Handgrip Strength Asymmetry is Associated with Slow Gait Speed and Poorer Standing Balance in Older Americans

Framework for a short muscle function battery using electronic handgrip dynamometry and accelerometry in older adults

BACKGROUND

Electronic handgrip dynamometry and accelerometry enables novel opportunities to collect additional attributes of muscle function beyond just maximal strength, but some muscle function attributes may already be related, which may warrant discerning these attributes into a short muscle function battery (SMFB).

OBJECTIVES

We sought to determine the multivariate relationships between maximal strength, asymmetry, submaximal control, rate of force development, bimanual coordination, fatigability, and contractile steadiness in older adults.

DESIGN

A cross-sectional design was used for this investigation.

SETTING

Laboratory.

PARTICIPANTS

The analytic sample included 121 generally healthy older adults aged 70.7 ± 4.7 years.

MEASUREMENTS

Electronic handgrip dynamometry and accelerometry measured strength, asymmetry, submaximal control, rate of force development, bimanual coordination, fatigability, and contractile steadiness. The handgrip variables were standardized before they were included in a factor analysis. Factors with eigenvalues >1.0 were kept. Items within a factor with a loading |>0.30| were similarly retained.

RESULTS

There were 3 factors retained with eigenvalues of 1.88, 1.56, and 1.10. The first factor (functional strength), which explained 39.9 % of the variance, included strength, submaximal control, and rate of force development. Factor 2 (lateral function), which explained 35.8 % of the variance, included asymmetry and bimanual coordination. The third factor (muscle endurance), which explained 24.3 % of the variance, included fatigability and contractile steadiness.

CONCLUSIONS

Our findings suggest the surfacing of themes in the additional muscle function measures, thereby providing framework for a SMFB. More research is needed for electronic handgrip dynamometry and accelerometry derived muscle function on health before consideration of implementation in clinical practice.

Handgrip strength and asymmetry are associated with lower-body muscle power in older women

BACKGROUND

The difference in strength between hands, as characterized by handgrip asymmetry, has been shown to be significantly associated with several adverse health outcomes. Handgrip strength asymmetry and its relationship with lower-body muscle power in older adults is not well understood. This study aimed to determine if handgrip strength and asymmetry are associated with lower-body muscle power in older women.

METHODS

Twenty active older women (67±5 years) participated in this study. Handgrip contractions were performed with the dominant and non-dominant hand to assess strength measurements of peak force, peak rate of force development (RFD), and RFD at 0-100 (RFD100) and 0-200 (RFD200) ms. Asymmetry ratios were used to determine the severity of differences in handgrip peak force and RFD measurements between the dominant and non-dominant hand. Lower-body peak muscle power was assessed from a vertical jump test.

RESULTS

All handgrip peak force and RFD measurements for the dominant and non-dominant hands were significantly associated with vertical jump peak power (r=0.445-0.547, P=0.013-0.049). Significant correlations were observed between vertical jump peak power and handgrip asymmetry ratios for peak RFD (r=-0.460, P=0.041) and RFD100 (r=-0.591, P=0.006). Multiple regression analysis indicated that handgrip RFD100 asymmetry ratio and RFD200 for the dominant hand were significant predictors of vertical jump peak power, and together, explained 53.9% of its variance.

CONCLUSIONS

These findings suggest that handgrip RFD and asymmetry may be effective measurements at predicting lower-body muscle power in older women.

Association of handgrip strength asymmetry and weakness with intrinsic capacity impairment among older adults in China

BACKGROUND

Declining intrinsic capacity (IC) significantly impacts health outcomes in aging populations. While weak handgrip strength (HGS) is associated with IC impairment, the role of HGS asymmetry remains unclear, especially among older Chinese cohorts.

METHODS

We included participants aged ≥60 years from the 2015 wave of the China Health and Retirement Longitudinal Study (CHARLS). IC was evaluated across cognitive, locomotion, psychological, sensory, and vitality domains. Asymmetry and weakness were measured using the maximum value of HGS. Logistic regression models were employed to examine the association of the individual and combined groupings of HGS asymmetry and weakness with IC impairment (a total score ≥ 2 across five domains). The potential non-linear relationship was explored using a restricted cubic spline (RCS) model.

RESULTS

Of the 4798 participants included (median age 66.0 years, IQR 63.0-71.0 years; 56.9 % male), 35.2 % had IC impairment. HGS asymmetry (OR = 1.26, 95 % CI: 1.11-1.43) and weakness (OR = 2.09, 95 % CI: 1.78-2.45) were both independent risk factors for IC impairment. Notably, participants experiencing both HGS asymmetry and weakness were at even higher risk of IC impairment (OR = 2.47, 95 % CI: 1.99-3.08), suggesting compounded effects on IC. Further subgroup analysis showed significant associations between HGS status and impairments in specific IC domains, particularly in locomotion. In contrast to other domains, it was the Weakness only group, rather than the Both group, that had the highest risk of vitality impairment. There was a U-shaped relationship between HGS asymmetry and IC impairment.

CONCLUSIONS

HGS asymmetry and weakness were associated with an increased risk of composite and individual domain IC impairment. Assessing and maintaining HGS symmetry and strength may have implications for the early identification of individuals at risk for IC impairment and the prevention of related adverse health outcomes.

Association of handgrip strength weakness and asymmetry with low physical performance among Chinese older people

BACKGROUND

Handgrip strength (HGS) weakness and asymmetry are both abnormal conditions of upper-limb muscle strength. The association between HGS weakness and physical performance is controversial, and the link between HGS asymmetry and physical performance remains unclear.

AIMS

This study aimed to investigate the associations of HGS weakness and asymmetry separately and concurrently with low physical performance among Chinese older people.

METHODS

The study used two waves of data from China Health and Retirement Longitudinal Study (CHARLS) in 2013 and 2015. HGS weakness and asymmetry were defined according to the maximal HGS and the HGS ratio, respectively. Participants were classified into 4 groups according to HGS status: normal, asymmetry only, weakness only, and concurrent weakness and asymmetry. The logistic regression model was used to investigate the cross-sectional association between low physical performance and each of maximal HGS, HGS ratio, and HGS status, as well as the prospective association between baseline HGS status and new-onset physical performance decline after two years.

RESULTS

Participants with HGS asymmetry only, weakness only, and two abnormalities showed a higher prevalence of low physical performance when asymmetry defined as an HGS ratio exceeding 1.20 and 1.30 (all, p < 0.001), with the greatest odds in those with two abnormalities (20% threshold: OR 3.83; 30% threshold: OR 5.41). The longitudinal analysis found that HGS weakness can predict the new-onset low physical performance over a two-year period, with concurrent HGS asymmetry further increased the future risk of physical performance decline.

CONCLUSIONS

Both HGS weakness and asymmetry were associated with a higher prevalence of low physical performance, in an additive way. This study will help screen older people with low physical performance more efficiently, and identify those at higher risk of developing new-onset physical performance decline within two years.

A hand-in-hand phenomenon in older adults: Increased risk of frailty in geriatric outpatients associated with handgrip strength asymmetry and weakness

OBJECTIVES

Handgrip strength (HGS) is accepted as a predictor of overall health status and a biomarker of aging, besides negative health outcomes and mortality. While differences in HGS between the dominant and non-dominant hands are expected, substantial discrepancies may signal impaired muscle function. This study aims to investigate whether handgrip asymmetry can serve as a reliable indicator of frailty in a diverse population of older adults.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A total of 512 patients aged 65 years and older who were admitted to the geriatric medicine outpatient clinic of a university hospital were enrolled in the study.

METHODS

The Clinical Frailty Scale (CFS) was used to assess the overall level of frailty of the study population. The highest recorded HGS values from the non-dominant and dominant hand were used to calculate the HGS ratio. Those with a HGS ratio of dominant and non-dominant hand <0.90 or >1.10 were defined as HGS asymmetry.

RESULTS

Of the whole study group, 61.1% was female and the mean age was 73.2 ± 6.1 years. The ratio of the participants living with frailty was 57.6% (n = 219). The number of patients with HGS asymmetry was 264 (51.6%), and 48.4% (n = 248) of the study population had symmetric HGS. The normal and symmetric HGS was found in 40.2% of the non-frail group, whereas it was 23.7% in patients living with frailty. Furthermore, the ratio of low and asymmetric HGS was 16.3% in the non-frail group, and 35.0% in the patients living with frailty (p < 0.001). The presence of asymmetric and low HGS increased the risk of frailty three times independently of other confounding factors (OR:3.08; 95% CI:1.48-6.43; p = 0.003).

CONCLUSIONS AND IMPLICATIONS

Identifying HGS asymmetry along with low HGS as potential indicators of frailty may provide clinicians with a clear and quantifiable criterion for assessing older patients.

Relationship of Handgrip Strength and Asymmetry with Walking Ability in Older Adults with Excess Adiposity

When low muscle mass and impaired strength and physical function coexist with excess adiposity, it is termed sarcopenic obesity (SO). Handgrip strength (HGS) is a predictor of disability and mortality. Asymmetry in HGS, particularly ≥ 10% strength differences between hands, may indicate neuromuscular dysfunction observable prior to declines in maximal strength are detectedand therefore could be incorporated to identify those at risk of physical limitations and SO. This study compares HGS values and asymmetry in older adults with excess adiposity and evaluates their relationships with physical function. Baseline data from two previous pilot weight loss studies in 85 older adults with body mass index values ≥ 30 kg m-2 are included with measures of body composition, walking speed, and chair stand ability. Sixty-three participants met the criteria for SO. HGS correlated to gait speed (r = 0.22), distance walked (r = 0.40), chair stand time for 5 repetitions (r = 0.42) and during 30 s (r = 0.31). HGS asymmetry is only correlated to gait speed (r = 0.31) and there are no differences in physical function between those with and without asymmetry. Maximal HGS tests should continue to be used to screen for functional decline and disability.

Validity of handgrip strength for assessing cognition and psychotic symptoms in hospitalized patients with stable schizophrenia

BACKGROUND AND OBJECTIVES

A correlation between low handgrip strength (HGS), HGS asymmetry, and low cognitive performance has been demonstrated. However, it remains unclear whether low HGS is associated with psychotic symptoms and whether HGS asymmetry is associated with cognitive and psychotic symptoms in hospitalized patients with schizophrenia. This study aimed to investigate the validity of HGS as a measure for assessing cognition and psychotic symptoms in hospitalized patients with stable schizophrenia.

METHODS

A total of 235 inpatients with stable schizophrenia were recruited between August 1, 2023, and August 31, 2023. The highest HGS values from three tests on the dominant hand were used to determine low HGS (male < 28 kg, female < 18 kg), and HGS asymmetry was identified when the non-dominant HGS/dominant HGS ratio was outside 0.9-1.1. Cognition and psychotic symptoms were assessed using the Chinese Montreal Cognitive Assessment (MoCA-C) and Positive and Negative Syndrome Scale (PANSS). Generalized linear model analyses examined the relationship between HGS and scale scores.

RESULTS

Covariate-adjusted generalized linear models confirmed a strong association between low HGS alone and the MoCA-C score (OR = 0.819, 95% CI = 0.710‒0.945, p = 0.006) and PANSS score (OR = 1.113, 95% CI = 1.036‒1.239, p = 0.006). Similarly, the combination of low and asymmetric HGS was strongly associated with both MoCA-C (OR = 0.748, 95% CI = 0.653‒0.857, p<0.001) and PANSS scores (OR = 1.118, 95% CI = 1.032‒1.211, p = 0.006).

CONCLUSIONS

The results suggest that hospitalized patients with schizophrenia and low HGS, with or without asymmetry, are likely to have lower MoCA-C scores and higher PANSS scores. Screening stable schizophrenia patients with low HGS, with or without asymmetry, could be a valuable and straightforward approach to identifying those with lower cognition and severe psychotic symptoms.

Low handgrip strength with asymmetry is associated with elevated all-cause mortality risk in older Chinese adults with abdominal obesity

BACKGROUND AND OBJECTIVES

Low handgrip strength (HGS) and abdominal obesity (AO) have been reported to be linked to an increased all-cause mortality risk in older adults. However, the combined impact of AO with low HGS and/or HGS asymmetry on mortality risk remains unclear. Therefore, this study aimed to investigate the synergistic effects of AO and abnormal HGS on mortality risk among Chinese older adults.

METHODS

Baseline data of the China Health and Retirement Longitudinal Study in 2011, along with mortality outcomes obtained in 2018 were used for the analysis. Low HGS was identified as HGS <18 kg in women or <28 kg in men, while HGS asymmetry is defined as an HGS of either hand > 10% stronger than the other. AO was characterized by a waist circumference ≥90 cm in men and ≥85 cm in women. Logistic regression analysis was used to evaluate the relationship between AO, abnormal HGS and mortality risk.

RESULTS

A total of 5186 subjects aged 60 years or older were enrolled, 50.6% of whom were male. The proportions of participants with only AO, only low HGS, only HGS asymmetry, low HGS with asymmetry, both AO and low HGS, both AO and asymmetric HGS, and AO with both low HGS and asymmetry were 20.0%, 6.1%, 16.6%, 8.3%, 3.2%, 13.4%, and 3.9%, respectively. Over the course of a 7-year follow-up interval, 970 of these individuals died, with 13.4%, 12.4%, 13.6%, 15.5%, 4.1%, 10.1% and 6.9% of deaths in the above groups, respectively. The adjusted logistic regression analysis model confirmed that only low HGS (OR = 1.897, 95%CI: 1.386-2.596, p<0.001), low HGS with asymmetry (OR = 1.680, 95%CI: 1.265-2.231, p<0.001), and AO combined with both low HGS and asymmetry (OR = 2.029, 95%CI: 1.381-2.981, p<0.001) were associated with a higher risk of mortality.

CONCLUSIONS

Low HGS, with or without asymmetry, is associated with increased mortality risk in older Chinese adults without AO, and the combination of low HGS and HGS asymmetry further elevates mortality risk in those with AO.

High-Impact Pain Is Associated With Epigenetic Aging Among Middle-Aged and Older Adults: Findings From the Health and Retirement Study

BACKGROUND

Chronic pain has been associated with accelerated biological aging, which may be related to epigenetic alterations. We evaluated the association of high-impact pain (ie, pain that limits activities and function) with epigenetic aging, a measure of biological aging, in a nationally representative sample of middle-aged and older adults in the United States.

METHODS

Cross-sectional analysis of adults 50 years of age and older from the 2016 Health and Retirement Study. Epigenetic aging was derived from 13 epigenetic clocks based on DNA methylation patterns that predict aging correlates of morbidity and mortality. Ordinary least squares regressions were performed to test for differences in the epigenetic clocks, adjusting for the complex survey design, as well as biological, social, and behavioral factors.

RESULTS

The analysis consisted of 3 855 adults with mean age of 68.5 years, including 59.8% with no pain and 25.8% with high-impact pain. Consistent with its operational definition, high-impact pain was associated with greater functional and activity limitations. High-impact pain was associated with accelerated epigenetic aging compared to no pain, as measured via second (Zhang, PhenoAge, GrimAge) and third (DunedinPoAm) generation epigenetic clocks. Additionally, GrimAge was accelerated in high-impact pain as compared to low-impact pain.

CONCLUSIONS

High-impact pain is associated with accelerated epigenetic aging among middle-aged and older adults in the United States. These findings highlight aging-associated epigenetic alterations in high-impact chronic pain and suggest a potential for epigenetic therapeutic approaches for pain management and the preservation of physical function in older adults.

Association between handgrip strength weakness and asymmetry with incident hip fracture among older Chinese adults

BACKGROUND

To evaluate the association between handgrip strength (HGS) weakness and asymmetry with incident hip fracture among older Chinese adults.

METHODS

Data was obtained from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). HGS weakness was defined as maximal HGS 〈 28 kg in men and < 18 kg in women. HGS asymmetry was defined as the HGS ratio < 0.9 or 〉 1.1. Participants were categorized into normal HGS, weakness only, asymmetry only, and both weakness and asymmetry. Given the sex differences in HGS, the association between HGS weakness and asymmetry was analyzed by sex using the multivariable logistic regression models.

RESULTS

A total of 4789 participants aged ≥ 60 years old without hip fracture at baseline were included in the final analysis. Over the four-year follow-up, there were 152 (3.17 %) participants having incident hip fractures, of which 69 (2.90 %) were men and 83 (3.45 %) were women. Compared to the normal group, men with both weakness and asymmetry had a significantly higher risk of incident hip fracture in the fully adjusted model (adjusted odds ratio (OR): 2.31, 95 % confidence interval (CI):1.17-4.52). There was no significant association between HGS asymmetry and weakness with hip fracture in women.

CONCLUSIONS

Our findings indicated that among the Chinese population, men with both HGS weakness and asymmetry were associated with increased odds of hip fracture, while no significant association was observed in women.

Risk factors associated with weak and asymmetric handgrip strength in older Chinese adults

OBJECTIVES

This study sought to investigate the potential risk factors associated with weak and asymmetric handgrip strength (HGS) in older Chinese adults.

METHODS

A total of 2702 participants aged ≥65 years from the two waves of data (2011 and 2013) from the China Health and Retirement Longitudinal Study were analyzed. The highest recorded HGS values (Method A) or the average HGS values (Method B) for the dominant hand were used to compute the HGS asymmetry (nondominant HGS/dominant HGS out of 0.9-1.1) and HGS weakness (male <28 kg, female <18 kg). Risk factors associated with the weak and asymmetric HGS were identified by logistic regression analysis.

RESULTS

Risk factors associated with weak and asymmetric HGS of varying severity differed between the two methods. Both methods identified age and illiteracy as risk factors for weak HGS with 10%-20% asymmetry. Method A also identified speech impediment, stroke, and sleep duration as additional risk factors. Similarly, both methods identified age, illiteracy, primary school education and below, diabetes, and stroke as risk factors for weak HGS and asymmetry over 30.1%. Method B additionally identified a history of falls as a risk factor. However, apart from age, the risk factors for weak HGS with 20.1%-30% asymmetry differed between the two methods-Method A identified kidney disease, while Method B identified illiteracy and asthma.

CONCLUSIONS

The results revealed that risk factors associated with the abnormal HGS in older adults varied based on the methods used to define these conditions.

Association of handgrip strength asymmetry and weakness with functional disability among middle-aged and older adults in China

Background

Little is known about the association of handgrip strength (HGS) asymmetry with functional disability in China. We aimed to examine the individual and combined association of HGS asymmetry and weakness with functional disability among middle-aged and older Chinese adults.

Methods

We included participants aged ≥45 years from two waves of the China Health and Retirement Longitudinal Study (2011 and 2015). HGS weakness was defined as the maximal HGS<28 kg for men and <18 kg for women. HGS asymmetry was measured by dividing the maximal nondominant HGS (kg) by the maximal dominant HGS (kg), with the value <0.90 or >1.10 considered as asymmetry. Functional disability was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL) and was defined as encountering difficulty in completing one or more ADL/IADL tasks. The logistic regression models were used to explore the association between HGS measures and functional disability.

Results

11 950 (mean age 59.2 ± 9.6 years, 47.9% males) and 7540 (mean age 57.5 ± 8.6 years, 50.1% males) participants were included in the cross-sectional and prospective study, respectively. HGS asymmetry and weakness, individually or simultaneously, were associated with an increased prevalence of functional disability. During the four-year follow-up, 1822 (24.2%) participants had incident functional disability. The separate exposure to HGS asymmetry (odds ratio (OR) = 1.18; 95% confidence interval (CI) = 1.05-1.32) or weakness (OR = 1.59; 95% CI = 1.30-1.95) was independently associated with functional disability. For combined associations, those with both weakness and asymmetry showed the greatest risk of new-onset functional disability (OR = 1.91; 95% CI = 1.45-2.52).

Conclusions

HGS asymmetry and weakness were associated with a higher risk of functional disability. Assessing HGS asymmetry together with weakness may help to better identify those at risk of functional disability to enable early interventions.

The accuracy of different calculation methods when identifying handgrip strength asymmetry among middle-aged and older Chinese adults

At present, there is no uniform standard mean of identifying handgrip strength (HGS) asymmetry based on maximum or average HGS values. Therefore, this study aimed to explore the accuracy of different calculation methods in the evaluation of HGS asymmetry. Using the maximum reading of two trials from both hands (Method A) as the reference standard, the accuracy of the HGS asymmetry identified by the average value of two trials of both hands (Method B) was determined by using various indicators, including specificity, sensitivity, the area under the receiver operating characteristic curve (AUC), positive, and negative predictive values. Overall, 12,163 individuals were included in this study, of whom 47.61% (5791/12,163) were male. The percentages of individuals with HGS asymmetry differed as a function of age and sex when using these two different methods. When employing Method A, 38.52%, 41.57%, and 44.57% of males 45 ≤ age<60, 60 ≤ age<80, and ≥ 80 years of age exhibited HGS asymmetry as compared to 40.78%, 39%, and 39.63% of females. Using Method B, the corresponding proportions were 41.69%, 42.5%, and 40% in males and 42.01%, 41.18%, and 40.55% in females, respectively. When compared to Method A, Method B was found to be effective in identifying HGS asymmetry, with AUC values ranging from 0.844 to 0.877. However, there was only moderate agreement between the two methods in assessing HGS asymmetry. Specifically, the Kappa values for the two Methods were 0.692, 0.694, and 0.766 in males aged 45 to 60, 60 to 80, and 80 years and above, respectively. For females, the Kappa values were 0.674, 0.661, and 0.751, respectively. These results demonstrated that the maximal or average HGS values from two trials using both hands has a significant impact on the consequent identification of HGS asymmetry.

Handgrip strength asymmetry and cognitive impairment risk: Insights from a seven-year prospective cohort study

OBJECTIVES

This study aimed to explore the links of handgrip strength and asymmetry with cognitive impairment.

DESIGN

This was a seven-year prospective cohort study.

SETTING AND PARTICIPANTS

We used data from wave 3 (2015-2017) to wave 5 (2019-2022) from the ongoing Taiwan Initiative of Geriatric Epidemiological Research (TIGER), with wave 3 as the baseline (n = 446). The study included community-dwelling participants aged 65 years or older.

MEASUREMENTS

Handgrip strength was measured, and abnormalities were determined based on handgrip strength weakness and asymmetry. Handgrip strength asymmetry was categorized into three groups at baseline based on the handgrip strength ratio (left handgrip strength/right handgrip strength). Cognitive tests evaluating global and specific cognitive domains were conducted at baseline and two biennial follow-ups. Generalized linear mixed models were utilized to assess the associations of abnormal handgrip strength with global cognition and multiple cognitive domain progression over time.

RESULTS

This study included 392 dementia-free participants, with an average age of 75.8 years and 179 (45.7%) males. Mild handgrip strength asymmetry was present in 88 participants (22.4%), while 53 (13.5%) exhibited moderate asymmetry. In men, the coexistence of low handgrip strength and handgrip strength asymmetry was linked to cognitive impairment over time. These associations were observed in global cognition (β^ = -1.76, 95% CI: -2.79 to -0.74), memory (immediate free recall: β^ = -0.67, 95% CI: -1.17 to -0.17), executive function (Trail Making Test-A: β^ = -0.54, 95% CI: -0.94 to -0.13), and attention (Digit span-forward: β^ = -1.00, 95% CI: -1.46 to -0.54).

CONCLUSIONS

This study found that individuals with reduced handgrip strength and handgrip strength asymmetry had an increased risk of cognitive impairment across various domains. Moreover, this association appears to be more pronounced among men than women. Incorporating these simple assessments into regular clinical practice improves the allocation of limited screening resources and timely clinical interventions in older adults.

The relationship between low handgrip strength with or without asymmetry and fall risk among middle-aged and older males in China: evidence from the China Health and Retirement Longitudinal Study

PURPOSE

This study sought to explore the potential correlation between low handgrip strength (HGS) with or without asymmetry and fall risk in middle-aged and older Chinese adults.

METHODS

Baseline characteristic data from participants 45+ years of age and data regarding fall events collected from two rounds (2011-2013) of the China Health and Retirement Longitudinal Study were utilized for the present analyses. HGS and HGS asymmetry was defined according to the updated American Society of Hand Therapist. Fall events were identified through self- or proxy-reported details. Logistic regression analyses were employed to gauge the potential relationship between abnormal HGS and fall risk.

RESULTS

In total, 10 563 participants were enrolled in this analysis, of whom 47.49% (5016/10 563) were male. The proportions of low HGS alone, HGS asymmetry alone, and low HGS with asymmetry were 22.23%, 18.34%, and 22.75%, respectively, in males, but just 3.64%, 35.12%, and 6.62% in females. A total of 693 and 1019 fall events were recorded for male (13.82%) and female (18.37%) participants over the 2-year follow-up period, respectively. Significant differences in fall event incidence among different HGS groups were only observed among males. An adjusted logistic regression analysis model confirmed that low HGS with dominant asymmetry was closely related to fall risk among middle-aged and older males [P = 0.014, odds ratio = 1.332, 95% confidence interval: 1.059-1.676).

CONCLUSION

These results demonstrated that low HGS with dominant asymmetry is a risk factor linked to increased fall risk among middle-aged and older Chinese males. What is already known on this topic Low HGS or HGS asymmetry is been reported to be linked to an increased risk of falls in middle-aged and older adults; however, little is known about the association between fall risk and low HGS and/or HGS asymmetry. Main messages The prevalence of low HGS alone and low HGS asymmetry in men was significantly higher than in women, while HGS alone asymmetry was more common in women than men. The risk factor for the increased risk of falls in Chinese middle-aged and older men is low and asymmetric HGS, rather than low or asymmetric HGS alone. Low HGS with dominant asymmetry rather than nondominant asymmetry is associated with future fall risk among middle-aged and older Chinese males. Current research questions What is the mechanism for the significant difference in the proportion of abnormal HGS components between the sexes? If female subjects with low HGS and asymmetric HGS were added, would an association be observed between low HGS and asymmetric HGS falls? Is there an association between the severity of asymmetric HGS with weakness and falls?

Tracking handgrip strength asymmetry from childhood to mid-life

AIM

Determine if asymmetric handgrip strength exists in childhood and adulthood and quantify the degree of tracking of handgrip strength asymmetry over time.

METHODS

Participants from the Childhood Determinants of Adult Health Study had their right and left handgrip strength measured using handgrip dynamometry in childhood (1985: 9-15 y), young adulthood (2004-06: 26-36 y) and/or mid-adulthood (2014-19: 36-49 y). Handgrip strength asymmetry was calculated as: strongest handgrip strength/strongest handgrip strength on the other hand. Participants were categorised based on the degree of their asymmetry (0.0%-10.0%, 10.1%-20.0%, 20.1%-30.0%, >30.0%). Tracking was quantified using Spearman's correlations and log binomial regression.

RESULTS

Handgrip strength asymmetry was present in childhood and adulthood (>30.0% asymmetry: childhood = 6%, young adulthood = 3%, mid-adulthood = 4%). Handgrip strength asymmetry did not track between childhood and young- (r = 0.06, 95% CI = -0.02, 0.12) and mid-adulthood (r = 0.01, 95% CI = -0.09, 0.10). Tracking was more apparent between young- and mid-adulthood (r = 0.16, 95% CI = 0.09, 0.22). Participants with >30.0% asymmetry were at greater risk to maintain this status between childhood and young- (RR = 3.53, 95% CI = 1.15, 10.87) and mid-adulthood (RR = 2.14, 95% CI = 0.45, 10.20).

CONCLUSION

Although handgrip strength asymmetry tracked relatively poorly, asymmetric handgrip strength was apparent in children and adults. Handgrip strength asymmetry does not exclusively affect older adults and should be considered in protocols to better understand its role across the life course.

Handgrip strength asymmetry as a new biomarker for sarcopenia and individual sarcopenia signatures

BACKGROUND

Although handgrip strength (HGS) asymmetry has clinical screening utility, its relevance to sarcopenia is unknown. This study examined the relationship between HGS asymmetry and sarcopenia signatures, and explored the relevance of circulating neural/neuromuscular markers.

METHODS

9403 individuals aged 18-92 years participated in this study. Maximal HGS and skeletal muscle index (SMI) were determined using hand dynamometry and DXA. Sarcopenia was diagnosed upon the presence of low HGS and low SMI, according to cohort-specific thresholds. Plasma biomarkers were measured by ELISA in a sub-group of 269 participants aged 50-83 years. Asymmetry was determined as the highest recorded HGS divided by the highest recorded HGS of the opposite hand. Individuals with a ratio > 1.10 were classified as having asymmetrical HGS.

RESULTS

Subjects with asymmetrical HGS had significantly lower SMI (7.67 kg/m2 vs 7.71 kg/m2, p = 0.004) and lower HGS (37.82 kg vs 38.91 kg, p < 0.001) than those with symmetrical HGS. In those aged ≥ 50 years asymmetrical HGS was associated with 2.67 higher odds for sarcopenia [95% confidence interval: (CI) = 1.557-4.561, p < 0.001], 1.83 higher odds for low HGS only (CI 1.427-2.342, p < 0.001), and 1.79 higher odds for low SMI only (CI 1.257-2.554, p = 0.001). HGS asymmetry demonstrated acceptable diagnostic accuracy for sarcopenia (AUC = 0.727, CI 0.658-0.796, p < 0.001). Plasma neural cell adhesion molecule concentrations were 19.6% higher in individuals with asymmetrical HGS (185.40 ng/mL vs 155.00 ng/mL, p < 0.001) than those with symmetrical HGS.

DISCUSSION

Our findings demonstrate the utility of HGS asymmetry as a screening tool that may complement existing strategies seeking to combat sarcopenia. Biomarker analyses suggest that heightened denervation may be an important aetiological factor underpinning HGS asymmetry.

Short sleeping duration is associated with a higher risk of asymmetric handgrip strength among older Chinese males: a cross-sectional study evidence from the China health and retirement longitudinal study

Objective

This study aimed to explore the potential correlation between sleeping duration and the risk of handgrip strength (HGS) asymmetry in older Chinese adults.

Methods

The data of participants (65+ years of age) were obtained from the first Wave 1 (2011) of the China Health and Retirement Longitudinal Study (CHARLS). Information on sleeping duration during the previous month was collected from self-reports and was divided into three groups: long (>8 h), normal (6-8 h), and short (< 6 h). HGS was computed as the average of two tests per hand and asymmetric HGS was diagnosed when the ratio of average non-dominant to average dominant HGS was greater than 1.1 or less than 0.9. Logistic regression analyses were employed to gauge the relationship between sleeping duration and asymmetric HGS risk.

Results

In total, 3,174 participants were enrolled in this analysis, of whom 51.54% (1,636/3,174) were male. The proportions of asymmetric HGS were 42.18% in males and 41.87% in females. The sleeping duration (hours) in the asymmetric and non-asymmetric HGS groups were 6 h (5,8) and 7 h (5,8) in males with a significant difference between them (p = 0.015), and 6 h (5,8) and 6 h (5,8) in females with no significant difference (p = 0.415). Compared with non-asymmetric HGS individuals, the proportions of normal, short, and long sleeping duration were 40.4, 47.3, and 37.7% in males with a significant difference (p = 0.023), and 42.4, 40.3, and 43.8% in females with no significant differences (p = 0.685). An adjusted logistic regression analysis model confirmed that short sleeping duration was significantly associated with asymmetric HGS risk among older males (p = 0.048, OR = 1.252, 95%CI:1.002-1.565).

Conclusion

The results demonstrated that short sleeping duration (<6 h) was a risk factor for increased HGS asymmetry among older Chinese males.

Prevalence and Trends of Slow Gait Speed in the United States

Gait speed is a simple, effective indicator of age-related disease and disability. We sought to examine the prevalence and trends of slow gait speed in older Americans. Our unweighted analytic sample included 12,427 adults aged ≥ 65 years from the 2006-2016 waves of the Health and Retirement Study. Gait speed was measured in participant residences. Persons with gait speed < 0.8 or <0.6 m/s were slow. Sample weights were used to generate nationally representative estimates. The overall estimated prevalence of slow gait speed with the <0.8 m/s cut-point was 48.6% (95% confidence interval (CI): 47.4-49.8) in the 2006-2008 waves yet was 45.7% (CI: 44.3-47.1) in the 2014-2016 waves, but this downward trend was not statistically significant (p = 0.06). The estimated prevalence of slowness with the <0.6 m/s cut-point was 21.3% (CI: 20.4-22.3) for the 2006-2008 waves, 18.5% (CI: 17.5-19.4) for the 2010-2012 waves, and 19.2% (CI: 18.2-20.2) for the 2014-2016 waves, but there were again no significant trends (p = 0.61). Our findings showed that the estimated prevalence of slow gait speed in older Americans is pronounced, and different cut-points largely inform how slowness is categorized. Continued surveillance of slowness over time will help guide screening for disablement and identify sub-populations at greatest risk for targeted interventions.

Using Electronic Handgrip Dynamometry and Accelerometry to Examine Multiple Aspects of Handgrip Function in Master Endurance Athletes: A Pilot Study

ABSTRACT

Klawitter, LA, Hackney, KJ, Christensen, BK, Hamm, JM, Hanson, M, and McGrath, R. Using electronic handgrip dynamometry and accelerometry to examine multiple aspects of handgrip function in master endurance athletes: A Pilot Study. J Strength Cond Res 37(9): 1777-1782, 2023-Electronic handgrip dynamometry and accelerometry may provide novel opportunities to comprehensively measure muscle function for human performance, especially for master athletes. This investigation sought to determine the multivariate relationships between maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness to derive one or more handgrip principal components in master-aged endurance athletes. We included n = 31 cyclists and triathletes aged 35-70 years. Maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness were measured twice on each hand using electronic handgrip dynamometry and accelerometry. The highest performing measures were included in the analyses. A principal component analysis was conducted to derive a new collection of uncorrelated variables from the collected handgrip measurements. Principal components with eigenvalues >1.0 were kept, and individual measures with a factor loading of |>0.40| were retained in each principal component. There were 3 principal components retained with eigenvalues of 2.46, 1.31, and 1.17. The first principal component, "robust strength," contained maximal strength, rate of force development, submaximal force control, and neuromuscular steadiness. The second principal component, "bilateral synergy," contained asymmetry and bimanual coordination, whereas the third principal component, "muscle conditioning," contained fatigability. Principal components 1, 2, and 3 explained 44.0, 31.6, and 24.4% of the variance, respectively. Different dimensions of muscle function emerged from our findings, suggesting the potential of a muscle function battery. Further research examining how these measures are associated with appropriate human performance metrics and lower extremity correlates is warranted.

Handgrip Strength Is Associated with Specific Aspects of Vascular Function in Individuals with Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MetS) is a disorder associated with an increased risk for the development of diabetes mellitus and its complications. Lower isometric handgrip strength (HGS) is associated with an increased risk of cardiometabolic diseases. However, the association between HGS and arterial stiffness parameters, which are considered the predictors of morbidity and mortality in individuals with MetS, is not well defined.

OBJECTIVE

To determine the association between HGS and HGS asymmetry on components of vascular function in adults with MetS.

METHODS

We measured handgrip strength normalized to bodyweight (HGS/kg), HGS asymmetry, body composition, blood glucose, lipid profile, blood pressure, pulse wave velocity (PWV), reflection coefficient (RC), augmentation index @75 bpm (AIx@75) and peripheral vascular resistance (PVR) in 55 adults with a diagnosis of MetS between 25 and 54 years old.

RESULTS

Mean age was 43.1 ± 7.0 years, 56.3% were females. HGS/kg was negatively correlated with AIx@75 (r = -0.440), p < 0.05, but these associations were not significant after adjusting for age and sex. However, when interaction effects between sex, HGS/kg and age were examined, we observed an inverse relationship between HGS/kg and AIx@75 in the older adults in the sample, whereas in the younger adults, a weak direct association was found. We also found a significant association between HGS asymmetry and PVR (beta = 30, 95% CI = 7.02; 54.2; p <0.012).

CONCLUSIONS

Our findings suggest that in people with MetS, maintaining muscle strength may have an increasingly important role in older age in the attenuation of age-related increases in AIx@75-a marker of vascular stiffness-and that a higher HGS asymmetry could be associated with a greater vascular resistance.

Prevalence and Trends of Handgrip Strength Asymmetry in the United States

Background

Strength asymmetries are a type of muscle function impairment that is associated with several health conditions. However, the prevalence of these asymmetries among adults from the United States remains unknown. We sought to estimate the prevalence and trends of handgrip strength (HGS) asymmetry in American adults.

Methods

The unweighted analytic sample included 23,056 persons aged at least 50-years with information on HGS for both hands from the 2006-2016 waves of the Health and Retirement Study. A handgrip dynamometer measured HGS, with the highest recorded values for each hand used to calculate asymmetry. Persons were categorized into the following asymmetry severity categories: (1) >10%, (2) >20.0%, and (3) >30.0%. Survey weights were used to generate nationally-representative asymmetry estimates.

Results

Overall, there were no statistically significant trends in HGS asymmetry categories over time. The prevalence of HGS asymmetry in the 2014-2016 wave was 53.4% (CI: 52.2-54.4), 26.0% (CI: 25.0-26.9), and 11.7% (CI: 10.9-12.3) for asymmetry at >10%, >20%, and >30%, respectively. HGS asymmetry was generally higher in older Americans compared to middle-aged adults at each wave. In the 2014-2016 wave, >30% asymmetry prevalence was 13.7% (CI: 12.7-14.6) in females and 9.3% (CI: 8.4-10.2) in males. Some differences in asymmetry prevalence by race and ethnicity were observed.

Conclusions

The prevalence of asymmetry was generally high, especially in women and older adults. Ongoing surveillance of strength asymmetry will help monitor trends in muscle dysfunction, guide screening for disablement, identify subpopulations at risk for asymmetry, and inform relevant interventions.

The Associations of Pulse Pressure and Mean Arterial Pressure on Physical Function in Older Americans

Background: We sought to examine the associations of pulse pressure (PP) and mean arterial pressure (MAP) on physical function in older Americans. Methods: Our analytic sample included 10,478 adults aged ≥65 years from the 2006–2016 Health and Retirement Study. Handgrip strength, gait speed, and standing balance were collected using relatively standard protocols. PP and MAP were calculated from blood pressure measurements. Results: Older Americans with any abnormality in PP had 1.15 (95% confidence interval (CI): 1.05–1.25) greater odds for slowness and 1.14 (CI: 1.05–1.24) greater odds for poorer standing balance. Persons with any abnormality in MAP had 0.90 (CI: 0.82–0.98) decreased odds for weakness and 1.10 (CI: 1.01–1.20) greater odds for poorer standing balance. Those with low PP had 1.19 (CI: 1.03–1.36) greater odds for slow gait speed, while persons with low MAP had 1.50 (CI: 1.09–2.05) greater odds for weakness and 1.45 (CI: 1.03–2.04) greater odds for slowness. Older Americans with high PP had 1.13 (CI: 1.03–1.25) greater odds for slowness and 1.21 (CI: 1.10–1.32) greater odds for poorer balance, whereas those with high MAP had 0.87 (CI: 0.80–0.95) decreased odds for weakness. Conclusions: Cardiovascular dysfunction, as observed by PP and MAP, may help to explain some of our findings.

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.

Undiagnosed Dementia Is Associated with Poor Physical Function in Older Adults

BACKGROUND

Older adults with a cognitive impairment, including those not yet diagnosed, may have deficits in their physical function.

OBJECTIVE

We sought to determine the associations of cognitive impairment consistent with dementia (CICD) diagnosis status on handgrip strength, gait speed, and functional disability in older adults.

METHODS

The analytical sample included 8,383 adults aged ≥65-years without history of stroke, cancers, neurological conditions, or brain damage who participated in at least one-wave of the 2010-2016 waves of the Health and Retirement Study. A handgrip dynamometer measured handgrip strength. Men with handgrip strength <26 kg and women <16 kg were weak. Gait speed was timed across a 2.5-m course and those with slowness had gait speed <0.8 m/s. Participants with difficulty or an inability in completing any basic activities of daily living had a functional disability. The adapted Telephone Interview of Cognitive Status evaluated cognitive function. Persons with scores <7 had a CICD. Healthcare provider dementia-related diagnosis was self-reported. Undiagnosed CICD was defined as no reported dementia-related diagnosis but had CICD, while diagnosed CICD was classified as reporting a dementia-related diagnosis. Covariate-adjusted logistic models were used for the analyses.

RESULTS

Persons with undiagnosed CICD had 1.37 (95% confidence interval (CI): 1.04-1.80) greater odds for weakness and 2.02 (CI: 1.39-2.94) greater odds for slow gait speed. Older adults with diagnosed CICD had 2.29 (CI: 1.32-3.97) greater odds for slowness and 1.85 (CI: 1.19-2.90) greater odds for functional disability.

CONCLUSION

Screening for CICD could be recommended when defects in physical function are observed in older adults.