Weakness Thresholds Are Differentially Linked to Cognitive Function by Obesity Status in Older Americans.

Background: Weakness can be operationalized with several thresholds, which in turn, could impact associations with cognitive impairment when considering obesity status. Objective: We examined the associations of absolute, normalized, and collective weakness thresholds on future cognitive impairment by obesity status in older adults. Methods: We performed a secondary data analysis on the 2006-2018 waves of the Health and Retirement Study. A spring-type dynamometer collected handgrip strength (HGS). Males were categorized weak if their HGS was <35.5-kg (absolute), <0.45-kg/kg (body mass normalized), or <1.05-kg/kg/m2 (body mass index (BMI) normalized), while females were defined as weak if their HGS was <20.0-kg, <0.337-kg/kg, or <0.79-kg/kg/m2. The modified Telephone Interview of Cognitive Status examined cognitive function. Persons scoring ≤10 had a cognitive impairment. Obesity was categorized as BMI ≥30 kg/m2. Results: We included 7,532 and 3,584 persons aged ≥65-years living without and with obesity, respectively. Those without obesity but beneath the absolute weakness threshold had 1.54 (95% confidence interval (CI): 1.24-1.91) greater odds for future cognitive impairment. Persons with obesity and beneath each threshold also had greater odds for future cognitive impairment: 1.89 (95% CI: 1.28-2.78) for absolute, 2.17 (95% CI: 1.02-4.62) for body mass normalized, and 1.75 (95% CI: 1.10-2.80) for BMI normalized. Older Americans without obesity but underneath all the weakness thresholds had 1.32 (95% CI: 1.00-1.74) greater odds for impairment in cognitive function, while persons with obesity had 2.76 (95% CI: 1.29-5.93) greater odds. Conclusions: There should be consideration for how body size and different weakness thresholds may influence future cognitive outcomes.

Collective Weakness Is Associated With Time to Mortality in Americans.

ABSTRACT: McGrath, R, McGrath, BM, Jurivich, D, Knutson, P, Mastrud, M, Singh, B, and Tomkinson, GR. Collective weakness is associated with time to mortality in Americans. J Strength Cond Res XX(X): 000-000, 2024-Using new weakness cutpoints individually may help estimate time to mortality, but their collective use could improve value. We sought to determine the associations of (a) each absolute and body size normalized cut point and (b) collective weakness on time to mortality in Americans. The analytic sample included 14,178 subjects aged ≥50 years from the 2006-2018 waves of the Health and Retirement Study. Date of death was confirmed from the National Death Index. Handgrip dynamometry measured handgrip strength (HGS). Men were categorized as weak if their HGS was <35.5 kg (absolute), <0.45 kg·kg-1 (body mass normalized), or <1.05 kg·kg-1·m-2 (body mass index [BMI] normalized). Women were classified as weak if their HGS was <20.0 kg, <0.337 kg·kg-1, or <0.79 kg·kg-1·m-2. Collective weakness categorized persons as below 1, 2, or all 3 cutpoints. Cox proportional hazard regression models were used for analyses. Subject values below each absolute and normalized cutpoint for the 3 weakness parameters had a higher hazard ratio for early all-cause mortality: 1.45 (95% confidence interval [CI]: 1.36-1.55) for absolute weakness, 1.39 (CI: 1.30-1.49) for BMI normalized weakness, and 1.33 (CI: 1.24-1.43) for body mass normalized weakness. Those below 1, 2, or all 3 weakness cut points had a 1.37 (CI: 1.26-1.50), 1.47 (CI: 1.35-1.61), and 1.69 (CI: 1.55-1.84) higher hazard for mortality, respectively. Weakness determined by a composite measure of absolute and body size adjusted strength capacity provides robust prediction of time to mortality, thus potentially informing sports medicine and health practitioner discussions about the importance of muscle strength during aging.

Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies.

OBJECTIVE: To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults. DESIGN: Overview of systematic reviews. DATA SOURCE: Five bibliographic databases were searched from January 2002 to March 2024. RESULTS: From the 9062 papers identified, we included 26 systematic reviews. We found eight meta-analyses that described five unique mortality outcomes among general populations. CRF had the largest risk reduction for all-cause mortality when comparing high versus low CRF (HR=0.47; 95% CI 0.39 to 0.56). A dose-response relationship for every 1-metabolic equivalent of task (MET) higher level of CRF was associated with a 11%-17% reduction in all-cause mortality (HR=0.89; 95% CI 0.86 to 0.92, and HR=0.83; 95% CI 0.78 to 0.88). For incident outcomes, nine meta-analyses described 12 unique outcomes. CRF was associated with the largest risk reduction in incident heart failure when comparing high versus low CRF (HR=0.31; 95% CI 0.19 to 0.49). A dose-response relationship for every 1-MET higher level of CRF was associated with a 18% reduction in heart failure (HR=0.82; 95% CI 0.79 to 0.84). Among those living with chronic conditions, nine meta-analyses described four unique outcomes in nine patient groups. CRF was associated with the largest risk reduction for cardiovascular mortality among those living with cardiovascular disease when comparing high versus low CRF (HR=0.27; 95% CI 0.16 to 0.48). The certainty of the evidence across all studies ranged from very low-to-moderate according to Grading of Recommendations, Assessment, Development and Evaluations. CONCLUSION: We found consistent evidence that high CRF is strongly associated with lower risk for a variety of mortality and incident chronic conditions in general and clinical populations.

Dropout From Exercise Interventions in Adults With Knee or Hip Osteoarthritis: A Systematic Review and Meta-analysis.

OBJECTIVE: To investigate the prevalence and moderators of dropout rates among adults with knee or hip osteoarthritis participating in exercise randomized controlled trials (RCTs). DATA SOURCES: Two authors searched Embase, CINAHL, PsycARTICLES, and PubMed up to 01/09/2023. STUDY SELECTION: We included RCTs of exercise interventions in people with knee or hip osteoarthritis that reported dropout rates. DATA EXTRACTION: Dropout rates from exercise and control conditions and exerciser/participant, provider, and design/implementation related moderators. DATA SYNTHESIS: In total, 209 RCTs involving 277 exercise arms in 13,102 participants were included (mean age at study level=64 years; median prevalence of men participants=26.8%). The trim-and-fill-adjusted prevalence of dropout across all RCTs was 17.5% (95% CI=16.7%-18.2%), which is comparable with dropout observed in control conditions (trim-and-fill-adjusted odds ratio=0.89; 95% CI=0.71-1.12, P=.37). Higher prevalence of antidepressant use at study-level predicted higher dropout (R2=0.75, P=.002, N RCTs=6, n exercisers=412). Supervision by an exercise professional was associated with lower dropout rates, with a trim-and-fill-adjusted rate of 13.2% (95% CI=11.7%-14.9%) compared with 20.8% without supervision (95% CI=18.3%-23.5%) (P<.001). CONCLUSIONS: Dropout rates for exercise in RCTs are comparable with control conditions, suggesting that exercise is a generally well-accepted intervention. However, interventions should be supervised by an exercise professional, such as a physiotherapist or exercise physiologist, to further minimize the risk of dropout. Health professionals should consider participants' use of antidepressants as a risk factor for dropout from exercise.

Physiotherapists often encounter clients disclosing suicidal thoughts and behaviors: a cross-sectional survey of Australian physiotherapists.

BACKGROUND: All health professionals have a role in suicide prevention, although little is known about physiotherapists' contact with clients experiencing suicidal thoughts and behaviors. OBJECTIVE: The aims of this study were to investigate physiotherapists' self-reported frequency of contact with clients who disclose suicidal thoughts and behaviors and to identify potential factors associated with frequency of contact. METHODS: Three-hundred and thirty-eight Australian physiotherapists were surveyed using an online questionnaire, with an estimated response rate of 6.1%. Data were analyzed using descriptive analysis and logistic regression. RESULTS: Over half the respondents (52.1%) reported encountering clients at least once a year who disclosed suicidal thoughts, and nearly half (49.4%) reported having received at least one disclosure of a suicide plan at some point in their career. Among those working in the public sector, 67.5% of respondents reported having received a disclosure of a suicide plan, and almost all physiotherapists working in pain management reported having received such a disclosure (93.8%). The binary logistic regression model explained approximately 39.7% of the variance in whether a physiotherapist had a client disclose a plan for suicide at some point in their career or not. CONCLUSION: The results highlight that all physiotherapists should receive training in suicide prevention.

Increased frequency of light physical activity during midlife and old age buffers against cognitive declines.

Although it is well established that moderate-to-vigorous physical activity (MVPA) buffers against declines in cognitive health, less is known about the benefits of light physical activity (LPA). Research on the role of LPA is crucial to advancing behavioral interventions to improve late life health outcomes, including cognitive functioning, because this form of physical activity remains more feasible and amenable to change in old age. Our study examined the extent to which increases in LPA frequency protected against longitudinal declines in cognitive functioning and whether such a relationship becomes pronounced in old age when opportunities for MVPA are typically reduced. We analyzed 9-year data from the national Midlife in the United States Study (n = 2,229; Mage = 56 years, range = 33-83; 56% female) using autoregressive models that assessed whether change in LPA frequency predicted corresponding changes in episodic memory and executive functioning in middle and later adulthood. Increases in LPA frequency predicted less decline in episodic memory (ß = 0.06, p = .004) and executive functioning (ß = 0.14, p < .001) over the 9-year follow-up period, even when controlling for moderate and vigorous physical activity. Effect sizes for moderate and vigorous physical activity were less than half that observed for LPA. Moderation models showed that, for episodic memory, the benefits of increases in LPA frequency were more pronounced at older ages. Findings suggest that increases in LPA over extended periods of time may help slow age-related cognitive declines, particularly in later life when opportunities for MVPA are often diminished.

Dropout From Exercise Interventions in Adults With Fibromyalgia: A Systematic Review and Meta-analysis.

OBJECTIVE: To meta-analyze the prevalence and predictors of dropout rates among adults with fibromyalgia participating in exercise randomized controlled trials (RCTs). DATA SOURCES: Two authors searched Embase, CINAHL, PsycARTICLES, and Medline up to 01/21/2023. STUDY SELECTION: We included RCTs of exercise interventions in people with fibromyalgia that reported dropout rates. DATA EXTRACTION: Dropout rates from exercise and control conditions and exerciser/participant, provider, and design/implementation related predictors. DATA SYNTHESIS: A random effects meta-analysis and meta-regression were conducted. In total, 89 RCTs involving 122 exercise arms in 3.702 people with fibromyalgia were included. The trim-and-fill-adjusted prevalence of dropout across all RCTs was 19.2% (95% CI=16.9%-21.8%), which is comparable with the dropout observed in control conditions with the trim-and-fill-adjusted odds ratio being 0.31 (95% CI=0.92-1.86, P=.44). Body mass index (R2=0.16, P=.03) and higher effect of illness (R2=0.20, P=.02) predicted higher dropout. The lowest dropout was observed in exergaming, compared with other exercise types (P=.014), and in lower-intensity exercises, compared with high intensity exercise (P=.03). No differences in dropout were observed for the frequency or duration of the exercise intervention. Continuous supervision by an exercise expert (eg, physiotherapist) resulted in the lowest dropout rates (P<.001). CONCLUSIONS: Exercise dropout in RCTs is comparable with control conditions, suggesting that exercise is a feasible and accepted treatment modality; however, interventions are ideally supervised by an expert (eg, physiotherapist) to minimize the risk of dropout. Experts should consider a high BMI and the effect of the illness as risk factors for dropout.

Muscle specific declines in oxygen saturation during acute ambulation with hands-free and conventional mobility devices.

Disuse is associated with reduced muscle oxygen saturation (SmO2). Improving oxygen delivery to tissues is important for healing, preventing muscle atrophy, and reducing the risk of deep vein thrombosis. Mobility devices are used during disuse periods to ambulate and protect the injured limb. This study examined SmO2 in walking and ambulation with various mobility devices. Thirty-eight participants randomly completed four, ten-minute trials which included: (1) walking, (2) medical kneeling scooter (MKS), (3) hands-free crutch (HFC), and (4) axillary crutch (AC). During each trial, near infrared spectroscopy sensors were placed on the vastus lateralis (VL), biceps femoris (BF), and lateral gastrocnemius (LG) of the right limb. Compared to walking, all mobility devices showed a decline in SmO2 in the VL of ∼10% (mean ± SD; 75% ± 12%-65% ± 17%, P < 0.05). In the BF, SmO2 declined ∼9% in AC compared to walking (76% ± 12%-67% ± 17%, P = 0.025). In the LG, SmO2 declined in AC (64% ± 16%) compared to MKS (70% ± 15%, P = 0.005). There were no differences in LG SmO2 compared to walking (69% ± 13%) in MKS (P > 0.05) or HFC (65% ± 15%, P > 0.05). In young, healthy volunteers, the use of mobility devices altered muscle oxygenation in several muscles. AC reduced muscle oxygenation in the VL, BF, and LG; while MKS and HFC maintained BF and LG muscle oxygenation at a level consistent with ambulatory walking.

Recommended approaches to assessing and managing physiotherapy clients experiencing psychological distress: a systematic mapping review.

BACKGROUND: Some physiotherapists find assessing and managing clients experiencing psychological distress challenging and are uncertain regarding the boundaries of the profession's scope. OBJECTIVE: To map the approaches recommended for physiotherapists in scholarly literature, with respect to the assessment and management of clients experiencing psychological distress. METHODS: A systematic mapping review was conducted. CINAHL, APA PsycINFO, Embase, and Medline ALL databases were systematically searched for secondary and tertiary literature relevant to the research objective. Recommended approaches were extracted from each article and analyzed descriptively and thematically. RESULTS: 3884 records were identified with 40 articles meeting the inclusion/exclusion criteria. Most recommendations related to identifying, assessing, and managing pain-related distress, with depression screening and referral also receiving some attention. Three approaches to detecting and assessing psychological distress were identified: 1) brief depression screen; 2) integrated suicide/nonsuicidal self-harm and depression screen; and 3) multidimensional screen and health-related distress assessment. Regarding the management of psychological distress the main approaches identified were: 1) education and reassurance; 2) cognitive-behavioral approaches; 3) mindfulness; and 4) case management. CONCLUSION: While assessment and management of health-related distress by physiotherapists is commonly recommended, further guidance is needed to differentiate various forms of distress.

Prevalence and Trends of Basic Activities of Daily Living Limitations in Middle-Aged and Older Adults in the United States.

BACKGROUND: Population-level surveillance of the prevalence and trends of basic self-care limitations will help to identify the magnitude of physical disablement in the rapidly growing older American demographic. We sought to evaluate the prevalence and trends of activities of daily living (ADL) limitations in the United States. METHODS: The analytic sample included 30,418 Americans aged ≥50 years from the 2006-2018 waves of the Health and Retirement Study. ADLs were self-reported. Weighted prevalence estimates were presented, and trends analyses were performed. RESULTS: Although overall ADL disability prevalence was 16.5% (95% confidence interval: 15.8-17.2) in 2018, there were no changes in limitations during the study period (p = 0.52). Older adults had a greater ADL disability prevalence than middle-aged adults (p < 0.001). While older persons experienced a declining trend of ADL limitations (p < 0.001), middle-aged persons had an increasing trend (p < 0.001). Males had a lower ADL limitation prevalence than females (p < 0.001). Hispanic and non-Hispanic Black had a higher ADL disability prevalence than non-Hispanic White (p < 0.001). CONCLUSIONS: This investigation revealed that while the estimated prevalence of ADL limitations in the United States was substantial, changes in such limitations were not observed. Our findings can help guide ADL screening, target sub-populations with an elevated ADL limitation prevalence, and inform interventions.

Prevalence and Trends of Slow Gait Speed in the United States.

Gait speed is a simple, effective indicator of age-related disease and disability. We sought to examine the prevalence and trends of slow gait speed in older Americans. Our unweighted analytic sample included 12,427 adults aged ≥ 65 years from the 2006-2016 waves of the Health and Retirement Study. Gait speed was measured in participant residences. Persons with gait speed < 0.8 or <0.6 m/s were slow. Sample weights were used to generate nationally representative estimates. The overall estimated prevalence of slow gait speed with the <0.8 m/s cut-point was 48.6% (95% confidence interval (CI): 47.4-49.8) in the 2006-2008 waves yet was 45.7% (CI: 44.3-47.1) in the 2014-2016 waves, but this downward trend was not statistically significant (p = 0.06). The estimated prevalence of slowness with the <0.6 m/s cut-point was 21.3% (CI: 20.4-22.3) for the 2006-2008 waves, 18.5% (CI: 17.5-19.4) for the 2010-2012 waves, and 19.2% (CI: 18.2-20.2) for the 2014-2016 waves, but there were again no significant trends (p = 0.61). Our findings showed that the estimated prevalence of slow gait speed in older Americans is pronounced, and different cut-points largely inform how slowness is categorized. Continued surveillance of slowness over time will help guide screening for disablement and identify sub-populations at greatest risk for targeted interventions.

Examining the role of different weakness categories for mobility and future falls in older Americans.

BACKGROUND: Recently developed absolute and body size normalized handgrip strength (HGS) cut-points could be used individually and collectively to predict mobility problems and falls. AIMS: We examined the associations of (1) each absolute and normalized weakness cut-point, (2) collective weakness categories, and (3) changes in weakness status on future falls in older Americans. METHODS: The analytic sample included 11,675 participants from the 2006-2018 waves of the Health and Retirement Study. Falls were self-reported. Men were classified as weak if their HGS was < 35.5-kg (absolute), < 0.45 kg/kg (body mass normalized), or < 1.05 kg/kg/m2 (body mass index normalized). While, women were considered weak if their HGS was < 20.0-kg, < 0.337 kg/kg, or < 0.79 kg/kg/m2. Collective weakness categorized those below 1, 2, or all 3 cut-points. The collective weakness categories were also used to observe changes in weakness status over time. RESULTS: Older Americans below each absolute and normalized cut-point had greater odds for future falls: 1.23 (95% confidence interval (CI): 1.15-1.32) for absolute weakness, 1.20 (CI 1.11-1.29) for body mass index normalized weakness, and 1.26 (CI 1.17-1.34) for body mass normalized weakness. Persons below 1, 2, or all 3 weakness cut-points had 1.17 (CI 1.07-1.27), 1.29 (CI 1.18-1.40), and 1.36 (CI 1.24-1.48) greater odds for future falls, respectively. Those in some changing weakness categories had greater odds for future falls: 1.26 (CI 1.08-1.48) for persistent and 1.31 (CI 1.11-1.55) for progressive. DISCUSSION: Collectively using these weakness cut-points may improve their predictive value. CONCLUSION: We recommend HGS be evaluated in mobility and fall risk assessments.

Preventing Suicide: Time to Mobilize the Physical Therapist Workforce.

Each year, approximately 700,000 people, including 46,000 Americans, die by suicide; however, many more people experience suicidal thoughts and behaviors. Historically, the prevention of suicide has largely been the domain of mental health professionals working within specialist mental health care settings. An issue with this approach is that many individuals who experience suicidal ideation never disclose these thoughts to a mental health professional. The nonprofessional and paraprofessional mental health movement aims to bring suicide prevention to the people who need it, rather than wait for them to seek help. The nonprofessional and paraprofessional mental health movement does so by upskilling people who are not recognized as mental health professionals but may have contact with people experiencing suicidal thoughts and behaviors. In this Perspective, we argue that physical therapists are well-positioned to engage in suicide prevention. For example, physical therapists working in pain management are likely to frequently encounter clients experiencing suicidal thoughts and behaviors. Physical therapy is also viewed as a physical health profession, meaning that they may have contact with a broad range of populations at high risk of suicide who may be difficult to reach through traditional channels (eg, men from rural communities). Physical therapists will require training on how to provide crisis support, including how to link clients with appropriate mental health services. However, given the size of the physical therapist workforce globally, the impact of mobilizing the physical therapist workforce could be significant.

Using Electronic Handgrip Dynamometry and Accelerometry to Examine Multiple Aspects of Handgrip Function in Master Endurance Athletes: A Pilot Study.

ABSTRACT: Klawitter, LA, Hackney, KJ, Christensen, BK, Hamm, JM, Hanson, M, and McGrath, R. Using electronic handgrip dynamometry and accelerometry to examine multiple aspects of handgrip function in master endurance athletes: A Pilot Study. J Strength Cond Res 37(9): 1777-1782, 2023-Electronic handgrip dynamometry and accelerometry may provide novel opportunities to comprehensively measure muscle function for human performance, especially for master athletes. This investigation sought to determine the multivariate relationships between maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness to derive one or more handgrip principal components in master-aged endurance athletes. We included n = 31 cyclists and triathletes aged 35-70 years. Maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness were measured twice on each hand using electronic handgrip dynamometry and accelerometry. The highest performing measures were included in the analyses. A principal component analysis was conducted to derive a new collection of uncorrelated variables from the collected handgrip measurements. Principal components with eigenvalues >1.0 were kept, and individual measures with a factor loading of |>0.40| were retained in each principal component. There were 3 principal components retained with eigenvalues of 2.46, 1.31, and 1.17. The first principal component, "robust strength," contained maximal strength, rate of force development, submaximal force control, and neuromuscular steadiness. The second principal component, "bilateral synergy," contained asymmetry and bimanual coordination, whereas the third principal component, "muscle conditioning," contained fatigability. Principal components 1, 2, and 3 explained 44.0, 31.6, and 24.4% of the variance, respectively. Different dimensions of muscle function emerged from our findings, suggesting the potential of a muscle function battery. Further research examining how these measures are associated with appropriate human performance metrics and lower extremity correlates is warranted.

Tracking handgrip strength asymmetry from childhood to mid-life.

AIM: Determine if asymmetric handgrip strength exists in childhood and adulthood and quantify the degree of tracking of handgrip strength asymmetry over time. METHODS: Participants from the Childhood Determinants of Adult Health Study had their right and left handgrip strength measured using handgrip dynamometry in childhood (1985: 9-15 y), young adulthood (2004-06: 26-36 y) and/or mid-adulthood (2014-19: 36-49 y). Handgrip strength asymmetry was calculated as: strongest handgrip strength/strongest handgrip strength on the other hand. Participants were categorised based on the degree of their asymmetry (0.0%-10.0%, 10.1%-20.0%, 20.1%-30.0%, >30.0%). Tracking was quantified using Spearman's correlations and log binomial regression. RESULTS: Handgrip strength asymmetry was present in childhood and adulthood (>30.0% asymmetry: childhood = 6%, young adulthood = 3%, mid-adulthood = 4%). Handgrip strength asymmetry did not track between childhood and young- (r = 0.06, 95% CI = -0.02, 0.12) and mid-adulthood (r = 0.01, 95% CI = -0.09, 0.10). Tracking was more apparent between young- and mid-adulthood (r = 0.16, 95% CI = 0.09, 0.22). Participants with >30.0% asymmetry were at greater risk to maintain this status between childhood and young- (RR = 3.53, 95% CI = 1.15, 10.87) and mid-adulthood (RR = 2.14, 95% CI = 0.45, 10.20). CONCLUSION: Although handgrip strength asymmetry tracked relatively poorly, asymmetric handgrip strength was apparent in children and adults. Handgrip strength asymmetry does not exclusively affect older adults and should be considered in protocols to better understand its role across the life course.

Prevalence and Trends of Weakness Among Middle-Aged and Older Adults in the United States.

ABSTRACT: McGrath, R, FitzSimmons, S, Andrew, S, Black, K, Bradley, A, Christensen, BK, Collins, K, Klawitter, L, Kieser, J, Langford, M, Orr, M, and Hackney, KJ. Prevalence and trends of weakness among middle-aged and older adults in the United States. J Strength Cond Res 37(12): 2484-2490, 2023-Muscle weakness, which is often determined with low handgrip strength (HGS), is associated with several adverse health conditions; however, the prevalence and trends of weakness in the United States is not well-understood. We sought to estimate the prevalence and trends of weakness in Americans aged at least 50 years. The total unweighted analytic sample included 22,895 Americans from the 2006-2016 waves of the Health and Retirement Study. Handgrip strength was measured with a handgrip dynamometer. Men with weakness were below at least one of the absolute or normalized (body mass, body mass index) cut points: <35.5 kg, <0.45 kg/kg, <1.05 kg/kg/m 2 . The presence of any weakness in women was also identified as being below one of the absolute or normalized HGS cut points: <20.0 kg, <0.34 kg/kg, or <0.79 kg/kg/m 2 . There was an increasing trend in the prevalence of any weakness over time ( p < 0.001). The prevalence of weakness was 45.1% (95% confidence interval [CI]: 44.0-46.0) in the 2006-2008 waves and 52.6% (CI: 51.5-53.7) in the 2014-2016 waves. Weakness prevalence was higher for older (≥65 years) Americans (64.2%; CI: 62.8-65.5) compared with middle-aged (50-64 years) Americans (42.2%; CI: 40.6-43.8) in the 2014-2016 waves. Moreover, the prevalence of weakness in the 2014-2016 waves was generally higher in women (54.5%; CI: 53.1-55.9) than in men (50.4%; CI: 48.7-52.0). Differences existed in weakness prevalence across races and ethnicities. The findings from our investigation suggest that the prevalence of weakness is overall pronounced and increasing in Americans. Efforts for mitigating and better operationalizing weakness will elevate in importance as our older American population grows.

The Role of Different Weakness Cut-Points for Future Cognitive Impairment in Older Americans.

OBJECTIVES: New absolute and normalized handgrip strength (HGS) cut-points may not yield similar predictive value for cognitive performance. We sought to determine the associations of (1) each absolute and normalized weakness cut-point, and (2) compounding weakness on future cognitive impairment in older Americans. DESIGN: Longitudinal panel. SETTING AND PARTICIPANTS: The analytic sample included 11,116 participants aged ≥65 years from the 2006 to 2018 waves of the Health and Retirement Study. Participants from the Health and Retirement Study completed detailed interviews that included physical measures and core interviews. METHODS: The modified Telephone Interview of Cognitive Status assessed cognitive function and persons scoring <11 were classified as having a cognitive impairment. A handgrip dynamometer measured HGS. Men were considered weak if their HGS was <35.5 kg (absolute), <0.45 kg/kg (body mass normalized), or <1.05 kg (body mass index normalized), whereas women were classified as weak if their HGS was <20.0 kg, <0.337 kg/kg, or <0.79 kg. Compounding weakness included those below 1, 2, or all 3 cut-points. Generalized estimating equations quantified the associations. RESULTS: Persons considered weak under the absolute cut-point had 1.62 (95% CI 1.34-1.96) greater odds for future cognitive impairment, but no significant associations were observed for those classified as weak under the body mass [odds ratio (OR) 1.12, CI 0.91-1.36] and body mass index normalized (OR 1.17, CI 0.95-1.43) cut-points. Older Americans below all 3 weakness cut-points had 1.47 (CI 1.15-1.88) greater odds for future cognitive impairment, but no significant associations were found for persons classified as weak under 1 (OR 1.08, CI 0.83-1.42) or 2 (OR 1.19, CI 0.91-1.55) cut-points. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that each weakness cut-point has differential prognostic value for future cognitive impairment, and aggregating weakness cut-points may improve their predictive utility. Consideration should be given to how weakness categories are uniquely linked to cognitive function.

Prevalence and Trends of Handgrip Strength Asymmetry in the United States.

Background: Strength asymmetries are a type of muscle function impairment that is associated with several health conditions. However, the prevalence of these asymmetries among adults from the United States remains unknown. We sought to estimate the prevalence and trends of handgrip strength (HGS) asymmetry in American adults. Methods: The unweighted analytic sample included 23,056 persons aged at least 50-years with information on HGS for both hands from the 2006-2016 waves of the Health and Retirement Study. A handgrip dynamometer measured HGS, with the highest recorded values for each hand used to calculate asymmetry. Persons were categorized into the following asymmetry severity categories: (1) >10%, (2) >20.0%, and (3) >30.0%. Survey weights were used to generate nationally-representative asymmetry estimates. Results: Overall, there were no statistically significant trends in HGS asymmetry categories over time. The prevalence of HGS asymmetry in the 2014-2016 wave was 53.4% (CI: 52.2-54.4), 26.0% (CI: 25.0-26.9), and 11.7% (CI: 10.9-12.3) for asymmetry at >10%, >20%, and >30%, respectively. HGS asymmetry was generally higher in older Americans compared to middle-aged adults at each wave. In the 2014-2016 wave, >30% asymmetry prevalence was 13.7% (CI: 12.7-14.6) in females and 9.3% (CI: 8.4-10.2) in males. Some differences in asymmetry prevalence by race and ethnicity were observed. Conclusions: The prevalence of asymmetry was generally high, especially in women and older adults. Ongoing surveillance of strength asymmetry will help monitor trends in muscle dysfunction, guide screening for disablement, identify subpopulations at risk for asymmetry, and inform relevant interventions.

Physical activity levels among people with fibromyalgia: A systematic review and meta-analysis.

INTRODUCTION: It is unclear how much physical activity (PA) people with fibromyalgia (PwF) engage in. We conducted a meta-analysis to examine PA levels in PwF and compared levels with age- and gender-matched controls and between objective and subjective assessments. METHODS: Embase, PubMed and CINAHL Plus were searched by two independent reviewers from inception till 3 January 2023 using the keywords: 'fibromyalgia' OR 'fibrositis' AND 'physical activity' OR 'exercise' OR 'sports'. A random effects meta-analysis adjusting for publication bias was conducted. RESULTS: Across 22 studies, there were 5997 (5956 women) PwF (median age = 44 years). After trim and fill adjustment, PwF spent a mean of 4.0 (95% CI = 2.3-5.8) min/day in vigorous PA, 67.5 (95% CI = 35.4-99.6) min/day in moderate intensity PA and 270.5 (95% CI = 99.6-441.4) min/day in light PA. Only 37.7% (95% CI = 18.7-61.5) of PwF achieved the public PA recommendation of 150 min of moderate to vigorous PA per week. PwF walked 5663.7 (95% CI = 4493.5-6833.9) steps per day, which is below the 6000 steps per day recommendation. PwF spent 39.0 min/day (95% CI = 22.8-55.1, p < 0.001) less in PA than healthy controls, while MET-minutes per week is 1324.7 (95 % CI = 237.6-2411.7, p = 0.017) lower. There were no significant differences between subjective and objective PA assessments (p = 0.69). CONCLUSION: Our data demonstrate that the majority of PwF are still insufficiently physically active to obtain significant health benefits. Future clinical PA interventions specifically targeting the prevention of physical inactivity in PwF and engaging physically inactive PwF to become physically active are warranted.