Metabolic Syndrome and Physical Performance: The Moderating Role of Cognition among Middle-to-Older-Aged Adults.

OBJECTIVE: Mobility limitation and cognitive decline are related. Metabolic syndrome (MetS), the clustering of three or more cardiovascular risk factors, is associated with decline in both mobility and cognition. However, the interrelationship among MetS, mobility, and cognition is unknown. This study investigated a proposed pathway where cognition moderates the relationship between MetS and Mobility. METHOD: Adults ages 45-90 years were recruited. MetS risk factors and mobility performance (Short Physical Performance Battery (SPPB) and gait speed) were evaluated. Cognition was assessed using a comprehensive neuropsychological battery. A factor analysis of neuropsychological test scores yielded three factors: executive function, explicit memory, and semantic/contextual memory. Multivariable linear regression models were used to examine the relationship among MetS, mobility, and cognition. RESULTS: Of the 74 participants (average age 61 ± 9 years; 41% female; 69% White), 27 (36%) participants manifested MetS. Mean SPPB score was 10.9 ± 1.2 out of 12 and gait speed was 1.0 ± 0.2 m/s. There were no statistically significant differences in mobility by MetS status. However, increase in any one of the MetS risk factors was associated with decreased mobility performance after adjusting for age and gender (SPPB score: ß (SE) -.17 (0.08), p < .05; gait speed: -.03 (.01), p < .01). Further adjusting for cognitive factors (SPPB score: explicit memory .31 (.14), p = .03; executive function 0.45 (0.13), p < .01; gait speed: explicit memory 0.04 (0.02), p = .03; executive function 0.06 (0.02), p < .01) moderated the relationships between number of metabolic risk factors and mobility. CONCLUSION: The relationship between metabolic risk factors and mobility may be moderated by cognitive performance, specifically through executive function and explicit memory.

Chronic Pain Characteristics and Gait in Older Adults: The MOBILIZE Boston Study II.

OBJECTIVE: To investigate a proposed cognitively-mediated pathway whereby pain contributes to gait impairments by acting as a distractor in community-living older adults. DESIGN: A cross-sectional study of a population-based cohort of older adults. SETTING: Urban and suburban communities in a large metropolitan area. PARTICIPANTS: Community-living participants (N=302) 70 years and older recruited from a previous population-based cohort. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Gait parameters including gait speed, stride length, double support and swing characteristics, and variability were assessed under single- and dual-task conditions involving cognitive challenges (eg, counting backward). A joint pain questionnaire assessed pain distribution in the back and major joints. We examined pain-gait relationships using multivariable linear regression and bootstrapping mediation procedures. RESULTS: Forty-three percent of participants had pain in 2 or more musculoskeletal sites. Pain distribution was related to slower gait speed and other gait characteristics for all gait conditions. Associations persisted after adjustment for age, sex, education, body mass index, medication, and vision. Decrements in gait measures related to pain were comparable with decrements in gait related to dual-task conditions. There were no differences in dual-task cost among the pain distribution groups. Adjusted for confounders, pain-gait relationships appear mediated by selective attention. CONCLUSIONS: These findings suggest that chronic pain contributes to decrements in gait, including slower gait speed, and that it operates through a cognitively-mediated pathway. Further research is needed to understand the mechanisms via pain alters mobility and to develop interventions to improve mobility among older adults with chronic pain.

Effects of Tai Chi on beta endorphin and inflammatory markers in older adults with chronic pain: an exploratory study.

The purpose of this exploratory study was to examine the effects of Tai Chi on blood levels of beta endorphin (ß-endorphin) and inflammatory markers in older adults with chronic pain. Forty community-dwelling older adults with chronic pain were randomized to Tai Chi or light physical exercise, and each offered twice weekly for 12 weeks. Following the 12-week intervention, neither Tai Chi nor light physical exercise changed levels of ß-endorphin and inflammatory markers. However, in older adults who completed 70% or more classes, Tai Chi significantly lowered levels of ß-endorphin (p < 0.05), whereas light physical exercise did not change levels of ß-endorphin. The results suggest that Tai Chi may reduce levels of ß-endorphin in older adults with chronic pain. Future studies are needed to better understand the role of the opioid analgesic system and immune system in regulating pain with aging and the long-term effects of Tai Chi on pain-related biomarkers.

Tai Chi for older adults with chronic multisite pain: a randomized controlled pilot study.

BACKGROUND: Chronic pain is associated with poorer cognition and mobility, and fall risk in older adults. AIMS: To investigate the feasibility of a randomized controlled trial of mind-body exercise (Tai Chi) versus light physical exercise in older adults with multisite pain. METHODS: Adults aged ≥ 65 years with multisite pain who reported falling in the past year or current use of an assistive device were recruited from Boston area communities. Participants were randomized to either a Tai Chi or a light physical exercise program, offered twice weekly for 12 weeks. The primary outcomes were feasibility and acceptability. Secondary outcomes included pain characteristics, cognition, physical function, gait mobility, fear of falling, and fall rate. RESULTS: Of 176 adults screened, 85 were eligible, and 54 consented and enrolled (average age 75 ± 8 years; 96.30% white; 75.93% female). The dropout rate was 18% for Tai Chi and 12% for light physical exercise. For those completing the study, exercise class attendance rate was 76% for Tai Chi and 82% for light physical exercise. There were no significant group differences in most secondary outcomes. Tai Chi significantly lowered pain severity (4.58 ± 1.73 to 3.73 ± 1.79, p < 0.01) and pain interference (4.20 ± 2.53 to 3.16 ± 2.28, p < 0.05), reduced fear of falling (90.82 ± 9.59 to 96.84 ± 10.67, p < 0.05), and improved several single-task and dual-task gait variables, while light physical exercise did not change these measures. DISCUSSION AND CONCLUSIONS: This study demonstrated the feasibility and acceptability of conducting a larger randomized controlled trial in older adults with multisite pain. Study findings and challenges encountered will inform future research.

Potential Benefits of Exergaming for Cognition and Dual-Task Function in Older Adults: A Systematic Review.

This paper provides a systematic review of current research findings using exergaming as a treatment for improving cognition and dual-task function in older adults. A literature search was conducted to collect exergaming intervention studies that were either randomized controlled or uncontrolled studies. Of the seven identified studies (five randomized controlled studies and two uncontrolled studies), three studies focused on cognitive function alone, two studies focused on dual-task function alone, and two studies measured both cognitive function and dual-task function. Current evidence supports that exergaming improves cognitive function and dual-task function, which potentially leads to fall prevention. However, it is unclear whether exergaming, which involves both cognitive input and physical exercise, has additional benefits compared with traditional physical exercise alone. Further studies should include traditional exercise as a control group to identify these potential, additional benefits.

Changes in Mild Neurocognitive Disorder Status in Mobility Limited Older Primary Care Patients: Implications for Rehabilitative Care.

OBJECTIVE: The aim of the study is to identify potential rehabilitative treatment targets associated with participants' annual cognitive status. DESIGN: A cohort study patients with self-reported mobility limitation who completed neuropsychological, physical performance testing, and questionnaires at baseline to 2-year follow-up were categorized into three groups (persistently cognitively normal, nonpersistent mild neurocognitive disorder, and persistently mild neurocognitive disorder) based on their annual cognitive status using baseline, years 1 and 2 performance on Hopkins Verbal Learning, Trail Making, and Digit Symbol Substitution Tests. Repeated measures multinomial regression analysis was used to examine the differences between groups and associated characteristics. RESULTS: Study included 349 participants (mean age, 76 ± 7) with 57% of participants were persistently cognitively normal, 16% persistently mild neurocognitive disorder, and 27% nonpersistent mild neurocognitive disorder over 2 yrs of follow-up. Faster gait speed (relative risk reduction, 0.64-0.89) was associated with risk reduction and increase in depressive symptoms (relative risk reduction, 1.09-1.12) was associated with greater risk of being classified into the nonpersistent or persistently mild neurocognitive disorder compared with persistently cognitively normal. CONCLUSIONS: Variability across cognitive status over time was observed. Gait speed and depressive symptoms were modifiable risk factors associated with nonpersistent and persistent mild neurocognitive disorder status. This study reinforces the potential benefit of multifaceted rehabilitation for preventing and treating older adults with mobility and/or cognitive problems.

Reliability of Virtual Physical Performance Assessments in Veterans During the COVID-19 Pandemic.

OBJECTIVE: To determine the reliability of 3 physical performance tests performed via a telehealth visit (30-s arm curls test, 30-s chair stand test, 2-min step test) among community-dwelling older veterans. DESIGN: Cross sectional study. SETTING: Virtual. PARTICIPANTS: Veterans (N=55; mean age 75y) who enrolled in Gerofit, a virtual group exercise program. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were tested by 2 different assessors at 1 time point. The intraclass correlation coefficient (ICC) with 95% confidence intervals and Bland-Altman plots were used as measures of reliability. To assess generalizability, ICCs were further evaluated by health conditions (type 2 diabetes, arthritis, obesity, depression). RESULTS: Assessments were conducted among 55 participants. The ICC was above 0.98 for all 3 tests across health conditions and Bland-Altman plots indicated that there were no significant systematic errors in the measurement. CONCLUSIONS: The virtual physical performance measures appear to have high reliability and the findings are generalizable across health conditions among veterans. Thus, they are reliable for evaluating physical performance in older veterans in virtual settings.

Evaluating the Feasibility and Effects of a Short-Term Task Specific Power Training With and Without Cognitive Training Among Older Adults With Slow Gait Speed: A Pilot Study.

OBJECTIVE: To investigate the feasibility and efficacy of short-term functional power training and further examine whether the addition of cognitive training targeting sustained attention and inhibitory control would augment the effect on the outcomes. DESIGN: Randomized pilot study. SETTING: Clinical research facility. PARTICIPANTS: Community-dwelling primary care patients (N=25) aged >65 years with mobility limitation within the VA Boston Healthcare System. INTERVENTIONS: Participants were randomly assigned to either functional power training (n=14) or functional power+cognitive training (n=11), offered 3 times a week for 6 weeks. Session durations were either 70 minutes (functional power+cognitive training) or 40 minutes (functional power training). MAIN OUTCOME MEASURES: We evaluated feasibility (dropouts, attendance), mobility performance (Short Physical Performance Battery [SPPB]), leg power [stair climb test]), dynamic balance [figure-of-8], and gait characteristics [gait speed, stance time, step width, swing time, step length, variabilities under single-task and dual-task conditions]). Nonparametric analyses were used to compare overall pre-post changes and between-group differences. RESULTS: Of the 39 veterans screened, 25 were randomized and enrolled. Twenty-one men with a mean age 76±7 years completed the study; 86% were white. Participants had a mean SPPB score of 8.3±1.6 out of 12. For those completing the study, overall attendance was 79%. Among all participants, clinically relevant and/or statistically significant median change in mobility performance (∆1 point), leg power (∆25.0W), dynamic balance (∆-1.1s), and gait characteristics (gait speed [∆0.08s, ∆0.09s], step length [∆1.9cm, ∆3.8cm], and stance time [∆-0.02s, ∆-0.05s] under single- and dual-task, respectively) were observed after 6 weeks of training. There were no statistically significant group differences in dropouts, attendance rate, or any of the outcomes based on cognitive training status. CONCLUSIONS: Short-term functional power training with or without a cognitive training led to clinically meaningful improvements in mobility performance, leg power, dynamic balance, and gait characteristics. These findings add to the body of evidence supporting the benefits of functional power training on clinically relevant outcomes. Additional cognitive training did not have an added effect on the study outcomes from our study. Further research is needed.

Effects of meditation and mind-body exercise on brain-derived neurotrophic factor: A literature review of human experimental studies.

This paper provides a literature review of current studies investigating the effects of meditation and mind-body exercise on peripheral concentrations of brain-derived neurotrophic factor (BDNF), an important mediator of the neuroplasticity of the central nervous system and cognitive function. A literature search was conducted to collect currently published randomized controlled, non-randomized controlled and uncontrolled intervention studies. Fifteen studies were identified; and among these studies, seven were randomized controlled studies, three were non-randomized studies, and five were uncontrolled studies. Current limited evidence tends to support that mindfulness meditation and mind-body exercise (e.g. yoga and tai chi) increase circulating BDNF concentrations in healthy and diseased individuals. It is noteworthy that these findings are based on current studies with a relatively small sample size, or without a randomized controlled design. Further studies are needed to identify a definite effect of meditation or mind-body exercise on BDNF and its role in improving/maintaining brain functions in various populations.

Effects of Exergaming on Cognition and Gait in Older Adults at Risk for Falling.

PURPOSE: To test whether an 8-wk exergaming (EG) program would improve cognition and gait characteristics compared with a traditional physical exercise (TPE) program in older adults at risk for falling. METHODS: A pilot quasi-experimental study was conducted in adults age ≥65 yr at risk for falls, living in senior communities. Participants enrolled (n = 35) in either exercise program offered twice weekly for 8 wk. Cognition and single-task and dual-task gait characteristics were measured before and after the 8-wk exercise intervention. For each outcome, a repeated-measures ANCOVA adjusted for age, gender, and exercise intensity (ratings of perceived exertion, RPE) was used to examine the group-time interaction. RESULTS: Twenty-nine participants (age, 77 ± 7 yr) completed either the EG program (n = 15) or the TPE program (n = 14). Statistically significant group-time interactions were observed in Trail Making Test Part A (P < 0.05) and single-task gait speed, stride length, swing time percentage, and double support percentage (all P < 0.05), and marginal group differences were observed in Mini-Mental State Examination (P = 0.07), all favoring the EG program. There were no statistically significant group differences in dual-task gait measurements except for swing time percentage and double support percentage, favoring the EG program. CONCLUSIONS: An 8-wk EG program for older adults at risk for falls contributed to modest improvements in a number of cognitive measures and single-task but limited improvements in dual-task gait measures, compared with TPE. These findings support the need for larger trials to determine cognitive and mobility benefits related to EG.

Physical Activity Domains/Recommendations and Leukocyte Telomere Length in U.S. Adults.

PURPOSE: The purpose of this study was to examine the associations between different physical activity (PA) domains, PA recommendations, and leukocyte telomere length (LTL) using data from a nationally representative sample of U.S. adults in the National Health and Nutrition Examination Survey, 1999-2002. METHODS: A total of 6933 U.S. adults (3402 men, 3531 women; age range: 20-84 yr) who completed demographic, general health and PA questionnaires and provided a blood sample were included in the analyses. Multivariable-adjusted linear regression models were used to determine associations between PA (domain-specific PA [household/yard work PA, transportation PA, moderate leisure time PA (LTPA), and vigorous LTPA], total moderate PA and PA recommendation groups), and log-transformed LTL adjusting for age, gender, education, cigarette smoking, alcohol consumption, and body mass index. RESULTS: On average, an increase of 1 h·wk of vigorous LTPA was associated with a 0.31% (P < 0.001) longer LTL, and an increase of 1 h·wk of household/yard work PA was associated with a 0.21% (P = 0.03) shorter LTL while adjusted for sociodemographic and health behavior covariates. Neither transportation PA nor moderate LTPA was significantly associated with LTL. In addition, compared with not meeting the PA recommendation (<150 min·wk), exceeding the recommended PA levels (≥300 min·wk) was positively associated with longer LTL (P = 0.04), whereas there was no difference in telomere length between those not meeting versus those meeting the PA recommendation (150-299 min·wk). CONCLUSION: Greater engagement in vigorous LTPA and exceeding the PA recommendation may have a protective effect against telomere shortening. Future studies should examine the association between PA and LTL by exploring potential mediators such as sedentary behavior, genetics, nutrition, and chronic diseases.

Physical activity and telomere length: Impact of aging and potential mechanisms of action.

Telomeres protect the integrity of information-carrying DNA by serving as caps on the terminal portions of chromosomes. Telomere length decreases with aging, and this contributes to cell senescence. Recent evidence supports that telomere length of leukocytes and skeletal muscle cells may be positively associated with healthy living and inversely correlated with the risk of several age-related diseases, including cancer, cardiovascular disease, obesity, diabetes, chronic pain, and stress. In observational studies, higher levels of physical activity or exercise are related to longer telomere lengths in various populations, and athletes tend to have longer telomere lengths than non-athletes. This relationship is particularly evident in older individuals, suggesting a role of physical activity in combating the typical age-induced decrements in telomere length. To date, a small number of exercise interventions have been executed to examine the potential influence of chronic exercise on telomere length, but these studies have not fully established such relationship. Several potential mechanisms through which physical activity or exercise could affect telomere length are discussed, including changes in telomerase activity, oxidative stress, inflammation, and decreased skeletal muscle satellite cell content. Future research is needed to mechanistically examine the effects of various modalities of exercise on telomere length in middle-aged and older adults, as well as in specific clinical populations.