Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults

Relationship between quadriceps femoris echotexture biomarkers and muscle strength and physical function in older adults with heart failure with preserved ejection fraction

BACKGROUND

Muscle wasting is pronounced in patients with heart failure with preserved ejection fraction (HFpEF). The quadriceps femoris echotexture biomarkers assessed by ultrasound (US) have not been studied in these patients.

OBJECTIVE

To describe echotexture biomarkers assessed by the US and to assess their relationship with sex, age, body mass index (BMI), self-reported outcomes, muscle strength and physical function in older adults with HFpEF.

METHODS

A cross-sectional study was conducted. Patients 70 years and older with HFpEF were included. The sex, age, BMI, and self-reported outcomes were collected. The US assessed muscle and subcutaneous fat tissue contrast, correlation, energy, homogeneity, and entropy at rest and maximal voluntary isometrical contraction (MVIC). The six-minute walk test (6MWT), the short physical performance battery (SPPB), the timed up and go test (TUG), the usual pace gait speed test (UGS), and the fast pace gait speed test (FGS) were used to assess physical function. The five-repetitions sit-to-stand test (5-STS) was performed to assess muscle strength. Bivariant Pearson correlations and subsequent multivariate linear regression analyses were conducted.

RESULTS

Seventy-two older adults with HFpEF [81.06 years, 29.13 BMI, and 55.60% females] were recruited. In women, relaxed and MVIC muscle energy and entropy explained 35.40% of the TUG variance; relaxed muscle entropy and MVIC muscle energy shared 24.00% of the UGS variance; relaxed and MVIC muscle entropy, MVIC muscle contrast and MVIC muscle energy explained 32.60% of the FGS variance, adjusted all the models by age and BMI.

CONCLUSIONS

Echotexture biomarkers are related to women's muscle strength and physical function, especially muscle energy, contrast, and entropy. Echotexture biomarkers assessed by the US could facilitate the management of older adults with HFpEF, monitor its progression and assess the effectiveness of treatments on the musculoskeletal structure.

TRIAL REGISTRATION

NCT03909919. April 10, 2019. Retrospectively registered.

Cognition as mediator of pulmonary function and risk of sarcopenia among older adults

BACKGROUND

The relationship between lung function and sarcopenia remains ambiguous. The primary aim of this study was to investigate the potential association between lung function and sarcopenia in the older adults, as well as to examine the mediating role of cognitive function in this relationship.

METHODS

The participants were selected from a nationally representative population-based cohort in China. The peak expiratory flow (PEF) measurement was used to evaluate the lung function in older persons. The sarcopenia was diagnosed using the guidelines of the Asian Working Group for Sarcopenia (AWGS) in 2019. The Cox proportional hazard model was utilized to perform primary analyses of the relationship between PEF and sarcopenia. The mediating effect of cognitive function was evaluated using the counterfactual mediation method.

RESULTS

This cohort study included 4,011 older adults (average age, 66.6 years; 53.3% males). During a follow-up period of 3.86 years, 349 individuals were diagnosed with sarcopenia. After adjusting for potential confounders, each one-standard-deviation increase in PEF was associated with a 28% reduction in the risk of sarcopenia (hazard ratio [HR]: 0.72; 95% confidence interval [CI]: 0.63, 0.80). There was a significant mediation of cognition for the association between PEF and incident sarcopenia, and the proportion mediated was 12.2% (95% CI: 4.5%, 23.1%).

CONCLUSIONS

Older adults with impaired lung function are more likely to develop sarcopenia. Nevertheless, cognition can explain only a small portion of this association. Thus, other potential pathways between lung function and sarcopenia must be elucidated.

Changes in real-world walking speed following 60-day bed-rest

The aim of this work was to explore whether real-world walking speed (RWS) would change as a consequence of 60-day bed-rest. The main hypothesis was that daily RWS would decrease after the bed-rest, with a subsequent recovery during the first days of re-ambulation. Moreover, an exploratory analysis was done in order to understand whether there is an agreement between the loss in RWS after bed-rest and the loss in the maximum oxygen uptake capacity (VO2max), or the loss in maximal vertical jump power (JUMP) respectively. Twenty-four subjects were randomly assigned to one of three groups: a continuous artificial gravity group, an intermittent artificial gravity group, or a control group. The fitted linear mixed effects model showed a significant decrease (p < 0.001) of RWS after the 60-day bed-rest and a subsequent increase (p < 0.001) of RWS during the 14-day recovery period in the study facility. No or little agreement was found between the loss in RWS and the loss in VO2max capacity or the loss in maximal vertical jumping power (RWS vs. VO2max: p = 0.81, RWS vs. JUMP: p = 0.173). Decreased RWS after bed-rest, with a follow-up recovery was observed for all three groups, regardless of the training intervention. This suggests that RWS, also in these settings, was able to reflect a de-conditioning and follow-up recovery process.

Resistance Training on an Outdoor Exercise Structure Improves Lower-Body Relative Strength in Older Adults

Improving relative strength is important for maintaining functionality with age, and outdoor exercise structures could be useful to facilitate this. A total of 29 adults aged 65+ participated in a non-randomized crossover study with a 6-week control followed by a 6-week resistance training intervention on an outdoor exercise structure (3x/week). Relative strength (predicted maximal leg press/lower body lean mass [Dual-energy X-ray Absorptiometry]) and physical function variables were measured at baseline, post-control, and post-intervention. Represented as median (25th-75th), lower body relative strength improved from 7.91 (7.01-9.35) post-control to 8.50 (7.99-9.72) post-intervention (p = .002) in study completers (n = 17). Maximum leg press (p = .002), 30-second chair stand (p < .001), one-leg stance (p = .011), and maximum chest press (p = .009) also improved significantly during the intervention. There were no significant changes in aerobic activity, grip strength, lean mass, or muscle power. This study demonstrates that there could be potential relative strength benefits associated with the use of outdoor exercise structures in older adults.

Blood flow restriction as a potential therapy to restore physical function following COVID-19 infection

Accumulating evidence indicates that some COVID-19 survivors display reduced muscle mass, muscle strength, and aerobic capacity, which contribute to impairments in physical function that can persist for months after the acute phase of illness. Accordingly, strategies to restore muscle mass, muscle strength, and aerobic capacity following infection are critical to mitigate the long-term consequences of COVID-19. Blood flow restriction (BFR), which involves the application of mechanical compression to the limbs, presents a promising therapy that could be utilized throughout different phases of COVID-19 illness. Specifically, we hypothesize that: 1) use of passive BFR modalities can mitigate losses of muscle mass and muscle strength that occur during acute infection and 2) exercise with BFR can serve as an effective alternative to high-intensity exercise without BFR for regaining muscle mass, muscle strength, and aerobic capacity during convalescence. The various applications of BFR may also serve as a targeted therapy to address the underlying pathophysiology of COVID-19 and provide benefits to the musculoskeletal system as well as other organ systems affected by the disease. Consequently, we present a theoretical framework with which BFR could be implemented throughout the progression from acute illness to outpatient rehabilitation with the goal of improving short- and long-term outcomes in COVID-19 survivors. We envision that this paper will encourage discussion and consideration among researchers and clinicians of the potential therapeutic benefits of BFR to treat not only COVID-19 but similar pathologies and cases of acute critical illness.

Dual-Task Performance, Balance and Aerobic Capacity as Predictors of Falls in Older Adults with Cardiovascular Disease: A Comparative Study

Cardiovascular diseases (CVD) are highly prevalent and strongly associated with the risk of falls in the elderly. Falls are associated with impairments in cognition and functional or gait performance; however, little is known about these associations in the elderly population with CVD. In this study, we aimed to clarify the possible associations of physical capacity and functional and cognitive outcomes with the incidence of falls in older adults with CVD. In this comparative study, 72 elderly patients were divided into fallers (n = 24 cases) and non-fallers (n = 48 controls) according to the occurrence of falls within one year. Machine learning techniques were adopted to formulate a classification model and identify the most important variables associated with the risk of falls. Participants with the worst cardiac health classification, older age, the worst cognitive and functional performance, balance and aerobic capacity were prevalent in the case group. The variables of most importance for the machine learning model were VO_2max, dual-task in seconds and the Berg Scale. There was a significant association between cognitive-motor performance and the incidence of falls. Dual-task performance, balance, and aerobic capacity levels were associated with an increased risk of falls, in older adults with CVD, during a year of observation.

The Clinical Phenotype of Binge Eating Disorder among Postmenopausal Women: A Pilot Study

Binge eating disorder (BED), a form of overnutrition, may impact healthy aging for postmenopausal women. In community samples, 12-26% of older women (ages 60+) engage in binge eating. In younger adults, BED is comorbid with physical and psychological morbidities. However, little is known regarding the clinical phenotype, including medical and psychiatric comorbidities, of BED in postmenopausal women. This pilot study sought to identify psychosomatic, cardiometabolic, body composition, and physical function characteristics of postmenopausal, older adult (age ≥60 years) women with BED. Participants (N = 21, ages 60-75) completed a battery of physical assessments and surveys assessing psychosomatic health. Overall, 62% of women reported BE onset during peri- or post-menopause. Rates of comorbid depression, anxiety, sleep problems, and a history of severe menopausal symptoms were high. Cardiometabolic health was poor, and 42.9% met the criteria for metabolic syndrome. Additionally, 71.4% met the BMI criteria for obesity, and 40% of this sample met the criteria for sarcopenic obesity. Almost half of the sample presented with at least one mobility limitation; 85.7% had poor endurance. Evidence suggests that BED is highly comorbid with other chronic health conditions and may complicate treatment of these conditions, warranting further investigation and increased attention from healthcare providers serving postmenopausal women.

Muscle quality index is associated with trouble sleeping: a cross-sectional population based study

BACKGROUND

Trouble sleeping is one of the major health issues nowadays. Current evidence on the correlation between muscle quality and trouble sleeping is limited.

METHODS

A cross-sectional study design was applied and participants aged from 18 to 60 years in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 was used for analysis. Muscle quality index (MQI) was quantitatively calculated as handgrip strength (HGS, kg) sum/ arm and appendicular skeletal muscle mass (ASM, kg) by using the sum of the non-dominant hand and dominant hand. Sleeping data was obtained by interviews and self-reported by individuals. The main analyses utilized weighted multivariable logistic regression models according to the complex multi-stage sampling design of NHANES. Restricted cubic spline model was applied to explore the non-linear relationship between MQI and trouble sleeping. Moreover, subgroup analyses concerning sociodemographic and lifestyle factors were conducted in this study.

RESULTS

5143 participants were finally included in. In the fully adjusted model, an increased level of MQI was significantly associated with a lower odds ratio of trouble sleeping, with OR = 0.765, 95% CI: (0.652,0.896), p = 0.011. Restricted cubic spline showed a non-linear association between MQI and trouble sleeping. However, it seemed that the prevalence of trouble sleeping decreased with increasing MQI until it reached 2.362, after which the odds ratio of trouble sleeping reached a plateau. Subgroup analyses further confirmed that the negative association between the MQI and trouble sleeping was consistent and robust across groups.

CONCLUSION

Overall, this study revealed that MQI can be used as a reliable predictor in odds ratio of trouble sleeping. Maintaining a certain level of muscle mass would be beneficial to sleep health. However, this was a cross-sectional study, and causal inference between MQI and trouble sleeping was worthy of further exploration.

Field-Based Estimates of Muscle Quality Index Determine Timed-Up-and-Go Test Performance in Obese Older Women

Objective

The muscle quality index (MQI) is associated with numerous health outcomes in adults; however, the effects of distinct MQI on functional capacity in obese older women have not yet been fully investigated. Thus, we investigated the contribution of different muscle quality indices on TUG performance prediction in obese older women. We secondarily evaluated the association between MQI, aerobic capacity performance (Treadmill performance and 6-minute walk test), and obesity indices (BMI, body fat percentage, and neck, waist, and hip circumference).

Methods

Participants included 64 obese older women (mean age 67.05 ± 5.46 years, body fat ≥ 35%). General anthropometric, health history, body composition, treadmill exercise, and functional test (Time up and go) measures were collected. A hydraulic dynamometer was used to assess muscle strength, and Dual Energy X-ray Absorptiometry (DXA) to identify body fat percentage. The field MQI was defined as the highest reading divided by the subject's body mass index (BMI), while the laboratory MQI was obtained by the ratio of grip strength to the entire arm muscle in kilograms measured by DXA. A hierarchical multiple regression was performed to predict TUG-test performance.

Results

An increase in field MQI of one unit is associated with a decrease of 2.59 seconds in the TUG test (β = -0.540; p = 0.004). There was no association between laboratory MQI and TUG performance (β = 0.067; p = 0.712). Furthermore, field MQI displays a positive correlation (p < 0.05) with aerobic capacity performance (6-minute walk test and peak O₂ consumption) and a negative correlation (p < 0.05) with diverse obesity indices (neck and waist circumference, body fat, and BMI).

Conclusion

MQI displayed an important prediction with TUG-test, a positive correlation with aerobic capacity, and a negative correlation with obesity indices.

Relationship between quadriceps femoris muscle architecture and muscle strength and physical function in older adults with heart failure with preserved ejection fraction

Heart failure (HF)-related factors potentially lead to sarcopenia. Ultrasound (US) assessment has all the advantages of being used in clinical practice to assess muscle architecture. This study aimed to assess the relationship between the quadriceps femoris (QF) muscle architecture with the gender, age, body mass index (BMI), muscle strength and physical function in older adults with HF with preserved ejection fraction (HFpEF) as well as to assess the difference in these relationships between the two genders. Patients 70 years and older with HFpEF were included. The gender, age and BMI were collected. The QF muscle thickness, the QF muscle echo-intensity, the subcutaneous fat tissue thickness (FT) and the subcutaneous fat tissue echo-intensity were assessed by the US. The six-minute walk test, the short physical performance battery (SPPB), the timed up and go test (TUG), and the gait speed test (UGS) were used to assess physical function. The five-repetitions sit-to-stand test (5-STS) was performed to assess muscle strength. Bivariant Pearson correlations and subsequent multivariate linear regression analysis were conducted. Seventy older adults with HFpEF [81.00 (5.97) years] were recruited. The FT showed a correlation between poor and moderate muscle strength and physical function in women with HFpEF. The FT explained 24.5% of the 5-STS variance, 32.4% of the SPPB variance, 31.5% of the TUG variance, 28.6% of the UGS variance, and 21.4% of the FGS variance in women. The US assessment could allow clinicians to assess muscle architecture biomarkers related to muscle strength and physical function in older adults with HFpEF.Trial registration NCT03909919. April 10, 2019. Retrospectively registered.

Lower limb muscle quality and phase angle contribute to the reduced walking speed among older adults

AIM

This cross-sectional study aimed to determine the predictors of a walking speed <1 m/s. Factors associated with the health of muscle cells, including the phase angle analyzed using bioimpedance analysis, answers to the mini-nutritional assessment-short form, albumin levels, leg muscle quality and vitamin D levels, were assessed.

METHODS

The study participants were outpatients from the Locomotor Frailty Outpatient Clinic which was established at our center in 2016 (231 women, 76.5 ± 7.6 years; 137 men, 78.0 ± 6.3 years). Participants were classified into two groups, with 1 m/s walking speed as the cutoff value. Binominal logistic regression analysis was performed with walking speed as the dependent variable, and age, leg muscle quality, mini-nutritional assessment-short form answers, albumin levels, vitamin D levels and the phase angle as explanatory variables. Leg muscle quality was defined as the mean value of both lower limbs' isometric knee extensor strength, divided by the mean value of both lower limbs' muscle mass through bioimpedance analysis.

RESULTS

The explanatory variables associated with decreased walking speed among women were leg muscle quality (P = 0.004, odds ratio: 0.57) and phase angle (P = 0.017, odds ratio: 0.42). Men were also more likely to have leg muscle quality (P = 0.004, odds ratio: 0.43).

CONCLUSIONS

Leg muscle quality and the phase angle of lower extremities were independently associated with low walking speeds (<1 m/s) among older outpatients. Geriatr Gerontol Int 2022; ••: ••-••.

Effect of Dietary Weight Loss and Macronutrient Intake on Body Composition and Physical Function in Adults with Knee Osteoarthritis: A Systematic Review

Overweight and obesity increase the risk of development and progression of knee osteoarthritis (OA), with higher levels of fat mass and lower levels of lean mass associated with poorer functional status. The aim was to assess changes in weight, body composition and physical function following weight loss or weight maintenance interventions in knee OA. A comprehensive search of four databases was conducted. The risk of bias was assessed using the Quality Criteria Checklist for primary research. Primary outcomes included weight, body composition and physical function; secondary outcomes were lipids, inflammatory biomarkers and muscle strength. Eleven studies were included utilizing diet and exercise (n = 4) or diet-only (n = 7) interventions, two of which were weight maintenance studies. Most studies (n = 10) reported improvements in physical function with significant weight loss, while the change in strength reported in three studies was variable. The diet and exercise studies reported an average reduction in weight of 6.7% and lean mass of 1.6 kg, with greater improvements in physical function. The diet-only studies, including weight maintenance interventions, reported greater average weight loss (7.8%) and reduction in LM (2.0 kg). Overall, better retention of lean mass and muscle strength was observed in participants with higher protein intake (≥37% of energy) and subsequently improved physical function.

Low hand grip strength is associated with worse functional capacity and higher inflammation in people receiving maintenance hemodialysis

OBJECTIVES

To evaluate the associations of hand grip strength (HGS) with body composition, functional capacity, muscle quality, and inflammatory markers in people receiving maintenance hemodialysis.

METHODS

This is a cross-sectional study in people receiving maintenance hemodialysis. HGS was measured by hydraulic dynamometer on the upper limb without fistula. Participants were stratified into low or adequate HGS, based on population-specific cutoff points. Body composition was assessed by dual-energy X-ray absorptiometry, and functional capacity by the Short Physical Performance Battery and timed up-and-go tests. In addition, serum creatinine, interleukin-6 (IL-6), IL-10, tumor necrosis factor-α, and ultra-sensitive C-reactive protein (us-CRP) were measured before the dialysis session.

RESULTS

A total of 67 participants (41.8% women, 58.2% male; ages 54.1 ± 11.7 y) were included. Those with low HGS had worse functional capacity than those with adequate HGS (timed up-and-go test, 10.7 ± 1.0 versus 8.5 ± 0.8 sec, respectively; P < 0.001). IL-6 and us-CRP were higher in those with low HGS than their counterparts (IL-6: 2.7 ± 0.3 versus 1.9 pg/mL, P = 0.03; us-CRP: 14.8 ± 3.0 versus 4.7 ± 1.9 mg/L, P = 0.03). Multiple linear regression analysis showed that appendicular lean mass, us-CRP, age, sex, and seven-point subjective global assessment score were associated with HGS.

CONCLUSIONS

Participants with low HGS showed higher inflammation and lower functional capacity. In addition to muscle mass, inflammation and nutritional status also affect HGS.<END ABSTRACT>.

Relation of Physical Activity Level to Postural Balance in Obese and Overweight Spanish Adult Males: A Cross-Sectional Study

The aim of this study was to analyze the influence of physical activity level on postural control in obese and overweight Spanish adult males. Forty-three males aged between 25 and 60 years old were included. Anthropometric, body composition, and physical activity variables were assessed, and postural control was evaluated using the Sensory Organization Test. No correlation was found between the level of physical activity and postural control, assessed by the Sensory Organization Test within the whole sample. However, within the group with a higher total fat mass percentage, non-sedentary individuals presented improved scores on the somatosensory organization test when compared to sedentary individuals (96.9 ± 1.8 vs. 95.4 ± 1.2; p < 0.05) and poorer scores on the composite equilibrium score (73.4 ± 7.2 vs. 79.2 ± 6.9; p < 0.05). The altered integration of somatosensory inputs most likely affects the tuning, sequencing, and execution of balance strategies in sedentary men with a high total fat mass percentage.

Impact of Sarcopenia on Degenerative Lumbar Spondylosis

Sarcopenia is characterized by progressive age-related and systematic loss of skeletal muscle mass, strength, and function. It was classified as an independent disease in 2016; thus, there is a sparsity of research on the association of sarcopenia with lower back pain and spinal diseases. Its prevalence is around 10% worldwide and it has been shown to be detrimental to quality of life in the elderly. Sarcopenia can be clinically identified by assessing muscle mass and physical performance measurements to show reduced strength (eg, grip strength chair rise and knee extensions) or function (eg, walking speed or distance). Radiographic imaging techniques such as computed tomography, ultrasound, or magnetic resonance imaging help diagnose sarcopenia in the lumbar spine by measuring either the cross-sectional area or the fatty infiltrate of the lumbar musculature. The presence of sarcopenia in patients preoperatively may lead to worse postoperative outcomes. Research in the treatment options for sarcopenia presurgery is still in its infancy but exercise (both aerobic and resistance exercise have been found to slow down the rate of decline in muscle mass and strength with aging) and nutrition have been utilized to varying success and show great promise in the future.

Daily Supplementation With Whey, Soy, or Whey-Soy Blended Protein for 6 Months Maintained Lean Muscle Mass and Physical Performance in Older Adults With Low Lean Mass

BACKGROUND

Few studies have investigated the effect of long-term protein supplementation alone on muscle health in older adults with low lean mass.

OBJECTIVE

To determine the effect of whey, soy or whey-soy blended protein supplementation on lean muscle mass and physical performance in older adults with low lean mass.

DESIGN

A 4-arm randomized controlled trial.

PARTICIPANTS/SETTING

Chinese older adults (n = 123, 65-79 years) with low lean mass (appendicular skeletal muscle index < 7.0 kg/m² in men and < 5.4 kg/m² in women) living in the urban area of Guangzhou participated between October 2015 and June 2016.

INTERVENTION

Participants were randomly assigned to receive approximately 16 g/d of whey, soy, or whey-soy blend protein or maintained habitual diets in control group for 6 months.

MAIN OUTCOME MEASURES

Lean mass, handgrip strength, and physical performance (gait speed, chair stand test, and Short Physical Performance Battery) were assessed at baseline and 6 months.

STATISTICAL ANALYSES

Two-way analysis of variance with the main effects of treatment and time and treatment × time interaction and analysis of covariance was used to determine differences in outcomes.

RESULTS

Appendicular skeletal muscle index, lean mass, percent lean mass in legs and appendicular areas, gait speed, and Short Physical Performance Battery score were maintained in the treatment groups and decreased in the control group, resulting in significant reduction in these variables from baseline in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 80% to 156%). The chair stand test time at month 6 decreased from baseline in the treatment groups and increased in the control group, resulting in a significant increase in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 132% to 155%). Handgrip strength remained unchanged. There were no significant differences in outcomes among treatment groups.

CONCLUSIONS

Supplementation with whey, soy, or whey-soy blended protein for 6 months equally maintained lean muscle mass and physical performance in older adults with low lean mass.

Poor Walking Speed Is Associated With Higher Segment-Specific Arterial Stiffness in Older Adult Japanese Community Dwellers: A Cross-Sectional Study

Walking speed as one index of gait ability is an important component of physical fitness among older adults. Walking speed-arterial stiffness relationships have been studied, but whether poor walking speed is associated with higher segment-specific arterial stiffness in older adults is unclear. We thus aimed to examine the relationship between walking speed and segmental arterial stiffness among older community dwellers. This study was a cross-sectional study of 492 older Japanese community dwellers (age range, 65 to 96 years). Heart-brachial PWV (hbPWV), brachial-ankle PWV (baPWV), heart-ankle PWV (haPWV), and cardio-ankle vascular index (CAVI) were used as arterial stiffness indices. Walking speed, strength, flexibility, and cognitive function were also assessed. The participants were categorized into low (Slow), middle (Middle), and high (Fast) tertiles according to walking speed. The CAVI and baPWV were significantly lower in Fast than in Slow. Significant decreasing trends in CAVI and baPWV and a tendency toward decreasing trend in haPWV were observed from Slow to Fast, whereas hbPWV did not significantly differ among tertiles and no trend was evident. The results remained significant after normalizing CAVI and PWVs for multicollinearity of arterial stiffness indices and major confounding factors, such as age, gender, body mass index, blood pressure, cognitive function, and each physical fitness. Therefore, these findings suggest that poor walking speed is associated with higher segment-specific arterial stiffness of the central and lower limbs, but not of upper, in older adult community dwellers.

Intensity of resistance training via self-reported history is critical in properly characterizing musculoskeletal health

BACKGROUND

Intensity of resistance training history might be omitted or poorly ascertained in prescreening or data questionnaires involving musculoskeletal health. Failure to identify history of high-versus low-intensity training may overlook higher effect sizes with higher intensities and therefore diminish the precision of statistical analysis with resistance training as a covariate and bias the confirmation of baseline homogeneity for experimental group designation. The purpose was to determine the degree to which a single question assessing participant history of resistance training intensity predicted differences in musculoskeletal health.

METHODS

In the first research aim, participants were separated into groups with a history (RT) and no history (NRT) of resistance training. The second research aim evaluated the history of resistance training intensity on muscular strength, lean mass, and bone mineral density (BMD), RT participants were reassigned into a low- (LIRT) or high-intensity resistance training group (HIRT). 83 males and 87 females (19.3 ± 0.6 yrs., 171.1 ± 9.9 cm, 67.1 ± 10.5 kg, 22.9 ± 2.8 BMI, 26.2 ± 7.2% body fat) completed handgrip dynamometry (HG) and dual-energy x-ray absorptiometry scans (DXA) for BMD and bone mineral-free lean mass (BFLM).

RESULTS

A 3-group method (NRT, LIRT, HIRT) reduced type-I error compared with the 2-group method (NRT, RT) in characterizing the likely effects of one's history of resistance training. For the second aim, HIRT had significantly (p < 0.05) greater HG strength (76.2 ± 2.2 kg) and arm BFLM (6.10 ± 0.16 kg) than NRT (67.5 ± 1.3 kg; 4.96 ± 0.09 kg) and LIRT (69.7 ± 2.0 kg; 5.42 ± 0.14 kg) while also showing significantly lower muscle quality (HG/BFLM) than NRT (13.9 ± 0.2 vs. 12.9 ± 0.3). HIRT had greater BMD at all sites compared to NRT (whole body = 1.068 ± 0.008 vs. 1.120 ± 0.014; AP spine = 1.013 ± 0.011 vs. 1.059 ± 0.019; lateral spine = 0.785 ± 0.009 vs. 0.846 ± 0.016; femoral neck = 0.915 ± 0.013 vs. 0.970 ± 0.022; total hip = 1.016 ± 0.012 vs. 1.068 ± 0.021 g/cm2) while LIRT revealed no significant skeletal differences to NRT.

CONCLUSIONS

Retrospective identification of high-intensity history of resistance training appears critical in characterizing musculoskeletal health and can be ascertained easily in as little as a single, standalone question. Both retrospective-questionnaire style investigations and pre-screening for potential participation in prospective research studies should include participant history of resistance training intensity.

COVID-19 pandemic is an urgent time for older people to practice resistance exercise at home

Social distancing measures have been used to contain the COVID-19 pandemic; nevertheless, it causes unintended greater time at home and consequently a reduction in general physical activity and an increase in sedentary time, which is harmful to older people. A decrease in daily physical activities and an increase in sedentary time culminates in an impactful skeletal muscle disuse period and reduction in neuromuscular abilities related to functional capacity. Home-based resistance training is a strategy to mitigate physical inactivity and improve or retain muscle function and functional performance. Therefore, it is an urgent time to encourage older people to perform resistance exercises at home to avoid a harmful functional decline and promote physical health.

Lean, fast and strong: Determinants of functional performance in the elderly

BACKGROUND

The current literature indicates that functional capacity is associated with physical performance and body composition measurements in older adults. However, it is not clear which tests can best explain the functional capacity in this population. This study aimed to investigate the physical performance and body composition determinants of functional capacity in older adults.

METHOD

Twenty-four older adults (66.4 ± 4.7y) undertook body composition (body fat and muscle), rate of torque development (0-50 and 0-200 ms); countermovement jump (height, power and impulse); leg-press and seated-leg-curl 5-repetition maximum; and functional-performance tests (Timed-up-and-go, stair ascent and stair descent).

FINDINGS

Timed-up-and-go correlated with countermovement jump (height, R² = 0.303; power, R² = 0.198; and impulse, R² = 0.224) and 5-repetition maximum (seated-leg-curl, R² = 0.172). Stair ascent correlated with body fat (R² = 0.213), rate of torque development (0-50 ms/body fat, R² = 0.301; 0-200 ms_, R² = 0.197; 0-200 ms/body fat, R² = 0.340), countermovement jump (height, R² = 0.325; power/body fat, R² = 0.413; impulse/body fat, R² = 0.422) and 5-repetiton maximum (leg-press/body fat, R² = 0.384; seated-leg-curl/body fat, R² = 0.341). Stair descent correlated with rate of torque development (0-50 ms/body fat, R² = 0.164; 0-200 ms, R² = 0.203; 0-200 ms/body fat, R² = 0.213), countermovement jump (height, R² = 0.458; power, R² = 0.212; power/body fat, R² = 0.358; impulse, R² = 0.218; impulse/body fat, R² = 0.369) and 5-repetition maximum (leg-press/body fat, R² = -0.227; seated-leg-curl/body fat, R² = 0.209; seated-leg-curl, R² = 0.181).

INTERPRETATION

Higher body fat is associated with weaker stair ascent performance. An increase in the correlation coefficient was observed for the countermovement jump, rate of torque development, and 5-repetition maximum tests when normalized by body fat compared to the absolute values. Countermovement jump height presented the highest correlation to timed-up-and-go and stair descent, while impulse/body fat for stair ascent.

Effects of 12-week resistance exercise and interval training on the skeletal muscle area, physical fitness, and mental health in old women

This study aimed to determine the effects of resistance exercise and interval training on the visceral fat to skeletal muscle area, physical fitness, cognitive functions, and mental health in old women. The study was conducted among 30 older women enrolled in the National Fitness Center in Seoul. They were randomly sampled into the resistance exercise and interval training group (RI group: n=10, aged 64.10±3.35), the resistance and aerobic exercise group (RA group: n=10, aged 65.20± 5.10), and the control group (n=10, aged 63.20±2.62). Twelve weeks of exercise involving 30-min resistance exercise followed by 30-min interval training or aerobic exercise, 3 times a week, were performed by each group. A computed topography was used to the measure visceral fat area and the thigh skeletal muscle area. For physical fitness, maximum oxygen uptake, knee isokinetics muscle functions, ankle range of motion, and functional fitness of the elderly (muscle strength, cardiorespiratory endurance, flexibility, balance, and agility) were measured. For blood test, the metabolic syndrome risk factors, growth hormone, testosterone, and insulin-like growth factor-1 (IGF-1) were measured. A self-administered questionnaire was used to measure cognitive functions and quality of sleep. The 12-week RA and RI groups were effective in changing the thigh skeletal muscle area, IGF-1, knee joint extension and flexion, ankle range of motion, functional fitness, and quality of sleep. In conclusion, resistance exercise, followed by interval training or aerobic exercise, was effective in improving the skeletal muscle function indexes, physical fitness, and quality of sleep for the elderly. However, no difference was found between the two types of exercise.

The effects of same-session combined exercise training on cardiorespiratory and functional fitness in older adults: a systematic review and meta-analysis

Endurance and strength training are effective strategies for counteracting age-associated reductions in physical performance in older adults, with a combination of both exercise modes recommended to maximise potential fitness benefits. This meta-analysis sought to quantify the effects of same-session combined endurance and strength training on fitness in adults aged over 50 years. Five electronic databases were searched with studies required to include one of the following outcome measures: VO_2peak, 6-min walk test (6MWT), 8-ft timed up-and-go (TUG), and 30-s chair stand. Separate random-effects meta-analyses compared combined training with (1) no-exercise control, (2) endurance training, and (3) strength training with probabilistic magnitude-based inferences subsequently applied. Twenty-seven studies involving 1346 subjects with a mean age of 68.8 years (range 54–85 years) were included in the analysis. The meta-analysed effect on VO_2peak was a moderately beneficial effect for the combined training compared to no-exercise controls (3.6 mL kg⁻¹ min⁻¹; ± 95% confidence limits 0.8 mL kg⁻¹ min⁻¹) with additional increases for studies with greater proportions of female participants and shorter training interventions. Combined training also had small-to-moderately beneficial effects on VO_2peak when compared to endurance training (0.8 mL kg⁻¹ min⁻¹; ± 1.0 mL kg⁻¹ min⁻¹), 30-s chair stand when compared with strength training (1.1 repetitions; ± 0.5 repetitions) and on TUG (0.8 s; ± 0.7 s), 30-s chair stand (2.8 repetitions; ± 1.7 repetitions), and 6MWT (31.5 m; ± 22.4 m) when compared to no-exercise controls. All other comparisons were unclear. Same-session combined training can induce clinically relevant fitness improvements in older adults.

Relevance to assess and preserve muscle strength in aging field

According to the revised European consensus on sarcopenia, muscle strength is the primary parameter of sarcopenia and is associated with adverse outcomes or physical limitation. This literature review aims to clarify how and why to measure and preserve muscle strength in older population. Overall, the relationship between muscle strength and physical function is impacted by level of muscle mass, the degree of obesity (BMI), age and physical activity. Therefore, these factors are to be considered in the evaluation of muscle strength. It is necessary to have objective, reliable and sensitive tools to assess muscle strength, in different populations to detect and quantify weakness, to adapt physical exercises to patients' capacity and to evaluate the effects of treatment. Handgrip strength measurement might be reasonable for clinical practice while the measurement of knee flexors/extensors strength with both 1RM and dynamometers is increasingly important yet restricted by the requirement of special equipment. Physical activity and nutrition are two important behavioral factors to maintain muscle strength. Combined exercise and nutrition interventions improved muscle strength to a more prominent degree than exercise or nutrition alone.

Effectiveness of a muticomponent workout program integrated in an evidence based multimodal program in hyperfrail elderly patients: POWERAGING randomized clinical trial protocol

BACKGROUND

Short-term and mid-term comparison of the efficacy of a multimodal program that incorporates a therapeutic workout program, medication review, diet adjustment and health education, in comparison to the standard medical practice in the improvement of the neuromuscular and physiological condition. Furthermore, it is intended to analyse the maintenance of these effects in a long-term follow-up (12 months) from the onset of the intervention.

METHODS

A randomized clinical trial of elderly frail patients drawn from the Clinical Management Unit "Tiro de Pichón", Health District of Malaga, will be included in the study (after meeting the inclusion / exclusion criteria) will be randomized in two groups: a control group that will undergo an intervention consistent of medication review + diet adjustment + health education (regular workout recommendations within a complete advice on healthy lifestyles) and an experimental group whose intervention will consist of a multimodal treatment: therapeutic workout program+ medication review+ diet adjustment + health education. The sociodemographic, clinical and tracing variables will be reflected at the beginning of the study. In addition, the follow-up variables will be gathered at the second and sixth months after the beginning of the treatment and at the third and sixth months after the treatment (follow-up). The follow-up variables that will be measured are: body mass index, general health condition, fatigue, frailty, motor control, attention- concentration- memory, motor memory, spatial orientation, grip strength, balance (static, semi-dynamic), gait speed and metabolomics. A descriptive analysis of the sociodemographic variables of the participants will be conducted. One-Factor ANOVA will be used for the Within-Subject analysis and as for the Between-Subject analysis, the outcome variables between both the groups in each moment of the data collection will be compared.

DISCUSSION

A multimodal program that incorporates a therapeutic workout program, medication review, diet adjustment and health education may be effective treatment to reduce the functional decline in elderly. The results of the study will provide information on the possible strengths and benefits in multimodal program in elderly.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02772952 registered May 2017.

The Role of Ultrasound as a Diagnostic Tool for Sarcopenia

Sarcopenia is the progressive loss of skeletal mass and strength, particularly in older adults, with consequent reduction in function and independence. Changing population demographics, have resulted in increased prevalence of sarcopenia and this is associated with a considerable economic burden. Whilst simple, effective, non-intrusive management of this condition exists, no routine diagnosis takes place either in the UK or in many other countries, partly due to an absence of pragmatic clinical diagnostic tools to support the early identification of the syndrome. This position paper aims to provide a short overview proposing the potential case for developing ultrasound as a new and alternative diagnostic tool for identifying sarcopenia.

A Scoping Review of Epidemiological, Ergonomic, and Longitudinal Cohort Studies Examining the Links between Stair and Bathroom Falls and the Built Environment

Stair and bathroom falls contribute to injuries among older adults. This review examined which features of stairs and bathrooms have been assessed in epidemiological, ergonomic, and national aging studies on falls or their risk factors. Epidemiological and ergonomic studies were eligible if published from 2006-2017, written in English, included older persons, and reported built environment measures. The data extracted included the following: study population and design, outcome measures, and stair and bathroom features. National aging studies were eligible if English questionnaires were available, and if data were collected within the last 10 years. Sample characteristics; data collection methods; and data about falls, the environment, and assistive device use were extracted. There were 114 eligible articles assessed-38 epidemiologic and 76 ergonomic. Among epidemiological studies, 2 assessed stair falls only, 4 assessed bathroom falls only, and 32 assessed falls in both locations. Among ergonomic studies, 67 simulated stairs and 9 simulated bathrooms. Specific environmental features were described in 14 (36.8%) epidemiological studies and 73 (96%) ergonomic studies. Thirteen national aging studies were identified-four had stair data and six had bathroom data. Most epidemiologic and national aging studies did not include specific measures of stairs or bathrooms; the built environment descriptions in ergonomic studies were more detailed. More consistent and detailed environmental measures in epidemiologic and national aging studies would better inform fall prevention approaches targeting the built environment.

Impact of exercise training on physical and cognitive function among older adults: a systematic review and meta-analysis

Exercise plays a key role in healthy aging by promoting both physical and cognitive function. Physical function and cognitive function appear to be interrelated and may share common mechanisms. Thus, exercise-induced improvements in physical function and cognitive function may co-occur and be associated with each other. However, no systematic review has specifically assessed and compared the effects of exercise on both physical function and cognitive function in older adults, and the association between changes in both outcomes after exercise training. Thus, we conducted a systematic review and meta-analysis (N = 48 studies) among older adults (60+ years). These data suggest exercise training has a significant benefit for both physical function (g = 0.39; p < 0.001) and cognitive function (g = 0.24; p < 0.001). At the study level, there was a positive correlation between the size of the exercise-induced effect on physical function and on cognitive function (b = 0.41; p = 0.002). Our results indicate exercise improves both physical and cognitive function, reiterating the notion that exercise is a panacea for aging well.

Reduced body weight or increased muscle quality: Which is more important for improving physical function following exercise and weight loss in overweight and obese older women?

The purpose of this study was to examine the relative contributions of changes in muscle quality and body composition to changes in lower-extremity physical function (LEPF) following a 6-month exercise and weight loss intervention in overweight and obese older women. Thirty-eight overweight and obese (BMI = 30.0 ± 4.4 kg/m²) older (age = 69.3 ± 4.1 y) women completed 6 months of multicomponent exercise (cardiorespiratory, resistance, balance and flexibility training) and weight loss (hypocaloric diet that reduced energy intake by ~500 kcal/d). Body composition was measured via dual-energy X-ray absorptiometry and muscle quality (N-m/kg) was defined as maximal concentric isokinetic knee torque divided by upper-leg lean mass. The standardized scores of four objective measures of physical function were summed to yield a composite LEPF Z-score. At 6 months, there were significant reductions in body weight (-9.6 ± 3.5%, p < 0.01), absolute fat mass (-6.8 ± 2.4 kg, p < 0.01) and relative adiposity (-4.9 ± 2.1%, p < 0.01). There were also improvements in both muscle quality (+1.6 ± 1.8 N-m/kg, p < 0.01) and individual measures of LEPF (11-57%, p < 0.01). Multivariate linear regression indicated that increased muscle quality was the strongest independent predictor of an improvement in LEPF Z-score (standardized β = 0.64, p < 0.01) and explained 34% of the variance. A reduction in body weight also predicted an improvement in LEPF, independent of the change in muscle quality. In conclusion, muscle quality can be increased in the presence of clinically meaningful weight loss, and is the primary determinant of improved physical function in overweight/obese older women.

Influence of menopausal status on the main contributors of muscle quality

BACKGROUND

Muscle quality is a strong independent predictor of physical function. Body mass and fatness, muscle mass and cardiorespiratory fitness are known to influence muscle quality.

OBJECTIVE

To identify the contributors of muscle quality in young and postmenopausal women and whether hormone replacement therapy (HT) could influence this relationship at the age of menopause.

METHODS

Fifty-four postmenopausal women, 27 not on HT (PMW) and 27 on HT (PMW-HT), and 33 young women (YW) were evaluated for (1) body composition (body mass index, BMI), total fat mass (FM, %), appendicular lean mass (ALM, in kg and %), and appendicular skeletal mass index (ASMI = ALM/height² in kg/m²); (2) absolute peak oxygen uptake (VO_2peak, in ml/min) and relative peak oxygen uptake (VO_2peakRel in ml/kg/min); and (3) absolute isometric knee extension strength (iKES in kg) and relative isometric knee extension strength (iKES/BMI and iKES/ALM).

RESULTS

YW, PMW and PMW-HT had similar BMI (32.1 ± 10.2, 27.3 ± 4.7 and 26.7 ± 4 kg/m²) and FM (39.8 ± 10.0, 39.8 ± 7.3 and 39.9 ± 7.1%), respectively. Correlations were found between iKES/BMI index and FM (r = -0.52), ALM (r = 0.32) and VO_2peak (r = 0.31). Regression analysis demonstrated that, in YW, total amount of variance in iKES/BMI was mostly explained by ALM (42%), whereas, in PMW and PMW-HT, it was cumulatively explained by FM along with VO_2peakRel (34 and 46%, respectively).

CONCLUSION

The main contributors of muscle quality differ between young and postmenopausal women and HT does not seem to influence this relationship.

Effects of Different Concurrent Resistance and Aerobic Training Frequencies on Muscle Power and Muscle Quality in Trained Elderly Men: A Randomized Clinical Trial

Muscle power is a strong predictor of functional status in the elderly population and is required to perform different daily activities. To compare the effects of different weekly training frequencies on muscle power and muscle quality induced by concurrent training (resistance + aerobic) in previously trained elderly men. Twenty-four trained elderly men (65 ± 4 years), previously engaged in a regular concurrent training program, three times per week, for the previous five months, were randomly allocated to concurrent training programs in which training was performed either twice a week (2·week^-1, n = 12) or three times per week (3·week^-1, n = 12). The groups trained with an identical exercise intensity and volume per session for 10 weeks. Before and after the exercise training, we examined muscle power, as estimated by countermovement jump height; knee extensor isokinetic peak torque at 60 and 180^o.s^-1; and muscle quality, a quotient between the one-repetition maximum of the knee extensors and the sum of quadriceps femoris muscle thickness determined by ultrasonography. Additionally, as secondary outcomes, blood pressure and reactive hyperemia were evaluated. Two-way ANOVA with repeated measures were used and statistical significance was set at α = 0.05. Muscular power (2·week^-1: 7%, and 3·week^-1: 10%) and muscle quality (2·week^-1: 15%, and 3·week^-1: 8%) improved with the concurrent exercise training (p < 0.001) but with no differences between groups. The isokinetic peak torque at 60 (2·week^-1: 4%, and 3·week^-1: 2%) and 180^o.s^-1 (2·week^-1: 7%, and 3·week^-1: 1%) increased in both groups (p = 0.036 and p=0.014, respectively). There were no changes in blood pressure or reactive hyperemia with the concurrent training. Concurrent training performed twice a week promotes similar adaptations in muscular power and muscle quality when compared with the same program performed three times per week in previously trained elderly men.

The role of continuous versus fractionated physical training on muscle oxidative stress parameters and calcium-handling proteins in aged rats

Age-associated decline in skeletal muscle mass and strength is associated with oxidative stress and Ca(2+) homeostasis disturbance. Exercise should be considered a viable modality to combat aging of skeletal muscle. This study aimed to investigate whether continuous and fractionated training could be useful tools to attenuate oxidative damage and retain calcium-handling proteins. We conducted the study using 24-month-old male Wistar rats, divided into control, continuous, and fractionated groups. Animals ran at 13 m min(-1) for five consecutive days (except weekends) for 6 weeks, for a total period of 42 days. Each session comprised 45 min of exercise, either continuous or divided into three daily sessions of 15 min each. Metabolic and oxidative stress markers, protein levels of mitochondrial transcription factors, and calcium-handling proteins were analyzed. Continuous exercise resulted in reduced ROS production as well as showed a decrease in TBARS levels and carbonyl content. On the other hand, fractionated training increased the antioxidant enzyme activities. The ryanodine receptor and phospholamban protein were regulated by continuous training while sodium calcium exchange protein was increased by the fractionated training. These data suggest that intracellular Ca(2+) can be modulated by various training stimuli. In addition, the modulation of oxidative stress by continuous and fractionated training may play an important regulatory role in the muscular contraction mechanism of aged rats, due to changes in calcium metabolism.

The muscle quality index and mortality among males and females

PURPOSE

The muscle quality index (MQI) was proposed as a measure to quantify age-related alterations in muscle function. It is unknown if the MQI predicts mortality.

METHODS

This was a population-based cohort study from the Third National Health and Nutrition Survey (NHANES III; 1988-1994). The MQI was quantified using a timed sit-to-stand test, body mass, and leg length. Vital status was obtained through the National Center for Health Statistics. We fit multivariable-adjusted regression models to estimate the hazard ratio (HR) and 95% confidence interval (CI) between the MQI and mortality.

RESULTS

During 14.6 years of follow-up, 3299 (73.1%) of 4510 study participants died. Lower MQI was associated with a higher risk of mortality (Ptrend <.001). The multivariable-adjusted HR for mortality was 1.50 (95% CI, 1.15-1.96) for those in the lowest quintile of MQI compared to the highest quintile. The association between MQI and mortality was stronger among males (highest vs. lowest quintile of MQI, HR = 1.37 [95% CI, 1.00-1.87]; Ptrend = .001) compared to females (highest vs. lowest quintile of MQI, HR = 1.27 (95% CI, 0.89-1.83); Ptrend = .044; Pinteraction = .005].

CONCLUSIONS

The MQI predicts mortality and may differ between males and females. Additional research examining the MQI is warranted.

Associations between daily physical activity, handgrip strength, muscle mass, physical performance and quality of life in prefrail and frail community-dwelling older adults

Purpose

The aim of this study was to examine the associations between daily physical activity (DPA), handgrip strength, appendicular skeletal muscle mass (ASMM) and physical performance (balance, gait speed, chair stands) with quality of life in prefrail and frail community-dwelling older adults.

Methods

Prefrail and frail individuals were included, as determined by SHARE-FI. Quality of life (QoL) was measured with WHOQOL-BREF and WHOQOL-OLD, DPA with PASE, handgrip strength with a dynamometer, ASMM with bioelectrical impedance analysis and physical performance with the SPPB test. Linear regression models adjusted for sex and age were developed: In model 1, the associations between each independent variable and QoL were assessed separately; in model 2, all the independent variables were included simultaneously.

Results

Eighty-three participants with a mean age of 83 (SD: 8) years were analysed. Model 1: DPA (ß = 0.315), handgrip strength (ß = 0.292) and balance (ß = 0.178) were significantly associated with ‘overall QoL’. Balance was related to the QoL domains of ‘physical health’ (ß = 0.371), ‘psychological health’ (ß = 0.236), ‘environment’ (ß = 0.253), ‘autonomy’ (ß = 0.276) and ‘social participation’ (ß = 0.518). Gait speed (ß = 0.381) and chair stands (ß = 0.282) were associated with ‘social participation’ only. ASMM was not related to QoL. Model 2: independent variables explained ‘overall QoL’ (R² = 0.309), ‘physical health’ (R² = 0.200), ‘autonomy’ (R² = 0.247) and ‘social participation’ (R² = 0.356), among which balance was the strongest indicator.

Conclusion

ASMM did not play a role in the QoL context of the prefrail and frail older adults, whereas balance and DPA were relevant. These parameters were particularly associated with ‘social participation’ and ‘autonomy’.

Sarcopenia, Frailty, and Diabetes in Older Adults

Populations are aging and the prevalence of diabetes mellitus is increasing tremendously. The number of older people with diabetes is increasing unexpectedly. Aging and diabetes are both risk factors for functional disability. Thus, increasing numbers of frail or disabled older patients with diabetes will increase both direct and indirect health-related costs. Diabetes has been reported as an important risk factor of developing physical disability in older adults. Older people with diabetes have lower muscle mass and weaker muscle strength. In addition, muscle quality is poorer in diabetic patients. Sarcopenia and frailty have a common soil and may share a similar pathway for multiple pathologic processes in older people. Sarcopenia is thought to be an intermediate step in the development of frailty in patients with diabetes. Thus, early detection of sarcopenia and frailty in older adults with diabetes should be routine clinical practice to prevent frailty or to intervene earlier in frail patients.

Functional mobility and its contributing factors for older adults in different cities in Taiwan

BACKGROUND/PURPOSE

Impaired mobility is one of the primary causes of declined functional capacity in old age. The timed up-and-go test (TUG), a common mobility test, has been studied extensively in Western countries. The purposes of this study were to compare and identify factors associated with TUG performance in older adults with impaired mobility and living in different cities in Taiwan.

METHODS

Older adults living in Taipei, Tainan, and Niaosong cities were screened for mobility impairments and then recruited. A series of questionnaires and physical and functional tests were used to obtain information and measurements for potential contributing factors and TUG. Regression analysis was conducted to determine factors contributing to TUG.

RESULTS

A total of 413 older adults participated in the study. The mean TUG was 14.3 seconds for participants across the three cities, and was significantly shorter in Tainan. Age, number of medications, fear of falling, depression, high intensity activity time, reaction time, single leg stance time, and functional reach distance were found to have significant contribution. These factors accounted for approximately half of the variance in TUG. The regression equations were not equal for the different cities, with depression being the only common determinant.

CONCLUSION

Taiwanese older adults with mobility problems living in different cities performed differently in TUG and the contributing factors were also different. These findings indicate a need of further studies examining older adults in different environments.

Sex-specific relationships of physical activity, body composition, and muscle quality with lower-extremity physical function in older men and women

OBJECTIVE

This study aims to determine the sex-specific relationships of physical activity, body composition, and muscle quality with lower-extremity physical function in older men and women.

METHODS

Seventy-nine community-dwelling men (n = 39; mean [SD] age, 76.1 [6.2] y; mean [SD] body mass index, 27.3 [3.8] kg/m(2)) and women (n = 40; mean [SD] age, 75.8 [5.5] y; mean [SD] body mass index, 27.0 [3.8] kg/m(2)) were assessed for physical activity via questionnaire, body composition via dual-energy x-ray absorptiometry scanning, leg extension power using the Nottingham power rig, and muscle quality (W/kg; the ratio of leg extension power [W] to lower-body mineral-free lean mass [kg]). A composite measure of physical function was obtained by summing Z scores from the 6-minute walk, 8-ft up-and-go test, and 30-second chair-stand test.

RESULTS

As expected, men had significantly greater levels of physical activity, lower adiposity, greater lean mass, higher leg extension power, and greater muscle quality compared with women (all P < 0.05). In linear regression analyses, muscle quality and physical activity were the strongest predictors of lower-extremity physical function in men and independently explained 42% and 29% of the variance, respectively. In women, muscle quality (16%) and percent body fat (12%) were independent predictors after adjustment for covariates.

CONCLUSIONS

Muscle quality is the strongest predictor of lower-extremity physical function in men and women, but sex impacts the importance of physical activity and adiposity. These findings suggest that older men and women may benefit from different intervention strategies for preventing physical disability and also highlight the importance of weight management for older women to preserve physical function.

Association of adiposity and muscle quality with physical function differs in young and old women

OBJECTIVE

This study aims were to investigate whether age differentially impacts the relationships between adiposity, muscle quality (MQ), and lower-extremity physical function in young and older women.

METHODS

Women aged 20 to 30 years (YOUNG group; n = 37) and women aged 64 to 80 years (OLD group; n = 39) were assessed for body composition via dual-energy X-ray absorptiometry. Isokinetic strength at 60 deg/second was assessed on a dynamometer. MQ was calculated as Nm / mineral-free lean mass (kg). Lower-extremity physical function was determined by an up-and-go (UPGO) challenge.

RESULTS

YOUNG women had lower relative adiposity (%Fat), greater leg lean mass, greater MQ, and faster UPGO time compared with OLD women (all P < 0.01). On linear regression analyses, mineral-free upper leg lean mass was the strongest predictor of UPGO performance in YOUNG women and independently explained 36% of the variance; in OLD women, age and adiposity were the strongest predictors and explained 57% and 40% of the variance, respectively.

CONCLUSIONS

Predictors of lower-extremity physical function differ between young and old women. These findings suggest that body composition and muscle capacity factors associated with function might change across the age span.

Low pulmonary function is related with a high risk of sarcopenia in community-dwelling older adults: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011

Sarcopenia is the age-related reduction of skeletal muscle mass in older individuals. Respiratory muscle strength may be related to skeletal muscle mass and, thus, the present study attempted to estimate the risk of sarcopenia relative to decreased pulmonary function. The present findings demonstrated that low pulmonary function was associated with low muscle mass in community-dwelling older adults.

INTRODUCTION

Lean body mass is related to pulmonary function in patients with chronic obstructive pulmonary disease (COPD). However, the relationship between muscle mass and pulmonary function in healthy older adults has yet to be clarified. Thus, the present study investigated the association of pulmonary function with muscle mass in an older community-dwelling Korean population.

METHODS

This study included 463 disease-free subjects over 65 years of age who underwent anthropometric measurements, laboratory tests, spirometry, and the estimation of appendicular skeletal muscle (ASM) mass in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES). Low muscle mass was defined as the value of ASM divided by height squared (ASM/height(2)) that was less than two standard deviations (SD) below the sex-specific mean of the young reference group.

RESULTS

Forced expiratory volume in 1 s (FEV1[L]) and forced vital capacity (FVC[L]) were positively correlated with ASM/height(2) in males (p < 0.001 and p = 0.001, respectively) but not in females (p = 0.360 and p = 0.779, respectively). A univariate logistic regression analysis revealed that males with low FEV1 or FVC were more likely to have low muscle mass (odds ratio [OR] = 3.11, 95% confidence interval [CI] 1.62-5.99 for FEV1; OR = 1.99, 95% CI 1.13-3.53 for FVC); similar results were found for females, but the significance was lower (OR = 11.37, 95% CI 0.97-132.91 for FEV1; OR = 7.31, 95% CI 1.25-42.74 for FVC). After adjusting for age, smoking, and moderate physical activity, a low FEV1 value was associated with low muscle mass in both males (OR = 2.90, 95% CI 1.50-5.63) and females (OR = 9.15, 95% CI 1.53-54.77).

CONCLUSIONS

Using nationally representative data from the 2008-2011 KNHANES, low pulmonary function was found to be associated with low muscle mass in community-dwelling older Korean adults.

Qualitative Ultrasound in Acute Critical Illness Muscle Wasting

OBJECTIVES

A rapid and early loss of skeletal muscle mass underlies the physical disability common amongst survivors of critical illness. However, skeletal muscle function depends not only on its quantity but its quality, which may be adversely affected. We set out to characterise the changes in macroscopic muscle echogenicity and fascial characteristics that occur early in critical illness, and to relate these to microscopic histologically defined myofibre necrosis and fascial pathology.

DESIGN AND SETTING

Prospective two center observational study.

PATIENTS

Thirty subjects comprising a subgroup of patients recruited to the Musculoskeletal Ultrasound in Critical Illness: Longitudinal Evaluation (MUSCLE) study.

MEASUREMENTS AND MAIN RESULTS

Comparisons were made between sequential Vastus Lateralis histological specimens and ultrasound assessment of Rectus Femoris echogenicity. Change in muscle echogenicity was greater in patients who developed muscle necrosis (n = 15) than in those who did not (8.2% [95% CI, -5.3 to 21.7] vs -15.0% [95% CI, -28.9 to -1.09]; p = 0.016). The area under receiver operator curve for ultrasound echogenicity's prediction of myofiber necrosis was 0.74 (95% CI, 0.565 to 0.919; p = 0.024) increasing to 0.85 (95% CI, 0.703 to -0.995; p = 0.003) with the removal of those with potential iatrogenic muscle damage. Fasciitis was observed in 18 of 30 biopsies (60%).

CONCLUSIONS

Myofiber necrosis and fascial inflammation can be detected noninvasively using ultrasound in the critically ill. Fasciitis precedes and frequently accompanies muscle necrosis. These findings may have functional implications for survivors of critical illness.

Lean Body Mass Associated with Upper Body Strength in Healthy Older Adults While Higher Body Fat Limits Lower Extremity Performance and Endurance

Impaired strength adversely influences an older person’s ability to perform activities of daily living. A cross-sectional study of 117 independently living men and women (age = 73.4 ± 9.4 year; body mass index (BMI) = 27.6 ± 4.8 kg/m²) aimed to assess the association between body composition and: (1) upper body strength (handgrip strength, HGS); (2) lower extremity performance (timed up and go (TUG) and sit to stand test (STS)); and (3) endurance (6-minute walk (SMWT). Body composition (% fat; lean body mass (LBM)) was assessed using bioelectrical impedance. Habitual physical activity was measured using the Minnesota Leisure Time Physical Activity Questionnaire (MLTPA) and dietary macronutrient intake, assessed using 24 h recalls and 3-day food records. Regression analyses included the covariates, protein intake (g/kg), MLTPA, age and sex. For natural logarithm (Ln) of right HGS, LBM (p < 0.001) and % body fat (p < 0.005) were significant (r² = 46.5%; p < 0.000). For left LnHGS, LBM (p < 0.000), age (p = 0.036), protein intake (p = 0.015) and LnMLTPA (p = 0.015) were significant (r² = 0.535; p < 0.000). For SMW, % body fat, age and LnMLTPA were significant (r² = 0.346; p < 0.000). For STS, % body fat and age were significant (r² = 0.251; p < 0.000). LBM is a strong predictor of upper body strength while higher % body fat and lower physical activity are associated with poorer outcomes on tests of lower extremity performance.

Physiological adaptations to resistance training in prepubertal boys

PURPOSE

The purpose of this study was to investigate the physiological adaptations of resistance training (RT) in prepubertal boys.

METHODS

Eighteen healthy boys were divided into RT (n = 9, Mage = 10.4 ± 0.5 years) and control (CTR; n = 9, Mage = 10.9 ± 0.7 years) groups. The RT group underwent a resistance training during 12 weeks, 3 times per week, performing 3 sets of 6 to 15 repetitions at intensities ranging from 60% to 80% of maximal dynamic strength (1-repetition maximum [1-RM] values). Before and after the training, the groups were assessed in their body mass and composition (dual-energy X-ray absorptiometry), isokinetic dynamometry, 1-RM, and ergoespirometry. Moreover, force per unit of muscle volume was calculated by the quotient between 1-RM and lean mass.

RESULTS

Both groups presented statistically significant (p < .05) increases in the 1-RM and force per unit of muscle volume in the knee extension and elbow flexion, but these strength increases were statistically significantly greater in the RT group (effect size [ES] = 2.83-9.00) than in the CTR group (ES = 0.72-1.00). Moreover, both groups statistically significantly increased in lean body mass variables (ES = 0.12-0.38). However, increases in the fat mass variables occurred only in the CTR group (ES = - 0.01-0.50), whereas no changes were observed in the RT group. Furthermore, there were statistically significant increases in all bone mineral content variables (ES = 0.13-0.43), without differences between groups. No cardiorespiratory changes were observed.

CONCLUSION

Twelve weeks of RT was effective in improving strength and force per unit of muscle volume and prevented fat mass increases in boys.

Physical exercise and functional fitness in independently living vs institutionalized elderly women: a comparison of 60- to 79-year-old city dwellers

Purpose

To compare functional fitness (FF) levels among independent-living (IL) and day care (DC) elderly women of different age groups and to analyze changes in FF after 8 months of participation in an exercise program intervention for the IL elderly women.

Materials and methods

A total of 674 elderly women were divided into four IL groups with age in the range of 60–64 years (IL60–64, n=149), 65–69 years (IL65–69, n=138), 70–74 years (IL70–74, n=135), and 75–79 years (IL75–79, n=83), and four DC groups with age in the range of 60–64 years (DC60–64, n=35), 65–69 years (DC65–69, n=34), 70–74 years (DC70–74, n=47), and 75–79 years (DC75–79, n=53). The intervention consisted of a multimodal exercise training, 3 days per week for 8 months. Senior Fitness Test battery performances were obtained at baseline and after 8-month intervention.

Results

Significant differences were identified between all IL groups and DC groups in all FF tests (P<0.001), except between IL70–74 and DC70–74 in the chair sit-and-reach. Analysis of covariance (ANCOVA) identified significant improvements in all FF tests between pre- and posttests in the IL groups (P<0.001), except in the chair sit-and-reach for the IL70–74. ANCOVA also showed a significant declining performance in all FF tests for DC groups (P<0.001), except in the chair sit-and-reach for the DC70–74 and DC75–79.

Conclusion

IL women are more fit than institutionalized DC elderly women. The multimodal training was effective in improving all FF components related to daily living activities, in all age groups. In contrast, institutionalized elderly showed a clear tendency to worsen their FF over the time.