The relationship between indices of iron status and selected anthropometric cardiovascular disease risk markers in an African population: the THUSA study

Effects of body compositions on the associations between ferritin and diabetes parameters among Japanese community dwellers

BACKGROUND

Ferritin is associated with an increased prevalence of diabetes mellitus. Moreover, the ferritin levels differ across the body compositions. Although there were studies reporting the association of ferritin and diabetes, the alteration in ferritin-diabetes association by body composition differences is rarely explained. Thus, the aim of this study is to identify the effects of body compositions on the association between ferritin and diabetes parameters among the Japanese population.

METHODS

This study analyzed the data of a cross-sectional study with 1065 subjects aged over 19 years in the Iwaki area, Japan. Independent variables were ferritin and body compositions, while dependent variables were blood sugar, HbA1c, and diabetes mellitus. Correlations between serum ferritin and blood sugar and HbA1c were analyzed using Spearman's Rank Correlation. Multivariate linear or logistic regressions were used to investigate the effects of body compositions (body fat percentage, muscle mass, or visceral fat level) on the ferritin-diabetes associations by adjusting the confounders.

RESULTS

There were significant positive correlations between ferritin and blood sugar in both sexes (p < 0.05), while a significant correlation between ferritin and HbA1c was found only in females (p < 0.001). Higher ferritin was significantly associated with an increase in blood sugar in individuals with normal body fat percentage (lowest vs. highest quartile group, coefficient=5.07, 95 % confidence intervals [CI]: 1.48-8.65), normal visceral fat level (lowest vs. highest quartile group, coefficient=4.84, 95 % CI: 1.74-7.94), and very high muscle mass (lowest vs. highest quartile group, coefficient=14.14, 95 % CI: 5.00-23.29).

CONCLUSIONS

By our study findings, individuals' body composition notably influenced the associations of serum ferritin and diabetes parameters, and the association was attenuated in obese individuals.

Plasma Ferritin Concentrations in the General Population: A Cross-Sectional Analysis of Anthropometric, Metabolic, and Dietary Correlates

BACKGROUND

Elevated concentrations of ferritin seem to be detrimental to human health while being quite common in the elderly. Data on dietary, anthropometric, and metabolic correlates of circulating ferritin levels in the elderly are scant.

OBJECTIVES

We aimed to identify a dietary pattern, anthropometric, and metabolic traits associated with plasma ferritin status in an elderly cohort (n = 460, 57% male, age: 66 ± 12 y) from Northern Germany.

METHODS

Plasma ferritin levels were measured by immunoturbidimetry. Reduced rank regression (RRR) yielded a dietary pattern explaining 13% of the variation in circulating ferritin concentrations. Cross-sectional associations of anthropometric and metabolic traits with plasma ferritin concentrations were assessed using multivariable-adjusted linear regression analysis. Restricted cubic spline regression was used to identify nonlinear associations.

RESULTS

The RRR pattern was characterized by a high intake of potatoes, certain vegetables, beef, pork, processed meat, fats (frying and animal fat), and beer and a low intake of snacks, representing elements of the traditional German diet. BMI, waist circumference, and CRP were directly, HDL cholesterol inversely, and age nonlinearly associated with plasma ferritin concentrations (all P < 0.05). After additional adjustment for CRP, only the association of ferritin with age remained statistically significant.

CONCLUSION

Higher plasma ferritin concentrations were associated with a traditional German dietary pattern. The associations of ferritin with unfavorable anthropometric traits and low HDL cholesterol were rendered statistically nonsignificant upon additional adjustment for chronic systemic inflammation (CRP), suggesting that these associations were largely driven by the proinflammatory role of ferritin (an acute-phase reactant). J Nutr 20xx;x:xx.

The relationship between plasma ferritin levels and body mass index among adolescents

Circulatory Ferritin concentration varies with age, sex, and body composition. Studies that determine the relationship of different body weight measurements with plasma ferritin concentration in adolescents are lacking. A descriptive cross-sectional design was utilized. Data collection involved self-reporting demographics, blood samples, and body composition measures for a sample of 814 healthy Jordanian adolescents. Ferritin deficiency was observed in 55.8% of the study population. Simple linear regression showed that BMI, gender, location, and smoking status 2.5%, 3.9%, 0.4%, and 0.4%, respectively, associated positively with plasma ferritin level (p < 0.05). After controlling for gender, location, and smoking status, additional hierarchal multiple linear regression showed that BMI explained 2.2% of plasma ferritin (p < 0.000). However, the obesity-stratified hierarchal multiple linear regression, showed that BMI explained 2.1% of plasma ferritin in the overweight and obese (HI) adolescents (p = 0.02), but not in the under and normal weight (LO) adolescents (p = 0.91). After controlling for gender, location, and smoking status, the ANCOVA showed that plasma ferritin level was greater (p < 0.000) in the HI (19.00 ± 13.6) versus the LO (15.20 ± 10.4) obesity group. Our results indicated that normal ferritin level among obese people does not necessarily indicate normal iron storage.

Conflicting effects of BMI and waist circumference on iron status

The association between obesity and iron status has a long history and is still receiving attention. However comparative analysis of the association between general obesity (BMI) and visceral obesity (waist circumference) with iron status has not been extensively researched. The aim of the present study is thus to determine if body mass index and waist circumference have the same correlation with iron status. One thousand one hundred and thirty people (225 men and 905 women) aged 30 years and above participated in this study. Anthropometric parameters, haemoglobin, iron and total iron binding capacity concentrations were measured using standard methods. Percentage transferrin saturation was calculated and ferritin concentrations were measured using an enzyme linked immunosorbent assay. Obese or overweight women had significantly lower iron and transferrin saturation concentration when compared to non-obese women. In contrast, women with high waist circumference had comparable plasma iron and transferrin saturation to women with normal waist circumference. Partial correlation analysis and linear regression analysis showed that BMI is negatively and significantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration, whilst waist circumference is positively but insignificantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration. Binary regression analysis showed that obese or overweight people are more likely to have iron deficiency, whilst those with raised waist circumference are more likely to have iron overload. Multivariate analysis showed that body mass index is negatively and significantly associated with low iron status, while waist circumference is positively and insignificantly associated with iron status. This is supported by a comparison of plasma iron, transferrin saturation and ferritin concentrations in participants with high body mass index and normal waist circumference and participants with normal body mass index and high waist circumference to those participants having normal body mass index and normal waist circumference. The present study suggests that in women body mass index is associated with low plasma iron, transferrin saturation and ferritin concentrations, while waist circumference is associated with high plasma iron, transferrin saturation and ferritin concentrations.

Common Variants and Haplotypes in the TF, TNF-α, and TMPRSS6 Genes Are Associated with Iron Status in a Female Black South African Population

BACKGROUND

It is unknown whether single nucleotide polymorphisms (SNPs), associated with iron status in European and Asian populations, have the same relation within the African population.

OBJECTIVES

We investigated associations of reported SNPs with iron markers in a South African cohort.

METHODS

Hemoglobin concentration, serum ferritin (SF) and soluble transferrin receptor (sTfR) concentrations, and body iron (BI) stores were measured in women (n = 686; range, 32-86 y) who were part of the Prospective Urban and Rural Epidemiology study. Thirty-two SNPs in 12 genes were selected based on existing genome-wide association study data.

RESULTS

In the transferrin (TF) gene, SF and BI were significantly lower in the heterozygote genotype (AG) of reference SNP (rs) 1799852 (P = 0.01 and 0.03, respectively) and sTfR concentrations were significantly higher (P = 0.004) than the homozygote minor allele genotype (AA), whereas transferrin receptor and BI concentrations were significantly lower in the heterozygote genotype (AG) of rs3811647 (both P = 0.03) than the homozygote wild-type (AA) and minor allele groups (GG). The chromosome 6 allele combination (AAA) consisting of rs1799964 and rs1800629 both in tumor necrosis factor-α (TNF-α) and rs2071592 in nuclear factor κB inhibitor-like protein 1 (NFKBIL1) was associated with higher odds for low SF concentrations (SF < 15 μg/L; OR: 1.86; 95% CI: 1.23, 2.79) than the allele combinations AGA, GGT, and AGT. The chromosome 22 allele combination (GG) consisting of rs228918 and rs228921 in the transmembrane protease serine 6 (TMPRSS6) gene was associated with lower odds for increased sTfR concentrations (sTfR > 8.3mg/L; OR: 0.79; 95% CI: 0.63, 0.98) than the allele combination AA.

CONCLUSIONS

Various SNPs and allele combinations in the TF, TNF-α, and TMPRSS6 genes are associated with iron status in black South African women; however, these association patterns are different compared with European ancestry populations. This stresses the need for population-specific genomic data.

Low BMI is inversely associated with arterial stiffness in Africans

In low socio-economic status communities in South Africa, African men showed a low BMI. Data on the effect of low BMI on cardiovascular function are scant. The present study aimed to assess the associations between low BMI and markers of cardiovascular function such as pulse wave velocity (PWV) and blood pressure in Africans aged 35-65 years, with low socio-economic status. The study population (n 496) was stratified into a low-BMI group with BMI ≤ 20 kg/m² and a normal-BMI group with BMI >20 kg/m² and ≤ 25 kg/m². Blood pressure (Omron HEM-757) and PWV (Complior SP; Artech-Medical) was determined. Africans with low BMI showed an increased arterial stiffness with significantly higher PWV compared with the normal-BMI group (men: P= 0.001; women: P= 0.026), which remained after adjustment. In men with low BMI, PWV correlated negatively with BMI before (r -0.204; P= 0.012) and after (r -0.200; P= 0.020) adjustment. Forward stepwise regression analyses indicated a negative association between PWV and BMI in African men. A J-curve was evident suggesting a detrimental effect of low BMI on cardiovascular function in Africans. A low BMI may contribute to the high prevalence of cardiovascular-related morbidity and mortality within a developing country.

Diagnostic morphology: biophysical indicators for iron-driven inflammatory diseases

Most non-communicable diseases involve inflammatory changes in one or more vascular systems, and there is considerable evidence that unliganded iron plays major roles in this. Most studies concentrate on biochemical changes, but there are important biophysical correlates. Here we summarize recent microscopy-based observations to the effect that iron can have major effects on erythrocyte morphology, on erythrocyte deformability and on both fibrinogen polymerization and the consequent structure of the fibrin clots formed, each of which contributes significantly and negatively to such diseases. We highlight in particular type 2 diabetes mellitus, ischemic thrombotic stroke, systemic lupus erythematosus, hereditary hemochromatosis and Alzheimer's disease, while recognizing that many other diseases have co-morbidities (and similar causes). Inflammatory biomarkers such as ferritin and fibrinogen are themselves inflammatory, creating a positive feedback that exacerbates disease progression. The biophysical correlates we describe may provide novel, inexpensive and useful biomarkers of the therapeutic benefits of successful treatments.

Dietary patterns and physical inactivity, two contributing factors to the double burden of malnutrition among adults in Burkina Faso, West Africa

A population-based cross-sectional study was carried out in the northern neighbourhoods of Ouagadougou (Burkina Faso), to examine the relationship of nutritional deficiencies and cardiometabolic risk factors (CMRF) with lifestyle in adults. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected. We performed anthropometric, dietary intake and physical activity measurements, and blood sample collection. Cluster analysis of dietary intake identified two dietary patterns: 'urban' (29 % of subjects) and 'traditional' (71 %). The 'urban' cluster exhibited a higher intake of fat and sugar, whereas a higher intake of plant protein, complex carbohydrate and fibre was observed in the 'traditional' pattern. Female sex, low income and lack of education were associated with the 'traditional' cluster, as well as Fe and vitamin A deficiency. CMRF prevalence (abdominal obesity, hypertension, hyperglycaemia, dyslipidaemia) was similar in both clusters. Subjects in the 'traditional' cluster spent more time in physical activity and had less sedentary time than those in the 'urban' cluster. 'Traditional' dietary pattern, low income, female sex and sedentary time were significant contributing factors to the double burden of malnutrition. The rapid nutrition transition is reflected in this co-occurrence of CMRF and nutritional deficiencies. This stresses the need for prevention strategies addressing both ends of the nutrition spectrum.

Anthropometric and Iron Status of Adolescents From Selected Secondary Schools in Ogun State, Nigeria

Purpose. We assessed the anthropometric and iron status of adolescents from selected secondary schools in Ogun State, Nigeria. Methods. In this cross-sectional study, anthropometric data, nutrient data, and blood samples were collected from 127 adolescents in Nigeria. Demographic information of the adolescents was obtained in the language of choice using validated questionnaires. Anthropometric indices (weight and height), multiple iron status indicator (hemoglobin, serum ferritin, and transferrin receptor) and inflammation marker (C-reactive protein) were measured using standard procedures. Subjects were classified by body mass index (BMI) categories as underweight, normal weight, at risk of overweight, and overweight according to the World Health Organization standard. Results. The mean age of the subjects was 16.0 ± 2.3 years. Majority of the subjects (55.1%) had normal BMI values, 21.3% were underweight, and 14.2% were overweight. Boys had significantly (<0.05) higher mean intake for energy and most nutrients than girls. The dietary iron intake of the adolescents was unsatisfactory, with approximately 80% of the subjects failing to meet RNI level. Using multiple criteria of iron indicators, the prevalence of iron depletion and iron deficiency in the adolescents were 7.9% and 15.0%, respectively. The prevalence of anemia was high (24.4%), with iron deficiency anemia being the most (71%) prevalent. In both boys and girls, ferritin correlated positively with BMI, waist circumference, and waist–hip ratio. Conclusions. This study documented a high prevalence of iron deficiency and poor nutritional status among Nigeria adolescents, which can be used as basic for dietary support and nutritional education to improve their iron status.

Synergy of iron, high sensitivity C-reactive protein and ceruloplasmin with oxidative stress in non-diabetic normo-tensive South Indian obese men

BACKGROUND

Oxidative stress and inflammation are implicated in the pathogenesis of obesity and its related complications. Previous studies have suggested a potential link between obesity and altered iron metabolism. The present study was designed to evaluate iron, C-reactive protein, ceruloplasmin and oxidative stress and their association, if any, in non-diabetic normo-tensive South Indian obese men.

METHODS

30 obese men and 30 age-matched males with normal body weight were recruited in the study. Serum iron, copper, ceruloplasmin, high sensitivity C-reactive protein (hs-CRP), malondialdehyde, protein carbonyl, total oxidant status and total antioxidant status were estimated in all the subjects.

RESULTS

Serum iron, ceruloplasmin, high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), protein carbonyl and total oxidant status were significantly increased and total antioxidant status was significantly reduced in obese men, compared to controls. Linear regression analysis shows highly significant positive association of iron with hs-CRP.

CONCLUSION

The data from the present study concludes that oxidative stress parameters, hs-CRP, iron and ceruloplasmin were significantly elevated in obese Indian men, suggesting they are more prone to develop cardiovascular disease, than age-matched men with normal body weight.

Relationship of physical activity to cardiovascular risk factors in an urban population of Nigerian adults

BACKGROUND

The burden of chronic diseases including cardiovascular disease (CVD) is increasing rapidly in Nigeria, but fewer studies have evaluated the role of physical activity in the development of CVD in this country. We examined the relationship between health enhancing physical activity and risk factors of CVD in a working population of adults in Maiduguri, Nigeria.

METHODS

In a cross-sectional study, we assessed health enhancing moderate-to-vigorous physical activity (MVPA) among 292 government employees (age: 20-65 years, 40% female, 24% obese and 79.8% response) using the self-administered version of International Physical Activity Questionnaire (IPAQ-SF). Time spent in walking and sitting during occupational activity was assessed as well. Anthropometric measurement of height, weight and waist circumference, and blood pressure were also measured. Independent t-test and One- Way ANOVA were conducted, and the relationships between MVPA and body mass index (BMI), waist circumference, blood pressure and heart rate were explored using Pearson correlations coefficients and multiple regression analyses.

RESULTS

The mean time spent in health enhancing MVPA (116.4 ± 101.3 min/wk) was lower than the recommended guideline of 150 min/wk sufficient for health benefits. Compared with men, more women were less physically active, obese and reported more diagnoses of component of metabolic syndrome (p < 0.05). Participants whose work activities were highly sedentary tend to accumulate less minutes of MVPA compared with those who reported their work as moderately active or highly active (p < 0.001). Health enhancing MVPA was inversely related with body mass index (BMI), waist circumference, heart rate, and systolic and diastolic blood pressure (p < 0.05).

CONCLUSION

Physical activity level of the working population of Nigerian adults was low and was related with adverse risk factors for CVD. Promoting health enhancing physical activity at work places may be important for prevention and control of CVD among the working population in Maiduguri, Nigeria.

Association of high-sensitivity C-reactive protein with cardiometabolic risk factors and micronutrient deficiencies in adults of Ouagadougou, Burkina Faso

Increasing evidence suggests that high-sensitivity C-reactive protein (hs-CRP) is associated with cardiometabolic risk factors (CMRF) while being also related to micronutrient deficiencies. As part of a project on the double burden of under- and overnutrition in sub-Saharan Africa, we assessed the relationship between hs-CRP and both CMRF and micronutrient deficiencies in a population-based cross-sectional study carried out in the Northern district of Ouagadougou, the capital city of Burkina Faso. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected, and underwent anthropometric measurements and blood sample collection. The prevalence of high hs-CRP was 39.4 %, with no sex difference. Vitamin A-deficient subjects (12.7 %) exhibited significant risk of elevated hs-CRP (OR 2.5; P= 0.015). Serum ferritin was positively correlated with log hs-CRP (r 0.194; P= 0.002). The risk of elevated hs-CRP was significant in subjects with BMI ≥ 25 kg/m² (OR 6.9; 95 % CI 3.6, 13.3), abdominal obesity (OR 4.6; 95 % CI 2.2, 7.3) and high body fat (OR 10.2; 95 % CI 5.1, 20.3) (P< 0.001, respectively). Independent predictors of hs-CRP in linear regression models were waist circumference (β = 0.306; P= 0.018) and serum TAG (β = 0.158; P= 0.027). In this sub-Saharan population, hs-CRP was consistently associated with adiposity. Assuming that plasma hs-CRP reflects future risk of cardiovascular events, intervention which reduces CRP, or chronic and acute nutrition conditions associated with it, could be effective in preventing their occurrence particularly in sub-Saharan Africa.

Antitumor activity of cell-permeable p18(INK4c) with enhanced membrane and tissue penetration

Practical methods to deliver proteins systemically in animals have been hampered by poor tissue penetration and inefficient cytoplasmic localization of internalized proteins. We therefore pursued the development of improved macromolecule transduction domains (MTDs) and tested their ability to deliver therapeutically active p18(INK4c). MTD103 was identified from a screen of 1,500 signal peptides; tested for the ability to promote protein uptake by cells and tissues; and analyzed with regard to the mechanism of protein uptake and the delivery of biologically active p18(INK4c) into cancer cells. The therapeutic potential of cell-permeable MTD103p18(INK4c) (CP-p18(INK4c)) was tested in the HCT116 tumor xenograft model. MTD103p18(INK4c) appeared to traverse plasma membranes directly, was transferred from cell-to-cell and was therapeutically effective against cancer xenografts, inhibiting tumor growth by 86-98% after 5 weeks (P < 0.05). The therapeutic responses to CP-p18(INK4c) were accompanied by high levels of apoptosis in tumor cells. In addition to enhancing systemic delivery of CP-p18(INK4c) to normal tissues and cancer xenografts, the MTD103 sequence delayed protein clearance from the blood, liver and spleen. These results demonstrate that macromolecule intracellular transduction technology (MITT), enabled by MTDs, may provide novel protein therapies against cancer and other diseases.