Low Grip Strength Research Articles

Low grip strength and gait speed as markers of dependence regarding basic activities of daily living: the FIBRA study.

Marincolo et al. showed that older adults without limitations in basic activities of daily living at baseline presented with an 11.7% concomitant presence of functional dependence, slow gait speed, and low muscle strength at follow-up. Slow gait speed remains a predictor of dependence in basic activities of daily living. To determine whether low muscle strength and low gait speed increase the risk of disability related to basic activities of daily living in community-dwelling older adults. A longitudinal study (9 years of follow-up) was conducted with 390 older adults who were independent in basic activities of daily living at baseline and answered the Katz Index at follow-up. Associations were determined using Pearson's χ2 test with a 5% significance level and logistic regression analysis. Increases in prevalence between baseline and follow-up were observed for low muscle strength (17.5%-38.2%), slow gait speed (26.0%-81.1%), and functional dependence (10.8%-26.6%). At follow-up, 11.7% of the participants had concomitant functional dependence, slow gait speed, and low muscle strength. Slow gait speed remained a predictor of dependence in basic activities of daily living (odds ratio=1.90; 95% confidence interval=1.06-3.41). Slow gait speed is a predictor of functional dependence, constituting an important variable for screening functional decline.

Associations and Mediating Pathways Between Childhood Adversity and Risk of Dementia: A Cohort Study in the UK Biobank.

While childhood adversity (CA) is known to be associated with multiple adverse outcomes, its link with dementia is an area with limited exploration and inconsistent agreement. The study aimed to examine the longitudinal associations of CA with incident all-cause dementia and to quantify the potential mediating pathways. Data from the UK Biobank. CA, encompassing neglect and abuse, was evaluated retrospectively by an online mental health questionnaire. Physical performance, psychological factors, lifestyles, and biological indicators assessed at baseline were considered potential mediators. Incident all-cause dementia was defined by International Classification of Diseases, Tenth Revision codes obtained through self-reported medical conditions, primary care, hospital admission, and death registrations. Cox proportional hazard models were applied to estimate the longitudinal associations. Mediation analyses were conducted on potential mediators to examine their contribution. This cohort study comprised 150152 nondemented individuals (mean [SD] age, 55.9 [7.7] years) at baseline (2006-2010). Compared to individuals who did not experience CA, those exposed to any CA exhibited a 30.0% higher risk of dementia (hazard ratio = 1.300, 95% confidence interval [CI]: 1.129-1.496). Each additional CA was associated with a 15.5% (95% CI: 8.8%-22.5%, pfor trend < .001) increased dementia risks. Depression, smoking, and low grip strength explained 8.7%, 2.4%, and 0.9% of the associations, respectively. Biomarkers involving inflammation, erythrocytes, liver, and kidney function mediated the associations by 0.6%-1.4%. The study revealed the detrimental effects of CA on dementia and identified some potential mediators, namely depression, smoking, low grip strength, and several targeted biomarkers. In addition to calling more attention to CA, the findings underscore the importance of interventions targeting modifiable mediators in preventing dementia.

Brain complexity in stroke recovery after bihemispheric transcranial direct current stimulation in mice.

Stroke is one of the leading causes of disability worldwide. There are many different rehabilitation approaches aimed at improving clinical outcomes for stroke survivors. One of the latest therapeutic techniques is the non-invasive brain stimulation. Among non-invasive brain stimulation, transcranial direct current stimulation has shown promising results in enhancing motor and cognitive recovery both in animal models of stroke and stroke survivors. In this framework, one of the most innovative methods is the bihemispheric transcranial direct current stimulation that simultaneously increases excitability in one hemisphere and decreases excitability in the contralateral one. As bihemispheric transcranial direct current stimulation can create a more balanced modulation of brain activity, this approach may be particularly useful in counteracting imbalanced brain activity, such as in stroke. Given these premises, the aim of the current study has been to explore the recovery after stroke in mice that underwent a bihemispheric transcranial direct current stimulation treatment, by recording their electric brain activity with local field potential and by measuring behavioural outcomes of Grip Strength test. An innovative parameter that explores the complexity of signals, namely the Entropy, recently adopted to describe brain activity in physiopathological states, was evaluated to analyse local field potential data. Results showed that stroke mice had higher values of Entropy compared to healthy mice, indicating an increase in brain complexity and signal disorder due to the stroke. Additionally, the bihemispheric transcranial direct current stimulation reduced Entropy in both healthy and stroke mice compared to sham stimulated mice, with a greater effect in stroke mice. Moreover, correlation analysis showed a negative correlation between Entropy and Grip Strength values, indicating that higher Entropy values resulted in lower Grip Strength engagement. Concluding, the current evidence suggests that the Entropy index of brain complexity characterizes stroke pathology and recovery. Together with this, bihemispheric transcranial direct current stimulation can modulate brain rhythms in animal models of stroke, providing potentially new avenues for rehabilitation in humans.

Cross-sectional associations between temporal patterns and composition of upright and stepping events with physical function in midlife: Insights from the 1970 British Cohort Study.

Age-related decline in physical functioning has significant implications for health in later life but declines begin earlier in midlife. Physical activity (PA) volume is associated with physical function, but the importance of the pattern in which PA is accumulated is unclear. This study investigates associations between patterns of PA accumulation, including the composition, variation, and temporal distribution of upright and stepping events, with physical function in midlife. Participants (n = 4378) from the 1970 British Cohort Study wore an activPAL3 accelerometer on the thigh for 7 consecutive days. Exposure measures included a suite of metrics describing the frequency, duration, and composition of upright events, as well as the duration and volume (total steps) of stepping events. In addition, patterns of accumulation of upright and sedentary events were examined including how fragmented/transient they were (upright-to-sedentary transition probability [USTP]) and their burstiness (the tendency for events to be clustered together followed by longer interevent times). Physical function outcomes included grip strength (GS), balance, and SF-36 physical functioning subscale (SF-36pf). Cross-sectional analyses included multivariable linear regression models to assess associations, adjusting for covariates including overall PA volume (mean daily step count). Higher upright event burstiness was associated with higher GS, and higher USTP was associated with lower GS. Duration and step volume of stepping events were positively associated with SF-36pf in females. Step-weighted cadence was positively associated with SF-36pf and balance. Contradictory findings were also present (e.g., more transient stepping events were associated with better GS) particularly for GS in males. Inconsistencies between sexes were observed across some associations. Our study reveals that diverse patterns of PA accumulation exhibit distinct associations with various measures of physical function in midlife, irrespective of the overall volume. Contradictory findings and inconsistency between sexes warrant further investigation. Patterns of PA accumulation, in addition to volume, should be considered in future PA research. Longitudinal studies are required to determine whether a given volume of activity accumulated in different patterns, impacts associations between PA and health outcomes.

A Study of Blood Pressure and Physical Fitness in People with Intellectual Disabilities in South Korea.

Individuals with intellectual disabilities have a shorter lifespan and significantly higher prevalence of conditions such as hypertension and cardiovascular diseases than healthy individuals. Thus, assessing the elements that contribute to their physical fitness is crucial. This cross-sectional study examined the relationship between the blood pressure and physical fitness of people with intellectual disabilities in South Korea, considering differences across sexes, age groups, physical attributes, and disability levels. It used data from 8502 individuals with intellectual disabilities aged 20-59 years who participated in a survey of a National Fitness Standard Center (NFSC) between 2018 and 2021. A series of t-tests, one-way analysis of variance, logistic regression, and the four-quartile method were used for data analyses. The results showed differences in physical fitness levels between men and women considering all aspects except for BMI (Body Mass Index), with men showing higher blood pressure levels. Lower grip strength, lower PEI (physical efficiency index) scores, and higher BMI were associated with increased blood pressure. Additionally, individuals with higher levels of disability tended to have lower levels of physical fitness, while higher physical fitness levels were associated with lower blood pressure. Therefore, low fitness levels and hypertension risk may be important health indicators for people with intellectual disabilities.

Decreased grip strength is associated with paraspinal muscular oxidative stress in female lumbar degenerative disease patients.

We aimed to investigate the relationship between superoxide dismutase 2-related oxidative stress in the paraspinal muscles and spinal alignment, clinical skeletal muscle parameters, and mitochondrial function. Multifidus muscle samples from patients who underwent posterior lumbar surgery were analyzed. Patients with diseases affecting oxidative stress and spinal alignment were excluded. The superoxide dismutase 2 redox index was defined as the ratio of reactive oxygen species (superoxide) to antioxidant enzymes (superoxide dismutase 2) and was used as an index of oxidative stress. Patients were divided into two groups based on the superoxide dismutase 2 redox index. Spinal alignment, clinical skeletal muscle parameters, and succinic dehydrogenase (SDH) mean grayscale value were compared between the groups, with analyzes for both sexes. Multiple regression analyzes were used to adjust for the confounding effect of age on variables showing a significant difference between the two groups. Thirty-five patients with lumbar degenerative diseases were included. No significant differences were observed between the two groups for any of the parameters in males; however, females with a higher superoxide dismutase 2 redox index had greater lumbar lordosis, lower grip strength, and higher SDH mean grayscale value than those with a lower index. Multiple regression analyzes revealed that the superoxide dismutase 2 redox index was an independent explanatory variable for lumbar lordosis, grip strength, and SDH mean grayscale value in female patients. In conclusion, superoxide dismutase 2-related oxidative stress in the paraspinal muscles was associated with mitochondrial dysfunction and decreased grip strength in female lumbar degenerative disease patients.

Association between sleep traits and sarcopenia-related traits: A two-sample bidirectional Mendelian randomization study.

Despite limited evidence regarding the impact of sleep quality on sarcopenia, it is widely recognized as being associated with various diseases. This study aimed to explore the causal relationship between sleep traits and sarcopenia-related traits. This study utilized a two-sample bidirectional Mendelian randomization analysis. Genetic genome-wide summary data of sleep quality indicators, including chronotype, morning wake-up time, sleep duration, daytime napping, insomnia and daytime dozing, were used. Data on sarcopenia-related traits, such as appendicular lean mass, grip strength of both hands, walking pace and waist circumference, were collected from a large cohort study. The primary method used was the inverse-variance weighted analysis. A causal association was found between chronotype and appendicular lean mass (odds ratio [OR] 1.019, 95% confidence interval [CI] 1.016-1.211, P = 0.021). Napping during the day was connected with walking pace (OR 0.879, 95% CI 0.834-0.928, P = 2.289 × 10-6) and waist circumference (OR 1.234, 95% CI 1.081-1.408, P = 0.002). Insomnia was related to lower grip strength of the right hand (OR 0.844, 95% CI 0.747-0.954, P = 0.007), left hand (OR 0.836, 95% CI 0.742-0.943, P = 0.003), as well as walking pace (OR 0.871, 95% CI 0.798-0.951, P = 0.002). Furthermore, the reverse Mendelian randomization analysis showed associations between certain sarcopenia-related traits and poor sleep quality. Some sleep traits were associated with the occurrence of sarcopenia. These findings emphasized the significance of prioritizing sleep quality as a preventive measure against sarcopenia. Geriatr Gerontol Int 2024; 24: 537-545.

Identifying characteristics and clinical conditions associated with hand grip strength in adults: the Project Baseline Health Study.

Low hand grip strength (HGS) is associated with several conditions, but its value outside of the older adult population is unclear. We sought to identify the most salient factors associated with HGS from an extensive list of candidate variables while stratifying by age and sex. We used data from the initial visit from the Project Baseline Health Study (N = 2502) which captured detailed demographic, occupational, social, lifestyle, and clinical data. We applied MI-LASSO using group methods to determine variables most associated with HGS out of 175 candidate variables. We performed analyses separately for sex and age (< 65 vs. ≥ 65years). Race was associated with HGS to varying degrees across groups. Osteoporosis and osteopenia were negatively associated with HGS in female study participants. Immune cell counts were negatively associated with HGS for male participants ≥ 65 (neutrophils) and female participants (≥ 65, monocytes; < 65, lymphocytes). Most findings were age and/or sex group-specific; few were common across all groups. Several of the variables associated with HGS in each group were novel, while others corroborate previous research. Our results support HGS as a useful indicator of a variety of clinical characteristics; however, its utility varies by age and sex.

Longitudinal association of grip strength with cardiovascular and all-cause mortality in older urban Lithuanian population.

Ageing populations experience greater risks associated with health and survival. It increases the relevance of identifying variables associated with mortality. Grip strength (GS) has been identified as an important biomarker for all cause and cardiovascular mortality, however, its prognostic value has not been studied in Lithuania. The aim of the present study is to evaluate the relationship of GS to vital status in a representative sample of the Lithuanian 45-72-year-old urban population during the period of 12 years of follow-up and to explore associations of GS with all-cause mortality and mortality from cardiovascular diseases (CVD). Within the framework of the international study Health, Alcohol and Psychosocial Factors in Eastern Europe (HAPIEE) 7,115 men and women 45-72 years of age were examined in the baseline survey (2006 to 2008). Data from the Official Lithuanian Mortality Register were used to evaluate CVD and all-cause mortality from follow-up till 2020. Cox proportional hazards regression was used, and four models for all-cause and CVD mortality were assessed. The mean GS was significantly higher among survivors' men and women as compared to individuals deceased from CVD and other causes of death. In survivor men and women groups, minimal values of GS in all terciles were higher as compared to all three deceased groups. In both men and women groups, the lowest GS (1st tercile) was associated with a significantly higher risk of all-cause and CVD mortality as compared to the highest levels of GS (3rd tercile) in three Cox regression models. In both men and women were found to have a 1.34- and 1.35-fold higher risk of all-cause mortality, respectively, at lower GS, but no significant difference in the risk of CVD mortality. When GS was treated in all models as decrement per 1kg and decrement per 1 SD, in both men and women, the risk of all-cause mortality significantly increased with decreasing of GS. The mean GS was significantly higher among survivors' men and women as compared to deceased from CVD and other causes of death. Risk of all-cause mortality significantly increased with decreasing of GS.

Sarcopenia as a Robust Predictor of Readmission within 6 Months among Individuals Experiencing Acute Stroke.

Sarcopenia negatively affects the short-term prognosis of hospitalized older adults. However, no evidence currently supports a direct relationship between sarcopenia and readmission among individuals who have experienced an acute stroke. Therefore, we investigated whether sarcopenia is associated with readmission after discharge. This retrospective cohort study included patients who had experienced acute stroke. Sarcopenia was defined as the coexistence of low skeletal muscle mass index (SMI) and grip strength. We applied the log-rank test and Cox proportional hazards regression analysis to analyze whether sarcopenia, low SMI, and low grip strength were associated with readmission within 6 months. Among 228 included patients (mean age, 72.8 years; 146 males), the prevalence of sarcopenia was 24.6% (n=56; male 17.8%; female 36.6%). Cox proportional hazards regression analysis using the propensity score as a covariate revealed that sarcopenia (hazard ratio [HR]=7.21; 95% confidence interval [CI] 1.45-35.8; p=0.016) and low skeletal muscle mass (HR=7.40; 95% CI 1.14-48.1; p=0.036), but not low grip strength (HR=1.42; 95% CI 0.281-7.21; p=0.670), were significantly associated with readmission for stroke within 6 months. Sarcopenia was negatively associated with readmission within 6 months of stroke onset in patients in Japan who had experienced an acute stroke. These findings suggest that the identification of sarcopenia may facilitate prognostic prediction from the acute stage and intervention(s) to prevent rehospitalization.

Mapping the causal associations of cytokines with sarcopenia and aging traits: Evidence from bidirectional Mendelian randomization.

Cytokines and growth factors may serve as a bridge in studying the causal relationships between inflammaging and sarcopenia due to their roles in inflammaging. In this study, we aim to explore the causal association of cytokines with sarcopenia and aging traits and further identify the significant inflammation factors. Bidirectional Mendelian randomization (MR) analysis was used to identify the causality. Forty-one kinds of circulation cytokines and growth factors were set as exposures, and the data were from a summary genome-wide association study (GWAS) containing three cohorts with 8293 healthy participants of European ancestry from 1983 to 2011. Hand grip strength, adjusted appendicular lean mass (AALM), usual walking pace, moderate-to-vigorous physical activity (MVPA) levels, able to walk or cycle unaided for 10min (AWCU10) and telomere length were selected as outcomes. Data for outcomes were obtained from meta-GWAS and the UK Biobank, and sample sizes ranged from 69537 to 472174. Low hand grip strength was defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and Foundation for the National Institutes of Health (FNIH) cut-off points, respectively. Other outcome traits were defined and measured according to the UK Biobank and raw cohorts' criteria. We set two significance thresholds for single nucleotide polymorphisms (SNPs) associated with exposures to obtain adequate SNPs (5×10-6 and 5×10-8). Inverse-variance weighted, MR-Egger and weighted median were employed to estimate the causality. Twenty-seven factors were identified to relate to sarcopenia and aging traits causally, and most were associated with only one outcome trait. IL16 (interleukin-16), CTACK (cutaneous T-cell attracting chemokine), MIP1b (macrophage inflammatory protein 1b) and PDGFbb (platelet-derived growth factor BB) were proven to relate causally to at least one sarcopenia and aging trait in both analyses with two significance thresholds. IL16 was causally associated with hand grip strength (0.977 [0.956-0.998] for EWGSOP and 0.933 [0.874-0.996] for FNIH), AALM (0.991 [0.984, 0.998]), MVPA (0.997 [0.995-1.000]) and AWCU10 (1.008 [1.003-1.013]). CTACK was proven to relate causally to hand grip strength (1.013 [1.007-1.019] for EWGSOP and 1.090 [1.041-1.142] for FNIH), AWCU10 (0.990 [0.986-0.994]) and telomere length (0.998 [0.983-0.994]). The results indicated that MIP1b has a causal effect on hand grip strength (1.032 [1.001-1.063] for EWGSOP), AWCU10 (0.994 [0.988-1.000] and 0.993 [0.988-0.998]) and telomere length (1.006 [1.000-1.012]). PDGFbb may causally relate to AALM (1.016 [1.001-1.030]) and telomere length (1.011 [1.007-1.015]). Reserve MR analyses also proved their unidirectional causal effects. Twenty-seven factors were causally related to sarcopenia and aging traits, and the causal effects of IL16, CTACK, MIP1b and PDGFbb were proven in both analyses with two significance thresholds.

Handgrip Strength Predicts Survival in Patients With Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a common cancer with a poor prognosis and is associated with a high prevalence of cachexia, a metabolic syndrome of muscle wasting due to complex mechanisms. In addition to loss of muscle mass, cancer patients also experience functional deterioration. The aim of this study is to determine whether there is an association between muscle mass and function and clinical outcomes, particularly survival. We performed a prospective cohort study including all patients with PDAC at Monash Health from March 2016 to December 2017. We conducted body composition analysis for myopenia and handgrip strength testing. We constructed Kaplan-Meier curves to estimate whether myopenia and low hand grip strength were associated with poorer survival. Myopenia was not associated with a significant difference in PDAC-specific survival (log-rank P = 0.60). However, low handgrip strength was associated with significantly worse PDAC-specific survival compared with other patients (log-rank hazard ratio, 1.88; 95% confidence interval, 1.15-3.09; P = 0.004). The relationship between survival in PDAC and handgrip strength, but not anatomical muscle mass, suggests that functional testing of strength may be important in prognostication of patients with PDAC, alongside existing tools such as the Eastern Cooperative Oncology Group performance status.

Characteristics Associated With Elevated Time Below Range in Elderly Patients With Type 1 Diabetes Using an Automated Insulin Delivery System.

This study investigated the characteristics associated with an increased risk of hypoglycemia, in elderly patients with type 1 diabetes mellitus (T1D) using automated insulin delivery (AID) systems. Cross-sectional observational study including patients >60 years, using sensor-augmented insulin pump therapy with predictive low-glucose management (SAPT-PLGM), hybrid closed-loop (HCL), and advanced hybrid closed-loop (AHCL), for more than three months. A geriatric assessment was performed, and body composition was determined to investigate its association with achieving time below range (TBR) <70 mg/dL goals. The study included 59 patients (47.5% of men, mean age of 67.6 years, glycated hemoglobin [HbA1c] of 7.5 ± 0.6%, time in range (TIR) 77.8 ± 9.9%). Time below range <70 and <54 mg/dL were 2.2 ± 2.3% and 0.4 ± 0.81%, respectively. Patients with elevated TBR <70 mg/dL (>1%) had higher HbA1c levels, lower TIR, elevated time above range (TAR), and high glycemic variability. Regarding body composition, greater muscle mass, grip strength, and visceral fat were associated with a lower TBR <70 mg/dL. These factors were independent of the type of technology used, but TIR was higher when using AHCL systems compared with SAPT-PLGM and HCL systems. In elderly patients treated with AID systems with good functional status, lower lean mass, lower grip strength, and lower visceral fat percentage were associated with TBR greater than 1%, regardless of the device used. A similar finding along was found with CGM indicators such as higher HbA1c levels, lower TIR, higher TAR, and higher CV. Geriatric assessment is crucial for personalizing patient management.

Mortality, bone density and grip strength: lessons from the past and hope for the future?

Therapeutic advances in the management of osteoporosis and sarcopenia have occurred at different rates over the last 2 decades. Here we examine associations between grip strength and BMD with subsequent all-cause and cause-specific mortality in a UK community-dwelling cohort. Data from 495 men and 414 women from the Hertfordshire Cohort Study were analysed. Grip strength was assessed by grip dynamometry, femoral neck BMD was ascertained using DXA and deaths were recorded from baseline (1998-2004) until 31 December 2018. Grip strength and BMD in relation to mortality outcomes (all-cause, cardiovascular-related, cancer-related and mortality due to other causes) were examined using Cox regression with adjustment for age and sex. The mean baseline age of participants was 64.3 years (s.d. 2.5) and 65.9 years (s.d. 2.6) in men and women, respectively. Lower grip strength was associated with increased risk of all-cause mortality [hazard ratio (HR) 1.30 (95% CI 1.06, 1.58), P = 0.010] and cardiovascular-related mortality [HR 1.75 (95% CI 1.20, 2.55), P = 0.004]. In contrast, BMD was not associated with any of the mortality outcomes (P > 0.1 for all associations). We report strong relationships between grip strength and mortality compared with BMD. We hypothesize that this may reflect better recognition and treatment of low BMD in this cohort.

Mortality and disability risk among older adults unable to complete grip strength and physical performance tests: a population-based cohort study from China

BackgroundThe link between low grip strength, diminished physical performance, and adverse health outcomes in older adults has been well-established. However, the impact of older adults who cannot complete these tests on disability and mortality rates remains unexplored without longitudinal study.MethodsWe collected data from the China Health and Retirement Longitudinal Study (CHARLS). Participants aged 60–101 were enrolled at baseline. We analyzed the prevalence of populations unable to complete handgrip strength (HGS), gait speed (GS), and five times chair stand test (FTCST). Completing risk models were used to estimate the risk of mortality and disability over seven years.ResultsA total of 3,768 participants were included in the analysis. The percentage of older adults unable to complete the GS and FTCST tests increased notably with age, from 2.68 to 8.90% and 2.60–20.42%, respectively. The proportion of older people unable to perform the HGS was relatively stable, ranging from 1.40 to 3.66%. Compared to older adults who can complete these tests, those who cannot perform FTCST face a significantly higher risk of mortality, with 49.1% higher risk [hazard ratio (HR) = 1.491, 95% CI = 1.156, 1.922; subdistribution hazard ratio (SHR) = 1.491, 95%CI = 1.135,1.958)]. Participants who were unable to complete the GS test had a higher risk of developing ADL disability, regardless of whether they were compared to the lowest-performing group (HR = 1.411, 95%CI = 1.037,1.920; SHR = 1.356, 95%CI = 1.030,1.785) or those who can complete the GS (HR = 1.727, 95%CI = 1.302,2.292; SHR = 1.541, 95%CI = 1.196,1.986). No statistically significant difference in the risk of developing ADL disability among older adults who were unable to complete the HGS test compared with either the poorest performing group (HR = 0.982, 95% CI = 0.578, 1.666; SHR = 1.025, 95% CI = 0.639, 1.642) or those who were able to complete the HGS test (HR = 1.008, 95% CI = 0.601, 1.688; SHR = 0.981, 95% CI = 0.619, 1.553). The risk of all-cause mortality was not significantly different for older adults who were unable to complete the HGS test compared to those with the worst performance (HR = 1.196, 95%CI = 0.709–2.020; SHR = 1.196, 95%CI = 0.674, 2.124) or those who were able to complete the test (HR = 1.462, 95%CI = 0.872–2.450; SHR = 1.462, 95%CI = 0.821,2.605).ConclusionThe risks of adverse events faced by older adults unable to complete the tests vary, indicating the necessity for future research to conduct separate analyses on this high-risk population.

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

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. We included 5568 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. 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. 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.

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.

The causal association between circulating cytokines with the risk of frailty and sarcopenia under the perspective of geroscience.

Circulating cytokines were considered to play a critical role in the initiation and propagation of sarcopenia and frailty from observational studies. This study aimed to find the casual association between circulating cytokines and sarcopenia and frailty from a genetic perspective by two-sample Mendelian randomization (MR) analysis. Data for 41 circulating cytokines were extracted from the genome-wide association study dataset of 8,293 European participants. Inverse-variance weighted (IVW) method, MR-Egger, and weighted median method were applied to assess the relationship of circulating cytokines with the risk of aging-related syndromes and frailty. Furthermore, MR-Egger regression was used to indicate the directional pleiotropy, and Cochran's Q test was used to verify the potential heterogeneity. The "leave-one-out" method was applied to visualize whether there was a causal relationship affected by only one anomalous single-nucleotide polymorphisms. Genetic predisposition to increasing levels of interleukin-10 (IL-10), IL-12, and vascular endothelial growth factor (VEGF) was associated with the higher risk of low hand grip strength according to the IVW method [R = 1.05, 95% CI = 1.01-1.10, P = 0.028, false discovery rate (FDR)-adjusted P = 1.000; OR = 1.03, 95% CI = 1.00-1.07, P = 0.042, FDR-adjusted P = 0.784; OR = 1.02, 95% CI = 1.00-1.05, P = 0.038, FDR-adjusted P = 0.567]. Furthermore, genetically determined higher macrophage colony-stimulating factors (M-CSFs) were associated with a lower presence of appendicular lean mass (OR = 1.01, 95% CI = 1.00-1.02, P = 0.003, FDR-adjusted P = 0.103). Monokine induced by interferon-γ (MIG) and tumor necrosis factor-beta (TNF-β) were associated with a higher risk of frailty (OR = 1.03, 95% CI = 1.01-1.05, P < 0.0001, FDR-adjusted P= 0.012; OR = 1.01, 95% CI = 1.00-1.03, P = 0.013, FDR-adjusted P = 0.259). In this study, we did not find heterogeneity and horizontal pleiotropy between the circulating cytokines and the risk of frailty and sarcopenia. Genetic predisposition to assess IL-10, IL-12, and VEGF levels was associated with a higher risk of low hand grip strength and M-CSF with the presence of appendicular lean mass. The high levels of TNF-β and MIG were associated with a higher risk of frailty. More studies will be required to explore the molecular biological mechanisms underlying the action of inflammatory factors.

A Mendelian randomization analysis identifies causal association between sarcopenia and gastroesophageal reflux disease.

The incidence of gastroesophageal reflux disease (GERD) is increasing with the advancement of world population aging, affecting the population health worldwide. Recently, there were several researches to suggest the association between GERD and sarcopenia, but evidence supporting the causal effect was absent. The purpose of this study is to determine the causal relationship between GERD and sarcopenia through a Mendelian randomization (MR) study. We conducted an MR analysis by using summary-level data of genome-wide association studies (GWASs) in the European population. The inverse variance weighted (IVW) method was used as the primary analytical method for evaluating causality. In addition, four other MR methods were performed to supplement the IVW results. We also used the Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) and the multivariable Mendelian randomization (MVMR) to validate the robustness of our results. IVW analysis revealed a causally positive correlation between low hand grip strength (OR = 1.2358, 95% C.I.: 1.0521-1.4514, P = 0.0099), decreased walking pace (OR = 0.1181, 95% C.I.: 0.0838-0.1666, P = 4×10-34), and decreased appendicular lean mass (ALM) (OR = 0.8612, 95% C.I.: 0.8263-0.8975, P = 1×10-12) and GERD. MR-PRESSO and MVMR analysis confirmed the association evidence. In conclusion, this MR analysis supported the causal association between sarcopenia-related traits and GERD.

Higher-level competence: Results from the Integrated Longitudinal Studies on Aging in Japan (ILSA-J) on the shape of associations with impaired physical and cognitive functions.

This study aimed to examine the relationships between levels of competence and impaired physical and cognitive functions in older adults. We used a data set of the Integrated Longitudinal Studies on Aging in Japan for 2017 including 5475 community-dwelling older adults. Levels of competence were assessed using the Japan Science and Technology Agency Index of Competence (JST-IC). Grip strength (low grip strength: <28 kg for men and <18 kg for women) and gait speed (slow gait speed: <1.0 m/s for both sexes) were evaluated as physical function measurements, and the Mini-Mental State Examination (cognitive decline: <24 on the Mini-Mental State Examination) was used to assess cognitive function. The JST-IC had areas under the curve estimated from receiver operating characteristic analysis ranging from 0.65 to 0.73 for detecting low function as assessed by these tests. Restricted cubic spline curves showed that the shape of the association between the JST-IC and impaired function depended on sex and the test used. The comparison between perfect and imperfect JST-IC scores showed significant differences in the prevalence of low grip strength in both sexes, slow gait speed in women, and cognitive decline in men. It may be insufficient to identify those with impaired physical or cognitive function using the JST-IC. The shape of the association with the JST-IC varies across their measurements. Our findings can help interpret JST-IC scores in the context of low physical and cognitive functions. Geriatr Gerontol Int 2024; 24: 352-358.