Full characterisation of knee extensors' function in ageing: effect of sex and obesity

Stair climb muscle power is associated with gait speed, sit-to-stand performance, patient-reported outcomes and objective measures of mechanical muscle function in individuals with knee osteoarthritis - secondary analysis from an RCT

BACKGROUND

Mechanically measured leg extensor muscle power (LEP) predicts functional performance, patient-reported outcomes (PROMs) and mechanical muscle function in patients with knee osteoarthritis (OA). The stair climb test (SCT) have been used to assess LEP in clinical populations, but the relationship between SCT derived LEP and functional- and self-reported outcome measures in patients with knee-OA remains unknown.

OBJECTIVES

To investigate the relationship between LEP derived from SCT, and patient-reported outcomes (PROMs), functional performance, knee extensor muscle strength (MVIC), rate of force development (RFD) and Nottingham LEP in individuals with knee-OA.

DESIGN

Cross-sectional study.

METHOD

SCT power was obtained in 96 knee-OA patients (age 56.9 ± 7.7 yr. males n = 47, females n = 49). The dependent variable was SCT power, while independent variables included 4 × 10 m fast-paced walk (4x10m-FWT), sit-to-stand (STS), STS power, KOOS, Oxford Knee Score (OKS), LEP, MVIC, and RFD.

RESULTS

There were strong correlations (r = 0.72-0.80, p < 0.01) between SCT power and 4x10m-FWT and STS. There were weak-to-moderate correlations (r = 0.22-0.42, p < 0.05) between SCT power versus OKS and all KOOS subscales. Moderate correlations were observed between SCT power and Nottingham LEP, MVIC, and RFD (r = 0.53-0.64, p < 0.01).

CONCLUSIONS

SCT power correlates positively with functional performance, PROMs and mechanical lower limb muscle function in male and female individuals with knee-OA.

Body composition and functional capacity as determinants of physical activity in middle-aged and older adults: a cross-sectional analysis

BACKGROUND

Body composition and functional capacity are both related to physical activity, but the interplay is complex, as different body tissue types contribute differently on physical activity and functional capacity. To clarify the role of body composition and functional capacity as determinants of physical activity in aging, we investigated the associations of different body tissue types, muscle strength, and walking capacity with physical activity in middle-aged and older adults.

METHODS

This cross-sectional study involved 1158 women aged 47-55 years, and community-dwelling 289 women and 196 men aged 75, 80, or 85 years. Their physical activity was assessed with accelerometers, muscle mass and muscle-free mass with bioelectrical impedance analysis, walking performance with a six-minute walking test, and muscle strength with maximal isometric knee extension test. The associations of muscle mass, muscle-free mass, walking performance, and muscle strength with physical activity were studied separately for middle-aged women, older women, and older men using linear regression and structural equation models.

RESULTS

Total body mass and absolute muscle-free mass were inversely associated with the level of physical activity in all study groups. Furthermore, walking performance, muscle strength, and muscle mass relative to body weight, but not absolute muscle mass, were directly associated with the level of physical activity. The associations between the measures of body composition and physical activity were fully explained by the differences in functional capacity, as defined by both walking performance and muscle strength, in structural equation models. Functional capacity was strongly associated with higher levels of physical activity regardless of body composition, especially among older people: β = 0.70, SE = 0.10 for older women, β = 0.92, SE = 0.27 for older men, and β = 0.41, SE = 0.10 for middle-aged women.

CONCLUSIONS

Reduced functional capacity may be a key factor limiting physical activity, with its impact becoming more pronounced as functional capacity declines with age. Based on these findings, maintaining and improving functional capacity is essential for promoting an active lifestyle in older adults.

Effects of a Hypocaloric Diet Plus Resistance Training with and Without Amino Acids in Older Participants with Dynapenic Obesity: A Randomized Clinical Trial

BACKGROUND/OBJECTIVES

Exercise and nutrition may be useful strategies in dynapenic and sarcopenic obesity management, but the identification of treatment modalities aimed at improving this condition is still lacking. We compared the effect of a five-month hypocaloric diet plus resistance training (RT) with and without essential amino acids (EAAs) on body composition, physical performance, and muscle strength among older adults with dynapenic obesity (DO).

METHODS

Older individuals (n = 48) with DO [(BMI ≥ 30 kg/m2 and/or high waist circumference and low handgrip strength (HGS)] were randomized into two double-blind groups (RT without EAAs vs. RT+EAAs). All participants followed a hypocaloric diet (1 g of proteins/kg spread over three meals) and RT for five months. Pre- and post-intervention assessments included the body composition (DXA), Short Physical Performance Battery (SPPB), HGS, one-repetition maximum (1-RM), and maximal isometric torque with an isokinetic dynamometer.

RESULTS

Both groups reduced body mass (RT: -4.66 kg; RT+EAAs: -4.02 kg), waist circumference (RT: -4.66 cm; RT+EAAs: -2.2 cm), total fat mass (RT: -3.81 kg; RT+EAAs: -3.72 kg), and compartmental fat mass with no between-group differences. Both groups improved 1-RM strength (33-47%), isometric torque for body mass (RT: 14.5%; RT+EAAs: 10.6%), and functional performance (chair stand (RT: -3.24 s; RT+EAAs: -1.5 s) and HGS (RT: -2.7 kg; RT+EAAs: 2.9 kg)) with no between-group differences.

CONCLUSIONS

A moderate hypocaloric diet combined with RT improves body composition and physical function in DO participants, but EAA supplementation did not provide additional benefits.

The diagnostic agreement of sarcopenic obesity with different definitions in Chinese community-dwelling middle-aged and older adults

Background

In 2022, the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched a consensus on the diagnostic methods for sarcopenic obesity (SO). The study aimed to identify the prevalence and diagnostic agreement of SO using different diagnostic methods in a cohort of subjects from West China aged at least 50 years old.

Methods

A large multi-ethnic sample of 4,155 participants from the West China Health and Aging Trend (WCHAT) study was analyzed. SO was defined according to the newly published consensus of the ESPEN/EASO. Furthermore, SO was diagnosed as a combination of sarcopenia and obesity. The criteria established by the Asian Working Group for Sarcopenia 2019 (AWGS2019) were used to define sarcopenia. Obesity was defined by four widely used indicators: percent of body fat (PBF), visceral fat area (VFA), waist circumference (WC), and body mass index (BMI). Cohen's kappa was used to analyze the diagnostic agreement of the above five diagnostic methods.

Results

A total of 4,155 participants were part of the study, including 1,499 men (63.76 ± 8.23 years) and 2,656 women (61.61 ± 8.20 years). The prevalence of SO was 0.63-7.22% with different diagnostic methods. The diagnosis agreement of five diagnostic methods was poor-to-good (κ: 0.06-0.67). The consensus by the ESPEN/EASO had the poorest agreement with other methods (κ: 0.06-0.32). AWGS+VFA had the best agreement with AWGS+WC (κ = 0.67), and consensus by the ESPEN/EASO had the best agreement with AWGS+ PBF (κ = 0.32).

Conclusion

The prevalence and diagnostic agreement of SO varies considerably between different diagnostic methods. AWGS+WC has the highest diagnostic rate in the diagnosis of SO, whereas AWGS+BMI has the lowest. AWGS+VFA has a relatively good diagnostic agreement with other diagnostic methods, while the consensus of the ESPEN/EASO has a poor diagnostic agreement. AWGS+PBF may be suitable for the alternative diagnosis of the 2022 ESPEN/EASO.

Temporal, Kinematic and Kinetic Variables Derived from a Wearable 3D Inertial Sensor to Estimate Muscle Power during the 5 Sit to Stand Test in Older Individuals: A Validation Study

The 5-Sit-to-stand test (5STS) is widely used to estimate lower limb muscle power (MP). An Inertial Measurement Unit (IMU) could be used to obtain objective, accurate and automatic measures of lower limb MP. In 62 older adults (30 F, 66 ± 6 years) we compared (paired t-test, Pearson's correlation coefficient, and Bland-Altman analysis) IMU-based estimates of total trial time (totT), mean concentric time (McT), velocity (McV), force (McF), and MP against laboratory equipment (Lab). While significantly different, Lab vs. IMU measures of totT (8.97 ± 2.44 vs. 8.86 ± 2.45 s, p = 0.003), McV (0.35 ± 0.09 vs. 0.27 ± 0.10 m∙s^-1, p < 0.001), McF (673.13 ± 146.43 vs. 653.41 ± 144.58 N, p < 0.001) and MP (233.00 ± 70.83 vs. 174.84 ± 71.16 W, p < 0.001) had a very large to extremely large correlation (r = 0.99, r = 0.93, and r = 0.97 r = 0.76 and r = 0.79, respectively, for totT, McT, McF, McV and MP). Bland-Altman analysis showed a small, significant bias and good precision for all the variables, but McT. A sensor-based 5STS evaluation appears to be a promising objective and digitalized measure of MP. This approach could offer a practical alternative to the gold standard methods used to measure MP.

Knee flexor and extensor torque ratio in elderly men and women with and without obesity: a cross-sectional study

BACKGROUND

With aging and obesity lower limb torque deteriorates. Importantly, the ratio between knee flexor (KF) and extensor (KE) torque is an indicator of joint stability.

AIMS

We compared KF torque and KF/KE ratio in older subjects of both sexes with obesity (OB) or without (NOB) obesity.

METHODS

The maximal torque during KE and KF isokinetic contractions were evaluated at: 60, 90, 150, 180 and 210 deg/s in 89 elderly (68 ± 5 years) subjects with NOB (BMI < 30 kg/m²) and OB (BMI ≥ 30 kg/m²). Values were normalised for body weight (BW) and leg lean mass (i.e., muscle quality).

RESULTS

At all speeds men had higher absolute KF values (P < 0.001). When values were normalised for BW, sex differences remain in favour of men (P < 0.001) with lower values in both groups with OB than NOB (P < 0.001). Muscle quality and KF/KE ratio were lower in OB than NOB (P < 0.001).

CONCLUSIONS

The KF torque and KF/KE ratio decline with aging and with OB. In all groups, the KF/KE ratio was below the joint stability threshold. Thus, exercise physiologists should include exercises designed to train both KE and KF in older subjects with OB.

Proprioceptive Training for Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: There is increased interest in proprioceptive training for knee osteoarthritis (KOA). However, little consensus supports the effectiveness of this intervention. Objective: This meta-analysis aimed to assess the effects of proprioceptive training on symptoms, function, and proprioception in people with KOA. Methods: The PubMed, Cochrane Library, Web of Science, and EMBASE databases were systematically searched from the inception dates to April 16, 2021 for relevant randomized controlled trials (RCTs). Data were pooled by calculating the standardized mean differences (SMDs) and 95% confidence intervals (CIs). A random-effects model was used for the analyses. Results: A total of 24 RCTs involving 1,275 participants were included in our analysis. This study indicated that compared to no intervention, proprioceptive training significantly improved pain, stiffness, physical function, joint position sense (JPS), muscle strength, mobility, and knee ROM (P < 0.05) in people with KOA. When compared to other non-proprioceptive training, proprioceptive training provided better results in terms of JPS (SMD = -1.28, 95%CI: [-1.64, -0.92], I 2 = 0%, P < 0.00001) and mobility (timed walk over spongy surface) (SMD = -0.76, 95%CI: [-1.33, -0.18], I 2 = 64%, P = 0.01), and other results are similar. When proprioceptive training plus other non-proprioceptive training compared to other non-proprioceptive training, the two groups showed similar outcomes, but there was a greater improvement for JPS (SMD = -1.54, 95%CI: [-2.74, -0.34], I 2 = 79%, P = 0.01), physical function (SMD = -0.34, 95%CI: [-0.56, -0.12], I 2 = 0%, P = 0.003), and knee ROM (P < 0.05) in the proprioceptive training plus other non-proprioceptive training group. When proprioceptive training plus conventional physiotherapy compared against conventional physiotherapy, the two groups demonstrated similar outcomes, but there was a significant improvement for JPS (SMD = -0.95, 95%CI: [-1.73, -0.18], I 2 = 78%, P = 0.02) in the proprioceptive training plus conventional physiotherapy group. Conclusions: Proprioceptive training is safe and effective in treating KOA. There is some evidence that proprioceptive training combined with general non-proprioceptive training or conventional physiotherapy appears to be more effective and should be considered as part of the rehabilitation program. However, given that the majority of current studies investigated the short-term effect of these proprioceptive training programs, more large-scale and well-designed studies with long-term follow up are needed to determine the long-term effects of these proprioceptive training regimes in KOA. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#recordDetails, PROSPERO, identifier: CRD42021240587.