The Relationship between Sarcopenia and Vitamin D Levels in Adults of Different Ethnicities: Findings from the West China Health and Aging Trend Study

Surveillance and Evaluation of Vitamin D Nutrition and Its Health Impact in Chinese Older Adults

Vitamin D is an essential fat-soluble vitamin for humans and vitamin D deficiency (VDD) affects all age groups, with older adults being at high risk of VDD. A deficiency in vitamin D has been associated with a range of health concerns in older adults, including osteomalacia and osteoporosis. Additionally, there is limited evidence suggesting that VDD may be associated with increased risk of developing cognitive impairment, muscle-wasting disorders, cardiovascular disease, type 2 diabetes mellitus, and mortality. This review synthesizes the latest research advances in China and abroad to provide detailed information on the current status of vitamin D nutritional monitoring, causes of deficiency, health risks, and proposed intake for reducing risk of diet-related noncommunicable diseases in the Chinese older adults.

Mesenchymal stem cell-specific Sirt1 overexpression prevents sarcopenia induced by 1,25-dihydroxyvitamin D deficiency

Sarcopenia, characterized by an age-related decline in skeletal muscle mass and function, is closely linked to vitamin D deficiency. This study examines the role of Sirtuin 1 (Sirt1) and its regulation by vitamin D in preventing sarcopenia. Utilizing wild-type, 1α-hydroxylase knockout (1α(OH)ase-/-), and Sirt1 transgenic (Sirt1Tg) 1α(OH)ase-/- mice, we investigated muscle Sirt1 levels, muscle mass, fiber type, and senescence markers. Our results demonstrated that 1,25-Dihydroxyvitamin D (1,25(OH)2D3) upregulated Sirt1 and myogenic factor MyoD1 expression in C2C12 myoblasts via VDR-mediated transcription. Sirt1 overexpression in mesenchymal stem cells (MSCs) significantly mitigated muscle mass reduction, improved fiber cross-sectional area, and increased type II fiber numbers in 1α(OH)ase-/- mice. Mechanistically, 1,25(OH)2D3 promoted muscle cell health by enhancing Sirt1 expression, which in turn reduced muscle cell senescence and the senescence-associated secretory phenotype (SASP) through decreased levels of acetylated nuclear p53 and p65, maintaining their cytoplasmic localization. Additionally, Sirt1 overexpression accelerated muscle regeneration post-injury by increasing embryonic myosin heavy chain expression and cell proliferation. These findings underscore the therapeutic potential of targeting vitamin D and Sirt1 pathways to prevent sarcopenia, suggesting that supplementation with active vitamin D and consequent Sirt1 activation could be effective strategies for managing age-related muscle wasting.

Age but not vitamin D is related to sarcopenia in vitamin D sufficient male elderly in rural China

This study aimed to identify the correlation of serum 25(OH)D level with sarcopenia and its components in Chinese elderly aged 65 years and above from rural areas. A total of 368 Chinese elderly aged 65 years and above in rural areas were enrolled. Indicators of muscle mass and strength, including the appendicular skeletal muscle mass (ASM), skeletal muscle index (SMI) and hand grip strength (HGS) were measured. Physical performance was assessed by the Short Physical Performance Battery (SPPB). Serum 25(OH)D levels were measured using the liquid chromatography with tandem mass spectrometry. Correlations of serum 25(OH)D level with sarcopenia and its components in Chinese elderly were identified by the binary logistic regression and linear regression analyses. The median serum 25(OH)D level was 34.80 ng/ml, and significantly higher in men than in women (40.70 ng/ml vs. 27.30 ng/ml). The prevalence of sarcopenia in our cohort was 21.5%, and higher in men than in women (29.4% vs. 10.8%). The serum 25(OH)D level was not correlated with sarcopenia, HGS and SPPB score in either male or female elderly. Positive correlations of age with sarcopenia, low HGS and low SPPB score were observed in male elderly, while significant correlations were not observed in females. Correlation analyses of sarcopenia components revealed that age was negatively correlated with SMI and gait speed in male elderly, but negatively correlated with the gait speed and positively correlated with the time to complete 5 sit-to-stand movements in female elderly. In conclusion, rural Chinese elderly have relatively high vitamin D level and prevalence of sarcopenia. Age but not serum 25(OH)D level is significantly correlated with sarcopenia in vitamin D sufficient male elderly.

Development and validation of a biological frailty score based on CRP, haemoglobin, albumin and vitamin D within an electronic health record database in France: a cross-sectional study

Objectives

To easily detect frailty in a timely fashion, enabling targeted interventions and appropriate monitoring, will be a major worldwide public health and economic challenge as the proportion of older people increases in the population. Based on a review and meta-analysis showing that C-reactive protein (CRP), haemoglobin, albumin and vitamin D are associated with frailty, we aimed to develop and validate a biological score using these biomarkers for the detection of frailty.

Design

We conducted a retrospective, cross-sectional, monocentric study using the electronic healthcare database of Lille University Hospital, France.

Participants

Inclusion criteria were patients aged 50 and over, being hospitalised at Lille University Hospital between 1 January 2008 and 31 December 2021. We identified patients whose CRP, haemoglobin, albumin and vitamin D levels were measured. We selected patients whose assays fell within normal thresholds, outside acute clinical situations.

Main outcome measures

To assess frailty, we used a scale adapted to electronic healthcare database, called the Hospital Frailty Risk Score. To develop and validate the predictive frailty score, the whole population was divided into a development and a validation cohort.

Results

26 554 patients were included, of which 17 702 were in the development cohort and 8852 in the validation cohort. Based on the results of the multivariate analysis, we developed an equation combining CRP, haemoglobin, albumin and vitamin D with age and sex to obtain a score referred to as the bFRAil (biological FRAilty) score. Within the validation cohort, the area under the curve for this score is 0.78 (0.77-0.80) and the negative predictive value is 83.7%.

Conclusions

This study has made it possible, for the first time, to develop and validate in a hospital setting a biological score called bFRAil score based on simple, easily measurable biomarkers for identifying frail patients in daily medical practice. Further studies are needed to validate its use.

Vitamin D and Sarcopenia in the Senior People: A Review of Mechanisms and Comprehensive Prevention and Treatment Strategies

This article reviews the mechanisms and prevention strategies associated with vitamin D and sarcopenia in older adults. As a geriatric syndrome, sarcopenia is defined by a notable decline in skeletal muscle mass and strength, which increases the risk of adverse health outcomes such as falls and fractures. Vitamin D, an essential fat-soluble vitamin, is pivotal in skeletal muscle health. It affects muscle function through various mechanisms, including regulating calcium and phosphorus metabolism, promoting muscle protein synthesis, and modulation of muscle cell proliferation and differentiation. A deficiency in vitamin D has been identified as a significant risk factor for the development of sarcopenia in older adults. Many studies have demonstrated that low serum vitamin D levels are significantly associated with an increased risk of sarcopenia. While there is inconsistency in the findings, most studies support the importance of vitamin D in maintaining skeletal muscle health. Vitamin D influences the onset and progression of sarcopenia through various pathways, including the promotion of muscle protein synthesis, the regulation of mitochondrial function, and the modulation of immune and inflammatory responses. Regarding the prevention and treatment of sarcopenia, a combination of nutritional, exercise, and pharmacological interventions is recommended. Further research should be conducted to elucidate the molecular mechanism of vitamin D in sarcopenia, to study genes related to sarcopenia, to perform large-scale clinical trials, to investigate special populations, and to examine the combined application of vitamin D with other nutrients or drugs. A comprehensive investigation of the interconnection between vitamin D and sarcopenia will furnish a novel scientific foundation and productive strategies for preventing and treating sarcopenia. This, in turn, will enhance the senior people's quality of life and health.

The relationship between low and asymmetric handgrip strength and low muscle mass: results of a cross-sectional study on health and aging trends in western China

OBJECTIVE

The aim was to determine the relationship between low handgrip strength (HGS) only, asymmetric HGS only, and low HGS combined with asymmetric HGS and low muscle mass in the West China Health and Aging Trends Study (WCHAT) data.

STUDY DESIGN

Individuals aged at least 50 years old were included in this cross-sectional study using WCHAT data. Demographic characteristics, such as age, marital status, education level, ethnicity, and drinking and smoking history, as well as chronic diseases, were recorded for all participants. The HGS of both hands was tested three times using a grip dynanometer with the participant in a standing position with arms extended, before recording the maximum value for both hands. The maximum value referred to values < 28 kg and < 18 kg for males and females, respectively. HGS ratios (non-dominant HGS/dominant HGS) of < 0.90 or > 1.10 suggest asymmetric HGS. The subjects were then allocated to the low HGS, asymmetrical HGS, and combined low and asymmetrical HGS (BOTH group) groups, and those with neither low nor asymmetric HGS (the normal group). The InBody 770 instrument was used for the analysis of muscle mass, with low muscle mass defined as a skeletal muscle mass index (SMI) of < 7.0 kg/m2 or < 5.7 kg/m2 for males and females, respectively. The associations between the different HGS groups and low muscle mass were assessed by logistic regression analysis.

RESULTS

The study included 1748 subjects, of whom 1272 (72.77%) were over the age of 60 years. The numbers of Han, Tibetan, and Qiang were 885 (50.63%), 217 (12.41%), and 579 (33.12%), respectively. A total of 465 individuals (26.60%) were classified as having low muscle mass, while 228 (13.04%), 536 (30.66%), and 125 (7.15%) participants were allocated to the low HGS, asymmetric HGS, and BOTH groups, respectively. The average SMI differed significantly between the normal group and the other groups (normal group vs. asymmetric HGS group vs. low HGS group vs. BOTH group: 6.627 kg/m2 vs. 6.633 kg/m2 vs. 6.492 kg/m2 vs. 5.995 kg/m2, respectively, P < 0.05). In addition, the prevalence of low muscle mass in the normal, asymmetric HGS, low HGS, and BOTH groups increased sequentially, with significant differences (normal group vs. asymmetric HGS group vs. low HGS group vs. BOTH group: 21.5% vs. 22.4% vs. 39.5% vs. 56%, respectively, P = 0.001). Further logistic regression analysis showed that the presence of low HGS (OR = 1.7, 95%CI: 1.203-2.402) and both low and asymmetric HGS (OR = 3.378, 95%CI: 2.173-5.252) were predictive of low muscle mass, with the chance being higher for the latter condition.

CONCLUSION

The findings suggest that although asymmetrical HGS itself does not increase the chances of low muscle mass. When low HGS and a combination of both features (low HGS combined with asymmetric HGS) is present in subjects, the chance of low muscle mass increases.

Associations of micronutrient dietary patterns with sarcopenia among US adults: a population-based study

Background

Current epidemiological evidence points to an association between micronutrient (MN) intake and sarcopenia, but studies have focused on single MN, and no combined effects on MNs have been reported. The aim of this study was to investigate the relationship between different MN intake patterns and sarcopenia and skeletal muscle mass.

Methods

We performed a population-based cross-sectional study, with a total of 5,256 U.S. adults aged 20-59 years, and we collected total daily MN intake and appendicular skeletal muscle mass measured by Dual-Energy X-ray Absorptiometry (DXA). Principal component analysis (PCA) was used to obtain nutrient patterns and principal component scores based on the intake of 14 MNs, and logistic regression analysis was used to assess the effects of single MN and MN intake patterns on sarcopenia and muscle mass.

Results

We defined three MN intake patterns by PCA: (1) adherence to VitB-mineral, high intake of vitamin B and minerals; (2) adherence to VitAD-Ca-VB12, high intake of vitamin A, vitamin D, calcium and vitamin B12; and (3) adherence to Antioxidant Vit, high intake of antioxidant vitamins A, C, E, and K. These three nutrient patterns explained 73.26% of the variance of the population. A negative association was observed between most single MN intakes and sarcopenia, and after adjusting for confounders, adherence to the highest tertile of the three nutrient patterns was associated with a lower risk of sarcopenia and relatively higher skeletal muscle mass compared to the lowest adherence. In subgroup analysis, MN intake patterns were significantly correlated with sarcopenia in middle-aged females.

Conclusion

Nutritional patterns based on MN intake were significantly related to sarcopenia, indicating that MNs interact with each other while exerting their individual functions, and that MN dietary patterns may provide promising strategies for preventing the loss of muscle mass, with further prospective studies warranted in the future.

Relationship between neck vessel abnormalities and sarcopenia: results of a study examining trends in health and aging in western China

OBJECTIVE

To elucidate the association between cervical vascular abnormalities (high Crouse score, high carotid intima-media thickness [CIMT], high plaque score [PS]) and sarcopenia and its diagnostic elements.

STUDY DESIGN

This cross-sectional investigation selected patients from the Western China Health and Aging Trends Study (WCHAT) aged 60 years and older. High CIMT and high Crouse score was defined as values ≥ upper quartile cutoff. Moreover, PS ≥ 3 was set as an high PS. Sarcopenia diagnosis and the definition of sarcopenia diagnostic elements were based on the Asian Working Group on Sarcopenia (AWGS) 2019 consensus. Lastly, associations between high Crouse score, high PS, high CIMT, and sarcopenia and its diagnostic elements were assessed using logistic regression.

RESULT

In all, we recruited 932 subjects in this study, among which, 138 people (14.81%) were diagnosed with sarcopenia. The rates of high Crouse score (sarcopenia vs. non-sarcopenia: 37.68% vs. 23.30%, P < 0.001) and high PS (sarcopenia vs. non-sarcopenia: 34.78% vs. 18.39%, P < 0.001) in subjects with sarcopenia were higher than those in subjects without sarcopenia. Logistic regression analysis and the correction of possible confounding factors showed that high Crouse score and high PS were related to sarcopenia (high Crouse score: OR = 1.573; 95%CI: 1.032-2.4; high PS: OR = 1.845; 95%CI: 1.195-2.851). Further analysis indicated that high Crouse score were associated with low muscle mass (OR = 1.403; 95%CI: 1.002-1.966) and low physical function (OR = 1.93; 95%CI: 1.3-2.866). High PS was found to be related to low physical function (OR = 1.83; 95%CI: 1.209-2.771).

CONCLUSION

While both high Crouse score and high PS are related to sarcopenia, further analysis showed that high Crouse score were mainly associated with low muscle mass and low physical function while high PS was associated with low physical function.

Analysis of intestinal flora in elderly Uygur patients with sarcopenia

OBJECTIVE

This study was designed to analyze the structural characteristics of the intestinal flora of elderly Uygur patients with sarcopenia, thereby providing new ideas for clinical treatment.

METHODS

Firstly, fecal samples were collected from 40 elderly Uygur patients with sarcopenia (Sarcopenia group) and 40 healthy people (Control group). Next, significant differences in the intestinal flora between the two groups were analyzed based on 16S rDNA high-throughput sequencing. The linear discriminant analysis effect size (LEfSe) was used to estimate the magnitude of the effect of each component (species) abundance on the differential effect. Additionally, an analysis was also performed on the relationship between the intestinal flora and the cytokines in the peripheral blood of patients with sarcopenia.

RESULTS

The results of β diversity showed that there were differences in the structure of the intestinal flora between the two groups. Besides, the phylum level of intestinal flora between the two groups was not significantly different. However, the difference was significant in the intestinal flora at the order, family, and genus levels between the two groups. Among them, Lachnoclostridium, Photobacterium, Anaerobic Bacillus, Hydrogenophilus, and Eubacterium were enriched in the Sarcopenia group; Prevotella 9, Firmicutes FCS020 group, Streptobacillus, Aggregatibacter, Corynebacterium, Clostridium Difficile, and Haloanaerobium were enriched in the Control group. The LEfSe outcomes further showed that Lachnoclostridium was highly enriched in the Sarcopenia group; Prevotella 9 and Firmicutes FCS020 group were significantly enriched in the Control group. Furthermore, the relative abundance of Lachnoclostridium and Streptobacillus were significantly different in patients with high and low IL-6 levels.

CONCLUSION

In conclusion, Lachnoclostridium is significantly enriched in the intestines of elderly Uygur patients with sarcopenia; the increase in Lachnoclostridium abundance and the decrease in Streptobacillus abundance are associated with high levels of IL-6. Therefore, abnormal intestinal flora is related to inflammatory reflexes in patients with sarcopenia.

Relationship of Serum 25-Hydroxyvitamin D Levels With Sarcopenia and Body Composition in Community-Dwelling Older Adults: A Paired Case-Control Study

OBJECTIVE

Sarcopenia is a leading health problem among older adults. However, few studies have explored the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels, sarcopenia, and body composition in older Chinese individuals. The aim of this study was to investigate the relationship of serum 25(OH)D levels with sarcopenia, sarcopenia indices, and body composition in community-dwelling older Chinese adults.

DESIGN

Paired case-control study.

SETTING AND PARTICIPANTS

This case-control study enrolled 66 older adults newly diagnosed with sarcopenia (sarcopenia group) and 66 older adults without sarcopenia (non-sarcopenia group) after screening in the community.

METHODS

The definition of sarcopenia was based on the Asian Working Group for Sarcopenia 2019 criteria. Serum levels of 25(OH)D were measured using an enzyme-linked immunosorbent assay. Conditional logistic regression analysis was performed to estimate odds ratios (ORs) and 95% CIs. Spearman's correlation was used to examine the correlations among sarcopenia indices, body composition, and serum 25(OH)D.

RESULTS

Serum 25(OH)D levels were significantly lower in the sarcopenia group (29.08 ± 15.11 ng/mL) than in the non-sarcopenia group (36.28 ± 14.68 ng/mL) (P < .05). Vitamin D deficiency was associated with an increased risk of sarcopenia (OR, 7.749; 95% CI, 1.955-30.714). Serum 25(OH)D levels in men were positively correlated with skeletal muscle mass index (SMI) (r = 0.450; P < .001) and negatively correlated with gait speed (r = -0.282; P = .032). Serum 25(OH)D levels in women were positively correlated with SMI (r = 0.286; P < .001), skeletal muscle mass (r = 0.395; P < .001), and fat-free mass (r = 0.412; P < .001).

CONCLUSIONS AND IMPLICATIONS

Serum 25(OH)D levels were lower in older adults with sarcopenia than those in adults without sarcopenia. Vitamin D deficiency was associated with increased risk of sarcopenia, and serum 25(OH)D levels were positively correlated with SMI.

"Diet for the prevention and management of sarcopenia"

Sarcopenia is a geriatric condition characterized by a progressive loss of skeletal muscle mass and strength, with an increased risk of adverse health outcomes (e.g., falls, disability, institutionalization, reduced quality of life, mortality). Pharmacological remedies are currently unavailable for preventing the development of sarcopenia, halting its progression, or impeding its negative health outcomes. The most effective strategies to contrast sarcopenia rely on the adoption of healthier lifestyle behaviors, including adherence to high-quality diets and regular physical activity. In this review, the role of nutrition in the prevention and management of sarcopenia is summarized. Special attention is given to current "blockbuster" dietary regimes and agents used to counteract age-related muscle wasting, together with their putative mechanisms of action. Issues related to the design and implementation of effective nutritional strategies are discussed, with a focus on unanswered questions on the most appropriate timing of nutritional interventions to preserve muscle health and function into old age. A brief description is also provided on new technologies that can facilitate the development and implementation of personalized nutrition plans to contrast sarcopenia.

The Vitamin D/Vitamin D receptor (VDR) axis in muscle atrophy and sarcopenia

Muscle atrophy and sarcopenia (the term given to the age-related decline in muscle mass and function), influence an individuals risk of falls, frailty, functional decline, and, ultimately, impaired quality of life. Vitamin D deficiency (low serum levels of 25-hydroxyvitamin D (25(OH)D₃)) has been reported to impair muscle strength and increase risk of sarcopenia. The mechanisms that underpin the link between low 25(OH)D₃ and sarcopenia are yet to be fully understood but several lines of evidence have highlighted the importance of both genomic and non-genomic effects of active vitamin D (1,25-dihydroxyvitamin D (1,25(OH)₂D₃)) and its nuclear vitamin D receptor (VDR), in skeletal muscle functioning. Studies in vitro have demonstrated a key role for the vitamin D/VDR axis in regulating biological processes central to sarcopenic muscle atrophy, such as proteolysis, mitochondrial function, cellular senescence, and adiposity. The aim of this review is to provide a mechanistic overview of the proposed mechanisms for the vitamin D/VDR axis in sarcopenic muscle atrophy.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.

High Serum AST/ALT Ratio and Low Serum INS*PA Product Are Risk Factors and Can Diagnose Sarcopenia in Middle-Aged and Older Adults

BACKGROUND

Sarcopenia is an age-related clinical condition and associated with an increased risk of adverse outcomes. However, to date, there is no global standard for the diagnosis of sarcopenia, and fewer serum biomarkers have been suggested for the diagnosis of sarcopenia. It is, thus, important that sarcopenia-related serological diagnostic markers be explored. The present study was based on the Asian Working Group on Sarcopenia 2019 (AWGS 2019) criteria to assess whether aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio and fasting insulin*prealbumin (INS*PA) product are diagnostic markers associated with sarcopenia in various ethnic groups in western China.

METHODS

This cross-sectional study included 4,099 adults (1,471 men and 2,628 women) from the West China Health and Aging Trend (WCHAT) study. The value of serum biomarkers was based on laboratory data. The accompanying metabolic disorders and the associated parameters were evaluated. Logistic regression analysis was used to explore the association between markers and sarcopenia. Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic efficacy of the test in differentiating sarcopenia.

RESULTS

Binary regression analysis showed that high serum AST/ALT (OR = 2.247) and adrenal cortisol (PTC, OR = 1.511), low serum INS*PA (OR = 2.970), free triiodothyronine (FT3, OR = 1.313), 25-OH-VitD (VitD, in male participants, OR = 1.817), and diastolic blood pressure (DBP, in female subjects, OR = 1.250) were independent risk factors for sarcopenia (P < 0.05). AST/ALT and INS*PA were not affected by metabolic factors and had better diagnostic efficacy for sarcopenia. The AUC of the INS*PA was the highest (0.705, 0.706, and 0.701, respectively, P < 0.05), followed by that of the AST/ALT (0.680, 0.675, and 0.695, respectively, P < 0.05). The AUC of the AST/ALT/(INS*PA)*10,000 used to diagnose sarcopenia was 0.727.

CONCLUSION

Among middle-aged and older adults of multiple ethnicities in western China, we found that higher AST/ALT and lower INS*PA levels are associated with an increased prevalence of sarcopenia. Since these serum biomarkers are inexpensive and can be obtained easily from biochemical routine, regular follow-up of AST/ALT and INS*PA may be an effective strategy in sarcopenia screening and management.