Thyroid dysfunction and sarcopenia: a two-sample Mendelian randomization study.

Objective: Observational studies have shown positive associations between thyroid dysfunction and risk of sarcopenia. However, the causality of this association remains unknown. This study aimed to evaluate the potential causal relationship between thyroid dysfunction and sarcopenia using Mendelian randomization (MR). Methods: This study collected pooled data from genome-wide association studies focusing on thyroid dysfunction and three sarcopenia-related features: low hand grip strength, appendicular lean mass (ALM), and walking pace, all in individuals of European ancestry. The primary analytical method used was inverse-variance weighted, with weighted median and MR-Egger serving as complementary methods to assess causal effects. Heterogeneity and pleiotropy tests were also performed, and the stability of the results was evaluated using the Leave-one-out. Results: The MR analysis indicated that hyperthyroidism could lead to a significant decrease in ALM in the extremities (OR = 1.03; 95% CI = 1.02 to 1.05; P < 0.001). The analysis also found that hypothyroidism could cause a notable reduction in grip strength (OR = 2.03; 95% CI = 1.37 to 3.01; P < 0.001) and walking pace (OR = 0.83; 95% CI = 0.77 to 0.90; P < 0.001). There was a significant association between subclinical hyperthyroidism and a reduced walking pace (OR = 1.00; 95% CI = 0.99 to 1.00; P = 0.041). Conclusion: This study provides evidence that hyperthyroidism, hypothyroidism, and subclinical hyperthyroidism can all increase the risk of sarcopenia.

A systematic review and meta-analysis on effect of different exercise training on grip strength and upper extremity muscle strength in patients with type 2 diabetes mellitus.

BACKGROUND: Individuals with type 2 diabetes mellitus (T2DM) are prone to musculoskeletal complications, particularly in the upper extremities (UE), which can significantly impair their grip strength and UE muscle strength. This review will provide valuable insights for developing optimized exercise interventions aimed at enhancing upper limb functionality and improving patient outcomes. AIM: To determine the effect of different exercise training on grip strength & UE muscle strength in patients suffering from T2DM. METHODOLOGY: A comprehensive search from electronic databases was performed based on the selection criteria and 13 randomized controlled trials (RCT's) were included in the study. Mean changes in grip strength and UE muscle strength were the primary outcome measures. Included studies ranked high on the PEDro rating scale and eta-analysis was performed by Rev Man 5.4 software. RESULTS: Meta-analysis results indicated that there was a statistically significant improvement in UE muscle strength of experimental group when compared to control group (mean differences [MD] = 2.91, 95% confidence interval = 0.12, 5.71; p = 0.04) with moderate heterogeneity (I2 = 49%, p < 0.07). Grip strength improved significantly in the experimental group when compared to the control group with (MD = 2.93, 95% CL = -0.00, 5.86; p = 0.05) and moderate heterogeneity (I2 = 66%, p < 0.08). CONCLUSION: This review indicated a positive role of supervised resistance & aerobic exercises on UE muscle strength in patients with T2DM. Due to lack of RCT's, grip strength needs to be explored by further investigations in these patients.

Patient-Reported Outcomes Can Serve as a Functional Substitute for Grip Strength.

Background Grip strength has traditionally been seen as an objective measurement of hand function, while the Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE) has emerged recently as a common patient-reported outcome metric for similar purposes. The primary objective of this study was to determine if a correlation exists between grip strength, PROMIS UE, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores in hand and upper extremity clinic patients. Methods PROMIS UE, Pain Interference (PI), and Depression (D), as well as QuickDASH were prospectively administered to patients from July 16 to September 3, 2020. A grip strength ratio (GSR), calculated by dividing the grip strength of the injured hand by that of the noninjured hand, was recorded for each individual to control for personal differences in grip strength. Data were analyzed using Spearman's correlation coefficients with the significance level at p < 0.05. Results Fifty patients participated in this study. The median GSR was 0.55. QuickDASH demonstrated strong correlations with both PROMIS UE and PI ( r (48) = -0.81, p < 0.05; r (48) = 0.86, p < 0.05). GSR correlated moderately with PROMIS UE ( r (48) = 0.63, p < 0.05). Finally, GSR and QuickDASH also exhibited moderate correlation with each other ( r (48) = -0.62, p < 0.05). Conclusion PROMIS UE and QuickDASH are shown to correlate moderately with GSR. This suggests the PROMIS UE forms as an effective measure of hand/wrist function in hand clinic patients and may be substituted for grip strength measurements.

Effect of post COVID-19 on body composition, physical fitness, sleep quality and quality of life among young adults: a cross-sectional study of matched pairs.

Background: Coronavirus 2019 (COVID-19) causes lung tissue inflammation, affects mental health, and disturbs sleep and the musculoskeletal system. This study aimed to investigate the effects of COVID-19 on physical function and quality of life by comparing the body composition, physical fitness, sleep quality and quality of life between Thai young adults with and without post COVID-19 infection. Methods: A cross-sectional study was comprised of two matched groups (post COVID-19 group and non COVID-19 group) with 36 participants in each group. Data about body composition, physical fitness, sleep quality and quality of life were collected using the bioelectrical impedance analysis, the 1-min sit-to-stand test, the hand grip strength test, the Pittsburgh sleep quality questionnaire and the EuroQol-5D-5L, respectively. Independent samples T-test, Mann-Whitney U test and Chi-square test were used to compare between the two groups. Results: The changes in oxygen saturation and respiratory rate after the physical fitness test and the sleep quality analysis showed a statistically significant difference between the groups with and without post COVID-19 infection (p = 0.006, p = 0.003 and p = 0.003, respectively). However, quality of life and body composition were not significantly different between groups. Conclusions: COVID-19 influenced the changes in oxygen saturation and respiratory rate after the physical fitness test and the sleep quality analysis in young adults. The results should be utilized to facilitate physical rehabilitation for COVID-19-infected individuals following infection. Those who have not been infected with COVID-19 must be informed of self-protection measures to avoid contracting the virus.

Handgrip Strength and Upper Limb Anthropometric Characteristics among Latin American Female Volleyball Players.

Background: In volleyball, the upper limb dimensions and grip strength greatly influence offensive and defensive movements during a match. However, the relationship between these parameters remains underexplored in elite female volleyball players. Objective: This study aimed to contrast the upper limb anthropometric characteristics and handgrip strength (HGS) of female elite volleyball players against a control group. Methods: Selected upper limb anthropometric parameters and maximal HGS of 42 female volleyball players and 40 non-athletes were measured. Results: Players exhibited higher values in almost all variables studied than non-athletes. The differences were statistically significant (p < 0.001) except for body mass index and elbow and wrist diameters. Players showed a moderate correlation between dominant HGS and hand parameters (length r = 0.43 and breadth r = 0.63; p < 0.05). Weak correlations were identified with height, upper arm length, elbow diameter, and hand shape index (r = 0.32 to 0.38; p < 0.05). In the non-dominant hand, a moderate correlation with handbreadth (r = 0.55, p ≤ 0.01) and weak correlations with upper arm length, wrist diameter, hand length, and hand shape index (r = 0.32 to 0.35; p ≤ 0.05) was found. Conclusions: These findings underscore the importance of the upper limb anthropometric parameters as predictors of HGS and their utility in athlete selection. Future research should investigate biomechanical factors influencing HGS and injury prevention.

Association of Hormonal Exposures With Grip Strength in Women >45 Years: Data From the CONSTANCES Cohort Study.

Context: Although biological findings show that estrogens are beneficial for muscular mass maintenance and bone resorption inhibition, the association of hormonal exposure with physical performance are controversial. Objective: We investigated the association of reproductive history and exogenous hormone use with hand-grip strength (GS) in women. Methods: Using the data from the CONSTANCES French prospective population-based cohort study, we ran linear mixed models to investigate the association of reproductive history and exogenous hormones use with maximal GS in 37 976 women aged 45 to 69 years recruited between 2012 and 2020. We used multiple imputation by chained equations to control missing values and corrections for multiple testing. Results: The mean age of women was 57.2 years. Mean GS was 26.6 kg. After adjustment for age and confounders, GS increased with age at menarche (ß+1 year = 0.14; 95% CI, 0.10-0.17) and duration of breastfeeding (ß for ≥10 months vs <5 months = 0.39; 95% CI, 0.20-0.59; P for linear trend <.01). Compared to nonmenopausal women, postmenopausal women had significantly lower GS (ß = -0.78; 95% CI, -0.98 to -0.58). GS was negatively associated with hormone therapy (HT) past use (ß = -0.25; 95% CI, -0.42 to -0.07). Conclusion: Our results suggested that menopausal transition was strongly associated with lower GS. However, despite our hypothesis, increased age at menarche and duration of breastfeeding were associated with higher GS and HT past users presented lower GS than HT never users. These findings could help identify women at high risk of poor physical performance.

Comparison of Different Animal Models in Hindlimb Functional Recovery after Acute Limb Ischemia-Reperfusion Injury.

Acute limb ischemia (ALI) is a sudden lack of blood flow to a limb, primarily caused by arterial embolism and thrombosis. Various experimental animal models, including non-invasive and invasive methods, have been developed and successfully used to induce limb ischemia-reperfusion injuries (L-IRI). However, there is no consensus on the methodologies used in animal models for L-IRI, particularly regarding the assessment of functional recovery. The present study aims to compare different approaches that induce L-IRI and determine the optimal animal model to study functional limb recovery. In this study, we applied a pneumatic cuff as a non-invasive method and ligated the aorta, iliac, or femoral artery as invasive methods to induce L-IRI. We have measured grip strength, motor function, creatine kinase level, inflammatory markers such as nuclear factor NF-κB, interleukin-6 (IL-6), hypoxia markers such as hypoxia-induced factor-1α (HIF-1α), and evaluated the muscle injury with hematoxylin and eosin (H&E) staining in Sprague Dawley rats after inducing L-IRI. The pneumatic pressure cuff method significantly decreased the muscle strength of the rats, causing the loss of ability to hold the grid and inducing significant limb function impairment, while artery ligations did not. We conclude from this study that the tourniquet cuff method could be ideal for studying functional recovery after L-IRI in the rat model.

Preoperative bioelectrical impedance, measured phase angle, and hand-grip strength as predictors of postoperative outcomes in patients undergoing cardiac surgery: a systematic review.

BACKGROUND: Postoperative problems are a major danger for patients after heart surgery. Predicting postoperative outcomes for cardiac surgery is limited by current preoperative evaluations. Handgrip strength (HGS) testing and bioelectrical impedance analysis (BIA) may provide extra ways to identify individuals at risk of surgical problems, enhancing risk assessment and results. OBJECTIVE: The purpose of this systematic review is to assess the utility of measured phase angle (PA), HGS, and bioelectrical impedance as perioperative risk markers in adult patients undergoing elective heart surgery. METHOD: The PRISMA principles were followed in this review. We searched all available electronic databases, including the Science Direct search engine and PubMed, MEDLINE, EMBASE, Cochrane Library, Web of Science, PsycINFO, CINAHL, Google Scholar, Scopus, and the Science Direct search engine, from their creation to the present, as well as the medRxiv pre-print site. We considered studies with adult subjects undergoing elective heart surgery who were monitored for problems after surgery and had perioperative BIA and HGS testing. RESULTS: As a result, out of the 1544 pieces of research that were discovered, eight studies were deemed suitable for inclusion in the review and supplied data from 2781 people. The findings demonstrated a substantial correlation between poor preoperative PA and a higher risk of serious postoperative morbidity, as well as prolonged hospital stays. Furthermore, poor HGS and low PA were linked to greater death rates. Additionally, there was a strong correlation found between low PA and HGS and longer stays in the ICU, as well as an increased chance of dying from all causes in a year. In conclusion these results imply that preoperative HGS and PA may be significant indicators of postoperative results and may assist in identifying patients who are more vulnerable to problems and death.

Comparison between grip strength and relative grip strength in their relationship with allostatic load among adolescents.

PURPOSE: To assess the associations of muscle strength, measure by grip strength and relative grip strength (grip strength divided by body weight), on the allostatic load (AL) index in adolescent boys and girls. METHODS: A total of 1,323 students were recruited (boys = 776, girls = 547). Data on general demographic characteristics, anthropometric indicators, grip strength, blood pressure, pulse rate, and biological samples were collected. A 20-indicator-based AL index (using the AL1, AL2, and AL3 calculation methods) was used as the dependent variable. Multiple linear regression models were used to evaluate the association between grip strength, relative grip strength, and AL. All analyses were stratified by sex. RESULTS: The mean age of the participants was 14.17 ± 1.45 years. Overall, the linear regression model adjusting for demografic characteristics showed that greater grip strength was associated with higher AL1 scores (R2 = 10.1%, ß = 0.096, P < 0.001). Then, we further adjusted for body weight, and negative associations were observed between grip strength and AL1 (R2 = 35.3%, ß = -0.027, P = 0.030). However, after sex stratification, this association was not statistically significant in girls. Moreover, relative grip strength was negatively associated with AL1 (R2 = 14.8%, ß = -8.529, P < 0.001) after adjusting for demographic characteristics in the total sample. Specifically, relative grip strength was more strongly associated with the AL1 burden in boys than in girls. Finally, sensitivity analyses of AL2 and AL3 yielded similar results. CONCLUSION: We observed that compared with grip strength, relative grip strength might be a useful indicator for the identification of AL burden in adolescents. The results suggest that strengthening relative handgrip strength in adolescents might help reduce the AL burden, especially in boys.

Effect of a smartphone-based physical intervention on depression, fitness factors and movement characteristics in adults.

BACKGROUND: Physical activity has been shown to correlate with mental health and a reduction in symptoms of depression. However, the majority of research has focused only on the effects of either aerobic or nonaerobic exercise on depressive symptoms, while the use of novel technological innovations such as mobile phone-based activity programs and their effects on movement characteristics are underrepresented. This study had two objectives: (1) to investigate how effectively 4 weeks of mobile phone-based physical activity can affect depressive scores (CES-10-D and PHQ) and fitness levels and (2) to investigate the whether 4 weeks of mobile phone-based physical activity affected participants' movement characteristics. METHODS: A total of 31 participants were included and divided into an exercise group (n = 21) and a control group (n = 10). The exercise group was instructed to use a mobile phone-based exercise program 5 times per week for 4 weeks. Pre- and post-exercise, the participants' depression score (CES-10-D, PHQ9), fitness level (YMCA, grip strength) and movement characteristics (postural sway, movement ROM, movement speeds, etc.) for three Azure Kinect physical activity games based on different fitness factors (balance game, cardiovascular game, reaction game) were measured. RESULTS: Mixed model ANOVA revealed significant differences between pre- and post-intervention depression scores on the PHQ9 (P = .001) and CES-10-D (P < .001) in both the exercise group and the control group, but not between groups. In terms of movement characteristics, there was an increase in body sway (P = .045) and vertical head movement (P = .02) in the cardiovascular game jogging condition for the exercise group. In the reaction game, the exercise group showed a significant reduction in the number of mistakes (P = .03). There were no other significant differences for the other variables. CONCLUSION: The results revealed no differences in the reduction in depression scores between the exercise group and the control group. However, this study showed that a mobile phone-based physical activity intervention affects in-game movement characteristics such as body sway and vertical head movement and therefore may show the potential of using activity-promoting mobile games for improving movement.

Low hand grip strength as an indicator of depression in the Korean population: a large-scale cross-sectional study.

Background: Depression is one of the leading global mental health problems, and hand grip strength (HGS) is associated with depression. However, there have been no studies assessing the association between depression and relative HGS indices combined with waist circumference (WC) and the waist-to-height ratio (WHtR). The objective of this study was to examine the association of depression with absolute and relative HGS indices. Methods: This was a cross-sectional study based on the Korea National Health and Nutrition Examination Survey from 2014 to 2019. A total of 20,649 participants (8,959 men, 43.4% and 11,690 women, 56.6%) were included. The associations between depression and the HGS indices were analyzed through complex sample binary logistic regression models, which were adjusted for age in Model 1 and various covariates in Model 2. Results: The prevalence of depression was 4.58%, with rates of 2.29% for men and 6.34% for women. The prevalence of depression in women was 2.76 times greater than that in men. In men, the mean HGS values in the dominant hand were 35.48 ± 0.75 kg in the depression group and 38.73 ± 0.11 kg in the non-depression group; in women, they were 21.37 ± 0.22 kg in the depression group and 22.77 ± 0.07 kg in the non-depression group. In men, relative HGS indices as HGS/WC, HGS/body mass index, and HGS/WHtR were more strongly associated with depression than were the absolute HGS indices; however, in women, the associations were similar for both absolute and relative HGS indices. The magnitude of the association was greater for men than for women. In both sexes, all the anthropometric indices had a lower association with depression than did the HGS indices. Conclusion: Low absolute and relative HGS were negatively associated with depression in the Korean population. But, relative HGS indices were more strongly associated with depression than were absolute HGS and anthropometric indices in men but not in women.

Association between grip strength, walking pace and incident peripheral artery disease: A prospective study of 430,886 UK biobank participants.

Background and aims: Patients with peripheral artery disease (PAD) presented overall muscle weakness and reduced physical performance. Previous study focused on the impact of muscle weakness on outcomes of established PAD, however the relationship between compromised muscle function and incident PAD remained unclear. Methods: A prospective study involving 430,886 participants aged 40-69 y from UK biobank was conducted. The main outcome was incident PAD. Grip strength and walking pace were used as indicators for muscle function. Grip strength was measured using a Jamar J00105 hydraulic hand dynamometer, while walking pace was self-reported by the participants. Cox proportional hazard models were employed to investigate the relationship between grip strength, walking pace, and incident PAD. Results: A total of 430,886 individuals were included in the final analysis. The mean age of the participants were 56.44 years, and 55.3 % were female. Over a median follow-up period of 13.81 years, 5,661 participants developed PAD. Higher grip strength, whether absolute or relative, exhibited a dose-dependent inverse association with incident PAD. Each 1 kg increment in absolute grip strength and each 0.01 kg/kg increase in relative grip strength were associated with reduced PAD risk by 2 % (HR: 0.98; 95 % CI [0.97-0.98]) and 83 % (HR: 0.17; 95 % CI [0.13-0.23]), respectively. Slow walking pace significantly correlated with increased PAD risk, while brisk walking pace was associated with decreased PAD risk. Conclusion: Absolute grip strength, relative grip strength and walking pace were inversely associated with the risk of incident PAD.

High-density lipoprotein cholesterol level and risk of muscle strength decline and sarcopenia in older adults.

BACKGROUND: Recent studies have demonstrated that very high high-density lipoprotein cholesterol (HDL-C) level was paradoxically linked with higher risk of cardiovascular mortality, all-cause mortality, and several age-related diseases. However, whether very high HDL-C level is associated with a higher risk of sarcopenia in older adults remains unclear. We aimed to investigate the association between HDL-C level and the risk of developing sarcopenia and low grip strength over time in older adults. METHODS: Participants were from the ongoing China Health and Retirement Longitudinal Study (CHARLS), which includes a nationally representative sample of adults aged ≥45 years and was performed from 2011 to 2020 with follow-ups every two to three years. The current study included 4031 participants aged ≥60 years. Muscle health-related data were collected in waves 2011, 2013, and 2015. Based on HDL-C level at baseline, participants were categorized into five groups: <35 mg/dl, 35-40 mg/dl, 40-60 mg/dl, 60-70 mg/dl and >70 mg/dl. The main outcomes were incident sarcopenia and incident low grip strength over follow-up. Low grip strength and sarcopenia were defined according to the 2019 Consensus by the Asian Working Group for Sarcopenia. Cox proportional-hazard regression was performed to investigate the association between HDL-C level and the risk of developing sarcopenia and low grip strength in older adults. RESULTS: The mean age of study sample was 67.3 (SD 6.1) years, and 49.6% were male. During an average 3.7-year follow-up, 409 (10.1%) participants developed sarcopenia and 771 (21.1%) developed low grip strength. Non-linear association was observed between HDL-C level and the hazard of developing sarcopenia and low grip strength. The multivariable model showed that compared to the reference group (40-60 mg/dl), older adults with very high HDL-C level (>70 mg/dl) had a significantly higher risk of developing sarcopenia (HR 1.69, 95% CI 1.28-2.23) and low grip strength (HR 1.23 95% CI 1.00-1.51). Stratified analyses by sex revealed similar association. CONCLUSIONS: We present the first longitudinal evidence that very high HDL-C level was associated with a significantly higher risk of muscle strength decline and developing sarcopenia in older adults. It is essential to monitor the muscle health of older adults with very high HDL-C level in clinical practice.

Normative Data of Grip Strength and Pinch Strength in the Indian Population.

Background There is no normative study of transregional grip strength data available from India. Hence, a multicenter study is designed to obtain reference value. Materials and Methods This is a prospective observational study conducted as a part of the Indian normative data project of the Indian Society for Surgery of the Hand. The study included three participating centers: one from the northern part and two from the southern part. Certified calibrated Jamar dynamometer and Jamar pinch gauge were used to measure the grip strength, key pinch strength, tip pinch strength, and tripod pinch strength as per the guidelines of the American Society of Hand Therapists. Results A total of 1,019 volunteers in the age group of 18 to 60 years were studied. The mean grip strength in males and females was 38.18 and 24.06 kg, respectively. The mean key pinch strength was 8.52 kg in males and 5.97 kg in females. The mean tip pinch strength was 4.86 kg in males and 3.59 kg in females. The mean tripod pinch strength was 5.41 kg in males and 4.16 kg in females. Conclusions All four strengths were lower in value when compared with American and other populations. The men had more strength than women. There was no relation to hand dominance. There was a correlation for age and height but no correlation with body mass index (BMI).

Mendelian randomization analysis reveals no causal relationship between thyroid function and sarcopenia-related traits.

Background: Recent research has indicated a potential association between thyroid function and sarcopenia, but the specific mechanisms and a definitive causal relationship have yet to be established. Therefore, the objective of this study is to examine the potential causal connection between thyroid function and sarcopenia-related traits, including hand-grip strength, appendicular lean mass (ALM), and walking pace. Methods: The study used a bi-directional two-sample MR design, with thyroid function examined as the exposure and sarcopenia-related traits as the outcome in the first stage, and then reversed in the second stage. The genetic instruments for thyroid function were obtained from a comprehensive meta-analysis involving 271,040 participants. Data on sarcopenia-related traits based on GWASs were collected from the UK Biobank, which includes up to 461,026 European participants. The estimates for MR were calculated using the inverse-variance weighted (IVW) method, and several sensitivity analyses were performed. Results: After applying the Bonferroni correction for multiple testing, our MR analyses revealed no significant impact of thyroid function liability on sarcopenia-related traits. Similarly, our reverse MR analysis did not provide evidence supporting the influence of liability to sarcopenia-related traits on thyroid function. The results of the primary IVW MR analyses were largely in line with those obtained from our sensitivity MR analyses. Conclusion: Our research findings do not suggest a link between thyroid function and sarcopenia-related traits. The associations identified in epidemiological studies may be influenced, at least in part, by shared biological mechanisms or environmental confounders.

Sarcopenia and frailty among the elderly population in the community: An observational study.

Context: There are few studies on the prevalence of sarcopenia and frailty in India. Aims: The aim of this study was to assess sarcopenia and frailty using simple clinical tools among the elderly population in the community. Settings and Design: This was an observational study. The elderly population with an age group of >60 years residing in villages within 10-15 km of Sumandeep Vidyapeeth, Vadodara, formed the sampling frame of the study. Methods and Material: A total of 785 participants were approached, of whom 556 were included in the study based on inclusion criteria. Participants were assessed for grip strength, muscle mass, gait speed, and frailty. Statistical Analysis Used: The data were analyzed using STATA-IC statistical software version 13. A nonparametric Chi-square (χ2) test was used for categorical variables, and an independent-samples t-test was used to analyze the difference between various variables. Statistical significance was considered at P < 0.05 with a 95% confidence interval (CI). Results: Based on the Indian criteria, 205 participants (36.1%) were diagnosed as having sarcopenia, and 351 participants (63%) were diagnosed as having "no sarcopenia." 5.6% of participants were found to be frail, 19.2% to be pre-frailty, and 75.2% to be no frailty. The χ2 analysis showed a significant association of sarcopenia with gender and different age groups (P value < 0.001). Conclusions: In this study, 36.9% of the elderly participants were found to have "sarcopenia," and 5.6% of the participants had frailty. Simple clinical tools used were easy to administer and suitable for field screening.

The effect of non-pathological neck pain on hand grip strength in healthcare practitioners across three different head positions: a cross-sectional study design.

[Purpose] To determine how different head-neck positions (HNPs) influence the hand grip strength (HGS) of medical personnel with non-pathological neck pain (NPNP). [Participants and Methods] A cross-sectional study recruited 46 healthcare professionals: 21 (45.7%) with NPNP and 25 (54.3%) without. A dynamometer, cervical range of motion, and visual analogue scale measured HGS, HNPs, and NPNPs. Participants were instructed to squeeze the handgrip dynamometer handle in 90-degree elbow flexion as much as possible from a seated position to measure HGS from the neutral head position (NHP), 40° head neck flexion (HFP40°), and 30° head neck extension (HEP30°). [Results] The mean HGS for the dominant hand in NHP, HFP40°, and HEP30° was 29.27 kg (± 9.03), 27.24 kg (± 9.08), and 26.37 kg (± 9.32), while for the non-dominant hand it was 27.45 kg (± 9.62), 25.23 kg (± 9.36), and 24.61 kg (± 10.17). There was no significant correlation between HNPs and HGS. However, the only significant difference was between dominant HGS in the NHP and non-dominant HGS in the HEP30°. [Conclusion] NPNP had no significant influence on HGS in any of the three HNPs for either hand. Future studies should include other HNPs and other potential variables such as age, gender, weight, and pain intensity.

Pharmacological Doses of Thiamine Benefit Patients with the Charcot-Marie-Tooth Neuropathy by Changing Thiamine Diphosphate Levels and Affecting Regulation of Thiamine-Dependent Enzymes.

Charcot-Marie-Tooth (CMT) neuropathy is a polygenic disorder of peripheral nerves with no effective cure. Thiamine (vitamin B1) is a neurotropic compound that improves neuropathies. Our pilot study characterizes therapeutic potential of daily oral administration of thiamine (100 mg) in CMT neuropathy and its molecular mechanisms. The patient hand grip strength was determined before and after thiamine administration along with the blood levels of the thiamine coenzyme form (thiamine diphosphate, ThDP), activities of endogenous holo-transketolase (without ThDP in the assay medium) and total transketolase (with ThDP in the assay medium), and transketolase activation by ThDP [1 - (holo-transketolase/total transketolase),%], corresponding to the fraction of ThDP-free apo-transketolase. Single cases of administration of sulbutiamine (200 mg) or benfotiamine (150 mg) reveal their effects on the assayed parameters within those of thiamine. Administration of thiamine or its pharmacological forms increased the hand grip strength in the CMT patients. Comparison of the thiamin status in patients with different forms of CMT disease to that of control subjects without diagnosed pathologies revealed no significant differences in the average levels of ThDP, holo-transketolase, or relative content of holo and apo forms of transketolase. However, the regulation of transketolase by thiamine/ThDP differed in the control and CMT groups: in the assay, ThDP activated transketolase from the control individuals, but not from CMT patients. Thiamine administration paradoxically decreased endogenous holo-transketolase in CMT patients; this effect was not observed in the control group. Correlation analysis revealed sex-specific differences in the relationship between the parameters of thiamine status in both the control subjects and patients with the CMT disease. Thus, our findings link physiological benefits of thiamine administration in CMT patients to changes in their thiamine status, in particular, the blood levels of ThDP and transketolase regulation.

Circulating inflammatory cytokines and sarcopenia-related traits: a mendelian randomization analysis.

Objective: To explore the causal relationships between 91 circulating inflammatory cytokines and sarcopenia-related traits (low hand grip strength, appendicular lean mass, and usual walking pace) by Mendelian randomized analysis. Methods: Independent genetic variations of inflammatory cytokines and sarcopenia-related traits were selected as instrumental variables from publicly available genome-wide association studies (GWAS). The MR analysis was primarily conducted using the inverse variance-weighted (IVW) method. Sensitivity analyses included Steiger filtering and MR PRESSO, with additional assessments for heterogeneity and pleiotropy. Results: The IVW method indicated a causal relationship between Vascular Endothelial Growth Factor A (VEGF-A) and low hand grip strength (OR = 1.05654, 95% CI: 1.02453 to 1.08956, P = 0.00046). Additionally, Tumor Necrosis Factor-beta (TNF-ß) was found to have a causal relationship with appendicular lean mass (ALM) (ß = 0.04255, 95% CI: 0.02838 to 0.05672, P = 3.96E-09). There was no evidence suggesting a significant causal relationship between inflammatory cytokines and usual walking pace. Conclusion: Our research substantiated the causal association between inflammatory cytokines, such as VEGF-A and TNF-ß, and sarcopenia. This finding may provide new avenues for future clinical treatments.