Association between serum ferritin and hypertension according to the working type in Korean men: the fifth Korean National Health and nutrition examination survey 2010-2012

Associations Between Genetically Predicted Iron Status and Cardiovascular Disease Risk: A Mendelian Randomization Study

BACKGROUND

Mendelian randomization (MR) studies suggest a causal effect of iron status on cardiovascular disease (CVD) risk, but it is unknown if these associations are confounded by pleiotropic effects of the instrumental variables on CVD risk factors. We aimed to investigate the effect of iron status on CVD risk controlling for CVD risk factors.

METHODS AND RESULTS

Iron biomarker instrumental variables (total iron-binding capacity [n=208 422], transferrin saturation [n=198 516], serum iron [n=236 612], ferritin [n=257 953]) were selected from a European genome-wide association study meta-analysis. We performed 2-sample univariate MR of each iron trait on CVD outcomes (all-cause ischemic stroke, cardioembolic ischemic stroke, large-artery ischemic stroke, small-vessel ischemic stroke, and coronary heart disease) from MEGASTROKE (n=440 328) and CARDIoGRAMplusC4D (Coronary Artery Disease Genome Wide Replication and Meta-Analysis Plus the Coronary Artery Disease Genetics) (n=183 305). We then implemented multivariate MR conditioning on 7 CVD risk factors from independent European samples to evaluate their potential confounding or mediating effects on the observed iron-CVD associations. With univariate MR analyses, we found higher genetically predicted iron status to be associated with a greater risk of cardioembolic ischemic stroke (transferrin saturation: odds ratio, 1.17 [95% CI, 1.03-1.33]; serum iron: odds ratio, 1.21 [95% CI, 1.02-1.44]; total iron-binding capacity: odds ratio, 0.81 [95% CI, 0.69-0.94]). The detrimental effects of iron status on cardioembolic ischemic stroke risk remained unaffected when adjusting for CVD risk factors (all P<0.05). Additionally, we found diastolic blood pressure to mediate between 7.1 and 8.8% of the total effect of iron status on cardioembolic ischemic stroke incidence. Univariate MR initially suggested a protective effect of iron status on large-artery stroke and coronary heart disease, but controlling for CVD factors using multivariate MR substantially diminished these associations (all P>0.05).

CONCLUSIONS

Higher iron status was associated with a greater risk of cardioembolic ischemic stroke independent of CVD risk factors, and this effect was partly mediated by diastolic blood pressure. These findings support a role of iron status as a modifiable risk factor for cardioembolic ischemic stroke.

Higher serum ferritins are associated with higher blood pressure: A cross-sectional study

The aim of the study was to investigate the association between serum ferritin and hypertension among American adults from National Health and Nutrition Examination Survey (NHANES) 1999 to 2018. A total of 16,125 participants were included. Weighted logistic regression and subgroup analyses were performed to explore the association. We found that serum ferritin was closely correlated to hypertension. Individuals with high serum ferritin were more likely to have higher systolic or diastolic blood pressure (SBP, DBP) than those with lower serum ferritin. Restricted cubic spline showed a significant non-linear association between serum ferritin and SBP/DBP. Higher level of serum ferritin (Q3 74.1-147 μg/L and Q4 > 147 μg/L) was found to have positive association with high SBP [Q3 (OR: 1.246, 95% CI:1.020-1.523), Q4 (OR: 1.354, 95% CI:1.096-1.674)], and hypertension [Q3 (OR: 1.283, 95% CI:1.099-1.499), Q4 (OR: 1.424, 95% CI:1.197-1.63)] in the whole population. In people aged between 20 and 60, subjects with high serum ferritin were significantly associated with a higher risk of hypertension, but in those over 60, the relationship between serum ferritin level and hypertension is negative. A non-linear association between serum ferritin and SBP, as well as DBP, was discovered. There was age difference in association between serum ferritin and hypertension in American adults, and further researches were needed to understand the mechanisms behind the difference.

Associations between genetically predicted iron status and cardiovascular disease risk: A Mendelian randomization study

Background

Mendelian randomization (MR) studies suggest a causal effect of iron (Fe) status on cardiovascular disease (CVD) risk, but it is unknown if these associations are confounded by pleiotropic effects of the instrumental variables (IV) on CVD risk factors. We aimed to investigate the effect of Fe status on CVD risk controlling for CVD risk factors.

Methods

Fe biomarker IVs (total Fe binding capacity (TIBC, n=208,422), transferrin saturation (TSAT, n=198,516), serum Fe (SI, n=236,612), ferritin (n=257,953)) were selected from a European GWAS meta-analysis. We performed two-sample univariate (UV) MR of each Fe trait on CVD outcomes (all-cause ischemic stroke (IS), cardioembolic IS (CES), large artery IS (LAS), small vessel IS (SVS), and coronary heart disease (CHD)) from MEGASTROKE (n=440,328) and CARDIoGRAMplusC4D (n=183,305). We then implemented multivariate (MV) MR conditioning on six CVD risk factors from independent European samples to evaluate their potential confounding and/or mediating effects on the observed Fe-CVD associations.

Results

With UVMR analyses, we found higher genetically predicted Fe status to be associated with a greater risk of CES (TSAT: OR 1.17 [95%CI 1.03, 1.33], SI: OR 1.21 [ 95%CI 1.02, 1.44]; TIBC: OR 0.81 [95%CI 0.69, 0.94]). The detrimental effects of Fe status on CES risk remained unaffected when adjusting for CVD risk factors (all P<0.05). Additionally, we found diastolic blood pressure (DBP) to mediate between 7.1-8.8% of the total effect of Fe status on CES incidence. While UVMR initially suggested a protective effect of Fe status on LAS and CHD, MVMR analyses factoring CVD risk factors revealed a complete annulment of this perceived protective effect (all P>0.05).

Discussion

Higher Fe status was associated with a greater risk of CES independent of CVD risk factors, and this effect was partly mediated by DBP. These findings support a role of Fe status as a modifiable risk factor for CES.

Dietary intakes of total, nonheme, and heme iron and hypertension risk: a longitudinal study from the China Health and Nutrition Survey

AIMS

Evidence is limited regarding the long-term impact of dietary iron intake on the development of hypertension. We investigated the association between dietary intakes of total, nonheme, and heme iron and hypertension risk in a large prospective cohort of Chinese populations over 26 years.

METHODS

A total of 16,122 adults (7810 men and 8312 women) who participated in the China Health and Nutrition Survey (1989-2015) were included. Dietary intake was repeatedly assessed by combining three consecutive 24‑h individual dietary recalls with household food inventory weighing at each survey round. Incident hypertension was defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg, diagnosis by physicians, or current use of anti-hypertensive drugs.

RESULTS

During a median follow‑up of 11.1 years, 2863 men and 2532 women developed hypertension. After adjustment for non-dietary and dietary factors, a lower risk of hypertension was found in men and women with higher intakes of total, nonheme, or heme iron. The adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the highest vs. lowest quartiles were 0.76 (0.67, 0.87) in men and 0.85 (0.74, 0.97) in women for total iron intake, 0.77 (0.67, 0.87) in men and 0.85 (0.74, 0.98) in women for nonheme iron intake, and 0.73 (0.62, 0.87) in men and 0.69 (0.58, 0.82) in women for heme iron intake. Dose-response analyses further revealed a U-shaped association of total and nonheme iron intake and an L-shaped association of heme iron intake with hypertension risk in both men and women (all P for non-linearity < 0.001).

CONCLUSIONS

Our findings emphasize the importance of maintaining moderate iron intake in the prevention of hypertension. Both insufficient and excess intake of iron might increase the risk of hypertension.

The associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents: a prospective cohort study

Uncontrolled pediatric hypertension may increase the risk of hypertension in adulthood. Several studies have reported an association between hematological parameters and blood pressure (BP) levels. However, epidemiologic evidence of this association in children and adolescents remains scarce. This study aims to explore the associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents. This longitudinal study was conducted with 1368 participants aged 6-8 years from baseline visit to follow-up visit. Compared with participants from the normal blood pressure (BP) group, participants from the elevated BP group had significantly higher baseline red blood cell (RBC) counts, hemoglobin (Hb) counts and hematocrit (Hct) levels (all P < 0.001). A multilevel linear mixed model was conducted to analyze the relationship between hematological parameters and BP levels. The results suggested that SBP, DBP and MAP increased significantly with a quartile increase of levels of hematological parameters (all P < 0.05). Furthermore, a multilevel mixed logistic regression model was used to analyze the risk of per interquartile range increase in hematological parameters on the incidence of prehypertension and hypertension. The risk of prehypertension and hypertension incidence increased by (1.34 (95%CIs: 1.20, 1.50)), (1.38 (95%CIs: 1.24,1.54)), (1.33 (95%CIs: 1.19,1.50)), (1.14 (95%CIs: 1.03,1.26)) fold with a one-quartile increase in levels of RBC, Hb, Hct and Fe, respectively (all P < 0.05). This longitudinal study showed that hematological parameters were positively associated with BP levels in healthy children and adolescents, which excluded the effect of antihypertensive drugs on BP levels that often appeared in adults.

Is iron status associated with markers of non-communicable disease in adolescent Indian children?

BACKGROUND

High body iron status has been associated with non-communicable diseases (NCD) like diabetes (high fasting blood glucose, FBG), hypertension (HTN) or dyslipidaemia (high total cholesterol, TC) in adults, but this has not been examined in adolescent children. This is relevant to iron supplementation and food iron fortification programs that are directed at Indian children.

METHODS

The association of NCD with Serum Ferritin (SF) was examined using logistic additive models, adjusted for confounders such as age, body mass index, C-Reactive Protein, haemoglobin and sex, in adolescent (10-19 years old) participants of the Indian Comprehensive National Nutrition Survey. The interaction of these associations with wealth and co-existing prediabetes was also examined. A scenario analysis was also done to understand the impact of iron fortification of cereals on the prevalence NCD among adolescents.

RESULTS

The odds ratio (OR) of high FBG, HTN and TC were 1.05 (95% CI: 1.01-1.08), 1.02 (95% CI: 1.001-1.03) and 1.04 (95% CI: 1.01-1.06) respectively for every 10 µg/L increase in SF. The odds for high TC increased with co-existing prediabetes. The scenario analysis showed that providing 10 mg of iron/day by fortification could increase the prevalence of high FBG by 2-14% across states of India. Similar increments in HTN and TC can also be expected.

CONCLUSIONS

High SF is significantly associated with NCD in adolescents, dependent on wealth and co-existing prediabetes. This should be considered when enhancing iron intake in anaemia prevention programs, and the NCD relationship with body iron stores should be studied.

Association between soluble transferrin receptor and systolic hypertension in adults: National Health and Nutrition Examination Survey (2007–2010 and 2015–2018)

Background

Hypertension increases the global burden of disease and mortality. Iron metabolism is considered to be an important factor in hypertension. However, as an indicator of iron metabolism, little is known about the associations of soluble transferrin receptor (sTfR) with hypertension. We studied the relationship between sTfR and hypertension.

Materials and methods

We studied 7,416 adults aged 20 years old or above from the National Health and Nutrition Examination Survey (NHANES), a nationally representative, cross-sectional, population-based study. Weighted logistic regression was used to examine the association between markers of iron metabolism and hypertension. The restricted cubic spline (RCS) was used to characterize the association between sTfR and blood pressure.

Results

Weighted logistic regression showed that higher sTfR level was associated with higher odds of hypertension (OR = 1.05; 95% CI: 1.01–1.05; p = 0.001) after adjustment for all the potential confounding factors. Meanwhile, weighted logistic regression analyses indicated independent associations of high sTfR (p = 0.009) with systolic hypertension after adjusting for various different confounders. The result of restricted cubic splines showed a non-linear association between sTfR and systolic blood pressure among U.S. adults.

Conclusion

Soluble transferrin receptor was found to be an independent factor in systolic hypertension. And, a non-linear relationship between sTfR and systolic blood pressure was discovered.

A proposed method for defining the required fortification level of micronutrients in foods: An example using iron

In 2006, the WHO published a framework for calculating the desired level of fortification of any micronutrient in any staple food vehicle, to reduce micronutrient malnutrition. This framework set the target median nutrient intake, of the population consuming the fortified food, at the 97.5th percentile of their nutrient requirement distribution; the Probability of Inadequacy (PIA) of the nutrient would then be 2.5%. We argue here that the targeted median nutrient intake should be at Estimated Average Requirement (50^th percentile), since the intake distribution will then overlap the requirement distribution in a population that is in homeostasis, resulting in a PIA of 50%. It is also important to recognize that setting the target PIA at 2.5% may put a sizable proportion at risk of adverse consequences associated with exceeding the tolerable upper limit (TUL) of intake. This is a critical departure from the WHO framework. For a population with different age- and sex-groups, the pragmatic way to fix the fortification level for a staple food vehicle is by achieving a target PIA of 50% in the most deprived age- or sex-group of that population, subject to the condition that only a very small proportion of intakes exceed the TUL. The methods described here will aid precision in public health nutrition, to pragmatically determine the precise fortification level of a nutrient in a food vehicle, while balancing risks of inadequacy and excess intake.

Role of Iron-Related Oxidative Stress and Mitochondrial Dysfunction in Cardiovascular Diseases

Iron is indispensable in numerous biologic processes, but abnormal iron regulation and accumulation is related to pathological processes in cardiovascular diseases. However, the underlying mechanisms still need to be further explored. Iron plays a key role in metal-catalyzed oxidative reactions that generate reactive oxygen species (ROS), which can cause oxidative stress. As the center for oxygen and iron utilization, mitochondria are vulnerable to damage from iron-induced oxidative stress and participate in processes involved in iron-related damage in cardiovascular disease, although the mechanism remains unclear. In this review, the pathological roles of iron-related oxidative stress in cardiovascular diseases are summarized, and the potential effects and mechanisms of mitochondrial iron homeostasis and dysfunction in these diseases are especially highlighted.

Appraising the Causal Association between Systemic Iron Status and Heart Failure Risk: A Mendelian Randomisation Study

Although observational studies have shown that abnormal systemic iron status is associated with an increased risk of heart failure (HF), it remains unclear whether this relationship represents true causality. We aimed to explore the causal relationship between iron status and HF risk. Two-sample Mendelian randomisation (MR) was applied to obtain a causal estimate. Genetic summary statistical data for the associations (p < 5 × 10−8) between single nucleotide polymorphisms (SNPs) and four iron status parameters were obtained from the Genetics of Iron Status Consortium in genome-wide association studies involving 48,972 subjects. Statistical data on the association of SNPs with HF were extracted from the UK biobank consortium (including 1088 HF cases and 360,106 controls). The results were further tested using MR based on the Bayesian model averaging (MR-BMA) and multivariate MR (MVMR). Of the twelve SNPs considered to be valid instrumental variables, three SNPs (rs1800562, rs855791, and rs1799945) were associated with all four iron biomarkers. Genetically predicted iron status biomarkers were not causally associated with HF risk (all p > 0.05). Sensitivity analysis did not show evidence of potential heterogeneity and horizontal pleiotropy. Convincing evidence to support a causal relationship between iron status and HF risk was not found. The strong relationship between abnormal iron status and HF risk may be explained by an indirect mechanism.

The association between serum ferritin and blood pressure in adult women: a large cross-sectional study

BACKGROUND

Studies on the relationships between ferritin and blood pressure remain limited, especially in adult women. The aim of the present study was to investigate the associations between serum ferritin and blood pressure among adult women.

METHODS

Using the National Health and Nutrition Examination Survey, a cross-sectional study, including 5521 adult women, was performed. Weighted multivariate regressions, subgroup analyses, threshold effect analyses, and sensitivity analysis were used.

RESULTS

The authors found that serum ferritin was independently and positively correlated to diastolic blood pressure (DBP), and this positive correlation kept present among women who are 26-30 years old, non-pregnant women, Mexican American women, and women of other races in the subgroup analyses. Additionally, no significant association was found between serum ferritin and systolic blood pressure (SBP), except in women aged 26-30, Mexican American women, and women of other races. In pregnant women, the association between serum ferritin and SBP was an inverted U-shaped curve with an inflection point at 39.5 ng/mL.

CONCLUSIONS

The authors demonstrated that serum ferritin was positively correlated to DBP in adult women, which may provide a novel reference for clinical management.

Influence of serum ferritin combined with blood cadmium concentrations on blood pressure and hypertension: From the Korean National Health and Nutrition Examination Survey

BACKGROUND

Previous studies have suggested that cadmium (Cd) exposure and serum ferritin levels may influence the development of hypertension.

OBJECTIVE

We evaluated whether the association between blood Cd levels and the development of hypertension could be modified by serum ferritin levels in a representative sample of the adult population of South Korea.

METHODS

We used data from the Korean National Health and Nutrition Examination Survey (2008-2012), a nationally representative, cross-sectional, population-based study. We included 5752 adults aged 19 years and older who had records of blood Cd and ferritin levels and blood pressure measurements. Multiple logistic regression was used to examine the association between Cd exposure and the development of hypertension, as well as the modifying effects of serum ferritin.

RESULTS

Men had higher levels of serum ferritin, and women had higher levels of Cd. Smoking in men was significantly associated with high blood pressure and risk of hypertension. Significantly fewer women were smokers, and the combination of abnormal serum ferritin levels and high Cd levels was significantly associated with high systolic blood pressure [odds ratio (OR) = 2.11; 95% confidence interval (CI) = 1.04-4.28], high diastolic blood pressure (OR = 2.07; 95% CI = 1.04-4.12), and increased hypertension risk (OR = 1.83; 95% CI = 1.03-3.25) in women who never smoked.

CONCLUSIONS

Our results provide further evidence that individuals with abnormal serum ferritin levels should limit their exposure to Cd to prevent hypertension.

Iron in Cardiovascular Disease: Challenges and Potentials

Iron is essential for many biological processes. Inadequate or excess amount of body iron can result in various pathological consequences. The pathological roles of iron in cardiovascular disease (CVD) have been intensively studied for decades. Convincing data demonstrated a detrimental effect of iron deficiency in patients with heart failure and pulmonary arterial hypertension, but it remains unclear for the pathological roles of iron in other cardiovascular diseases. Meanwhile, ferroptosis is an iron-dependent cell death that is distinct from apoptosis, necroptosis, and other types of cell death. Ferroptosis has been reported in several CVDs, namely, cardiomyopathy, atherosclerotic cardiovascular disease, and myocardial ischemia/reperfusion injury. Iron chelation therapy seems to be an available strategy to ameliorate iron overload-related disorders. It is still a challenge to accurately clarify the pathological roles of iron in CVD and search for effective medical intervention. In this review, we aim to summarize the pathological roles of iron in CVD, and especially highlight the potential mechanism of ferroptosis in these diseases.

Quantitative susceptibility mapping to evaluate brain iron deposition and its correlation with physiological parameters in hypertensive patients

Background

Regional excessive iron overload is pernicious to motor functions and cognitive functioning of the brain. The aim of this research was to utilize quantitative susceptibility mapping (QSM) to inspect brain iron accumulation in patients with hypertension (HP), and to evaluate whether it is correlated with physiological parameters.

Methods

Thirty-one HP and 31 age- and sex-matched healthy controls (HC) were included. All participants underwent brain magnetic resonance imaging (MRI), and QSM data were obtained. Differences in brain iron deposition in deep gray matter nuclei of participants were compared between HP and HC. The correlations between iron deposition, body mass index (BMI), maximum systolic blood pressure (SBP), and diastolic blood pressure (DBP) were analyzed.

Results

The HP group showed increased susceptibility values in the caudate nucleus (CA), putamen (PU), globus pallidus (GP), and dorsal thalamus (TH), compared with the HC group. There was a significant positive correlation between BMI and the susceptibility values in the dentate nucleus (DN); the maximum SBP and DBP were positively correlated with magnetic susceptibility of the CA, PU, GP, and TH, respectively.

Conclusions

These results are indicative of the role of overload brain iron in deep brain gray matter nuclei in HP and suggest that HP is associated with excess brain iron in certain deep gray matter regions.

Maternal Iron Status in Early Pregnancy and Blood Pressure Throughout Pregnancy, Placental Hemodynamics, and the Risk of Gestational Hypertensive Disorders

BACKGROUND

In nonpregnant populations, higher serum ferritin, which reflects high iron stores, is associated with an increased risk of hypertension. We hypothesized that a dysregulated maternal iron status in early pregnancy may lead to impaired gestational hemodynamic adaptations, leading to an increased risk of gestational hypertensive disorders.

OBJECTIVES

We examined the associations of maternal iron status with maternal blood pressure, placental hemodynamic parameters, and the risks of gestational hypertensive disorders.

METHODS

In a population-based prospective cohort study among 5983 pregnant women, we measured maternal serum ferritin, transferrin saturation, serum iron, and transferrin concentrations at a median of 13.2 weeks gestation (95% range, 9.6-17.6). Maternal blood pressure was measured in early pregnancy, mid pregnancy, and late pregnancy, and placental hemodynamic parameters in mid pregnancy and late pregnancy were measured by ultrasound. Information on gestational hypertensive disorders was collected from medical records. We examined the associations of maternal early pregnancy iron status with maternal systolic and diastolic blood pressure, placental hemodynamic parameters, and the risks of gestational hypertensive disorders using linear and logistic regression models.

RESULTS

Higher maternal early pregnancy serum ferritin concentrations were associated with higher systolic and diastolic blood pressure throughout pregnancy in the basic models (P values < 0.05). After adjustment for maternal inflammation, sociodemographic and lifestyle factors, higher maternal early pregnancy serum ferritin concentrations were only associated with a higher early pregnancy diastolic blood pressure [0.27 (95% CI, 0.03-0.51) mmHg per SD score increase in serum ferritin] and with a higher mid pregnancy umbilical artery pulsatility index (P < 0.05). No associations with the risk of gestational hypertensive disorders were present.

CONCLUSIONS

No consistent associations were present of maternal iron status in early pregnancy with gestational hemodynamic adaptations or the risks of gestational hypertensive disorders. Further studies are needed to examine the potential role of iron metabolism in the development of gestational hypertensive disorders within higher-risk populations.

Hematological abnormalities and comorbidities are associated with COVID-19 severity among hospitalized patients: Experience from Bangladesh

BACKGROUND

The hematological abnormalities are assumed to be involved in the disease progression of COVID-19. However, the actual associations between specific blood parameters and COVID-19 are not well understood. Here we aimed to assess the correlations between hematological parameters and the severity of COVID-19.

METHODS

We included COVID-19 patients who were admitted to Evercare Hospital Ltd, Dhaka, Bangladesh, between November 10, 2020, to April 12, 2021, with a confirmed case of RT-PCR test. We recorded demographic information, clinical data, and routine hematological examination results of all COVID-19 patients. We performed statistical analyses and interpretation of data to compare severe COVID-19 patients (SCP) and non-severe COVID-19 patients (NSCP).

RESULTS

The age and BMI of the admitted COVID-19 patients were 48.79±8.53 years and 25.82±3.75 kg/m2. This study included a total of 306 hospitalized COVID-19 patients. Among them, NSCP and SCP were 198 and 108, respectively. And we recorded 12 deaths from SCP. We observed the alterations of several hematological parameters between SCP and NSCP. Among them, we noticed the increased levels of C-reactive protein (CRP), d-dimer, and ferritin showed good indicative value to evaluate the severity of COVID-19. Also, there were positive correlations among these parameters. Moreover, we found correlations between the outcomes of COVID-19 patients with patient's demographics and comorbid diseases.

CONCLUSION

Based on our results, CRP, d-dimer, and ferritin levels at admission to hospitals represent simple assessment factors for COVID-19 severity and the treatment decisions at the hospital setup. These blood parameters could serve as indicators for the prognosis and severity of COVID-19. Therefore, our study findings might help to develop a treatment protocol for COVID-19 patients at the hospital setup.

Telomere Length and Oxidative Stress and Its Relation with Metabolic Syndrome Components in the Aging

Simple Summary

A link between telomere length and some age-related diseases has been identified, including metabolic syndrome. So far, there is no mechanism to explain the origin or cause of telomere shortening in this syndrome; however, oxidative stress is a constant factor. Therefore, we reviewed scientific evidence that supported the association between oxidative stress and telomere length dynamics, also examining how each of the metabolic syndrome components individually affects the length. In this regard, there is strong scientific evidence that an increase in the number of metabolic syndrome components is associated with a shorter telomere length, oxidative damage at the lipid and DNA level, and inflammation, as well as its other components, such as obesity, hyperglycemia, and hypertension, while for dyslipidemia, there is a little more discrepancy. The difficulty for the correct treatment of metabolic syndrome lies in its multifactorial nature. Hence, there is a need to carry out more studies on healthy lifestyles during aging to prevent and reduce oxidative damage and telomere wear during aging, and consequently the progression of chronic degenerative diseases, thus improving the living conditions of older people.

Abstract

A great amount of scientific evidence supports that Oxidative Stress (OxS) can contribute to telomeric attrition and also plays an important role in the development of certain age-related diseases, among them the metabolic syndrome (MetS), which is characterised by clinical and biochemical alterations such as obesity, dyslipidaemia, arterial hypertension, hyperglycaemia, and insulin resistance, all of which are considered as risk factors for type 2 diabetes mellitus (T2DM) and cardiovascular diseases, which are associated in turn with an increase of OxS. In this sense, we review scientific evidence that supports the association between OxS with telomere length (TL) dynamics and the relationship with MetS components in aging. It was analysed whether each MetS component affects the telomere length separately or if they all affect it together. Likewise, this review provides a summary of the structure and function of telomeres and telomerase, the mechanisms of telomeric DNA repair, how telomere length may influence the fate of cells or be linked to inflammation and the development of age-related diseases, and finally, how the lifestyles can affect telomere length.

Effect of long work hours and shift work on high-sensitivity C-reactive protein levels among Korean workers

Objective We aimed to investigate the association between low-grade inflammation as indicated by high-sensitivity C-reactive protein (hsCRP) level and organizational factors, such as work hours and shift work. Methods We evaluated 7470 young and middle-aged workers who participated in the Korea National Health and Nutrition Examination Surveys from 2015-2018. Work hours were determined from self-reported questionnaires. Shift work was defined as a non-daytime fixed work schedule. An interaction effect between shift work and long work hours on the hsCRP level was estimated using relative excess risk due to interaction (RERI) and attributable proportion (AP) with 95% confidence intervals (CI). Results Increased hsCRP levels were prevalent in 25.2% of the study population. There was a significant association between long work hours and increased hsCRP, especially among middle-aged men [odds ratio (OR) 1.50 (95% CI 1.20-1.87) for moderately increased hsCRP and OR 1.62 (95% CI 1.14-2.30) for highly increased hsCRP]. There was a significant interaction effect between long work hours and shift work on increased hsCRP among middle-aged workers. The RERI were 0.03 (95% CI 0.02-0.04) and 0.56 (95% CI 0.45-0.68) among middle-aged men and women, respectively. The AP were 0.02 (95% CI 0.01-0.03) and 0.36 (95% CI 0.31-0.40) among middle-aged men and women, respectively. Conclusion There was no significant association between shift work and the level of hsCRP. Long work hours were related to low-grade inflammatory processes, but only in middle-aged workers. There was an interaction effect between long work hours and shift work for increased hsCRP, especially in middle-aged women.

WITHDRAWN: Can Traditional Chinese Medicine provide insights into controlling the COVID-19 pandemic: Serpentinization-induced lithospheric long-wavelength magnetic anomalies in Proterozoic bedrocks in a weakened geomagnetic field mediate the aberrant transformation of biogenic molecules in COVID-19 via magnetic catalysis

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Measuring plasma ferritin levels with two different methods: A comparison of Roche Cobas e601 versus Roche Cobas c501 (integrated modular system Roche Cobas 6000)

BACKGROUND

The aim of our study is to compare plasma ferritin levels found to be high or low in terms of reference range by means of electrochemiluminescence (ECLIA) and immunoturbidimetric method and to examine whether they can be used interchangeably.

METHODS

84 patients with high plasma ferritin level and 153 patients with low ferritin level according to the re ference range were included in the study. Plasma samples measured in Cobas e601 device with ECLIA were also measured as immunoturbidimetric Cobas c501 device. For method comparison, CLSI EP9-A3 Guideline was used. While the consistency between the methods were specified with Passing-Bablok regression analysis and Spearman cor relation analysis, bias error between the methods (bias%) was determined through Bland-Altman analysis.

RESULTS

Both high and low plasma ferritin levels measured with Cobas e601 module and determined high in terms of reference range were compared with the results found with cobas c501 module. The difference was found to be statistically significant (p<0.001). According to regression and correlation (for low plasma ferritin levels; r: 0.993, p<0.001, for high plasma ferritin levels; r: 0.966, p<0.001) results, the methods were in consistency with each other. Additionally, while the bias% value was found to be 10.4% for low plasma ferritin levels, it was found to be 12.6% for high ferritin levels.

CONCLUSIONS

Accordingly, we believe that, comparison with more samples especially in terms of different clinical decision levels is required in order to examine inter changeable use of immunoturbidimetric method in integrated devices and ECLIA.

Markers of iron status, blood pressure and incident hypertension among Chinese adults

BACKGROUND AND AIMS

The evidence on the relationship between markers of iron, blood pressure and hypertension are limited and inconsistent. This prospective cohort study aimed to investigate the relationship of serum ferritin (SF), transferrin, soluble transferrin receptor (sTFR) and haemoglobin on blood pressure and incident hypertension in the China Health and Nutrition Survey (CHNS) study.

METHODS AND RESULTS

We studied 8337 adults aged 18 years old or above from CHNS in 2009 to investigate the association of markers of iron and blood pressure (BP). Among them, 4509 non-hypertensive participants who completed follow up were included to investigate the association of markers of iron and hypertension development. Linear regression model was used to assess the association between markers of iron and BP. Cox regression model was used to examine the association of markers of iron and hypertension development. SF and serum sTFR concentration had a non-significant effect on incident hypertension. Transferrin and haemoglobin concentrations were positively associated with incident hypertension. Compared to the participants with the lowest tertile of transferrin, those with the highest tertile had a higher risk of developing hypertension [HR: 1.26, 95% CI (1.04, 1.53), P = 0.017]. Similarly, participants with the highest tertile of haemoglobin had a significantly higher risk of incident hypertension [HR: 1.27, 95% CI (1.01, 1.59), P = 0.038].

CONCLUSION

The current study found that haemoglobin and transferrin levels were positively associated with blood pressure and incident hypertension. Further research in different ethnic groups is required to confirm the association of the full range of markers of iron with BP and incident hypertension.