Association between grip strength and bone mineral density in general US population of NHANES 2013-2014

Enhancing osteoporosis risk prediction using machine learning: A holistic approach integrating biomarkers and clinical data

Osteoporosis (OP) affects approximately 18 % of the global population, with osteoporosis-associated fractures impacting up to 37 million people annually. While dual-energy X-ray absorptiometry (DXA) remains the gold standard for diagnosis, its limitations, including restricted availability and radiation exposure, highlight the need for alternative screening methods. We developed a machine learning model to predict OP risk using routinely collected clinical data, deliberately excluding DXA measurements to ensure broad accessibility. Using data from NHANES cycles 2007-2014, we analyzed 7924 participants aged 50 years and older, identifying 1636 OP cases (20.6 %) and 6288 normal cases (79.4 %) through comprehensive criteria incorporating both WHO densitometric standards (T-scores ≤ -2.5) and anthropometric risk factors. We implemented a stacking ensemble model combining four specialized classifiers (Gradient Boosting, Random Forest, XGBoost, and LightGBM) with a logistic regression meta-classifier. The model achieved 93 % accuracy, an AUC of 0.94, and demonstrated robust performance through cross-validation (mean score: 0.929 ± 0.030). feature importance analysis revealed age (6.04 %), arm muscle circumference (5.61 %), and body weight (5.30 %) as the most influential predictors, followed by gender (3.28 %), BMI (2.71 %), and calcium intake (2.42 %). Additional significant predictors included folate (2.28 %), height (2.23 %), hand grip strength (2.21 %), and alkaline phosphatase (2.16 %). These biologically plausible relationships align with established clinical knowledge of OP risk factors. The model's strong performance metrics and reliance on readily available clinical data suggest its potential as a practical screening tool, particularly in settings with limited DXA access. All code and implementation details are openly available on GitHub, facilitating integration into existing healthcare systems. This approach offers a promising pathway for enhancing early OP detection and risk assessment across diverse healthcare settings.

Assessing bone and muscle health and their association in a Mongolian population aged 40 and older: a pioneering observational study

This study in Mongolia reveals that weaker grip strength and higher sarcopenia risk are linked to greater fracture risk and lower bone density. It highlights the crucial interplay between muscle and bone health, emphasizing the need for integrated musculoskeletal assessments to prevent fractures, especially in aging populations.

BACKGROUND

Research on the relationship between bone and muscle health in low- and middle-income countries, particularly Central Asia, remains limited.

OBJECTIVES

To explore the correlation between muscle and bone health and to estimate the FRAX risk for major osteoporotic fractures (MOF) and hip fractures in the Mongolian population, stratified by age and sex.

METHODS

A cross-sectional study was conducted in Ulaanbaatar and regional Mongolia from May to August 2024. Handgrip strength, sarcopenia risk (SARC-F) and bone mineral density using peripheral DXA (BMD T-score) were assessed. Fracture risks were estimated using the FRAX model.

RESULTS

Participants (n = 857; median age, 52 years; 53.0% women) had a median grip strength of 28 kg and a median BMD T-score of - 1.9. Most (69.5%) were at low sarcopenia risk (SARC-F < 4). SARC-F was moderately correlated with FRAX scores for MOF and hip fractures (r ≈ 0.27, p < 0.001) while grip strength was negatively correlated with FRAX scores(r =  - 0.24, p < 0.001). Grip strength positively correlated with BMD T-scores (r = 0.22, p < 0.001). Fracture risks increased with age, with women showing higher rates than men. Higher sarcopenia risk (SARC-F ≥ 4) was associated with lower BMD and increased fracture risk. Lower grip strength (< 18 kg for women, < 28 kg for men) was linked to higher fracture risk and lower BMD.

CONCLUSIONS

This study highlights the interconnected nature of muscle and bone health in the Mongolian population, demonstrating that lower grip strength and higher sarcopenia risk are significantly associated with increased fracture risk and reduced bone density. These findings underscore the importance of integrated strategies for musculoskeletal health assessment and fracture prevention, particularly in aging populations.

Effect of different types of exercise on bone mineral density in postmenopausal women: a systematic review and network meta-analysis

Postmenopausal women (PMW) experience the decline of ovarian function; estrogen reduction will accelerate bone mass loss. Exercise is an effective means of mitigating bone mineral density (BMD) loss in PMW, but the relative effectiveness of different exercise types remains under investigation. Our study encompassed a thorough assessment and network meta-analysis, following the principles specified in the Preferred Reporting Items for Systematic Reviews and Network Meta-analysis (PRISMA) statement. Data sources and searches Literature search databases include PubMed, Embase, Cochrane, Google Scholar, Web of Science (WOS), and Scopus. The data search combined keywords like bone mineral density (BMD), postmenopausal women, and various exercise types. Data synthesis and analysis Perform a network meta-analysis by integrating both direct and indirect comparisons using the R environment. This network meta-analysis aimed to evaluate and compare various exercise types with bone mineral density in PMW to identify the most effective types. The literature comprised a collective of 49 papers, encompassing 3360 people across eight interventions. The Network Meta-analysis ranked the effects of exercise interventions on lumbar spine BMD in descending order, based on the p-scores assigned to them in the forest plot. The exercise modalities that showed significant efficacy were AE + RT(Aerobic Mixed Resistance Exercise, MD = 32.35, 95% CrI [8.08;56.62], p = 0.87), AE(Aerobic Exercise, MD = 22.33, 95% CrI [6.67;37.99], p = 0.74), and RT(Resistance Training, MD = 16.98, 95% CrI [8.98;24.99], p = 0.60). Similarly, the femoral neck sites were ranked in descending order based on their p-scores in the forest plot, and the exercise patterns with significant effects on lumbar spine bone mineral density were AE + RT(MD = 140, 95% CrI [40.89;239.11], p = 0.99), WBV(Whole Body Vibration, MD = 26.07, 95% CrI [2.97;49.16], p = 0.80), and RT(MD = 16.98, 95% CrI [8.98;24.99], p = 0.72). Exercise intervention significantly and effectively alleviated BMD in postmenopausal women, with AE + RT having the best effect.

Adult Cervical Deformity Patients Have Higher Baseline Frailty, Disability, and Comorbidities Compared With Complex Adult Thoracolumbar Deformity Patients: A Comparative Cohort Study of 616 Patients

STUDY DESIGN

Multicenter comparative cohort.

OBJECTIVE

Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery.

METHODS

Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts.

RESULTS

616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS (P < .001).

CONCLUSIONS

Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization.

The genetic causal effect of hand grip strength on osteoporosis and falling risk: a Mendelian randomization study

Background

Patients with osteoporosis (OP) are often associated with decreased hand grip strength and increased risk of falling. It remains unclear whether there is a genetic causal between hand grip strength and OP, falling risk.

Methods

The Mendelian randomization study was used to investigate the genetic causal effect of low hand grip strength on total body bone mineral density (BMD) at different ages, OP, and falling risk. Genes for low hand grip strength, total body BMD at different ages, OP, and falling risk were obtained from published genome-wide association studies. Inverse variance weighted, MR-Egger, and weighted median were applied to perform the MR analysis. The Cochran's Q test, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out analysis were used to detect the pleiotropy or heterogeneity.

Results

The results showed strong evidence that low hand grip strength was positively associated with OP (OR: 1.006, 95% CI: 1.003-1.010; P= 0.0001) and falling risk (OR: 1.069, 95% CI: 1.013-1.129; P= 0.0160), and could not directly affect the different ages of total body BMD (P> 0.05). There was no heterogeneity or horizontal pleiotropy in the sensitivity analysis (all P> 0.05).

Conclusion

The study found a positive causal relationship between low hand grip strength and higher risk of OP and falling, which should be taken into account in the development of future prevention and screening strategies for OP and falling.

Mendelian randomization study on association between grip strength and BMD in different age groups

INTRODUCTION

This study aimed to use the Mendelian randomization study method to verify the causal relationship between grip strength and bone mineral density (BMD) in different ages and different parts of the body.

MATERIALS AND METHODS

The analysis was based on pooled data from genome-wide association studies (GWAS). Hand grip strength (right) was used as the exposure variable and total body bone mineral density (BMD) of different age groups was used as the outcome variable. Single-nucleotide polymorphisms highly correlated with exposure variables were used as instrumental variables. The inverse variance weighted (IVW) method was used as the primary analysis method, and the Mendelian randomization Egger (MR-Egger) regression and weighted median methods were used as supplementary evidence for the IVW results. Horizontal pleiotropy and heterogeneity tests were conducted to ensure the stability of the results.

RESULTS

Analyzing the GWAS data on osteoporosis as the outcome variable, the IVW analysis showed that osteoporosis risk was associated with decreased grip strength in the 45-60 age group and the risk of declining lumbar spine BMD was associated with decreased grip strength. However, there was no significant correlation between the risk of osteoporosis in other age groups and changes in grip strength.

CONCLUSION

A causal relationship exists between decreased grip strength and osteoporosis risk in people aged 45-60 years. The risk of BMD declining in the lumbar spine was associated with reduced grip strength.

Effects of Frailty Syndrome on Osteoporosis, Focusing on the Mediating Effect of Muscle Strength and Balance in Community-Dwelling Older Adults (≥60 years) in Iran: Results From the Amirkola Health and Aging Project Cohort Study

Introduction

For older adults, maintaining muscle strength and balance is crucial to preserve an upright posture and independently manage their basic activities of daily living (ADL). This study aimed to examine whether muscle strength and balance mediate the relationship between frailty syndrome (FS) and osteoporosis in a large sample of community-dwelling older adults.

Material and Methods

This cross-sectional study is part of the second phase (2016-2017) of the Amirkola Health and Ageing Project (AHAP), a cohort study conducted on all elderly aged 60 and over in Amirkola, Northern Iran, since 2011. Data from 2018 older adults were collected by a trained person using bone mineral density (BMD), frailty index, activities of daily living (ADL), instrumental activities of daily living (IADL), handgrip strength (HGS), quadriceps muscle strength (QMS), Berg Balance Scale (BBS), and Timed Up and Go test (TUG test) and analyzed using analysis of variance, chi-square, and path analysis tests.

Results

The mean indices of femoral neck BMD and lumbar spine BMD, HGS, QMS, BBS, ADL, and IADL were lower in the frail older adults than in the pre-frail and non-frail older adults. In addition, the mean TUG test level was higher in the frail older adults than in the non-frail and pre-frail older adults. The results of the present study have indicated that frailty is significantly related to osteoporosis, and that balance and muscle strength can predict osteoporosis; these variables play a mediating role in the relationship between frailty and osteoporosis.

Conclusion

From the results of the present study, it can be concluded that frailty may increase the odds of osteoporosis. The results of the current study have indicated that balance (BBS and TUG test) and muscle strength (HGS and QMS) are associated with osteoporosis and these variables play a mediating role in the relationship between frailty and osteoporosis.

Risk factors for decreased bone mineral density in patients with metabolic dysfunction-associated steatotic liver disease: A cross-sectional study at a health examination center

BACKGROUND & AIMS

Steatotic liver disease (SLD) is often detected in health examinations. However, although individuals with metabolic dysfunction-associated SLD (MASLD) may have decreased bone mineral density (BMD), the specific risk factors remain unclarified. The objective of this study was to identify the factors associated with decreased BMD in patients with MASLD.

METHODS

Individuals who underwent abdominal ultrasonography and BMD measurements at our healthcare center were included. The BMD of the calcaneus was assessed using an AOS-10SA bone densitometer. Decreased BMD was defined as a T-score below -1.0 SD or the administration of osteoporosis treatment. SLD was diagnosed based on specific ultrasonographic criteria.

RESULTS

A total of 1410 patients were diagnosed with MASLD. The median age was 52 years. Multivariate analysis using a logistic regression model revealed that the independent predictors of decreased BMD were a low body mass index (BMI) or a small waist circumference (odds ratio (OR): 0.48, 95% confidence interval (CI): 0.34-0.67), hypertriglyceridemia (OR: 1.29, 95% CI: 1.00-1.65), and a weak grip strength (OR: 0.98, 95% CI: 0.97-1.00). Subgroup analyses of individuals aged 50 years or older, men, and individuals with a FIB-4 index of 1.3 or greater revealed that the absence of a high BMI or a large waist circumference was associated with decreased BMD. The subgroup analysis of men revealed that a weaker grip strength was associated with decreased BMD.

CONCLUSION

The present study suggested several potential risk factors for decreased BMD in patients with MASLD. Individuals with the abovementioned risk factors should be encouraged to undergo BMD measurement from the perspective of preventive medicine.

Predictors of Hand Grip Strength in Adults Without Sarcopenia: Data From the NHANES, 2013-2014

Background

Grip strength measurement is used to estimate muscle strength and predict health status; yet, an accurate examination of grip strength predictors from body composition variable is lacking.

Objectives

This study aimed to examine the association of grip strength with lumbar bone mineral density (BMD) and total lean mass in adults without sarcopenia.

Methods

Adults without sarcopenia (N = 3100) were included from the NHANES, 2013-2014, in this cross-sectional study. Body mass (kg), body height (cm), body mass index (kg/m2), grip strength (kg), total percent fat (%), lumbar BMD (g/cm2), and total lean mass excluding bone mineral content (BMC, kg) were obtained and tested as predictors of grip strength.

Results

The regression analysis yielded a significant model [F(2,343732) = 71,284.2; R2 = 0.713; P < 0.001], with all predictors explaining ∼71.3% of the variance in grip strength. Age [β: -0.043; 95% confidence interval (CI): -0.040, -0.036], sex (β: -0.296; 95% CI: -6.431, -6.270), total percent fat (β: -0.245; 95% CI: -0.315, -0.308), lumbar BMD (β: 0.037; 95% CI: 2.529, 2.806), and total lean mass (β: 0.482; 95% CI: 0.001, 0.001) were all significant predictors of grip strength.

Conclusions

The predictive value of the BMD and total lean mass can serve as a useful measure in predicting grip strength and overall health status in adults without sarcopenia.

Association between grip strength and albuminuria in the general United States population: NHANES 2011-2014

Background

Grip strength has been shown to be associated with chronic renal insufficiency, but the relationship between grip strength and albuminuria has not been confirmed. In this study, we used NHANES data to explore the association between grip strength and albuminuria in a US population.

Methods

In this analytical study, we utilized data sourced from the National Health and Nutrition Examination Survey (NHANES), specifically spanning the years 2011 to 2014. The dataset included 9,638 participants aged 20 years or older. After adjusting for potential confounders, multiple regression models were developed to infer the interrelationship between grip strength and albumin to creatinine ratio (ACR), and subgroup analyses were conducted.

Results

After adjusting for all covariates, ACR by 0.49 mg/g [-0.49 (95% CI: -0.93, -0.04)] for each 1 kg increase in grip strength decreased. Subgroup analysis showed that gender, age, hyperlipidemia, hypertension, diabetes mellitus, smoking, alcohol consumption and body mass index did not influence the negative correlation between grip strength and albuminuria.

Conclusion

There is a negative correlation between grip strength and albuminuria in the general U.S. population.

Exploring the impact of short daily haemodialysis on muscle strength and bone health in end-stage kidney disease patients

BACKGROUND

Short-daily haemodialysis (SDH) has been strongly recommended over conventional haemodialysis (CHD) for end-stage kidney disease patients, though few studies have directly compared the effects of these two haemodialysis (HD) modalities on clinical variables related to patient's health.

METHODS

We conducted a cross-sectional study in individuals undergoing HD, comparing epidemiological, clinical, metabolic, inflammatory, anthropometric, bone health/metabolism, and skeletal muscle function according to dialysis modality. One-hundred seventy-eight patients (20.8% females, 62 ± 2.5 years old), were analysed in this study, 86 (48%) of whom were undergoing CHD versus 92 (51%) who were undergoing SDH.

RESULTS

SDH patients had significantly higher serum albumin levels (3.93 vs. 3.66 g/dL, P < 0.0001) and higher Kt/v (2.6 vs. 2.38, P < 0.0001). SDH group presented a significantly lower number of erythropoietin-stimulating agents compared with CHD group (percentage: 53.3 vs. 83.7%, P < 0.0001) and had lower levels of serum phosphate (4.9 vs. 5.3 mg/dL, P = 0.004) and parathyroid hormone (PTH) (398.4 vs. 480.4 pg/mL, P < 0.001) compared with CHD patients. In terms of bone health and metabolism, SDH patients had significantly higher total BMD, femur BMD, lumbar BMD, and femoral neck BMD compared with CHD patients (all P < 0.05). SDH patients also had lower anti-osteogenic and inflammatory biomarkers, including FGF23, sclerostin, TNF, IL-18, IL-17a, and C-reactive peptide (all P < 0.05). CHD modality was demonstrated to be a risk factor for low BMD (odds ratio: 4.02; 95% CI: 1.59-10.2, P = 0.003). In terms of skeletal muscle function, SDH patients had significantly higher 6-minute walking test (444.6 vs. 424.9 m, P = 0.04) and higher fat-free mass (52.3 vs. 51.68 kg, P = 0.02) compared with CHD patients. Higher fat-free mass and handgrip strength were associated with a 34% and 23% lower risk of low BMD, respectively. SDH patients had lower levels of the uremic toxin asymmetric dimethyl-l-arginine (ADMA) (1.8 vs. 2.07 μM, P = 0.002) and fasting blood glucose (132.6 vs. 141.7 mg/dL, P < 0.02) than CHD group. SDH patients also displayed higher levels of haemoglobin when compared with CHD group (11.9 vs. 10.2 g/dL, P < 0.0001).

CONCLUSIONS

The present study improves our understanding of the relationship between dialysis modality and clinical variables that may influence HD patient's health. Grip strength and lean mass were positively correlated with bone mineral density in HD patients regardless of dialysis modality. SDH was associated with better bone mineral density, inflammatory profile, and skeletal muscle function when compared with CHD patients. These findings provide more evidence of the clinical benefits of SDH that should be explored in greater detail.

Hand Grip Strength, Osteoporosis, and Quality of Life in Middle-Aged and Older Adults

Background and Objectives: Hand grip strength (HGS) and osteoporosis are known to be closely related to the health condition of the elderly, respectively. Comprehensive studies including adults over middle age were insufficient. This study aimed to investigate the relationship between HGS with osteoporosis and health-related quality of life (HRQoL) in adults aged >40 years. Materials and Methods: This cross-sectional analysis included data from 13,966 people aged >40 years between 2015 to 2018 provided by the Korea National Health and Nutrition Examination Survey. The HGS was divided into strong and weak quartiles, defined as the highest and lowest quartiles, respectively. We used the European Quality of Life Scale-Five dimensions (EQ-5D) for HRQoL. We performed multiple logistic regression and post hoc analysis to confirm the relationship between the four groups and HRQoL. Results: Osteoporotic patients with weak HGS showed the lowest EQ-5D index (0.87 ± 0.01) among all groups and had a significantly impaired HRQoL in all EQ-5D dimensions, at least 1.75 times more than healthy individuals with strong HGS (0.95 ± 0.00). Osteoporotic patients with weak HGS showed, notably, 2.68 times more impaired mobility compared to healthy individuals with strong HGS among all five dimensions of the EQ-5D. In self-care, significant sex differences in impaired HRQoL were observed (males 6.03, 2.23-16.35; females 2.51, 1.70-3.71). Conclusions: Weak HGS and the presence of osteoporosis were associated with low HRQoL, respectively. Middle-aged and older adults with both weak HGS and osteoporosis showed poorer HRQoL compared to healthy middle-aged and older adults. This suggests that HGS is a possible factor for predicting poor HRQoL in adults aged >40 years with or without osteoporosis. It is necessary to assess the risk of low HRQoL by measuring HGS and confirming whether osteoporosis is accompanied in adults over middle age.

Muscle quality is negatively related to hypertension prevalence in adults: Results from NHANES 2011-2014

Resistance training could counter hypertension and improve muscle quality (MQ), but current evidence about the correlation between MQ and hypertension is limited. The authors aimed to explore this correlation using the data of participants aged 20-59 from NHANES 2011-2014 via a cross-sectional study. The MQ was quantified as handgrip strength (kg)/lean soft tissue mass (kg) of the dominant arm. Weighted multivariate logistic regression models were mainly utilized to investigate the MQ-hypertension association; linear trend tests and subgroup analysis were also conducted. Moreover, the authors employed weighted multivariate linear regression models to uncover the association between blood pressure (BP) and MQ. Four thousand four hundred and sixty-nine individuals were enrolled, and 1167 were hypertensive. Hypertensive participants had a lower MQ than normotensive participants. In the totally adjusted model, each unit elevation in MQ was related to a 7% reduction in hypertension prevalence (p =.002). There was a decreasing trend in hypertension prevalence and in systolic BP as the MQ increased from the bottom to the top quartile across all three models (p for trend ≤.01), with a 28% difference (OR: 0.72, 95% CI: 0.54, 0.95) in hypertension prevalence and a 1.88 mm Hg (95% CI: -3.56, -0.20) difference in SBP between the top and bottom quartiles in the fully adjusted model. Subgroup analysis further confirmed the MQ-hypertension inverse association. In conclusions, the MQ was negatively associated with hypertension prevalence and systolic BP, which suggests the MQ may be a protective factor for hypertension and need to be improved.

Hand grip strength, vitamin D status, and diets as predictors of bone health in 6-12 years old school children

BACKGROUND

Vitamin D and calcium-rich foods, exposure to sunlight, and physical activities (PA) play a pivotal role in promoting the production of sufficient vitamin D and improving grip strength needed for better bone health among school children.

PURPOSE

This study aimed to determine the effects of hand grip muscle strength (HGS), vitamin D in addition to diets, and PA on bone health status among 6-12 years old schoolchildren.

METHODS

This study was based on a cross-sectional observational design, which was descriptive in nature. A diverse sample of 560 elementary school children aged 6-12 years old were invited to participate in this descriptive cross-sectional study. The Dual-Energy X-Ray Absorptiometry (DXA), QUS technique, and ACTi graph GT1M accelerometer were used respectively as a valid tools to identify BMD, BMC, and other parameters of bone health like c-BUA values and bone stiffness (SI), and physical activity (PA) of all individuals participated in this study. In addition, a hydraulic dynamometer was used to measure hand grip strength among the participants. Moreover, an immunoassay technique was used to measure the serum levels of vitamin 25(OH)D level, and bone metabolism markers; NTX, DPD, Ca, and sBAP in all participants. Bone loss (osteoporosis) was cross-sectionally predicted in 19.64% of the total population, most of whom were girls (14.3% vs. 5.4% for boys; P = 0.01). Compared to boys, the incidence of osteoporosis was higher and significantly correlated in girls with lower HGS, deficient vitamin D, inadequate vitamin D and Ca intake, greater adiposity, poor PA, and lower sun exposure. Also, in girls, lower vitamin 25(OH)D levels, and poor HGS were shown to be significantly associated with lower values of BMD, BMC, SI, and higher values of bone resorption markers; NTX, DPD, and sBAP and lower serum Ca than do in boys. The findings suggested that deficient vitamin D, lower HGS, adiposity, PA, and sun exposure as related risk factors to the pravelence of bone loss among school children, particularly in girls. In addition, these parameters might be considered diagnostic non-invasive predictors of bone health for clinical use in epidemiological contexts; however, more studies are required.

Analysis of the association between osteoporosis and muscle strength in Korean adults: a national cross-sectional study

BACKGROUND

This study aimed to examine the associations between osteoporosis and hand grip strength (HGS), a surrogate marker of muscular strength, among Korean adults stratified by body mass index (BMI), age, and renal function.

METHODS

This study was conducted using the data obtained from the Korea National Health and Nutrition Examination Survey 2015-2019, a cross-sectional and nationally representative survey performed by the Korea Centers for Diseases Control and Prevention.

RESULTS

Of the 26,855 subjects included in this study, those with low muscle strength (LMS) and normal muscle strength were showed in 4,135 (15.4%) and 22,720 (84.6%) subjects, respectively. The osteoporotic subjects had a higher prevalence rate for LMS than those without osteoporosis after adjusting for age [odds ratio (OR), 1.684; 95% confidence interval (CI), 1.500-1.890). The subjects with osteoporosis and BMI < 18.5 kg/m2 also had a higher prevalence rate for LMS after adjusting for age compared to those with non-osteoporosis and BMI < 18.5 kg/m2 (OR, 1.872; 95% CI, 1.043-3.359). Compared to the non-osteoporotic subjects with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2, those with osteoporosis and eGFR ≥ 60 mL/min/1.73 m2 had a higher prevalence rate for LMS after controlling for age and sex (OR, 1.630; 95% CI, 1.427-1.862).

CONCLUSIONS

The results showed that osteoporosis was likely to contribute to an increased prevalence rate of LMS in terms of HGS. Aging, BMI, and renal function also had significant effects on the association between osteoporosis and LMS. This association is likely to assist in developing better strategies to estimate bone health in clinical or public health practice.

Effects of elastase-induced emphysema on muscle and bone in mice

Chronic obstructive pulmonary disease (COPD) causes sarcopenia and osteoporosis. However, the mechanisms underlying muscle and bone loss as well as the interactions between muscle and bone in the COPD state remain unclear. Therefore, we herein investigated the effects of the COPD state on muscle and bone in mice intratracheally administered porcine pancreatic elastase (PPE). The intratracheal administration of PPE to mice significantly reduced trabecular bone mineral density (BMD), trabecular bone volume, trabecular number, cortical BMD and cortical area. It also significantly decreased grip strength, but did not affect muscle mass or the expression of myogenic differentiation-, protein degradation- or autophagy-related genes in the soleus and gastrocnemius muscles. Among the myokines examined, myostatin mRNA levels in the soleus muscles were significantly elevated in mice treated with PPE, and negatively related to grip strength, but not bone parameters, in mice treated with or without 2 U PPE in simple regression analyses. Grip strength positively related to bone parameters in mice treated with or without PPE. In conclusion, we showed that a PPE model of COPD in mice exerts dominant effects on bone rather than skeletal muscles. Increased myostatin expression in the soleus muscles of mice in the COPD state may negatively relate to a reduction in grip strength, but not bone loss.

Influence of Muscle Mass and Strength on Bone Mineralisation with Consideration of Sclerostin Concentration

Osteoporosis is a disease characterised by a reduction in bone strength due to increased porosity and impaired mineralisation. In our study, we investigated whether muscle strength and mass exert a significant effect on bone mineral density in young adult women. We also tested whether sclerostin can be used as an indicator in the assessment of bone mineralisation. The study included 111 patients. All patients had their bone mineral density determined in the L1-L4 section of the lumbar spine and in the whole skeleton. The parameters of fat mass (FM), lean body mass (LBM) and visceral fat mass (VF) were also determined. Metabolic activity of osteocytes was assessed by measuring the serum sclerostin concentration. There was a statistically significant association of both hands' muscle strength with all parameters expressing bone mineralisation. A statistically significant relationship was also obtained between BMD L1-L4 and the body mass components (FM, LBM). Sclerostin levels in the study did not differ between groups with normal and reduced bone mineral density. Muscle strength assessment may be a potential exponent of reduced bone mineral density, also used clinically in young adult women. The utility of sclerostin in the clinical assessment of bone mineralisation has not been demonstrated.

Effects of obesity with reduced 25(OH)D levels on bone health in elderly Chinese people: a nationwide cross-sectional study

Background

Obesity is often accompanied by lower 25(OH)D levels, whereas these two parameters exhibit opposite effects on bone health. It is uncertain what are the effects of lower 25(OH)D levels in obesity on bone health in elderly Chinese people.

Methods

A nationally representative cross-sectional analysis of China Community-based Cohort of Osteoporosis (CCCO) was performed from 2016 to 2021, which consisted of 22,081 participants. Demographic data, disease history, Body mass index (BMI), bone mineral density (BMD), the levels of the biomarkers of vitamin D status and those of bone metabolism markers were measured for all participants (N = 22,081). The genes (rs12785878, rs10741657, rs4588, rs7041, rs2282679 and rs6013897) related to 25(OH)D transportation and metabolism were performed in a selected subgroup (N = 6008).

Results

Obese subjects exhibited lower 25(OH)D levels (p < 0.05) and higher BMD (p < 0.001) compared with those of normal subjects following adjustment. The genotypes and allele frequency of rs12785878, rs10741657, rs6013897, rs2282679, rs4588 and rs7041 indicated no significant differences among three BMI groups following correction by the Bonferroni's method (p > 0.05). The levels of total 25(OH)D (ToVD) were significantly different among the GC1F, GC1S and GC2 haplotype groups (p < 0.05). Correlation analysis indicated that ToVD levels were significantly correlated with parathyroid hormone levels, BMD, risk of osteoporosis (OP) and the concentration levels of other bone metabolism markers (p < 0.05). Generalized varying coefficient models demonstrated that the increasing BMI, ToVD levels and their interactions were positively associated with BMD outcomes (p < 0.001), whereas the reduced levels of ToVD and BMI increased the risk of OP, which was noted notably for the subjects with reduced ToVD levels (less than 20.69 ng/ml) combined with decreased BMI (less than 24.05 kg/m²).

Conclusion

There was a non-linear interaction of BMI and 25(OH)D. And higher BMI accompanied by decreased 25(OH)D levels is associated with increased BMD and decreased incidence of OP, optimal ranges exist for BMI and 25(OH)D levels. The cutoff value of BMI at approximately 24.05 kg/m² combined with an approximate value of 25(OH)D at 20.69 ng/ml are beneficial for Chinese elderly subjects.

The relationship between sarcopenia-related measurements and osteoporosis: The SARCOP study

As muscle and bone are closely-related, we have explored the association between sarcopenia-related measurements and bone mineral density (BMD) (and osteoporosis) in postmenopausal women. Grip strength, anterior thigh muscle thickness and chair stand test were found to be related with BMD. Additionally, grip strength < 22 kg increased the odds ratio of osteoporosis 1.6 times.

INTRODUCTION

As muscle and bone are two closely related tissues, we aimed to investigate the association between sarcopenia-related measurements (i.e., sonographic anterior thigh muscle thickness, grip strength, chair stand test (CST), gait speed) and clinical factors, lumbar/femoral BMD, and the presence of osteoporosis (OP) in postmenopausal women.

METHODS

Community dwelling postmenopausal women from two physical and rehabilitation medicine outpatient clinics were consecutively included in this cross-sectional study. Demographic data, age, weight, height, education/exercise status, smoking, and comorbidities were registered. BMD measurements were performed from lumbar vertebrae (L1-4) and femoral neck using dual energy X-ray absorptiometry (DXA). A T-score of ≤ -2.5 SD in the lumbar vertebrae (L1-L4) and/or femoral neck was accepted as OP. Anterior thigh muscle thickness (MT) at the midthigh level was measured sonographically using a linear probe. Grip strength was measured from the dominant side. Physical performance was assessed by CST and gait speed.

RESULTS

Among 546 postmenopausal women, 222 (40.7%) had OP. Among sarcopenia-related parameters, grip strength and anterior thigh MT were positively associated with lumbar vertebral BMD. CST performance was positively associated with femoral neck BMD. After adjusting for confounding factors, low grip strength (< 22 kg) increased 1.6 times the risk of OP.

CONCLUSION

Loss of muscle mass/function (i.e., sarcopenia) can coexist with loss of trabecular and cortical bone. To this end, grip strength and anterior thigh MT seem to be associated with the lumbar vertebral BMD, while CST is associated with the femoral neck BMD. Lastly, low grip strength might have an association with postmenopausal OP.

Causal associations of hand grip strength with bone mineral density and fracture risk: A mendelian randomization study

BACKGROUND

Muscle strength has been shown to exert positive effects on bone health. The causal relationship between hand grip strength and osteoporosis is an important public health issue but is not fully revealed. The goal of this study was to investigate whether and to what extent hand grip strength affects bone mineral density (BMD) and fracture risk.

METHODS

We conducted a state-of-the-art two-sample Mendelian randomization analysis. Genomewide significant (P<5×10-8) single nucleotide polymorphisms associated with hand grip strength were obtained. Summary level data of BMD and fractures at different body sites (lumbar spine, heel, forearm and femoral neck) was obtained from a large-scale osteoporosis database. The inverse variance weighted method was the primary method used for analysis, and the weighted-median, MR-Egger were utilized for sensitivity analyses.

RESULTS

The results provided strong evidence that hand grip strength trait was causally and positively associated with lumbar spine BMD (β: 0.288, 95% CI: 0.079 to 0.497; P=0.007), while no causal relationship was found between hand grip strength and BMD at heel (β: -0.081, 95% CI: -0.232 to 0.070; P=0.295), forearm (β: 0.-0.101, 95% CI: -0.451 to 0.248; P=0.571) or femoral neck (β: 0.054, 95% CI: -0.171 to 0.278; P=0.639). In addition, no statistically significant effects were observed for hand grip strength on fracture risks (β: -0.004, 95% CI: -0.019 to 0.012; P=0.662).

CONCLUSIONS

This study showed a positive causal relationship between hand grip strength and lumbar BMD, which is the most common site of osteoporotic fracture, but did not find a causal relationship between hand grip strength and BMD of heel, forearm, or femoral neck. No statistically significant effect of hand grip strength on fracture risk was observed. This study indicates variations in the abilities of hand grip strength trait to causally influence BMD at different skeleton sites. These results should be considered in further studies and public health measures on osteoporosis prevention strategies.

Bone Strength of the Calcaneus Is Associated with Dietary Calcium Intake in Older Japanese Men, but Not Women

The relationship between calcium intake and bone strength in older Asian individuals, including Japanese, is controversial; therefore, we herein investigated this relationship in older Japanese populations. We performed a cross-sectional analysis of 314 participants older than 65 years who voluntarily participated in a medical examination and responded to questionnaires. The osteo-sono assessment index (OSI) measured at the right calcaneus using a quantitative ultrasonic device was used as an indicator of bone strength. The daily dietary intake of calcium was assessed using a brief-type self-administered diet history questionnaire. A two-way analysis of covariance revealed a significant interaction between sex and calcium intake on the OSI (p < 0.01). A multiple regression analysis showed a positive correlation between calcium intake and the OSI in males (p < 0.01), but not females (p = 0.27). In females, grip strength divided by body weight positively correlated with the OSI (p = 0.04). The present results suggest that a higher calcium intake contributes to bone strength in older Japanese males. Although a higher grip strength may contribute to bone strength in females, the potential of estrogen as a confounding factor needs to be considered.

Association of Knee Extensor Muscle Strength and Cardiorespiratory Fitness With Bone Stiffness in Japanese Adults: A Cross-sectional Study

BACKGROUND

Knee extensor muscle strength and cardiorespiratory fitness (CRF) are major components of physical fitness. Because the interactive association of knee extensor muscle strength and CRF with bone health remains unclear, we aimed to investigate such association in Japanese adults.

METHODS

Altogether, 8,829 Japanese adults (3,731 men and 5,098 women) aged ≥45 years completed the maximum voluntary knee extension test, submaximal exercise test, medical examination, and a questionnaire on lifestyle habits. Using an osteo-sono assessment index, low bone stiffness tendency was defined as 80% under the young-adults mean. Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) were calculated after confounder adjustment.

RESULTS

Overall, 542 men (14.5%) and 978 women (19.2%) had low bone stiffness tendency. We observed an inverse association between muscle strength and low bone stiffness tendency after adjustment for CRF in both sexes (P for linear trend <0.001). Compared with the lowest CRF, the multivariable ORs for low bone stiffness tendency in the highest CRF were 0.47 (95% CI, 0.36-0.62) for men and 1.05 (95% CI, 0.82-1.35) for post-menopausal women (P < 0.001 and P = 0.704, respectively). No interactive association between muscle strength and CRF for low bone stiffness tendency existed in both sexes and irrespective of menopausal status.

CONCLUSION

Knee extensor muscle strength and CRF were associated additively, not synergistically, with bone health. Maintaining high levels of both physical fitness components may improve musculoskeletal health in the cohort. The relationship between physical fitness and bone status should be longitudinally investigated in the future.

Utilizing nomograms to predict prevalent vertebral fracture risk: An analysis of dysmobility syndrome in a community-dwelling population

BACKGROUND

To determine a reliable method to predict prevalent vertebral fractures (VF) by assessing the association between dysmobility syndrome (DS) and VF in a community-dwelling population.

METHODS

This cross-sectional study enrolled 518 participants from fracture-prevention educational activities held in multiple communities in Taiwan. Assessments included questionnaires, fracture risk assessment tool (FRAX), bone mineral density (BMD) and body composition using dual-energy x-ray absorptiometry (DXA), lateral thoracolumbar spine x-rays (specifically T8-S1), grip strength (GS), walking speed, and fall history.

RESULTS

DS was noted in 257 participants (49.6%) and VF was identified in 196 participants (37.8%). A higher prevalence of VF was noted in those with DS. The prevalence of VF was significantly associated with age, gender, FRAX both with and without BMD, osteoporosis, low GS, and DS. In multivariate models accounting for age and sex, the c-index was greater in those with low GS plus osteoporosis as compared to DS alone. Low GS, osteoporosis, and pre-BMD FRAX all had similar c-indexes. Pre-BMD FRAX plus low GS and osteoporosis was superior in predicting VF compared to pre-BMD FRAX plus low GS or osteoporosis alone. Besides the inclusion of age and gender, the nomogram with pre-BMD FRAX major osteoporosis fracture probability (MOF) plus low GS had improved correlation between the estimated and actual VF probability than those with pre-BMD FRAX MOF plus osteoporosis.

CONCLUSIONS

The constructed nomogram containing pre-BMD FRAX MOF plus low GS may be considered as a first-line prevalent VF screening method. Those with high-risk scores should subsequently undergo vertebral radiography and/or BMD.

Correlation of muscle mass and bone mineral density in the NHANES US general population, 2017-2018

The appendicular skeletal muscle mass index (ASMI) is commonly used to evaluate human skeletal muscle mass. Muscle, an adjacent tissue of bone, is closely related to bone growth and development. The purpose of this study was to explore the association between the ASMI and lumbar bone mineral density (BMD) to identify potential risk factors for osteoporosis. We analyzed the data collected by the NHANES from 2017 to 2018, and finally included 948 participants aged 40 to 59 years. We evaluated the correlation between the ASMI and lumbar spine BMD using univariate and multiple linear regression models. The ASMI was calculated from height and appendicular skeletal muscle mass obtained by dual energy X-ray absorptiometry. Lumbar spine BMD was obtained by dual energy X-ray absorptiometry and used as an observation in our study. In all the models, ASMI was significantly associated with lumbar spine BMD (model 1: β = 0.013, P < .001; model 2: β = 0.013, P < .001). In the subgroup analysis stratified by sex, this positive correlation was present in both sexes (male: β = 0.023, P < .001, β = 0.022, < 0.001; female: β = 0.030, P < .001, β = 0.031, P < .001). This study showed that the ASMI was positively associated with lumbar BMD, and that this correlation is present in both men and women.

A bi-directional Mendelian randomization study of the sarcopenia-related traits and osteoporosis

Both sarcopenia and osteoporosis are common geriatric diseases causing huge socioeconomic burdens, and clinically, they often occur simultaneously. Observational studies have found a controversial correlation between sarcopenia and osteoporosis and their causal relationship is not clear. Therefore, we performed a bi-directional two-sample Mendelian randomization (MR) analysis to assess the potential causal relationship between sarcopenia-related traits (hand grip strength, lean mass, walking pace) and osteoporosis. Our analysis was performed by applying genetic variants obtained from the UK Biobank and the GEnetic Factors for OSteoporosis (GEFOS) datasets. We used inverse-variance weighted (IVW) and several sensitivity analyses to estimate and cross-validate the potential causal relationship in this study. We found that bone mineral density (BMD) was causally positively associated with left-hand grip strength (β = 0.017, p-value = 0.001), fat-free mass (FFM; right leg FFM, β = 0.014, p-value = 0.003; left arm FFM, β = 0.014, p-value = 0.005), but not walking pace. Higher hand grip strength was potentially causally associated with increased LS-BMD (right-hand grip strength, β = 0.318, p-value = 0.001; left-hand grip strength, β = 0.358, p-value = 3.97 × 10-4). In conclusion, osteoporosis may be a risk factor for sarcopenia-related traits and muscle strength may have a site-specific effect on BMD.

Daily activity relates to not only femoral bone mineral density, but also hip structural analysis parameters: A cross-sectional observational study

Objectives

Physical activity to maintain bone mass and strength is important for hip fracture prevention. We aim to investigate the relationship between physical performance/activity status and bone mineral density (BMD)/hip structural analysis (HSA) parameters among postmenopausal women in Japan.

Methods

Sixty-two postmenopausal women diagnosed with osteoporosis (mean age: 72.61 ± 7.43 years) were enrolled in this cross-sectional observational study. They were evaluated for BMD and HSA in the proximal femur by dual-energy X-ray absorptiometry and underwent several physical performance tests, the Geriatric Locomotive Function Scale of 25 questions (GLFS-25). Principal component analysis (PCA) was used to summarize data on the BMD/HSA parameters. Partial correlation analysis, multiple regression analysis, and structural equation modeling (SEM) were performed to investigate the relationship between physical performance/activity status and BMD/HSA parameters of the proximal femur.

Results

In a partial correlation analysis adjusted for age and body mass index (BMI), GLFS-25 scores were correlated with HSA parameter (|r| = 0.260–0.396, P < 0.05). Principal component 1 (PC1) calculated by PCA was interpreted as more reflective of bone strength based on the value of BMD/HSA parameters. The SEM results showed that the model created by the 3 questions (Q13, brisk walking; Q15, keep walking without rest; Q20, load-bearing tasks and housework) of the GLFS-25 had the best fit and was associated with the PC1 score (β = −0.444, P = 0.001).

Conclusions

The GLFS-25 score was associated with the BMD/HSA parameter, which may reflect the bone strength of the proximal femur as calculated by PCA.

Relationship Between Muscle Strength, Body Composition and Bone Mineral Density in Adolescents

Adolescence is an important period for the acquisition of bone mass, which can be enhanced by several factors. This study aimed examine the relationships of handgrip strength, free-fat mass, and fat mass with bone mineral density in adolescents. 118 adolescents (60 girls), aged 10 to 14 years, participated in the study. Information on sex, age, handgrip strength, free-fat mass, fat mass and bone mineral density were collected. Multiple linear regression analyses were conducted to examine possible relationships between bone mineral density and handgrip strength, free-fat mass and fat mass. There was a relation between handgrip strength and free-fat mass with bone mineral density in both sexes. Fat mass was correlated with bone mineral density only in girls (r= 0.314, p< 0.014). The final models, adjusted for sexual maturation, included free-fat mass (girls - β= 0.419, p< 0.001; boys - β= 0.455; p< 0.001) and handgrip strength (girls - β= 0.358, p< 0.05; boys - β= 0.325; p< 0.05) and these variables together explained 51.8% and 62.9% of the variation of bone mineral density, in girls and boys, respectively. Handgrip strength and free-fat mass were positively associated with bone mineral density. A sex-specific difference indicated that higher levels of free-fat mass are of paramount importance for both sexes.

Combined results of three physical performance tests predict incident fracture independently of aBMD in community-dwelling elderly Japanese men: Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Cohort Study

BACKGROUND

Several studies have examined the association between physical performance and fracture in women, but few such studies have targeted elderly men. This study aimed to determine whether the combined results of several physical performance tests can predict the subsequent incidence of fractures in elderly men after adjusting for confounding factors.

METHODS

Of the 2174 elderly men who participated in this study, 2012 completed the baseline study visit, including physical performance tests (walking speed, hand grip strength, and one-leg standing) and measurement of bone mineral density by dual-energy X-ray absorptiometry. Follow-up study visits were conducted five and ten years later, during which incident fractures were identified by detailed interviews. We excluded 140 men with diseases or who took medications known to affect bone metabolism at baseline, 185 with missing values for predictors and potential confounding factors, and one who did not participate in any of the follow-up study visits. The remaining 1686 men were analyzed. Each physical performance test was analyzed by quartiles. Poor performance was defined as belonging to the worst quartile of performance. The association between physical performance and fracture was assessed using Cox proportional hazards models.

RESULTS

We identified 175 clinical fractures (osteoporotic fracture: 77, major osteoporotic fracture: 48) in 1686 men during a mean follow-up period of 8.4 years. After adjusting for potential confounding factors including bone mineral density, men who performed poorly on all three physical performance tests had a 3.7-fold higher risk of osteoporotic fracture and a 6.6-fold higher risk of major osteoporotic fracture than men who did not perform poorly on any of the tests.

CONCLUSIONS

Japanese elderly men who performed poorly on all three physical performance tests had a significantly higher risk of incident osteoporotic fracture independently of bone mineral density. The combined results of several physical performance tests may be useful for predicting incident fractures in elderly men.

Handgrip strength, dynapenia, and related factors in postmenopausal women

OBJECTIVE

This study aimed to evaluate the prevalence of dynapenia and factors related to low dominant handgrip strength (HGS) in postmenopausal women.

METHODS

A cross-sectional study was performed on 249 postmenopausal women aged 50 to 84 years. The following variables were recorded: age, age at menopause, smoking status, and the HGS measured with a digital dynamometer, body mass index, and adiposity assessed by bioelectric impedance. The physical activity level was evaluated by using the International Physical Activity Questionnaire. Bone mineral density was reported as T-scores, and blood biochemical parameters (calcium, phosphorus, vitamin D, and parathormone levels) were measured.

RESULTS

31.3% of women had dynapenia, and those aged ≥65 years had lower HGS (P < 0.001). Age at menopause was also associated with HGS, with those with menopause < 51 showing lower HGS (P = 0.005). Likewise, fat content ≥ 40%, and osteopenia/osteoporosis were also related to lower strength (P < 0.001). There was no statistically significant difference among HGS with respect to body mass index, smoking status, and plasma levels of vitamin D. A logistic regression model with lower Akaine Information Criterion showed that for every year in age and for each 1% of adiposity, women were more likely to have dynapenia with odd ratio (OR): 1.09; 95% and confidence interval (CI): 1.04 to 1.14 and OR: 1.06; 95% CI: 1.00 to 1.13, respectively. Conversely, women with higher femoral neck T-score were less likely to have dynapenia (OR: 0.53; 95% CI: 0.35-0.78).

CONCLUSIONS

HGS was associated with age at menopause, bone mineral density, and adiposity adjusted by age. The age and adiposity were significantly associated with a higher risk of dynapenia, whereas women with higher femoral neck T-score were less likely to have dynapenia.

The Association Between Walking Speed and Bone Turnover Markers in Older Adults

Background  Previous research conducted among institutionalized older adults has reported increased bone turnover markers (BTMs) in those subjects with mobility limitation. However, the association between walking speed and bone metabolism has not been well described in community-dwelling older adults. Methods The National Health and Nutrition Examination Survey 1999-2000 and 2001-2002 cycles were used to determine the association between the 20-feet walking speed test and bone alkaline phosphatase (BAP) and the cross-linked N-telopeptides of type I bone collagen (NTx). Sex-specific general linear models adjusted for potential confounders were assembled to examine the independent association between the time to complete the walking speed test grouped into quartiles and the logarithmic transformations of BAP and NTx levels.  Results Of 2,521 older adults, 25.8% were defined as having mobility limitation. In both genders, BTM levels progressively increased as the time to complete the walking test also increase. Indeed, women and men who completed the walking speed test in the worst time quartile had on average 6% and 2.8% higher NTx levels than their counterparts who completed the test in the best time quartile, respectively. Likewise, BAP levels also progressively increased across walking speed time quartiles, but to a lesser degree. Notably, NTx levels were 4.7% and 2.6% higher in women and men with mobility limitation than those without, respectively. In contrast, BAP levels did not significantly differ in older adults regardless of their mobility limitation status. Conclusions Community-dwelling older adults with slower walking speeds and mobility limitation consistently had evidence of increased bone resorption. Thus, the present findings indicate that older adults with mobility limitation should be considered at risk of osteoporosis.

Grip strength performance from 9431 participants of the GenoFit study: normative data and associated factors

Weak grip strength is a strong predictor of multiple adverse health outcomes and an integral diagnostic component of sarcopenia. However, the limited availability of normative data for certain populations impedes the interpretation of grip performance across adulthood. This study aimed to establish normative data and low grip strength thresholds in a large adult population, and to examine associations between grip strength and clinically relevant health variables. A total of 9431 adults aged between 18 and 92 years participated in this study (mean age: 44.8 ± 13.4 years; 57% females). Grip strength, body composition, and cardiorespiratory (CR) fitness were assessed using hand dynamometry, dual-energy x-ray absorptiometry and physical work capacity tests, respectively. Low grip strength was established according to criteria of the European Working Group on Sarcopenia in Older People. Normative data and t-scores, stratified by sex and age groups, are presented. Grip performance was associated with lean mass, skeletal muscle index (SMI), fat mass, CR fitness, bone mineral density (BMD), android/gynoid ratio, disease prevalence and physical activity levels (all p < 0.001) after controlling for multiple potential confounders. Individuals with weak grip strength had lower lean mass, SMI, CR fitness (all p < 0.001) and BMD (p = 0.001), and higher disease prevalence (p < 0.001), compared to healthy controls, although sex-specific differences were observed. Grip strength has practical screening utility across a range of health domains. The normative data and grip strength thresholds established in this study can guide the clinical interpretation of grip performance and facilitate timely therapeutic strategies targeting sarcopenia.

The relationship between serum folate and grip strength in American adults

We used data from NHANES to explore the associations between serum folate and grip strength, and found that high levels of serum folate were associated with increased grip strength among females rather than males. It is recommended to maintain a proper level of serum folate, especially in women.

PURPOSE

Associations and dose-response relationships between serum total folate, 5-methyltetrahydrofolate, and grip strength in general adults were unknown. Thus, we conducted this analysis for further exploration.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) database of 2011-2014 cycle were used. The independent variables including serum total folate, combined total folate (total folate plus Mefox), and 5-methyltetrahydrofolate. The dependent variable was BMI-corrected grip strength. Linear regression and the restricted cubic splines were used in our analyses.

RESULTS

A total of 9079 adults aged over 20 years were included. In multivariate-adjusted model 2, compared with quartile (Q) 1, grip strength increased in Q3 of combined total folate and total folate, and the weighted β values with 95% confidence intervals (CIs) of grip strength were 0.06 (0.01, 0.12) and 0.06 (0.00, 0.10) for combined total folate and total folate, respectively. In the stratified analysis by gender, positive relationships between combined total folate, total folate, and 5-methyltetrahydrofolate and grip strength were found only in females, with β (95% CIs) of 0.07 (0.02, 0.12), 0.07 (0.03, 0.12), and 0.09 (0.05, 0.13) for combined total folate, total folate, and 5-methyltetrahydrofolate in Q4, respectively. Non-linear positive dose-response relationships between serum folate and grip strength were also found only in females, not in males.

CONCLUSION

Our study suggested a positive association between serum folate and grip strength, while this positive association was only found in females; besides, the dose-response relationships were in a non-linear trend. Thus, it is recommended to maintain a proper serum folate level to keep better muscle strength, especially for women.

Effects of the association between APOE rs405509 polymorphisms and gene-environment interactions on hand grip strength among middle-aged and elderly people in a rural population in southern China

Background

Hand grip strength is a complex phenotype. The current study aimed to identify the effects of the association between APOE rs405509 polymorphisms and gene-environment interactions on hand grip strength among middle-aged and elderly people in a rural population in Gongcheng, southern China.

Methods

APOE rs405509 polymorphisms in 1724 participants (695 men and 1029 women, aged 45–97 years old) were genotyped using the Sequenom MassARRAY platform. Statistical analysis was conducted using SPSS 21.0 and Plink 1.90.

Results

The APOE rs405509 G allele was associated with lower hand grip strength in all participants (β = −1.04, P value <0.001), and the correlation seemed to be even stronger among women. A significant gene-environment interaction was observed between APOE rs405509 and smoking, especially in men. The hand grip strength of male smokers carrying the GG genotype was significantly higher than that of nonsmokers (P value = 0.004).

Conclusions

APOE rs405509 polymorphisms might be genetic factors that affect hand grip strength in a rural population in Gongcheng, southern China. The APOE rs405509-smoking interaction has an impact on hand grip strength.

Osteoporosis and fractures in rheumatoid arthritis

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is associated with increased risk for osteoporotic fracture. We highlight RA-specific risk factors for bone mineral density (BMD) loss and fractures and considerations regarding the diagnosis and treatment of osteoporosis in patients with RA.

RECENT FINDINGS

Anticitrullinated protein antibody (ACPA) positivity, although associated with low BMD in early RA, is not associated with accelerated BMD loss over time when compared to ACPA negative individuals. Studies have found reduced BMD in individuals on low doses of glucocorticoids (GCs). Poor functional status and frailty are additional important risk factors for low BMD and fractures. Heightened fracture risk in RA may be mitigated by tight disease control, and biologic therapies are associated with more stable BMD compared to nonbiologic therapies. Evidence-based guidelines specific for treating osteoporosis in patients with RA do not exist. Thus, treatment decisions are based on general osteoporosis guidelines, taking into account additional RA-specific risk factors.

SUMMARY

Recent studies have advanced knowledge of RA-specific risk factors for BMD loss and fractures. Future studies applying these findings to modify established fracture risk algorithms as well as evaluating osteoporosis treatments in RA cohorts are needed to reduce the risk of disabling fractures in these patients.

Intensity Matters for Musculoskeletal Health: A Cross-Sectional Study on Movement Behaviors of Older Adults from High-Income Scottish and Low-Income South African Communities

This study aimed to investigate differences in physical activity (PA) patterns and the associations between objectively measured 24-h movement behaviors and musculoskeletal measures (muscle strength, muscle mass, physical performance, and bone mineral density) in a high-income and a low-income community. This cross-sectional study recruited independent living older adults aged 60-85 years from high-income Scottish (n = 150) and low-income South African (n = 138) settings. Participants completed demographic and health questionnaires, and testing included body composition and bone mineral density (dual energy X-ray absorptiometry), physical performance (grip strength, gait speed), and PA (accelerometry). Participants accumulated similar amounts of weekly total PA, however, the Scottish cohort engaged in more moderate-to-vigorous intensity PA (MVPA) and sedentary behavior (SB), while the South African cohort spent more time sleeping and in light intensity PA (LPA). From compositional data analysis, more time spent in MVPA relative to the other movement behaviors was positively associated with higher muscle mass (p < 0.001) and strength (p = 0.001) in the Scottish cohort. Conversely, more time spent in MVPA was associated with faster gait speed (p < 0.001) and greater hip bone mineral density (p = 0.011) in the South African cohort. Our findings confirm the beneficial role of MVPA in both high- and low-income cohorts, however, the relationship MVPA had with components of musculoskeletal health in older adults differed between settings.

Low Grip Strength and Muscle Mass Increase the Prevalence of Osteopenia and Osteoporosis in Elderly Women

The risk of developing low muscle strength and muscle mass is affected by aging, osteopenia, and osteoporosis and increases with age. The purpose of this study was to investigate the prevalence and cutoff values for osteoporosis and osteopenia according to the level of grip strength and muscle mass associated with sarcopenia. A cross-sectional study was conducted, and data from 734 women aged from 60 to 79 years old who visited the healthcare center from 2016 to 2019 were analyzed. Bone mineral density was measured on the lumbar spine from 1-4 using dual X-ray absorptiometry. Osteopenia and osteoporosis were classified on the basis of a T-score ranging from -1.0 to -2.4 and under -2.5, respectively. The diagnostic criteria for sarcopenia were a grip strength of <18 kg and muscle mass of <5.7 kg/m² according to the Asian Working Group of Sarcopenia. Logistic regression analysis was used to determine the odds ratio, and the receiver operating characteristic curve was applied for the cutoff values. There were 351 (47.8%) patients with osteopenia and 152 (20.7%) patients with osteoporosis. The prevalence of osteopenia increased 1.593 times in the lowest grip strength group and 1.810 times in the lowest muscle mass group (p < 0.05). For osteoporosis, the lowest grip strength increased 2.512 times and the lowest muscle mass increased 2.875 times, compared to the highest grip strength group. In the sarcopenia group, osteopenia increased 2.451 times and osteoporosis increased 3.137 times, compared to the non-sarcopenia group (p < 0.05). In conclusion, the prevalence of osteoporosis and osteopenia was increased in elderly women with low grip strength and muscle mass.

Impact of Pulse Wave Velocity and Parameters Reflecting Android Type Fat Distribution on Left Ventricular Diastolic Dysfunction in Patients with Chronic Coronary Syndromes

Background: Left ventricular diastolic dysfunction (LVDD) is caused by a decreased left ventricle relaxation and is associated with an increased risk of symptomatic heart failure (HF) and excessive mortality. Aim: To evaluate the frequency and factors related to LVDD in the population with chronic coronary syndromes (CCS). Methods: 200 patients (mean age 63.18 ± 8.12 years, 75.5% male) with CCS were included. LVDD was diagnosed based on the recent echocardiography guidelines. Results: LVDD was diagnosed in 38.5% of CCS population. From the studied factors, after adjustment for age, sex, and N-terminal pro-brain natriuretic peptide (NT-proBNP), LVDD associated positively with android/gynoid (A/G) fat mass ratio, left ventricular mass index (LVMI), and negatively with Z-score and left ventricular ejection fraction (LVEF). In stepwise backward logistic regression analysis, the strongest factors associated with LVDD were pulse wave velocity value, handgrip strength and waist to hip ratio (WHR). Conclusions: LVDD is common among CCS patients and it is associated with parameters reflecting android type fat distribution regardless of NT-proBNP and high-sensitivity troponin T concentrations. Deterioration in diastolic dysfunction is linked with increased aortic stiffness independently of age and sex. Further studies evaluating the effects of increasing physical fitness and lowering abdominal fat accumulations on LVDD in CCS patients should be considered.

Bone-Muscle Mutual Interactions

PURPOSE OF REVIEW

The purpose of this review is to describe the current state of our thinking regarding bone-muscle interactions beyond the mechanical perspective.

RECENT FINDINGS

Recent and prior evidence has begun to dissect many of the molecular mechanisms that bone and muscle use to communicate with each other and to modify each other's function. Several signaling factors produced by muscle and bone have emerged as potential mediators of these biochemical/molecular interactions. These include muscle factors such as myostatin, Irisin, BAIBA, IL-6, and the IGF family and the bone factors FGF-23, Wnt1 and Wnt3a, PGE2, FGF9, RANKL, osteocalcin, and sclerostin. The identification of these signaling molecules and their underlying mechanisms offers the very real and exciting possibility that new pharmaceutical approaches can be developed that will permit the simultaneous treatments of diseases that often occur in combination, such as osteoporosis and sarcopenia.

Osteoporosis in Premenopausal Women: A Clinical Narrative Review by the ECTS and the IOF

CONTEXT

Consensus regarding diagnosis and management of osteoporosis in premenopausal women (PW) is still lacking due to few studies carried out in this population.

DESIGN

The European Calcified Tissue Society and the International Osteoporosis Foundation convened a working group to produce an updated review of literature published after 2017 on this topic.

RESULTS

Fragility fractures in PW are rare and mostly due to secondary osteoporosis (ie, in presence of an underlying disease such as hormonal, inflammatory, or digestive disorders). In absence of another disorder, low bone mineral density (BMD) together with fragility fractures qualifies as idiopathic osteoporosis. In contrast, low BMD alone does not necessarily represent osteoporosis in absence of bone microarchitectural abnormalities. BMD increases in PW with osteoporosis when the underlying disease is treated. For example, in celiac disease, an increase of 9% in radius trabecular volumetric density was achieved after 1 year of gluten-free diet, while anti-tumor necrosis factor alpha improved BMD in PW with inflammatory bowel diseases. In amenorrhea, including anorexia nervosa, appropriately delivered estrogen replacement therapy can also improve BMD. Alternatively, antiresorptive or anabolic therapy has been shown to improve BMD in a variety of conditions, the range of improvement (3%-16%) depending on skeletal site and the nature of the secondary cause. No studies were powered to demonstrate fracture reduction. The effects of bisphosphonates in childbearing women have been scantly studied and caution is needed.

CONCLUSION

The majority of PW with osteoporosis have an underlying disease. Specific therapy of these diseases, as well as antiresorptive and anabolic drugs, improve BMD, but without evidence of fracture reduction.

Measurement and Interpretation of Handgrip Strength for Research on Sarcopenia and Osteoporosis

Handgrip strength (HGS) is associated with several chronic diseases, cognitive decline, length of hospital-stay, and mortality. More importantly, HGS is one of the diagnostic criteria of sarcopenia and gaining attention because of its relevance to bone mineral density (BMD) and osteoporotic fractures. As the measurement of HGS is widely used in clinical practice as well as in research, its accurate measurement and interpretation are becoming more crucial. This review describes how to use different types of dynamometers accurately, the impact of body and arm positions and anthropometric parameters on HGS, the current reference values of HGS for sarcopenia research, and the updates on the relationship between HGS and BMD and osteoporotic fractures.

Vitamin D supplementation after the menopause

The purpose of this review was to assess recent evidence regarding the effects of low vitamin D levels on some highly prevalent clinical conditions of postmenopausal women. We reviewed and selected recent literature regarding menopause-related conditions associated with vitamin D deficiency and interventions to manage them. Low circulating 25-hydroxyvitamin D (25(OH)D) levels related to menopause are linked to diet, lifestyle, changes in body composition, insulin sensitivity, and reduced physical activity. Vitamin D supplementation increases serum 25(OH)D levels while normalizing parathyroid hormone and bone markers, and in women with serum 25(OH)D levels below 10 ng/ml supplementation may improve bone mineral density. Low vitamin D status has been associated with the metabolic syndrome, high triglyceride levels, and low high-density lipoprotein cholesterol levels. When compared with placebo, vitamin D supplementation may lower the risk of the metabolic syndrome, hypertriglyceridemia, and hyperglycemia. There is an inverse relationship between fat mass and serum 25(OH)D levels and, therefore, the dosage of supplementation should be adjusted according to the body mass index. Although vitamin D supplementation may improve glucose metabolism in prediabetic subjects, data regarding muscle strength are conflictive. There is evidence that vitamin D over-treatment, to reach extremely high circulating 25(OH)D levels, does not result in better clinical outcomes. The identification and treatment of vitamin D deficiency in postmenopausal women may improve their general health and health outcomes. Vitamin D supplementation should preferably be based on the use of either cholecalciferol or calcifediol.