Hepcidin and iron metabolism associated with cardiometabolic risk factors in children: A case-control study

Ferritin levels throughout childhood and metabolic syndrome in adolescent stage

BACKGROUND AND AIM

Increased ferritin levels have been widely associated with cardiovascular risk in adults. Whether ferritin levels and their changes during childhood are related to metabolic syndrome (MetS) at adolescence is unknown. We aimed to evaluate these associations using levels of ferritin at 5, 10 and 16 years and their linear increases and patterns of sustained increased levels across childhood.

METHODS AND RESULTS

There were four samples evaluated according to non-missing values for study variables at each stage (5 years: 562; 10 years: 381; and 16 years: 567 children; non-missing values at any stage: 379). MetS risk was evaluated as a continuous Z score. Patterns of sustained increased ferritin (highest tertile) and slope of the change of ferritin per year across the follow-up were calculated. Ferritin levels in the highest versus lowest tertile at five and 16 years were significantly positively associated with MetS risk Z score at adolescence in boys and these associations were unaffected by adjustment for covariates. Having high, compared to low/moderate ferritin level at 2 or more time periods between 5 and 16 years was related to higher Mets Z-score in boys only [e.g. 5-10 years adjusted-beta (95 %CI):0.26 (0.05-0.48),P < 0.05]. In girls, ferritin Z score at 10 and 16 years was positively and independently associated with HOMA-IR Z score. In girls, the slope of ferritin per year in the highest tertile was positively associated with MetS risk Z-score [adjusted-beta (95 %CI):0.21 (0.05-0.38),P < 0.05].

CONCLUSIONS

Ferritin levels throughout childhood are positively related to cardiometabolic risk in adolescence, with associations varying by sex.

Iron metabolism and its association with dyslipidemia risk in children and adolescents: a cross-sectional study

Background

Information on the association between iron metabolism and dyslipidaemia in children is limited. Thus, this study aims to evaluate the iron metabolic status of children with different body mass index (BMI) and to examine the association between iron metabolism and dyslipidaemia risk.

Method

In total, 1866 children and adolescents aged 7–18 were enrolled in this study, including 912 boys and 954 girls. In this cross-sectional study, parameters for anthropometry, lipids and iron metabolism including transferrin, soluble transferrin receptor (sTfR), ferritin and serum iron (SF) were evaluated. Data regarding demographic characteristics, diet, and physical activity were collected by self-reported questionnaires.

Results

The prevalence of dyslipidaemia and iron deficiency in children and adolescents increased based on BMI categories (both P < 0.05) and were 58.3 and 8.9% in subjects with obesity, respectively. The lowest SF and the highest ferritin levels were observed in subjects who were obese (both P < 0.001). Subjects with dyslipidaemia had lower SF, transferrin and sTfR levels by different BMI categories, and those who were obese had higher ferritin levels (all P < 0.05). Most importantly, higher concentrations of transferrin and sTfR were related to lower dyslipidaemia risk (OR for transferrin: 0.49, 95% CI: 0.33–0.71; OR for sTfR: 0.68, 95% CI: 0.46–0.99).

Conclusions

A downward trend in SF level by BMI categories and the highest ferritin level in subjects with obesity suggested that iron storage was associated with BMI in children and adolescents. Moreover, an inverse relationship was observed between transferrin and sTfR concentrations and dyslipidaemia risk in children with different BMI.

Molecular Fingerprints of Iron Parameters among a Population-Based Sample

Iron deficiency is the most frequent deficiency disease and parameters of iron metabolism appear to be linked to major metabolic and cardiovascular diseases. We screened a large set of small molecules in plasma for associations with iron status among apparently healthy subjects to elucidate subclinical profiles which may provide a link between iron status and onset of diseases. Based on mass spectrometry and nuclear magnetic resonance spectroscopy we determined 613 plasma metabolites and lipoprotein subfractions among 820 apparently healthy individuals. Associations between ferritin, transferrin, haemoglobin and myoglobin and metabolite levels were tested by sex-specific linear regression analyses controlling for common confounders. Far more significant associations in women (82 out of 102) compared to men became obvious. The majority of the metabolites associated with serum ferritin and haemoglobin in women comprising fatty acid species, branched-chain amino acid catabolites and catabolites of heme. The latter was also obvious among men. Positive associations between serum transferrin and VLDL and IDL particle measures seen in women were observed in men with respect to serum ferritin. We observed a sexual-dimorphic fingerprint of surrogates of iron metabolism which may provide a link for the associations between those parameters and major metabolic and cardiovascular disease.