Association of age, sex, and race with body iron stores in adults: analysis of NHANES III data

The association between higher serum ferritin level and lower bone mineral density is prominent in women ≥45 years of age (KNHANES 2008-2010)

SUMMARY

Data gathered from a nationally representative cohort demonstrate that higher serum ferritin levels are significantly associated with lower bone mass at various skeletal sites and the increased prevalence of osteoporosis and fractures, especially in women ≥45 years of age.

INTRODUCTION

Despite extensive in vitro and in vivo studies showing the detrimental effects of iron on bone metabolism, the clinical studies relating to osteoporosis-related phenotypes have not been evaluated extensively. In the present study, we investigated and compared the association between serum ferritin and bone mineral density (BMD), depending on the stratified age groups in both genders.

METHODS

This is a population-based, cross-sectional study from the Korea National Health and Nutrition Examination Surveys, including 14,017 Koreans (6,817 men and 7,200 women) aged 10-80 years. BMD was measured using dual X-ray absorptiometry, and osteoporosis was diagnosed by the World Health Organization definition.

RESULTS

Initially, we divided the subjects into three age groups, based on the patterns of age-related BMD changes in this national cohort (i.e., ≤24, 25-44, and ≥45 years old). Serum ferritin concentrations were inversely associated with BMD values at all measured sites after adjustment for confounders, only in women ≥45 years of age (P = 0.041 to <0.001). Furthermore, when we divided these women into serum ferritin quartiles, the odds for prevalent osteoporosis and fractures were 1.55-fold (95 % CI = 1.09-2.23) and 1.52-fold (95 % CI = 1.02-2.27) higher, respectively, in subjects in the highest quartile compared with those in the lowest quartile.

CONCLUSIONS

These results provide the first clinical evidence that the associations between serum ferritin level and bone parameters could be the most prominent in women ≥45 years of age.

Association between serum ferritin levels and risk of the metabolic syndrome in Chinese adults: a population study

Ferritin is a ubiquitous intracellular protein that can store and release iron and act as a buffer against iron deficiency and iron overload. Ferritin is widely used as a clinical biomarker to evaluate iron status. Increased serum ferritin concentrations have been reported to be associated with metabolic syndrome (MetS) features. However, serum ferritin concentrations differ significantly according to sex and ethnicity, and the data concerning the relationship between serum ferritin concentrations and MetS in Asian men and women are conflicting. This study aimed to explore the relationship between serum ferritin and MetS in Chinese population. Fasting blood samples and anthropometric data collected on 8,441 adults aged 18 and older in 2009 as part of the China Health and Nutrition Survey, a large-scale longitudinal, household-based survey in China. Data was collected by trained physicians and biomarkers were measured with Hitachi Clinical Autoanalyzer 7600 D model and P model. Median levels of serum ferritin were significantly higher in men compared with women (121.9 vs. 51.0 ng/ml, P < 0.001), and significantly lower in non metabolic syndrome population with MetS population (73.2 vs. 106.0 ng/ml, P < 0.001). The difference remained significant after further adjusted for age, nationality, Body mass index (BMI), smoking status, and alcohol consumption. For both men and women, the highest prevalence of MetS occurred in the highest quartile of serum ferritin. The odds ratios increased progressively across the ferritin quartiles (P<0.001 for trend). Increased serum ferritin concentrations are associated with the metabolic syndrome among men and women in China.

Serum ferritin level is higher in male adolescents with obesity: results from the Korean National Health and Nutrition Examination Survey 2010

PURPOSE

Previous reports show an association between high serum ferritin levels and metabolic syndrome (MS) in adults. In adolescents, little information is available with obesity and serum ferritin levels.

METHODS

This is a cross-sectional study. Data were obtained from the 5th Korean National Health and Nutrition Examination Survey (K-NHANES) conducted during 2010 by the Korean Ministry of Health and Welfare. A total of 849 subjects aged 10-18 years participated in the 2010 survey. A body mass index (BMI) ≥95th percentile for age and sex or a BMI ≥25 was used to diagnose as obesity.

RESULTS

The weighted prevalence of obesity was 13.4% (62/462) in male and 8.5% (33/387) in female. We observed significantly higher serum ferritin in male than in female (mean±standard error [SE], 50.5±2.3 µU/L vs. 30.6±1.3 µU/L; P<0.0001). In male, serum ferritin is positively correlated with age (P<0.0001). White blood cell (WBC) count, serum fasting blood sugar, triglyceride (TG), total cholesterol, low-density lipoprotein, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), systolic and diastolic blood pressure, and ferritin levels were higher and high-density lipoprotein (HDL) were lower in the obesity than in the normal group. In female adolescents, WBC count, TG, insulin, and HOMA-IR were higher and HDL were lower in the obesity than in the normal group. In male, serum ferritin levels showed positive association with obesity (β=21.196, P=0.016).

CONCLUSION

Serum ferritin levels appear to be associated with obesity in Korean male adolescents.

Toenail iron, genetic determinants of iron status, and the risk of glioma

PURPOSE

Iron is essential for oxygen transport and oxidative metabolism; however, elevated iron stores can trigger overproduction of reactive oxygen species and induce DNA damage. Little is known about the association between body iron stores and glioma risk. This study examined the associations of iron levels measured in toenails and genetic variants linked to body iron stores with risk of glioma in a clinic-based case-control study.

METHODS

Samples were collected a median of 24 days following glioma diagnosis in the cases (10th-90th percentile, range: 10-44 days). Nail iron levels were measured in 300 cases and 300 controls using neutron activation analysis. A total of 24 genetic variants associated with iron status were genotyped in 622 cases and 628 controls. Logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for glioma risk according to toenail iron and the examined genotypes.

RESULTS

No association was observed between toenail iron and glioma risk when restricting to cases with nails collected within ~3 weeks of diagnosis (OR = 0.93; 95 % CI 0.46, 1.87 comparing those with high (≥14 μg/g) vs. low (<6 μg/g) iron levels). In contrast, an inverse association with increasing iron was observed after restricting to cases with a delay of 3 weeks or greater (OR = 0.42; 95 % CI 0.19, 0.95), reflecting potentially insidious effects of advancing disease on iron levels among the cases. No associations were observed for any of the examined genetic variants.

CONCLUSION

The results do not support a role for body iron stores as a determinant of glioma risk.

Brain iron accumulation in aging and neurodegenerative disorders

Over the decades, various studies have established an association between accumulation of iron and both aging and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Excess levels of iron can lead to increased oxidative stress through Fenton chemistry, and depletion of iron can similarly have deleterious effects. In addition, metal ions are known to be involved in both Alzheimer's disease and Parkinson's disease protein aggregation. Metal ion chelators have been extensively investigated in preclinical models, and may prove to be appropriate for modulating brain iron levels in age-related neurodegenerative disorders. Investigating age-related iron deposition is vital, and can possibly aid in determining at-risk groups and diagnosing neurodegenerative diseases at an early stage. Novel imaging methods have enabled researchers to examine iron deposition in vivo, and offer a noninvasive method of monitoring the progression of accumulation, and possible therapeutic effects of chelating compounds.

Reduction of iron stores and clinical outcomes in peripheral arterial disease: outcome comparisons in smokers and non-smokers

A prospective randomized trial suggested that iron (ferritin) reduction improved outcomes in smokers. The present study reanalyzed the trial results in smokers compared with non-smokers. Randomization of 1262 men with peripheral arterial disease (540 smokers and 722 non-smokers) to iron reduction (phlebotomy) or control groups permitted analysis of the effects of iron reduction and smoking on primary (all-cause mortality) and secondary (death plus non-fatal myocardial infarction or stroke) endpoints. Iron reduction resulted in significant improvement in the primary (hazard ratio [HR] 0.661, 95% confidence interval [CI] 0.45, 0.97; P = 0.036) and secondary (HR 0.64, 95% CI 0.46, 0.88; P = 0.006) endpoints compared with controls in smokers but not in non-smokers. Smokers required removal of a greater volume of blood to attain targeted ferritin reduction as compared with non-smokers ( P = 0.003) and also exhibited differing characteristics from non-smokers, including significantly less statin use. Phlebotomy-related outcomes favored smokers over non-smokers. Biological linkages responsible for this unique effect offer promising lines for future iron reduction studies (ClinicalTrial.Gov Identifier: NCT00032357).

Iron and ADHD: time to move beyond serum ferritin levels

OBJECTIVE

(a) To compare serum ferritin levels in a sample of stimulant-naïve children with ADHD and matched controls and (b) to assess the association of serum ferritin to ADHD symptoms severity, ADHD subtypes, and IQ.

METHOD

The ADHD and the control groups included 101 and 93 children, respectively. Serum ferritin levels were determined with the enzyme-linked immunosorbent assay method.

RESULTS

Serum ferritin did not significantly differ between children with ADHD and controls, as well as among ADHD subtypes. Correlations between serum ferritin levels and measures related to IQ or ADHD severity were not significant.

CONCLUSION

This is the largest controlled study that assessed ferritin levels in stimulant-naïve ADHD children. The findings of this study do not support a significant relationship between serum ferritin levels and ADHD. However, the authors' results based on peripheral measures of iron do not rule out a possible implication of brain iron deficiency in ADHD, grounded on neurobiological hypotheses and preliminary empirical evidence.

The prevalence and impact of restless legs syndrome on patients with iron deficiency anemia

Restless Legs Syndrome (RLS) a common, under-recognized disorder disrupts sleep and diminishes quality of life. Despite a clear relation between low peripheral iron and increased prevalence and severity of RLS, the prevalence and clinical significance of RLS in iron-deficient anemic (IDA) populations is unknown. In this study all new patients referred for anemia to a community-based hematology practice over a 1-year period (March 2011-2012) were included if they had IDA and no RLS treatment. Patients completed a validated questionnaire identifying RLS, blood tests, and a sleep-vitality questionnaire (SVQ). Patients with RLS were compared to patients with no RLS for differences on SVQ, blood tests, baseline characteristics, and sleep quality. Three hundred forty-three patients were evaluated and 251 (89.2% female, average age of 45.6 years) included in the study. The prevalence of clinically significant RLS (RLS sufferers) was 23.9%, nine times higher than the general population. IDA-RLS sufferers reported poorer quality of sleep, decreased sleep time, increased tiredness, and decreased energy during the day compared to patients with IDA without RLS. Blood tests did not relate to RLS diagnosis but RLS was less likely for African-American than Caucasian patients. Clinically significant RLS occurs commonly with IDA producing much greater disruption of sleep and shorter sleep times than does IDA alone. This indicates the need for identification of RLS with IDA and consideration of appropriate therapeutic interventions for this sizeable subgroup: either aggressive iron treatment to reduce the RLS symptoms or medications for RLS or both.

Sex differences in the association between serum ferritin and fasting glucose in type 2 diabetes among South Asian Surinamese, African Surinamese, and ethnic Dutch: the population-based SUNSET study

OBJECTIVE

Moderately elevated iron stores below the levels commonly associated with hemochromatosis have been implicated in the etiology of diabetes. Studies suggest that iron status (measured by serum ferritin) differs significantly according to sex, but inconsistent findings have been reported. Our aim is to test the association between serum ferritin and the prevalence of type 2 diabetes and fasting glucose concentrations in a population-based, multiethnic, cross-sectional study including men and women of African Surinamese, South Asian Surinamese, and ethnic Dutch origin.

RESEARCH DESIGN AND METHODS

We analyzed data on 508 ethnic Dutch, 597 African Surinamese, and 339 South Asian Surinamese aged 35-60 years. Type 2 diabetes was defined as a fasting plasma glucose level ≥7.0 mmol/L or a self-reported diagnosis.

RESULTS

Serum ferritin was positively associated with type 2 diabetes and fasting glucose, but differences in the associations according to sex were observed. Serum ferritin concentration was positively associated with type 2 diabetes among women in all ethnic groups (odds ratio [OR] ethnic Dutch: 1.07 [95% CI 1.01-1.13]; OR South Asian Surinamese: 1.05 [1.00-1.10]; OR African Surinamese: 1.05 [1.01-1.10]), but not among men. Serum ferritin was also more strongly associated with fasting glucose in women than in men. Moreover, the magnitude of sex differences in the association between serum ferritin and fasting glucose, but not type 2 diabetes, was more pronounced in the African Surinamese group than in the other ethnic groups (P for interaction ≤0.0001).

CONCLUSIONS

We found a positive association between serum ferritin and type 2 diabetes and fasting glucose in our multiethnic population, which appeared stronger among women than men. Further evaluation of the variation in sex differences between ethnic groups is warranted, particularly among the African Surinamese, to understand the mechanisms behind these sex differences.

The iron status of children and youth in a community mental health clinic is lower than that of a national sample

OBJECTIVE

Iron plays a key role in brain function, and a deficiency of iron has been implicated in various cognitive, motor, and psychiatric disorders. Because of recent evidence that iron deficiency may be related to attention-deficit/hyperactivity disorder (ADHD) and other psychiatric disorders, the goal of this study was to compare the iron status of children and youth seen in a community mental health clinic with a national sample of same-aged subjects.

METHODS

In this study, a consecutive series of 108 patients (79 males) referred to a community mental health clinic was compared with a National Health and Nutrition Examination Survey (NHANES) sample on measures of iron status. Wilcoxon sign rank and median tests were used to compare distributions of ferritin. Quantile regression was performed to compare the ferritin level in the two samples while adjusting for demographic differences. Chi squared (χ2) was used to compare rates of low hemoglobin in the two samples.

RESULTS

The iron status of the clinic sample, as measured by ferritin levels (median=23 μg/L), was significantly lower than that of the national sample (median=43 μg/L). After adjustment for age, gender, and race, the clinic sample was found to have 19.2 μg/L lower ferritin than the national sample (95% CI from 7.6 to 30.9, p value=0.001). There were also significantly more subjects in the clinic sample with low hemoglobin than in the national sample. There were no differences in ferritin levels between those patients in the clinic sample with and without an ADHD or other specific psychiatric diagnosis.

CONCLUSIONS

The ferritin levels of children and youth in a mental health clinic sample were significantly lower than those of the same-aged subjects in a national sample. Therefore, compromised iron status may be an additional biological risk factor for cognitive, behavioral, and psychiatric problems in pediatric populations served by the community mental health clinic.

The statin-iron nexus: anti-inflammatory intervention for arterial disease prevention

OBJECTIVES

We postulated the existence of a statin-iron nexus by which statins improve cardiovascular disease outcomes at least partially by countering proinflammatory effects of excess iron stores.

METHODS

Using data from a clinical trial of iron (ferritin) reduction in advanced peripheral arterial disease, the Iron and Atherosclerosis Study, we compared effects of ferritin levels versus high-density lipoprotein to low-density lipoprotein ratios (both were randomization variables) on clinical outcomes in participants receiving and not receiving statins.

RESULTS

Statins increased high-density lipoprotein to low-density lipoprotein ratios and reduced ferritin levels by noninteracting mechanisms. Improved clinical outcomes were associated with lower ferritin levels but not with improved lipid status.

CONCLUSIONS

There are commonalities between the clinical benefits of statins and the maintenance of physiologic iron levels. Iron reduction may be a safe and low-cost alternative to statins.

Iron overload accelerates bone loss in healthy postmenopausal women and middle-aged men: a 3-year retrospective longitudinal study

Despite extensive experimental and animal evidence about the detrimental effects of iron and its overload on bone metabolism, there have been no clinical studies relating iron stores to bone loss, especially in nonpathologic conditions. In the present study, we performed a large longitudinal study to evaluate serum ferritin concentrations in relation to annualized changes in bone mineral density (BMD) in healthy Koreans. A total of 1729 subjects (940 postmenopausal women and 789 middle-aged men) aged 40 years or older who had undergone comprehensive routine health examinations with an average 3 years of follow-up were enrolled. BMD in proximal femur sites (ie, the total femur, femur neck, and trochanter) was measured with dual-energy X-ray absorptiometry using the same equipment at baseline and follow-up. The mean age of women and men in this study was 55.8 ± 6.0 years and 55.5 ± 7.8 years, respectively, and serum ferritin levels were significantly higher in men than in women (p < 0.001). The overall mean annualized rates of bone loss in the total femur, femur neck, and trochanter were -1.14%/year, -1.17%/year, and -1.51%/year, respectively, in women, and -0.27%/year, -0.34%/year, and -0.41%/year, respectively, in men. After adjustment for potential confounders, the rates of bone loss in all proximal femur sites in both genders were significantly accelerated in a dose-response fashion across increasing ferritin quartile categories (p for trend = 0.043 to <0.001). Consistently, compared with subjects in the lowest ferritin quartile category, those in the third and/or highest ferritin quartile category showed significantly faster bone loss in the total femur and femur neck in both genders (p = 0.023 to <0.001). In conclusion, these data provide the first clinical evidence that increased total body iron stores could be an independent risk factor for accelerated bone loss, even in healthy populations.

Increased serum ferritin concentrations and liver enzyme activities in patients with metabolic syndrome

Emerging scientific evidence suggests that increases in body iron represent a risk factor for the development of metabolic syndrome and diabetes. The aim of our study was to determine the body iron stores in patients with metabolic syndrome, and to evaluate the potential relationship of iron overload with specific features of the metabolic syndrome, such as fatty liver. A total of 490 individuals were enrolled. The diagnosis of metabolic syndrome was based on National Cholesterol Education Program-Adult Treatment Panel III (ATPIII) criteria. The metabolic syndrome group was consisted of 185 patients having three or more criteria, whereas individuals with less than three criteria constituted the control group. Metabolic syndrome patients displayed higher ferritin concentration as compared to control individuals. Ferritin levels were positively correlated with insulin concentration, as well as with Homeostasis Model Assessment (HOMA) index values. Multiple regression analysis revealed that ferritin was the most important independent determinant of insulin resistance indices. Patients with metabolic syndrome also exhibited increased concentrations of alanine aminotransferase and gamma-glutamyltranspeptidase compared to controls. Multiple regression analysis revealed that ferritin concentration was the most important determinant of gamma-glutamyltranspeptidase levels. Patients with the metabolic syndrome exhibit an increase in body iron stores as well as elevated concentrations of liver enzymes compared to the individuals who do not fulfill the criteria for the diagnosis of this syndrome. Our data support a direct role of increased body iron in the pathogenesis of insulin resistance, whereas iron overload may also contribute to the development of specific features of the metabolic syndrome, such as fatty liver.

Blood donation and colorectal cancer incidence and mortality in men

Background

Although blood donations may reduce body iron stores, to date, prospective data on frequent blood donation and colorectal cancer risk are limited.

Methodology/Principal Findings

We tested whether frequent blood donation is associated with a lower risk of colorectal cancer in the Health Professionals Follow-up Study. We prospectively followed 35,121men who provide the information on lifetime number of blood donations in 1992 through 2008. Serum ferritin levels were measured in a random sample of 305 men. Cox proportional hazard regression models were used to calculate the multivariable relative risks (RRs, 95%CIs) after adjusting for age and other established colorectal cancer risk factors. We documented 684 incident colorectal cancer cases and 224 deaths from colorectal cancer. The mean serum ferritin levels varied from 178 µg/L for men who did not donate blood to 98 µg/L for men who had at least 30 donations. Age-adjusted results for both incidence and mortality were essentially the same as the multivariable-adjusted results. Comparing with non-donors, the multivariable RRs (95%CIs) for colorectal cancer incidence were 0.92 (0.77, 1.11) for 1–5 donation, 0.85 (0.64, 1.11) for 6–9 donations, 0.96 (0.73, 1.26) for 10–19 donations, 0.91 (0.63, 1.32) for 20–29 donations, and 0.97 (0.68, 1.38) for at least 30 donations (P_trend = 0.92). The multivariable RRs for colorectal cancer mortality were 0.99 (0.72, 1.36) for 1–5 donation, 0.93 (0.57, 1.51) for 6–9 donations, 0.85 (0.50, 1.42) for 10–19 donations, and 1.14 (0.72, 1.83) for at least 20 donations (P_trend = 0.82). The results did not vary by cancer sub-sites, intake levels of total iron, heme iron, or family history of colorectal cancer.

Conclusions/Significance

Frequent blood donations were not associated with colorectal cancer incidence and mortality in men. Our results do not support an important role of body iron stores in colorectal carcinogenesis.

Back to past leeches: repeated phlebotomies and cardiovascular risk

In patients with metabolic syndrome, body iron overload exacerbates insulin resistance, impairment of glucose metabolism, endothelium dysfunction and coronary artery responses. Conversely, iron depletion is effective to ameliorate glucose metabolism and dysfunctional endothelium. Most of its effectiveness seems to occur through the amelioration of systemic and hepatic insulin resistance. In a study published by BMC Medicine, Michalsen et al. demonstrated a dramatic improvement of blood pressure, serum glucose and lipids after removing 550 to 800 ml of blood in subjects with metabolic syndrome. This effect was apparently independent of changes in insulin resistance, in contrast to previous cross-sectional and cohort studies investigating the association between iron overload, insulin resistance and cardiovascular disease. Despite drawbacks in the study design, its findings may lead the way to investigations aimed at exploring iron-dependent regulatory mechanisms of vascular tone in healthy individuals and patients with metabolic disease, thus providing a rationale for novel preventive and therapeutic strategies to counteract hypertension. Please see related article: http://www.biomedcentral.com/1741-7015/10/54.

The neglected significance of "antioxidative stress"

Oxidative stress arises when there is a marked imbalance between the production and removal of reactive oxygen species (ROS) in favor of the prooxidant balance, leading to potential oxidative damage. ROSs were considered traditionally to be only a toxic byproduct of aerobic metabolism. However, recently, it has become apparent that ROS might control many different physiological processes such as induction of stress response, pathogen defense, and systemic signaling. Thus, the imbalance of the increased antioxidant potential, the so-called antioxidative stress, should be as dangerous as well. Here, we synthesize increasing evidence on “antioxidative stress-induced” beneficial versus harmful roles on health, disease, and aging processes. Oxidative stress is not necessarily an un-wanted situation, since its consequences may be beneficial for many physiological reactions in cells. On the other hand, there are potentially harmful effects of “antioxidative stress,” especially in the cases of overconsumption of synthetic antioxidants. Antioxidants can neutralize ROS and decrease oxidative stress; however, this is not always beneficial in regard to disease formation or progression (of, e.g., cancer) or for delaying aging.

Hepcidin expression in patients with acute leukaemia

BACKGROUND

Hepcidin plays a central role in iron homeostasis, which is regulated by iron stores, the rate of erythropoiesis, inflammation, and hypoxia. Aberrant expression of hepcidin was found in many diseases, however, there is scant information on hepcidin expression in acute leukemia (AL).

MATERIALS AND METHODS

32 patients with AL which diagnosis according to FAB criteria were studied. Serum hepcidin levels, erythropoietin (EPO), interleukin-6 (IL-6), hematological parameters, intracellular and extracellular iron store were evaluated.

RESULTS

Hepcidin was elevated significantly with increased iron storage in patients at onset of AL when erythropoiesis was depressed by blast cells, then decreased significantly with AL remission, while soluble transferrin receptor (sTfR) concentration was elevated. Negative correlations were found between serum hepcidin and erythropoietic markers including RBC, Hb, Ret and sTfR. Positive correlations were shown between hepcidin and ferritin, between hepcidin and ratio of sideroblasts, as well as between hepcidin and IL-6.

CONCLUSIONS

Hepcidin production was regulated by iron stores, inflammation and erythropoietic activity in AL patients. Erythropoietic activity may play the main role among the regulators of hepcidin expresssion.

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.

Circulating biomarkers of iron storage and clearance of incident human papillomavirus infection

BACKGROUND

Iron is an essential mineral for both cellular and pathogen survival and is essential for viral replication. In turn, iron metabolism has been shown to be altered by several viral infections. However, little is known about the association between iron status and human papillomavirus (HPV) natural history. We hypothesize iron to be an HPV cofactor that is associated with longer duration of infection.

METHODS

Ferritin and soluble transferrin receptor (sTfR) were measured in baseline serum samples from 327 women enrolled in the Ludwig-McGill cohort. Incident HPV clearance rates (any-type, oncogenic HPV, nononcogenic HPV, and HPV-16) over a 3 year time period were estimated from Cox proportional hazard models accounting for correlations between multiple infections.

RESULTS

Women with ferritin levels above the median were less likely to clear incident oncogenic HPV [adjusted hazard ratio (AHR), 0.73; 95% confidence interval (CI), 0.55-0.96] and HPV-16 infections (AHR, 0.29; 95% CI, 0.11-0.73). Using physiologic cutoff points, women with enriched iron stores (>120 μg/L) were less likely to clear incident oncogenic HPV infections than those with low levels of iron (<20 μg/L; AHR, 0.34; 95% CI, 0.15-0.81).

CONCLUSION

This study observed that women with the highest ferritin levels were less likely to clear incident oncogenic and HPV-16 infections than women with low ferritin. Rising iron stores may decrease probability of clearing new HPV infection, possibly by promoting viral activity and contributing to oxidative DNA damage.

IMPACT

This novel study suggests that elevated iron stores may put women at risk for persistent HPV infection, an early event in cervical carcinogenesis. Further examination of the association between iron status and HPV natural history is warranted.

Serum ferritin levels are associated with metabolic syndrome in postmenopausal women but not in premenopausal women

OBJECTIVE

Ferritin, a marker of total body iron stores, is known to be associated with the risk of having metabolic syndrome and has been demonstrated to increase after the onset of menopause. Postmenopause status is an important determinant of metabolic syndrome. The aim of this study was to perform a menopause status-specific analysis of the association between ferritin levels and metabolic syndrome.

METHODS

We conducted a cross-sectional study of 3,082 participants (1,691 premenopausal women and 1,391 postmenopausal women), all of whom were enrolled in the Korean National Health and Nutrition Examination Survey 2007.

RESULTS

Premenopausal and postmenopausal women with metabolic syndrome had higher ferritin levels than did those without metabolic syndrome. After adjustments for age; body mass index; alcohol intake; smoking history; exercise; hormone therapy use; hemoglobin, aspartate aminotransferase, and alanine aminotransferase levels; and intake of energy and iron, multivariate logistic regression analysis revealed that postmenopausal women with ferritin levels in the third tertile had an increased risk of having metabolic syndrome (odds ratio, 1.62; 95% CI, 1.04-2.81) compared with postmenopausal women with levels in the first quartile. No such association was detected in premenopausal women.

CONCLUSIONS

Increased ferritin levels may be a determinant for metabolic syndrome in postmenopausal women but not in premenopausal women.

Serum ferritin levels associated with increased risk for developing CHD in a low-income urban population

OBJECTIVE

The present study examined the association of serum ferritin with CHD risk using the Framingham Heart Study's 10-year risk algorithm.

DESIGN

Ordinal logistic regression modelling was used to interpret risk. Proportional odds modelling assessed four divisions of ranked CHD risk (4, high; 3, increased; 2, slight; 1, minimal), separately by sex.

SETTING

Baltimore, MD, USA.

SUBJECTS

African-American and white participants (n 1823) from baseline of the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study, aged 30-64 years.

RESULTS

For men, there was a 0·5 % increase in risk for every 10-unit rise in serum ferritin (pmol/l). Other significant predictors included increased BMI, white race, unemployment and C-reactive protein ≥9·5 mg/l. For women, there was a 1·5 % [corrected] increase in risk per 10-unit rise in serum ferritin (pmol/l). Other significant predictors included increased BMI, lower education, unemployment and C-reactive protein ≥9·5 mg/l.

CONCLUSIONS

Serum ferritin is a significant predictor of 10-year hard CHD risk for HANDLS study participants, a low-income, urban population. Serum ferritin, independent of elevated C-reactive protein, was associated with increased 10-year CHD risk for HANDLS participants. To our knowledge, these data provide the first evidence of the role of serum ferritin as a risk factor for hard CHD in African-American and white postmenopausal women in the USA. Future research on cardiovascular events from this prospective study may confirm the association.

Racial differences in restless legs symptoms and serum ferritin in an incident dialysis patient cohort

PURPOSE

Restless legs syndrome (RLS), a debilitating sleep disorder that is frequently reported by CKD patients on dialysis, may be more common in whites than in non-whites. Iron deficiency is associated with RLS, and serum ferritin is higher among African Americans compared to Caucasians in the general population. No prior studies have compared restless legs symptoms and serum ferritin levels of African-American and those of the Caucasian patients on dialysis.

METHODS

In a multicenter observational study that included in-person interviews and medical chart review, we studied 210 patients who had recently started renal dialysis. Predictors of restless legs symptoms were examined in a multivariable logistic regression model.

RESULTS

African Americans had a reduced risk of restless legs complaint compared to Caucasian patients (OR, 0.44 [95% CI 0.21-0.93]; P=0.03). African-American patients were also less likely than Caucasian patients to have low serum ferritin values (<100 ng/ml), and among patients with serum ferritin≥100 ng/ml, the average serum ferritin of African-American patients was higher than that of Caucasian patients.

CONCLUSIONS

Further study of racial and iron status relationships could advance the understanding of RLS pathophysiology, and RLS is an important patient outcome to monitor, as revised anemia and iron protocols are implemented in the clinical setting.

Iron overload: what is the role of public health?

Hereditary hemochromatosis type 1, also known as hereditary hemochromatosis classical (HHC), is an iron overload disorder associated, in most cases, with mutations of the hemochromatosis (HFE) gene. Although suggested algorithms for diagnosing iron overload are available, there are still questions about options for genetic and biochemical screening for hemochromatosis and duration of treatment. This article provides a summary of an expert workgroup meeting convened on September 24-25, 2009, entitled "Iron Overload: What is the Role of Public Health?" The purpose of the meeting was to enable subject matter experts to share their most recent clinical and scientific iron overload information and to facilitate the discussion of future endeavors, with special emphasis on the role of public health in this field. The two main topics were the research priorities of the field, including clinical, genetic, and public health issues, and the concerns about the validity of current screening recommendations for the condition.

Study of the effect of iron overload on the function of endocrine glands in male thalassemia patients

Background:

Iron overload is an important issue in the state of thalassemic patients due to the harmful effect of high concentration of iron deposited in different tissues in human body including endocrine glands. In the present work, an attempt is carried out to estimate the effect of iron overload in thalassemic patients on the function of endocrine glands through the estimation of their ability to secrete adequate amounts of certain hormones.

Materials and Methods:

Seventy eight male children with beta-thalassemia, in the age-group of 4–11 years, were enrolled for this research. These children were being treated with frequent transfusions and long-term iron chelation therapy. Thirty age and sex matched children without thalassemia constituted the control group. Ferritin and different hormones were estimated by ELISA technique.

Results:

The results showed a mild reduction in the function of endocrine glands through the decrease in the level of some hormones. These changes due mainly to the hypoxia and precipitation of iron in certain glands and overlapping with the synthesis or secretion of the hormones.

Conclusion:

There is a different hormonal disturbances in beta thalassemia patients. Reduction of total body iron store is an important goal of the treatment of thalassemia and measuring the hormones concentration is necessary for the follow up of the thalassemic patients especially during puberty.

Effect of controlled reduction of body iron stores on clinical outcomes in peripheral arterial disease

BACKGROUND

Published results from a controlled clinical trial in patients with peripheral arterial disease found improved outcomes with iron (ferritin) reduction among middle-aged subjects but not the entire cohort. The mechanism of the age-specific effect was explored.

METHODS

Randomization to iron reduction (phlebotomy, n = 636) or control (n = 641) stratified by prognostic variables permitted analysis of effects of age and ferritin on primary (all-cause mortality) and secondary (death, nonfatal myocardial infarction, and stroke) outcomes.

RESULTS

Iron reduction improved outcomes in youngest age quartile patients (primary outcome hazard ratio [HR] 0.44, 95% CI 0.21-0.92, P = .028; secondary outcome HR 0.34, 95% CI 0.19-0.61, P < .001). Mean follow-up ferritin levels (MFFL) declined with increasing entry age in controls. Older age (P = .035) and higher ferritin (P < .001) at entry predicted poorer compliance with phlebotomy and rising MFFL in iron-reduction patients. Intervention produced greater ferritin reduction in younger patients. Improved outcomes with lower MFFL were found in iron-reduction patients (primary outcome HR 1.11, 95% CI 1.01-1.23, P = .028; secondary outcome HR 1.10, 95% CI 1.0-1.20, P = .044) and the entire cohort (primary outcome HR 1.11, 95% CI 1.01-1.23, P = .037). Improved outcomes occurred with MFFL below versus above the median of the entire cohort means (primary outcome HR 1.48, 95% CI 1.14-1.92, P = .003; secondary outcome HR 1.22, 95% CI 0.99-1.50, P = .067).

CONCLUSIONS

Lower iron burden predicted improved outcomes overall and was enhanced by phlebotomy. Controlling iron burden may improve survival and prevent or delay nonfatal myocardial infarction and stroke.

Association of serum ferritin with metabolic syndrome and diabetes mellitus in the South Korean general population according to the Korean National Health and Nutrition Examination Survey 2008

We examined the association of serum ferritin levels with metabolic syndrome (MS) and diabetes mellitus in a representative sample of the adult South Korean population using data from the 2008 Korean National Health and Nutrition Examination Survey. We conducted a cross-sectional study of 6311 adults older than 20 years who participated in the 2008 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined as the presence of at least 3 of the following: elevated blood pressure, low high-density lipoprotein cholesterol, elevated serum triglycerides, elevated plasma glucose, and abdominal obesity. Diabetes mellitus was defined as fasting glucose of at least 126 mg/dL. Insulin resistance was determined using the homeostasis model assessment estimate of insulin resistance. In a representative sample of the adult Korean population, MS was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in women following adjustments for age, education, smoking, alcohol intake, body mass index, aspartate aminotransferase, and alanine aminotransferase. Diabetes mellitus was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in premenopausal women and men. The geometric means of fasting insulin and insulin resistance determined using the homeostasis model assessment of insulin resistance in the fourth serum ferritin quartiles of postmenopausal women and men were significantly higher compared with those in the first quartile of the respective groups. The present study demonstrates that elevated serum ferritin concentrations are associated with an increased risk of MS and diabetes mellitus in a representative sample of the adult South Korean population.

Hemochromatosis and ovarian cancer

Evaluation of: Gannon PO, Medelci S, Le Page C et al. Impact of hemochromatosis gene (HFE) mutations on epithelial ovarian cancer risk and prognosis. Int. J. Cancer 128(10), 2326-2334 (2011). The frequency of two mutations (C282Y and D62H) of the hemochromatosis gene were investigated in women with ovarian cancer. A single allele mutation of the C282Y but not the H63D gene product was detected in 8-9% of women with benign ovarian tumors (n = 124) and ovarian cancers (n = 360) compared with 2.5% for controls (n = 80) representing a 4.9-fold increase in risk. With high-grade serous ovarian cancers (n = 179), the survival rate of women with a single allele C282Y mutation was reduced from 39 to 19 months. These results implicate mutations of the hemochromatosis gene in the generation and severity of ovarian cancers, which may have prognostic value.

The relationship between serum ferritin and metabolic syndrome in healthy Korean men

BACKGROUND AND OBJECTIVE

Elevated serum ferritin levels have been reported to be associated with several metabolic disorders. We investigated the relationship between serum ferritin level and metabolic syndrome and its components in healthy Korean men.

METHODS

In this cross-sectional study, serum ferritin level and metabolic syndrome and its components were measured from 18 581 men from January to December in 2008. The presence of metabolic syndrome was determined according to the most recent consensus report of the National Cholesterol Education Program's Third Adult Treatment Panel. Logistic regression models were applied to examine the relationship between the serum ferritin level and the metabolic syndrome and its components.

RESULTS

After adjusting for clinical covariates, the odds ratio and 95% confidence intervals of metabolic syndrome with respect to Q2, Q3 and Q4 were 1.34 (1.14-1.57), 1.49 (1.24-1.70) and 1.99 (1.70-2.33), respectively (p for trend < 0.001). The multivariable-adjusted model also showed a significantly graded relationship between individual components of metabolic syndrome and the quartile groups of serum ferritin.

CONCLUSIONS

In this study, elevated ferritin concentration is independently associated with metabolic syndrome and its components among healthy Korean men.

Age-associated variation in sensory perception of iron in drinking water and the potential for overexposure in the human population

Humans interact with their environment through the five senses, but little is known about population variability in the ability to assess contaminants. Sensory thresholds and biochemical indicators of metallic flavor perception in humans were evaluated for ferrous (Fe(2+)) iron in drinking water; subjects aged 19-84 years participated. Metallic flavor thresholds for individuals and subpopulations based on age were determined. Oral lipid oxidation and oral pH were measured in saliva as potential biochemical indicators. Individual thresholds were 0.007-14.14 mg/L Fe(2+) and the overall population threshold was 0.17 mg/L Fe(2+) in reagent water. Average thresholds for individuals younger and older than 50 years of age (grouped by the daily recommended nutritional guidelines for iron intake) were significantly different (p = 0.013); the population thresholds for each group were 0.045 mg/L Fe(2+) and 0.498 mg/L Fe(2+), respectively. Many subjects >50 and a few subjects <50 years were insensitive to metallic flavor. There was no correlation between age, oral lipid oxidation, and oral pH. Standardized olfactory assessment found poor sensitivity for Fe(2+) corresponded with conditions of mild, moderate, and total anosmia. The findings demonstrate an age-dependent sensitivity to iron indicating as people age they are less sensitive to metallic perception.

Iron sensitizes keratinocytes and fibroblasts to UVA-mediated matrix metalloproteinase-1 through TNF-α and ERK activation

Oestrogen deficiency is regarded as the main causative factor in postmenopausal skin ageing and photoageing. While women after menopause experience low levels of oestrogen because of cease of ovarian function, they are also exposed to high levels of iron as a result of cessation of menstruation. In this study, we investigated whether this increase in iron presents a risk to the postmenopausal skin. Because of the lack of appropriate animal models to closely mimic the low oestrogen and high iron conditions, we tested the hypothesis in a high iron and low oestrogen culture model. Here, we showed that primary human dermal fibroblasts exposed to iron did not affect the baseline levels of matrix metalloproteinase-1 (MMP-1) activity. However, the iron-exposed fibroblasts were sensitized to UVA exposure, which resulted in a synergistic increase in MMP-1. UVA activated the three members of MAPK family: ERKs, p38, and JNKs. Additional activation of ERKs by iron contributed to the synergistic increases. Primary normal human epidermal keratinocytes (NHEK) did not respond to iron or UVA exposure as measured by MMP-1, but produced tumor necrosis factor-alpha (TNF-α) in the media, which then stimulated MMP-1 in fibroblasts. Our results indicate that iron and UVA increase MMP-1 activity in dermal fibroblasts not only directly through ERK activation but also by an indirect paracrine loop through TNF-α released by NHEK. We conclude that in addition to oestrogen deficiency, increased iron as a result of menopause could be a novel risk factor by sensitizing postmenopausal skin to solar irradiation.

Hepcidin expression and iron parameters change in Type 2 diabetic patients

AIM

Iron may contribute to the pathogenesis of Type 2 diabetes mellitus (DM). The aim of this study was to determine iron regulator hepcidin and iron metabolic parameters in Type 2 DM patients, the relationships among them were evaluated in this specific sub-groups.

MATERIALS AND METHODS

The study included sixty-four people: 34 cases of diabetes and 30 age-matched controls. Serum hepcidin, IL-6, hsCRP, ferritin, sTfR, EPO as well as other clinical parameters were detected, and the associations between hepcidin levels and iron/inflammatory parameters were analyzed in diabetes and the controls.

RESULTS

Serum ferritin and hepcidin levels in diabetic patients were significant higher than the controls (p<0.001 respectively). A positive correlation between hepcidin and ferritin, as well as between ferritin and IL-6 levels was existed in diabetes and the control groups (p<0.001 respectively).

CONCLUSION

All of these data demonstrated that the higher hepcidin levels in diabetic patients may be due to those higher ferritin and IL-6 levels, the elevated hepcidin might have adaptive value through down-regulated iron absorb and play an important role in pathogenesis of Type 2 DM.

The relationship between body iron stores and blood and urine cadmium concentrations in US never-smoking, non-pregnant women aged 20-49 years

BACKGROUND

Cadmium is a ubiquitous environmental pollutant associated with increased risk of leading causes of mortality and morbidity in women, including breast cancer and osteoporosis. Iron deficiency increases absorption of dietary cadmium, rendering women, who tend to have lower iron stores than men, more susceptible to cadmium uptake. We used body iron, a measure that incorporates both serum ferritin and soluble transferrin receptor, as recommended by the World Health Organization, to evaluate the relationships between iron status and urine and blood cadmium.

METHODS

Serum ferritin, soluble transferrin receptor, urine and blood cadmium values in never-smoking, non-pregnant, non-lactating, non-menopausal women aged 20-49 years (n=599) were obtained from the 2003-2008 National Health and Nutrition Examination Surveys. Body iron was calculated from serum ferritin and soluble transferrin receptor, and iron deficiency defined as body iron <0 mg/kg. Robust linear regression was used to evaluate the relationships between body iron and blood and urine cadmium, adjusted for age, race, poverty, body mass index, and parity.

RESULTS

Per incremental (mg/kg) increase in body iron, urine cadmium decreased by 0.003 μg/g creatinine and blood cadmium decreased by 0.014 μg/L. Iron deficiency was associated with 0.044 μg/g creatinine greater urine cadmium (95% CI=0.020, 0.069) and 0.162 μg/L greater blood cadmium (95% CI=0.132, 0.193).

CONCLUSIONS

Iron deficiency is a risk factor for increased blood and urine cadmium among never-smoking, pre-menopausal, non-pregnant US women, independent of age, race, poverty, body mass index and parity. Expanding programs to detect and correct iron deficiency among non-pregnant women merits consideration as a potential means to reduce the risk of cadmium associated diseases.

The role of iron in tumour cell proliferation

Iron has a pivotal role in homeostasis due to its participation in virtually all of the body's oxidation-reduction processes. However, iron can also be considered a double-edged weapon, as its excess may lead to an increased risk of developing cancer, presumably by the generation of reactive oxygen species, and its role as substrate to enzymes that participate in cell proliferation. Thus, iron might as well be considered a cofactor in tumour cell proliferation. In certain pathological conditions, such as haemochromatosis, hepatitis B and C virus infection, asbestosis and endometriosis, iron overload may increase the risk of cancer. By contrast, iron depletion could be considered a useful adjunct in antitumour therapy. This paper reviews the current scientific evidence behind iron's role as a protumoral agent, and the potential benefit of a state of iron depletion in patients with cancer.

Iron as a target of chemoprevention for longevity in humans

Iron is universally abundant and no life can exist without it. However, iron levels should be maintained within a narrow range. Iron deficiency causes anaemia, whereas excessive iron increases cancer risk, presumably by free radical generation. Several pathological conditions such as genetic haemochromatosis, chronic viral hepatitis B and C, conditions related to asbestos fibre exposure and ovarian endometriosis have been recognized as iron overload-associated conditions that also increase human cancer risks. Iron's carcinogenicity has been documented in animal experiments. Surprisingly, these studies have revealed that the homozygous deletion of CDKN2A/2B is a major hallmark of iron-induced carcinogenesis. Recently, the hormonal regulation of iron metabolism has been elucidated. A commonly hypothesized mechanism may be the lack of any iron disposal pathway other than for bleeding and a mechanism of iron re-uptake as catechol chelate has been discovered. Iron overload in neurons via the ferroportin block may play a role in Alzheimer's disease. Furthermore, a recent epidemiological study reported that iron reduction by phlebotomy was associated with decreased cancer risks in a general population. Given that the required amounts of iron decrease during ageing, the fine control of body iron stores would be a wise strategy for chemoprevention of several diseases.

Impact of hemochromatosis gene (HFE) mutations on epithelial ovarian cancer risk and prognosis

Cancer cells require large amounts of micronutrients, particularly iron, for their rapid growth and frequent divisions. Cellular iron uptake is regulated by the transferrin receptor and the hemochromatosis protein (HFE) system. Two frequent mutations in the HFE gene, H63D and C282Y, are associated with hemochromatosis type I, an inherited iron overload disease and, possibly, with cancer. In this study, we evaluated the frequency of the H63D and C282Y mutations in a cohort of 677 consecutive cases of woman with gynecological pathologies. Cases included 80 women with tumor-free pathologies normal ovary (NOV), 124 with benign ovarian tumors (BOV), 96 with epithelial ovarian cancer (EOC) tumors of low malignant potential (LPM), 264 with invasive tumors of the ovary (TOV) and 113 with endometrial cancer. We found that the C282Y allele frequency in EOC patients was higher than that in the control NOV group (5.8% vs. 1.3%, p < 0.001) and was associated with an increased risk of ovarian cancer (OR = 4.88; 95% CI 1.15-20.61; p = 0.018). The effect of the two HFE mutations on patient survival was also analyzed. Kaplan-Meier analyses did not find any significant association between the H63D allele and patient survival. However, EOC patients with at least one C282Y allele had a decreased overall survival compared to those with no C282Y allele (p = 0.001). These results indicate that the C282Y mutation may increase the risk of developing ovarian cancer and may be further associated with poor outcomes.

Mysterious link between iron overload and CDKN2A/2B

Persistent oxidative stress has been associated with carcinogenesis. Iron overload is considered one such condition that causes oxidative stress. Epidemiological studies support a close link between iron overload and carcinogenesis. Reportedly, regular semiannual phlebotomies reduced cancer risk in an otherwise normal population. More specifically, genetic hemochromatosis, chronic viral hepatitis, ovarian endometriosis and asbestosis induce iron overload, which can lead to hepatocellular carcinoma, ovarian carcinoma or mesothelioma in humans. Through a combination of animal experiments and microarray analyses, homozygous deletion of CDKN2A/2B has been recognized as one of the major target genes involved in iron overload-induced carcinogenesis. CDKN2A/2B are the second most frequently inactivated tumor suppressing genes in human cancers. Currently, when infection is becoming sufficiently controlled worldwide, iron regulation may be the next target for human longevity.

The emerging role of iron dyshomeostasis in the mitochondrial decay of aging

Recent studies show that cellular and mitochondrial iron increases with age. Iron overload, especially in mitochondria, increases the availability of redox-active iron, which may be a causal factor in the extensive age-related biomolecular oxidative damage observed in aged organisms. Such damage is thought to play a major role in the pathogenesis of iron overload diseases and age-related pathologies. Indeed, recent findings of the beneficial effects of iron manipulation in life extension in Caenorhabditis elegans, Drosophila and transgenic mice have sparked a renewed interest in the potential role of iron in longevity. A substantial research effort now focuses on developing and testing safe pharmacologic interventions to combat iron dyshomeostasis in aging, acute injuries and in iron overload disorders.

Iron status is associated with carotid atherosclerotic plaques in middle-aged adults

Although the iron-heart disease hypothesis is prevalent, the epidemiological findings are incongruent. The relationship of serum ferritin with early cardiovascular disease (CVD), particularly atherosclerosis, has not been evaluated extensively, particularly with accounting for inflammation. We examined this association in a case-control study of 124 age- and sex-matched pairs embedded in the population-based random sample (MONICA survey) in Southwest France, taking into account inflammation status. Cases had >or=2 carotid atherosclerotic plaques and controls had none. Inflammation was assessed using several markers, including serum alpha-1 acid glycoprotein (AGP) and high sensitivity C-reactive protein. There was an interaction of inflammation with group (case/control) for serum ferritin. In adults without elevated AGP, serum ferritin was significantly greater in atherosclerotic cases than in adults in the control group. In models adjusted for CVD risk factors, the odds of atherosclerosis increased with the increase in serum ferritin in individuals without elevated AGP; for every 10-microg/L increase in serum ferritin, the risk for atherosclerosis increased by 3% (odds ratio [95% CI]: 1.03 [1.01-1.06]). In conclusion, carotid atherosclerosis was positively associated with serum ferritin in individuals free from subclinical inflammation based on AGP. Further prospective and/or experimental studies are needed to corroborate the observed association of iron status with atherosclerosis.

Ferritin levels, inflammatory biomarkers, and mortality in peripheral arterial disease: a substudy of the Iron (Fe) and Atherosclerosis Study (FeAST) Trial

BACKGROUND

This study delineated correlations between ferritin, inflammatory biomarkers, and mortality in a cohort of 100 cancer-free patients with peripheral arterial disease (PAD) participating in the Veterans Affairs (VA) Cooperative Study #410, the Iron (Fe) and Atherosclerosis Study (FeAST). FeAST, a prospective, randomized, single-blind clinical trial, tested the hypothesis that reduction of iron stores using phlebotomy would influence clinical outcomes in 1227 PAD patients randomized to iron reduction or control groups. The effects of statin administration were also examined in the Sierra Nevada Health Care (SNHC) cohort by measuring serum ferritin levels at entry and during the 6-year study period. No difference was documented between treatment groups in all-cause mortality and secondary outcomes of death plus nonfatal myocardial infarction and stroke. Iron reduction in the main study caused a significant age-related improvement in cardiovascular disease outcomes, new cancer diagnoses, and cancer-specific death.

METHODS

Tumor necrosis factor (TNF)-alpha, TNF-alpha receptors 1 and 2, interleukin (IL)-2, IL-6, IL-10, and high-sensitivity C reactive protein (hs-CRP) were measured at entry and at 6-month intervals for 6 years. Average levels of ferritin and lipids at entry and at the end of the study were compared. The clinical course and ferritin levels of 23 participants who died during the study were reviewed.

RESULTS

At entry, mean age of entry was 67 +/- 9 years for the SNHCS cohort, comparable to FeAST and clinical and laboratory parameters were equivalent in substudy participants randomized to iron reduction (n = 51) or control (n = 49). At baseline, 53 participants on statins had slightly lower mean entry-level ferritin values (114.06 ng/mL; 95% confidence interval [CI] 93.43-134.69) vs the 47 off statins (127.62 ng/mL; 95% CI, 103.21-152.02). Longitudinal analysis of follow-up data, after adjusting for the phlebotomy treatment effect, showed that statin use was associated with significantly lower ferritin levels (-29.78 ng/mL; Cohen effect size, -0.47 [t(df, 134) = 2.33, P = .02]). Mean follow-up average ferritin levels were higher in 23 participants who died (132.5 ng/mL; 95% CI, 79.36-185.66) vs 77 survivors (83.6 ng/mL; 95% CI, 70.34-96.90; Wilcoxon P = .05). Mean follow-up IL-6 levels were higher in dead participants (21.68 ng/mL; 95% CI, 13.71-29.66) vs survivors (12.61 ng/mL; 95% CI, 10.72-14.50; Wilcoxon P = .018). Ferritin levels correlated (Pearson) with average IL-6 levels (r = 0.1845; P = .002) and hsCRP levels (r = .1175; P = .04) during the study.

CONCLUSION

These data demonstrate statistical correlations between levels of ferritin, inflammatory biomarkers, and mortality in this subset of patients with PAD.

Remission of paroxysmal atrial fibrillation with iron reduction in haemophilia A

SUMMARY

Two male first cousins with mild haemophilia A had baseline factor VIII levels of 12-15% and experienced bleeding requiring coagulation factor infusion therapy with trauma and surgical procedures. Both the patients with haemophilia A also had electrocardiographically documented symptomatic paroxysmal atrial fibrillation (PAF) for several years that had become resistant to pharmacological suppression. Radiofrequency ablation was considered in both the cases but deferred considering refusal of consent by the patients to undergo the procedure. Remission of arrhythmias has been reported in patients with iron-overload syndromes. Body iron stores assessed by serum ferritin levels were elevated in both men but neither had the C282Y or H63D genes for haemochromatosis. Calibrated reduction of iron stores by serial phlebotomy, avoiding iron deficiency, was followed by remission of symptomatic PAF in both cases. Iron reduction may be an effective treatment for arrhythmias apart from the classic iron-overload syndromes and deserves further study particularly in patients with bleeding disorders who might be at risk for arrhythmias and other diseases of ageing.