Circulating microRNAs and hepcidin as predictors of iron homeostasis and anemia among school children: a biochemical and cross-sectional survey analysis

BACKGROUND

MicroRNAs (miRNAs) can control several biological processes. Thus, the existence of these molecules plays a significant role in regulating human iron metabolism or homeostasis.

PURPOSE

The study aimed to determine the role of circulating microRNAs and hepcidin in controlling iron homeostasis and evaluating possible anemia among school children.

METHODS

The study was based on a biochemical and cross-sectional survey study that included three hundred fifty school children aged 12-18 years old. RT-PCR and immunoassay analysis were accomplished to estimate iron concentration, Hgb, serum ferritin (SF), soluble transferrin receptor (sTfR), total body iron stores (TIBs), total oxidative stress (TOS), total antioxidant capacity (TAC), α-1-acid glycoprotein (AGP), high sensitive C-reactive protein (hs-CRP), and miRNAs; miR-146a, miR-129b, and miR-122 in 350 school adolescents.

RESULTS

Iron disorders were cross-sectionally predicted in 28.54% of the study population; they were classified into 14.26% with ID, 5.7% with IDA, and 8.6% with iron overload. The overall proportion of iron depletion was significantly higher in girls (20.0%) than in boys (8.6%). MicroRNAs; miR-146a, miR-125b, and miR-122 were significantly upregulated with lower hepcidin expression in adolescence with ID and IDA compared to iron-overloaded subjects, whereas downregulation of these miRNAs was linked with higher hepcidin. Also, a significant correlation was recorded between miRNAs, hepcidin levels, AGP, hs-CRP, TAC, and other iron-related indicators.

CONCLUSION

Molecular microRNAs such as miR-146a, miR-125b, and miR-122 were shown to provide an additional means of controlling or regulating cellular iron uptake or metabolism either via the oxidative stress pathway or regulation of hepcidin expression via activating genes encoding Hfe and Hjv activators, which promote iron regulation. Thus, circulating miRNAs as molecular markers and serum hepcidin could provide an additional means of controlling or regulating cellular iron and be associated as valuable markers in diagnosing and treating cases with different iron deficiencies.

Knowledge Gaps in Understanding the Etiology of Anemia in Indonesian Adolescents

BACKGROUND

Anemia is a public health problem among adolescents in Indonesia. Strategies to prevent or treat anemia should be tailored to local conditions, taking into account its specific etiology and prevalence in a given setting and population group.

OBJECTIVE

This review aims to (1) identify and synthesize the current knowledge on the etiology of anemia among adolescents in Indonesia, (2) reveal knowledge gaps in this area, and (3) suggest directions for future research and programmatic work.

METHODS

We systematically searched PubMed, Web of Science, Scopus, Medline, and WorldCat databases for peer-reviewed journal articles to identify which etiological factors were related to anemia among Indonesian adolescents. Research papers were reviewed and included in the review according to inclusion criteria.

RESULTS

Of 13 studies, 8 showed that anemia was associated with iron deficiency; 4 are suggestive of vitamin A deficiency; and 2 of folic acid deficiency. Five studies underscore different etiological determinants for anemia, such as malaria, protein and energy malnutrition, vitamin B2 deficiency, calcium, and vitamin C deficiency. Based on these findings, we developed a framework on knowledge gaps on the etiology of anemia among adolescents in Indonesia, divided in 3 levels of knowledge: (1) significant knowledge gaps, (2) knowledge gaps, and (3) established knowledge.

CONCLUSIONS

The knowledge gaps around the etiology of anemia among Indonesian adolescents are significant. Our framework emphasizes the need for further research across all etiological factors, namely inadequate nutritional intake and absorption, genetic hemoglobin disorders, infection and inflammation, and menstrual disorders.

Two measures of systemic inflammation are positively associated with haemoglobin levels in adolescent girls living in rural India: a cross-sectional study

OBJECTIVE

This study tested the hypothesis that systemic inflammation is inversely associated with haemoglobin levels in adolescent girls in India.

METHODS

The study population consisted of adolescent girls aged between 10 and 19 years living in a remote rural region in Maharashtra State, India. Data were collected on anthropometric measures, and a venous blood sample was taken and tested for complete blood count and C-reactive protein (CRP).

RESULTS

Of 679 individuals who were invited to the research site to participate, data were available from 401 participants giving a response rate of 59%. Median blood CRP was 1.26 mg/l (Range 0.00 to 26.33), and 167 (41.6%) participants had CRP level < 1.0 mg/l. The mean haemoglobin was 12.24 g/dl (standard deviation [SD] 1.51), and the mean total white blood cells (WBC) count was 9.02 × 10³ /μl (SD 2.00). With each g/dl increase in blood haemoglobin, the risk of having an elevated CRP of ≥ 1 mg/l increased with an odds ratio of 1.16 (95% CI 1.01 to 1.33, P = 0.03). Total WBC count was also positively associated with blood haemoglobin, increasing by 0.24 × 10³ /μl (95% CI 0.11 to 0.37, P < 0.001) per g/dl increase in haemoglobin. Both analyses were adjusted for age.

CONCLUSIONS

In this population, blood haemoglobin levels were positively associated with two measures of systemic inflammation, contrary to the primary hypothesis being tested. Other unmeasured environmental exposures may modify haemoglobin levels in this population. Understanding this observation may help design better public health interventions to improve the well-being of adolescent girls in India.

Is Iron Supplementation Influenced by Sub-Clinical Inflammation?: A Randomized Controlled Trial Among Adolescent Schoolgirls in Myanmar

Iron absorption was impaired in the presence of sub-clinical inflammation (SCI) and might hamper the effect of iron supplementation. The purpose of the study was to identify the influence of SCI on iron supplementation. A randomized, double-blinded, placebo-controlled experimental study was conducted among anaemic adolescent schoolgirls in Ayeyarwady region, Myanmar. A total of 402 schoolgirls were recruited from six schools screened from 1269 girls who were assigned into one of four groups: Folate group (2.5 mg of folate), Vitamin A group (15,000 IU of vitamin), Iron folate group (60 mg elemental iron and folate) and Iron, and vitamin A and folate group. Supplementation was done once a week for 12 weeks. Iron, vitamin A and inflammation were measured at the baseline, middle and endline. Changes in serum ferritin and body iron were significantly higher in the IFA and IFA + vitA among those without SCI. There was interaction between vitamin A and SCI on Hb changes. Analysis of GLM repeated measure showed interactions between treatment and SCI for hemoglobin and serum transferrin receptor. Those treated with vitamin A had better outcomes when there was SCI. Inflammation accompanied a negative effect on iron supplementation and vitamin A improved efficacy of iron supplementation in the presence of SCI.

Potential interventions targeting adolescent nutrition in Indonesia: a literature review

Objective

The present study aimed to take stock of nutrition interventions that warrant consideration as a minimum package of interventions in Indonesia to improve four key nutrition indicators for adolescents: stunting, thinness, overweight and anaemia.

Design

We conducted a review of the peer-reviewed literature published between 1995 and 2017 on nutrition-specific and nutrition-sensitive interventions that target adolescents in Indonesia. The search to identify studies was conducted in PubMed, Google Scholar and EMBASE, using key search terms. We also explored programmatic and policy documents from the grey literature as they related to adolescents and/or Indonesia. Our search yielded thirty-five peer-reviewed articles and programmatic documents.

Setting

Indonesia.

Subjects

Adolescent girls and boys.

Results

There is very limited evidence on the impact of interventions specifically among adolescents in Indonesia. Nevertheless, findings from our review suggest the minimum package of interventions in Indonesia could include the following nutrition-specifc interventions: (i) iron–folic acid supplements, paired with antihelminths delivered at scale via school-based platforms and through health centres; and (ii) diet counselling and nutrition education provided through school-based platforms, adolescent youth centres/peer education and technology-based platforms. The minimum package could also include the following nutrition-sensitive interventions: (i) improving access to reproductive health services; and (ii) increasing the coverage of interventions designed to increase school attendance.

Conclusions

Programmes and policies targeting adolescent nutrition are relatively new and coverage is low. To improve the nutritional status of this vulnerable population, additional evaluations of adolescent programming and surveillance data on adolescents are needed.