Physical-strength tests and mortality among visitors to health-promotion centers in Japan

Impact of resistance exercise program on muscle strength, cardiopulmonary function and glycolipid metabolism of bedridden population aged 80 years and above: A randomized controlled trial

BACKGROUND

This study aimed to evaluate the impact of a resistance exercise program in the bedridden older adults in China.

METHODS

The patients aged 80 years and above with stable diseases were randomly divided into control group (receiving routine treatment and nursing) and training group (receiving the elastic ball and elastic band training applied for 55 minutes, 3 times a week during 6 months).

RESULTS

A total of 59 patients (control group: 30; training groups: 29) completed the study. In terms of muscle strength, the patients of the training group had better grip strength and supine leg lifts and 30-s sit-to-stand actions. In terms of cardiopulmonary function and glycolipid metabolism, the patients in the training groups had better lung capacity and high-density lipoprotein.

CONCLUSION

The low-load and low-intensity resistance training may effectively improve not only the muscle strength of the bedridden older adults, but also the lung function and blood lipid metabolism.

Association between physical fitness tests and neuromuscular properties

PURPOSE

While various fitness tests have been developed to assess physical performances, it is unclear how these tests are affected by differences, such as, in morphological and neural factors. This study was aimed to investigate associations between individual differences in physical fitness tests and neuromuscular properties.

METHODS

One hundred and thirty-three young adults participated in various general physical fitness tests and neuromuscular measurements. The appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. Echo intensity (EI) was evaluated from the vastus lateralis. During submaximal knee extension force, high-density surface electromyography of the vastus lateralis was recorded and individual motor unit firings were detected. Y-intercept (i-MU) and slope (s-MU) from the regression line between the recruitment threshold and motor unit firing rate were calculated.

RESULTS

Stepwise multiple regression analyses revealed that knee extension strength could be explained (adjusted R2 = 0.712) by ASM (β = 0.723), i-MU (0.317), EI (- 0.177), and s-MU (0.210). Five-sec stepping could be explained by ASM (adjusted R2 = 0.212). Grip strength, side-stepping, and standing broad jump could be explained by ASM and echo intensity (adjusted R2 = 0.686, 0.354, and 0.627, respectively). Squat jump could be explained by EI (adjusted R2 = 0.640). Counter-movement jump could be explained by EI and s-MU (adjusted R2 = 0.631). On the other hand, i-MU and s-MU could be explained by five-sec stepping and counter-movement jump, respectively, but the coefficients of determination were low (adjusted R2 = 0.100 and 0.045).

CONCLUSION

Generally developed physical fitness tests were mainly explained by morphological factors, but were weakly affected by neural factors involved in performance.

Handgrip strength of young athletes differs based on the type of sport played and age

OBJECTIVE

Handgrip strength may differ depending on the type of sport played during the developmental period. Youth sports in which athletes hold equipment in their hands may be the most effective for improving handgrip strength. This study aimed to examine the age at which differences in handgrip strength appear by comparing sports that involve gripping (kendo) with those that do not involve gripping (soccer) in young athletes.

METHODS

Two hundred and twenty-two male athletes (115 kendo and 107 soccer) between 6 and 15 years old participated in this study. Handgrip strength was measured using a dynamometer, and the average value of both hands was used for analysis. Sports experience was determined when they started practicing each sport. Handgrip strength was compared between sports. Statistical moderation was used to determine if the relationship between sport and handgrip strength depended upon the age of the athlete.

RESULTS

Kendo athletes had significantly higher handgrip strength than soccer athletes (4.77 kg [95% CI: 2.34, 7.19]) in the overall sample. We found that the relationship between sport and handgrip strength depended upon the age of the child (sport*age t = -3.6, p = .004). Using the Johnson-Neyman procedure, we found statistically significant differences between sports from 8.48 years and older.

CONCLUSIONS

Our results suggest that the type of sport played, that is, whether or not an athlete plays with sports equipment in their hands, may influence the development of handgrip strength during the period of growth, and these sports may contribute to a higher level of handgrip strength in adulthood.

Physical performance and negative events in very old adults: a longitudinal study examining the ilSIRENTE cohort

BACKGROUND

Declining physical performance in old age is associated with a wide range of negative health-related outcomes. However, it is unclear which physical capabilities should be prioritized to obtain prognostic information in older adults.

AIMS

To examine the associations between the performance on several physical function tests and falls, disability, and death in a well-characterized sample of very old Italian adults.

METHODS

This was a prospective cohort study of older adults who lived in the mountain community of the Sirente geographic area in Central Italy. Physical performance was assessed using isometric handgrip strength (IHG), walking speed (WS) at a usual and fast pace, 5-time sit-to-stand test (5STS), and sit-to-stand power measures. Appendicular skeletal muscle mass was estimated from calf circumference using a validated equation. History of falls, incident falls, and disability status according to basic Activities of Daily Living (ADLs) were recorded over two years. Survival status was obtained from the participants' general practitioners and was confirmed by the National Death Registry over 10 years from enrolment. Linear, binary, and Cox regressions were performed to evaluate the association between physical performance measures and health outcomes.

RESULTS

The mean age of the 255 participants was 84.2 ± 5.1 years, and 161 (63.1%) were women. Logistic regression indicated that IHG was significantly associated with incident ADL disability, whereas specific sit-to-stand muscle power was an independent predictor of death. No significant associations were observed between physical function and falls.

CONCLUSIONS

Our findings indicate selective associations between physical function tests and the occurrence of negative events in very old adults, with poor IHG predicting disability and specific sit-to-stand muscle power being longitudinally associated with death.

One-Year Handgrip Strength Change in Kindergarteners Depends upon Physical Activity Status

Free play in kindergarten can be roughly divided into fine and gross motor activities, but the effects of these activities on improving handgrip strength are unknown. Therefore, we aimed to compare one-year changes in handgrip strength and forearm flexor muscle size in children separated by preferred play in a kindergarten. One hundred and eleven children were recruited from a local kindergarten. They underwent handgrip strength and forearm muscle thickness measurements, and 95 (49 boys and 46 girls) underwent a second measurement one year after the first measurement. Class teachers assessed the physical activity of everyone in their class after the second measurement. Using three evaluation scores by the class teachers, we divided children into three groups based on the children's preference to play in kindergarten (fine movement vs. gross motor movement). Handgrip strength did not change differently between groups across one year. However, children who liked active playing outside (i.e., gross motor activity) were stronger than others. Furthermore, children who like playing outside observed greater changes than the other groups in the ulna (right hand) and radius muscle thickness (left hand), suggesting that changes in forearm muscle size might be incongruent with changes in handgrip strength among the three activity groups.

Handgrip strength is associated with risks of new-onset stroke and heart disease: results from 3 prospective cohorts

BACKGROUND

Stroke and heart disease are two major contributors to the global disease burden. We aimed to evaluate and compare the roles of different handgrip strength (HGS) expressions in predicting stroke and heart disease in three nationally representative cohorts.

METHODS

This longitudinal study used data from the Health and Retirement Study (HRS), the Survey of Health, Ageing, and Retirement in Europe (SHARE), and the China Health and Retirement Longitudinal Study (CHARLS). The Cox proportional hazard model was applied to analyze the relationship between HGS and stroke and heart disease, and Harrell's C index was used to assess the predictive abilities of different HGS expressions.

RESULTS

A total of 4,407 participants suffered from stroke and 9,509 from heart disease during follow-up. Compared with the highest quartile, participants in the lowest quartile of dominant HGS, absolute HGS and relative HGS possessed a significantly higher risk of new-onset stroke in Europe, America, and China (all P < 0.05). After adding HGS to office-based risk factors, there were minimal or no differences in the increases of Harrell's C indexes among three HGS expressions. In contrast, the modest association between HGS and heart disease was only seen in SHARE and HRS, but not in CHARLS.

CONCLUSION

Our findings support that HGS can be used as an independent predictor of stroke in middle-aged and older European, American and Chinese populations, and the predictive ability of HGS may not depend on how it is expressed. The relationship between HGS and heart disease calls for further validation.

Thresholds of handgrip strength for all-cause, cancer, and cardiovascular mortality: A systematic review with dose-response meta-analysis

BACKGROUND

While handgrip strength is associated with all-cause and cause-specific mortality, whether such associations are dose-dependent is largely unknown. Therefore, we conducted a systematic review on the dose-response relationship of handgrip strength with all-cause mortality, cancer, and cardiovascular mortality.

METHODS

The data source included three electronic databases (PubMed/MEDLINE, Web of Science and Scopus) from inception to 8 February 2022. Prospective cohort studies of healthy adults with objective measures of handgrip strength were included. Two researchers independently screened studies, extracted data, and assessed risk of bias. We used estimates regarding handgrip strength categories to conduct a random forest model, and a two-stage random-effects hierarchical meta-regression model pooling study-specific estimates for dose-response relationship. Outcomes included all-cause, cancer, and cardiovascular mortality.

REULTS

Forty-eight studies comprising 3,135,473 participants (49.6% women, age range 35-85 years) were included. Random forest models showed a significant inverse association between handgrip strength and all-cause and cause-specific mortality. Dose-response meta-analyses showed that higher levels of handgrip strength significantly reduced the risk of all-cause mortality within 26-50 kg (Higgin´s I² =45.7%) in a close-to-linear inverse fashion. Cancer and cardiovascular mortality displayed a trend towards a U-shaped association with a significant risk reduction between 16 and 33 kg (Higgin´s I² =77.4%), and a close-to-linear inverse shaped and significant risk reduction ranging from 24 to 40 kg (Higgin´s I² =79.7%) respectively.

CONCLUSION

There is strong evidence for an association between lower handgrip strength with higher all-cause, cancer, and cardiovascular mortality risk. The dose-response relationship of handgrip strength substantially varies depending on the cause of mortality.

Duration of Daytime Napping Is Related to Physical Fitness among Chinese University Students

Reportedly, daytime napping affects the physical fitness of athletes. However, results of these studies are conflicting, and may not be generalizable to all populations. Early adulthood is an important period linking adolescents and adults, during which building good physical fitness is crucial for their remaining lives. Thus, we investigated whether daytime napping duration is associated with physical fitness among Chinese university students. This study was based on an annual physical health examination for all university students and included 11,199 participants (6690 males; 4509 females). The daytime napping duration was assessed using a self-report questionnaire. Physical fitness was measured with a 50 m sprint; 1000 m (for males) and 800 m (for females) runs; standing long jump, sit-and-reach, pull-up (for males), and sit-up (for females) tests; and vital capacity. The adjusted association was evaluated using analysis of covariance. Of the participants, 86% napped regularly. After covariate adjustment was performed, significant V-shaped associations were observed between the daytime napping duration and the 50 m sprint and 800 m run results in males and females. Inverted V-shaped associations were observed between the daytime napping duration and the sit-and-reach, standing long jump, and pull-up test performances and vital capacity in males and between the daytime napping duration and the standing long jump test performance in females. Daytime napping for <30 min may have beneficial effects on physical fitness among university students.

Association of Handgrip Strength in Various Disabilities in Korean Adults over 50 Years Old: A Nationwide Cross-Sectional Study

Several studies have shown an association between low hand grip strength (HGS) and functional limitations. This study aims to elucidate the association between HGS and functional limitations. We used the nationwide health examination data and included 13,517 Korean adults that were aged ≥ 50 years. We measured HGS using digital dynamometer and the maximum value of the dominant hand was divided into quartiles for the analysis. Functional limitations were assessed by using self-administered questionnaires. We categorized the 24 reported causes of functional limitations into musculoskeletal, cardiometabolic, neuropsychiatric, cancers, and others. In multiple regression analysis, the functional limitations tended to increase as HGS was lowered in both sexes. When analyzing according to the reasons of functional limitations, the ORs for functional limitations due to cardiometabolic problem tended to increase as the HGS decreased in men (p for trend = 0.039). Similar trends were observed in neuropsychiatric problem in women (p for trend = 0.002) and other problems in both men and women (p for trend = 0.014 in men, p for trend = 0.004 in women). No significant trends were observed for musculoskeletal problems and cancer in both men and women. The functional limitations were inversely associated with HGS, which were inconsistent according to different etiologies of functional limitations.

Impact of relative muscle power on hospitalization and all-cause mortality in older adults

BACKGROUND

The purpose of this study was to evaluate the relationship of lower-limb muscle power with mortality and hospitalization.

METHODS

A total of 1928 subjects from the Toledo Study for Healthy Aging were included. Muscle power was assessed with the 5-repetition STS test and subjects were classified into different groups of relative power (i.e. normalized to body mass) according to sex-specific tertiles and their inability to perform the test. Mean follow-up periods for hospitalization and all-cause mortality were 3.3 and 6.3 years, respectively.

RESULTS

Compared to the high relative muscle power group, men with low (HR [95%CI]= 2.1 [1.2-3.6]) and women with very low and low (HR [95%CI]= 4.7 [3.0-7.4] and 1.8 [1.2-2.7]) relative power had an increased age-adjusted risk of hospitalization. After adjusting for several covariates (age, physical activity, BMI education, depression, comorbidities, disability and handgrip strength) these effects were attenuated (men and women with very low relative power: HR [95%CI]= 1.6 [0.9-2.9] and 2.8 [1.6-4.9]). The very low relative muscle power group had also an increased all-cause mortality risk (age-adjusted) in both men and women (HR [95%CI]= 2.3 [1.4-3.9] and 2.9 [1.6-5.3]). After adjusting for all the covariates, a significantly increased mortality risk was observed only in men (HR [95% CI]= 2.1 [1.1-3.8], (women HR [95% CI]= 1.6 [0.8-3.2]), with very low levels of relative power.

CONCLUSION

Relative muscle power was independently and negatively associated with mortality and hospitalization in older adults. An augmented all-cause mortality risk was noted in the lowest group of relative muscle power.

Association Between Low Handgrip Strength and 90-Day Mortality Among Older Chinese Inpatients: A National Multicenter Prospective Cohort Study

Background: The knowledge of the association between low handgrip strength and mortality among older Chinese inpatients is limited. Given China's aging society, a great number of older adults require hospital admission. Objective: To explore the association between low handgrip strength and 90-day mortality, providing evidence for clinicians to predict the risk of mortality and improve clinical outcomes for older inpatients. Materials and Methods: We conducted a national multicenter cohort study with a baseline survey from October 2018 to February 2019 and followed up for 90 days to record mortality outcomes. The assessment of handgrip strength was conducted using a hand dynamometer with the cutoff (handgrip strength < 28 kg for men and < 18 kg for women) to define low handgrip strength. Multivariable logistic regression analysis was applied to explore the association between low handgrip strength and 90-day mortality. Results: A total of 8,910 older Chinese inpatients [mean (SD) age, 72.39 (5.68) years; 3,750 women (42.09%)], with a prevalence of low handgrip strength, at 49.57%, were included. Compared to inpatients with normal handgrip strength, inpatients with low handgrip strength were older, had less education, more were female, had lower activities of daily living (ADL) score, had lower BMI, higher frailty, higher rates of depression, and poorer cognitive function (all p < 0.05). At 90 days, after adjusting for gender, age, education, frailty, depression, ADL score, malnutrition, and diagnosis, low handgrip strength was independently associated with 90-day mortality, compared to normal handgrip strength (OR = 1.64, 95% CI:1.14-2.37; P = 0.008). Additionally, subgroup and interaction analysis showed a significant interaction effect (P = 0.031) between two age groups (65-74 years older vs. ≥ 75 years old), with the OR being 3.19 (95%CI:2.07-4.93) and 1.49 (95%CI:0.87-2.55), respectively. Conclusion: Older Chinese inpatients with low handgrip strength had a 1.64-fold risk of 90-day mortality, compared to those with normal handgrip strength, indicating that clinicians need to screen early for handgrip strength and recommend corresponding interventions, such as resistance training and nutrition, as a priority for older inpatients. Clinical Trial Registration: Chinese Clinical Trial Registry, Identifier: ChiCTR1800017682.

Accuracy of isolated nutrition indicators in diagnosing malnutrition and their prognostic value to predict death in patients with gastric and colorectal cancer: A prospective study

BACKGROUND

The study aims to evaluate the accuracy of isolated nutrition indicators in diagnosing malnutrition in patients with gastric and colorectal cancer and their association with mortality.

METHODS

Prospective cohort study involving patients with cancer (n = 178) attending a reference center of oncology at any point in the disease trajectory or treatment. Nutrition status was evaluated in a unique moment by body mass index (BMI), Patient-Generated Subjective Global Assessment (PG-SGA), handgrip strength (HGS), and calf circumference (CC). Kappa coefficient, accuracy, sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) were calculated for each nutrition indicator (PG-SGA as the reference method). The Cox proportional hazards model was used to assess hazard ratio (HR) and CI of mortality.

RESULTS

From the total patients, 11% were underweight, 48% were malnourished (PG-SGA B or C), 43% had low HGS, and 55% presented low CC. There were 46 deaths (25.8%). BMI, HGS, and CC showed poor and fair agreements (κ < 0.30 for all ) and poor accuracy (AUC < 0.70 for all) in identifying malnutrition by PG-SGA. After the adjustment for confounders (age, treatment performed, site, and stage of cancer), PG-SGA (HR, 2.9; 95% CI, 1.5-5.9) and low CC (HR, 2.4; 95% CI, 1.1-5.2) were independent predictors of mortality.

CONCLUSION

The nutrition indicators are not accurate in diagnosing malnutrition, whereas PG-SGA and low CC could predict mortality in gastric and colorectal cancer patients. Thus, CC should be combined with PG-SGA in nutrition assessments.

The Case for Retiring Flexibility as a Major Component of Physical Fitness

Flexibility refers to the intrinsic properties of body tissues that determine maximal joint range of motion without causing injury. For many years, flexibility has been classified by the American College of Sports Medicine as a major component of physical fitness. The notion flexibility is important for fitness has also led to the idea static stretching should be prescribed to improve flexibility. The current paper proposes flexibility be retired as a major component of physical fitness, and consequently, stretching be de-emphasized as a standard component of exercise prescriptions for most populations. First, I show flexibility has little predictive or concurrent validity with health and performance outcomes (e.g., mortality, falls, occupational performance) in apparently healthy individuals, particularly when viewed in light of the other major components of fitness (i.e., body composition, cardiovascular endurance, muscle endurance, muscle strength). Second, I explain that if flexibility requires improvement, this does not necessitate a prescription of stretching in most populations. Flexibility can be maintained or improved by exercise modalities that cause more robust health benefits than stretching (e.g., resistance training). Retirement of flexibility as a major component of physical fitness will simplify fitness batteries; save time and resources dedicated to flexibility instruction, measurement, and evaluation; and prevent erroneous conclusions about fitness status when interpreting flexibility scores. De-emphasis of stretching in exercise prescriptions will ensure stretching does not negatively impact other exercise and does not take away from time that could be allocated to training activities that have more robust health and performance benefits.

Relationships Between Eating Behaviors and Hand Grip Strength Among Chinese Adults: A Population-Based Cross-Sectional Study

Purpose

Poor eating behaviors are associated with imbalances in energy and food intake, which may directly or indirectly contribute to muscle strength loss. This study aimed to investigate the association between eating behaviors and hand grip strength in Chinese adults.

Materials and Methods

We designed and conducted a cross-sectional study of 2009 Chinese individuals aged 25–65 years in 2017. Eating behaviors, including breakfast consumption, snacking after dinner, and eating rate, were assessed using a self-administered questionnaire. Hand grip strength was assessed using a digital grip dynamometer. Age, sex, BMI, physical activity, educational level, occupation, living status, sleep duration, smoking and drinking status, hypertension, diabetes, and depressive symptoms were used as confounding factors.

Results

After final adjustments for confounding factors, grip strength was measured as 35.2 (95% confidence interval [CI]: 34.7–35.8), 36.0 (95% CI: 35.6–36.4), and 36.9 (95% CI: 36.6–37.3) for those who skipped, occasionally ate, and regularly ate breakfast, respectively (p for trend <0.001). Those who always, sometimes, and seldom snacked after dinner (p for trend <0.001) reported the following grip strength: 34.7 (95% CI: 34.0–35.3), 36.2 (95% CI: 35.8–36.6), and 36.9 (95% CI: 36.6–37.2), respectively. Significant associations were not found between eating rate and grip strength.

Conclusion

This study showed that higher frequency of breakfast consumption and lower frequency of snacking after dinner were associated with higher grip strength in Chinese adults. Therefore, eating behaviors may be involved in muscle function.

Changes in Muscle Mass and Composition by Exercise and Hypoxia as Assessed by DEXA in Mice

Background and Objective: Skeletal muscle is critical for overall health and predicts quality of life in several chronic diseases, thus quantification of muscle mass and composition is necessary to understand how interventions promote changes in muscle quality. The purpose of this investigation was to quantify changes in muscle mass and composition in two distinct pre-clinical models of changes in muscle quality using a clinical dual X-ray absorptiometry (DEXA), validated for use in mice. Materials and Methods: Adult C57Bl6 male mice were given running wheels (RUN; muscle hypertrophy) or placed in hypobaric hypoxia (HH; muscle atrophy) for four weeks. Animals received weekly DEXA and terminal collection of muscle hind limb complex (HLC) and quadriceps weights and signaling for molecular regulators of muscle mass and composition. Results: HH decreased total HLC muscle mass with no changes in muscle composition. RUN induced loss of fat mass in both the quadriceps and HLC. Molecular mediators of atrophy were upregulated in HH while stimulators of muscle growth were higher in RUN. These changes in muscle mass and composition were quantified by a clinical DEXA, which we described and validated for use in pre-clinical models. Conclusions: RUN improves muscle composition while HH promotes muscle atrophy, though changes in composition in hypoxia remain unclear. Use of the widely available clinical DEXA for use in mice enhances translational research capacity to understand the mechanisms by which atrophy and hypertrophy promote skeletal muscle and overall health.

Phase Angle as a Marker of Muscular Strength in Breast Cancer Survivors

BACKGROUND

accurate prognostic tools are relevant for decision-making in cancer care. Objective measures, such as bioelectrical impedance (BI), have the potential to improve prognostic accuracy for these patients. This cross-sectional study aimed to investigate whether phase angle (PhA) derived from the electrical properties of the body tissues is a predictor of muscular strength in breast cancer survivors (BCS).

METHODS

a total of 41 BCS (age 54.6 ± 9.2 years) were evaluated. PhA, obtained at frequency 50 kHz, was assessed with BI spectroscopy, and muscular strength with a handgrip dynamometer. Moderate-to-vigorous physical activity (MVPA) was assessed using the International Physical Activity Questionnaire (IPAQ). Measurements were performed in the morning after an overnight fast.

RESULTS

linear regression analysis showed that PhA accounted for 22% (r² = 0.22) of muscular strength variance. PhA remained a borderline predictor of muscular strength variance independently of age and MVPA.

CONCLUSIONS

the findings of this study suggest that PhA is a significant predictor of maximal forearm isometric strength and a potential indicator of disease-related functionality in BCS.

Five-year change in maximum tongue pressure and physical function in community-dwelling elderly adults

Background/purpose

To identify age-related changes in maximum tongue pressure (MTP), it is necessary to determine individual biological age. The fitness age score (FAS) is used to calculate the biological age, based on the one-leg standing time with eyes open, vertical jump height, grip strength, functional reach, and 10-m walk time.

Materials and methods

The study included 112 community-dwelling elderly adults (42 males and 70 females). We investigated MTP, FAS, and body mass index (BMI) at baseline and 5 years later. MTP was determined with a pressure measurement device.

Results

A significant reduction in MTP, FAS, and BMI in both male and female subjects was observed at 5 years. A negative correlation between change in MTP and baseline MTP was observed, but there was no correlation between MTP change and baseline FAS, BMI, and change in FAS and BMI.

Conclusion

Age-related decline in MTP might be associated with high MTP, reflecting decreased reserve. Additionally, age-related decline in tongue function might be different from that of physical function.

Do Nationally Representative Cutpoints for Clinical Muscle Weakness Predict Mortality? Results From 9 Years of Follow-up in the Health and Retirement Study

BACKGROUND

Muscle weakness, as measured by handgrip strength, is associated with cardiovascular and all-cause mortality; however, there are wide inconsistencies in the magnitude of these effects due to divergent definitions used to define muscle weakness across studies. Therefore, the objective of this study was to examine the relationship between previously defined sex- and race-specific cutpoints of clinical muscle weakness and early mortality.

METHODS

Data come from the 2006-2014 Health and Retirement Study. Time-varying clinical muscle weakness, as defined by handgrip strength cutpoints, was the primary exposure. Time to death, ascertained from the National Death Index, was the outcome of interest. The association between time-varying clinical muscle weakness and early mortality across a 9-year observation period was determined using Kaplan-Meier methods and extended Cox regression.

RESULTS

Out of the 8,326 individuals in the study, 1,799 deaths (21%) occurred during the observation period. Median follow-up time was 8.3 years (SD ±1.9 years). Weak individuals had a steeper decline in their survival trajectory, compared to non-weak individuals (Log-Rank test, p < .001). After adjusting for sociodemographic factors and time-varying smoking history, weak individuals were over 50% more likely to die earlier than non-weak individuals (hazard ratio [HR] = 1.52, 95% confidence interval [CI] = 1.15, 1.47).

CONCLUSIONS

This is the first study to use muscle weakness cutpoints derived in a nationally representative sample to identify those individuals who may be at greatest risk for premature mortality. Results underscore the importance of muscle weakness, as defined by handgrip strength, as a key risk factor for premature mortality in older Americans.

Birth weight and grip strength in young Swedish males: a longitudinal matched sibling analysis and across all body mass index ranges

Low birth weight is associated with a lower grip strength later in life. However, associations between birth weight among infants born at-term and factors driving associations between birth weight and grip strength are largely unknown. A cohort of 144,369 young men born at-term, including 10,791 individuals who had at least one male sibling/s, were followed until conscription where they performed a grip strength test. We used linear and non-linear regression analyses in the full cohort, and fixed-effects regression analyses in the sibling cohort, to address confounding by factors that are shared between siblings. After adjustment, each unit increase in birth weight z-score was associated with increases of 17.7 (95% CI, 17.2–18.2) and 13.4 (10.1–16.6) newton grip strength, which converts to approximately 1.8 and 1.4 kilogram-force in the full and within-families cohorts, respectively. The associations did not vary with young adulthood BMI. Birth weight, within the at-term range, is robustly positively associated with grip strength in young adulthood among men across all BMI categories and associations appears to be mainly driven by factors that are not shared between siblings. These findings underline the importance of recognizing the influence of low birth weight, also within the at-term-range, on young adulthood muscle strength.

Association of health empowerment and handgrip strength with intention to participate in physical activity among community-dwelling older adults

INTRODUCTION

Health empowerment is an individual's perceived control and competence related to health and health care. The projected increased growth of the older adult population calls for a health-related empowerment movement in health education that targets older adults. Using the theory of planned behavior, the purpose of this study was to investigate the association of health empowerment and handgrip strength with intention to participate in physical activity among older adults.

METHODS

The Korean Health Empowerment Scale (K-HES) was used as a measure of health empowerment. Handgrip strength was used as a measure of muscle strength. Intention to participate in physical activity was measured using five items. Participants of this study included 103 community-dwelling older adults (Mage = 76.45 ± 9.395; Male = 42, Female = 61).

RESULTS

Statistical analyses revealed all participants were knowledgeable about the health benefits of exercise and most participated in regular physical activity (n = 84.5%). The majority had normal handgrip strength (n = 60.7%) and most indicated strong intentions to participate in regular physical activity (n = 85%). A stepwise multiple regression revealed health empowerment significantly and positively (F(1,101) = 30.511, p < .001, R² = 0.232, R²_Adjusted = 0.224) associated intention to participate in physical activity. Health empowerment explained 23.2% of the variance in intentions. There was no significant contribution of muscle strength on intention.

DISCUSSION

Findings suggest overall health empowerment may be affected by a variety of subscales such as problem-solving, obtaining support, motivation, psychosocial coping, and decision making.

CONCLUSION

Future research should explore potential associations between health empowerment and intention to participate in physical activity.

A Cross-National Study of the Gender Gap in Health Among Older Adults in India and China: Similarities and Disparities

Background and Objectives

The present cross-sectional study examines gender differences in three major health measures among older adults in India and in China, and investigates whether these differences can be explained by major sociodemographic and health risk characteristics.

Research Design and Methods

The study included 7,150 individuals in India and 13,367 individuals in China aged 50-plus who participated in the WHO Study on Global AGEing and Adult Health in 2007-2010. Logistic regression models for self-reported health (SRH) and ordinary least square regression models for grip strength and cognitive function were used to investigate gender differences in health.

Results

A consistent female disadvantage was found in India and in China for all three health measures. Compared to their male counterparts, women in the Indian and the Chinese samples had, respectively, 38% (95% confidence interval [CI]: 1.22, 1.56) and 36% (95% CI: 1.25, 1.48) higher risk of reporting poor SRH, 9.56 kg (95% CI: 9.91, 9.22) and 11.95 kg (95% CI: 12.29, 11.62) lower grip strength, and 3.64 (95% CI: 3.96, 3.32) and 1.99 (95% CI: 2.28, 1.71) lower cognitive scores. The magnitude of the female disadvantage in poor SRH and in grip strength changed very little when adjustments were made for marital status, education, place of residence, smoking status, height, and number of chronic conditions; but these characteristics accounted for about 50% of the gender gap in cognitive function.

Discussion and Implications

In these study populations, major sociodemographic and health risk characteristics accounted for very small parts of the gender differences in health, except in cognition.

Relative importance of four functional measures as predictors of 15-year mortality in the older Dutch population

BACKGROUND

Decreased physical function is known to raise mortality risk. Little is known about how different physical function measures compare in predicting mortality risk in older men and women. The objective of this study was to compare four, objective and self-reported, physical function measures in predicting 15-year mortality risk in older men and women.

METHODS

Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a population-based sample of the older Dutch population, sampled from municipal records. The 1995-96 cycle, including 727 men and 778 women aged 65-88 years, was considered as the baseline. Mortality was followed up through September 1, 2011. Physical function measures were: lower-body performance (chair stands test, walk test and tandem stand); handgrip strength (grip strength dynamometer); lung function (peak expiratory flow rate); functional limitations (self-report of difficulties in performing six activities of daily living). Cox proportional hazard models were used to determine the predictive value of each physical function measure for 15-year mortality risk, adjusted for demographic, lifestyle and health variables as potential confounders.

RESULTS

1031 participants (68.5%) had died. After adjustments for confounders, in models assessing single functional measures, peak flow was the strongest predictor of all-cause mortality in men (HR 1.76, CI 1.38-2.26, CI) and lower-body performance in women (HR 1.97,CI 1.40-2.76, CI). In a model including all four functional measures only peak flow was statistically significant in predicting mortality in both genders (men HR 1.54,CI 1.18-2.01 and women HR 1.45,CI 1.08-1.94). In women, lower-body performance (HR 1.66, CI 1.15-2.41) followed by grip strength (HR 1.38, CI 1.02-1.89), and in men, functional limitations (HR 1.43, CI 1.14-1.8) were the other significant predictors of all-cause mortality.

CONCLUSION

Both objective and self-reported measures of physical functioning predicted all-cause mortality in a representative sample of the older Dutch population to different extents in men and women. Peak flow contributed important unique predictive value for mortality in both men and women. In women, however, lower-body performance tests had better predictive ability. A second-best predictor in men was self-reported functional limitations. Peak flow, and possibly one of the other measures, may be used in clinical practice for assessment in the context of time constraints.

Repressors of mTORC1 act to blunt the anabolic response to feeding in the soleus muscle of a cast-immobilized mouse hindlimb

We recently reported results showing that cast immobilization of a rat hindlimb rapidly leads to development of anabolic resistance as demonstrated by failure of oral leucine administration to activate the mechanistic target of rapamycin complex 1 (mTORC1) and stimulate protein synthesis in the soleus muscle. The goal of this study was to assess the possible contribution of several mTORC1 regulatory proteins to the development of anabolic resistance. To accomplish this, 14-week-old male C57BL/6 mice (n = 21) were subjected to unilateral cast immobilization of the hindlimb for either 1 or 3 days, and the immobilized limb was compared to its contralateral control. The mass of the soleus muscle was decreased in the immobilized compared to the non-immobilized limb within 72-h in association with diminished protein synthesis. In agreement with our previous report, a 24-h casting period was sufficient to induce anabolic resistance, as demonstrated by blunted re-feeding-induced activation of mTORC1. Moreover, resistance of mTORC1 activation was associated not only with upregulated expression of REDD1, but also with altered expression of other mTORC1 regulatory proteins, that is, Sestrin1 and DEP domain-containing mTOR interacting protein (DEPTOR). In addition, re-feeding-induced phosphorylation of DEPTOR was significantly impaired in the immobilized compared to the non-immobilized limb. This work builds upon previous discoveries by our laboratory to elucidate the blunted mTORC1 response to stimuli during disuse of skeletal muscle induced by cast immobilization while highlighting new potential therapeutic targets for future countermeasures against muscle atrophy.

Concurrent Criterion Validity of a Test of Usual Gait Speed in Older Adults

Usual gait speed has been shown to have very good reliability and convincing predictive validity for evaluating older adults' gait skills, but its criterion validity is unknown. We examined the criterion validity of the 8-feet (i.e., 2.44 meters) test in a laboratory environment to assess usual gait speed by comparing its results with the Intelligent Device for Energy Expenditure and Activity (IDEEA) monitor. Participants were 200 well-functioning community-dwelling adults aged 65 and older (113 women; 87 men; mean [M] age = 71.8, standard deviation [ SD] = 5.6 years). Participants wore the IDEEA monitor for 48 consecutive hours, and we used the participants' average usual gait speed for the analysis. The Spearman correlation of usual gait speed using both the 8-feet test and IDEEA monitor was moderate and statistically significant (ρ = .364, p < .001). The mean difference between both methods was 0.20 ( SD = 0.27) meters/second, and the corresponding limits of agreement were 0.73 and -0.33 meters/second. There was a small systematic bias when the difference between the two methods was correlated with usual gait speed as measured by the IDEEA (ρ = -.20, p = .011). The perfect agreement (weighted kappa) of both instruments for classifying usual gait speed into tertiles, quartiles, and quintiles was 48.3% ( k = 0.17), 30.9% ( k = 0.23), and 25.4% ( k = 0.29), respectively. Our results indicate that the 8-feet test showed moderate criterion-related validity for evaluating and assessing usual gait speed test in older adults.

Combined Aerobic and Resistance Training Effects on Glucose Homeostasis, Fitness, and Other Major Health Indices: A Review of Current Guidelines

The combination of aerobic and resistance training (AER + RES) is recommended by almost every major organization to improve health-related risk factors associated with sedentary behavior. Since the release of the Physical Activity Guidelines for Americans in 2008, several large well-controlled trials and ancillary reports have been published that provide further insight into the effects of AER + RES on health-related outcomes. The current manuscript examines the literature on the effects of AER + RES on major clinical outcomes, including glucose homeostasis, cardiorespiratory fitness (CRF), and muscular strength, as well as other important clinical outcomes, including metabolic syndrome, hypertension, dyslipidemia, and quality of life. Collectively, research suggests that AER + RES and AER or RES alone improves glycemic control and insulin sensitivity compared with continued sedentary behavior. Significant changes in CRF are also observed, suggesting a reduction in cardiovascular disease-related mortality risk. Reduced adiposity, especially abdominal adiposity, and increased strength may also interact with CRF to promote additional health benefits associated with AER + RES. While findings from our review support current physical activity guidelines, a paucity of research limits the generalizability of the results.

Role of Dietary Protein and Muscular Fitness on Longevity and Aging

Muscle atrophy is an unfortunate effect of aging and many diseases and can compromise physical function and impair vital metabolic processes. Low levels of muscular fitness together with insufficient dietary intake are major risk factors for illness and mortality from all causes. Ultimately, muscle wasting contributes significantly to weakness, disability, increased hospitalization, immobility, and loss of independence. However, the extent of muscle wasting differs greatly between individuals due to differences in the aging process per se as well as physical activity levels. Interventions for sarcopenia include exercise and nutrition because both have a positive impact on protein anabolism but also enhance other aspects that contribute to well-being in sarcopenic older adults, such as physical function, quality of life, and anti-inflammatory state. The process of aging is accompanied by chronic immune activation, and sarcopenia may represent a consequence of a counter-regulatory strategy of the immune system. Thereby, the kynurenine pathway is induced, and elevation in the ratio of kynurenine to tryptophan concentrations, which estimates the tryptophan breakdown rate, is often linked with inflammatory conditions and neuropsychiatric symptoms. A combined exercise program consisting of both resistance-type and endurance-type exercise may best help to ameliorate the loss of skeletal muscle mass and function, to prevent muscle aging comorbidities, and to improve physical performance and quality of life. In addition, the use of dietary protein supplementation can further augment protein anabolism but can also contribute to a more active lifestyle, thereby supporting well-being and active aging in the older population.

Is retirement good for men's health? Evidence using a change in the retirement age in Israel

This study examines the effect of employment on elderly men's health. A typical OLS analysis yields a positive relationship between employment and health for individuals in their sixties. Causality, however, is difficult to infer because healthier individuals are more capable of working than others. To overcome this endogeneity problem, this paper exploits the increase in the full retirement age for men in Israel from sixty-five to sixty-seven in 2004. After this change, the employment rate of men in this age bracket jumped significantly compared to the last cohort that was able to retire at sixty-five. Using the new retirement law as an exogenous source of variation in the employment status of elderly men, a significant causal relationship in the opposite direction of the correlation is found: employment at older ages impairs health. These findings are found across a broad array of datasets and health outcomes. The results are significantly stronger among less-educated workers, suggesting that employment in physically demanding occupations is more detrimental to health. Placebo analyses using the years preceding the new retirement regime and other health measures unrelated to employment (e.g., dentist visits) reinforce a causal interpretation of my main findings.

Cancer-Specific Mortality Relative to Engagement in Muscle-Strengthening Activities and Lower Extremity Strength

BACKGROUND

Skeletal muscle strength and engagement in muscle-strengthening activities are each inversely associated with all-cause mortality; however, less is known on their relationship with cancer-specific mortality.

METHODS

Data from the 1999-2002 National Health and Nutrition Examination Survey were used assessing 2773 individuals aged 50 years or older. Individuals being dichotomized at the 75th percentile for knee extensor strength, and engagement in muscle-strengthening activities was acquired through self-report with ≥2 sessions per week were classified as meeting guidelines.

RESULTS

With respect to cancer-specific mortality, individuals in the upper quartile for muscle strength were at a 50% reduced risk (hazard ratio = 0.50; 95% confidence interval, 0.29-0.85; P = .01) and those meeting muscle-strengthening activities were at a nonsignificant 8% reduced risk (hazard ratio = 0.92; 95% confidence interval, 0.45-1.86, P = .81) of cancer-specific mortality after adjusting for covariates.

CONCLUSIONS

Clinicians should routinely assess lower extremity strength and promote engagement in muscle-strengthening activities aimed at increasing muscle strength.

Unilateral lower limb strength assessed using the Nintendo Wii Balance Board: a simple and reliable method

BACKGROUND

Lower limb weakness is an important risk factor for fall accidents and a predictor for all-cause mortality among older adults. Unilateral whole-lower limb strength may be a better measure of fall risk than the bilateral measure. In addition, a number of clinical conditions affect only one leg, and thus this type of assessment is relevant in clinical settings.

AIM

To explore the intra-rater reproducibility of the Nintendo Wii Balance Board (WBB) to measure unilateral whole-lower limb strength and to compare the method with stationary isometric muscle apparatus (SID).

METHOD

Intra-rater test-retest design with 1 week between sessions. Thirty community-dwelling older adults (69 ± 4.2 years) were enrolled and examined for maximum lower limb strength in their dominant and non-dominant leg. Intraclass correlation coefficient (ICC) was calculated to describe relative reproducibility, while standard error of measurement (SEM), limits of agreement (LOA) and smallest real difference (SRD) were calculated to describe absolute reproducibility between test sessions. Concurrent validity with the SID was explored using the Pearson product-moment correlation coefficient (PCC).

RESULTS

No systematic difference was observed between test sessions. ICC was 0.919-0.950 and SEM, LOA and SRD was 2.9-4.1 kg, 24.1-28.3 kg and 7.6-11.3 kg, respectively. Further, the PCC was 0.755 and 0.730 for the dominant limb and the non-dominant limb, respectively.

CONCLUSION

A high relative and an acceptable absolute reproducibility was seen when using the Nintendo Wii Balance Board for testing unilateral lower limb strength in community-dwelling older adults. The WBB correlated strongly with the SID.

Handgrip strength and its prognostic value for mortality in Moscow, Denmark, and England

Background

This study compares handgrip strength and its association with mortality across studies conducted in Moscow, Denmark, and England.

Materials

The data collected by the Study of Stress, Aging, and Health in Russia, the Study of Middle-Aged Danish Twins and the Longitudinal Study of Aging Danish Twins, and the English Longitudinal Study of Ageing was utilized.

Results

Among the male participants, the age-standardized grip strength was 2 kg and 1 kg lower in Russia than in Denmark and in England, respectively. The age-standardized grip strength among the female participants was 1.9 kg and 1.6 kg lower in Russia than in Denmark and in England, respectively. In Moscow, a one-kilogram increase in grip strength was associated with a 4% (hazard ratio [HR] = 0.96, 95% confidence interval [CI]: 0.94, 0.99) reduction in mortality among men and a 10% (HR = 0.90, 95%CI: 0.86, 0.94) among women. Meanwhile, a one-kilogram increase in grip strength was associated with a 6% (HR = 0.94, 95%CI: 0.93, 0.95) and an 8% (HR = 0.92, 95%CI: 0.90, 0.94) decrease in mortality among Danish men and women, respectively, and with a 2% (HR = 0.98, 95%CI: 0.97, 0.99) and a 3% (HR = 0.97, 95%CI: 0.95, 0.98) reduction in mortality among the English men and women, respectively.

Conclusion

The study suggests that, although absolute grip strength values appear to vary across the Muscovite, Danish, and English samples, the degree to which grip strength is predictive of mortality is comparable across national populations with diverse socioeconomic and health profiles and life expectancy levels.

Functional capacities of Polish adults of 60-87 years and risk of losing functional independence

AIM

To characterise the functional capacities of Polish men and women aged 60-87 years and evaluate their status relative to criteria for functional independence.

SUBJECTS AND METHODS

Four hundred and thirty-one women and 125 men, aged 60-87 years, who were residents of Wrocław, southwestern Poland, were recruited. Height and weight were measured and BMI was calculated. The Fullerton Functional Fitness Test was administered to test upper and lower body strength, upper and lower body flexibility, agility-dynamic balance and aerobic endurance. The Paffenbarger physical activity questionnaire was completed. Characteristics of individuals classified by the number of tests which equalled or exceeded criterion-referenced standards for functional independence (excluding flexibility) were compared.

RESULTS

Polish older adults compared favourably to American reference values. Percentages meeting the criteria for all four, for two or three and for one or no tests were, respectively, 21%, 54% and 25% in women and 37%, 45% and 18% in men. Adults meeting the criteria for all four tests were lighter, with a lower BMI and more physically active than those meeting the criteria on two or three tests and on one or no tests.

CONCLUSION

The majority of Polish older adults were not at risk for loss of physical independence. The most functionally independent adults of both sexes had a lower BMI and less obesity, and were physically more active; the converse was true for those not meeting the criteria.

No association between grip strength and cardiovascular risk: The CoLaus population-based study

BACKGROUND

Decreased grip strength (GS) is predictive of cardiovascular (CV) disease but whether it improves CV risk prediction has not been evaluated. We assessed the predictive value of low GS on incident CV events and overall mortality taking into account CV risk equations in a population-based study from Switzerland.

METHODS

2707 adults (54.8% women, age range 50-75years) were followed for a median time of 5.4years. GS was assessed using a hydraulic hand dynamometer. CV absolute risk at baseline was assessed using recalibrated SCORE, Framingham and PROCAM risk equations. Incident CV events were adjudicated by an independent committee.

RESULTS

160 deaths and 188 incident CV events occurred during follow-up. On bivariate analysis, low GS was associated with increased incident CV events: hazard ratio (HR) and (95% confidence interval) 1.76 (1.13-2.76), p<0.01 but not with overall mortality: HR=1.51 (0.94-2.45), p=0.09. The association between low GS and incident CV events disappeared after adjusting for baseline CV risk: HR=1.23 (0.79-1.94), p=0.36; 1.34 (0.86-2.10), p=0.20 and 1.47 (0.94-2.31), p=0.09 after adjusting for SCORE, Framingham and PROCAM scores, respectively.

CONCLUSION

Low GS is not predictive of incident CV events when taking into account CV absolute risk.

Reference ranges of handgrip strength from 125,462 healthy adults in 21 countries: a prospective urban rural epidemiologic (PURE) study

BACKGROUND

The measurement of handgrip strength (HGS) has prognostic value with respect to all-cause mortality, cardiovascular mortality and cardiovascular disease, and is an important part of the evaluation of frailty. Published reference ranges for HGS are mostly derived from Caucasian populations in high-income countries. There is a paucity of information on normative HGS values in non-Caucasian populations from low- or middle-income countries. The objective of this study was to develop reference HGS ranges for healthy adults from a broad range of ethnicities and socioeconomically diverse geographic regions.

METHODS

HGS was measured using a Jamar dynamometer in 125,462 healthy adults aged 35-70 years from 21 countries in the Prospective Urban Rural Epidemiology (PURE) study.

RESULTS

HGS values differed among individuals from different geographic regions. HGS values were highest among those from Europe/North America, lowest among those from South Asia, South East Asia and Africa, and intermediate among those from China, South America, and the Middle East. Reference ranges stratified by geographic region, age, and sex are presented. These ranges varied from a median (25^th-75^th percentile) 50 kg (43-56 kg) in men <40 years from Europe/North America to 18 kg (14-20 kg) in women >60 years from South East Asia. Reference ranges by ethnicity and body-mass index are also reported.

CONCLUSIONS

Individual HGS measurements should be interpreted using region/ethnic-specific reference ranges.

Gender differences in the association between grip strength and mortality in older adults: results from the KORA-age study

Background

Reduced muscular strength in the old age is strongly related to activity impairment and mortality. However, studies evaluating the gender-specific association between muscularity and mortality among older adults are lacking. Thus, the objective of the present study was to examine gender differences in the association between muscular strength and mortality in a prospective population-based cohort study.

Methods

Data used in this study derived from the Cooperative Health Research in the Region of Augsburg (KORA)-Age Study. The present analysis includes 1,066 individuals (mean age 76 ± 11 SD years) followed up over 3 years. Handgrip strength was measured using the Jamar Dynamometer. A Cox proportional hazard model was used to determine adjusted hazard ratios of mortality with 95% confidence intervals (95% CI) for handgrip strength. Potential confounders (i.e. age, nutritional status, number of prescribed drugs, diseases and level of physical activity) were pre-selected according to evidence-based information.

Results

During the follow-up period, 56 men (11%) and 39 women (7%) died. Age-adjusted mortality rates per 1,000 person years (95% CI) were 77 (59–106), 24 (13–41) and 14 (7–30) for men and 57 (39–81), 14 (7–27) and 1 (0–19) for women for the first, second and third sex-specific tertile of muscular strength, respectively. Low handgrip strength was significantly associated with all-cause mortality among older men and women from the general population after controlling for significant confounders. Hazard ratios (95% CI) comparing the first and second tertile to the third tertle were 3.33 (1.53–7.22) and 1.42 (0.61-3.28), respectively. Respective hazard ratios (95% CI) for mortality were higher in women than in men ((5.23 (0.67–40.91) and 2.17 (0.27–17.68) versus 2.36 (0.97–5.75) and 0.97 (0.36–2.57)).

Conclusions

Grip strength is inversely associated with mortality risk in older adults, and this association is independent of age, nutritional status, number of prescribed drugs, number of chronic diseases and level of physical activity. The association between muscular strength and all-cause mortality tended to be stronger in women. It seems to be particularly important for the weakest to enhance their levels of muscular strength in order to reduce the risk of dying early.

Objective measures of the frailty syndrome (hand grip strength and gait speed) and cardiovascular mortality: A systematic review

BACKGROUND

Handgrip strength (HGS) and gait speed (GS) are objective components of the frailty syndrome in the elderly, and are associated with increased all-cause mortality. However, their association with cardiovascular (CVD) mortality is less lucid. The present systematic review aims to summarize the available literature assessing HGS, GS and their association with CVD Mortality.

METHODS

Medline and Embase databases were searched systematically using controlled vocabulary and free text terms. A total of 344 results were obtained and scanned for inclusion. Articles were included if they presented results of original research and provided information on HGS or GS and CVD mortality.

RESULTS

A total of 19 studies (N=63,396) were included for review. Twelve studies examined hand grip strength with CVD mortality and 7 studies assessed gait speed. Almost all included studies demonstrated an association of HGS/GS with CVD mortality on univariate analyses. Decreased HGS or GS were associated with increased mortality in most studies (8/12 for HGS and 6/7 for GS). In most positive studies, the association of HGS/GS was usually found to be independent of traditional CVD risk factors.

CONCLUSION

The present review demonstrates that decreased HGS and GS are associated with CVD mortality, with the association found to be more consistent for GS as compared to HGS. Both of these measures provide valuable prognostic information above and beyond traditional scoring methods and should be considered for implementation in clinical practice.

Longitudinal development of manual motor ability in autism spectrum disorder from childhood to mid-adulthood relates to adaptive daily living skills

Many individuals with autism spectrum disorder (ASD) exhibit motor difficulties, but it is unknown whether manual motor skills improve, plateau, or decline in ASD in the transition from childhood into adulthood. Atypical development of manual motor skills could impact the ability to learn and perform daily activities across the life span. This study examined longitudinal grip strength and finger tapping development in individuals with ASD (n = 90) compared to individuals with typical development (n = 56), ages 5 to 40 years old. We further examined manual motor performance as a possible correlate of current and future daily living skills. The group with ASD demonstrated atypical motor development, characterized by similar performance during childhood but increasingly poorer performance from adolescence into adulthood. Grip strength was correlated with current adaptive daily living skills, and Time 1 grip strength predicted daily living skills eight years into the future. These results suggest that individuals with ASD may experience increasingly more pronounced motor difficulties from adolescence into adulthood and that manual motor performance in ASD is related to adaptive daily living skills.

Isometric hand grip strength measured by the Nintendo Wii Balance Board - a reliable new method

BACKGROUND

Low hand grip strength is a strong predictor for both long-term and short-term disability and mortality. The Nintendo Wii Balance Board (WBB) is an inexpensive, portable, wide-spread instrument with the potential for multiple purposes in assessing clinically relevant measures including muscle strength. The purpose of the study was to explore intrarater reliability and concurrent validity of the WBB by comparing it to the Jamar hand dynamometer.

METHOD

Intra-rater test-retest cohort design with randomized validity testing on the first session. Using custom WBB software, thirty old adults (69.0 ± 4.2 years of age) were studied for reproducibility and concurrent validity compared to the Jamar hand dynamometer. Reproducibility was tested for dominant and non-dominant hands during the same time-of-day, one week apart. Intraclass correlation coefficient (ICC) and standard error of measurement (SEM) and limits of agreement (LOA) were calculated to describe relative and absolute reproducibility respectively. To describe concurrent validity, Pearson's product-moment correlation and ICC was calculated.

RESULTS

Reproducibility was high with ICC values of >0.948 across all measures. Both SEM and LOA were low (0.2-0.5 kg and 2.7-4.2 kg, respectively) in both the dominant and non-dominant hand. For validity, Pearson correlations were high (0.80-0.88) and ICC values were fair to good (0.763-0.803).

CONCLUSION

Reproducibility for WBB was high for relative measures and acceptable for absolute measures. In addition, concurrent validity between the Jamar hand dynamometer and the WBB was acceptable. Thus, the WBB may be a valid instrument to assess hand grip strength in older adults.

Determining the Importance of Meeting Muscle-Strengthening Activity Guidelines: Is the Behavior or the Outcome of the Behavior (Strength) a More Important Determinant of All-Cause Mortality?

OBJECTIVE

To determine whether the behavioral participation in muscle-strengthening activity (MSA) or the strength outcome produces the largest reduction in all-cause mortality risk.

PATIENTS AND METHODS

The 1999-2002 National Health and Nutritional Examination Survey was used, with follow-up of up to 12.6 years (mean, 9.9 years) (N=2773 adults aged ≥50 years). Participants were placed into 4 groups based on 2 dichotomously categorized variables: lower-extremity strength (LES) of the knee extensors (top quartile) and adherence to MSA guidelines (≥2 MSA sessions per week). Approximately 21% of the population died during follow-up.

RESULTS

Compared with individuals not meeting MSA guidelines and not in top quartile for LES, the adjusted hazard ratios (HRs) and 95% CIs were as follows: (1) meets MSA guidelines but not in top quartile for LES (HR=0.96; 95% CI, 0.63-1.45; P=.84), (2) in top quartile for LES but does not meet MSA guidelines (HR=0.54; 95% CI, 0.42-0.71; P<.001), and (3) in top quartile for LES and meets MSA guidelines (HR=0.28; 95% CI, 0.12-0.66; P=.005). Further analyses revealed that individuals in the top quartile for LES who also met MSA and moderate to vigorous physical activity guidelines were at even further reduced risk for premature all-cause mortality (HR=0.23; 95% CI, 0.08-0.61; P=.005).

CONCLUSION

These results demonstrate that muscle strength seems to be more important than the behavioral participation in MSA for reducing the risk of premature all-cause mortality.

Prognostic value of grip strength: findings from the Prospective Urban Rural Epidemiology (PURE) study

BACKGROUND

Reduced muscular strength, as measured by grip strength, has been associated with an increased risk of all-cause and cardiovascular mortality. Grip strength is appealing as a simple, quick, and inexpensive means of stratifying an individual's risk of cardiovascular death. However, the prognostic value of grip strength with respect to the number and range of populations and confounders is unknown. The aim of this study was to assess the independent prognostic importance of grip strength measurement in socioculturally and economically diverse countries.

METHODS

The Prospective Urban-Rural Epidemiology (PURE) study is a large, longitudinal population study done in 17 countries of varying incomes and sociocultural settings. We enrolled an unbiased sample of households, which were eligible if at least one household member was aged 35-70 years and if household members intended to stay at that address for another 4 years. Participants were assessed for grip strength, measured using a Jamar dynamometer. During a median follow-up of 4.0 years (IQR 2.9-5.1), we assessed all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, myocardial infarction, stroke, diabetes, cancer, pneumonia, hospital admission for pneumonia or chronic obstructive pulmonary disease (COPD), hospital admission for any respiratory disease (including COPD, asthma, tuberculosis, and pneumonia), injury due to fall, and fracture. Study outcomes were adjudicated using source documents by a local investigator, and a subset were adjudicated centrally.

FINDINGS

Between January, 2003, and December, 2009, a total of 142,861 participants were enrolled in the PURE study, of whom 139,691 with known vital status were included in the analysis. During a median follow-up of 4.0 years (IQR 2.9-5.1), 3379 (2%) of 139,691 participants died. After adjustment, the association between grip strength and each outcome, with the exceptions of cancer and hospital admission due to respiratory illness, was similar across country-income strata. Grip strength was inversely associated with all-cause mortality (hazard ratio per 5 kg reduction in grip strength 1.16, 95% CI 1.13-1.20; p<0.0001), cardiovascular mortality (1.17, 1.11-1.24; p<0.0001), non-cardiovascular mortality (1.17, 1.12-1.21; p<0.0001), myocardial infarction (1.07, 1.02-1.11; p=0.002), and stroke (1.09, 1.05-1.15; p<0.0001). Grip strength was a stronger predictor of all-cause and cardiovascular mortality than systolic blood pressure. We found no significant association between grip strength and incident diabetes, risk of hospital admission for pneumonia or COPD, injury from fall, or fracture. In high-income countries, the risk of cancer and grip strength were positively associated (0.916, 0.880-0.953; p<0.0001), but this association was not found in middle-income and low-income countries.

INTERPRETATION

This study suggests that measurement of grip strength is a simple, inexpensive risk-stratifying method for all-cause death, cardiovascular death, and cardiovascular disease. Further research is needed to identify determinants of muscular strength and to test whether improvement in strength reduces mortality and cardiovascular disease.

FUNDING

Full funding sources listed at end of paper (see Acknowledgments).

Physical Fitness Evaluation

Physical fitness is simply defined as the capacity to perform physical work. Energy is necessary to perform work and sustain life and is extracted aerobically and anaerobically. Evaluation of aerobic fitness is based on the assessment of maximal oxygen consumption (Vo2 max), either directly or indirectly. Direct assessment of Vo2 max is usually determined by a graded exercise test using open circuit spirometry. Indirect assessments of Vo2 max use standardized exercise protocols. Such protocols can also be used to estimate Vo2 max with the subject exercising at submaximal heart rate levels. These estimates are based on the linear relationship between exercise heart rate and O2 consumption. Walking and step tests that allow an estimate of fitness based on exercise and recovery heart rate responses are also available. Evaluation of anaerobic power consists of 30 to 120 seconds of high-intensity effort on a cycle ergometer, known as the Wingate test. Muscular strength is assessed by a maximum effort against the greatest resistance one can move through the full range of motion once, known as the 1-repetition maximum. Muscular endurance is assessed by tests requiring more than 12 repetitions, or the maximum number of push-ups or sit-ups one can execute without rest.

Muscular strength as a strong predictor of mortality: A narrative review

Muscular strength, an important component of physical fitness, has an independent role in the prevention of chronic diseases whereas muscular weakness is strongly related to functional limitations and physical disability. Our purpose was to investigate the role of muscular strength as a predictor of mortality in health and disease. We conducted a systematic search in EMBASE and MEDLINE (1980-2014) looking for the association between muscular strength and mortality risk (all-cause and cause-specific mortality). Selected publications included 23 papers (15 epidemiological and 8 clinical studies). Muscular strength was inversely and independently associated with all-cause mortality even after adjusting for several confounders including the levels of physical activity or even cardiorespiratory fitness. The same pattern was observed for cardiovascular mortality; however more research is needed due to the few available data. The existed studies failed to show that low muscular strength is predictive of cancer mortality. Furthermore, a strong and inverse association of muscular strength with all-cause mortality has also been confirmed in several clinical populations such as cardiovascular disease, peripheral artery disease, cancer, renal failure, chronic obstructive pulmonary disease, rheumatoid arthritis and patients with critical illness. However, future studies are needed to further establish the current evidence and to explore the exact independent mechanisms of muscular strength in relation to mortality. Muscular strength as a modifiable risk factor would be of great interest from a public health perspective.

Acceleration training for improving physical fitness and weight loss in obese women

BACKGROUND

Reducing body weight and visceral adipose tissue (VAT) are the primary goals for maintaining health in obese individuals as compared to those of normal weight, but it is also important to maintain physical fitness for a healthy life after weight-loss. Acceleration training (AT) has recently been indicated as an alternative to resistance training for elite athletes and also as a component of preventive medicine. However, it is unclear whether combining AT with a weight-loss diet will improve physical fitness in obese individuals. The present study aimed to determine the synergistic effects of AT on body composition and physical fitness with weight-loss program in overweight and obese women.

METHODS

Twenty-eight obese, middle-aged women were divided into two groups as follows: diet and aerobic exercise group (DA; BMI: 29.3 ± 3.0 kg/m2); and diet, aerobic exercise and acceleration training group (DAA; BMI: 31.2 ± 4.0 kg/m2). Both groups included a 12-week weight-loss program. Body composition, visceral adipose tissue (VAT) area and physical fitness (hand grip, side-to-side steps, single-leg balance with eyes closed, sit-and-reach and maximal oxygen uptake) were measured before and after the program.

RESULT

Body weight, BMI, waist circumference and VAT area decreased significantly in both groups. Hand grip (2.1 ± 3.0 kg), single-leg balance (11.0 ± 15.4 s) and sit-and-reach (6.5 ± 4.8 cm) improved significantly only in the DAA group.

CONCLUSIONS

Our findings indicate that combining AT with classical lifestyle modifications is effective at reducing VAT, and it may enhance muscle strength and performance in overweight and obese women.

Midlife and late-life handgrip strength and risk of cause-specific death in a general Japanese population: the Hisayama Study

BACKGROUND

Decreased handgrip strength has been reported to be a risk factor for all-cause death among the elderly. However, it is unclear whether handgrip strength measured in midlife is associated with risk of all-cause and cause-specific death in the general population.

METHODS

We followed, prospectively, a total of 2527 community-dwelling Japanese (1064 men and 1463 women) aged ≥40 years for 19 years. Participants were divided into three groups according to the age-specific and sex-specific tertiles of handgrip strength (T1, lowest; T3, highest).

RESULTS

During the follow-up period, 783 participants died, of whom 235 died of cardiovascular disease, 249 of cancer, 154 of respiratory disease and 145 of other causes. In the middle-aged group (40-64 years), multivariable-adjusted HRs (95% CIs) for all-cause death were 0.75 (0.56 to 0.99) in T2 and 0.49 (0.35 to 0.68) in T3 compared with T1 as a reference. Corresponding HRs (95% CI) in the elderly group (≥65 years) were 0.50 (0.40 to 0.62) and 0.41 (0.32 to 0.51), respectively. As regards the cause of death, higher levels of handgrip strength were significantly associated with decreased risks of cardiovascular death, respiratory death and death from other causes, but not of cancer, in the middle-aged and the elderly.

CONCLUSIONS

Our findings suggest that handgrip strength levels in midlife and late life are inversely associated with the risks of all-cause and non-cancer death in the general Japanese population.