 2.47-2.64). The evaluation of ACE inhibitors or ARBs as negative controls suggested hypertension progression may have tempered the incidence of the prescribing cascade (aSR for ACE inhibitors and ARBs, 1.27; 95% CI, 1.24-1.29).

CONCLUSIONS AND RELEVANCE

This study found an excessive use of loop diuretics following initiation of DH CCBs that cannot be completely explained by secular trends or hypertension progression. The prescribing cascade was more pronounced among those initially prescribed a high dose of DH CCBs.

EXCURSION FROM HOME AND ECOLOGICAL PAIN IN OLDER ADULTS WITH KNEE PAIN

Background: Pain is an essential factor in limiting life-space mobility. Ecological momentary assessment (EMA) is crucial to understanding pain intensity and frequency. This study evaluated a customized smartwatch app for daily ecological pain reporting and GPS (Global Positioning System) coordinates collection to understand the impact of pain on daily excursion from home in older adults who report knee pain. Methods: Participants (n=14, 73.2 +/- 5.4 yrs, 64% female) wore a smartwatch with a customized app called Patient Reported Outcome of Mood, Pain, and fatigue (PROMPT) for 6.5 (4.0) days. Participants were prompted in their free-living environment about their pain intensity (range 0-10) in the morning, afternoon and evening. Additionally, GPS data were collected at 15 min intervals throughout the day. Geodesic distance was used to calculate the distance from the home address. Daily pain values were binned into high and low levels to compare to maximum daily excursions. Results: Individuals with average daily pain > 2 traveled 4.1 fewer miles than those individuals reporting pain 2 exceeded a distance of 5 miles compared to 17.9% of those individuals reporting pain <= 2 (X2=6.89, p < 0.05). Conclusion: In older adults, higher level of knee pain is associated with a decline in life-space mobility. Using custom designed smartwatch applications provides new opportunity to investigate how pain impacts community mobility.

PERIPHERAL ARTERIAL DISEASE AND SEDENTARY TIME IN OLDER ADULTS

Peripheral artery disease (PAD) is associated with increased rates of physical disability in older adults, yet few interventions exist to reduce this risk. Intermittent claudication, exertional calf symptoms that resolve within 10 minutes of rest, is the classic symptom for PAD, but many people with PAD are absent of these symptoms. Ankle brachial index (ABI) is a non-invasive measure that identifies the presence and severity of lower extremity arterial obstruction due to atherosclerosis. We studied whether abnormal ABI is associated with increased time spent in sedentary behavior in a large sample of community-dwelling older men and women (70-89 years) enrolled in the Lifestyle Interventions and Independence for Elders (LIFE) study. Older adults underwent an ABI test and then wore a tri-axial accelerometer on the hip for up to seven days. Total accumulated sedentary time and sedentary time spent in bout lengths of 10minutes or more, 30 minutes or more, and 60 minutes or more were calculated. ABI values, divided into PAD (<.90, n=156) and non-PAD (0.90 - 1.40, n=960), were evaluated in covariate-adjusted regression models adjusting for age, body mass index, comorbidity presence, gender and smoking. Older adults with PAD had significantly higher total accumulated time spent in sedentary behavior than those without PAD (13.1 minutes per day, p<0.02). No associations were found with longer bout lengths of sedentary time. These results suggest that older adults with PAD accumulate more time in shorter bouts of sedentary behavior. Future interventions may consider targeting short sedentary bout-lengths for reducing PAD symptoms.

WRIST-WORN TRI-AXIAL ACCELEROMETER VALIDATION IN YOUNG, MIDDLE-AGED, AND OLDER ADULTS

Purpose: This study evaluated wrist-worn accelerometers for estimating metabolic intensity and classifying activity types across a wide age spectrum. Methods: Participants (n=141, 67% women, aged 20-89 yrs) performed a battery of 31 common daily activities (e.g. washing dishes, walking) in a standardized laboratory setting. A tri-axial accelerometer was worn on the right wrist during each activity whiel a portable metabolic unit was used to measure oxygen consumption (ml/kg/min), which was converted into metabolic equivalents (METs). Random forest analyses estimated metabolic intensity and classified activity type based on seven data features. Resulting estimates were cross-evaluated on a separate sample of 16 participants who performed a sub-set of activities in their home. Results: In the laboratory setting, mean differences between measured and predicted MET value for sedentary (0.36), lifestyle (0.02) and locomotor (0.30) activities were low, but the 95% limits of agreement ranges were relatively large (+/-1.0, +/-1.8, +/-3.1, respectively). Data features were 85%, 88%, and 71% accurate for identifying sedentary, lifestyle and locomotor activities. Prediction equations had an overall mean difference of 0.19 METs (95% limits of agreement = -1.3 to 1.7) when activities were performed at home. Conclusion: Data features extracted from a wrist worn tri-axial accelerometer provide a moderate-to-high group estimate of metabolic intensity and had modest accuracy in identifying activity types across a variety of daily activities. However, significant between person variations were evident. Additional work is needed to refine wrist-worn accelerometers for estimating physical activity type, intensity, duration and frequency across the age spectrum.

Mitochondrial DNA Sequence Variants Associated With Blood Pressure Among 2 Cohorts of Older Adults

Background

Age‐related changes in blood pressure are associated with a variety of poor health outcomes. Genetic factors are proposed contributors to age‐related increases in blood pressure, but few genetic loci have been identified. We examined the role of mitochondrial genomic variation in blood pressure by sequencing the mitochondrial genome.

Methods and Results

Mitochondrial DNA (mtDNA) data from 1755 participants from the LIFE (Lifestyle Interventions and Independence for Elders) studies and 788 participants from the Health ABC (Health, Aging, and Body Composition) study were evaluated using replication analysis followed by meta‐analysis. Participants were aged ≥69 years, of diverse racial backgrounds, and assessed for systolic blood pressure (SBP), diastolic blood pressure, and mean arterial pressure. After meta‐analysis across the LIFE and Health ABC studies, statistically significant associations of mtDNA variants with higher SBP (m.3197T>C, 16S rRNA; P=0.0005) and mean arterial pressure (m.15924A>G, t‐RNA‐thr; P=0.004) were identified in white participants. Among black participants, statistically significant associations with higher SBP (m.93A>G, HVII; m.16183A>C, HVI; both P=0.0001) and mean arterial pressure (m.16172T>C, HVI; m.16183A>C, HVI; m.16189T>C, HVI; m.12705C>T; all P's<0.0004) were observed. Significant pooled effects on SBP were observed across all transfer RNA regions (P=0.0056) in white participants. The individual and aggregate variant results are statistically significant after multiple comparisons adjustment for the number of mtDNA variants and mitochondrial regions examined.

Conclusions

These results suggest that mtDNA‐encoded variants are associated with variation in SBP and mean arterial pressure among older adults. These results may help identify mitochondrial activities to explain differences in blood pressure in older adults and generate new hypotheses surrounding mtDNA variation and the regulation of blood pressure.

Clinical Trial Registration

URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT01072500 and NCT00116194.

RATINGS OF PERCEIVED EXERTION: PREDICTING MOBILITY DISABILITY AND RESPONSE TO PHYSICAL ACTIVITY IN OLDER ADULTS

Ratings of perceived exertion (RPE) during exercise are linked to several physiological indices and are often elevated in older adults. This study evaluated the association between RPE of walking and incident major mobility disability (MMD) as well as response to a physical activity (PA) program. Older adults (n=1633) at-risk for mobility impairment were randomized to a structured PA or health education (HE) program. During a 400m walk, participants rated exertion as “none”, “light”, “somewhat hard” or “hard”. An MMD event was defined as the inability to complete the 400m walk. Transitions between RPE states and an MMD event—when RPE was not collected— were assessed over the follow-up (every 6 months for an average of 2.6 years). Participants rating their exertion as “hard” at baseline 400m walk had nearly 3-fold higher risk of MMD compared with those rating as “light” (HR: 2.61, 95%CI: 2.19-3.11). During follow-up, the PA group was 25% more likely to transition from “light” to “hard” RPE (1.25, 1.05-1.49), but was 27% (0.73, 0.55 – 0.97) less likely to transition from a “hard” RPE to MMD than the HE group. Additionally, the PA group was more likely to transition from an MMD event to a “hard” RPE (2.09, 1.38-3.17) than the HE group (i.e. recovery). Older adults rating “hard” effort during a standardized walk test were at increased risk of MMD. A structured PA program increased transition from light to hard effort, which may reflect greater capacity to perform the test and increased recovery from an MMD event.

Wearable Technology To Reduce Sedentary Behavior And CVD Risk In Older Adults: A Pilot Randomized Clinical Trial

Background

Physical exercise is associated with decreased cardiovascular disease (CVD) risk, but recent large-scale trials suggest that exercise alone is insufficient to reduce CVD events in high-risk older adults.

Purpose

This pilot randomized clinical trial aimed to collect critical data on feasibility, safety, and protocol integrity necessary to design a fully powered randomized controlled trial (RCT) and evaluate the impact of combining structured exercise with an intervention designed to enhance non-exercise physical activity (EX+NEPA) compared to EX alone.

Methods

Forty participants aged ≥60 years with moderate-to-high risk of coronary heart disease events were randomly assigned to either the EX+NEPA or EX groups and followed for 20 weeks. Both groups underwent a twice-weekly, 8-week center-based exercise intervention with aerobic and resistance exercises. EX+NEPA group also received a wearable activity tracking device along with behavioral monitoring and feedback throughout the study. Study outcomes were evaluated at 8 and 20 weeks.

Results

Data are presented as adjusted mean change of the differences over time with 95% confidence intervals at 20 weeks. Relative to EX, the change in steps/day at 20 weeks was 1994 (-40.27, 4028) higher for EX+NEPA. For sedentary time at close-out, the EX+NEPA group was -6.8 (-45.2, 31.6) min/day relative to EX. The between-group differences for systolic and diastolic blood pressure were -9.9 (-19.6, -0.3) and -1.8 (-6.9, 3.3) mmHg, respectively.

Conclusion

The addition of wearable technology intervention appeared to positively influence daily activity patterns and changes in blood pressure - potentially improving risk factors for CVD. A fully powered randomized trial is needed to ultimately test this hypothesis.

The Influence of Physical Activity and Sedentary Behavior on Living to Age 85 Years Without Disease and Disability in Older Women

Background

Whether physical activity (PA) and sedentary behavior influence the odds of women living to age 85 years without chronic disease or disability is not well described.

Methods

Participants of the Women's Health Initiative (n = 49,612) were categorized based on health status by age 85 years: (i) lived without developing major chronic disease or mobility disability ("healthy"); (ii) lived and developed mobility disability with or without disease; (iii) lived and developed major chronic disease, but not mobility disability; and (iv) died before their 85th birth year. Multinomial logistic regression models that adjusted for covariates such as age, race/ethnicity, and body size estimated associations of self-reported PA and sitting time on developing major disease or mobility disability or dying before age 85 relative to being healthy.

Results

Mean ± SD baseline age was 70.2 ± 3.6 years. Distributions were: 22% healthy, 23% had mobility disability, 26% had major disease, and 29% died. Relative to those with high total PA, the adjusted odds ratios (OR) (confidence intervals [CI]) for mobility disability was 1.6 (1.4-1.7), 1.2 (1.1-1.3), and 1.1 (1.0-1.2) for women with no, low, and moderate total PA, respectively (p-trend < .001). The corresponding covariate-adjusted OR (CI) for mortality was 1.7 (1.5-1.8), 1.2 (1.1-1.3), and 1.0 (1.0-1.1) (p-trend < .001). Total PA was not associated with developing chronic disease before age 85 years. Sitting ≥10 relative to <5 hours per day increased the odds of mobility disability (1.1, CI: 1.0-1.3) and mortality (1.2, CI: 1.0-1.3) prior to age 85 years (p < .001).

Conclusions

Increasing PA to recommended levels and reducing sitting time are modifiable behaviors that may improve healthy aging in older women.

Effect of Losartan and Fish Oil on Plasma IL-6 and Mobility in Older Persons. The ENRGISE Pilot Randomized Clinical Trial

BACKGROUND

Low-grade chronic inflammation, characterized by elevations in plasma Interleukin-6 (IL-6), is an independent risk factor of impaired mobility in older persons. Angiotensin receptor blockers and omega-3 polyunsaturated fatty acids (ω-3) may reduce IL-6 and may potentially improve physical function. To assess the main effects of the angiotensin receptor blocker losartan and ω-3 as fish oil on IL-6 and 400 m walking speed, we conducted the ENRGISE Pilot multicenter randomized clinical trial.

METHODS

The ENRGISE Pilot enrolled participants between April 2016 and June 2017, who participated for 12 months. Participants were aged ≥70 years with mobility impairment, had IL-6 between 2.5 and 30 pg/mL, and were able to walk 400 m at baseline. Participants were randomized in three strata 2 × 2 factorial to: (i) losartan 50-100 mg/d or placebo (n = 43), (ii) fish oil 1,400-2,800 mg/d or placebo (n = 180), and (iii) with both (n = 66).

RESULTS

Two hundred eighty-nine participants were randomized (mean age 78.3 years, 47.4% women, 17.0% black). There was no effect of losartan (difference of means = -0.065 ± 0.116 [SE], 95% confidence interval [CI]: -0.293-0.163, p = .58) or fish oil (-0.020 ± 0.077, 95% CI: -0.171-0.132, p = .80) on the log of IL-6. Similarly, there was no effect of losartan (-0.025 ± 0.026, 95% CI: -0.076-0.026, p = .34) or fish oil (0.010 ± 0.017, 95% CI: -0.025-0.044, p = .58) on walking speed (m/s).

CONCLUSIONS

These results do not support the use of these interventions to prevent mobility loss in older adults at risk of disability with low-grade chronic inflammation.

REGISTRATION

Clinicaltrials.gov NCT02676466.

Voluntary vs Electrically Stimulated Activation in Age-Related Muscle Weakness

This cross-sectional study compares voluntary neural activation of lower extremity muscles in clinically weak older adults vs stronger older adults.

Role of Wearable Accelerometer Devices in Delirium Studies: A Systematic Review

We sought to determine the feasibility of using wearable accelerometer devices for determining delirium effects on patients' physical activity patterns and detecting delirium and delirium subtype.

DATA SOURCES

PubMed, Embase, and Web of Science.

STUDY SELECTION

Screening was performed using predefined search terms to identify original research studies using accelerometer devices for studying physical activity in relation to delirium.

DATA EXTRACTION

Key data were extracted from the selected articles.

DATA SYNTHESIS

Among the 14 studies identified, there were a total of 315 patients who wore accelerometer devices to record movements related to delirium. Eight studies (57.1%) used accelerometer devices to compare the activity of delirious and nondelirious patients. Delirious patients had lower activity levels, lower restlessness index, higher number of daytime immobility minutes, lower mean activity levels during the day, and higher mean activity levels at night. Delirious patients also had lower actual sleep time, lower sleep efficiency, fewer nighttime minutes resting, fewer minutes resting over 24 hours, and smaller change in activity from day to night. Six studies (42.9%) evaluated the feasibility of using accelerometer devices for detection of delirium and its subtype. Variables including number of postural changes during daytime, frequency of ultrashort, short, and continuous movements were significantly different among the nondelirium and the three delirium subtypes.

CONCLUSIONS

The results from the studies using accelerometer devices in studying delirium demonstrate that accelerometer devices can potentially detect the differences between delirious and nondelirious patients, detect delirium, and determine delirium subtype. We suggest the following directions as the next steps for future studies using accelerometer devices for predicting delirium: benchmark studies with longer data collection, larger and more diverse population size, incorporating related factors (e.g., medications), and evaluating delirium subtype and severity.

Effect of Gastric Acid Suppressants on Response to a Physical Activity Intervention and Major Mobility Disability in Older Adults: Results from the Lifestyle Interventions for Elders (LIFE) Study

OBJECTIVES

Proton pump inhibitors (PPIs) and histamine2 receptor antagonists (H2 RAs) are associated with pharmacologic effects that may be detrimental to mobility and response to physical activity. Mobility disability and injurious fall outcomes in PPI and H2 RA users were compared with nonusers in this secondary analysis of data from the Lifestyle Interventions for Elders (LIFE) study.

METHODS

Participants ages 70-89 years were randomized to a physical activity (PA) or successful aging intervention and evaluated by medication use. Confounders included baseline demographic characteristics, physical function, cognitive function, sleep quality, and acid reflux symptoms that were adjusted via propensity score weighting. Outcomes were incident and persistent major mobility disability (MMD and pMMD) and injurious falls. Weighted proportional hazard models evaluated independent and interaction effects of PPIs and H2 RAs.

RESULTS

No interaction was found between PPIs and H2 RAs and the PA intervention. Drug use associations were significant for H2 RAs (hazard ratio [HR] 1.74 [95% confidence interval [CI] 1.12-2.68]) and PPIs (HR 1.32 [95% CI 1.02-1.70]) compared with nonusers for pMMD. PPIs were associated with increased injurious falls compared with nonusers (HR 1.44 [95% CI 1.06-1.96]). Pooling of data from the H2 RA and PPI exposure groups showed a 26% increase in MMD (HR 1.26 [95% CI 1.07-1.48]), a 44% increase in pMMD (HR 1.44 [95% CI 1.16-1.77]), and a 48% increase in injurious falls (HR 1.48 [95% CI 1.15-1.91]) compared with nonusers. All direct comparisons between PPIs and H2 RAs were nonsignificant.

CONCLUSIONS

Compared with nonusers, participants using either PPIs or H2 RAs had an increased risk of MMD, pMMD, and injurious falls. It is not known if these effects are related to the individual pharmacology of each medication, reduced acid secretion, or the underlying disease state. Further study is required to determine causality.

A comparison of accelerometry analysis methods for physical activity in older adult women and associations with health outcomes over time

This study compared five different methods for analyzing accelerometer-measured physical activity (PA) in older adults and assessed the relationship between changes in PA and changes in physical function and depressive symptoms for each method. Older adult females (N = 144, M_age = 83.3 ± 6.4yrs) wore hip accelerometers for six days and completed measures of physical function and depressive symptoms at baseline and six months. Accelerometry data were processed by five methods to estimate PA: 1041 vertical axis cut-point, 15-second vector magnitude (VM) cut-point, 1-second VM algorithm (Activity Index (AI)), machine learned walking algorithm, and individualized cut-point derived from a 400-meter walk. Generalized estimating equations compared PA minutes across methods and showed significant differences between some methods but not others; methods estimated 6-month changes in PA ranging from 4 minutes to over 20 minutes. Linear mixed models for each method tested associations between changes in PA and health. All methods, except the individualized cut-point, had a significant relationship between change in PA and improved physical function and depressive symptoms. This study is among the first to compare accelerometry processing methods and their relationship to health. It is important to recognize the differences in PA estimates and relationship to health outcomes based on data processing method. Abbreviation: Machine Learning (ML); Short Physical Performance Battery (SPPB); Center of Epidemiologic Studies Depression Scale (CES-D); Physical Activity (PA); Activity Index (AI); Activities of Daily Living (ADL).

Translating the Lifestyle Interventions and Independence for Elders Clinical Trial to Older Adults in a Real-World Community-Based Setting

BACKGROUND

The Lifestyle Interventions and Independence for Elders (LIFE) clinical trial demonstrated that a structured program of physical activity (PA) reduced mobility-disability in older adults by up to 28%. It remains unknown whether the benefits of LIFE PA can be translated to older adults at risk for mobility-disability in real-world community-based settings. To address this knowledge gap, we conducted the ENhancing independence using Group-based community interventions for healthy AGing in Elders (ENGAGE) pilot study and examined the safety, feasibility, and preliminary effectiveness of translating LIFE PA to a community-based senior center.

METHODS

Forty older adults with severe lower extremity functional limitations (age: 76.9 ± 7.3 years; body mass index: 32.7 ± 8 kg/m2; 85% female; short physical performance battery score: 6.3 ± 2.2) were randomized to 24 weeks of PA or a health education control intervention.

RESULTS

Community-based PA was safe (serious adverse events: PA vs health education, 0:2; nonserious adverse events: PA vs health education, 3:1) and participants successfully adhered to the PA intervention (65.2%). Compared to health education, PA participants who attended ≥25% of scheduled visits had meaningful and sustained short physical performance battery improvements at follow-up (between group short physical performance battery score differences: ~0.7 units).

CONCLUSIONS

ENGAGE has demonstrated the preliminary safety, feasibility, and effectiveness of LIFE PA in a real-world community-based setting. Larger-scale translational studies are needed to further disseminate the benefits of LIFE PA to vulnerable older adults in a variety of community-based settings.

Maintenance of Physical Function 1 Year After Exercise Intervention in At-Risk Older Adults: Follow-up From the LIFE Study

Background

Structured physical activity interventions delay the onset of disability for at-risk older adults. However, it is not known if at-risk older adults continue to participate in physical activity or maintain mobility benefits after cessation of structured intervention.

Methods

One thousand six hundred and thirty-five sedentary men and women aged 70-89 years with Short Physical Performance Battery (SPPB) scores of 9 or less and able to walk 400 m were randomized to a structured, moderate-intensity physical activity (PA) program consisting of center-based (twice/week) and home-based (three to four times per week) aerobic, resistance, and flexibility training or a health education (HE) program combined with upper extremity stretching.

Results

Most of the participants (88% of HE and 87% of PA) returned for a follow-up visit (POST) 1 year after cessation of formal intervention. The HE group reported about 1-hour less activity per week than the PA group at end of intervention (LAST TRIAL; -68.9; 95% confidence interval [CI] = -86.5 to -51.3) but similar weekly activity at POST (-13.5; 95% CI = -29.5 to 2.47). SPPB did not differ between the two groups at LAST TRIAL (-0.06; 95% CI = -0.31 to 0.19) nor POST (-0.18; 95% CI = -0.45 to 0.088).

Conclusions

Although sedentary at-risk older adults increased their physical activity during a structured physical activity intervention, they did not continue at this level following the cessation of intervention. Future exercise interventions need to include novel methods to support older adults in continued physical activity following structured interventions.

A Comparison of Self-report Indices of Major Mobility Disability to Failure on the 400-m Walk Test: The LIFE Study

Background

The objective assessment of major mobility disability (objective MMD) by a 400-m walk test (400 MWT) is important but not always practical. Previous research on the relationship between self-reported MMD (SR MMD) and objective MMD is sparse and limited to cross-sectional data.

Methods

We evaluated agreement between SR MMD and objective MMD using longitudinal data from the Lifestyle Interventions for Elders (LIFE) study. The SR MMD indices were defined based on having a lot of difficulty or inability to walk a quarter of a mile (SR-1/4MILE), walk several blocks (SR-BLOCKS), and climb one flight of stairs (SR-STAIRS).

Results

Using objective MMD as the gold standard, SR-1/4MILE and SR-BLOCKS had relatively low sensitivity (around 0.4) and high specificity (around 0.9) for prevalence. Their overall sensitivity and specificity for cumulative incident objective MMD were approximately 0.6 and 0.8, respectively. While the annual probability of staying MMD free was similar for objective MMD, SR-1/4MILE, and SR-BLOCKS (90% for all), the probability of recovering from SR MMD was higher (50%) than that of objective MMD (22%). The development of objective MMD (439 events), SR-1/4MILE (356 events), and SR-BLOCKS (379 events) had a similar trajectory over time with substantially overlapping survival curves. SR-STAIRS generally did not agree well with objective MMD. Incorporating SR-STAIRS with either SR-1/4MILE or SR-BLOCKS did not significantly improve the agreement between SR MMD and objective MMD.

Conclusions

Simple SR-1/4MILE and SR-BLOCKS are reasonable candidates to define MMD if the primary outcome of interest is incident MMD.

Wrist accelerometer shape feature derivation methods for assessing activities of daily living

Background

There has been an increasing interest in understanding the usefulness of wrist-based accelerometer data for physical activity (PA) assessment due to the ease of use and higher user compliance than other body placements. PA assessment studies have relied on machine learning methods which take accelerometer data in forms of variables, or feature vectors.

Methods

In this work, we introduce automated shape feature derivation methods to transform epochs of accelerometer data into feature vectors. As the first step, recurring patterns in the collected data are identified and placed in a codebook. Similarities between epochs of accelerometer data and codebook’s patterns are the basis of feature calculations. In this paper, we demonstrate supervised and unsupervised approaches to learn codebooks. We evaluated these methods and compared them with the standard statistical measures for PA assessment. The experiments were performed on 146 participants who wore an ActiGraph GT3X+ accelerometer on the right wrist and performed 33 activities of daily living.

Results

Our evaluations show that the shape feature derivation methods were able to perform comparably with the standard wrist model (F1-score: 0.89) for identifying sedentary PAs (F1-scores of 0.86 and 0.85 for supervised and unsupervised methods, respectively). This was also observed for identifying locomotion activities (F1-scores: 0.87, 0.83, and 0.81 for the standard wrist, supervised, unsupervised models, respectively). All the wrist models were able to estimate energy expenditure required for PAs with low error (rMSE: 0.90, 0.93, and 0.90 for the standard wrist, supervised, and unsupervised models, respectively).

Conclusion

The automated shape feature derivation methods offer insights into the performed activities by providing a summary of repeating patterns in the accelerometer data. Furthermore, they could be used as efficient alternatives (or additions) for manually engineered features, especially important for cases where the latter fail to provide sufficient information to machine learning methods for PA assessment.

Mitochondrial DNA variants and pulmonary function in older persons

BACKGROUND

We provide the first examination of mitochondrial DNA (mtDNA) variants and pulmonary function in older persons.

METHODS

Cross-sectional associations between mtDNA variants and pulmonary function were evaluated as a combined p-values meta-analysis, using data from two independent cohorts of older persons. The latter included white and black participants, aged ≥70 years, from the Lifestyle Interventions and Independence for Elders study (LIFE) (N = 1247) and the Health, Aging and Body Composition study (Health ABC) (N = 731), respectively. Pulmonary function included the forced expiratory volume in one-second as a Z-score (FEV1z) and the maximal inspiratory pressure (MIP) in cm of water.

RESULTS

In black participants, significant associations were found between mtDNA variants and MIP: m.7146A > G, COI (p = 3E-5); m.7389 T > C, COI (p = 2E-4); m.15301G > A, CYB (p = 9E-5); m.16265A > G, HV1 (p = 9E-5); meta-analytical p-values <0.0002. Importantly, these mtDNA variants were unique to black participants and were not present in white participants. Moreover, in black participants, aggregate genetic effects on MIP were observed across mutations in oxidative phosphorylation complex IV (p = 0.004), complex V (p = 0.0007), and hypervariable (p = 0.003) regions. The individual and aggregate variant results were significant after adjustment for multiple comparisons. Otherwise, no significant associations were detected for MIP in whites or for FEV1z in whites or blacks.

CONCLUSIONS

We have shown that mtDNA variants of African origin are cross-sectionally associated with MIP, a measure of respiratory muscle strength. Thus, our results establish the rationale for longitudinal studies to evaluate whether mtDNA variants of African origin identify those at risk of subsequently developing a respiratory muscle impairment (lower MIP values).

Effect of Hospitalizations on Physical Activity Patterns in Mobility-Limited Older Adults

OBJECTIVES

To evaluate the effect of hospitalizations on patterns of sedentary and physical activity time in mobility-limited older adults randomized to structured physical activity or health education.

DESIGN

Secondary analysis of investigator-blinded, parallel-group, randomized trial conducted at 8 U.S. centers between February 2010 and December 2013.

PARTICIPANTS

Sedentary men and women aged 70 to 89 at baseline who wore a hip-fitted accelerometer 7 consecutive days at baseline and 6, 12, and 24 months after randomization (N=1,341).

MEASUREMENTS

Participants were randomized to a physical activity (PA; n = 669) intervention that included aerobic, resistance, and flexibility training or to a health education (HE; n = 672) intervention that consisted of workshops on older adult health and light upper-extremity stretching. Accelerometer patterns were characterized as bouts of sedentary (<100 counts/min; ≥1, ≥10, ≥30, ≥60 minute lengths) and activity (≥100 counts/min; ≥1, ≥2, ≥5, ≥10 minute lengths) time. Each participant was categorized as having 0, 1 to 3, or 4 or more cumulative hospital days before each accelerometer assessment.

RESULTS

Hospitalization increased sedentary time similarly in both intervention groups (8 min/d for 1-3 cumulative hospital days and 16 min/d for ≥4 cumulative hospital days). Hospitalization was also associated with less physical activity time across all bouts of less than 10 minutes (≥1: -7 min/d for 1-3 cumulative hospital days, -16 min/d for ≥4 cumulative hospital days; ≥2: -5 min/d for 1-3 cumulative hospital days, -11 min/d for ≥4 cumulative hospital days; ≥5: -3 min/d for 1-3 cumulative hospital days, -4 min/d for ≥4 cumulative hospital days). There was no evidence of recovery to prehospitalization levels (time effect p >.41). PA participants had less sedentary time in bouts of less than 30 minutes than HE participants (-8 to -10 min/d) and more total activity (+3 to +6 min/d), although hospital-related changes were similar between the intervention groups (interaction effect p >.26).

CONCLUSION

Participating in a PA intervention before hospitalization had expected benefits, but participants remained susceptible to hospitalization's detrimental effects on their daily activity levels. There was no evidence of better activity recovery after hospitalization. J Am Geriatr Soc 67:261-268, 2019.