Insights into the ethnic differences in serum ferritin between black and white US adult men

Exploring ethnic differences in the distribution of blood test results in healthy adult populations to inform earlier cancer detection: a systematic review

BACKGROUND

In primary care, health professionals use blood tests to investigate nonspecific presentations to inform referral decisions. Reference ranges for the commonly used blood tests in western countries were developed in predominately White populations, and so may perform differently when applied to non-White populations. Knowledge of ethnic variation in blood test results in healthy/general populations could help address ethnic inequalities in cancer referral for diagnosis and outcomes.

OBJECTIVE

This systematic review explored evidence of ethnic differences in the distribution of selected blood test results among healthy/general populations to inform future research aimed at addressing inequalities in cancer diagnosis.

METHODS

We searched PubMed and EMBASE to identify studies reporting measures of haemoglobin, MCV, calcium, albumin, platelet count, and CRP in nondiseased adults from at least 2 different ethnic groups. Two reviewers independently screened studies, completed data extraction and quality assessment using an adapted Newcastle-Ottawa scale. Participants were stratified into White, Black, Asian, Mixed, and Other groups. Data were synthesised narratively and meta-analyses were conducted where possible.

RESULTS

A total of 47 papers were included. Black men and women have lower average values of haemoglobin, MCV, and albumin, and higher average values of CRP relative to their White counterparts. Additionally, Black men have lower average haemoglobin than Asian men, whereas Asian women have lower average CRP values when compared with White women.

CONCLUSIONS

There is evidence of ethnic differences in average values of haemoglobin, MCV, CRP, and albumin in healthy/general populations. Further research is needed to explore the reasons for these differences. Systematic review registration: CRD42021274580.

Evaluation of mean corpuscular volume among anemic people with HIV in North America following ART initiation

BACKGROUND

Anemia is common and associated with increased morbidity among people with HIV (PWH). Classification of anemia using the mean corpuscular volume (MCV) can help investigate the underlying causative factors of anemia. We characterize anemia using MCV among PWH receiving antiretroviral therapy (ART), and identify the risk factors for normocytic, macrocytic, and microcytic anemias.

METHODS

Including PWH with anemia (hemoglobin measure < 12.9 g/dL among men and < 11.9 g/dL among women) in the NA-ACCORD from 01/01/2007 to 12/31/2017, we estimated the annual distribution of normocytic (80-100 femtolitre (fL)), macrocytic (> 100 fL) or microcytic (< 80 fL) anemia based on the lowest hemoglobin within each year. Poisson regression models with robust variance and general estimating equations were used to estimate crude and adjusted prevalence ratios and 95% confidence intervals for risk factors for macrocytic (vs. normocytic) and microcytic (vs. normocytic) anemia stratified by sex.

RESULTS

Among 37,984 hemoglobin measurements that identified anemia in 14,590 PWH, 27,909 (74%) were normocytic, 4257 (11%) were microcytic, and 5818 (15%) were macrocytic. Of the anemic PWH included over the study period, 1910 (13%) experienced at least one measure of microcytic anemia and 3208 (22%) at least one measure of macrocytic anemia. Normocytic anemia was most common among both males and females, followed by microcytic among females and macrocytic among males. Over time, the proportion of anemic PWH who have macrocytosis decreased while microcytosis increased. Macrocytic (vs. normocytic) anemia is associated with increasing age and comorbidities. With increasing age, microcytic anemia decreased among females but not males. A greater proportion of PWH with normocytic anemia had CD4 counts ≤ 200 cells/mm3 and had recently initiated ART.

CONCLUSION

In anemic PWH, normocytic anemia was most common. Over time macrocytic anemia decreased, and microcytic anemia increased irrespective of sex. Normocytic anemia is often due to chronic disease and may explain the greater risk for normocytic anemia among those with lower CD4 counts or recent ART initiation. Identified risk factors for type-specific anemias including sex, age, comorbidities, and HIV factors, can help inform targeted investigation into the underlying causes.

Does Environmental Information Disclosure Improve the Health Level of Middle-Aged and Old Residents? Evidence From China

Objective

The purpose of this study is to empirically examine the impact of environmental information disclosure on the health of middle-aged and old residents and investigate whether such disclosure can improve the health of middle-aged and old residents.

Methods

This study matches the data of the Pollution Information Transparency Index (PITI) and China Health and Retirement Longitudinal Study in 2018 and uses the ordered logistic regression model to assess the impact of environmental information disclosure on the health of middle-aged and old residents. Furthermore, stepwise regression, ordinary least square, and ordered probit regression models are used for robustness tests. The IV-Ordered probit regression model solves the endogenous problem.

Results

Environmental information disclosure has a significant positive correlation with the health level of middle-aged and old residents. After the robustness test and endogenous problem handling, this conclusion still holds. Estimation results show that when PITI increases by 1 unit, the probability of improving the self-reported health level and actual health level of middle-aged and old residents increases by 1 and 0.87%, respectively. The impact of environmental information disclosure on the health of middle-aged and old residents also has significant regional heterogeneity. Specifically, the impact is mainly reflected in the central region of China.

Conclusion

Environmental information disclosure can improve the health of middle-aged and old residents. To improve the health of middle-aged and old residents, it is necessary to implement and enhance the environmental information disclosure system continuously. The anti-driving effect of environmental information disclosure on the treatment of environmental pollution must be intensified further, particularly focusing on the central region of China, where is more polluted and more concentrated than other regions.

Impact of psychological contract fulfillment on well-being through the mediation of psychological distress: unveiling the evidences from banking sector

Purpose

This paper aims to explore the content of the psychological contract (PC), i.e. work-family conflict (WFC), family-work conflict (FWC), work overload (WO) and work autonomy (WA) and its impact on well-being (WB), i.e. job satisfaction (JS), family satisfaction (FS), life satisfaction (LS), through the mediation of psychological distress (PD).

Design/methodology/approach

The current study has adopted a quantitative approach and a cross-sectional research design with a snowball sampling technique. The sample size consists of 400 employees from the banking sector. SPSS and AMOS 20v has been used for structural equation modelling to give empirical findings from the responses collected.

Findings

The current study has checked the relationship between PC and WB through the mediation analysis of PD. WA was not affecting the WB of banking employees. The study found that there was partial mediation. It was also proven that the lower the breach of PC lower the PD, and the higher the WB.

Originality/value

The current study has tried to explain the content of PC among the employees of the banking sector and how that is associated with WB. There was limited work from which showcase the WFC, FWC and WO from the view of PC theory, and it affects different WB, i.e. JS, LS and FS.

Prevalence of Iron Deficiency and its Sociodemographic Patterning in Indian Children and Adolescents: Findings from the Comprehensive National Nutrition Survey 2016-18

BACKGROUND

Anemia control programs in India focus mainly on the measurement of hemoglobin in response to iron-folic acid supplementation. However, representative national estimates of iron deficiency (ID) are not available.

OBJECTIVES

The objective of the present study was to evaluate ID prevalence among children and adolescents (1-19 y) using nationally representative data and to examine the sociodemographic patterning of ID.

METHODS

Cross-sectional data from the Comprehensive National Nutrition Survey in children (1-4 y: n = 9635; 5-9 y: n = 11,938) and adolescents (10-19 y; n = 11,507) on serum ferritin (SF) and other biomarkers were analyzed to determine inflammation-adjusted ID prevalence [SF (μg/L): <12 in 1-4 y and <15 in 5-19 y] and its relation to sociodemographic indicators. Multiple-regression analyses were conducted to identify the exposure associations of iron status. In addition, the relation between SF and hemoglobin was assessed as an indicator of iron utilization in different wealth quintiles.

RESULTS

ID prevalence was higher in 1- to 4-y-old children (31.9%; 95% CI: 31.0%, 32.8%) and adolescent girls (30.4%; 95% CI: 29.3%, 31.5%) but lower in adolescent boys and 5- to 9-y-old children (11%-15%). In all age groups, ID prevalence was higher in urban than in rural participants (1-4 y: 41% compared with 29%) and in those from richer quintiles (1-4 y: 44% in richest compared with 22% in poorest), despite adjustment for relevant confounders. SF significantly interacted with the wealth index, with declining trends in the strength of association between hemoglobin and SF from the richest to the poorest groups suggesting impaired iron utilization for hemoglobin synthesis in poorer wealth quintiles.

CONCLUSIONS

ID prevalence was indicative of moderate (in preschool children and adolescent girls) or mild (in 5- to 9-y-old children and adolescent boys) public health problem with significant variation by state and age. Focusing on increasing iron intake alone, without addressing the multiple environmental constraints related to poverty, may not result in intended benefits.

Establishment of reference intervals of ten commonly used clinical chemistry analytes: a real-world study in China

Aim: This real-world study was aimed at establishing reference intervals (RIs) of ten commonly used clinical chemistry analytes (total cholesterol, triglycerides, Apo A1, Apo B, creatine kinase (CK), CK isoenzyme MB, glucose, alkaline phosphatase, γ-glutamyltransferase and blood urea nitrogen) in an apparently healthy population in China. Materials & methods: A total of 17,356 healthy participants aged 18-79 years who underwent check-up at MJ Health Check-up Center were included. The establishment of RIs was performed according to the Clinical and Laboratory Standards Institute EP28-A3c guideline. Roche Cobas c701 automatic analyzer (Roche Diagnostics, Mannheim, Germany) was employed to measure the concentrations of analytes. Results: Total cholesterol, triglycerides, Apo B, CK, alkaline phosphatase, glucose, γ-glutamyltransferase and blood urea nitrogen required gender and age-specific partitioning. Conclusion: The RIs established in this study were parallel to current national standards and previous RIs established in Chinese population. Real-world studies may play an important and practical role in the determination of RIs in the future.

Eliminating race-based reference ranges in haematology: a call to action

In haematology, as in all of medicine, the use of reference intervals for laboratory variables is essential to define disease states and inform treatment decisions. There are many haematological variables, including haemoglobin, mean corpuscular volume, absolute neutrophil count, and iron indices, that are often reported to be different on the basis of a person's race or ethnicity. Although there are many haematological conditions with a genetic basis, such that it is appropriate to consider ancestry in the diagnostic algorithm, defining pathology on the basis of a social construct such as race is unacceptable. The inclusion of separate thresholds or simple statements that so-called normal values vary by race further validates the common misperception that there are physiological differences between Black and white patients. These statements might have downstream effects on diagnostic and treatment decisions that exacerbate existing racial health disparities. In this Viewpoint, we argued for the removal of race-based reference intervals across haematology.

Ethnic Differences in Iron Status

Iron is unique among all minerals in that humans have no regulatable excretory pathway to eliminate excess iron after it is absorbed. Iron deficiency anemia occurs when absorbed iron is not sufficient to meet body iron demands, whereas iron overload and subsequent deposition of iron in key organs occur when absorbed iron exceeds body iron demands. Over time, iron accumulation in the body can increase risk of chronic diseases, including cirrhosis, diabetes, and heart failure. To date, only ∼30% of the interindividual variability in iron absorption can be captured by iron status biomarkers or iron regulatory hormones. Much of the regulation of iron absorption may be under genetic control, but these pathways have yet to be fully elucidated. Genome-wide and candidate gene association studies have identified several genetic variants that are associated with variations in iron status, but the majority of these data were generated in European populations. The purpose of this review is to summarize genetic variants that have been associated with alterations in iron status and to highlight the influence of ethnicity on the risk of iron deficiency or overload. Using extant data in the literature, linear mixed-effects models were constructed to explore ethnic differences in iron status biomarkers. This approach found that East Asians had significantly higher concentrations of iron status indicators (serum ferritin, transferrin saturation, and hemoglobin) than Europeans, African Americans, or South Asians. African Americans exhibited significantly lower hemoglobin concentrations compared with other ethnic groups. Further studies of the genetic basis for ethnic differences in iron metabolism and on how it affects disease susceptibility among different ethnic groups are needed to inform population-specific recommendations and personalized nutrition interventions for iron-related disorders.

Effects of Land Urbanization on Smog Pollution in China: Estimation of Spatial Autoregressive Panel Data Models

Studying the impact of land urbanization on smog pollution has important guiding significance for the sustainable development of cities. This study adds the spatial effect between regions into the research framework of smog pollution control in China. On the basis of a panel dataset of 31 province-level administrative regions in China from 2000 to 2017, we investigate the impact of land urbanization on smog pollution. We construct a spatial weight matrix and use Moran’s I statistic and the spatial autoregressive panel data model. The research results show that land urbanization and smog pollution have an inverted U-shaped relationship. With the advancement of land urbanization, the area’s smog pollution first increases and then decreases. However, in general, China has not passed the inflection point and is still at a stage where increasing land urbanization rate aggravates smog pollution. Moreover, the country’s smog pollution has a significant spatial positive correlation that shows agglomeration. In that context, multiple environmental governance entities, including the government, enterprises, and the public, need to collaborate on measures to reduce smog pollution. Future urban construction in China will need to integrate solutions that address the current nexus between urbanization and smog pollution to achieve green and sustainable development.

Decreased lung function is associated with elevated ferritin but not iron or transferrin saturation in 42,927 healthy Korean men: A cross-sectional study

Objectives

Though elevated ferritin level and decreased lung function both predispose people to cardio-metabolic disease, few reports have investigated the association between them. Furthermore, it remains unclear whether the association reflects a change in iron stores or an epiphenomenon reflecting metabolic stress. Therefore, we looked for possible associations between ferritin, iron, and transferrin saturation (TSAT) and lung function to clarify the role of iron-related parameters in healthy men.

Methods

We conducted a cohort study of 42,927 healthy Korean men (mean age: 38.6 years). Percent predicted forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) were categorized into quartiles. Adjusted odds ratios (aORs) and 95% confidence intervals (using the highest quartile as reference) were calculated for hyperferritinemia, high iron, and high TSAT after controlling for potential confounders.

Results

The median ferritin level was 199.8 (141.5–275.6) ng/mL. The prevalence of hyperferritinemia (defined as >300 ng/mL) was 19.3%. Subjects with hyperferritinemia had lower FEV1% and FVC% than those with normal ferritin level with a slight difference, but those were statistically significant (99.22% vs.99.61% for FEV1%, p = 0.015 and 98.43% vs. 98.87% for FVC, p = 0.001). However, FEV1/FVC ratio was not significantly different between groups (P = 0.797). Compared with the highest quartile, the aORs for hyperferritinemia across decreasing quartiles were 1.081 (1.005–1.163), 1.100 (1.007–1.200), and 1.140 (1.053–1.233) for FEV1% (p for trend = 0.007) and 1.094 (1.018–1.176), 1.101 (1.021–1.188), and 1.150 (1.056–1.252) for FVC% (p for trend = 0.001). However, neither FEV1% nor FVC% was associated with iron or TSAT.

Conclusions

Hyperferritinemia was associated with decreased lung function in healthy Korean men, but iron and TSAT were not. Longitudinal follow-up studies are required to validate our findings.

Reference intervals established using indirect method for serum ferritin assayed on Abbott Architect i2000SR analyzer in Chinese adults

BACKGROUND

Serum ferritin (SF) test has been widely used in clinical practice. However, its reference intervals (RIs) vary depending on the analytical method and ethnic origin. This study was to establish the RIs using indirect method for SF in Chinese adults.

METHODS

SF was assayed on Abbott i2000SR analyzer. The SF test results of all health examinees (8913 males aged 18-93 years and 5397 females aged 18-90 years) between December 2010 and April 2019 were obtained from our laboratory information system. After Box-Cox transformation of raw data and exclusion of outliers, parametric and non-parametric approaches were used to calculate 95% RIs. The correlation between SF levels and ages, and the differences in SF levels between subgroups were also analyzed.

RESULTS

SF levels in females were significantly different from those in males (Z = 88.96, Z* = 23.17; Z > Z*) and showed a weak positive correlation with age (r = .466, P < .0001). The RIs based on parametric approach in males were 66.12-561.58 µg/L, whereas in all females were 3.59-269.59 µg/L, females aged <50 years 3.26-148.02 µg/L and those aged ≥50 years 17.28-303.27 µg/L. The RIs based on non-parametric approach in males were 65.00-571.37 µg/L whereas in all females were 4.00-254.00 µg/L, females aged <50 years 4.00-152.00 µg/L and those aged ≥50 years 16.00-304.05 µg/L.

CONCLUSIONS

Our indirect RIs for SF were markedly different from the manufacturer's recommended RIs and might be more suitable for Chinese adults, which would be helpful in interpreting laboratory data and clinical decision-making.

Sensory Function, Measured as Active Discriminative Touch, is Associated With Dexterity after Stroke

BACKGROUND

Reduced dexterity is common after stroke, which can affect the ability to perform upper limb daily activities. To improve upper limb function after stroke, it is important to understand which factors are most associated with dexterity.

OBJECTIVE

To evaluate how several factors are associated with dexterity after stroke.

DESIGN

Cross-sectional study.

SETTING

A university hospital.

PARTICIPANTS

A convenience sample of 75 persons (54 men and 21 women, mean age 66 years) with mild to moderate impairments of the upper limb after stroke.

METHODS

Dexterity and potentially associated factors (age, gender, affected hand, social situation, vocational situation, grip strength, spasticity, sensory function, and pain) were evaluated by linear regression models.

MAIN OUTCOME MEASUREMENTS

Dexterity was measured with the mini Sollerman Hand Function Test, sensory function with both the Fugl-Meyer Assessment of the Upper Extremity (to assess light touch and proprioception) and the Shape Texture Identification Test (to assess active discriminative touch), spasticity with the Modified Ashworth Scale, and grip strength with the Grippit dynamometer.

RESULTS

Active discriminative touch had the strongest association with dexterity, explaining 46% of the variance. When spasticity and grip strength were added, the explained variance increased to 57% in the final multivariate model.

CONCLUSIONS

This study indicates that sensory function in terms of active discriminative touch is a major contributing factor to dexterity in persons with mild to moderate stroke, whereas spasticity and grip strength may be of lesser importance.

LEVEL OF EVIDENCE

III.

Which clinical and sociodemographic determinants are associated with self-perceived manual ability at one year after stroke?

Purpose: To evaluate the impact of multiple potential sociodemographic and clinical stroke-related determinants on self-perceived manual ability in an unselected sample of individuals 12 months after first-ever stroke.Methods: A cross-sectional sample of 68 participants (mean age 66) with UE impairments were followed up at 12 months post stroke. Stroke severity at onset was moderate for the majority. Manual ability was assessed by the patient-reported outcome measure ABILHAND Questionnaire. Determinants included in the multivariate regression analysis were age, gender, living situation, vocational situation, affected hand, stroke severity at onset and UE disability (motor function, sensory function, joint motion, pain, grip strength, spasticity and activity capacity) at 12 months post stroke.Results: The strongest associated determinants with self-perceived manual ability were UE motor function and UE activity capacity at 12 months post-stroke. UE motor function together with age and grip strength explained 65% of the variance in one final multivariate model. UE activity capacity and grip strength explained 62% of the variance in a second final model.Conclusion: In order to understand self-perceived difficulties in manual ability in daily activities in persons with stroke, assessments of UE motor function and activity capacity are recommended.Implications for rehabilitationThe ultimate goal of the upper extremity rehabilitation after stroke is to regain ability to use the UE in daily activities that are important to the individual in his or her own environment.This requires a good understanding of factors that are associated with self-perceived manual ability in order to tailor effective rehabilitation interventions.Upper extremity motor function and activity capacity are the strongest determinants associated with self-perceived manual ability one year after stroke.These factors are recommended to be included in the assessment battery in stroke to fully understand the disability in daily life.

Ethnic and genetic factors of iron status in women of reproductive age

Background: African Americans are at increased risk of iron deficiency (ID) but also have higher serum ferritin (SF) concentrations than those of the general population. The Hemochromatosis and Iron Overload Screening (HEIRS) Study was a multicenter study of ethnically diverse participants that tested for the hemochromatosis (HFE) C282Y genotype and iron status.Objective: We sought to determine the prevalence and predictors of ID (SF concentration ≤15 μg/L) and elevated iron stores (SF concentration >300 μg/L) in HEIRS women of reproductive age (25-44 y).Design: The HEIRS Study was a cross-sectional study of iron status and HFE mutations in primary care patients at 5 centers in the United States and Canada. We analyzed data for women of reproductive age according to whether or not they were pregnant or breastfeeding at the time of the study.Results: ID was present in 12.5% of 20,080 nonpregnant and nonbreastfeeding women compared with 19.2% of 1962 pregnant or breastfeeding women (P < 0.001). Asian American ethnicity (OR ≤0.9; P ≤ 0.049) and HFE C282Y (OR ≤0.84; P ≤ 0.060) were independently associated with a decreased risk of ID in nonpregnant and nonbreastfeeding women and in pregnant or breastfeeding women. Hispanic ethnicity (OR: 1.8; P < 0.001) and African American ethnicity (OR: 1.6; P < 0.001) were associated with an increased risk of ID in nonpregnant and nonbreastfeeding women. Elevated iron stores were shown in 1.7% of nonpregnant and nonbreastfeeding women compared with 0.7% of pregnant or breastfeeding women (P = 0.001). HFE C282Y homozygosity had the most marked independent association with elevated iron stores in nonpregnant and nonbreastfeeding women and in pregnant or breastfeeding women (OR >49.0; P < 0.001), but African American ethnicity was also associated with increased iron stores in both groups of women (OR >2.0; P < 0.001). Asian American ethnicity (OR: 1.8; P = 0.001) and HFE C282Y heterozygosity (OR: 1.9; P = 0.003) were associated with increased iron stores in nonpregnant and nonbreastfeeding women.Conclusions: Both ID and elevated iron stores are present in women of reproductive age and are influenced by ethnicity and HFE C282Y. Efforts to optimize iron status should keep these findings in view. This study was registered at clinicaltrials.gov as NCT03276247.

Introduction to workshop on iron screening and supplementation in iron-replete pregnant women and young children

The NIH Office of Dietary Supplements convened a public workshop on iron screening and supplementation in iron-replete pregnant women and young children in 2016 in Bethesda, Maryland. The starting point for the workshop was the recent reports from the US Preventive Services Task Force concluding that there was insufficient evidence to evaluate the benefits and harms associated with iron screening and routine supplementation among asymptomatic pregnant women and young children (6-24 mo old) in the United States. The goal of the workshop was to explore and refine understanding about the existing knowledge gaps and research needs associated with these preventive services for these groups. Given the focus on the United States, planning for the workshop took into account the higher iron status in the United States compared with developing countries and, in turn, included a focus on iron-replete individuals consistent with the U-shaped risk curve for nutrient-health relations. Topic areas included adaptations in iron homeostasis associated with pregnancy and young childhood, the impact of inflammation, measurement of iron status, current estimates of iron status for pregnant women and young children in the United States and in Europe, and emerging evidence suggesting adverse effects associated with iron supplementation of iron-replete individuals. A crosscutting dialogue conducted at the close of the workshop formed the basis for a workshop summary that specified evidence gaps and research needs in a range of areas centered on the relation of these adaptations of iron homeostasis with the response to and risk from iron supplementation as well as the need for indicators informative of the full continuum of iron status and based on health outcomes, not just erythropoiesis.

Association of exposure to manganese and iron with relaxation rates R1 and R2*- magnetic resonance imaging results from the WELDOX II study

OBJECTIVE

Magnetic resonance imaging is a non-invasive method that allows the indirect quantification of manganese (Mn) and iron (Fe) accumulation in the brain due to their paramagnetic features. The WELDOX II study aimed to explore the influence of airborne and systemic exposure to Mn and Fe on the brain deposition using the relaxation rates R1 and R2* as biomarkers of metal accumulation in regions of interest in 161 men, including active and former welders.

MATERIAL AND METHODS

We obtained data on the relaxation rates R1 and R2* in regions that included structures within the globus pallidus (GP), substantia nigra (SN), and white matter of the frontal lobe (FL) of both hemispheres, as well as Mn in whole blood (MnB), and serum ferritin (SF). The study subjects, all male, included 48 active and 20 former welders, 41 patients with Parkinson's disease (PD), 13 patients with hemochromatosis (HC), and 39 controls. Respirable Mn and Fe were measured during a working shift for welders. Mixed regression models were applied to estimate the effects of MnB and SF on R1 and R2*. Furthermore, we estimated the influence of airborne Mn and Fe on the relaxation rates in active welders.

RESULTS

MnB and SF were significant predictors of R1 but not of R2* in the GP, and were marginally associated with R1 in the SN (SF) and FL (MnB). Being a welder or suffering from PD or HC elicited no additional group effect on R1 or R2* beyond the effects of MnB and SF. In active welders, shift concentrations of respirable Mn>100μg/m³ were associated with stronger R1 signals in the GP. In addition to the effects of MnB and SF, the welding technique had no further influence on R1.

CONCLUSIONS

MnB and SF were significant predictors of R1 but not of R2*, indicative of metal accumulation, especially in the GP. Also, high airborne Mn concentration was associated with higher R1 signals in this brain region. The negative results obtained for being a welder or for the techniques with higher exposure to ultrafine particles when the blood-borne concentration was included into the models indicate that airborne exposure to Mn may act mainly through MnB.

Indices of iron homeostasis correlate with airway obstruction in an NHANES III cohort

Cigarette smoking results in the accumulation of iron both systemically and locally, in the lung thereby causing imbalance in iron homeostasis. This disruption in iron homeostasis can be associated with oxidative stress and consequent tissue injury. Therefore, in this study, we tested the association between iron homeostasis and airway obstruction by examining a large cohort of smokers and non-smokers for relationships between 1) serum ferritin and iron concentrations and transferrin saturation and 2) forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), and their ratio (FEV₁/FVC). Data from the National Health and Examination Survey III were analyzed. The study population included persons aged 20 years and above with their following data recorded: race, gender, serum ferritin and iron concentrations, and transferrin saturation; the final sample number was 7,251. In the total population, Pearson correlation coefficients between 1) serum ferritin and iron concentrations and transferrin saturation and 2) FVC and FEV₁ were significantly positive; whereas those between 1) serum ferritin concentrations and transferrin saturation and 2) FEV₁/FVC were significantly negative. With separate analyses, serum ferritin concentrations demonstrated positive associations with FVC and FEV₁ but an inverse relationship with FEV₁/FVC in smokers and non-smokers. Serum ferritin levels increased with worsening airway obstruction among smokers, and its highest concentrations were found among those with the lowest values of FEV₁/FVC ratio (<60%). Comparable to cigarette smokers, serum ferritin concentrations among non-smokers were greatest in those with the lowest FEV₁/FVC ratio. Furthermore, elevated levels of serum iron and saturation of transferrin also corresponded with decreased FEV₁/FVC ratio among non-smokers. Thus, we conclude that indices of iron homeostasis are associated with airway obstruction in both smokers and non-smokers.

The prognostic value of the serum ferritin in a southern Brazilian cohort of patients with Gaucher disease

The clinical utility of serum ferritin as a biomarker of disease severity and prognosis in Gaucher disease (GD) is still debated. Here, we aimed to evaluate ferritin and its relation to clinicolaboratory parameters of GD patients seen at the Reference Center for Gaucher Disease of Rio Grande do Sul, Brazil, so as to gather evidence on the utility of ferritin as a biomarker of this condition. A retrospective chart review was performed collecting pre-and posttreatment data from GD patients. Eighteen patients with ferritin levels available before and after treatment were included in the study. Nine of these participants were males, and seventeen had type I GD. All patients were given either enzyme replacement (n = 16) or substrate reduction therapy (n = 2), and ferritin was found to decrease from 756 [318-1441] ng/mL at baseline to 521 [227-626] ng/mL (p=0.025) after 28.8 month soft treatment. Serum ferritin levels did not correlate with measures of disease severity, but showed an association with age at onset of treatment (ρ= 0.880; n = 18; p < 0.001). In conclusion, although serum ferritin did not correlate with disease severity, after a median 28.8 months of treatment, clinical outcomes had clearly improved, and ferritin levels had decreased.

Gamma-Glutamyltransferase: A Predictive Biomarker of Cellular Antioxidant Inadequacy and Disease Risk

Gamma-glutamyltransferase (GGT) is a well-established serum marker for alcohol-related liver disease. However, GGT's predictive utility applies well beyond liver disease: elevated GGT is linked to increased risk to a multitude of diseases and conditions, including cardiovascular disease, diabetes, metabolic syndrome (MetS), and all-cause mortality. The literature from multiple population groups worldwide consistently shows strong predictive power for GGT, even across different gender and ethnic categories. Here, we examine the relationship of GGT to other serum markers such as serum ferritin (SF) levels, and we suggest a link to exposure to environmental and endogenous toxins, resulting in oxidative and nitrosative stress. We observe a general upward trend in population levels of GGT over time, particularly in the US and Korea. Since the late 1970s, both GGT and incident MetS and its related disorders have risen in virtual lockstep. GGT is an early predictive marker for atherosclerosis, heart failure, arterial stiffness and plaque, gestational diabetes, and various liver diseases, including viral hepatitis, other infectious diseases, and several life-threatening cancers. We review literature both from the medical sciences and from life insurance industries demonstrating that serum GGT is a superior marker for future disease risk, when compared against multiple other known mortality risk factors.

Marked Biological Variance in Endocrine and Biochemical Markers in Childhood: Establishment of Pediatric Reference Intervals Using Healthy Community Children from the CALIPER Cohort

BACKGROUND

Reference intervals are indispensable in evaluating laboratory test results; however, appropriately partitioned pediatric reference values are not readily available. The Canadian Laboratory Initiative for Pediatric Reference Intervals (CALIPER) program is aimed at establishing the influence of age, sex, ethnicity, and body mass index on biochemical markers and developing a comprehensive database of pediatric reference intervals using an a posteriori approach.

METHODS

A total of 1482 samples were collected from ethnically diverse healthy children ages 2 days to 18 years and analyzed on the Abbott ARCHITECT i2000. Following the CLSI C28-A3 guidelines, age- and sex-specific partitioning was determined for each analyte. Nonparametric and robust methods were used to establish the 2.5th and 97.5th percentiles for the reference intervals as well as the 90% CIs.

RESULTS

New pediatric reference intervals were generated for 14 biomarkers, including α-fetoprotein, cobalamin (vitamin B12), folate, homocysteine, ferritin, cortisol, troponin I, 25(OH)-vitamin D [25(OH)D], intact parathyroid hormone (iPTH), thyroid-stimulating hormone, total thyroxine (TT4), total triiodothyronine (TT3), free thyroxine (FT4), and free triiodothyronine. The influence of ethnicity on reference values was also examined, and statistically significant differences were found between ethnic groups for FT4, TT3, TT4, cobalamin, ferritin, iPTH, and 25(OH)D.

CONCLUSIONS

This study establishes comprehensive pediatric reference intervals for several common endocrine and immunochemical biomarkers obtained in a large cohort of healthy children. The new database will be of global benefit, ensuring appropriate interpretation of pediatric disease biomarkers, but will need further validation for specific immunoassay platforms and in local populations as recommended by the CLSI.

Traditional food intake is correlated with iron stores in Canadian Inuit men

Accelerated loss of traditional lifestyles may place Inuit at risk of iron depletion given that anemia has been observed among Arctic men. The objectives of this study were to determine the prevalence of anemia, storage iron depletion, and iron overload and to identify correlates of iron status in Canadian Inuit men. In a cross-sectional survey of 994 men in the International Polar Year Inuit Health Survey, 2007-2008, hemoglobin, serum ferritin (SF), soluble transferrin receptor (on a subset), CRP, RBC fatty acid composition, and Helicobacter pylori serology were measured in venous blood drawn from fasting men. Anthropometric, dietary, sociodemographic, and health data were collected. Dietary and nondietary correlates of iron status were assessed with multiple linear and logistic models. For men with CRP ≤10 mg/L (n = 804), 6.5% had depleted, 19.8% had low, and 10.3% had elevated iron stores. Anemia was moderately prevalent (16.1%), but iron deficiency anemia was less common (2.4%). There was a low probability of dietary iron inadequacy (2.4% < Estimated Average Requirement) and excess iron intakes (10.7% > Tolerable Upper Intake Level). Food-insecure men and those without a household hunter had a higher risk of low or depleted iron stores. Adiposity, traditional food intake, long-chain RBC PUFA status, and inflammation were positively associated with SF and food insecurity, smoking, and H. pylori seropositivity were negatively associated with SF. Despite a moderate prevalence of anemia, iron stores are largely adequate in this population, although lower than expected based on iron intake. The regulation of iron metabolism in this population and the high prevalence of anemia in older men warrants further investigation.

Utilization of iron from an animal-based iron source is greater than that of ferrous sulfate in pregnant and nonpregnant women

Heme iron absorption during pregnancy and the role of hepcidin in regulating dietary heme iron absorption remains largely unexplored. The objective of this research was to examine relative differences in heme (animal based) and nonheme (ferrous sulfate) iron utilization. This study was undertaken in 18 pregnant (ages 16-32 y; wk 32-35 of gestation) and 11 nonpregnant women (ages 18-27 y). Women were randomly assigned to receive both an animal-based heme meal (intrinsically labeled (58)Fe pork) and labeled ferrous sulfate ((57)Fe) fed on alternate days. Blood samples obtained 2 wk postdosing were used to assess iron status indicators and serum hepcidin and iron utilization based on RBC incorporation of iron isotopes. Heme iron utilization was significantly greater than nonheme iron utilization in the pregnant (47.7 ± 14.4 vs. 40.4 ± 13.2%) and nonpregnant women (50.1 ± 14.8 vs. 15.3 ± 9.7%). Among pregnant women, utilization of nonheme iron was associated with iron status, as assessed by the serum transferrin receptor concentration (P = 0.003; r(2) = 0.43). In contrast, heme iron utilization was not influenced by maternal iron status. In the group as a whole, women with undetectable serum hepcidin had greater nonheme iron utilization compared with women with detectable serum hepcidin (P = 0.02; n = 29); however, there were no significant differences in heme iron utilization. Our study suggests that iron utilization from an animal-based food provides a highly bioavailable source of dietary iron for pregnant and nonpregnant women that is not as sensitive to hepcidin concentrations or iron stores compared with ferrous sulfate.