Association between sarcopenia-related traits and cardiovascular diseases: a bi-directional Mendelian randomization study

Causal relationships of circulating amino acids with sarcopenia-related traits: A bidirectional Mendelian randomization study

BACKGROUND AND AIM

Recent studies have indicated a correlation between certain Amino acids (AAs) and sarcopenia. However, the exact causal relationship among these associations is still unclear. This study aims to elucidate the causal relationships between 20 types of AAs and the phenotypic characteristics associated with sarcopenia through Mendelian randomization (MR) analysis.

METHODS AND RESULTS

This MR study employed single nucleotide polymorphisms (SNPs) that were significantly associated with both AAs and the traits of sarcopenia as instrumental variables (IVs). The main method for estimating causal effects was the inverse-variance weighted (IVW) approach. To ensure the robustness of the findings, additional methods such as weighted median, weighted mode, and MR Egger regression were used. Sensitivity analyses included heterogeneity and pleiotropy tests. In this research, we discovered potential causal relationships between AAs and traits associated with sarcopenia. We not only found that AAs previously studied, such as Glutamine, Tyrosine, Glycine, and branched-chain amino acids, play positive roles in muscle metabolism. Additionally, our study identified the role of AAs previously neglected or not considered in earlier research, such as Alanine, Lysine, Cysteine, and Methionine, which exert potential effects on muscle metabolism and offer considerable research potential and value.

CONCLUSIONS

This MR study clarified the reciprocal effects between circulating levels of AAs and sarcopenia-related traits. These results indicate that AAs may be used as biomarkers for diagnosing sarcopenia or as intervention targets for its treatment in clinical practice.

Additive impact of metabolic syndrome and sarcopenia on all-cause and cause-specific mortality: an analysis of NHANES

Background

Metabolic syndrome (MetS) and sarcopenia (SP) are increasingly significant public health issues in aging societies, sharing common pathophysiological mechanisms and being associated with severe health consequences. This study investigates the impact of MetS and SP on all-cause and cause-specific mortality using a longitudinal, nationally representative population-based cohort.

Methods

The study analyzed data from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2018. Mortality data were obtained from the National Death Index up to December 2019.

Results

Among the 21,962 participants, 13,517 (61.5%) had neither MetS nor SP(MetS-/SP-), 5,407 (24.6%) had MetS only(MetS+/SP-), 2,698 (12.2%) had SP only(MetS-/SP+), and 340 (1.5%) had both MetS and SP(MetS+/SP+). Compared to the group without MetS and SP, the groups with MetS only, SP only, and both MetS and SP showed increased all-cause mortality, with adjusted hazard ratios (HR) of 1.23 (95% CI: 1.11-1.37), 1.63 (95% CI: 1.41-1.89), and 1.61 (95% CI: 1.33-1.95), respectively. The MetS+/SP+ group had the highest overall mortality risk (trend test p<0.0001). For cause-specific mortality, the MetS+/SP+ group exhibited increased cardiovascular mortality (HR: 1.89, 95% CI: 1.27-2.81), cardiac mortality (HR: 1.89, 95% CI: 1.25-2.86), respiratory mortality (HR: 2.63, 95% CI: 1.29-5.35), and diabetes mortality (HR: 8.79, 95% CI: 2.62-29.45) compared to the group without MetS and SP.

Conclusion

The coexistence of MetS and SP significantly increases the risk of all-cause and cause-specific mortality. Individuals with either condition may require more vigilant management to prevent the onset of the other condition, thereby reducing mortality rates. These findings highlight the importance of integrated healthcare strategies targeting both MetS and SP to improve patient outcomes and longevity.

Occurrence of sarcopenia in elderly patients with coronary heart disease and its association with short-term prognosis

OBJECTIVE

Sarcopenia is a common complication in elderly patients with coronary heart disease (CHD). This study aims to analyse and explore the occurrence of sarcopenia in elderly patients with CHD and its associations with short-term prognosis.

METHODS

A total of 318 elderly patients with CHD were enrolled between March 2020 and March 2022. Sarcopenia was assessed at admission using grip strength and gait speed; subsequently, clinical data, cardiac function indicators, adverse events and mortality were compared between the two groups to explore the associations of sarcopenia with the short-term prognosis of elderly patients with CHD.

RESULTS

Among the 318 elderly patients with CHD included in this study, 69 developed sarcopenia, with an incidence rate of 21.70%. The sarcopenia group showed lower cardiac output and left ventricular ejection fraction levels than the non-sarcopenia group, while higher left ventricular end-diastolic diameter, left ventricular end-systolic diameter, interventricular septum thickness and left ventricular posterior wall thickness levels were greater than in the non-sarcopenia group, with p < 0.05. The sarcopenia group had higher rates of unconventional medical visits and major adverse cardiac and cerebral events compared with the non-sarcopenia group, with p < 0.05. The mortality rate in the sarcopenia group was higher than in the non-sarcopenia group, with p < 0.05.

CONCLUSION

Sarcopenia is significantly associated with the short-term prognosis of elderly coronary heart disease patients, indicating the need for preventive strategies to improve clinical outcomes and extend survival.

Hand grip strength and all-cause mortality risk in individuals with decreased bone mass: a study from NHANES database

Objective

Previous studies have demonstrated that grip strength is associated with various health outcomes, including osteoporosis. However, the impact of grip strength on long-term mortality risk among individuals with low bone mass remains unclear. This study aims to investigate the association between grip strength and the risk of all-cause mortality in the population with low bone mass.

Methods

We included 1,343 cases of decreased bone mass from the NHANES database spanning 2013 to 2014. All-cause mortality data were ascertained through linkage with national death index records up to December 31, 2015. Analysis was conducted using the Cox proportional hazards regression model, and we assessed result reliability through various model adjustments and hierarchical analyses, Schoenfeld's global and individual tests are utilized to estimate the time-varying covariance in the Cox proportional hazards regression model's hypothesis.

Results

Throughout an average follow-up period of 69.5 months, 148 deaths were documented. After adjusting for covariates, a significant association between grip strength and the risk of all-cause mortality was observed in individuals with decreased bone mass (HR = 0.9, 95% CI: 0.87-0.93, p < 0.001). Individuals with normal grip strength, compared to those with low grip strength, exhibited a 56% lower risk of all-cause mortality (HR = 0.44, 95% CI: 0.29-0.67, p < 0.001). Various models consistently demonstrated similar significant trends post-adjustment. Subgroup analysis revealed an interaction between grip strength and coronary heart disease (p < 0.05). Schoenfeld's global and individual tests confirmed the reliability of the model (p > 0.05).

Conclusion

Our findings indicate that low grip strength is associated with increased all-cause mortality risk in individuals with decreased bone mass. The inclusion of routine monitoring of grip strength in patients with osteopenia and the encouragement of maintaining or improving grip strength in this population may offer a novel approach to health management for these individuals.

Individual and joint association of Life's Essential 8 metrics with pre-sarcopenia among U.S. adults

BACKGROUND

In recent times, the American Heart Association has updated its approach to evaluating cardiovascular health (CVH) by replacing the previous "Life's Simple 7" with the more demanding "Life's Essential 8" (LE8). However, the impact of enhancing CVH on reducing the risk of pre-sarcopenia and the association of LE8 metrics with pre-sarcopenia remain unexplored.

METHODS

LE8 score was calculated among 9857 participants. Multivariable logistic regression was utilized to investigate the associations between LE8 and pre-sarcopenia. Additionally, the weighted quantile sum (WQS) model was employed to determine the combined and individual impact of LE8 metrics on pre-sarcopenia. To assess the indirect effects of peripheral immune responses on the relationships between cardiovascular health and pre-sarcopenia, mediation analyses were performed.

RESULTS

In this study, 827 participants had pre-sarcopenia. After accounting for potential confounding factors, the group with excellent cardiovascular health demonstrated an 83% lower risk of pre-sarcopenia compared to the poor cardiovascular health group (OR: 0.17, 95% CI: 0.11-0.27) and a 33% decreased risk of pre-sarcopenia for each 10-point increase in LE8 score (OR: 0.67, 95% CI: 0.62-0.73). Body mass index (BMI) and physical activity (PA) were the critical contributors that decreased the prevalence of pre-sarcopenia in the obese and non-obese populations, respectively.

CONCLUSIONS

A negative association was found between LE8 score and pre-sarcopenia prevalence. Body mass index and physical activity are the primary contributors to the obese and non-obese populations, respectively.

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

Background

Recent research has indicated a potential association between thyroid function and sarcopenia, but the specific mechanisms and a definitive causal relationship have yet to be established. Therefore, the objective of this study is to examine the potential causal connection between thyroid function and sarcopenia-related traits, including hand-grip strength, appendicular lean mass (ALM), and walking pace.

Methods

The study used a bi-directional two-sample MR design, with thyroid function examined as the exposure and sarcopenia-related traits as the outcome in the first stage, and then reversed in the second stage. The genetic instruments for thyroid function were obtained from a comprehensive meta-analysis involving 271,040 participants. Data on sarcopenia-related traits based on GWASs were collected from the UK Biobank, which includes up to 461,026 European participants. The estimates for MR were calculated using the inverse-variance weighted (IVW) method, and several sensitivity analyses were performed.

Results

After applying the Bonferroni correction for multiple testing, our MR analyses revealed no significant impact of thyroid function liability on sarcopenia-related traits. Similarly, our reverse MR analysis did not provide evidence supporting the influence of liability to sarcopenia-related traits on thyroid function. The results of the primary IVW MR analyses were largely in line with those obtained from our sensitivity MR analyses.

Conclusion

Our research findings do not suggest a link between thyroid function and sarcopenia-related traits. The associations identified in epidemiological studies may be influenced, at least in part, by shared biological mechanisms or environmental confounders.

Association of atherogenic index of plasma and triglyceride glucose-body mass index and sarcopenia in adults from 20 to 59: a cross-sectional study

Background

The relationship between atherogenic index of plasma (AIP) and triglyceride glucose-body mass index (TyG-BMI) and sarcopenia has not been studied in the United States (US) population.

Methods

This research included 4,835 people from the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2018. The relationship between sarcopenia and TyG-BMI, as well as the AIP index, was examined through the utilization of restricted cubic spline (RCS) analysis, subgroup analysis, and multivariate logistic regression analysis. Diagnostic value of AIP and TyG-BMI for sarcopenia was compared by receiver operating characteristic (ROC) curves.

Results

In this research, 428 people with sarcopenia were identified among the 4,835 subjects that were included in the experiment. AIP and sarcopenia were positively associated with an odds ratio (OR) of 1.58 and a 95% confidence interval (CI) of (1.07, 2.34) on fully adjusted multivariate logistic regression analysis. Similarly, TyG-BMI and sarcopenia were positively associated with an OR of 8.83 and a 95% CI of (5.46, 14.26). AIP and sarcopenia had a non-linear positive connection (P-value<0.001, P-Nonlinear=0.010), while TyG-BMI and sarcopenia had a linear positive correlation (P-value<0.001, P-Nonlinear=0.064), according to RCS analysis. Subgroup analyses showed a significant interaction between TyG-BMI and sarcopenia due to gender (P = 0.023). ROC curves showed that TyG-BMI (AUC:0.738, 95% CI: 0.714 - 0.761) was more useful than AIP (AUC:0.648, 95% CI: 0.622 - 0.673) in diagnosing sarcopenia.

Conclusion

In US adults aged 20-59 years, our study revealed a correlation between elevated AIP and TyG-BMI levels and heightened sarcopenia risk. Moreover, TyG-BMI has better diagnostic validity than AIP.

Association between relative muscle strength and cardiovascular disease among middle-aged and older adults in China

BACKGROUND

The association between sarcopenia and cardiovascular disease (CVD) is well known. However, the clinical diagnosis of sarcopenia is complex and not suitable for early clinical identification and prevention of CVD. Relative muscle strength (RMS) is a relatively quantitative and straightforward indicator, but its association with CVD remains unclear. Hence, the objective of this research was to investigate the correlation between RMS and CVD incidence.

METHODS

This was a cross-sectional study, using data from the China Health and Retirement Longitudinal Study (CHARLS) in 2011. CVD events were assessed through self-reported physician diagnoses. The RMS was determined by dividing the maximum grip strength by the appendicular skeletal muscle mass (ASM). This study used multivariate logistic regression and restricted cubic spline (RCS) curves to explore the correlation between RMS and CVD incidence. Additionally, we conducted subgroup analyses to provide additional evidence supporting the association between the two variables.

RESULTS

A total of 8,733 people were included in our study, with 1,152 (13.19%) CVD patients and 7,581 (86.81%) non-CVD patients. When the data were grouped according to quartiles (Q) of RMS, the inverse association between CVD and RMS remained statistically significant even after controlling for all potential confounding factors. Compared with participants in Q1 of RMS, the ORs (95% CIs) of CVD among those in Q2-Q4 were 0.99 (0.83, 1.17), 0.81 (0.67, 0.98), and 0.70 (0.57, 0.85), respectively. Moreover, the RCS results showed a negative linear correlation between the RMS and CVD incidence (P for nonlinearity = 0.555). Subgroup analysis revealed no significant interaction in any of the groups except for the sex group (P for interaction = 0.046).

CONCLUSION

Our study indicated a stable negative correlation between RMS and CVD incidence. RMS is helpful for the early identification and prevention of CVD.

Osteoporosis and coronary heart disease: a bi-directional Mendelian randomization study

Background

Osteoporosis (OP) and cardiovascular disease (CVD) are major global public health issues, especially exacerbated by the challenges of an aging population. As these problems intensify, the associated burden on global health is expected to increase significantly. Despite extensive epidemiological investigations into the potential association between OP and CVD, establishing a clear causal relationship remains elusive.

Methods

Instrumental variables were selected from summary statistics of the IEU GWAS database. Five different components of BMD (heel BMD, LS BMD, FA BMD, FN BMD, and TB BMD) were used as OP phenotypes. CHD, MI, and stroke were selected to represent CVD. Multiple analysis methods were used to evaluate the causal relationship between CVD and OP comprehensively. In addition, sensitivity analyses(Cochran's Q test, MR-Egger intercept test, and "leave one out" analysis) were performed to verify the reliability of the results.

Results

The MR showed a significant causal relationship between CHD on heel BMD and TB BMD; in the reverse analysis, there was no evidence that OP has a significant causal effect on CVD. The reliability of the results was confirmed through sensitivity analysis.

Conclusion

The study results revealed that CHD was causally associated with Heel BMD and TB BMD, while in the reverse MR analysis, the causal relationship between OP and CVD was not supported. This result posits CHD as a potential etiological factor for OP and prompts that routine bone density assessment at traditional sites (forearm, femoral neck, lumbar spine) using DAX may inadequately discern underlying osteoporosis issues in CHD patients. The recommendation is to synergistically incorporate heel ultrasound or DAX for total body bone density examinations, ensuring clinical diagnostics are both precise and reliable. Moreover, these findings provide valuable insights for public health, contributing to the development of pertinent prevention and treatment strategies.

Systemic immune-inflammation index and all-cause and cause-specific mortality in sarcopenia: a study from National Health and Nutrition Examination Survey 1999-2018

Background

Sarcopenia, common in the elderly, often linked to chronic diseases, correlates with inflammation.The association between SII and mortality in sarcopenia patients is underexplored, this study investigates this relationship in a U.S. adult cohort.

Methods

We analyzed 1999-2018 NHANES data, focusing on 2,974 adults with sarcopenia. Mortality outcomes were determined by linking to National Death Index (NDI) records up to December 31, 2019. Using a weighted sampling design, participants were grouped into three groups by the Systemic Immune-Inflammation Index (SII). We used Cox regression models, adjusting for demographic and clinical variables, to explore SII's association with all-cause and cause-specific mortality in sarcopenia, performing sensitivity analyses for robustness.

Results

Over a median follow-up of 9.2 years, 829 deaths occurred. Kaplan-Meier analysis showed significant survival differences across SII groups. The highest SII group showed higher hazard ratios (HRs) for all-cause and cause-specific mortality in both crude and adjusted models. The highest SII group had a higher HR for all-cause(1.57, 1.25-1.98), cardiovascular(1.61, 1.00-2.58), cancer(2.13, 1.32-3.44), and respiratory disease mortality(3.21, 1.66-6.19) in fully adjusted models. Subgroup analyses revealed SII's association with all-cause mortality across various demographics, including age, gender, and presence of diabetes or cardiovascular disease. Sensitivity analyses, excluding participants with cardiovascular diseases, those who died within two years of follow-up, or those under 45 years of age, largely reflected these results, with the highest SII group consistently demonstrating higher HRs for all types of mortality in both unadjusted and adjusted models.

Conclusion

Our study is the first to demonstrate a significant relationship between SII and increased mortality risks in a sarcopenia population.

Targeting cardiac and cerebrovascular risks of sarcopenia: Is it time to screen for muscle health?

This Editorial comments on the article by Jauffret et al. in this issue.