Association between oxidative balance score and skeletal muscle mass and strength: NHANES from 2011 to 2018.

Objective: Oxidative stress is a risk factor for sarcopenia. The Oxidative Balance Score (OBS) is a widely employed tool for evaluating the oxidative stress-related exposures from dietary and lifestyle factors. In this study, we aimed to conducted to explore the relationship between OBS and skeletal muscle mass and strength. Methods: 6,438 subjects from 2011 to 2018 and 5,414 from 2011 to 2014 from the National Health and Nutrition Examination Survey (NHANES) were selected for analysis. The correlations between OBS and skeletal muscle mass and handgrip strength were investigated using multivariate logistic regression and linear regression analysis. Results: Compared with lowest OBS, participants with OBS in the highest quartile had lower risk of low skeletal muscle mass (OR = 0.173 (0.120 ~ 0.248), p < 0.0001) and low handgrip strength (ß = 0.173 (0.120 ~ 0.248), p = 0.011). The negative association also were found between dietary/lifestyle OBS and skeletal muscle mass (OR = 0.268 (0.178 ~ 0.404), p < 0.0001; OR = 0.231 (0.130 ~ 0.410), p < 0.0001) and handgrip strength (ß = 1.812 (0.555 ~ 3.071), p = 0.008; ß = -2.255 (-3.430 ~ -1.079), p < 0.001) independently. The positive association remains significant, especially among men and those with higher education levels by subgroup analysis. Conclusion: All of these results indicated a negative association between OBS and low skeletal muscle mass and handgrip strength. An antioxidant-rich diet and healthy lifestyle are crucial for enhancing skeletal muscle mass and strength.

Monitoring handgrip strength to motivate lifestyle choices for patients with diabetes type 2 - a pragmatic randomised controlled trial.

METHODS: Measurement of HGS with Jamar dynamometers was added to annual check-ups for patients with T2DM by diabetes nurses in primary care with feedback about normal values for age and sex in the intervention group. The control group had standard check-ups. Change in self-reported PA level was measured with questionnaires. RESULTS: Seven clinics and 334 patients participated. The intervention led to similar effects on PA in both groups. Patients with T2DM had comparable HGS to the general public. Regression analyses showed statistically significantly higher HGS in the intervention group than in the control group at follow-up and no improvement in PA, HbA1c, or waist circumference. Increased HGS was found for older people, men, and people with normal-to-high inclusion HGS, while patients with low inclusion HGS reduced their strength levels. CONCLUSIONS: Measuring HGS and giving feedback to patients with T2DM can lead to increased HGS but does not seem to affect general PA level, HbA1c, or waist circumference. People over 65 years, men, and people with normal-to-high HGS were influenced positively by the intervention. Patients with low HGS may need personalised support to increase physical activity and improve function.ClinicalTrials registration: NCT03693521.

Enhancing predictive validity of motoric cognitive risk syndrome for incident dementia and all-cause mortality with handgrip strength: insights from a prospective cohort study.

Background: This study aimed to assess whether integrating handgrip strength (HGS) into the concept of motoric cognitive risk (MCR) would enhance its predictive validity for incident dementia and all-cause mortality. Methods: A cohort of 5, 899 adults from the Health and Retirement Study underwent assessments of gait speed, subjective cognitive complaints, and HGS were involved. Over a 10-year follow-up, biennial cognitive tests and mortality data were collected. Cox proportional hazard analyses assessed the predictive power of MCR alone and MCR plus HGS for incident dementia and all-cause mortality. Results: Patients with MCR and impaired HGS (MCR-HGS) showed the highest adjusted hazard ratios (AHR) for dementia (2.33; 95% CI, 1.49-3.65) and mortality (1.52; 95% CI, 1.07-2.17). Even patients with MCR and normal HGS (MCR-non-HGS) experienced a 1.77-fold increased risk of incident dementia; however, this association was not significant when adjusted for socioeconomic status, lifestyle factors, and medical conditions. Nevertheless, all MCR groups demonstrated increased risks of all-cause mortality. The inclusion of HGS in the MCR models significantly improved predictive discrimination for both incident dementia and all-cause mortality, as indicated by improvements in the C-statistic, integrated discrimination improvement (IDI) and net reclassification indices (NRI). Conclusion: Our study underscores the incremental predictive value of adding HGS to the MCR concept for estimating risks of adverse health outcomes among older adults. A modified MCR, incorporating HGS, could serve as an effective screening tool during national health examinations for identifying individuals at risk of dementia and mortality.

Association between low handgrip strength and incontinence among Chinese middle-aged and older people: A cross-sectional study.

Objective: Incontinence seriously affects the lives of middle-aged and older people. Pelvic floor muscle assessment is very important for incontinence, and handgrip strength can be used as an auxiliary diagnostic tool. Our study aims to find new cutoff points of handgrip strength as early indicators of incontinence and analyze the association between low handgrip strength and incontinence among Chinese middle-aged and older people. Methods: Participants were recruited from the 2015 China Health and Retirement Longevity Study. Receiver operating characteristic (ROC) curves were used to find the handgrip strength cutoff point. Logistic regression analysis was performed to explore other incontinence-related risk factors. Results: The study included 10,229 middle-aged and older people. Compared with normal handgrip strength participants, medium strength participants had 1.510 [men, 95% confidence interval (CI) = 1.017-2.243] and 1.792 (women, 95% CI = 1.294-2.480) times greater risk of incontinence, and low strength participants had 2.420 (men, 95% CI = 1.787-3.277) and 1.516 (women, 95% CI = 1.130-2.032) times greater risk of incontinence. Trend test results showed that the risk of incontinence increased with decreasing handgrip strength in middle-aged and older people. Conclusions: Our study suggests that handgrip strength < 31 kg in men and < 20.5 kg in women is significantly associated with higher risk of incontinence in Chinese middle-aged and older people. The risk of incontinence increases with decreasing handgrip strength. Handgrip strength should be measured in routine physical examinations in middle-aged and older people for timely assessment and intervention in incontinence.

A neural signature for brain compensation in stroke with EEG and TMS: Insights from the DEFINE cohort study.

OBJECTIVE: This study aimed to explore the relationships between potential neurophysiological biomarkers and upper limb motor function recovery in stroke patients, specifically focusing on combining two neurophysiological markers: electroencephalography (EEG) and transcranial magnetic stimulation (TMS). METHODS: This cross-sectional study analyzed neurophysiological, clinical, and demographical data from 102 stroke patients from the DEFINE cohort. We searched for correlations of EEG and TMS measurements combined to build a prediction model for upper limb motor functionality, assessed by five outcomes, across five assessments: Fugl-Meyer Assessment (FMA), Handgrip Strength Test (HST), Finger Tapping Test (FTT), Nine-Hole Peg Test (9HPT), and Pinch Strength Test (PST). RESULTS: Our multivariate models agreed on a specific neural signature: higher EEG Theta/Alpha ratio in the frontal region of the lesioned hemisphere is associated with poorer motor outcomes, while increased MEP amplitude in the non-lesioned hemisphere correlates with improved motor function. These relationships are held across all five motor assessments, suggesting the potential of these neurophysiological measures as recovery biomarkers. CONCLUSION: Our findings indicate a potential neural signature of brain compensation in which lower frequencies of EEG power are increased in the lesioned hemisphere, and lower corticospinal excitability is also increased in the non-lesioned hemisphere. We discuss the meaning of these findings in the context of motor recovery in stroke.

Efficacy of Pea Protein Supplementation in Combination with a Resistance Training Program on Muscle Performance in a Sedentary Adult Population: A Randomized, Comparator-Controlled, Parallel Clinical Trial.

Animal-sourced whey protein (WPr) is the most popular protein supplement among consumers and has been shown to improve muscle mass and strength. However, due to allergies, dietary restrictions/personal choices, and growing demand, alternative protein sources are warranted. Sedentary adults were randomized to pea protein (PPr) or WPr in combination with a weekly resistance training program for 84 days. Changes in whole-body muscle strength (WBMS) including handgrip, lower body, and upper body strength, body composition, and product perception were assessed. The safety outcomes included adverse events, vital signs, clinical chemistry, and hematology. There were no significant differences in the change in WBMS, muscle mass, or product perception and likability scores between the PPr and WPr groups. The participants supplemented with PPr had a 16.1% improvement in WBMS following 84 days of supplementation (p = 0.01), while those taking WPr had an improvement of 11.1% (p = 0.06). Both study products were safe and well-tolerated in the enrolled population. Eighty-four days of PPr supplementation resulted in improvements in strength and muscle mass comparable to WPr when combined with a resistance training program in a population of healthy sedentary adults. PPr may be considered as a viable alternative to animal-sourced WPr without sacrificing muscular gains and product enjoyment.

Association between grip strength and walking pace with incidence of degenerative cervical myelopathy: a UK biobank observational study.

PURPOSE: This study investigates the association between handgrip strength, walking pace, and the incidence of degenerative cervical myelopathy (DCM) using the UK Biobank dataset. METHODS: We analyzed data from 364,716 UK Biobank participants without prior neurological conditions. Handgrip strength was measured with a dynamometer, and walking pace was self-reported. Cox proportional hazards models assessed hazard ratios (HRs) and 95% confidence intervals (CIs) for DCM development. RESULTS: The cohort, with an average age of 56.2 years (SD, 8.1) and 47.4% male, was followed for a median of 12.6 years. During this period, 3,993 participants (1.1%) developed DCM. A significant inverse correlation was found between handgrip strength and DCM incidence (P for trend < 0.001), with decreasing HRs for DCM across quartiles of increasing grip strength: HRs were 0.70 (95% CI: 0.64-0.76), 0.62 (95% CI: 0.57-0.68), and 0.59 (95% CI: 0.54-0.66) for the second, third, and fourth quartiles, respectively. Participants with average or brisk walking paces had a lower DCM risk (HR, 0.55; 95% CI: 0.50-0.61 and HR, 0.48; 95% CI: 0.43-0.54) compared to slow walkers. The greatest risk reduction was in those with both higher handgrip strength and faster pace (HR, 0.39; 95% CI: 0.34-0.44). CONCLUSIONS: Handgrip strength and walking pace are inversely associated with DCM incidence, suggesting their potential as cost-effective screening tools for identifying individuals at risk for DCM.

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.

Combination of handgrip strength and high-sensitivity modified Glasgow prognostic score predicts survival outcomes in patients with colon cancer.

Objective: Handgrip strength (HGS) and the high-sensitivity modified Glasgow prognostic score (HS-mGPS) are associated with the survival of patients with cancer. However, no studies have investigated the combined effect of HGS and HS-mGPS on the overall survival (OS) of patients with colon cancer. Methods: Prospective follow-up data of colon cancer patients undergoing radical resection from April, 2016 to September, 2019 were retrospectively collected. We combined the HGS and HS-mGPS to create a new composite index, HGS-HS-mGPS. The hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox regression models to assess the association between variables and OS. Risk factors on OS rates were investigated by Cox analyses and the nomogram was constructed using significant predictors and HGS-HS-mGPS. The predictive performance of the nomogram was evaluated by receiver operating characteristic curve and calibration curve. Results: This study included a total of 811 patients, of which 446 (55.0%) were male. The HGS optimal cut-off values of male and female patients were 28.8 and 19.72 kg, respectively. Multivariate analysis revealed that low HGS and high HS-mGPS were independent risk factors of colon cancer after adjusting confounders (adjusted HR = 3.20; 95% CI: 2.27-4.50; p < 0.001 and adjusted HR = 1.55; 95% CI: 1.12-2.14; p = 0.008 respectively). Patients with low HGS and high HS-mGPS had a 10.76-fold higher mortality risk than those with neither (adjusted HR = 10.76; 95% CI: 5.38-21.54; p < 0.001). A nomogram predicting 1-, 3-, and 5 year OS was constructed based on three clinicopathologic prognostic factors. Importantly, incorporating HGS-HS-mGPS into the nomogram model meaningfully improved the predictive performance. The decision curve analyses demonstrated the application value of the HGS-HS-mGPS nomogram for predicting OS of patients with colon cancer. Conclusion: HGS-HS-mGPS is associated with the survival of patients with colon cancer. These findings indicate the usefulness of HGS and HS-mGPS measurements in clinical practice for improving patient assessment, cancer prognosis, and precise intervention.

A Cross-Sectional Validation Study of Camry EH101 versus JAMAR Plus Handheld Dynamometers in Colorectal Cancer Patients and Their Correlations with Bioelectrical Impedance and Nutritional Status.

BACKGROUND: Reduced muscle strength (dynapenia) and mass (atrophy) are prognostic factors in oncology. Measuring maximal handgrip strength with dynamometers is feasible but limited by the cost of the reference device (JAMAR). METHODS: A cross-sectional study was conducted on colorectal cancer outpatients treated with chemotherapy or under active surveillance in our center from September 2022 to July 2023. Accuracy, reliability, and concordance were compared for two handheld dynamometers: the JAMAR Plus (the gold-standard device) and the Camry EH101 (a low-cost index device). A simultaneous nutritional diagnosis with GLIM criteria and bioelectrical impedance analysis (BIA) was carried out. RESULTS: A total of 134 participants were included. The median of maximal strength for the JAMAR Plus had a non-significant difference of 1.4 kg from the Camry EH101. The accuracy and reliability of the devices were high. Bland-Altman analysis showed a 0.8 kg bias and -4.1 to 5.6 kg limits of agreement (LoA); a 0.1 kg bias and -5.3 to 5.4 kg LoA in men; a 1.5 kg bias and -2.2 to 5.3 kg LoA in women. In total, 29.85% of the participants were malnourished. Prevalence of dynapenia increased from 3.67% with the JAMAR Plus to 5.14% with the Camry EH101. Both devices had a moderate and significant correlation with BIA-estimated muscle mass. CONCLUSIONS: The Camry EH101 was a cost-effective alternative to JAMAR Plus in our sample.

L-Citrulline Supplementation Improves Arterial Blood Flow and Muscle Oxygenation during Handgrip Exercise in Hypertensive Postmenopausal Women.

Endothelial dysfunction decreases exercise limb blood flow (BF) and muscle oxygenation. Acute L-Citrulline supplementation (CIT) improves muscle tissue oxygen saturation index (TSI) and deoxygenated hemoglobin (HHb) during exercise. Although CIT improves endothelial function (flow-mediated dilation [FMD]) in hypertensive women, the impact of CIT on exercise BF and muscle oxygenation (TSI) and extraction (HHb) are unknown. We examined the effects of CIT (10 g/day) and a placebo for 4 weeks on blood pressure (BP), arterial vasodilation (FMD, BF, and vascular conductance [VC]), and forearm muscle oxygenation (TSI and HHb) at rest and during exercise in 22 hypertensive postmenopausal women. Compared to the placebo, CIT significantly (p < 0.05) increased FMD (Δ-0.7 ± 0.6% vs. Δ1.6 ± 0.7%) and reduced aortic systolic BP (Δ3 ± 5 vs. Δ-4 ± 6 mmHg) at rest and improved exercise BF (Δ17 ± 12 vs. Δ48 ± 16 mL/min), VC (Δ-21 ± 9 vs. Δ41 ± 14 mL/mmHg/min), TSI (Δ-0.84 ± 0.58% vs. Δ1.61 ± 0.46%), and HHb (Δ1.03 ± 0.69 vs. Δ-2.76 ± 0.77 µM). Exercise BF and VC were positively correlated with improved FMD and TSI during exercise (all p < 0.05). CIT improved exercise artery vasodilation and muscle oxygenation via increased endothelial function in hypertensive postmenopausal women.

Concurrent validity and test-retest reliability of Squegg™ - smart dynamometer and handgrip trainer in healthy individuals.

Introduction: Handgrip strength is crucial for overall health and is often evaluated using hand dynamometers. Two hand dynamometers were used in the study: the Jamar® Hydraulic Hand Dynamometer and Squegg™ Smart Dynamometer and Handgrip Trainer, which is a relatively new, Bluetooth-enabled device to measure handgrip strength. The purpose of the study was to compare Jamar and Squegg to determine concurrent validity and, separately, test-retest reliability of Squegg. Methods: The cross-sectional study measured bimanual handgrip strength using the Jamar and Squegg in two sessions, following standard protocols. Participants were 18+ years old, with no hand disease or dysfunction. Spearman's rank correlations were used to evaluate concurrent validity between Jamar and Squegg. Test-retest reliability was evaluated with intraclass correlation coefficient (ICC) estimates and 95% confidence intervals calculated using a mean-rating (k = 2) absolute agreement, 2-way mixed effects model. Results: Data from 594 participants were used to evaluate concurrent validity. Moderately strong correlations between Jamar and Squegg values for the right hand (RH) (ρ = 0.670; p = .001) and Jamar and Squegg values for the left hand (LH) (ρ = 0.730; p = .001) were found, indicating 'good' concurrent validity. Test-retest reliability for Squegg ranged from good to excellent (RH, ICC = 0.911, 95% CI (0.895, 0.924), p = .001; LH, ICC = 0.928, 95% CI (0.915, 0.939), p = .001). Discussion: The Squegg demonstrated good concurrent validity with Jamar and good-to-excellent test-retest reliability. It can be recommended as an alternative to the Jamar as a handgrip strength measurement tool. Squegg, which uses Bluetooth technology, is a reliable and cost-effective option for consistent handgrip strength testing.

Force and Neuromuscular Responses During a Handgrip Hold to Failure Anchored to a Moderate Perceptual Intensity in Males.

OBJECTIVES: The current study investigated performance fatigability (PF) and time course of changes in force, electromyographic amplitude (EMG AMP) and frequency (EMG MPF), and neuromuscular efficiency (NME) during a sustained, isometric, handgrip hold to failure (HTF) using the rating of perceived exertion (RPE)-Clamp Model. METHODS: Twelve males performed a handgrip HTF anchored to RPE=5. The time to task failure (Tlim), force (N), EMG AMP and MPF, and NME (normalized force/ normalized EMG AMP) were recorded. Analyses included a paired samples t-test for PF at an alpha of p<0.05, 1-way repeated measures ANOVA across time and post-hoc t-tests (p<0.0025) for force, EMG AMP and MPF, and NME responses. RESULTS: The PF (pre- to post- maximal force % decline) was 38.2±11.5%. There were decreases in responses, relative to 0% Tlim, from 40% to 100% Tlim (force), at 30%, 60%, and 100% Tlim (EMG AMP), from 10% to 100% Tlim(EMP MPF), and from 50% to 65%, and 80% to 100% Tlim (NME) (p<0.0025). CONCLUSIONS: The RPE-Clamp Model in this study demonstrated that pacing strategies may be influenced by the integration of anticipatory, feedforward, and feedback mechanisms, and provided insights into the relationship between neuromuscular and perceptual responses, and actual force generating capacity.

Gut microbiota associations with chronic kidney disease: insights into nutritional and inflammatory parameters.

Introduction: The gut barrier, comprising gut microbiota, plays a pivotal role in chronic kidney disease (CKD) progression and nutritional status. This study aimed to explore gut barrier alterations in hemodialyzed (HD) patients, non-HD (NHD) CKD patients, and healthy volunteers. Methods: Our cross-sectional study enrolled 22 HD patients, 11 NHD patients, and 11 healthy volunteers. We evaluated fecal microbiota composition (assessed via bacterial 16S rRNA gene sequencing), fecal IgA levels, surrogate markers of gut permeability, serum cytokines, appetite mediators, nutritional status, physical activity, and quality of life. Results: HD patients exhibited significant alterations in fecal microbiota composition compared to healthy volunteers, with observed shifts in taxa known to be associated with dietary patterns or producing metabolites acting on human host. In comparison to healthy volunteers, individuals with HD patients exhibited elevated levels of inflammatory markers (CRP, IL-6 and TNF-α), glucagon-like peptide-2, and potential anorexigenic markers (including leptin and peptide YY). NHD patients had increased levels of CRP and peptide YY. Overall fecal microbiota composition was associated with height, soft lean mass, resting energy expenditure, handgrip strength, bone mineral content and plasma albumin and TNF-α. Discussion: Compared to healthy volunteers, HD patients have an altered fecal microbiota composition, a higher systemic inflammation, and a modification in plasma levels of appetite mediators. While some differences align with previous findings, heterogeneity exists likely due to various factors including lifestyle and comorbidities. Despite limitations such as sample size, our study underscores the multifaceted interplay between gut microbiota, physiological markers, and kidney function, warranting further investigation in larger cohorts.

Present but Ignored: Physical Condition and Health-Related Quality of Life in College-Aged Females with Generalized Joint Hypermobility.

BACKGROUND: Generalized joint hypermobility (GJH) is prevalent among young adults, necessitating effective monitoring of musculoskeletal health, particularly among college-aged females. This study aimed to identify physical fitness and health-related quality of life (HR-QoL) characteristics associated with GJH. METHODS: A total of 67 participants were assessed: 26 with GJH (mean age 20.06, SD 1.2 years), and 41 without (mean age 20.15, SD 2.2 years). Assessments included hypermobility, anthropometric data, foot posture, balance, flexibility, strength, and HR-QoL. We used the Mann-Whitney test for two independent samples, categorical variables were analyzed with Cramer's V test. The results indicated that participants with GJH exhibited inferior balance and back muscle static strength endurance but greater flexibility compared to those without GJH. Significant differences were observed in foot posture. However, handgrip strength, explosive strength, and abdominal muscle static strength endurance did not differ significantly between groups. No significant differences were observed in HR-QoL components between the two groups. In conclusion, there appears to be a link between GJH and increased flexibility, impaired balance, reduced back muscle static strength endurance, and altered posture of both feet.

Lower muscular strength is associated with greater liver fat content and higher serum liver enzymes-"The Sedentary's Liver" The Study of Health in Pomerania.

We investigated the associations of low handgrip strength (HGS, i.e., a marker of muscular fitness) with liver fat content (LFC) and serum liver enzymes in a population-based setting. We used data from 2700 participants (51.7% women), aged 21-90 years, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-START-2 and SHIP-TREND-0). Cross-sectional, multivariable adjusted regression models were performed to examine the associations of HGS with LFC, measured by magnetic resonance imaging and serum liver enzymes. We found significant inverse associations of HGS with both LFC and serum liver enzymes. Specifically, a 10-kg lower HGS was associated with a 0.59% (95% confidence interval [CI]: 0.24-0.94; p = 0.001) higher LFC, a 0.051 µkatal/L (95% CI: 0.005-0.097; p = 0.031) higher gamma-glutamyltransferase (GGT) concentration and a 0.010 µkatal/L (95% CI: 0.001-0.020; p = 0.023) higher aspartate aminotransferase (AST) concentration. The adjusted odds-ratio for prevalent hepatic steatosis (defined by a MRI-PDFF ≥5.1%) per 10-kg lower HGS was 1.21 (95% CI: 1.04-1.40; p = 0.014). When considering only obese individuals, those with low HGS had a 1.58% (95% CI: 0.18-2.98; p = 0.027) higher mean LFC and higher chance of prevalent hepatic steatosis (adjusted OR 1.74, 95% CI: 1.15-2.62; p = 0.009) compared to individuals with high HGS. We found similar associations in individuals with overweight, but not in those with normal weight. Lower HGS was strongly associated with both higher LFC and higher serum GGT and AST concentrations. Future studies might clarify whether these findings reflect adverse effects of a sedentary lifestyle or aging on the liver.

Low dietary vitamin C intake is associated with low muscle strength among elderly Korean women.

Although vitamin C is one of the most important antioxidants, its effect on muscle quality is not fully understood. Therefore, we hypothesized that low dietary vitamin C intake is associated with low muscle strength. To test the hypothesis, a single 24-h dietary recall and handgrip strength test of 10,883 younger adults 19-64 y and 3,961 older adults ≥65 y from the seventh Korea National Health and Examination Survey (KNHANES VII 2016-2018) was analyzed by multivariable linear and logistic regression models, and low muscle strength was defined as handgrip strength <28 kg for men and <18 kg for women. Approximately 15.5% of Korean adults met the recommended intake of dietary vitamin C, and those with higher dietary vitamin C intake had higher total energy and protein intake. After adjusting for confounding variables, including age, body mass index, total energy intake, household income, alcohol consumption, smoking, resistance exercise, medical condition, and dietary intake of protein, vitamin E, and ß-carotene, dietary vitamin C was correlated with maximal handgrip strength in younger women 19-64 y (ß = 0.002; SE = 0.001; P-value = .026) and older women ≥65 y (ß = 0.005; SE = 0.002; P-value = .013). Among older women ≥65 y, those in the lowest quartile of dietary vitamin C intake had a higher risk of low muscle strength compared to those in the highest quartile after adjustment of confounding factors (odds ratio, 2.16; 95% confidence interval, 1.49-3.15). These results imply that adequate dietary vitamin C intake may reduce the risk of sarcopenia in older Korean women.

The relationship between asymmetrical grip strength criteria and fall incidence among middle-aged and older Chinese adults.

PURPOSE: Current handgrip strength (HGS) protocols employ a variety of criteria, affecting the assessment of asymmetric HGS. The impact of these different criteria on fall prediction is understudied. This study was devised to compare the relative performance of average and maximum HGS asymmetry criteria as tools to predict fall incidence among middle-aged or older adults in China. METHODS: 9627 Chinese adults 50 + years of age who were participants in the China Health and Retirement Longitudinal Study (2013-2015 waves) were evaluated. The measurement of HGS was achieved based on either the maximum recorded value (HGSmax) or the average (HGSave), and these values were employed for the calculation of HGS asymmetry. Fall incidence over a 2-year period was evaluated based on self-reported data. Logistic regression analyses were utilized to determine the predictive performance of HGSmax asymmetry or HGSave asymmetry when gaging 2-year fall risk. RESULTS: Significant differences in overall rates of HGS asymmetry and the rates of subdivisions thereof were observed when comparing the HGSmax and HGSave criteria, with moderate consistency (kappa = 0.599, p < 0.001). Over the 2-year follow-up period, 1743 fall incidents were recorded. Adjusted logistic regression models indicated that only HGSmax asymmetry > 30.0% was significantly related to fall risk (p = 0.034, odds ratio = 1.36, 95% confidence interval: 1.02-1.81). CONCLUSION: These findings highlight the importance of HGS criteria in detecting HGS asymmetry, and suggest that HGSmax is a more robust criterion for predicting fall risk among Chinese adults 50 + years of age.

Using cardiorespiratory fitness to operationalize vitality: a path analysis on the hierarchical structure of intrinsic capacity.

BACKGROUND: There is a lack of consensus about the operationalization of vitality, which is one of the intrinsic capacity (IC) domains. In particular, no study has investigated whether cardiorespiratory fitness (CRF) can be considered a vitality indicator. OBJECTIVE: To examine whether vitality is the upstream domain of IC, and establish the validity of CRF as a vitality indicator, using maximal oxygen consumption (VO2 max) as a representative. METHODS: 561 older adults from a longitudinal cohort study were included. Variables under consideration were VO2 max, other IC domains, instrumental activities of daily living (IADL), and handgrip strength, which was considered an already validated indicator of vitality. Using handgrip strength as the reference point, path analyses were performed to examine whether VO2 max followed a similar hierarchical structure in predicting change in IADL difficulty through other IC domains. RESULTS: The mean age of the participants was 75.5 years. The path model in which vitality was measured by VO2 max demonstrated adequate fit, which was similar to the model in which vitality was measured by handgrip strength. Regarding the path coefficients, the model using VO2 max demonstrated significant total and indirect effects. Notably, the indirect effect was due to the locomotor domain (standardized coefficient = -0.148, p < .001), but not the cognitive or psychological domain. CONCLUSION: Vitality is the upstream domain of IC. VO2 max can be considered an indicator to operationalize the vitality concept.