Subclinical inflammation, telomere shortening, homocysteine, vitamin B6, and mortality: the Ludwigshafen Risk and Cardiovascular Health Study.

PURPOSE: Short telomeres and B vitamin deficiencies have been proposed as risk factors for age-related diseases and mortality that interact through oxidative stress and inflammation. However, available data to support this concept are insufficient. We aimed to investigate the predictive role of B vitamins and homocysteine (HCY) for mortality in cardiovascular patients. We explored potential relationships between HCY, B vitamins, relative telomere length (RTL), and indices of inflammation. METHODS: Vitamin B6, HCY, interleukin-6 (IL-6), high-sensitive-C-reactive protein (hs-CRP), and RTL were measured in participants of the Ludwigshafen Risk and Cardiovascular Health Study. Death events were recorded over a median follow-up of 9.9 years. RESULTS: All-cause mortality increased with higher concentrations of HCY and lower vitamin B6. Patients in the 4th quartile of HCY and vitamin B6 had hazard ratios (HR) for all-cause mortality of 2.77 (95% CI 2.28-3.37) and 0.41(95% CI 0.33-0.49), respectively, and for cardiovascular mortality of 2.78 (95% CI 2.29-3.39) and 0.40 (95% CI 0.33-0.49), respectively, compared to those in the 1st quartile. Multiple adjustments for confounders did not change these results. HCY and vitamin B6 correlated with age-corrected RTL (r = - 0.086, p < 0.001; r = 0.04, p = 0.031, respectively), IL-6 (r = 0.148, p < 0.001; r = - 0.249, p < 0.001, respectively), and hs-CRP (r = 0.101, p < 0.001; r = - 0.320, p < 0.001, respectively). Subjects with the longest telomeres had a significantly higher concentration of vitamin B6, but lower concentrations of HCY, IL-6, and hs-CRP. Multiple regression analyses identified HCY as an independent negative predictor of age-corrected RTL. CONCLUSIONS: In conclusion, hyperhomocysteinemia and vitamin B6 deficiency are risk factors for death from any cause. Hyperhomocysteinemia and vitamin B6 deficiency correlate with increased mortality. This correlation might, at least partially, be explained by accelerated telomere shortening induced by oxidative stress and systemic inflammation in these circumstances.

Telomere length, vitamin B12 and mortality in persons undergoing coronary angiography: the Ludwigshafen risk and cardiovascular health study.

BACKGROUND: Vitamin B12 (B12) deficiency and excess are associated with increased risk of age-related-diseases and mortality. It has been suggested that high- and low-B12 concentrations link to increased mortality through accelerated genomic aging and inflammation. Evidence to support this is limited. RESULTS: B12 was associated with all-cause-mortality, RTL and hsCRP in a non-linear fashion. The association between B12 and mortality was not independent, as it lost significance after adjustment for potential confounders. In the lowest-(LB12) and highest-(HB12) quartiles of B12 mortality was higher than in the mid-range (HR:LB12:1.23;CI95%:1.06-1.43; HR:HB12:1.24;CI95%:1.06-1.44). We divided subjects with LB12 in quartiles of their RTL. Those with the longest-telomeres had a lower mortality-rate (HR:0.57;95%CI:0.39-0.83) and lower homocysteine than those with the shortest-telomeres. Amongst subjects with HB12, those with long-telomeres also had a lower mortality than those with short-telomeres (HR:0.40;95%CI:0.27-0.59). IL-6 and hsCRP concentrations were low in HB12LT but were high in HB12ST. METHODS: B12, homocysteine, telomere length (RTL), interleukin-6 (IL-6) and high-sensitive-C-reactive-protein (hsCRP) were measured in 2970 participants of the LURIC study. CONCLUSIONS: Mortality, stratified according to B12 and RTL, seems to be driven by different mechanisms. In LB12 and HB12 subjects, mortality and accelerated telomere shortening might be driven by homocysteine and inflammation, respectively.

ST2 and the ST2/IL-33 signalling pathway-biochemistry and pathophysiology in animal models and humans.

ST2 is an interleukin (IL)-1 receptor family member with transmembrane (ST2L) and soluble (sST2) isoforms. Structurally, the ST2 gene products are very similar in mice and humans. In humans and in mice, alternative promoter activation and splicing produce ST2L and sST2. ST2L represents the longest transcript, whereas sST2 is the truncated, soluble isoform. ST2L is the biological receptor for IL-33, a member of the IL-1 family. IL-33 is the functional ligand of ST2L and signals the presence of tissue damage to local immune cells. IL-33/ST2L signalling leads to the production of inflammatory cytokines/chemokines and to the induction of the immune response. Conversely, sST2 functions as a decoy receptor for IL-33, inhibiting the effects of IL-33/ST2L signalling. Animal studies have allowed the investigation of ST2 and the IL-33/ST2L signalling pathway at multiple levels. However, clinical studies have mainly focused on the determination of sST2 in the circulation. In humans, plasma concentrations of sST2 increase in several diseases, such as heart disease, pulmonary disease, burn injury and graft-versus-host disease. Consequently, increased plasma concentrations of sST2 are not specific for a single disorder in humans and are thus of limited value for diagnostic purposes. However, increased plasma concentrations of sST2 have been linked to a worse prognosis in numerous diseases. Nevertheless, the major source of circulating sST2 in healthy and diseased humans is currently not fully established. In addition, whether the downregulation of sST2 can improve the outcome of patients in the clinical setting has not been elucidated. The aim of the present review was to provide an update on the findings regarding the biochemistry and pathophysiology of ST2 and the sST2 signalling pathway in humans and experimental models.

LC-MS/MS based 25(OH)D status in a large Southern European outpatient cohort: gender- and age-specific differences.

BACKGROUND: Developed countries have a high prevalence of vitamin D deficiency. In previous studies, 25(OH)D was predominantly measured by immunoassays. The present study assessed serum 25(OH)D in a very large Southern European outpatient cohort by liquid chromatography tandem mass spectrometry (LC-MS/MS). MATERIALS AND METHODS: 74,235 serum 25(OH)D results generated under routine conditions between 2015 and 2016 were extracted from the laboratory information system of the Department of Clinical Pathology at Bolzano Hospital (Italy). In 3801 cases, parathyroid hormone (PTH) was requested in parallel. Serum 25(OH)D was measured by a NIST-972 aligned commercial LC-MS/MS method. The distribution of serum 25(OH)D concentrations in males and females of different age groups, the prevalence of 25(OH)D2 and seasonal variability were studied. RESULTS: The average 25(OH)D concentration in the entire cohort was 68.6 nmol/L (7.5-1880 nmol/L). Females had a 7 nmol/L higher average 25(OH)D concentration than males, which increased significantly with age. 37.9 and 28.3% of males and females, respectively, had a deficient 25(OH)D concentration of < 50 nmol/L. 620 samples (0.84%) had measureable amounts of 25(OH)D2. In samples with a normal PTH, 25(OH)D was 11 nmol/L higher than in the entire cohort. Seasonal variation ranged between 20 and 30% and was most pronounced in young individuals. 25(OH)D2 remained constant throughout the year. CONCLUSION: Average serum 25(OH)D in South Tyrol is higher than in other parts of Europe. 25(OH)D and PTH show a continuous inverse relationship. Seasonal variation of serum 25(OH)D is an important aspect in young and middle-aged adults, but becomes less relevant in elderly subjects. 25(OH)D2 is of minor practical importance in South Tyrol.

Telomere length and mortality in the Ludwigshafen Risk and Cardiovascular Health study.

INTRODUCTION: Short telomeres have been associated with adverse lifestyle factors, cardiovascular risk factors and age-related diseases, including cardiovascular disease (CVD), myocardial infarction, atherosclerosis, hypertension, diabetes, and also with mortality. However, previous studies report conflicting results. OBJECTIVES: The aim of the present study has been to investigate the involvement of telomere length in all-cause and CVD mortality in subjects hospitalized for diagnostic coronary angiography of the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. METHODS: Relative telomere length (RTL) was measured with a Q-PCR based method in 3,316 participants of the LURIC study. Age-corrected RTL was calculated as the ratio between RTL and age. Median follow-up was 9.9 years. Cox regression and Kaplan-Maier analyses were performed to evaluate the role of RTL for all-cause and cardiovascular mortality. RESULTS: RTL correlated negatively with age (r = -0.09; p<0.001). In surviving patients the correlation between age and RTL was statistically significant (r = -0.088; p<0.001), but not in patients who died during follow-up (r = -0.043; p = 0.20). Patients in quartiles 2-4 of RTL had a lower hazard ratio for all-cause mortality (HR:0.822; 95%CI 0.712-0.915; p = 0.008) and CVD-mortality (HR:0.836; 95%CI 0.722-0.969; p = 0.017) when compared to those in the 1st quartile. Adjustment for major cardiovascular risk factors did not change this result, however additional adjustment for age attenuated this effect. Patients in the 4th quartile of age-corrected RTL compared to those in the 1st quartile had a lower hazard ratio for all-cause mortality, even with adjustment for major cardiovascular risk factors. CONCLUSIONS: The present study supports the hypothesis that short telomere length increases the risk of all-cause and CVD mortality. Age appears to be an important co-variate that explains a substantial fraction of this effect. It remains unclear whether short telomeres contribute directly to the increase in mortality or if they are simply a surrogate marker for other adverse processes of aging.

Telomere biology and age-related diseases.

Telomeres are the protective end caps of chromosomes and shorten with every cell division. Telomere length has been proposed as a biomarker of biological age and a risk factor for age-related diseases. Epidemiologic studies show an association between leukocyte telomere length (LTL) and mortality. There is solid evidence that links LTL with cardiovascular disease. Short telomeres promote atherosclerosis and impair the repair of vascular lesions. Alzheimer's disease patients have also a reduced LTL. Telomeres measured in tumor tissue from breast, colon and prostate are shorter than in healthy tissue from the same organ and the same patient. In healthy tissue directly adjacent to these tumors, telomeres are also shorter than in cells that are more distant from the cancerous lesion. A reduced telomere length in cancer tissue from breast, colon and prostate is associated with an advanced disease state at diagnosis, faster disease progression and poorer survival. By contrast, results regarding LTL and cancer are inconsistent. Furthermore, the majority of studies did not find significant associations between LTL, bone mineral density (BMD) and osteoporosis. The present manuscript gives an overview about our current understanding of telomere biology and reviews existing knowledge regarding the relationship between telomere length and age-related diseases.

Observational retrospective study of vascular modulator changes during treatment in essential thrombocythemia.

Essential thrombocythemia (ET) patients are at risk of developing thrombotic events. Qualitative platelet (PLT) abnormalities and activation of endothelial cells (ECs) and PLTs are thought to be involved. Microparticles (MPs) can originate from PLTs (PMPs), ECs (EMPs), or red cells (RMPs). Previous studies have indicated that MPs contribute to ET pathophysiology. Endothelial modulators (eg, nitric oxide [NO], adrenomedullin [ADM], and endothelin-1 [ET-1]) are also involved in the pathophysiology of this condition. We hypothesized that treatments for reducing PLT count might also indirectly affect MP generation and endothelial activity by altering endothelial modulator production. The rationale of this study was that hydroxyurea (HU), a cytostatic drug largely used in ET, induces the production of a potent vasoactive agent NO in ECs. An observational retrospective study was designed to investigate the relationship between MPs, NO, ADM, and ET-1 in ET patients on treatment with HU, anagrelide (ANA), aspirin (ASA), and a group of patients before treatment. A total of 63 patients with ET diagnosis: 18 on HU + ASA, 15 on ANA + ASA, 19 on ASA only, and 11 untreated patients, and 18 healthy controls were included in this study. Blood samples were analyzed for MP (absolute total values) and functional markers (percentage values) by flow cytometry. PLT-derived MPs were studied using CD61, CD62P, CD36, and CD63, whereas endothelial-derived MPs were studied using CD105, CD62E, and CD144. Endothelial modulator markers (NO, ADM, and ET-1) were measured by ELISA. Total MP count was higher in the group treated with ANA + ASA (P < 0.01). MP markers modified in ET patients returned to levels of healthy controls following treatment, in particular, in patients on ANA treatment. NO and ADM values were higher in the HU group (P < 0.001). HU and ANA treatment also affected MP production in a cell origin-specific manner. HU and ANA, although acting via different pathways, have similar final effects. For instance, HU causes vasodilatation by increasing NO and ADM levels, whereas ANA impairs vasoconstriction by reducing ET-1. In conclusion, therapy with HU cytostatic drugs and ANA can reduce PLT count in ET, and also affect endothelial modulatory agents, with HU sustaining vasodilation and prothrombotic MP concentration, whereas ANA decreases vasoconstriction.

Assessment of vitamin D status - a changing landscape.

In recent years it has been shown that vitamin D deficiency is associated with an increased incidence as well as the progression of a broad range of diseases including osteoporosis, rickets, cardiovascular disease, autoimmune disease, multiple sclerosis and cancer. Consequently, requests for the assessment of vitamin D status have increased dramatically. Despite significant progress in the analysis of vitamin D metabolites and an expansion of our pathophysiological knowledge of vitamin D, the assessment of vitamin D status remains a challenging and partially unresolved issue. Current guidelines from scientific bodies recommend the measurement of 25-hydroxy vitamin D (25-OHD) in blood as the preferred test. However, growing evidence indicates significant limitations of this test, including analytical aspects and interpretation of results. In addition, the relationships between 25-OHD and various clinical indices, such as bone mineral density and fracture risk, are rather weak and not consistent across races. Recent studies have systematically investigated new markers of vitamin D status including the vitamin D metabolite ratio (VMR) (ratio between 25-OHD and 24,25-dihydroxy vitamin D), bioavailable 25-OHD [25-OHD not bound to vitamin D binding protein (DBP)], and free 25-OHD [circulating 25-OHD bound to neither DBP nor albumin (ALB)]. These parameters may potentially change how we will assess vitamin D status in the future. Although these new biomarkers have expanded our knowledge about vitamin D metabolism, a range of unresolved issues regarding their measurement and the interpretation of results prevent their use in daily practice. It can be expected that some of these issues will be overcome in the near future so that they may be considered for routine use (at least in specialized centers). In addition, genetic studies have revealed several polymorphisms in key proteins of vitamin D metabolism that affect the circulating concentrations of vitamin D metabolites. The affected proteins include DBP, 7-dehydrocholesterol synthase and the vitamin D receptor (VDR). Here we aim to review existing knowledge regarding the biochemistry, physiology and measurement of vitamin D. We will also provide an overview of current and emerging biomarkers for the assessment of vitamin D status, with particular attention methodological aspects and their usefulness in clinical practice.

One-carbon metabolites and telomere length in a prospective and randomized study of B- and/or D-vitamin supplementation.

BACKGROUND: Vitamin B deficiency is common in elderly people and has been associated with an increased risk of developing age-related diseases. B-vitamins are essential for the synthesis and stability of DNA. Telomers are the end caps of chromosomes that shorten progressively with age, and short telomers are associated with DNA instability. OBJECTIVE: In the present randomized intervention study, we investigated whether the one-carbon metabolism is related to telomere length, a surrogate marker for cellular aging. DESIGN: Sixty-five subjects (>54 years) were randomly assigned to receive either a daily combination of vitamin D3 (1200 IU), folic acid (0.5 mg), vitamin B12 (0.5 mg), vitamin B6 (50 mg) and calcium carbonate (456 mg) (group A) or vitamin D3 and calcium carbonate alone (group B). Blood testing was performed at baseline and after 1 year of supplementation. The concentrations of several metabolites of the one-carbon pathway, as well as relative telomere length (RTL) and 5,10-methylenetetrahydrofolate reductase C677T genotype, were analyzed. RESULTS: At baseline, age- and gender-adjusted RTL correlated with total folate and 5-methyltetrahydrofolate (5-methylTHF). Subjects with RTL above the median had higher concentrations of total folate and 5-methylTHF compared to subjects below the median. At study end, gender- and age-adjusted RTL correlated in group A with methylmalonic acid (MMA; r = -0.460, p = 0.0012) and choline (r = 0.434, p = 0.0021) and in group B with 5,10-methenyltetrahydrofolate (r = 0.455, p = 0.026) and dimethylglycine (DMG; r = -0.386, p = 0.047). Subjects in the group A with RTL above the median had lower MMA and higher choline compared to subjects below the median. CONCLUSIONS: The present pilot study suggests a functional relationship between one-carbon metabolism and telomere length. This conclusion is supported by several correlations that were modified by B-vitamin supplementation. In agreement with our hypothesis, the availability of nucleotides and methylation groups seems to impact telomere length. Due to the small sample size and the limitations of the study, further studies should confirm the present results in a larger cohort.