Association Between Weight Change and Leukocyte Telomere Length in U.S. Adults

Associations of weight-adjusted-waist index and systemic immune-inflammatory index with sKlotho: evidence from the NHANES 2007-2016

Background

Klotho is an anti-aging protein, and obesity and inflammation have been identified as having a relationship with Klotho. This study investigated the correlation between weight-adjusted-waist index(WWI), systemic inflammation index(SII) and soluble Klotho (sKlotho) and explored the potential mediating role of SII.

Methods

The association between WWI, SII, and sKlotho was investigated using weighted multivariate linear regression, subgroup analysis, and smoothed curve fitting in this cross-sectional study, which was based on NHANES data. The Bootstrap method was used to test for mediation effects. Covariate selection was validated using the variance inflation factor (VIF).

Results

The study involved a total of 9,506 participants. The results showed that WWI (β=-0.03; 95%CI:-0.04,-0.01; p<0.0001) was associated with SII (β=-0.00, 95%CI:-0.00,-0.00:p<0.001) and Ln-sKlotho.There was a negative correlation between both WWI and SII and sKlotho. Subgroup analysis showed that gender, age, education, marital status, family income, HEI, PA, hypertension, diabetes, CKD, alcohol use, smoking, and SII did not affect the negative correlation between WWI and sKlotho (FDR-corrected p>0.1). The mediation analysis showed that SII played a significant mediating effect in the role of WWI on sKlotho, with SII mediating 6.78% of the relationship between WWI and sKlotho.

Conclusion

There is a negative correlation between WWI and sKlotho, and SII may be an important mediator between WWI and sKlotho. Reducing inflammatory conditions in obese populations may increase sKlotho levels, which in turn may delay organismal aging in middle-aged and elderly people.

The multi-omics signatures of telomere length in childhood

BACKGROUND

Telomere length is an important indicator of biological age and a complex multi-factor trait. To date, the telomere interactome for comprehending the high-dimensional biological aspects linked to telomere regulation during childhood remains unexplored. Here we describe the multi-omics signatures associated with childhood telomere length.

METHODS

This study included 1001 children aged 6 to 11 years from the Human Early-life Exposome (HELIX) project. Telomere length was quantified via qPCR in peripheral blood of the children. Blood DNA methylation, gene expression, miRNA expression, plasma proteins and serum and urinary metabolites were measured through microarrays or (semi-) targeted assays. The association between each individual omics feature and telomere length was assessed in omics-wide association analyses. In addition, a literature-guided, sparse supervised integration method was applied to multiple omics, and latent components were extracted as predictors of child telomere length. The association of these latent components with early-life aging risk factors (child lifestyle, body mass index (BMI), exposure to smoking, etc.), were interrogated.

RESULTS

After multiple-testing correction, only two CpGs (cg23686403 and cg16238918 at PARD6G gene) out of all the omics features were significantly associated with child telomere length. The supervised multi-omics integration approach revealed robust associations between latent components and child BMI, with metabolites and proteins emerging as the primary contributing features. In these latent components, the contributing molecular features were known as involved in metabolism and immune regulation-related pathways.

CONCLUSIONS

Findings of this multi-omics study suggested an intricate interplay between telomere length, metabolism and immune responses, providing valuable insights into the molecular underpinnings of the early-life biological aging.

Associations of Depression Score with Dialkyl Phosphate Metabolites in Urine: A Cross-Sectional Study

OBJECTIVES

Growing evidence suggests a link between organophosphate insecticides and depression disorder. These chemicals are metabolized and subsequently expelled through the urinary tract. The present study aims to investigate whether dialkyl phosphate metabolites associate with depression score and severity among the general population.

METHODS

This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES). Depression was evaluated by the Patient Health Questionnaire-9 (PHQ-9). All urinary dialkyl phosphate metabolites were quantitatively analyzed. The survey's complex design parameters and sampling weights were considered.

RESULTS

3035 eligible individuals were included. The estimated prevalence of mild and major depression was 18.3% (95% confidence interval [CI]: 16.9-19.7%) and 9.9% (95% CI: 8.7-11.0%). For each incremental unit in the level of urinary dimethyl phosphate (DMP), individuals were found to have a higher depression score of 0.77 and a significantly increased odds ratio (OR) of 1.13 (95% CI: 1.12-1.13) for mild depression and 2.75 (95% CI: 2.74-2.76) for major depression.

CONCLUSIONS

Our findings indicate positive and independent associations between urinary dialkyl phosphate metabolites and an elevated risk of depression among the general population.

Increased magnesium intake does not mitigate MAFLD risk associated with magnesium deficiency

Serum magnesium cannot accurately assess magnesium deficiency. The association between magnesium deficiency and metabolic dysfunction-associated fatty liver disease (MAFLD) remains unclear. Selecting 3,377 participants in the United States, we assessed the degree of magnesium deficiency in the population using magnesium depletion score (MDS). Multinomial logistic regression assessed the association between magnesium deficiency and MAFLD. Subgroup analyses assessed the association between dietary magnesium intake and MAFLD under different magnesium deficiency statuses. Structural equation modeling (SEM) revealed mediation effects. Magnesium deficiency was associated with MAFLD (ORseverevs.none: 1.69, 95%CI: 1.16-2.46; p for trend < 0.001). Magnesium intake was negatively associated with MAFLD only in the subgroup without magnesium deficiency (p for trend < 0.01). Inflammation, oxidative stress, and aging significantly mediated the association between MDS and MAFLD (all p < 0.05). In American adults, magnesium deficiency assessed by MDS might be a risk factor for MAFLD, with inflammation, oxidative stress, and aging potentially being key mechanisms. Simply increasing magnesium intake would not mitigate MAFLD risk associated with magnesium deficiency. Correcting magnesium deficiency might prevent MAFLD.

Associations of childhood and adulthood body size, and child-to-adult body size change with adult telomere length

AIM

To comprehensively examine the associations of childhood and adulthood body size, and child-to-adult body size change with adult leucocyte telomere length (LTL).

METHODS

We included 453 602 participants from the UK Biobank. Childhood body size at the age of 10 years was collected through a questionnaire. Adulthood body size was assessed using body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), fat mass index (FMI), and fat-free mass index (FFMI).

RESULTS

Individuals with plumper body size in childhood exhibited shorter LTL in adulthood (-0.0086 [-0.0017, -0.0004]). Adulthood BMI (-0.0286 [-0.0315, -0.0258]), WC (-0.0271 [-0.0303, -0.0238]), WHR (-0.0269 [-0.0308, -0.0230]) and FMI (-0.0396 [-0.0438, -0.0351]) were negatively associated with LTL, whereas FFMI (0.0095 [0.0039, 0.0152]) was positively associated with LTL. Compared to individuals consistently having an average/normal weight in both childhood and adulthood, those who maintained or developed overweight/obesity from childhood to adulthood had a shorter adult LTL, regardless of childhood body size. Notably, the LTL shortening effect was not observed in individuals with plumper body size in childhood but normal weight in adulthood.

CONCLUSIONS

Childhood and adulthood obesity are both associated with LTL shortening in adulthood. Transitioning to or maintaining overweight/obese status from childhood to adulthood is associated with shorter adult LTL, whereas this effect can be reversed if plumper children become normal weight.

Association between weight change and serum anti-aging protein α-Klotho: a cross-sectional study in middle-aged and older adults

The relationship of weight change has extended to accelerated ageing, yet little is known about the association between weight change and anti-aging protein α-Klotho. This study included 10,972 subjects from the National Health and Nutrition Examination Survey 2007-2016. Participants were measured body weight and height at baseline and recalled weight at young adulthood and middle adulthood. α-Klotho concentrations were quantified. Generalized linear regression models were used to assess the association between weight change and α-Klotho. Across adulthood, maximal overweight, non-obese to obese, and stable obesity were consistently associated with lower serum Klotho levels. Compared with participants who remained at normal weight, from middle to late adulthood, participants experiencing maximal overweight, moving from the non-obese to obese, and maintaining obesity had 27.97 (95% CI: - 46.57 to - 9.36), 39.16 (95% CI: - 61.15 to - 17.18), and 34.55 (95% CI: - 55.73 to - 13.37) pg/ml lower α-Klotho, respectively; similarly, from young to late adulthood, those had 29.21 (95% CI: - 47.00 to - 11.42) , 34.14 (95% CI: - 52.88 to - 15.40), and 36.61 (95% CI: - 65.01 to - 8.21) lower, respectively. Interestingly, from middle to late adulthood, the absolute weight change values of 590 participants who changed from obese to non-obese were negatively associated with serum α-Klotho. Each 1 kg of weight loss during the process of changing from obese to non-obese brought about a relative increase in α-Klotho levels of 3.03 pg/ml. The findings suggest the potential role of weight management across adulthood for aging.

Body mass index mediates the association between four dietary indices and phenotypic age acceleration in adults: a cross-sectional study

Background: Diet and body mass index (BMI) are widely recognized as being closely associated with aging. However, it remains unclear which dietary indices are associated with aging, and the extent to which BMI mediates the relationship between diet and aging. Therefore, this study investigates the mediating role of BMI in the association between various dietary indices and phenotypic age acceleration (PhenoAgeAccel). Methods: Data were sourced from the National Health and Nutrition Examination Survey (NHANES), using two 24 hour recall interviews to compute four dietary indices: the Dietary Inflammatory Index (DII), Healthy Eating Index-2020 (HEI-2020), Alternative Healthy Eating Index-2010 (AHEI-2010), and Composite Dietary Antioxidant Index (CDAI). Linear regression analyses and mediation analyses assessed the associations between dietary indices and PhenoAgeAccel and the mediating effects of BMI. Z-score transformations (zDII, zHEI-2020, zAHEI-2010, and zCDAI) were used to ensure comparability between different dietary indices. Results: After adjusting for covariates, the zHEI-2020, zAHEI-2010, and zCDAI were negatively associated with PhenoAgeAccel (P < 0.05), with β values being -0.36, -0.40, and -0.41, respectively. The zDII was positively associated with PhenoAgeAccel (P < 0.001) with a β value of 0.70. Mediation analyses suggested that BMI significantly mediated the relationships between these dietary indices and PhenoAgeAccel. The mediation proportions were 23.7% for zDII, 43.3% for zHEI-2020, 24.5% for zAHEI-2010, and 23.6% for zCDAI. Conclusions: This study indicates that all dietary indices and BMI were significantly associated with PhenoAgeAccel. In addition, BMI exhibited the highest mediation proportion in the relationship between HEI-2020 and PhenoAgeAccel.

Involvement of Inheritance in Determining Telomere Length beyond Environmental and Lifestyle Factors

All linear chromosomal ends have specific DNA-protein complexes called telomeres. Telomeres serve as a "molecular clock" to estimate the potential length of cell replication. Shortening of telomere length (TL) is associated with cellular senescence, aging, and various age-related diseases in humans. Here we reviewed the structure, function, and regulation of telomeres and the age-related diseases associated with telomere attrition. Among the various determinants of TL, we highlight the connection between TL and heredity to provide a new overview of genetic determinants for TL. Studies across multiple species have shown that maternal and paternal TL influence the TL of their offspring, and this may affect life span and their susceptibility to age-related diseases. Hence, we reviewed the linkage between TL and parental influences and the proposed mechanisms involved. More in-depth studies on the genetic mechanism for TL attrition are needed due to the potential application of this knowledge in human medicine to prevent premature frailty at its earliest stage, as well as promote health and longevity.

Are pregnancy and parity associated with telomere length? A systematic review

BACKGROUND

Women's reproduction requires increased energy demands, which consequently may lead to cellular damage and aging. Hence, Telomere Length (TL), a biomarker of biological aging and health status may possibly serve as a biomarker of reproductive effort. The aim of this systematic review is to evaluate telomere dynamics throughout pregnancy and the association between parity and TL.

METHODS

A systematic search was conducted across seven databases including CINAHL, Cochrane, PsycINFO, Proquest, PubMed; Scopus; and Web of Science, using keywords and MeSH descriptors of parity and TL. Predefined inclusion and exclusion criteria were used to screen abstracts and titles. After the removal of duplicates, 3431 articles were included in the primary screening, narrowed to 194 articles included in the full-text screening. Consensus was reached for the 14 studies that were included in the final review, and the Newcastle-Ottawa scale (NOS) was utilized to assess the quality of the selected studies. A mini meta-analysis utilized JASP 0.17.3 software and included 4 applicable studies, comprising a total of 2564 participants to quantitatively assess the estimated effect size of parity on TL.

RESULTS

Of the 11 studies reviewed on parity and TL, four demonstrated a negative correlation; one - a positive correlation and six -found no correlation. Studies demonstrating a negative correlation encompassed rigorous methodological practices possibly suggesting having more children is associated with enhanced telomere attrition. Of the four longitudinal studies assessing telomere dynamics throughout pregnancy, most found no change in TL from early pregnancy to postpartum suggesting pregnancy does not affect TL from early pregnancy to early postpartum. The meta-analysis revealed a negative, yet, non-significant effect, of the estimated effect size of parity on TL(ES = -0.009, p = 0.126, CI -0.021, 0.03).

CONCLUSIONS

Studies assessing pregnancy, parity and TL yielded mixed results, most likely due to the different research methods utilized in each study. Improvements in study design to better understand the short-term effects of pregnancy on TL and the effect of parity on TL over time, include precise definitions of parity, comparisons of different age groups, inclusion of reproductive lifespan and statistically adjusting for potential confounders in the parity and TL relationship.

Causal relationships between telomere length and liver disease: a Mendelian randomization study

Background: Leukocyte telomere length and hepatic disorders have been linked in various research studies, although their causative association has not been clarified. This study investigated the causal relationship between the length of telomeres on peripheral blood leukocytes and certain liver disorders. Methods: Mendelian randomization (MR) analysis was used to examine the relationship between leukocyte telomere length and risk of liver disease using the publicly accessible worldwide gene-wide association study (GWAS) database. The weighted mode, weighted median, and inverse variance weighted (IVW) methods were employed as supplements to the IVW approach, which is the main analytical method. Results: Leukocytes with longer telomeres may have a lower risk of developing cirrhosis [OR = 0.645 (0.524, 0.795), p = 3.977E-05] and a higher chance of developing benign liver tumors [OR = 3.087 (1.721, 5.539), p = 1.567E-04]. There was no direct link between telomere length and fatty liver, hepatic fibrosis, or liver cancer. Our findings in the replication analysis agreed with those of the previous studies. Conclusion: Further research is needed to examine the mechanisms underlying the probable causal association between the length of leukocyte telomeres and cirrhosis and benign liver cancer.

Weight Change over Ten Years Predicts Biological Aging in a Random Sample of 3070 U.S. Adults

This investigation was designed to study the relationship between weight change over 10 years and leukocyte telomere length (LTL) in a large sample of 3070 randomly selected U.S. adults, 36-70 years old. The National Health and Nutrition Examination Survey (NHANES) data were used to examine the relationship between percent weight change and LTL. Potential mediating variables were controlled using partial correlation. After adjusting for age, race, year, and housing status, the association between percent weight change over 10 years and LTL was significant in women (F = 6.9, p = 0.0138). Adjusting for the demographic and several other covariates weakened the relationship slightly (F = 4.7, p = 0.0392). With all the covariates controlled, for each one percentage point increase in weight over the previous 10 years, telomeres were, on average, 3.48 base pairs (bp) shorter in women. Given that each one-year increase in age was associated with telomeres that were 15.0 bp shorter in women, the median weight change in U.S. women over the previous 10 years (an increase of 10.4%) was predictive of LTLs that were 36 bp shorter, on average, or an increase of 2.4 years of biological aging. Percent weight change over 10 years was not associated with LTL in U.S. men. Percent weight change over 10 years is a strong predictor of biological aging in U.S. women, but not in men.

Telomere length dynamics measured by flow-FISH in patients with obesity undergoing bariatric surgery

Obesity has negative effects on comorbidities, health-related quality of life and survival. Telomere length (TL) changes after bariatric surgery have been reported, but the studies are contradictory, and analyses using state-of-the art techniques for TL measurement, such as flow-FISH, are sparse. We measured TL dynamics via flow-FISH in patients undergoing bariatric surgery and compared their TL with 105 healthy individuals. Patients with obesity who underwent bariatric surgery were included. Lymphocyte and granulocyte absolute and age-adjusted (aa) TL were analyzed by flow-FISH before (preoperative cohort, n = 45) and after surgery (follow-up cohort, n = 35) at month 5.5 ± 3.9 (mean ± standard deviation [SD]). The initial lymphocyte aaTL was significantly shorter (-0.37 kb ± 0.18 kb, P = 0.045) in patients with obesity, while the granulocyte aaTL was not different from that in the healthy comparison population (0.28 kb ± 0.17 kb, P = 0.11). The telomere dynamics after surgery showed an increase in mean TL in both lymphocytes and granulocytes of patients with a pronounced BMI loss of ≥ 10 kg/m². We did not find any association between TL increase after surgery and age, sex or the type of procedure selected for bariatric surgery. We confirmed that patients suffering from obesity have significantly shorter lymphocyte TL using flow-FISH. Along with and dependent on the degree of weight reduction after bariatric surgery, TL significantly increased in both lymphocytes and granulocytes after a mean of 5.5 months. Our results show that bariatric surgery affects not only body weight but also biomarkers of aging, such as TL.

Identifying effects of genetic obesity exposure on leukocyte telomere length using Mendelian randomization

Background

Observational studies have shown that obesity is closely associated with leukocyte telomere length (LTL). However, the causal relationship between obesity and LTL remains unclear. This study investigated the causal relationship between obesity and LTL through the Mendelian randomization approach.

Materials and Methods

The genome-wide association study (GWAS) summary data of several studies on obesity-related traits with a sample size of more than 600,000 individuals were extracted from the UK Biobank cohort. The summary-level data of LTL-related GWAS (45 6,717 individuals) was obtained from the IEU Open GWAS database. An inverse-variance-weighted (IVW) algorithm was utilized as the primary MR analysis method. Sensitivity analyses were conducted via MR-Egger regression, IVW regression, leave-one-out test, MR-pleiotropy residual sum, and outlier methods.

Results

High body mass index was correlated with a short LTL, and the odds ratio (OR) was 0.957 (95% confidence interval [CI] 0.942-0.973, p = 1.17E-07). The six body fat indexes (whole body fat mass, right leg fat mass, left leg fat mass, right arm fat mass, left arm fat mass, and trunk fat mass) were consistently inversely associated with LTL. Multiple statistical sensitive analysis approaches showed that the adverse effect of obesity on LTL was steady and dependable.

Conclusion

The current study provided robust evidence supporting the causal assumption that genetically caused obesity is negatively associated with LTL. The findings may facilitate the formulation of persistent strategies for maintaining LTL.

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.

Potential effect of dietary zinc intake on telomere length: A cross-sectional study of US adults

BACKGROUND

Telomere length, which is related to chronic diseases and premature mortality, is influenced by dietary factors. Zinc is known as a dietary antioxidant micronutrient, however, its impact on telomere length remains unclear.

OBJECTIVE

We aimed to examine the potential effect of dietary zinc intake on telomere length among middle-aged and older individuals in the US.

MATERIALS AND METHODS

Our study included 3,793 US participants aged 45 years and older from the 1999 to 2002 National Health and Nutrition Examination Survey (NHANES). 24-h dietary recall interviews were employed to evaluate zinc consumption. Leukocyte telomere length was assessed by real-time quantitative polymerase chain reaction (qPCR). We adopted generalized linear models to investigate the effect of dietary zinc intake on telomere length, and subgroup analyses were further applied. We further evaluated the dose-response relationship using restricted cubic spline analysis.

RESULTS

Among the 3,793 participants, the average telomere length was 0.926 ± 0.205 (T/S ratio) or 5509.5 ± 494.9 (bp). After adjusting for major confounders, every 5 mg increment in dietary zinc consumption was related to 0.64% (95% CI: 0.17%, 1.10%) longer telomere length. In the subgroup analyses, significant relationships were found in females (Percentage change: 1.11%; 95% CI: 0.48%, 1.75%), obese (Percentage change: 0.88%; 95% CI: 0.26%, 1.50%), and low energy intake individuals (Percentage change: 0.99%; 95% CI: 0.51%, 1.46%). Additionally, we revealed a positive linear relationship between dietary zinc intake and telomere length (P for non-linearity = 0.636).

CONCLUSION

Our study revealed that elevated dietary zinc intake was significantly related to longer telomere length among adults aged 45 years and older in the US. And the association was more pronounced in females, obese, and low energy intake individuals.

Telomere Length and Mitochondrial DNA Copy Number Variations in Patients with Obesity: Effect of Diet-Induced Weight Loss-A Pilot Study

Background: Telomere length (TL) and mitochondrial DNA (mtDNA) copy number shifts are linked to metabolic abnormalities, and possible modifications by diet-induced weight loss are poorly explored. We investigated the variations before (T0) and after a 1-year (T12) lifestyle intervention (diet + physical activity) in a group of outpatients with obesity. Methods: Patients aged 25−70 years with BMI ≥ 30 kg/m2 were enrolled. Clinical and biochemical assessments (including a blood sample for TL, mtDNA copy number and total antioxidant capacity, and TAC determinations) were performed at T0 and T12. Results: The change in TL and the mtDNA copy number was heterogeneous and not significantly different at T12. Patients were then divided by baseline TL values into lower than median TL (L-TL) and higher than median TL (H-TL) groups. The two groups did not differ at baseline for anthropometric, clinical, and laboratory characteristics. At T12, the L-TL group when compared to H-TL showed TL elongation (respectively, +0.57 ± 1.23 vs. −2.15 ± 1.13 kbp, p = 0.04), higher mtDNA copy number (+111.5 ± 478.5 vs. −2314.8 ± 724.2, respectively, p < 0.001), greater weight loss (−8.1 ± 2.7 vs. −6.1 ± 4.6 Kg, respectively, p = 0.03), fat mass reduction (−1.42 ± 1.3 vs. −1.22 ± 1.5%, respectively, p = 0.04), and increased fat-free mass (+57.8 ± 6.5 vs. +54.9 ± 5.3%, respectively, p = 0.04) and TAC levels (+58.5 ± 18.6 vs. +36.4 ± 24.1 µM/L, respectively, p = 0.04). Conclusions: TL and the mtDNA copy number significantly increased in patients with obesity and with lower baseline TL values after a 1-year lifestyle intervention. Larger longitudinal studies are needed to confirm the results of this pilot study.