Identification of muscle weakness in older adults from normalized upper and lower limbs strength: a cross-sectional study

Age-related effects on absolute and relative isokinetic knee extensor strength in community-dwelling older men and women at a French geriatric day hospital

PURPOSE

Isokinetic knee extensor strength is poorly evaluated in geriatric day hospitals (GDHs), despite its potential functional significance compared to grip strength. This study aimed to investigate age-related effects on absolute and relative isokinetic knee extensor peak torque (KEPT) data in community-dwelling older GDH patients.

METHODS

A total of 472 French GDH patients (179 men and 293 women, aged 75-94 years) participated in this study. Absolute and relative KEPT were measured at six distinct angular velocities between 0.52 and 3.14 rad/s. In addition, comfortable gait speed and grip strength were assessed. Participants were stratified by sex and age using 5-year intervals. One-way ANOVAs were used to examine age-related effects on KEPT values. Multiple linear regression models were employed to investigate the associations between gait speed and both mean KEPT values and grip strength, with separate models conducted on absolute and relative values.

RESULTS

The recruited GDH patients presented lower absolute and relative KEPT values in comparison with established reference values for healthy community-dwelling older individuals, with men being consistently stronger than women. Notably, there was a significant decline in both absolute and relative KEPT values beyond the age of 85 for both sexes. Importantly, the multiple linear regression analyses conducted revealed a significant positive relationship between gait speed and mean KEPT values, surpassing the association with grip strength.

CONCLUSIONS

These findings underscore the clinical importance of assessing isokinetic knee extensor strength in community-dwelling older GDH patients, particularly for tailoring personalized physical activity interventions.

Cut-off points for knee extension strength: identifying muscle weakness in older adults

PURPOSE

Generalized muscle weakness is the primary characteristic of sarcopenia. Handgrip strength (HGS) is widely employed to detect muscle weakness. However, knee extension strength (KES) declines much earlier and more pronounced than HGS, and there is a stronger correlation between KES and functional performance. Therefore, KES may be a more appropriate proxy for identifying muscle weakness compared to HGS. The purpose of this review was to clarify the KES measurement towards a standardized approach and summarize the cut-off points for KES.

METHODS

A literature search was conducted in Web of Science, PubMed, Elsevier, Scopus and Medline databased up to July 10th, 2023.

RESULTS

A total of 12 articles were ultimately included in this review, which proposed various cut-off points for KES. Notably, these studies exhibited high heterogeneities, including diverse living settings for participants, KES measurement, methods for KES normalization, methodologies for determining cut-off points and study designs.

CONCLUSIONS

No consensus on cut-off points for KES was reached due to the heterogeneities in KES measurement and normalized methods among studies. To enhance the comparability among studies and facilitate the sarcopenia screening framework, a standardized approach for KES measurement and KES normalization are needed. Regarding KES measurement, the hand-held dynamometer-based isometric KES is easy to access and ideally suited for both clinical and community settings, while isokinetic KES, representing the gold standard, is preferred for research settings. Additionally, it is suggested to normalize isometric KES to body weight (BW), while normalizing isokinetic KES to allometrically scaled BW.

Sarcopenic obesity does not impair lower limb strength and physical performance in sufficiently active older adults: a cross-sectional study

This study investigated the associations of sarcopenic obesity (SO) with muscle strength and physical performance in sufficiently active older adults. Data from 72 older sarcopenic obese adults classified as sufficiently active were analyzed. Participants were categorized into four groups based on sex and SO status. Muscle strength/physical performance tests were compared using independent sample t-tests. Multiple linear regression and binary logistic regression were performed to examine the associations between SO and muscle strength and physical performance, adjusting for confounding variables. Only handgrip strength showed differences between SO groups, regardless of sex (p < 0.05). SO negatively explained the variability of handgrip strength (p < 0.05). An increase in handgrip strength values was associated with a decrease in the chances of older adults being classified as SO (p < 0.05). The findings suggest that even with SO, sufficiently active older adults did not present a significant reduction in muscle strength in the lower limbs and physical performance.

Characteristics of resistance training-based protocols in older adults with sarcopenic obesity: a scoping review of training procedure recommendations

Background

Sarcopenic obesity (SO) is a clinical and functional disease characterized by the coexistence of obesity and sarcopenia. Resistance training (RT) characteristics for older adults with sarcopenia or obesity are already well established in the scientific literature. Nonetheless, we still do not know how detailed the RT protocols are described for older adults with SO. Therefore, we aimed to analyze the characteristics of RT programs, including each of their variables, recommended for older adults with SO.

Methods

This is a scoping review study that was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews. The search was carried out until November 2022 in PubMed/MEDLINE, EMBASE, Cochrane Library, Web of Science, Scopus, LILACS, Google Scholar, and medRxiv databases. The studies included SO diagnosis and RT as an intervention strategy. The RT variables analyzed were as follows: exercise selection, the volume of sets, the intensity of load, repetition cadence, rest interval between sets, and weekly frequency.

Results

A total of 1,693 studies were identified. After applying the exclusion criteria, 15 studies were included in the final analysis. The duration of the RT intervention ranged from 8 to 24 weeks. All studies included full-body routines, with single/multi-joint exercises. Regarding the volume of sets, some studies fixed it in three sets, whereas others varied between one and three sets. The load was reported by repetition range and the weight lifted, elastic-band color/resistance, percentage of one repetition maximum, or perceived exertion scale. Repetition cadence was fixed in some studies, while it was self-selected between concentric and eccentric phases in others. The interval between sets of rest varied from 30 to 180 s. All studies reported progression overload during the interventions. Not all studies reported how the exercise selection, repetition cadence, and rest interval were made.

Conclusion

The characteristics of RT protocols and their variables prescribed in the literature for older adults with SO were mapped. The lack of detail on some training variables (i.e., exercise selection, repetition cadence, and rest interval) was identified. RT protocols are heterogeneous and described only partially among studies. The recommendations for RT prescription details in older adults with SO are provided for future studies.

Systematic review registration

https://osf.io/wzk3d/.

Handgrip strength asymmetry cut points to identify slow gait speed in six low- and middle-income countries: A cross-sectional analysis with 12,669 older adults

BACKGROUND

Handgrip strength (HGS) asymmetry is associated with slow gait speed. Both mark muscle dysfunction, potential risk of falls, and adverse health outcomes. This association was found in older adults from high-income countries, but not yet studied in low- and middle-income countries. Moreover, there is no HGS asymmetry referential to identify the disabling process. Thus, our study aims to verify the association of HGS asymmetry with slowness in older adults from six low- and middle-income countries and to propose cut points to slowness.

METHODS

A cross-sectional study with data from 12,669 older adults (≥60 years) of the Study on Global Aging and Adult Health (SAGE) conducted in six low- and middle-income countries were analyzed. Based in the difference between upper body sides HGS (asymmetry), participants were categorized in groups as 0.0-10.0% (reference group), 10.1-20.1%, 20.1-30.0% or >30.0%. Slow gait speed was established as <0.59 (men) and <0.51 (women) m/s. Associations of HGS asymmetry with gait speed were ascertained with logistic regression. HGS asymmetry index "[(HGS asymmetry*HGS)/(BMI*Age)]*100" cut points to identify slowness were generated with the ROC curve and Youden index (α = 5%).

RESULTS

Compared to HGS reference group, those with HGS asymmetry of 10.1-20%, 20.1-30.0% and >30.0% had a superior odds for slowness [1.18(CI:1.02,1.42); 1.17(CI: 0.97; 1.44); and 1.21(CI:1.03;1.43), respectively]. HGS asymmetry index cut points to identify slowness were ≤1.14 (women) and ≤1.77 (men).

CONCLUSIONS

HGS asymmetry association with slowness is present in economically disadvantaged countries. We proposed a new index for impaired muscle function with acceptable sensibility and specificity.

The Effects of Different Exercise Training Types on Body Composition and Physical Performance in Older Adults with Sarcopenic Obesity: A Systematic Review and Meta-Analysis

OBJECTIVES

To carry out a systematic review and meta-analysis to verify the effects of different exercise training types on body composition and physical performance in older adults with sarcopenic obesity (SO).

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

Older adults (≥60 years).

METHODS

Database searches were performed in MEDLINE (via PubMed), EMBASE, Cochrane Library, Web of Science, SCOPUS, and LILACS on January 10th, 2023. We included: randomized and/or controlled clinical trials; physical exercise as an intervention; analysis of body composition and/or muscle function; and sarcopenic obesity diagnosis. We used the Risk of Bias 2 tool and PEDro scale. The GRADE certainty of evidence was also performed.

RESULTS

Fourteen studies were included in the systematic review and nine studies in the meta-analysis. A decrease in body fat (%) favoring the exercise group was identified (SMD: -0.34 [95% CI: -0.53 to -0.16]; p=0.0003) (GRADE: ⊕⊕⊕◯ Moderate). Only resistance training showed fat reduction (SMD: -0.27 [95% CI: -0.48 to -0.06]; p=0.01). Increases in upper (SMD: 0.41 [95% CI: 0.04 to 0.78]; p=0.03) (GRADE: ⊕⊕◯◯ Low) and lower (SMD: 0.80 [95% CI: 0.22 to 1.39]; p=0.007) (GRADE: ⊕⊕⊕⊕ High) limb strength was identified with exercise. Chair stand test showed increases with exercise (SMD: 0.73 [95% CI: 0.40 to 1.07]; p<0.0001) (GRADE: ⊕⊕⊕⊕ High), especially for resistance training (SMD: 0.62 [95% CI: 0.21 to 1.02]; p=0.003) and combined training (SMD: 0.99 [95% CI: 0.40 to 1.57]; p=0.0005). The PEDro scale for the studies in our review ranged from 3 to 8 (mean = 5.8 (1.6)), meaning fair methodological quality, and most studies were overall judged with at least low/some concerns in terms of risk of bias.

CONCLUSION AND IMPLICATIONS

Overall, moderate to high certainty of evidence was found for body fat, lower limb strength, and chair stand test. On the other hand, low certainty of evidence was found for upper limb strength. Resistance, combined, and aerobic training evoked divergent results between the variables analyzed. Although promising, our results should be considered sparingly, but may guide additional exercise recommendations to improve specific health parameters in older adults with SO.

Foreign allometric exponents adequately normalize isokinetic knee extension strength to identify muscle weakness and mobility limitation in Portuguese older adults: a cross-sectional study

Background

Identifying muscle weakness is challenging, because the reduction of strength with aging does not depend only on sarcopenia, but also on sensorimotor deficits. Nevertheless, this identification is improved by adjusting muscle strength allometrically, by removing the influence of body size. However, the effectiveness of foreign models to normalize these (dys)functionalities is not yet tested. This study aimed to compare and apply foreign allometric exponents for normalizing isokinetic knee extension strength in Portuguese older adults to identify muscle weakness/mobility limitation. Additionally, to attest any populational difference, data of these people and Brazilian older adults were compared

Methods

This is a cross-sectional study encompassing 226 Portuguese (n = 132) and Brazilian (n = 94) older adults. Mobility limitation (six-minute walk test, at lowest quartile), lower limb strength (knee extension isokinetic strength at 60º/s), and body dimensions measures were taken. Foreign allometric exponents (^b) were used to normalize Portuguese strength (strength/body-size variables^b). Non-normalized and normalized strength were compared (ROC) to generate the most accurate cut-point for identifying muscle weakness/mobility limitation.

Results

Older Portuguese men and women had better mobility than their Brazilian counterparts. Older Portuguese women had superior muscle strength to Brazilian women. Normalization from 11 foreign models removed the influence of body size on muscle strength, with a negligible correlation (r ≤ 0.30). In contrast to the non-normalized strength, the normalized strength cut-off points were sufficiently accurate (AUC ≥ 0.70) to avoid identifying false-negative cases of weakness/mobility limitation.

Conclusions

Portuguese older women were stronger and had superior functional capacity compared to Brazilian ones. Normalized foreign models improved the accuracy in identifying muscle weakness/mobility limitation in Portuguese older adults. The isokinetic knee extension muscle strength normalized, even using foreign allometric exponents, should be better than no adjustment.

Muscle Weakness and Walking Slowness for the Identification of Sarcopenia in the Older Adults from Northern Brazil: A Cross-Sectional Study

Background: This study aimed to analyze the prevalence of sarcopenia in elderly people from Northern Brazil according to muscle weakness or walking slowness. Methods: The sample consisted of 312 elderly people (72.6 ± 7.8 years). For walking slowness, a gait speed ≤ 0.8 m/s was used as a cut-off value, and for muscle weakness the following handgrip strength criteria were used for men and women, respectively: CI: <27.0/16.0 kg; CII: <35.5/20.0 kg; CIII: grip strength corrected for body mass index (BMI) < 1.05/0.79; CIV: grip strength corrected for total fat mass: <1.66/0.65; CV: grip strength corrected for body mass: <0.45/0.34. Results: Walking speed was reduced in 27.0% of women and 15.2% of men (p < 0.05). According to grip strength criteria, 28.5% of women and 30.4% of men (CI), 58.0% of women and 75.0% of men (CII), 66.0% of women and 39.3% of men (CIII), 28.8% of women and 19.6% of men (CIV), and 56.5% of women and 50.0% of men (CV) were identified as having sarcopenia. Conclusions: Walking slowness is more prevalent in women and muscle weakness is more prevalent in men in Northern Brazil. Walking slowness proved to be more concordant with muscle weakness in both sexes when the CI for handgrip strength was adopted.