Association of Handgrip Strength and Cardiovascular Disease Risk Among Middle-Aged Postmenopausal Women: An Analysis of the Korea National Health and Nutrition Examination Survey 2014-2019.

Purpose: Handgrip strength is an indicator of overall muscle strength and has been associated with an increased risk of cardiovascular disease. Evidence suggests that menopause is a risk factor for cardiovascular disease in women, and muscle strength decreases progressively after menopause. Despite the prognostic importance of the decline in muscle strength and increased cardiovascular disease risk among postmenopausal women, evidence of their association is limited. This study aimed to investigate the relationship between handgrip strength and cardiovascular disease risk among postmenopausal, middle-aged Korean women. Patients and Methods: Using pooled cohort equations, we calculated the 10-year risk of atherosclerotic cardiovascular disease (ASCVD) among postmenopausal women (N = 2019) aged 50-64 years without cardiovascular disease history from the 2014-2019 Korea National Health and Nutrition Examination Survey. Relative grip strength was defined as measured grip strength divided by body mass index. Logistic regression analysis of a complex sampling design was performed to evaluate the association between relative grip strength and a predicted 10-year ASCVD risk ≥7.5%. Results: The average handgrip strength was 24.8 kg, and 5.2% of women were considered for sarcopenia (<18 kg). The quartile-stratified relative grip strength was negatively associated with 10-year ASCVD risk (p < 0.001). In the multiple logistic regression analysis, the adjusted odds ratio for the highest relative grip strength quartile was 0.53 (95% confidence interval [CI]: 0.36-0.78), and that of the group who breastfed for more than 12 months was 1.75 (95% CI: 1.36-2.25) for 10-year ASCVD risk. Conclusion: Increased handgrip strength may be associated with lower cardiovascular disease risk among middle-aged postmenopausal women in Korea. Our findings provide critical evidence regarding the importance of increasing handgrip strength among postmenopausal, middle-aged women to reduce cardiovascular disease risk. Handgrip strength measurement might be a valuable screening tool for cardiovascular disease prevention.

Postmenopausal women with higher TSH values within the normal range present improved handgrip strength: a pilot study.

OBJECTIVE: To evaluate the possible association between thyroid function within the euthyroid range and musculoskeletal parameters as well as body composition in a sample of postmenopausal women. METHODS: This cross-sectional study included 96 postmenopausal women with serum thyroid-stimulating hormone (TSH) within the normal laboratory reference range. Fasting venous blood samples were obtained for biochemical/hormonal assessment. Bone status and body composition were measured using Dual Energy X-ray absorptiometry (DXA). Physical activity was quantified using the International Physical Activity Questionnaire (IPAQ) index. RESULTS: Serum TSH correlated with handgrip strength (HGS, r-coefficient = 0.233, p = .025), and total body bone mineral density (BMD) T-score values (r-coefficient = 0.321, p = .003). HGS measures were associated with BMD (r-coefficient = 0.415, p < .001), with bone mineral content (BMC, r-coefficient = 0.427, p < .001), and lean mass (r-coefficient = 0.326, p = .003). Women with low muscle strength, defined as HGS < 16 kg, had lower TSH levels than women with normal muscle strength (low vs. normal muscle strength, ANCOVA 1.13 ± 0.49 mU/L vs. 1.60 ± 0.83 mU/L, p = 0.024) independently of age, BMD, percentage of body fat or absolute lean mass. Multivariable linear regression analysis showed that HGS values were associated with TSH measurements (ß-coefficient = 0.246, p = .014) and BMD T-score values (ß-coefficient = 0.306, p = .002). All models were adjusted for age, body mass index (BMI), vitamin D, low-density lipoprotein cholesterol, current smoking, physical activity, and homeostasis model assessment of insulin resistance. CONCLUSIONS: In this sample of postmenopausal women, lower serum TSH values, within normal range, were associated with lower muscle strength compared to higher normal TSH values. Further research is needed to elucidate the significance of our preliminary findings.

Sarcopenia and sarcopenic obesity among community-dwelling Peruvian adults: A cross-sectional study.

INTRODUCTION: Sarcopenia and sarcopenic obesity (SO) have emerged as significant contributors to negative health outcomes in the past decade. We aimed to estimate the prevalence of probable sarcopenia, sarcopenia, and SO in a community-dwelling population of 1151 adults aged ≥55 years in Lima, Peru. METHODS: This cross-sectional study was conducted between 2018 and 2020. Sarcopenia was defined as the presence of low muscle strength (LMS) and low muscle mass (LMM) according to European (EWGSOP2), US (FNIH) and Asian (AWGS2) guidelines. We measured muscle strength by maximum handgrip strength and muscle mass using bioelectrical impedance analyzer. SO was defined as a body mass index ≥ 30 kg/m2 and sarcopenia. RESULTS: The study participants had a mean age of 66.2 years (SD 7.1), age range between 60 to 92 years old, of which 621 (53.9%) were men. Among the sample, 41.7% were classified as obese (BMI ≥30.0 kg/m²). The prevalence of probable sarcopenia was estimated to be 22.7% (95%CI: 20.3-25.1) using the EWGSOP2 criteria and 27.8% (95%CI: 25.2-30.4) using the AWGS2 criteria. Sarcopenia prevalence, assessed using skeletal muscle index (SMI), was 5.7% (95%CI: 4.4-7.1) according to EWGSOP2 and 8.3% (95%CI: 6.7-9.9) using AWGS2 criteria. The prevalence of sarcopenia based on the FNIH criteria was 18.1% (95%CI: 15.8-20.3). The prevalence of SO, considering different sarcopenia definitions, ranged from 0.8% (95%CI: 0.3-1.3) to 5.0% (95%CI: 3.8-6.3). CONCLUSION: Our findings reveal substantial variation in the prevalence of sarcopenia and SO, underscoring the necessity for context-specific cut-off values. Although the prevalence of SO was relatively low, this result may be underestimated. Furthermore, the consistently high proportion of probable sarcopenia and sarcopenia point to a substantial public health burden.

Carpal tunnel syndrome prediction with machine learning algorithms using anthropometric and strength-based measurement.

OBJECTIVES: Carpal tunnel syndrome (CTS) stands as the most prevalent upper extremity entrapment neuropathy, with a multifaceted etiology encompassing various risk factors. This study aimed to investigate whether anthropometric measurements of the hand, grip strength, and pinch strength could serve as predictive indicators for CTS through machine learning techniques. METHODS: Enrollment encompassed patients exhibiting CTS symptoms (n = 56) and asymptomatic healthy controls (n = 56), with confirmation via electrophysiological assessments. Anthropometric measurements of the hand were obtained using a digital caliper, grip strength was gauged via a digital handgrip dynamometer, and pinch strengths were assessed using a pinchmeter. A comprehensive analysis was conducted employing four most common and effective machine learning algorithms, integrating thorough parameter tuning and cross-validation procedures. Additionally, the outcomes of variable importance were presented. RESULTS: Among the diverse algorithms, Random Forests (accuracy of 89.474%, F1-score of 0.905, and kappa value of 0.789) and XGBoost (accuracy of 86.842%, F1-score of 0.878, and kappa value of 0.736) emerged as the top-performing choices based on distinct classification metrics. In addition, using variable importance calculations specific to these models, the most important variables were found to be wrist circumference, hand width, hand grip strength, tip pinch, key pinch, and middle finger length. CONCLUSION: The findings of this study demonstrated that wrist circumference, hand width, hand grip strength, tip pinch, key pinch, and middle finger length can be utilized as reliable indicators of CTS. Also, the model developed herein, along with the identified crucial variables, could serve as an informative guide for healthcare professionals, enhancing precision and efficacy in CTS prediction.

Deficits in force production during multifinger tasks demarcate cognitive dysfunction.

BACKGROUND: The multifinger force deficit (MFFD) is the decline in force generated by each finger as the number of fingers contributing to an action is increased. It has been shown to associate with cognitive status. AIMS: The aim was to establish whether a particularly challenging form of multifinger grip dynamometry, that provides minimal tactile feedback via cutaneous receptors and requires active compensation for reaction forces, will yield an MFFD that is more sensitive to cognitive status. METHODS: Associations between measures of motor function, and cognitive status (Montreal Cognitive Assessment [MoCA]) and latent components of cognitive function (derived from 11 tests using principal component analysis), were estimated cross-sectionally using generalized partial rank correlations. The participants (n = 62) were community dwelling, aged 65-87. RESULTS: Approximately half the participants were unable to complete the dynamometry task successfully. Cognitive status demarcated individuals who could perform the task from those who could not. Among those who complied with the task requirements, the MFFD was negatively correlated with MoCA scores-those with the highest MoCA scores tended to exhibit the smallest deficits, and vice versa. There were corresponding associations with latent components of cognitive function. DISCUSSION: The results support the view that neurodegenerative processes that are a feature of normal and pathological aging exert corresponding effects on expressions of motor coordination-in multifinger tasks, and cognitive sufficiency, due to their dependence on shared neural systems. CONCLUSIONS: The outcomes add weight to the assertion that deficits in force production during multifinger tasks are sensitive to cognitive dysfunction.

Serum FT3/FT4, but not TSH is associated with handgrip strength in euthyroid U.S. population: evidence from NHANES.

Objective: Although several studies have examined the relationship between thyroid function and muscle strength, their population primarily derived from Asian areas, and their results were controversial. Thus, this study aimed to explore the association between thyroid function and handgrip strength (HGS) in the U.S. population. Methods: A total of 1,067 participants from NHANES were categorized into three different age groups including young (<45 years), middle (45~64 years), and old (≥65 years) age groups. Thyroid function was measured by the competitive binding immune-enzymatic assays, while HGS was examined by a trained evaluator using a dynamometer. The weighted multiple linear regression models were used to examine the association between thyroid function and handgrip strength. The restricted cubic splines were employed to explore the non-linear relationship between these two variables. All statistical analyses were performed using the SPSS version 20.0 and R software. Results: After adjustment for potential covariates, FT3/FT4, but not TSH was positively associated with HGS in middle age group (ß=0.091, t=2.428, P=0.016). The subgroup analysis by sex revealed that the positive association between FT3/FT4 and HGS was observed in the middle age group for both male and female participants (ß=0.163, t=2.121, P=0.035; ß=0.157, t=2.180, P=0.031). The RCS analysis showed a statistically significant non-linear association between FT3/FT4 and HGS in overall population (P for non-linear=0.026). After adjustment for covariates, men with low HGS had a significant lower FT3/FT4 than those without low HGS in old age group (P=0.013). There was a significant increase in TSH level for female participants with low HGS in old age group compared to those with normal HGS (P=0.048). Conclusions: This study demonstrated FT3/FT4, but not TSH, was positively associated with HGS in middle age group, and the different association was observed in men in middle age group when participants were stratified by sex. Future longitudinal cohort study should be conducted to reveal the causal relationship between thyroid function and muscle strength.

Relationship between Eating Alone and Handgrip Strength in Korean Older Adults.

Sarcopenia is defined as an age-related decline in muscle mass, muscle strength, and physical performance. Eating alone has been linked to various health issues in older adults. This study investigated the relationship between eating alone and handgrip strength (HGS) in older adults using data from 7278 individuals (≥65 years) who participated in the 2014-2019 Korea National Health and Nutrition Examination Survey. HGS was measured using a digital grip strength dynamometer, relative HGS was calculated by dividing HGS by body mass index, and dynapenia was defined as an HGS < 28 kg for men and <18 kg for women. Multivariable logistic regression analysis showed that women who ate two meals alone were more likely to exhibit dynapenia than those who never ate alone (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.03-1.77). If the groups that never ate alone or ate one meal alone were combined as the reference group, the probability of dynapenia was higher in the combined groups that ate two or three meals alone (OR, 1.25; 95% CI, 1.04-1.50). No association was observed between eating alone and dynapenia in men. This suggests that eating alone is a modifiable related factor of dynapenia in older women.

Variability between Different Hand-Held Dynamometers for Measuring Muscle Strength.

Muscle strength is routinely measured in patients with neuromuscular disorders by hand-held dynamometry incorporating a wireless load cell to evaluate disease severity and therapeutic efficacy, with magnitude of effect often based on normative reference values. While several hand-held dynamometers exist, their interchangeability is unknown which limits the utility of normative data. We investigated the variability between six commercially available dynamometers for measuring the isometric muscle strength of four muscle groups in thirty healthy individuals. Following electro-mechanical sensor calibration against knowns loads, Citec, Nicholas, MicroFET2, and Commander dynamometers were used to assess the strength of ankle dorsiflexors, hip internal rotators, and shoulder external rotators. Citec, Jamar Plus, and Baseline Hydraulic dynamometers were used to capture hand grip strength. Variability between dynamometers was represented as percent differences and statistical significance was calculated with one-way repeated measures ANOVA. Percent differences between dynamometers ranged from 0.2% to 16%. No significant differences were recorded between the Citec, Nicholas, and MicroFET2 dynamometers (p > 0.05). Citec grip strength measures differed to the Jamar Plus and Baseline Hydraulic dynamometers (p < 0.01). However, when controlling for grip circumference, they were comparable (p > 0.05). Several hand-held dynamometers can be used interchangeably to measure upper and lower limb strength, thereby maximising the use of normative reference values.

The choice of diagnostic modality influences the proportion of low muscle strength, low muscle mass, and sarcopenia in colorectal cancer patients.

BACKGROUND AND AIMS: Low muscle strength, low muscle mass, and sarcopenia have a negative impact on health outcomes in colorectal cancer (CRC) patients. Different diagnostic modalities are used to identify these conditions but it is unknown how well the modalities agree. The aim of this study was to compare different diagnostic modalities by means of calculating the proportion of low muscle strength, low muscle mass, and sarcopenia in CRC patients, and to investigate the agreement for sarcopenia between the various modalities. METHODS: Men and women participating in the Norwegian Dietary Guidelines and colorectal cancer Survival (CRC-NORDIET) study were included in the analyses. Cut-off values for low muscle strength, low muscle mass, and sarcopenia were defined according to the second consensus set by the European Working Group on Sarcopenia in Older People (EWGSOP2). The diagnostic modalities used to assess muscle strength were handgrip strength and the sit-to-stand test. For muscle mass, computed tomography, dual-energy X-ray absorptiometry (DXA), multi-frequency bioelectrical impedance analysis (MF-BIA), and single-frequency BIA (SF-BIA) were applied. Cohen's kappa was calculated to determine the agreement for low muscle strength and confirmed sarcopenia between diagnostic modalities. RESULTS: Five hundred and three men and women (54 % men, mean age of 66 (range 50-80) years old) were included in the analysis. As much as 99 % (n = 70) of the population was identified with low muscle mass by MF-BIA, while the other modalities identified 9-49 % as having low muscle mass. Handgrip strength identified a lower proportion of low muscle strength as compared with the sit-to-stand test (4 % vs. 8 %). When applying various combinations of diagnostic modalities for low muscle strength and low muscle mass, the proportion of sarcopenia was found to be between 0.3 and 11.4 %. There was relatively poor agreement between the different diagnostic modalities with Cohen's Kappa ranging from 0.0 to 0.55, except for the agreement between SF-BIASergi and MF-BIASergi, which was 1. CONCLUSION: The proportion of low muscle strength, low muscle mass, and sarcopenia in CRC patients varied considerably depending on the diagnostic modalities used. Further studies are needed to provide modality-specific cut-off values, adjusted to sex, age and body size.

Pain Characteristics and Progression to Sarcopenia in Chinese Middle-Aged and Older Adults: A 4-Year Longitudinal Study.

BACKGROUND: It is imperative for public health to identify the factors that contribute to the progression of sarcopenia among middle-aged and older adults. Our study aimed to investigate the association between pain characteristics and the progression to sarcopenia and its subcomponents among middle-aged and older adults in China. METHODS: We included 5 568 participants from the China Health and Retirement Longitudinal Study. All participants completed assessments for pain characteristics and sarcopenia. Pain assessment included pain status (baseline pain, incident pain, and pain persistence) and pain distribution (single-site pain and multisite pain) using a self-report questionnaire. Diagnosis of sarcopenia followed The Asian Working Group for Sarcopenia 2019 consensus. The odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by logical regression analysis. RESULTS: Participants who reported baseline pain, multisite pain, pain persistence, or multisite pain persistence were more likely to progress to sarcopenia than those without pain, with ORs of 1.33 (95% CI: 1.08-1.65), 1.44 (95% CI: 1.15-1.80), 1.63 (95% CI: 1.23-2.14), and 1.59 (95% CI: 1.19-2.11), respectively. Even after adjusting for other covariates such as gender, age, residential area, education level, marital status, smoking, alcohol consumption, comorbidities, and falls, these associations remained significant. Additionally, pain persistence and multisite pain persistence were significantly associated with low grip strength and clinically meaningful Short Physical Performance Battery decline, but not with low muscle mass. CONCLUSIONS: Our study showed that pain, especially pain persistence, was closely correlated to the increased risk of progression to sarcopenia in Chinese middle-aged and older adults.

Assessment of sarcopenic obesity as a predictor of pneumonia in patients with stable schizophrenia-A prospective study.

OBJECTIVE: The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) recently released the first international consensus on the diagnostic criteria for Sarcopenic obesity (SO). The present study aimed to explore the ability of SO to predict the risk of pneumonia in patients with stable schizophrenia. METHODS: This was a prospective study involving hospitalized patients with schizophrenia aged ≥50 years from two mental health centers in western China. Baseline patient data were collected from September 1 to September 30, 2020. Follow-up data on pneumonia were collected from October 2020 to October 2022. The diagnosis of SO was based on the ESPEN/EASO criteria. Patients were assessed for handgrip strength (HGS), skeletal muscle mass/weight (SMM/W), and fat mass percentage (FM%). Logistic regression analysis was used to explore the effect of SO on the risk of pneumonia in patients with stable schizophrenia. RESULTS: A total of 320 patients with stable schizophrenia were included. Of these, 74 (23.13%) were diagnosed with SO, while 117 (36.56%) developed pneumonia. Compared with patients in the non-low HGS, non-low HGS + non-low SMM/W (or non-low HGS + low SMM/W or low HGS + non-low SMM/W) and non-SO groups, the proportions of patients with pneumonia in the low HGS (42.3% vs. 25.9%, p = 0.004), low HGS + low SMM/W (45.3% vs. 33.3%, p = 0.048), and SO (47.3% vs. 33.3%, p = 0.029) groups, respectively, were higher. However, there was no difference in the proportion of patients with pneumonia in the low SMM/W group and the obese group compared with the non-low SMM/W and non-obese groups. Further logistic regression analysis after adjustment for potential influencing factors showed that compared with the non-low HGS group, patients in the low HGS group had a higher risk of pneumonia (OR = 1.892, 95%CI: 1.096-3.264). CONCLUSION: SO defined according to the ESPEN/EASO criteria was not found to be significantly associated with the development of pneumonia in patients with stable schizophrenia. Further verification of these results is needed with larger sample sizes and the establishment of a cutoff value for this population.

Could BIA-derived phase angle predict health-related musculoskeletal fitness? A cross-sectional study in young adults.

OBJECTIVES: To our knowledge, little evidence exists on the relationships between body composition and health-related physical fitness; in particular, musculoskeletal fitness. Bioimpedance index phase angle (bioelectrical impedance analysis raw variables) is a candidate predictor of health-related fitness, a marker of fat-free and body cell mass, respectively. The aim of this study was to evaluate body composition, raw bioelectrical impedance analysis variables, and health-related fitness in young adults and investigate their mutual relationships to identify predictors of muscle strength. METHODS: The study included 229 young adults (115 men and 114 women; 24.2 ± 3 y; body mass index 19-30 kg/m²). Anthropometry was measured with standardized procedures. Whole-body BIA (50 kHz) was performed for impedance and phase angle. Predictive equations estimated fat-free mass and percentage body fat. The bioimpedance index was calculated as stature²/impedance. Musculoskeletal fitness was assessed by handgrip strength, standing broad jump, squat jump, and countermovement jump. RESULTS: In both sexes, health-related fitness had stronger associations with body composition than stature or weight. Handgrip strength was related to fat-free mass and bioimpedance index, while an inverse association with percent body fat emerged for standing broad jump, squat jump and countermovement jump. Phase angle is directly correlated with handgrip strength, standing broad jump, squat jump, and countermovement jump. In multiple regression analysis phase angle was an independent predictor of all health-related fitness tests, along with fat-free mass (or bioimpedance index) for handgrip strength, and with sex and percent body fat for the three jump tests. CONCLUSIONS: The present study provided consistent information on the relationships between body composition and health-related fitness in young adults. Phase angle emerged as a significant predictor of all health-related fitness measures and might be useful for a more consistent assessment of musculoskeletal fitness.

Relationship between exercise habits and physical function in children aged 9-12 years.

Exercise improves physical health and positively impacts physical functions in children. Additionally, the habitual exercise established during childhood often continues into adulthood. Therefore, childhood is an important period for establishing healthy habits. Investigating the relationship between the presence or absence of daily exercise and physical functions may provide important information to confirm poor physical function in children with poor exercise habits. Therefore, this study examined the relationship between exercise habits as defined by the Japanese Ministry of Health, Labor, and Welfare and physical function in children aged 9-12 years. Approximately 239 children were included in this study. Participants answered a questionnaire about their exercise habits. We evaluated the skeletal muscle mass index, grip strength, standing broad jump, one-leg standing time, and gait deviation index. Logistic regression analyses were performed to assess exercise habit association with skeletal muscle mass index, physical function, and gait deviation index after adjusting for sex. Of the 239 children, 75.5% (n = 178) had exercise habits. A significant association was noted between exercise habits and skeletal muscle mass index and standing broad jump (skeletal muscle mass index: OR, 1.84; 95% CI, 1.01-3.36 and p<0.05; standing long jump: OR, 1.02; 95% CI, 1.00-1.04 and p<0.05). In conclusion, exercise regardless of exercise level for at least 30 min per day, 2 days per week, for at least 1 year is important for skeletal muscle mass and instantaneous lower limb muscular strength development in school-aged children.

Prevalence and impact of sarcopenia in individuals with heart failure with reduced ejection fraction (the SARC-HF study): A prospective observational study protocol.

Sarcopenia, a clinical syndrome primarily associated with reduced muscle mass in the elderly, has a negative impact on quality of life and survival. It can occur secondarily to other diseases such as heart failure (HF), a complex clinical syndrome with high morbidity and mortality. The simultaneous occurrence of these two conditions can worsen the prognosis of their carriers, especially in the most severe cases of HF, as in patients with reduced left ventricular ejection fraction (LVEF). However, due to the heterogeneous diagnostic criteria for sarcopenia, estimates of its prevalence present a wide variation, leading to new criteria having been recently proposed for its diagnosis, emphasizing muscle strength and function rather than skeletal muscle mass. The primary objective of this study is to evaluate the prevalence of sarcopenia and/or dynapenia in individuals with HF with reduced LVEF according to the most recent criteria, and compare the gene and protein expression of those patients with and without sarcopenia. The secondary objectives are to evaluate the association of sarcopenia and/or dynapenia with the risk of clinical events and death, quality of life, cardiorespiratory capacity, ventilatory efficiency, and respiratory muscle strength. The participants will answer questionnaires to evaluate sarcopenia and quality of life, and will undergo the following tests: handgrip strength, gait speed, dual-energy X-ray absorptiometry, respiratory muscle strength, cardiopulmonary exercise, as well as genomic and proteomic analysis, and dosage of N-terminal pro-B-type natriuretic peptide and growth differentiation factor-15. An association between sarcopenia and/or dynapenia with unfavorable clinical evolution is expected to be found, in addition to reduced quality of life, cardiorespiratory capacity, ventilatory efficiency, and respiratory muscle strength.

[Association between vitamin D level and grip strength in adults aged 50 and older in Shanghai].

Objective: To understand the association between vitamin D level and grip strength in people aged ≥50 years in Shanghai. Methods: Data were obtained from the WHO's Study on Global Ageing and Adult Health in Shanghai during 2018-2019. Logistic regression model was used to analyze the association between vitamin D level and grip strength, and a stratified analysis was conducted for different gender, age and dairy product intake groups. Restricted cubic spline was used to evaluate the dose-response association between vitamin D level and low grip strength. Results: A total of 4 391 participants were included in the study, including 2 054 men (46.8%), with an average age of (67.02±8.81) years. And 1 421 individuals (32.4%) had low grip strength; 1 533 individuals (34.9%) had vitamin D deficiency, and 401 individuals (9.1%) had vitamin D deficiency. After adjusted for confounding factors, the logistic regression results analysis showed that individuals with vitamin D deficiency had a higher risk for low grip strength (OR=1.41, 95%CI: 1.09-1.83). In men, after adjusting for confounding factors, vitamin D deficiency was positively associated with the risk for low grip strength (OR=1.67, 95%CI: 1.12-2.50), but there was no significant association between vitamin D level and grip strength in women (OR=1.30, 95%CI: 0.97-1.74). In age group 60-69 years and ≥80 years, there was significant association between vitamin D deficiency and low grip strength after adjusting for confounding factors (OR=1.57, 95%CI: 1.05-2.35; OR=2.40, 95%CI: 1.08-5.31). In people who had daily intake of dairy product <250 ml, there was positive association between vitamin D deficiency and low grip strength, but there was no significant association in people who had daily dairy product ≥250 ml after adjusting for confounding factors. The restrictive cubic spline demonstrated that risk of low grip strength might decreased with the increase of vitamin D levels, however, the difference was not significant (P>0.05). Conclusions: This study demonstrated that there is association between vitamin D level and grip strength. People with vitamin D deficiency have higher risk for low grip strength.

Advanced liver fibrosis is associated with decreased gait speed in older patients with chronic liver disease.

This study investigated whether the progression of liver fibrosis affects the prevalence of sarcopenia and incidence of decreased gait speed in older patients with chronic liver disease (CLD). Patients with CLD aged ≥ 60 years were classified into low, intermediate, and high fibrosis 4 (FIB-4) index groups according to the degree of liver fibrosis. The prevalence of sarcopenia and incidence of decreased gait speed (< 1.0 m/s) were compared among the three groups. Logistic regression analysis was performed to investigate factors affecting the risk of decreased gait speed. No significant difference was observed in the prevalence of sarcopenia among the three groups, but the incidence of decreased gait speed significantly differed (p = 0.029). When analyzed individually, a significant difference in decreased gait speed incidence was observed between the high and low FIB-4 index groups (p = 0.014). In logistic regression analysis, the progression of liver fibrosis (odds ratio: 1.32, 95% confidence interval: 1.13-1.55) and lower extremity muscle strength (LEMS) (odds ratio: 0.92, 95% confidence interval: 0.88-0.97) were significantly associated with decreased gait speed. As liver fibrosis progresses in older patients with CLD, it becomes important to focus on not only skeletal muscle mass and grip strength, but also gait speed and LEMS.

Sarcopenia in subjects with Alzheimer's disease: prevalence and comparison of agreement between EGWSOP1, EGWSOP2, and FNIH criteria.

BACKGROUND: Sarcopenia is an age-related clinical syndrome characterized by the progressive loss of muscle mass and muscle strength. It appears to be closely linked to dementia, particularly Alzheimer's disease (AD); however, its prevalence among AD patients remains unclear. In this study, we assessed differences in sarcopenia prevalence between non-demented individuals and AD patients. Moreover, we assessed sex-specific differences in sarcopenia prevalence and explored the diagnostic value of the Muscle Quality Index (MQI) for diagnosing sarcopenia among AD patients. METHOD: Cross-sectional study including 145 patients with probable AD and 51 older adults with normal cognition. Sarcopenia was diagnosed according to the criteria of the European Working Group on Sarcopenia in Older People (EWGSOP1 and EWGSOP2) and of the Foundation for the National Institutes of Health (FNIH). The MQI was computed as the ratio of handgrip strength to skeletal muscle mass. RESULTS: No significant difference in sarcopenia prevalence was observed between AD patients and controls. Prevalence ranged from 3.4 to 23.4% in AD patients and from 2 to 11.8% in controls, depending on diagnostic criteria. Prevalence was higher using EWGSOP1 and decreased using EWGSOP2 and FNIH. Prevalence was higher in males than in females with AD. The MQI was lower in AD patients than in controls (95%CI: - 0.23, - 0.05, p < 0.001), but displayed poor diagnostic accuracy in identifying sarcopenia cases. CONCLUSIONS: AD patients and controls show comparable sarcopenia prevalence. Sarcopenia prevalence is higher in males than females among AD patients and higher when using EWGSOP1 compared to FNIH and EWGSOP2 criteria.

i-MYO: A multi-grasp prosthetic hand control system based on gaze movements, augmented reality, and myoelectric signals.

BACKGROUND: Controlling a multi-grasp prosthetic hand still remains a challenge. This study explores the influence of merging gaze movements and augmented reality in bionics on improving prosthetic hand control. METHODS: A control system based on gaze movements, augmented reality, and myoelectric signals (i-MYO) was proposed. In the i-MYO, the GazeButton was introduced into the controller to detect the grasp-type intention from the eye-tracking signals, and the proportional velocity scheme based on the i-MYO was used to control hand movement. RESULTS: The able-bodied subjects with no prior training successfully transferred objects in 91.6% of the cases and switched the optimal grasp types in 97.5%. The patient could successfully trigger the EMG to control the hand holding the objects in 98.7% of trials in around 3.2 s and spend around 1.3 s switching the optimal grasp types in 99.2% of trials. CONCLUSIONS: Merging gaze movements and augmented reality in bionics can widen the control bandwidth of prosthetic hand. With the help of i-MYO, the subjects can control a prosthetic hand using six grasp types if they can manipulate two muscle signals and gaze movement.

Convolutional neural networks reveal properties of reach-to-grasp encoding in posterior parietal cortex.

Deep neural networks (DNNs) are widely adopted to decode motor states from both non-invasively and invasively recorded neural signals, e.g., for realizing brain-computer interfaces. However, the neurophysiological interpretation of how DNNs make the decision based on the input neural activity is limitedly addressed, especially when applied to invasively recorded data. This reduces decoder reliability and transparency, and prevents the exploitation of decoders to better comprehend motor neural encoding. Here, we adopted an explainable artificial intelligence approach - based on a convolutional neural network and an explanation technique - to reveal spatial and temporal neural properties of reach-to-grasping from single-neuron recordings of the posterior parietal area V6A. The network was able to accurately decode 5 different grip types, and the explanation technique automatically identified the cells and temporal samples that most influenced the network prediction. Grip encoding in V6A neurons already started at movement preparation, peaking during movement execution. A difference was found within V6A: dorsal V6A neurons progressively encoded more for increasingly advanced grips, while ventral V6A neurons for increasingly rudimentary grips, with both subareas following a linear trend between the amount of grip encoding and the level of grip skills. By revealing the elements of the neural activity most relevant for each grip with no a priori assumptions, our approach supports and advances current knowledge about reach-to-grasp encoding in V6A, and it may represent a general tool able to investigate neural correlates of motor or cognitive tasks (e.g., attention and memory tasks) from single-neuron recordings.

Longitudinal association of sleep duration with possible sarcopenia: evidence from CHARLS.

OBJECTIVES: There are limited data on the relationship between sleep duration and possible sarcopenia. Hence, this study aimed to investigate the associations of sleep duration with possible sarcopenia and its defining components based on the China Health and Retirement Longitudinal Study (CHARLS). DESIGN: A retrospective cohort study. SETTING: This study was conducted on participants aged over 45 years applying the 2011 baseline and 2015 follow-up survey from CHARLS covering 450 villages, 150 counties and 28 provinces. PARTICIPANTS: Data from 5036 individuals (2568 men and 2468 women) free of possible sarcopenia at baseline were analysed. PRIMARY AND SECONDARY OUTCOME MEASURES: The dose-response relationship between sleep duration and possible sarcopenia. RESULTS: During 4 years of follow-up, 964 (19.14%) participants developed possible sarcopenia. Compared with participants who slept 6-8 hours per night, those with shorter sleep duration (<6 hours per night) were independently associated with 22% (OR, 1.22; 95% CI, 1.04 to 1.44) increased risk of developing possible sarcopenia and 27% (OR, 1.27; 95% CI, 1.04 to 1.57) increased risk of developing low handgrip strength after controlling for potential confounders. Long sleep duration (>8 hours per night) was not significantly associated with incident possible sarcopenia. The plots of restricted cubic splines exhibited an atypical inverse J-shaped association between sleep duration and possible sarcopenia. Subgroup analysis showed a stronger association between sleep duration and possible sarcopenia in participants aged 45-59 years and composed of male populations. CONCLUSIONS: Short sleep duration was a potential risk factor for possible sarcopenia and low handgrip strength. The improvement of sleep duration should be considered a target in early preventive and administrative strategies against the development of handgrip strength decline and further reduced the occurrence of sarcopenia.