Causal linkage of tobacco smoking with ageing: Mendelian randomization analysis towards telomere attrition and sarcopenia

Associations between modifiable risk factors and frailty progression among individuals with pre-frailty

BACKGROUND

In the context of the present global aging phenomenon, the senior population and pace of aging in China have emerged as prominent issues on the worldwide stage. Frailty, a complicated condition that is closely linked to the clinical syndrome of advancing age, poses a considerable health risk to older individuals. Frailty status was assessed by the frailty index (FI) ranging from 0 to 1, pre-frailty was defined as >0.10 to <0.25, and frailty was defined as ≥0.25. To look at the connection between modifiable risk factors and frailty progression among individuals in the pre-frailty population.

METHODS

Using pre-frailty patients as characterized by the 32-frailty index, the study focused on middle-aged and elderly persons from China and ultimately recruited 5,411 participants for analysis. The relationship between modifiable factors and changes in pre-frailty status throughout follow-up was investigated. Modifiable factors were body mass index (BMI), abdominal obesity, smoking status, alcohol use, and sleep status. We employed logistic regression to examine the relationships between modifiable risk factors and changes in pre-frailty status, as well as the associations between modifiable factors scores and the corresponding pre-frailty progression. Additionally, we generated the modifiable factors scores and examined how these related to modifications in the pre-frailty stage.

RESULTS

In this study, after a mean follow-up of 6 years, (OR = 0.59, 95%CI: 0.48-0.71) for BMI ≥ 25 kg/m2 and (OR = 0.74, 95%CI: 0.63-0.89) for concomitant abdominal obesity were significantly associated with lower reversal to a healthy state; (OR = 1.24, 95%CI:1.07-1.44) and (OR = 1.25, 95%CI: 1.10-1.42) for the group that negatively progressed further to frailty were significantly associated with increased frailty progression profile. Subsequently, investigation of modifiable factor scores and changes of pre-frailty status found that as scores increased further, frailty developed (OR = 1.12, 95%CI:1.05-1.18), with scores of 3 and 4 of (OR = 1.38, 95%CI: 1.08-1.77) and (OR = 1.52, 95%CI:1.09-2.14). Finally, we also performed a series of stratified analyses and found that rural unmarried men aged 45 to 60 years with less than a high school degree were more likely to develop a frailty state once they developed abdominal obesity.

CONCLUSION

In pre-frailty individuals, maintaining more favorable controllable variables considerably enhances the chance of return to normal and, conversely, increase the risk of progressing to the frailty.

Mapping the causal associations of cytokines with sarcopenia and aging traits: Evidence from bidirectional Mendelian randomization

BACKGROUND

Cytokines and growth factors may serve as a bridge in studying the causal relationships between inflammaging and sarcopenia due to their roles in inflammaging. In this study, we aim to explore the causal association of cytokines with sarcopenia and aging traits and further identify the significant inflammation factors.

METHODS

Bidirectional Mendelian randomization (MR) analysis was used to identify the causality. Forty-one kinds of circulation cytokines and growth factors were set as exposures, and the data were from a summary genome-wide association study (GWAS) containing three cohorts with 8293 healthy participants of European ancestry from 1983 to 2011. Hand grip strength, adjusted appendicular lean mass (AALM), usual walking pace, moderate-to-vigorous physical activity (MVPA) levels, able to walk or cycle unaided for 10 min (AWCU10) and telomere length were selected as outcomes. Data for outcomes were obtained from meta-GWAS and the UK Biobank, and sample sizes ranged from 69 537 to 472 174. Low hand grip strength was defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and Foundation for the National Institutes of Health (FNIH) cut-off points, respectively. Other outcome traits were defined and measured according to the UK Biobank and raw cohorts' criteria. We set two significance thresholds for single nucleotide polymorphisms (SNPs) associated with exposures to obtain adequate SNPs (5 × 10-6 and 5 × 10-8). Inverse-variance weighted, MR-Egger and weighted median were employed to estimate the causality.

RESULTS

Twenty-seven factors were identified to relate to sarcopenia and aging traits causally, and most were associated with only one outcome trait. IL16 (interleukin-16), CTACK (cutaneous T-cell attracting chemokine), MIP1b (macrophage inflammatory protein 1b) and PDGFbb (platelet-derived growth factor BB) were proven to relate causally to at least one sarcopenia and aging trait in both analyses with two significance thresholds. IL16 was causally associated with hand grip strength (0.977 [0.956-0.998] for EWGSOP and 0.933 [0.874-0.996] for FNIH), AALM (0.991 [0.984, 0.998]), MVPA (0.997 [0.995-1.000]) and AWCU10 (1.008 [1.003-1.013]). CTACK was proven to relate causally to hand grip strength (1.013 [1.007-1.019] for EWGSOP and 1.090 [1.041-1.142] for FNIH), AWCU10 (0.990 [0.986-0.994]) and telomere length (0.998 [0.983-0.994]). The results indicated that MIP1b has a causal effect on hand grip strength (1.032 [1.001-1.063] for EWGSOP), AWCU10 (0.994 [0.988-1.000] and 0.993 [0.988-0.998]) and telomere length (1.006 [1.000-1.012]). PDGFbb may causally relate to AALM (1.016 [1.001-1.030]) and telomere length (1.011 [1.007-1.015]). Reserve MR analyses also proved their unidirectional causal effects.

CONCLUSIONS

Twenty-seven factors were causally related to sarcopenia and aging traits, and the causal effects of IL16, CTACK, MIP1b and PDGFbb were proven in both analyses with two significance thresholds.

Breaking down causes, consequences, and mediating effects of telomere length variation on human health

BACKGROUND

Telomeres form repeated DNA sequences at the ends of chromosomes, which shorten with each cell division. Yet, factors modulating telomere attrition and the health consequences thereof are not fully understood. To address this, we leveraged data from 326,363 unrelated UK Biobank participants of European ancestry.

RESULTS

Using linear regression and bidirectional univariable and multivariable Mendelian randomization (MR), we elucidate the relationships between leukocyte telomere length (LTL) and 142 complex traits, including diseases, biomarkers, and lifestyle factors. We confirm that telomeres shorten with age and show a stronger decline in males than in females, with these factors contributing to the majority of the 5.4% of LTL variance explained by the phenome. MR reveals 23 traits modulating LTL. Smoking cessation and high educational attainment associate with longer LTL, while weekly alcohol intake, body mass index, urate levels, and female reproductive events, such as childbirth, associate with shorter LTL. We also identify 24 traits affected by LTL, with risk for cardiovascular, pulmonary, and some autoimmune diseases being increased by short LTL, while longer LTL increased risk for other autoimmune conditions and cancers. Through multivariable MR, we show that LTL may partially mediate the impact of educational attainment, body mass index, and female age at childbirth on proxied lifespan.

CONCLUSIONS

Our study sheds light on the modulators, consequences, and the mediatory role of telomeres, portraying an intricate relationship between LTL, diseases, lifestyle, and socio-economic factors.

Association between the oxidative balance score and low muscle mass in middle-aged US adults

Background

Oxidative Balance Score (OBS) is a tool for assessing the oxidative stress-related exposures of diet and lifestyle. The study aimed to investigate the association between OBS and low muscle mass.

Methods

Overall, 6,307 individuals over the age of 18 were assessed using data from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression and models were used, together with adjusted models.

Results

There was a negative relationship between OBS and low muscle mass [odds ratio (OR): 0.96, 95% confidence interval (CI): 0.94-0.97, p< 0.0001] using the first OBS level as reference. The values (all 95% CI) were 0.745 (0.527-1.054) for the second level, 0.650 (0.456-0.927) for the third level, and 0.326 (0.206-0.514) for the fourth level (P for trend <0.0001). Independent links with low muscle mass were found for diet and lifestyle factors. A restricted cubic spline model indicated a non-linear association between OBS and low muscle mass risk (P for non-linearity<0.05). In addition, the inflection points of the nonlinear curves for the relationship between OBS and risk of low muscle mass were 20.

Conclusion

OBS and low muscle mass were found to be significantly negatively correlated. By modulating oxidative balance, a healthy lifestyle and antioxidant rich diet could be a preventive strategy for low muscle mass.

Better Life's Essential 8 contributes to slowing the biological aging process: a cross-sectional study based on NHANES 2007-2010 data

Objective

To investigate the relationship between Life's Essential 8 (LE8) and Phenotypic Age Acceleration (PhenoAgeAccel) in United States adults and to explore the impact of LE8 on phenotypic biological aging, thereby providing references for public health policies and health education.

Methods

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2010, this cross-sectional study analyzed 7,339 adults aged 20 and above. Comprehensive assessments of LE8, PhenoAgeAccel, and research covariates were achieved through the integration of Demographics Data, Dietary Data, Laboratory Data, and Questionnaire Data derived from NHANES. Weighted generalized linear regression models and restricted cubic spline plots were employed to analyze the linear and non-linear associations between LE8 and PhenoAgeAccel, along with gender subgroup analysis and interaction effect testing.

Results

(1) Dividing the 2007-2010 NHANES cohort into quartiles based on LE8 unveiled significant disparities in age, gender, race, body mass index, education level, marital status, poverty-income ratio, smoking and drinking statuses, diabetes, hypertension, hyperlipidemia, phenotypic age, PhenoAgeAccel, and various biological markers (p < 0.05). Mean cell volume demonstrated no intergroup differences (p > 0.05). (2) The generalized linear regression weighted models revealed a more pronounced negative correlation between higher quartiles of LE8 (Q2, Q3, and Q4) and PhenoAgeAccel compared to the lowest LE8 quartile in both crude and fully adjusted models (p < 0.05). This trend was statistically significant (p < 0.001) in the full adjustment model. Gender subgroup analysis within the fully adjusted models exhibited a significant negative relationship between LE8 and PhenoAgeAccel in both male and female participants, with trend tests demonstrating significant results (p < 0.001 for males and p = 0.001 for females). (3) Restricted cubic spline (RCS) plots elucidated no significant non-linear trends between LE8 and PhenoAgeAccel overall and in gender subgroups (p for non-linear > 0.05). (4) Interaction effect tests denoted no interaction effects between the studied stratified variables such as age, gender, race, education level, and marital status on the relationship between LE8 and PhenoAgeAccel (p for interaction > 0.05). However, body mass index and diabetes manifested interaction effects (p for interaction < 0.05), suggesting that the influence of LE8 on PhenoAgeAccel might vary depending on an individual's BMI and diabetes status.

Conclusion

This study, based on NHANES data from 2007-2010, has revealed a significant negative correlation between LE8 and PhenoAgeAccel, emphasizing the importance of maintaining a healthy lifestyle in slowing down the biological aging process. Despite the limitations posed by the study's design and geographical constraints, these findings provide a scientific basis for the development of public health policies focused on healthy lifestyle practices. Future research should further investigate the causal mechanisms underlying the relationship between LE8 and PhenoAgeAccel and consider cross-cultural comparisons to enhance our understanding of healthy aging.

Methamphetamine use shortens telomere length in male adults and rats

BACKGROUND

Methamphetamine (MA) use increases the risk of age-related diseases. However, it remains uncertain whether MA use exhibits accelerated biological aging, as indicated by telomere length (TL), a proposed marker of aging. Here we conducted studies in both humans and rats to investigate the association between MA use and TL.

METHODS

We recruited 125 male MA users and 66 healthy controls, aged 30-40 years. MA users were diagnosed using DSM-5 criteria and categorized into two groups: non-severe (n = 78) and severe (n = 47) MA use disorder (MUD). MA-treated conditioned place preference (CPP) rats were utilized to validate our clinical investigations. TL was assessed using real-time polymerase chain reaction.

RESULTS

At clinical levels, MA users exhibited significantly shorter leukocyte TL compared to healthy controls. Among MA users, individuals with severe MUD had significantly shorter leukocyte TL than those with non-severe MUD. Importantly, both univariate and multivariate linear regression analyses demonstrated a negative association between the severity of MA use and leukocyte TL. In a rat model of MA-induced CPP, leukocyte TL was also significantly shortened after MA administration, especially in rats with higher CPP expression or reinstatement scores.

CONCLUSION

MA use shortened TL, and the severity of MA use was negatively correlated with TL. These findings provide new insights into the pathophysiology of accelerated aging caused by MA use and may have implications for identifying biomarkers and developing novel treatment strategies for MUD.

The association of depressive sarcopenia and cognitive decline among the elderly: Evidence from the Survey of Health and Retirement in Europe

OBJECTIVES

The present study aimed to explore the relationship between baseline different sarcopenia statuses combined with different depression statuses and long-term cognitive functions.

METHODS

Finally, a total of 4289 individuals aged 50 years or older from wave 2 to wave 8 of the Survey of Health, Ageing and Retirement in Europe were included in this study. The generalized estimated equation model was used to explore the baseline effect of depression with sarcopenia on long-term cognitive function. Stratified Analyses according to gender, education, region, and family economic level were performed. Sensitivity analyses of wave 5 to wave 8 were conducted to ensure the robustness of the results.

RESULTS

Groups of depression with non-sarcopenia (β = -0.40, 95%CI: -0.59 ~ -0.20, P < 0.001), non-depression with sarcopenia (β = -1.11, 95%CI: -1.91 ~ -0.31, P = 0.007), and depression with sarcopenia (β = -1.19, 95%CI: -1.89 ~ -0.50, P = 0.001) were inversely associated with cognition scores compared with the group of non-depression with non-sarcopenia. Stratified Analysis displayed differences in negative association of depression status with sarcopenia status and cognition. Sensitivity analyses yielded similar results. Other than numeracy, depression with sarcopenia (β = -1.81, 95%CI: -2.45 ~ -1.18, P < 0.001; β = -10.68, 95%CI: -1.05 ~ -0.31, P < 0.001; β = -0.51, 95%CI: -0.65 ~ -0.37, P < 0.001; β = -0.41, 95%CI: -0.55 ~ -0.27, P < 0.001) were inversely associated with cognitive function, orientation, words list learning test and fluency.

CONCLUSIONS

Preliminary depressive sarcopenia appears to increase the risk of cognitive decline. There was a downward trend in total cognitive function. The effect of depression combined with sarcopenia on cognitive function may exist in differences in gender, education, region, and family economic level.

Quality of life, household income, and dietary habits are associated with the risk of sarcopenia among the Chinese elderly

BACKGROUND

Health-related quality of life (HRQoL), which can be influenced by various aspects, especially socioeconomic status and lifestyle, has been identified as an important predictor of the prognosis of older adults. Dietary habit, a major part of lifestyle, can affect the nutritional status, which is closely correlated with the development of geriatric syndromes in the elderly.

AIMS

The aim of the study was to examine the association of HRQoL, socioeconomic status, and lifestyle with the risk and severity of sarcopenia, a geriatric syndrome characterized by progressive loss of skeletal muscle mass, strength and function.

METHODS

A cross-sectional retrospective study with 2877 participants aged ≥65 years was performed. HRQoL was assessed using EuroQoL Five Dimensions questionnaire. Socioeconomic status was assessed by the educational attainment, occupation, and household income. Lifestyle was assessed using 12 items closely related to Chinese living habits. The information of daily dietary habits including tea, alcohol, type of diet, and volume of drinking water were collected. The associations of HRQoL, socioeconomic status, and lifestyle with the risk of sarcopenia were examined by multivariate regression logistical analysis. The potential causal role of age, body mass index, and waist circumference in the effect of HRQoL on sarcopenia risk was analyzed by causal mediation analysis.

RESULTS

High HRQoL [adjusted odds ratio (OR) =0.85, 95% confidence interval (CI) =0.69-0.95, P=0.034] and household income levels (adjusted OR =0.74, 95% CI =0.57-0.95, P=0.019) were inversely associated with the risk of sarcopenia. Meanwhile, more consumption of spicy food (adjusted OR =1.34, 95% CI =1.09-1.81, P =0.037) and occasionally drinking (adjusted OR =1.46, 95% CI =1.07-2.00, P =0.016, as compared to those never drinking) were associated with higher risk of sarcopenia, while skipping breakfast occasionally (adjusted OR =0.37, 95% CI =0.21-0.64, P <0.001, as compared to those eating breakfast every day) and less consumption of salt (adjusted OR =0.71, 95% CI =0.52-0.96, P =0.026, as compared to those consuming high amount of salt) were associated with lower risk of sarcopenia. Further causal mediation analysis aimed to explore how much age, body mass index, and waist circumference might explain the effect of HRQoL on the risk of sarcopenia showed that the estimated proportion that mediated the effect of HRQoL on the risk of sarcopenia by age was 28.0%.

CONCLUSIONS

In summary, our findings demonstrate that low levels of HRQoL and household income, more intake of salt and spicy food, and occasional intake of alcohol are correlated with higher risk of sarcopenia, while skipping breakfast occasionally is associated with lower risk of sarcopenia in a Chinese population of older adults.

Genetic evidence of the causal relationship between chronic liver diseases and musculoskeletal disorders

BACKGROUND

Chronic liver diseases constitute a major global public health burden, posing a substantial threat to patients' daily lives and even survival due to the potential development of musculoskeletal disorders. Although the relationship between chronic liver diseases and musculoskeletal disorders has received extensive attention, their causal relationship has not been comprehensively and systematically investigated.

METHODS

This study aimed to assess the causal relationships between viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC), liver cirrhosis, and hepatocellular carcinoma (HCC) with osteoporosis, osteoarthritis, and sarcopenia through bidirectional Mendelian randomization (MR) research. The traits related to osteoporosis and osteoarthritis included both overall and site-specific phenotypes, and the traits linked to sarcopenia involved indicators of muscle mass and function. Random-effect inverse-variance weighted (IVW), weighted median, MR-Egger, and Causal Analysis Using the Summary Effect Estimates were used to evaluate causal effects, with IVW being the main analysis method. To enhance robustness, sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-PRESSO global test, funnel plots, leave-one-out analyses, and latent causal variable model.

RESULTS

The forward MR analysis indicated that PSC can reduce forearm bone mineral density (beta = - 0.0454, 95% CI - 0.0798 to - 0.0110; P = 0.0098) and increase the risk of overall osteoarthritis (OR = 1.012, 95% CI 1.002-1.022; P = 0.0247), while HCC can decrease grip strength (beta = - 0.0053, 95% CI - 0.008 to - 0.0025; P = 0.0002). The reverse MR analysis did not find significant causal effects of musculoskeletal disorders on chronic liver diseases. Additionally, no heterogeneity or pleiotropy was detected.

CONCLUSIONS

These findings corroborate the causal effects of PSC on osteoporosis and osteoarthritis, as well as the causal impact of HCC on sarcopenia. Thus, the implementation of comprehensive preventive measures is imperative for PSC and HCC patients to mitigate the risk of musculoskeletal disorders, ultimately improving their quality of life.

The relationship between lifestyles and sarcopenia-related traits: A two-sample Mendelian randomization study

OBJECTIVE

To investigate the causal association between lifestyles (smoking, drinking consumption and physical activity) and sarcopenia-related traits by Mendelian randomized analysis.

METHODS

Instrumental variables from the genome-wide association study were used for analysis. The exposure factors were lifestyle factors, including smoking, alcohol consumption, moderate physical activity and vigorous physical activity, and the outcome variables were low hand grip strength and appendicular lean mass. The inverse variance weighted (IVW) method and other MR methods were used for analysis. Heterogeneity test, sensitivity analysis and pleiotropy analysis were performed.

RESULTS

According to a primary causal effects model with MR analyses by the IVW method, smoking was a decreased risk of low hand grip strength (odds ratio (OR) = 0.899, 95% confidence interval (CI) = 0.829-0.974, P = 0.010), while alcohol consumption was a significant correlation with low hand grip strength (OR = 1.137, 95% CI = 1.020-1.267, P = 0.020). There was no significant relationship between smoking, alcohol, and appendicular lean mass. In addition, moderate or vigorous physical showed no significant correlation with low hand grip strength and appendicular lean mass.

CONCLUSION

This study demonstrated that smoking may be causally related to a lower risk of low hand grip strength, while alcohol may increase the risk of low hand grip strength. There was no causal relationship between physical activity and sarcopenia-related traits.

Prognostic significance of body mass index in small-cell lung cancer: Exploring the relationship with skeletal muscle status

BACKGROUND

We investigated the prognostic significance of body mass index in small-cell lung cancer and explored whether skeletal muscle status affects the body mass index-survival relationship.

METHODS

This retrospective study evaluated data from patients who underwent platinum-etoposide chemotherapy for small-cell lung cancer between March 2010 and December 2021. Skeletal muscle status was assessed using non-contrast computed tomography images of baseline positron-emission tomography-computed tomography, with the skeletal muscle index defined as the cross-sectional area of skeletal muscle divided by height squared, and the average attenuation values of skeletal muscle. Cox proportional hazards regression analysis was used to determine the correlations of body mass index, skeletal muscle metrics, and overall survival.

RESULTS

We analysed the data of 1146 Asian patients (1006 men and 140 women, with a median age of 67 years [interquartile range: 61-72 years]), including 507 and 639 patients with limited and extensive disease, respectively. Being underweight, defined as a body mass index <18.5 kg/m2 , was associated with shorter overall survival, independent of clinical covariates in both the limited-disease (hazard ratio, 1.77; 95% confidence interval, 1.01-3.09) and extensive-disease (hazard ratio, 1.71; 95% confidence interval, 1.18-2.48) groups. The prognostic value of being underweight remained significant after additional adjustment for skeletal muscle index and attenuation in both limited-disease (hazard ratio, 1.96; 95% confidence interval, 1.09-3.51) and extensive-disease (hazard ratio, 1.75; 95% confidence interval, 1.17-2.61) groups.

CONCLUSIONS

Being underweight is an independent poor prognostic factor for shorter overall survival in Asian patients with small-cell lung cancer, regardless of skeletal muscle status.

Association of telomere length with risk of lung cancer: A large prospective cohort study from the UK Biobank

OBJECTIVES

Leukocyte telomere length (LTL) is associated with a wide variety of diseases, including cancer. However, findings regarding the association between LTL and the risk for lung cancer have been inconclusive and inconsistent across previous observational studies.

METHODS

This prospective cohort study included data from 425,146 participants 37-73 years of age housed in the UK Biobank. Quantitative polymerase chain reaction (qPCR) was used to measure LTL in baseline DNA samples. A multivariate Cox proportional hazards model was used to evaluate the relationship between LTL and the risk for lung cancer.

RESULTS

An increase in LTL per interquartile range (IQR) was associated with a 9% increase in the risk for lung cancer (hazard ratio [HR] 1.09 [95% confidence interval (CI) 1.03-1.16]). Participants in the highest LTL quintile exhibited an approximately 25% elevated risk for developing lung cancer (HR 1.25 [95% CI 1.09-1.45]) compared with those in the lowest quintile. The relationship between per IQR increase in LTL and elevated risk for lung cancer was greater in the histological subtype of adenocarcinoma (HR 1.30 [95% CI 1.18-1.43]), female sex (HR 1.16 [95% CI 1.06-1.26]), non-smokers (HR 1.45 [95% CI 1.23-1.71]), and individuals with high genetic risk for lung cancer (HR 1.18 [95% CI 1.03-1.34]), respectively. Surprisingly, a per IQR increase in LTL was associated with increased risks for both lung adenocarcinoma (HR 1.56 [95% CI 1.24-1.96]) and squamous cell carcinoma (HR 2.01 [95% CI 1.13-3.56]) in never smokers.

CONCLUSIONS

Longer LTL was associated with an elevated risk for lung cancer, particularly for adenocarcinoma and squamous cell carcinoma in never smokers. The results suggest the potential of telomeres as non-invasive biomarkers for the early screening of lung cancer, particularly in non-smokers, who are typically overlooked.

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.