Relationship between plasma 25-hydroxyvitamin D and leucocyte telomere length by sex and race in a US study

Very Low and High Levels of Vitamin D Are Associated with Shorter Leukocyte Telomere Length in 148,321 UK Biobank Participants

Background: Shorter leukocyte telomere length (LTL) is observed in multiple age-related diseases, which are also associated with vitamin D deficiency (i.e., osteosarcopenia, neurocognitive disorders, cancer, osteoarthritis, etc.), suggesting a close association between vitamin D and LTL. In this study, we examined the relationship between vitamin D levels and LTL in older participants of the UK Biobank. Methods: Data were collected from the UK Biobank. Participants aged 60 and older (n = 148,321) were included. Baseline LTL was measured using a multiplex qPCR technique and expressed as the ratio of the telomere amplification product (T) to that of a single-copy gene (S) (T/S ratio). Serum 25-hydroxyvitamin D (25OHD) was stratified by z score and linked to LTL in a linear regression model adjusting for covariates. Results: Compared to the medium level, a low (in the range of 16.6 nmol/L, 29.7 nmol/L) or extremely low (≤16.6 nmol/L) level of serum 25OHD was associated with shorter LTL: 0.018 SD (standardized β = −0.018, 95% CI −0.033 to −0.003, p = 0.022) and 0.048 SD (standardized β = −0.048, 95% CI −0.083 to −0.014, p = 0.006), respectively. Additionally, the high serum 25OHD groups (>95.9 nmol/L) had 0.038 SD (standardized β = −0.038, 95% CI −0.072 to −0.004, p = 0.030) shorter mean LTL than the group with medium 25OHD levels. The associations above were adjusted for multiple variables. Conclusions: In this population-based study, we identified an inverted U-shape relationship between LTL and vitamin D status. Our findings could be affected by unmeasured confounders. Whether high or low vitamin D-associated shorter LTL is mechanistically related to age-related conditions remains to be elucidated.

A Multivitamin Mixture Protects against Oxidative Stress-Mediated Telomere Shortening

Telomeres are nucleotide repeat sequences located at the end of chromosomes that protect them from degradation and maintain chromosomal stability. Telomeres shorten with each cell division; hence telomere length is associated with aging and longevity. Numerous lifestyle factors have been identified that impact the rate of telomere shortening; high vitamin consumption has been associated with longer telomere length, whereas oxidative stress is associated with telomere shortening. In this paper, we sought to determine if a multivitamin mixture containing both vitamins and a blend of polyphenolic compounds, could reduce telomere shortening consequent to an oxidative stress (10 uM H2O2 for 8 weeks) in a primary fibroblast cell culture model. Under conditions of oxidative stress, the median and 20th percentile telomere length were significantly greater (p < 0.05), and the percentage of critically short telomeres (<3000 bp) was significantly less (p < 0.05) in cells treated with the multivitamin mixture at 4, 15 and 60 ug/ml compared to control (0 ug/ml). Median and 20th percentile telomere shortening rate was also reduced under the same conditions (p < 0.05). Taken together, these findings demonstrate that the multivitamin mixture protects against oxidative stress-mediated telomere shortening in cell culture, findings which may have implications in human health.

Effects of Vitamin D Supplementation on Telomere Length: An Analysis of Data from the Randomised Controlled D-Health Trial

OBJECTIVES

Observational studies have suggested that a higher 25-hydroxyvitamin D concentration may be associated with longer telomere length; however, this has not been investigated in randomised controlled trials. We conducted an ancillary study within a randomised, double-blind, placebo-controlled trial of monthly vitamin D (the D-Health Trial) for the prevention of all-cause mortality, conducted from 2014 to 2020, to assess the effect of vitamin D supplementation on telomere length (measured as the telomere to single copy gene (T/S) ratio).

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

Participants were Australians aged 60-84 years and we randomly selected 1,519 D-Health participants (vitamin D: n=744; placebo: n=775) for this analysis. We used quantitative polymerase chain reaction to measure the relative telomere length (T/S ratio) at 4 or 5 years after randomisation. We compared the mean T/S ratio between the vitamin D and placebo groups to assess the effect of vitamin D supplementation on relative telomere length, using a linear regression model with adjustment for age, sex, and state which were used to stratify the randomisation.

RESULTS

The mean T/S ratio was 0.70 for both groups (standard deviation 0.18 and 0.16 for the vitamin D and placebo groups respectively). The adjusted mean difference (vitamin D minus placebo) was -0.001 (95% CI -0.02 to 0.02). There was no effect modification by age, sex, body mass index, or predicted baseline 25-hydroxyvitamin D concentration.

CONCLUSION

In conclusion, routinely supplementing older adults, who are largely vitamin D replete, with monthly doses of vitamin D is unlikely to influence telomere length.

Associations between Vitamin D, Omega 6:Omega 3 Ratio, and Biomarkers of Aging in Individuals Living with and without Chronic Pain

Elevated inflammatory cytokines and chronic pain are associated with shorter leukocyte telomere length (LTL), a measure of cellular aging. Micronutrients, such as 25-hydroxyvitamin D (vitamin D) and omega 3, have anti-inflammatory properties. Little is known regarding the relationships between vitamin D, omega 6:3 ratio, LTL, inflammation, and chronic pain. We investigate associations between vitamin D, omega 6:3 ratio, LTL, and C-reactive protein (CRP) in people living with/without chronic pain overall and stratified by chronic pain status. A cross-sectional analysis of 402 individuals (63% women, 79.5% with chronic pain) was completed. Demographic and health information was collected. Chronic pain was assessed as pain experienced for at least three months. LTL was measured in genomic DNA isolated from blood leukocytes, and micronutrients and CRP were measured in serum samples. Data were analyzed with general linear regression. Although an association between the continuous micronutrients and LTL was not observed, a positive association between omega 6:3 ratio and CRP was detected. In individuals with chronic pain, based on clinical categories, significant associations between vitamin D, omega 6:3 ratio, and CRP were observed. Findings highlight the complex relationships between anti-inflammatory micronutrients, inflammation, cellular aging, and chronic pain.

Association of Telomere Length and Serum Vitamin D Levels with Type 2 Diabetes Mellitus and its Related Complications: A Possible Future Perspective

Evidence show that shortened telomere length (TL) and low Vitamin D levels can increase the risk of type 2 diabetes mellitus (T2DM) and its associated complications. T2DM has been considered as an age-related disease, it may be associated with TL. The study aimed to evaluate the association of TL and Vitamin D levels with complications of T2DM and the impact of Vitamin D on TL in patients with T2DM. This 1-year cross-sectional study was conducted at a tertiary care hospital on 90 patients. Height, weight, body mass index, waist-hip ratio was calculated. Fasting blood sugars, postprandial blood sugar, and glycated hemoglobin (HbA1c) were analyzed. Absolute TL was obtained from quantitative real-time polymerase chain reaction (qPCR). Vitamin D estimation was done by chemiluminescent immunoassay. Descriptive analysis of the data was done using R i386 3.6.3. The study found a positive correlation between TL and Vitamin D levels (r = 0.64; P < 0.0001). The interaction with high HbA1c levels and lower levels of Vitamin D led to the shortening of TL (P = 0.0001). The median of TL and mean of Vitamin D levels were significantly less in the diabetic group (P < 0.0001). Vitamin D levels positively affected the TL and its levels had an inverse relation with the HbA1c levels. This association had a significant effect on the shortening of TL. Vitamin D also had a significant association with other diabetic complications that instigated the shortening of TL. Therefore, assessing the role of Vitamin D levels on the shortening of TL can prove to be crucial biomarkers in managing optimal glycemic levels in T2DM patients.

The Association between 25-Hydroxyvitamin D Concentration and Telomere Length in the Very-Old: The Newcastle 85+ Study

(1) Introduction: vitamin D may maintain the telomere length, either directly or via the inflammation effect and/or modulating the rate of cell proliferation. Whilst results from cross-sectional studies investigating the association between 25(OH)D concentration and telomere length have been mixed, there is a dearth of data from prospective studies which have assessed these associations. This study aimed to examine the association between 25(OH)D concentration in plasma and telomere length in blood cells in very-old adults (≥85 years old) at baseline, 18 months and 36 months by controlling for related lifestyle factors. (2) Methodology: our prospective cohort study comprised 775 participants from the Newcastle 85+ Study who had 25(OH)D measurements at baseline. Plasma 25(OH)D was stratified as <25 nmol/L (low), 25-50 nmol/L (moderate) and >50 nmol/L (high). Peripheral blood mononuclear cell telomere length was measured by quantitative real-time polymerase chain reaction at baseline, 18 and 36 months from baseline. (3) Results: a positive significant association was found between 25(OH)D concentration and telomere length amongst very-old participants at baseline (95% CI = 12.0-110.3, B = 61.2 ± 5.0, p = 0.015). This association was negative at 18 months (95% CI = -59.9--7.5, B = -33.7 ± 13.3, p = 0.012) but was non-significant at 36 months. (4) Conclusion: Circulating 25(OH)D concentration shows inconsistent relationships with telomere length over time in very-old (85+ year old) adults.

Vitamin D Deficiency and Risk of Metabolic Syndrome in Aging Men

The elderly population is rapidly increasing; hence, the disability due to age-related diseases has become an important socioeconomic burden. Amongst age-related diseases cardiovascular ones (CVD) have a huge impact on morbidity and mortality and are associated with metabolic syndrome (MetS). Several studies investigated the role of hypovitaminosis D in the pathogenesis of MetS and of CVD, this review unravels the relationship between aging/senescence, vitamin D, gender, and pathogenesis of MetS.

Epigenetic Clock and Leukocyte Telomere Length Are Associated with Vitamin D Status but not with Functional Assessments and Frailty in the Berlin Aging Study II

DNA methylation (DNAm) age acceleration, a parameter derived via the epigenetic clock, has recently been suggested as a biomarker of aging. We hypothesized that accelerated biological aging, measured by both this new and the established biomarker of aging, relative leukocyte telomere length (rLTL), are associated with vitamin D deficiency. Moreover, we tested for an association between rLTL/DNAm age acceleration and different clinical assessments for functional capacity, including the Fried frailty score. Cross-sectional data of 1,649 participants of the Berlin Aging Study II was available (~50% female, age: 22-37 and 60-84 years). A seven cytosine-phosphate-guanine clock was estimated to calculate the DNAm age acceleration. rLTL was measured by quantitative real-time polymerase chain reaction (PCR). 25-hydroxyvitamin D (25(OH)D) serum levels <25 nmol/L was defined as vitamin D deficiency and <50 nmol/L as vitamin D insufficiency. Vitamin D-sufficient individuals had a 1.4 years lower mean DNAm age acceleration (p < .05, analysis of variance [ANOVA]) and a 0.11 longer rLTL (p < .001, ANOVA) than vitamin D-deficient participants. Likewise, vitamin D-sufficient participants had lower DNAm age acceleration (β = 1.060, p = .001) and longer rLTL (β = -0.070; p < .001) than vitamin D nonsufficient subjects in covariate-adjusted analysis. Neither DNAm age acceleration nor rLTL were significantly associated with the Fried frailty score or the functional assessments. Only the clock drawing test was associated with DNAm age acceleration (subgroup of older men: β = 1.898, p = .002). Whether the analyzed biomarkers of aging can be used to predict an individual's functional capacity or will be associated with frailty in the advanced course of aging, will be clarified by future longitudinal analyses.

Impact of Nutrition on Telomere Health: Systematic Review of Observational Cohort Studies and Randomized Clinical Trials

Diet, physical activity, and other lifestyle factors have been implicated in the pathophysiology of several chronic diseases, but also in a lower total mortality and longer life expectancy. One of the mechanisms in which diet can reduce the risk of disease is with regard to its impact on telomeres. Telomere length (TL) is highly correlated to chronological age and metabolic status. Individuals with shorter telomeres are at higher risk of chronic diseases and mortality. Diet may influence TL by several mechanisms such as regulating oxidative stress and inflammation or modulating epigenetic reactions. The present systematic review aims to examine the results from epidemiologic and clinical trials conducted in humans evaluating the role of nutrients, food groups, and dietary patterns on TL. We also discuss the possible mechanisms of action that influence this process, with the perspective that TL could be a novel biomarker indicating the risk of metabolic disturbances and age-related diseases. The available evidence suggests that some antioxidant nutrients, the consumption of fruits and vegetables, and Mediterranean diet are mainly associated with longer telomeres. However, most of the evidence is based on high heterogenic observational studies and very few randomized clinical trials (RCTs). Therefore, the associations summarized in the present review need to be confirmed with larger prospective cohort studies and better-designed RCTs.

Impact of serum 25-hydroxyvitamin D 25(OH) on telomere attrition: A Mendelian Randomization study

BACKGROUND

Conventional observational studies have suggested that 25-hydroxyvitamin D (25(OH)D) is inversely associated with telomere shortening. We aimed to apply two-sample Mendelian randomization (MR) to assess the causal association between serum 25(OH) D and telomere length (TL).

METHODS

MR was implemented by using summary-level data from the largest genome-wide association studies (GWAS) on vitamin D (n = 73 699) and TL (n = 37 684). Inverse variance weighted method (IVW) was used to estimate the causal estimates. Weighted median (WM)-based method, and MR-Egger, leave-one-out were applied as sensitivity analysis.

RESULTS

The results of MR demonstrated no effect of 25(OH)D on TL (IVW = β:-0.104, p = 0.219, WM = β:-0.109, p = 0.188; MR Egger = β:-0.127, p = 0.506). None of the 25(OH)D-related single nucleotide polymorphisms (SNPs) were significantly associated with TL. Heterogeneity tests did not detect heterogeneity. Furthermore, MR pleiotropy residual sum and outlier (MR-PRESSO) did not highlight any outliers (p = 0.424). Results of leave-one-out method demonstrated that the links are not driven because of the single SNPs.

CONCLUSIONS

Our study does not support any causal effect of 25(OH) D on TL.

Inflammatory disease and C-reactive protein in relation to therapeutic ionising radiation exposure in the US Radiologic Technologists

Chronic inflammation underlies many autoimmune diseases, including hypothyroidism, hyperthyroidism, and rheumatoid arthritis, also type-2 diabetes and osteoarthritis. Associations have been suggested of high-dose ionising radiation exposure with type-2 diabetes and elevated levels of C-reactive protein, a marker of chronic inflammation. In this analysis we used a proportional hazards model to assess effects of radiotherapy on risks of subsequent inflammatory disease morbidity in 110,368 US radiologic technologists followed from a baseline survey (1983–1989/1994–1998) through 2008. We used a linear model to assess log-transformed C-reactive protein concentration following radiotherapy in 1326 technologists. Relative risk of diabetes increased following radiotherapy (p < 0.001), and there was a borderline significant increasing trend per treatment (p = 0.092). For osteoarthritis there was increased relative risk associated with prior radiotherapy on all questionnaires (p = 0.005), and a significant increasing trend per previous treatment (p = 0.024). No consistent increases were observed for other types of inflammatory disease (hypothyroidism, hyperthyroidism, rheumatoid arthritis) associated with radiotherapy. There was a borderline significant (p = 0.059) increasing trend with dose for C-reactive protein with numbers of prior radiotherapy treatments. Our results suggest that radiotherapy is associated with subsequent increased risk of certain inflammatory conditions, which is reinforced by our finding of elevated levels of C-reactive protein.

Serum 25-Hydroxyvitamin D Has a Modest Positive Association with Leukocyte Telomere Length in Middle-Aged US Adults

Background: Vitamin D deficiency has been linked to all-cause mortality and cancer. However, the biological plausibility of these associations is not well established. Leukocyte telomere length (LTL) shortening is associated with aging and is a hallmark of genomic instability and carcinogenesis.Objective: We aimed to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and LTL in the general US population.Methods: We analyzed data from the US NHANES 2001-2002. The study population comprised 1542 younger adults (aged 20-39 y), 1336 middle-aged adults (aged 40-59 y), and 1382 older adults (aged ≥60 y). LTL was measured by using quantitative polymerase chain reaction. Serum 25(OH)D concentrations ≥50 nmol/L were considered optimal. Linear regression, adjusted for age, sex, race/ethnicity, body mass index (BMI), total energy and sugar intakes, calcium intake, socioeconomic status, milk and dietary supplement consumption, and physical activity, was applied to investigate the association between serum 25(OH)D and LTL.Results: In the total population, age, sex, BMI, and non-Hispanic black race/ethnicity were significant predictors of LTL. In the participants aged 40-59 y, an increment in serum 25(OH)D of 10 nmol/L was associated with a 0.03- ± 0.01-kbp longer LTL, adjusted for age, sex, race/ethnicity, and other factors (P = 0.001). In the same age group, 25(OH)D concentrations ≥50 nmol/L were associated with a 0.13- ± 0.04-kbp longer LTL than those for 25(OH)D concentrations <50 nmol/L (P = 0.01). The association was independent of age, sex, race/ethnicity, BMI, and other factors.Conclusions: In a nationally representative population of adults, serum 25(OH)D was positively associated with LTL in middle-aged participants (aged 40-59 y), independently of other factors. These findings suggest that decreased 25(OH)D concentrations are associated with genomic instability, although the clinical impact of this observation remains unclear.

The association of telomere length and serum 25-hydroxyvitamin D levels in US adults: the National Health and Nutrition Examination Survey

INTRODUCTION

Higher vitamin D levels and longer telomere length (TL) have been associated with lower risk of several chronic diseases and all-cause mortality. However, direct relationships between 25-hydroxyvitamin D (25(OH)D) levels and TL are not well established. Vitamin D could influence TL through its anti-inflammatory properties. This study aimed to assess the relationship between vitamin D levels and TL in US adults.

MATERIAL AND METHODS

Participants of the National Health and Nutrition Examination Survey (NHANES) with data available on 25(OH)D and TL measures from 2001 to 2002 were included. 25(OH)D levels were measured by the DiaSorin Radioimmunoassay. We used multivariable-adjusted linear regression models, accounting for the survey design and sample weights.

RESULTS

Of the 4347 eligible participants, 47.0% (n = 2045) were men. The mean age was 42.7 years overall, 49.2 years in men and 42.5 years in women (p = 0.060). After adjustment for age, race, marital status, education, and C-reactive protein, each 1 ng/ml higher 25(OH)D level was associated with a 0.045 (95% confidence interval (CI): 0.032 to 0.059) longer telomere-to-single copy gene (T/S) ratio. This was driven by a significant association in women (0.054 (0.043 to 0.064)) and in men (0.036 (0.020 to 0.052)). However, after we further adjusted for smoking, body mass index, and physical activity, no significant relation was found in the overall sample (β coefficient -0.026, 95% CI: -3.16, 1.67), for men (-0.016 (-3.72, 2.64)), or for women (-0.052 (-6.85, 2.26)).

CONCLUSIONS

Our findings support a possible positive association between 25(OH)D levels and telomere length. The implications of this association deserve further investigation.