Sarcopenic obesity is associated with telomere shortening: findings from the NHANES 1999-2002

Leukocyte telomere length and sarcopenia-related traits: A bidirectional Mendelian randomization study

Accumulating evidence indicated that leukocyte telomere length (LTL) was related to sarcopenia. However, it is still not clear whether the association of changes in LTL with sarcopenia is likely to be causal, or could be explained by reverse causality. Thus, we carried on bidirectional Mendelian randomization (MR) and multivariable MR analyses to identify the causal relationship between LTL and sarcopenia-related traits. Summary-level data and independent variants used as instruments came from large genome-wide association studies of LTL (472,174 participants), appendicular lean mass (450,243 participants), low grip strength (256,523 participants), and walking pace (450,967 participants). We identified suggestive association of longer LTL with larger appendicular lean mass [odds ratio (OR) = 1.053; 95% confidence interval (CI), 1.009-1.099; P = 0.018], and causal association of longer LTL with a lower risk of low grip strength (OR = 0.915; 95% CI, 0.860-0.974; P = 0.005). In the reverse MR analysis, we also observed a positive causal association between walking pace and LTL (OR = 1.252; 95% CI, 1.121-1.397; P < 0.001). Similar results can be repeated in sensitivity analyses. While in the multivariable MR analysis, the estimate of the impact of walking pace on LTL underwent a transformation after adjusting for T2DM (OR = 1.141; 95%CI: 0.989-1.317; P = 0.070). The current MR analysis supported a causal relationship between shorter telomere length and both low muscle mass and strength. Additionally, walking pace may affect LTL through T2DM.

Publication trends in nutrition research for sarcopenic obesity: A 20-year bibliometric analysis

BACKGROUND

We used bibliometric methods to evaluate publications on the role of nutrition in sarcopenic obesity and analyzed the current situation and developmental trends over the past 2 decades.

METHODS

Publications from 2002 to 2022 related to the role of nutrition in sarcopenic obesity were extracted from the Web of Science Core Collection database. CiteSpace, VOSviewer, and the Bibliometrix R package were applied to build relevant network diagrams.

RESULTS

One thousand ninety-four articles from 64 countries were included. The annual number of publications in this field has shown an intense growth trend. The University of Alberta, Yonsei University, and Korea University are the major research institutions. Clinical Nutrition has published the most papers on the role of nutrition in sarcopenic obesity, and the American Journal of Clinical Nutrition is the most co-cited journal. A total of 5834 authors conducted the relevant studies. Yves Boirie has published the most papers in this field, and AJ Cruz-Jentoft is the most co-cited author.

CONCLUSION

This is the first bibliometric study of the role of nutrition in sarcopenic obesity. This study systematically summarizes the research hotspots and development directions in this field, and provides a reference for scholars studying the role of nutrition in sarcopenic obesity.

Aging, Physical Exercise, Telomeres, and Sarcopenia: A Narrative Review

Human aging is a gradual and adaptive process characterized by a decrease in the homeostatic response, leading to biochemical and molecular changes that are driven by hallmarks of aging, such as oxidative stress (OxS), chronic inflammation, and telomere shortening. One of the diseases associated with the hallmarks of aging, which has a great impact on functionality and quality of life, is sarcopenia. However, the relationship between telomere length, sarcopenia, and age-related mortality has not been extensively studied. Moderate physical exercise has been shown to have a positive effect on sarcopenia, decreasing OxS and inflammation, and inducing protective effects on telomeric DNA. This results in decreased DNA strand breaks, reduced OxS and IA, and activation of repair pathways. Higher levels of physical activity are associated with an apparent increase in telomere length. This review aims to present the current state of the art of knowledge on the effect of physical exercise on telomeric maintenance and activation of repair mechanisms in sarcopenia.

Association of weight range with telomere length: A retrospective cohort study

Objective

Previous research has shown a significant association between weight and telomere length, but did not take into consideration weight range. The study was to investigate the association of weight range with telomere length.

Methods

Data of 2918 eligible participants aged 25-84 years from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 cycle were analyzed. Information about demographic variables, lifestyle factors, anthropometric variables, and medical comorbidities were included. Univariate and multivariate linear regression model with adjustments for potential confounders were employed to determine the association between weight range and telomere length. A non-parametrically restricted cubic spline model was used to illustrate the possible non-linear relationship.

Results

In univariate linear regression, BMI_max, BMI range, and weight range all revealed significant negative associations with telomere length. However, annual rate of BMI/weight range showed a significant positive associations with telomere length. There was no significant association between telomere length and BMI_min. After adjusting for potential confounders, the inverse associations persisted in BMI_max (β=-0.003, P<0.001), BMI range (β=-0.002, P=0.003), and weight range (β=-0.001, P=0.001). Furthermore, annual rate of BMI range (β=-0.026, P=0.009) and weight range (β=-0.010, P=0.007) presented negative associations with telomere length, after adjusting for covariates in Model 2-4. The association between BMI_min (β =-0.002, P=0.237) and telomere length still could not reach statistical significance in multivariate linear regression model. The results of restricted cubic spline analysis showed that BMI_max (P for nonlinear =0.026), BMI range (P for nonlinear =0.022), weight range (P for nonlinear =0.035), annual rate of BMI range (P for nonlinear =0.030), and annual rate of weight range (P for nonlinear =0.027) all had nonlinear inverse associations with telomere length.

Conclusions

The study suggests that weight range is inversely associated with telomere length in U.S. adults. Larger weight fluctuation may accelerate telomere shortening and aging.