Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women

Assessing muscle quality as a key predictor to differentiate fallers from non-fallers in older adults

BACKGROUND

Falling is an important public health issue because of its prevalence and severe consequences. Evaluating muscle performance is important when assessing fall risk. The study aimed to identify factors [namely muscle capacity (strength, quality, and power) and spatio-temporal gait attributes] that best discriminate between fallers and non-fallers in older adults. The hypothesis is that muscle quality, defined as the ratio of muscle strength to muscle mass, is the best predictor of fall risk.

METHODS

184 patients were included, 81% (n = 150) were women and the mean age was 73.6 ± 6.83 years. We compared body composition, mean grip strength, spatio-temporal parameters, and muscle capacity of fallers and non-fallers. Muscle quality was calculated as the ratio of maximum strength to fat-free mass. Mean handgrip and power were also controlled by fat-free mass. We performed univariate analysis, logistic regression, and ROC curves.

RESULTS

The falling patients had lower muscle quality, muscle mass-controlled power, and mean weighted handgrip than the non-faller. Results showing that lower muscle quality increases fall risk (effect size = 0.891). Logistic regression confirmed muscle quality as a significant predictor (p < .001, OR = 0.82, CI [0.74; 0.89]). ROC curves demonstrated muscle quality as the most predictive factor of falling (AUC = 0.794).

CONCLUSION

This retrospective study showed that muscle quality is the best predictor of fall risk, above spatial and temporal gait parameters. Our results underscore muscle quality as a clinically meaningful assessment and may be a useful complement to other assessments for fall prevention in the aging population.

Associations of upper- and lower-limb muscle strength, mass, and quality with health-related quality of life in community-dwelling older adults

AIM

This study aimed to investigate the associations between upper- and lower-limb muscle strength, mass, and quality and health-related quality of life (HRQoL) among community-dwelling older adults.

METHODS

A cross-sectional study was conducted with 428 Brazilian community-dwelling older adults aged 60 to 80 years. Upper- and lower-limb muscle strength were evaluated through the handgrip strength (HGS) test and the 30-s chair stand test, respectively. Muscle mass was assessed by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). Muscle quality was evaluated using the muscle quality index (MQI). HRQoL was assessed using the World Health Organization Quality of Life Brief Version questionnaire.

RESULTS

Lower-limb, but not upper-limb, muscle strength and quality were independently associated with HRQoL, particularly within the domains of physical capacity, environment, and overall HRQoL for both males and females (P < 0.05). DXA- and BIA-derived analyses provided similar results in relation to muscle mass and muscle quality.

CONCLUSIONS

Lower-limb, but not upper-limb, muscle strength and quality were independently associated with HRQoL among community-dwelling older adults. Moreover, the results obtained from both BIA and DXA were similar, highlighting that BIA can serve as a viable surrogate method for estimating body composition in resource-limited clinical settings. Geriatr Gerontol Int 2024; 24: 683-692.

Frontiers in sarcopenia: Advancements in diagnostics, molecular mechanisms, and therapeutic strategies

The onset of sarcopenia is intimately linked with aging, posing significant implications not only for individual patient quality of life but also for the broader societal healthcare framework. Early and accurate identification of sarcopenia and a comprehensive understanding of its mechanistic underpinnings and therapeutic targets paramount to addressing this condition effectively. This review endeavors to present a cohesive overview of recent advancements in sarcopenia research and diagnosis. We initially delve into the contemporary diagnostic criteria, specifically referencing the European Working Group on Sarcopenia in Older People (EWGSOP) 2 and Asian Working Group on Sarcopenia (AWGS) 2019 benchmarks. Additionally, we elucidate comprehensive assessment techniques for muscle strength, quantity, and physical performance, highlighting tools such as grip strength, chair stand test, dual-energy X-ray Absorptiometry (DEXA), bioelectrical impedance analysis (BIA), gait speed, and short physical performance battery (SPPB), while also discussing their inherent advantages and limitations. Such diagnostic advancements pave the way for early identification and unequivocal diagnosis of sarcopenia. Proceeding further, we provide a deep-dive into sarcopenia's pathogenesis, offering a thorough examination of associated signaling pathways like the Myostatin, AMP-activated protein kinase (AMPK), insulin/IGF-1 Signaling (IIS), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Each pathway's role in sarcopenia mediation is detailed, underscoring potential therapeutic target avenues. From a mechanistic perspective, the review also underscores the pivotal role of mitochondrial dysfunction in sarcopenia, emphasizing elements such as mitochondrial oxidative overload, mitochondrial biogenesis, and mitophagy, and highlighting their therapeutic significance. At last, we capture recent strides made in sarcopenia treatment, ranging from nutritional and exercise interventions to potential pharmacological and supplementation strategies. In sum, this review meticulously synthesizes the latest scientific developments in sarcopenia, aiming to enhance diagnostic precision in clinical practice and provide comprehensive insights into refined mechanistic targets and innovative therapeutic interventions, ultimately contributing to optimized patient care and advancements in the field.

A genome-wide association study identifies a locus associated with knee extension strength in older Japanese individuals

Sarcopenia is a common skeletal muscle disease in older people. Lower limb muscle strength is a good predictive value for sarcopenia; however, little is known about its genetic components. Here, we conducted a genome-wide association study (GWAS) for knee extension strength in a total of 3452 Japanese aged 60 years or older from two independent cohorts. We identified a significant locus, rs10749438 which is an intronic variant in TACC2 (transforming acidic coiled-coil-containing 2) (P = 4.2 × 10-8). TACC2, encoding a cytoskeleton-related protein, is highly expressed in skeletal muscle, and is reported as a target of myotonic dystrophy 1-associated splicing alterations. These suggest that changes in TACC2 expression are associated with variations in muscle strength in older people. The association was consistently observed in young and middle-aged subjects. Our findings would shed light on genetic components of lower limb muscle strength and indicate TACC2 as a potential therapeutic target for sarcopenia.

The Impact of Gender-Affirming Hormone Therapy on Physical Performance

CONTEXT

The inclusion of transgender people in elite sport has been a topic of debate. This narrative review examines the impact of gender-affirming hormone therapy (GAHT) on physical performance, muscle strength, and markers of endurance.

EVIDENCE ACQUISITION

MEDLINE and Embase were searched using terms to define the population (transgender), intervention (GAHT), and physical performance outcomes.

EVIDENCE SYNTHESIS

Existing literature comprises cross-sectional or small uncontrolled longitudinal studies of short duration. In nonathletic trans men starting testosterone therapy, within 1 year, muscle mass and strength increased and, by 3 years, physical performance (push-ups, sit-ups, run time) improved to the level of cisgender men. In nonathletic trans women, feminizing hormone therapy increased fat mass by approximately 30% and decreased muscle mass by approximately 5% after 12 months, and steadily declined beyond 3 years. While absolute lean mass remains higher in trans women, relative percentage lean mass and fat mass (and muscle strength corrected for lean mass), hemoglobin, and VO2 peak corrected for weight was no different to cisgender women. After 2 years of GAHT, no advantage was observed for physical performance measured by running time or in trans women. By 4 years, there was no advantage in sit-ups. While push-up performance declined in trans women, a statistical advantage remained relative to cisgender women.

CONCLUSION

Limited evidence suggests that physical performance of nonathletic trans people who have undergone GAHT for at least 2 years approaches that of cisgender controls. Further controlled longitudinal research is needed in trans athletes and nonathletes.

Prevalence of sarcopenia in older women and level of agreement between the diagnostic instruments proposed by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2)

BACKGROUND

The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) proposed the use of different diagnostic tools to assess sarcopenia. This study aimed to determine prevalence rates of sarcopenia according to the diagnostic instruments proposed by EWGSOP2 and to assess their level of agreement in older Brazilian women.

METHODS

A cross-sectional study with 161 community-dwelling older Brazilian women. Probable sarcopenia was assessed through Handgrip Strength (HGS) and the 5-times sit-to-stand test (5XSST). In addition to reduced strength, Appendicular Skeletal Muscle Mass (ASM) (obtained by Dual-energy X-ray absorptiometry) and ASM/height² were considered for diagnosis confirmation. Sarcopenia severity was determined by reduced muscle strength and mass and poor functional performance assessed by Gait Speed (GS), Short Physical Performance Battery (SPPB), and Timed Up and Go test (TUG). McNemar's test and Cochran's Q-test were used to compare sarcopenia prevalence. Cohen's Kappa and Fleiss's Kappa tests were used to assess the level of agreement.

RESULTS

The prevalence of probable sarcopenia was significantly different (p < 0.05) when using HGS (12.8%) and 5XSST (40.6%). Regarding confirmed sarcopenia, the prevalence was lower when using ASM/height² than with ASM. Regarding severity, the use of SPPB resulted in a higher prevalence in relation to GS and TUG.

CONCLUSION

There were differences in the prevalence rates of sarcopenia and low agreement between the diagnostic instruments proposed by the EWGSOP2. The findings suggest that these issues must be considered in the discussion on the concept and assessment of sarcopenia, which could ultimately help to better identify patients with this disease in different populations.

Sphingolipids accumulate in aged muscle, and their reduction counteracts sarcopenia

Age-related muscle dysfunction and sarcopenia are major causes of physical incapacitation in older adults and currently lack viable treatment strategies. Here we find that sphingolipids accumulate in mouse skeletal muscle upon aging and that both genetic and pharmacological inhibition of sphingolipid synthesis prevent age-related decline in muscle mass while enhancing strength and exercise capacity. Inhibition of sphingolipid synthesis confers increased myogenic potential and promotes protein synthesis. Within the sphingolipid pathway, we show that accumulation of dihydroceramides is the culprit disturbing myofibrillar homeostasis. The relevance of sphingolipid pathways in human aging is demonstrated in two cohorts, the UK Biobank and Helsinki Birth Cohort Study in which gene expression-reducing variants of SPTLC1 and DEGS1 are associated with improved and reduced fitness of older individuals, respectively. These findings identify sphingolipid synthesis inhibition as an attractive therapeutic strategy for age-related sarcopenia and co-occurring pathologies.

The Associations between Upper and Lower Body Muscle Strength and Diabetes among Midlife Women

We hypothesized that a combined index of upper and lower body muscle strength would be more strongly associated with diabetes than either measure alone. Women recruited into the Integrated Women's Health Program had their handgrip strength (HGS) measured using a dynamometer and underwent a timed 5-repetition chair stand (RCS) test. HGS < 18 kg and RCS performance ≥ 12 s assessed upper and lower body strength, respectively, both individually and combined in a muscle strength index (MSI). Diabetes was defined as physician-diagnosed, use of anti-diabetic medication, or fasting blood glucose ≥ 7.0 mmol/L. Binary logistic regression examined the associations between muscle strength and diabetes. Of 1170 midlife women, 12.1% had diabetes. A low HGS was independently associated with diabetes (aOR: 1.59, 95% CI: 1.03, 2.44). Prolonged RCS was also associated with diabetes (aOR: 1.59, 95% CI: 1.09, 2.30), but this was not independent of visceral adiposity and muscle mass. A poor MSI had higher odds of diabetes (aOR: 2.37, 95% CI: 1.40, 4.03), independent of age, ethnicity, education level, menopausal status, smoking, alcohol consumption, physical activity, height, visceral adiposity, and muscle mass. The combination of both upper and lower body muscle strength into a composite MSI was more strongly associated with diabetes than either weak HGS or prolonged RCS alone in midlife women.

Is handgrip strength a marker of muscle and physical function of the lower limbs? Sex differences in older adults with obesity

BACKGROUND AND AIMS

In this cross-sectional study we investigate the association between handgrip strength (HGS) and muscle function of the lower limbs and the predictors of the appendicular lean mass index (ALMI) in older adults with obesity of both sexes.

METHODS AND RESULTS

Eighty-four older (67 ± 5 years) men (N = 44) and women (N = 40) with obesity (body mass index (BMI) 33 ± 4 kg/m²) performed: the HGS, isokinetic knee extensors (KE) and flexors (KF) muscle strength and power and Short Physical Performance Battery (SPPB). The correlation between HGS and lower limbs muscle function was evaluated, and four multiple hierarchical linear models were built to assess the contribution of each ALMI predictor (i.e., HGS, BMI, SPPB, muscle strength and power). In men, HGS was weakly-to-moderately associated (p < 0.05) with KE, KF muscle function and physical performance. In women, HGS showed a weak association (p < 0.05) with KE muscle function. The significant predictors of ALMI were only the BMI in women, whereas in the group of men BMI, KE maximal strength and power better explain the variance in ALMI than HGS alone.

CONCLUSION

Our results suggest that HGS should not be used alone as a marker of lower muscle nor physical function. Sex differences exist with the BMI that is a contributor of ALMI both in men and women. However, at least in the group of men, markers related to strength and power of the lower limbs can better describe variations in ALMI compared to HGS in this kind of population.

CLINICAL TRIAL REGISTRATION

NA.

Exploring the association between handgrip, lower limb muscle strength, and physical function in older adults: A narrative review

Widely used in daily practice, handgrip strength (HGS) is a low cost, easy-to-use, and portable test to assess overall muscle and physical function. It can be used as a stand-alone or a first-line tool for evaluating muscle weakness, though controversy surrounds its use for assessing global or lower limb muscle function. Lower limb mobility and physical activity are reduced with advancing age. This decline is difficult to quantify with isokinetic or isometric devices in routine settings (hospital and nursing home). For this narrative review we explored and summarized the findings of studies that investigated the association between HGS, lower limb muscle strength, and physical performance in older adults. The review also provides directions for future research. We noted contrasting findings for an association between HGS, lower limb strength, and physical performance. We found insufficient evidence for endorsing the handgrip dynamometer as a definitive tool for measuring overall muscle strength and physical function. More evidence is needed from comparable studies involving larger samples of men and women and investigating other areas such as lifestyle, daily physical activity levels, and health-related disorders.

Prediction of probable sarcopenia with an alternative method: plantar flexion strength

OBJECTIVE

Sarcopenia is a geriatric syndrome characterized by age-related reduction in muscle mass and strength. Assessment of handgrip strength (HGS) is an essential measurement for the diagnosis of sarcopenia; however, disorders affecting upper limb muscles and joints may pose challenges in assessing handgrip strength. Therefore, the present study aimed to show the validity of plantar flexion strength (PFS) in diagnosing probable sarcopenia and investigating the relations between comprehensive geriatric assessment (CGA) and PFS while determining appropriate cutoff values for PFS.

METHODS

A total of 304 older participans who underwent CGA were included. The revised criteria of the European Working Group on Sarcopenia in Older People (EWGSOP) were used to determine PFS cutoff values for gender groups. Associations between probable sarcopenia and CGA parameters were investigated using PFS cutoffs.

RESULTS

The mean age was 74.50 ± 7.10, and 170 of the participants (55.9%) were women. The mean HGS was 14.40 ± 5.63 kg in women and 25.08 ± 8.07 kg in men. The mean PFS were 13.17 ± 3.62 and 14.92 ± 3.86 kg respectively. In females, PFS cutoff with sensitivity/specificity; 0.81/0.60 was set at 14.95 kg (AUC 0.69, 95%CI: 0.611-0.772, p < 0.001). In males, PFS cutoff with sensitivity/specificity; 0.80/0.55 was set at 16.80 kg (AUC 0.68, 95%CI: 0.593-0.772, p < 0.001). Probable sarcopenia identified by GMS was associated with basic living activities, mobility, and frailty after adjusting for age and sex (p < 0.001, p = 0.021, and p = 0.011 respectively).

CONCLUSIONS

Probable sarcopenia identified by PFS could be associated with CGA. PFS may be useful for evaluating probable sarcopenia in older adults whose HGS cannot be estimated accurately.

Relationship Between Age-Related Changes in Skeletal Muscle Mass and Physical Function: A Cross-Sectional Study of an Elderly Japanese Population

Skeletal muscle mass and muscle strength are positively correlated, but the relationship between grip strength and global muscle strength is controversial. This study aimed to clarify the changes in site-specific skeletal muscle mass by age group and determine the relationship between site-specific, age-related changes in skeletal muscle mass and physical function in community-dwelling elderly people in Japan. The participants were divided into age groups of five-year intervals (65-69 years, 70-74 years, 75-79 years, and ≥80 years) and were also categorized by sex. The skeletal muscle mass of the upper limbs, lower limbs, and trunk was measured using multifrequency bioelectrical impedance analyzers (InBody 430 (Biospace Co., Ltd., Seoul, Korea) and InBody 470 (InBody Japan Inc., Tokyo, Japan)). For physical function assessment, we measured grip strength, quadriceps strength, sit-up count, sit-and-reach distance, and standing time on one leg with eyes open and performed the timed up and go (TUG) test. The results showed that skeletal muscle mass decreased with age regardless of sex at all measured sites. Furthermore, a partial correlation analysis adjusted for age, physical constitution, and the presence/absence of exercise habits revealed that the highest correlation was between skeletal muscle mass in all sites and grip strength. Thus, monitoring grip strength may be used as a representative of systemic skeletal mass even in Japanese people.

Can Muscle Mass Be Maintained with A Simple Resistance Intervention in the Older People? A Cluster Randomized Controlled Trial in Thailand

The aging population is rapidly increasing worldwide. Sarcopenia is a common and important health problem among older people. The prevalence of sarcopenia among older Thai adults is increasing. Exercise intervention for sarcopenia prevention may significantly improve muscle strength, body balance, and muscle mass. Therefore, this study aimed to investigate the effects of a simple resistance intervention (SRI) program in preventing sarcopenia on physiological outcomes among community-dwelling older Thai adults. This study was a 12-week randomized controlled trial, which included 80 community-dwelling older adults in Chiang Mai, Thailand, who were randomly assigned into control (40 participants who performed usual exercise) and intervention (40 participants who performed the SRI program) groups. The SRI program was a home-based program consisting of 30 min of resistance exercise three times/week for 12 weeks, health education on sarcopenia. After 12 weeks, all physiological outcomes were measured and were significantly improved in the intervention group compared with baseline; hand grip, skeletal muscle mass index, and walking speed were significantly improved in the intervention group compared with the control group. Based on our results, the SRI program may prevent muscle weakness in community-dwelling older people in Thailand.

Correlation of grip and knee extension strength in mature adults

BACKROUND AND OBJECTIVE: Grip and knee strength are commonly measured but controversy exists as to whether either is a proxy for the other. The purpose of this meta-analysis was to summarize the correlation between the 2 variables. METHODS: Relevant literature was sought using PubMed, Google, and a hand search. Information on populations, measurements, and correlations were extracted. Correlational data were subjected to meta-analysis. RESULTS: Results from 17 studies were consolidated. The summary correlation between grip and knee extension strength was 0.64 with 95% CI of 0.57 to 0.71. Data were highly heterogeneous but did not show publication bias. CONCLUSION: The correlation between the grip and knee extension strength is good. However, it is not good enough to justify using either as a proxy for the other.

Age-Related Changes in Concentric and Eccentric Isokinetic Peak Torque of the Trunk Muscles in Healthy Older Versus Younger Men

This study investigated age-related changes in trunk muscle function in healthy men and the moderating effect of physical activity. Twelve older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) men performed isokinetic trunk flexion and extension tests across a range of angular velocities (15°/s-180°/s) and contractile modes (concentric and eccentric). For concentric trunk extension, mixed-effects analysis of covariance revealed a significant interaction between Angular velocity × Age group (p = .026) controlling for physical activity. Follow-up univariate analysis of covariance revealed that the younger group produced significantly greater peak torque for all concentric extension conditions. Eccentric trunk strength was somewhat preserved in the older group. Age-related changes in trunk strength were independent of physical activity. The normal loss of trunk muscle strength in older age is muscle- and contractile-mode specific. These findings provide guidance for effective intervention strategies to offset adverse health outcomes related to trunk strength loss in older adults.

Diagnostic dependence of muscle strength measurements and the risk of falls in the elderly

Low muscle strength appears to increase balance disorders and the tendency to fall. Diagnostic terms indicate that sarcopenia and risks of falling are related. The aim of this study is to verify which diagnostic tools used for the assessment of muscle strength in sarcopenia can be used for fall risk assessment in older women. The study included 56 females [71.77 ± 7.43(SD)]. The results of handgrip strength (HGS) and knee extensors torque [knee extension strength (KES)] were compared to the results of stabilographic parameters from Biodex Balance System platform in static and dynamic environment. The one-way ANOVA and Pearson correlation were performed. There were significant differences between groups with low and normal HGS in the chair test, and between groups with low and normal KES in the fall risk index, FRI12-6 and chair test (P < 0.05). Static parameters did not differentiate groups, due to a muscle strength of the upper and lower limbs. There was a statistically significant difference in FRI12-6 values between participants with low and normal KES in age groups (P = 0.047). No differences were found in FRI12-6 values between participants with low and normal HGS in age groups (P = 0.949). Statistical analysis showed differences in FRI12-6 between fallers with low KES and non-fallers with normal KES, non-fallers with low KES and non-fallers with normal KES. Results of the study show that there is diagnostic dependence in muscle strength of lower limbs and risk of falls in older women. KES and chair test can be used in fall risk assessment for older women.

Association between the handgrip strength and the isokinetic muscle function of the elbow and the knee in asymptomatic adults

Background:

The handgrip strength is a practical, valid, reliable, low-cost tool that presents strong correlations with several health conditions. However, handgrip strength may be inaccurate to prospectively predict the variability of muscular function since the decrease in muscular strength over the years varies according to a muscular group or between upper and lower limbs. Our hypothesis is that the handgrip strength cannot explain the variance of muscle function prospectively.

Purpose:

The aim of this study was to evaluate the cross-sectional and prospective association between handgrip strength and isokinetic muscle function of the knee and elbow in 780 asymptomatic adults.

Methods:

In a sample of 780 adults, we obtained handgrip strength and elbow and knee muscle function (for both flexion and extension at 60°/s and 300°/s) using, respectively, a hydraulic dynamometer and an isokinetic dynamometer. In a cross-sectional analysis, we analyzed the data obtained from baseline assessment. Then, we calculated the absolute change as a result of the variation data between the baseline and the 1-year follow-up assessment of each participant. The correlations were analyzed using Pearson or Spearman coefficients. We used multivariate models to investigate the association between handgrip strength and isokinetic muscle function.

Results and Discussion:

The cross-sectional correlations were significantly moderate-to-strong (r = 0.41–0.71, p < 0.01), but became weak-to-moderate (r = 0.26–0.34, p < 0.01) prospectively. In the cross-sectional analysis, the handgrip strength was selected as a strong predictor for isokinetic variables (∆R² = 0.171–0.583, p < 0.05) as expected. Although handgrip strength was also selected as a significant predictor in prospective analysis, it explained only a little variance in isokinetic muscle function of the knee (∆R² = 0.7–0.117, p < 0.05). Regarding the predictive models for the elbow, handgrip strength was not selected prospectively.

Conclusion:

The 1-year absolute change of the handgrip strength cannot explain the variance of the isokinetic muscle function. Thus, specific measures are required for assessing muscle function in epidemiological studies.

Handgrip strength-A risk indicator for type 2 diabetes: Systematic review and meta-analysis of observational cohort studies

AIMS

Evolving debate suggests that handgrip strength (HGS), a measure of muscular strength, might be associated with the risk of type 2 diabetes (T2D); however, the evidence is conflicting. Using a systematic review and meta-analysis of published observational cohort studies in general populations, we aimed to assess the association of HGS with the future risk of T2D.

METHODS

Relevant studies were sought from inception until April 2020 in MEDLINE, Embase, Web of Science, and manual search of relevant articles. Transformed or extracted relative risks (RRs) with 95% confidence intervals (CIs) comparing the top vs bottom thirds of HGS levels were pooled using random effects meta-analysis.

RESULTS

A total of 10 unique observational cohort studies comprising of 177 826 participants and >5167 T2D cases were eligible. The pooled multivariable RR (95% CI) for T2D comparing the top vs bottom thirds of HGS levels was 0.73 (0.63-0.84). This association was consistent across several relevant subgroups except for evidence of effect modification by sample size (P value for meta-regression <.001): evidence of an association in smaller studies (<250 events) 0.50 (0.40-0.63), with no significant association in bigger studies (≥250 events) 0.87 (0.73-1.05). There was no evidence of small study effects using formal tests such as funnel plots and Egger's regression symmetry test.

CONCLUSION

Pooled analysis of observational cohort studies suggests that HGS may be a risk indicator for T2D in the general population. The role of utilizing HGS measurements in T2D prevention strategies warrants further investigation.

Performance on sit-to-stand tests in relation to measures of functional fitness and sarcopenia diagnosis in community-dwelling older adults

BACKGROUND

The sit-to-stand (STS) test has been deployed as surrogate measures of strength or physical performance in sarcopenia diagnosis. This study examines the relationship of two common STS variants - Five Times Sit-to-Stand Test (5TSTS) and 30 s Chair Stand Test (30CST) - with grip strength, muscle mass and functional measures, and their impact on sarcopenia prevalence in community-dwelling older adults.

METHODS

This is a cross-sectional analysis of 887 community-dwelling adults aged ≥50 years. Participants completed a battery of physical fitness tests - 5TSTS, 30CST, grip strength, gait speed, Timed-Up-and-Go (TUG) for dynamic balance and six-minute walk test (6MWT) for cardiorespiratory endurance. Muscle mass was measured using multi-frequency segmental bioelectrical impedance analysis (BIA). We performed correlation analysis between STS performance and other fitness measures and muscle mass, followed by multiple linear regression for the independent determinants of STS performance.

RESULTS

Mean participant age was 67.3±7 years, with female predominance (72.9%). STS tests exhibited weak correlations with grip strength (30CST, r = 0.290; 5TSTS, r = - 0.242; both p< 0.01), and stronger correlations with gait speed (30CST, r = 0.517; 5TSTS, r = - 0.533; both p< 0.01), endurance (30CST, r = 0.558; 5TSTS, r = - 0.531; both p < 0.01) and dynamic balance (30CST, r = - 0.501; 5TSTS, r = 0.646; both p< 0.01). Muscle mass correlated with grip strength but not STS. In multiple regression analysis, all fitness measures were independently associated with 30CST performance. Performance in both STS tests remained independent of muscle mass. There was no significant difference in prevalence of possible sarcopenia diagnosis using grip strength or STS (30CST, 25.0%; 5TSTS, 22.1%; grip strength, 22.3%; p = 0.276). When both measures are used, prevalence is significantly higher (42.0%; p = 0.276). Prevalence of confirmed sarcopenia with inclusion of muscle mass was significantly lower using STS compared with grip strength (30CST, 4.6%; 5TSTS, 4.1% vs. grip strength, 7.1%; p< 0.05).

CONCLUSION

In the sarcopenia construct, STS tests better represents muscle physical performance rather than muscle strength. Different subsets of population with possible sarcopenia are identified depending on the test used. The lack of association of STS performance with muscle mass results in a lower prevalence of confirmed sarcopenia compared with grip strength, but may better reflect changes in muscle quality.

Knee extension strength and handgrip strength are important predictors of Timed Up and Go test performance among community-dwelling elderly women: a cross-sectional study

BACKGROUND

Handgrip and knee extension strengths have each been used to characterize disability. However, it has been reported that the association between handgrip and knee extension strengths is weak.

OBJECTIVE

To evaluate the influence of knee extensor and handgrip muscle strength on Timed Up and Go (TUG) test results among elderly women with worse (≥ 10 seconds) and better (< 10 seconds) performance, after controlling for confounders.

DATA AND SETTING

Cross-sectional study on a sample selected according to convenience, carried out in a federal public institution of higher education.

METHODS

Assessment of handgrip was carried out using the Jamar dynamometer (Lafayette Instrument Company, Inc., Lafayette, United States). Knee extensor muscle performance was measured using an isokinetic dynamometer (Biodex System 3 Pro; Biodex Medical Systems, Inc., United States), The confounding factors were education, age, comorbidities, body mass index and Geriatric Depression Scale and Human Activity Profile scores. Functional performance was assessed through the TUG test. A backward linear regression model was used.

RESULTS

127 elderly women performed the TUG test in more than 10 seconds and 93 in less than 10 seconds. However, regardless of test performance, handgrip strength and knee extension strength comprised the reduced final model.

CONCLUSIONS

Knee extension strength and handgrip strength might be particularly useful indicators for measuring disability.

Comparison of field- and laboratory-based estimates of muscle quality index between octogenarians and young older adults: an observational study

Muscle quality (the ratio of strength to lean muscle mass) might be a better indicator of muscle function than strength alone. Differences in muscle quality index (MQI) between octogenarians and young older adults remain unclear. The aims of the present cross-sectional study were to compare (1) MQI between octogenarians and young older adults, (2) lab versus field-based MQI tools, and (3) determine possible confounding factors affecting MQI in older adults. Compiled data from two cross-sectional studies included 175 younger and older adults (31 men and 144 women) with a mean age of 75.93±9.49 years. Participants with age ≥80 years old were defined as octogenarians (n=79) and <80 years was defined as young older adults (n=96). Laboratory MQI was derived from the ratio of grip strength to arm muscle mass (in kg) measured by dual-energy x-ray absorptiometry. Field-based MQI was quantified from the ratio of grip strength to body mass index (BMI). Octogenarians displayed lower field (P=0.003) and laboratory MQI (P<0.001) as compared with young older adults. There was a strong correlation effect between field MQI and laboratory MQI (P=0.001, R=0.85). BMI (P=0.001), and diabetes mellitus (P=0.001) negatively affected MQI. Women presented lower MQI (P=0.001) values than men. In light of this information, rehabilitation specialists should consider the use of field-based MQI as a tool for evaluation and follow-up of older population.

Is Handgrip Strength a Useful Measure to Evaluate Lower Limb Strength and Functional Performance in Older Women?

Aim

This study aimed to determine the association of handgrip strength with isometric and isokinetic strength (hip, knee and ankle extensor/flexor muscles), and functional capacity in older women.

Methods

The handgrip strength and lower limb strength of 199 older women (60–86 years) were measured using JAMAR and BIODEX dynamometers, respectively. Time Up and Go, Five-times-sit-to-stand and 6m-walk functional tests were evaluated. Pearson correlations were used to determine the relationship between variables. Regression analysis was applied to identify if HS was able to predict TUG performance. The effect of age was analyzed by splitting the participants in a group of older women (OLD; from 60 to 70 years old) and very old women (from 71 to 86 years old).

Results

The HS and isometric/isokinetic strength correlations were negligible/low and, in most cases, were non-significant. The correlation between handgrip strength and functional tests also ranged predominantly from negligible (r=0.0 to 0.3) to low (r=0.3 to 0.5), irrespective of the group age. The handgrip strength was not able to explain the variance of the TUG performance.

Conclusion

Generalizing handgrip strength as a practical and straightforward measure to determine lower limbs and overall strength, and functional capacity in older women must be viewed with caution. Handgrip strength and standard strength measures of the lower limbs and functional tests present a negligible/low correlation.

Low one-repetition-maximum knee extension is significantly associated with poor grip strength, female sex, and various aging-related syndromes

OBJECTIVE

Muscle strength in older adults is usually measured according to grip strength, which demonstrates upper muscle strength only. In this study, we used one-repetition-maximum (1-RM) knee extension as a measure of lower limb strength and assessed its relationship with grip strength and various geriatric syndromes.

METHODS

One hundred outpatients over the age of 65 years were recruited from a geriatric medicine center in India. The 1-RM knee extension was measured along with grip strength. Various geriatric conditions were measured, such as: nutrition (using the Mini Nutritional Assessment), cognition (Hindi Mental State Questionnaire), depression (5-item Geriatric Depression Scale), frailty (Fried and Rockwood models), and osteoporosis (dual-energy X-ray absorptiometry scan). Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

The mean age of participants was 72.5 years with 69% of them male. Median values of 1-RM knee extension and grip strength were 2.29 (0.5-10.0) and 17.5 (0-78), respectively. The 1-RM knee extension had moderate correlation with grip strength (r = 0.491, P < 0.001). Among demographic details, only female sex (P < 0.001) was significantly associated with lower 1-RM values. Further, after adjusting for age and sex, lower value of log10 1-RM knee extension was found to be significantly associated with malnutrition (P = 0.001), dementia (P = 0.016), depression (P = 0.047), frailty (Rockwood: P = 0.049; Fried: P = 0.011), and sarcopenia (P < 0.001).

CONCLUSION

The 1-RM knee extension has only moderate correlation with grip strength. A lower 1-RM knee extension value is significantly associated with female sex and various geriatric conditions, such as malnutrition, dementia, depression, frailty, and sarcopenia.

Influence of Handgrip Stabilization During Isokinetic Knee Strength Assessment in Older Women

The present study aimed to evaluate the influence of holding the chair handles during the assessment of older women's knee flexion and extension isokinetic and isometric strength. Of 57 older women (≥60 years) selected from a convenience sample for this research, 23 were randomly chosen to perform the tests twice for reliability analyses. Each participant performed maximal isokinetic knee extension and flexion at 60°/s and 180°/s angular velocities and isometric tests under two conditions: (a) holding the lateral handle of the chair (HOLD) and (b) supporting the hands on the shoulders with the arms crossed (i.e., not holding the handle [NHOLD]). Participants performed significantly better in the HOLD compared with the NHOLD condition. Slightly lower intraclass correlation coefficients (ICC = 0.870-0.956) were noted for the HOLD than for the NHOLD condition (ICC = 0.900-0.981) so that the HOLD performance on Days 1 and 2 was different on some measures. Owing to the higher reliability coefficients in the NHOLD condition, results suggest that, when assessing knee strength in older women, the evaluee should place their hands over their shoulders with arms crossed in front of the chest (NHOLD) to maximize assessment reliability (reproducibility of performance).

Análise da associação entre força de preensão manual e funcionalidade em pessoas idosas da comunidade

Resumo Objetivo Analisar a associação entre força de preensão manual (FPM) e testes de capacidade física, por parte de pessoas idosas saudáveis, não institucionalizadas. Método Trata-se de uma pesquisa com delineamento transversal. A amostra foi composta por 36 pessoas idosas (66,69±4,84 anos), todos responderam a um instrumento contendo avaliação cognitiva e outro de avaliação do nível de atividade física, além de dados sociodemográficos e condições de saúde. A FPM foi aferida através do dinamômetro hidráulico JAMAR e foram realizados o teste de caminhada de seis minutos (TC6) e o teste Timed Up and Go (TUG) para avaliação da capacidade cardiorrespiratória submáxima durante o deslocamento e a mobilidade corporal. Resultados Foi possível verificar através do coeficiente de Pearson a associação fraca e significativa entre a FPM e as variáveis do TC6 (p=0,05) e TUG (p=0,027). Conclusão A FPM apresentou correlação fraca mas significativa com os testes de capacidade física funcional sendo assim, pode ser usada quando contextualizada com outras variáveis, para avaliar a funcionalidade em pessoas idosas da comunidade.

Grip Strength: An Indispensable Biomarker For Older Adults

Grip strength has been proposed as a biomarker. Supporting this proposition, evidence is provided herein that shows grip strength is largely consistent as an explanator of concurrent overall strength, upper limb function, bone mineral density, fractures, falls, malnutrition, cognitive impairment, depression, sleep problems, diabetes, multimorbidity, and quality of life. Evidence is also provided for a predictive link between grip strength and all-cause and disease-specific mortality, future function, bone mineral density, fractures, cognition and depression, and problems associated with hospitalization. Consequently, the routine use of grip strength can be recommended as a stand-alone measurement or as a component of a small battery of measurements for identifying older adults at risk of poor health status.

Association between hand-grip strength and site-specific risks of major osteoporotic fracture: Results from the Japanese Population-based Osteoporosis Cohort Study

OBJECTIVES

To investigate the association between hand-grip strength and site-specific risks of major osteoporotic fracture.

STUDY DESIGN

Prospective cohort study.

MAIN OUTCOME

Associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip.

MEASURES

We enrolled 1342 postmenopausal women aged 50 years or more into baseline and follow-up surveys of the Japanese Population-based Osteoporosis Cohort Study in 1996, 1999, 2002, or 2006. Fracture events were ascertained by follow-up surveys until 2011 or 2012. The Cox proportional hazards model was used to estimate hazard ratios (HRs) of hand-grip strength on fracture event.

RESULTS

During a median follow-up of 15.2 years, 162 women sustained at least one osteoporotic fracture and 135 of these women sustained at least one major osteoporotic fracture, the larger group including 65, 38, 35, and 8 women with fractures of the distal forearm, vertebrae, hip, and proximal humerus, respectively. In the crude models, the associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip were significant; the HRs (95% confidence interval) of the lowest tertile of hand-grip strength were 2.02 (1.10-3.71), 11.35 (4.07-31.63), and 4.72 (1.79-12.47), respectively. Age adjustment attenuated the significance of hip fracture risk, and adjusting for bone mineral density attenuated the significance of distal forearm fracture risk. After additional adjustment for body mass index, history of diabetes mellitus, and calcium intake, the HR for vertebral fracture risk was 4.55 (1.56-13.27). When limiting the follow-up period to 5 and 10 years, low hand-grip strength was associated with an increased risk of distal forearm fracture independently of the aforementioned covariates; the HRs were 4.22 (1.12-15.95) and 2.52 (1.03-6.17), respectively.

CONCLUSIONS

Low hand-grip strength is specifically associated with the risk of distal forearm fractures within 10 years and clinical vertebral fractures within 15 years or more in Japanese postmenopausal women.

Effects of Protein Intake Beyond Habitual Intakes Associated With Resistance Training on Metabolic Syndrome-Related Parameters, Isokinetic Strength, and Body Composition in Older Women

The objective of this study was to investigate the effects of protein intake beyond habitual intakes associated with resistance training on metabolic syndrome (MetS)-related parameters, isokinetic strength, and body composition in health older women. A total of 30 older women (68.8 ± 4.3 years) participated in this investigation and were assigned to receive 35 g of whey protein or placebo combined with resistance training, over 12-weeks, three times per week. Blood samples, blood pressure, dietary intake, strength, and body composition were assessed before and after the intervention period. Two-way analysis of variance for repeated measures was applied for comparisons. Both groups improved the skeletal muscle mass, muscular strength, waist circumference, triglycerides, high-density lipoprotein, glucose, resistance, reactance, and MetS Z-score risk. However, the improvements in skeletal muscle mass, waist circumference, and MetS Z-score risk were significantly greater in protein group when compared with control group. Moreover, protein group significantly decreased %body fat when compared with control group. Higher protein intake combined with resistance training promoted greater improvements in skeletal muscle mass, %body fat, waist circumference, and MetS Z-score risk in older women.

Timeline of functional recovery after hip fracture in seniors aged 65 and older: a prospective observational analysis

We investigated the timeline of functional recovery after hip fracture over 12 months in adults age ≥ 65 years using objective lower extremity function tests and subjective physical functioning. Objective functional recovery was largely complete in the first 6 months, whereas subjective recovery improved up to 9 months after hip fracture.

INTRODUCTION

Hip fractures are a major cause of loss of function among seniors. We assessed the timeline of objective and subjective functional recovery after hip fracture.

METHODS

We conducted a prospective observational secondary analysis of a 1-year clinical trial on vitamin D and home exercise treatment and complications after hip fracture among 173 patients age ≥ 65 years (mean age 84 years; 79.2% women; 77.4% community-dwelling) conducted from January 2005 through December 2007. Lower extremity function (Timed Up and Go test (TUG), knee extensor and flexor strength) and grip strength was assessed at baseline and at 6 and 12 months follow-up. Subjective physical functioning was assessed using the SF-36 questionnaire also at 3 and 9 months follow-up. Multivariable-adjusted repeated-measures models were used to assess the timeline of functional recovery in the total population and in subgroups of patients.

RESULTS

Lower extremity function including TUG (- 61.1%), knee extensor (+ 17.6%), and knee flexor (+ 11.6%) strength improved significantly in the first 6 months (P < 0.001). However, between 6 and 12 months, there was no further significant improvement for any of the functional tests. Grip strength decreased from baseline to 6 months (- 7.9%; P < 0.001) and from 6 to 12 months (- 10.8%; P < 0.001). Subjective physical functioning improved from 3 to 9 months (+ 15.2%, P < 0.001), but no longer thereafter.

CONCLUSIONS

Functional recovery after hip fracture may be largely complete in the first 6 months for objective functional tests, whereas may extend up to 9 months for subjective recovery, with oldest-old, female, institutionalized, and cognitively impaired patients recovering most poorly.

CLINICAL TRIALS REGISTRY (ORIGINAL TRIAL)

NCT00133640.

Is muscle mechanical function altered in polycystic ovary syndrome?

PURPOSE

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of women of reproductive age. The aim of the current study was to assess muscle mechanical function in PCOS and its relationship with hormonal and metabolic features of the syndrome.

METHODS

The study included 44 women with PCOS, all having clinical or biochemical hyperandrogenism, chronic oligo-anovulation and PCOM, and 32 age- and BMI-matched healthy women. Anthropometric, hormonal and biochemical measurements were performed. Muscle mechanical function including lower limb explosive strength and average power (AvP) was measured using isokinetic dynamometry, a valid and reliable instrument for measuring muscle strength.

RESULTS

The mean age and BMI of the women with PCOS and controls were 21.8 ± 3.2 versus 22.8 ± 3 years and 26.1 ± 5.4 versus 25.5 ± 5.7 kg/m², respectively (p = NS for both). PCOS patients had higher androgen levels, whereas total and regional fat and lean body mass and insulin resistance parameters were similar between the groups. The peak muscle force output defined as the peak torque of knee extensor and flexor muscles was higher in normal weight women compared to overweight and obese (p < 0.05 for both) but did not differ in patients and controls. AvP determined by the time-averaged integrated area under the curve at 60°/s angular velocity was higher in the PCOS group for extension and flexion (50.3 ± 21.2 vs 42.1 ± 11.6 and 35.3 ± 27 vs 22.2 ± 11.1, respectively, p < 0.05 for both). These measurements were correlated with bioavailable testosterone (r = 0.29, p = 0.012, r = 0.36, p = 0.001, respectively).

CONCLUSION

Muscle mechanical function is altered in PCOS. Women with PCOS have increased average lower limb power that is associated with hyperandrogenism.

The Influence of Upper and Lower Extremity Strength on Performance-Based Sarcopenia Assessment Tests

The optimal management of sarcopenia requires appropriate endpoint measures to determine intervention efficacy. While hand grip strength is a predictor of morbidity and mortality, lower extremity strength may be better associated with functional activities in comparison to hand grip strength. The purpose of our study was to examine the comparative association of upper and lower extremity strength with common measures of physical performance in older adults. Thirty community-dwelling men, aged 62.5 ± 9.2 years, completed body composition analysis, quantitative strength testing, and performance-based tests of functional status. Hand grip force values were not significantly associated with knee extensor or flexor torque values (p > 0.05). Hand grip force was only associated with fast gait speed, while knee extensor torque at 60°/s was the only variable significantly associated across all functional outcome measures: customary gait speed, fast gait speed, sit to stand time, and the Physical Performance Test (p < 0.02). Hand grip strength was not a proxy measure of lower extremity strength as assessed in this study. Overall, lower extremity muscle strength values had the strongest associations with participant functional performance. Lower extremity strength testing may provide additional value as an endpoint measure in the assessment and clinical management of sarcopenia.

Get a grip: individual variations in grip strength are a marker of brain health

Demonstrations that grip strength has predictive power in relation to a range of health conditions-even when these are assessed decades later-has motivated claims that hand-grip dynamometry has the potential to serve as a "vital sign" for middle-aged and older adults. Central to this belief has been the assumption that grip strength is a simple measure of physical performance that provides a marker of muscle status in general, and sarcopenia in particular. It is now evident that while differences in grip strength between individuals are influenced by musculoskeletal factors, "lifespan" changes in grip strength within individuals are exquisitely sensitive to integrity of neural systems that mediate the control of coordinated movement. The close and pervasive relationships between age-related declines in maximum grip strength and expressions of cognitive dysfunction can therefore be understood in terms of the convergent functional and structural mediation of cognitive and motor processes by the human brain. In the context of aging, maximum grip strength is a discriminating measure of neurological function and brain health.

Handgrip strength is associated with, but poorly predicts, disability in older women with acute low back pain: A 12-month follow-up study

BACKGROUND

Older women with low back pain (LBP) constitute a special subpopulation at risk of severe and permanent disability. It is important to identify factors limiting functionality in this population in order to reduce costs and improve both prevention and intervention. Handgrip strength (HGS) is a biomarker of aging associated with several adverse health outcomes, but long-term associations with disability in older patients with LBP are not known.

OBJECTIVE

To examine whether HGS predicts disability in older women with acute low back pain (LBP).

METHODS

Longitudinal analyses were conducted with a sample of 135 older women from the international multicenter study Back Complaints in the Elders (BACE-Brazil). Women aged 60 years and over with a new episode of acute LBP were included. HGS was assessed with Jamar^® dynamometer, and disability was assessed using the Roland Morris questionnaire and gait speed test. Variables were assessed at baseline and at 12-month follow-up. Linear regression models explored associations between HGS and disability measures.

RESULTS

Significant association was found between HGS at baseline and gait speed at 12-month follow-up (r=-0.24; p=0.004). A multivariable-adjusted model showed that this association was independent of age, body mass index, and pain intensity (adjusted R²=0.13; p<0.001). A final prediction model showed an incremental difference of only 2.1% in gait speed after inclusion of HGS as an independent variable. No association was found between HGS and score on the Roland Morris questionnaire.

CONCLUSION

Caution is needed regarding the use of HGS as a predictive measure of disability in older women with acute LBP. Changes in gait speed were very small and unlikely to be of clinical relevance.

A cross-sectional study of the association between dynapenia and higher-level functional capacity in daily living in community-dwelling older adults in Japan

Background

There are many reports that dynapenia, sarcopenia and frailty each have associations with bodily function or with Instrumental Activities of Daily Living (IADL). However, studies that compare all three conditions and their effects on IADL are lacking. The purpose of this study is to examine associations of sarcopenia, frailty, and dynapenia with IADL.

Methods

Participants included 123 community-dwelling older adults (31 men, 92 women,) aged 65 years or older (75.0 ± 5.3 years) who were independent in IADL. In terms of physical function, measurements were performed for muscle mass, grip strength, walking speed, isometric knee extension strength, and unipedal standing. A questionnaire survey was carried out, the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) was administered, and participants were asked about sense of fatigue and amount of activity.

Results

Dynapenia was associated with classifications of both frailty and sarcopenia. In addition, sarcopenia had a sensitivity and specificity for dynapenia of 33 and 89%, respectively. Frailty had a sensitivity and specificity for dynapenia of 17 and 98%, respectively. Dynapenia was a significant independent related factor for the TMIG-IC (β = −0.21, P < 0.05).

Conclusions

Dynapenia, more than sarcopenia or frailty, was related to difficulties with IADL; therefore, assessment of dynapenia should be given greater emphasis in evaluating the physical functioning of older adults.

Isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women

AbstractIntroduction The isokinetic dynamometer enables accurate assessment of muscle function. In Brazil, few studies have assessed the isokinetic muscle performance in older adults making interpretation and comparison of results with other studies.Objectives To conduct a descriptive analysis of the performance of the muscle flexor and extensor muscles of the knee joint in elderly community and compare the performance between the age groups 65-74 years and 75 years or more.Methods This is a cross sectional observational study with a convenience sample of 229 elderly community. For the analysis of muscle performance was used isokinetic dynamometer (Biodex System 3 Pro™) in the angular velocities of 60 °/s and 180 °/s. The variables evaluated were peak torque, peak torque normalized by body weight, total work normalized by body mass, total work, average power and agonist/antagonist ratio. Descriptive analysis was used to characterize the sample. For comparison between age groups was used Student's t-test with α = 0.05.Results The elderly women with older age showed a statistically significant decrease in most of the variables (p < 0.05) except for the agonist and antagonist knee (p = 0.398).Conclusions The isokinetic was a sensitive tool to characterize the modifications caused by aging on muscle function. Elderly with results below the lower limits of the confidence intervals for all variables certainly has a decreased strength for the age group evaluated and must be addressed therapeutically. The results can be used as a benchmark in clinical practice and future research.

Prevalência de sarcopenia em idosos: resultados de estudos transversais amplos em diferentes países

ResumoA sarcopenia caracteriza-se pela perda generalizada e progressiva da força e massa muscular esquelética com o envelhecimento. Com o aumento da população idosa em ritmo acelerado em todo o mundo, torna-se necessário o maior entendimento dos fenômenos associados ao processo de envelhecimento. Portanto, descrever a frequência e distribuição desses fenômenos, tal como a sarcopenia, é um passo fundamental para se conhecer os componentes atrelados a sua ocorrência e promover a assistência à saúde direcionada ao idoso. O objetivo desta revisão de literatura foi apresentar a síntese dos resultados de estudos epidemiológicos de base populacional sobre a prevalência de sarcopenia em idosos da comunidade, mostrando também as características sociodemográficas das populações estudadas e a diferença dos resultados entre os sexos. Os resultados de seis estudos transversais, entre os anos 2002 e 2014, provenientes dos seguintes países: Estados Unidos, Reino Unido, Brasil, Japão, Coreia do Sul e Taiwan, foram apresentados. Verificou-se neles que a sarcopenia tem alta prevalência na população a partir dos 60 anos de idade, em ambos os sexos, sendo mais alta nas mulheres em cinco dos seis trabalhos. O Japão foi o país que apresentou as maiores taxas de prevalência, seguido pelo Brasil. A sarcopenia aumentou com a idade em todos os estudos e esteve associada com várias adversidades. A dificuldade em se estabelecer uma avaliação padronizada para sarcopenia, sobretudo pelas peculiaridades de cada população, constitui um importante fator a ser analisado na leitura de estudos de prevalência sobre essa síndrome.

G×E Interaction Influences Trajectories of Hand Grip Strength

Age-related decline in grip strength predicts later life disability, frailty, lower well-being and cognitive change. While grip strength is heritable, genetic influence on change in grip strength has been relatively ignored, with non-shared environmental influence identified as the primary contributor in a single longitudinal study. The extent to which gene-environment interplay, particularly gene-environment interactions, contributes to grip trajectories has yet to be examined. We considered longitudinal grip strength measurements in seven twin studies of aging in the Interplay of Genes and Environment across Multiple Studies consortium. Growth curve parameters were estimated for same-sex pairs, aged 34-99 (N = 10,681). Fisher's test for mixture distribution of within-monozygotic twin-pair differences (N = 1724) was performed on growth curve parameters. We observed significant gene-environment interaction on grip strength trajectories. Finally, we compared the variability of within-pair differences of growth curve parameters by APOE haplotypes. Though not statistically significant, the results suggested that APOE ɛ2ɛ2/ɛ2ɛ3 haplotypes might buffer environmental influences on grip strength trajectories.

The effects of kinesio tape on isokinetic muscular function of horse racing jockeys

[Purpose] The purpose of this study was to conduct a scientific analysis of the effectiveness of Kinesio taping at preventing injury and improving horse racing jockey' performance, by studying the effects on isokinetic muscular function of Kinesio taping applied to the knee joint muscle. [Subjects] Eight horse racing jockeys were selected for this study. [Methods] Measurement of isokinetic muscular function of both flexor and extensor muscles was performed at the angular velocities of 60°/sec and 180°/sec using a Biodex system 3, before and after application of Kinesio taping to the rectus femoris, vastus medialis, vastus lateralis, and hamstring. [Result] At the angular velocities of 60°/sec and 180°/sec, significant differences were observed in both flexor and extensor peak torque, average power, and total work of the knee joint after application of Kinesio taping. [Conclusion] The application of Kinesio taping has a positive effect on the function of both knee flexors and extensors, and also kinetic ability. Therefore, its use would lead to a significant increase in the muscle function of horse racing jockeys.