Changes in obesity and iron deficiency between 4 and 9 years of age. Longitudinal study of childhood obesity (ELOIN)

Relationship between Anemia and Anthropometric Profile in Tabari Cohort Population: A Case-Control Study

BACKGROUND

Anemia is a common blood disorder in developing countries and is associated with diseases such as diabetes, as well as cardiovascular and pulmonary diseases. This study aimed to investigate the relationship between anemia and anthropometric profiles in the Tabari cohort population. Study Design: A case-control study.

METHODS

In this study, we used a subset of data collected during the first phase of the Tabari cohort study (TCS). All participants who had anemia were included in the case group (1352 individuals) using the census method. The control group (1352 individuals) consisted of participants who did not have anemia and were randomly selected from the remaining participants. The case and control groups were matched for age and gender. Anthropometric indices, including body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR), were measured by qualified and trained persons. Hematological indices were measured, and data were analyzed using the chi-square test and independent t test. A multiple logistic regression analysis was used to adjust for possible confounding variables.

RESULTS

The place of residence, education level, socioeconomic status, WC, BMI, and WHR were significantly different between the case and control groups (P<0.05). Anthropometric indices, including BMI (adjusted OR=0.75; 95 % CI 0.61, 0.91), WC (adjusted OR=0.86; 95 % CI 0.74, 1.00), and WHR (adjusted OR=0.75; 95 % CI 0.64, 0.88), were significantly different between the case and control groups (P<0.05).

CONCLUSION

Anthropometric indices were associated with anemia, and participants with higher BMI, WC, and WHR were less likely to develop anemia.

The Interplay Between Iron Metabolism and Insulin Resistance: A Key Factor in Optimizing Obesity Management in Children and Adolescents

Iron plays a vital role in insulin signaling, regulating molecular mechanisms that influence cellular insulin responses. This review explores the link between iron metabolism and insulin resistance (IR) in children and adolescents with obesity. A connection between iron metabolism, iron deficiency (ID), and IR is well-documented, but further longitudinal studies are needed to better understand how iron metabolism influences insulin resistance during childhood and adolescence. This connection warrants attention due to its significant public health implications, as optimizing obesity management could help prevent both ID and metabolic complications in children. Current evidence does not suggest that dietary factors are primary contributors to ID in children. However, there is scientific evidence that weight reduction can restore iron homeostasis in people with obesity. Therefore, efforts should focus on improving dietary habits, increasing awareness of iron's importance, and implementing strategies to address both ID and obesity.

Overnutrition is a risk factor for iron, but not for zinc or vitamin A deficiency in children and young people: a systematic review and meta-analysis

INTRODUCTION

Traditionally associated with undernutrition, increasing evidence suggests micronutrient deficiencies can coexist with overnutrition. Therefore, this work aimed to systematically review the associations between iron, zinc and vitamin A (VA) status and weight status (both underweight and overweight) in children and young people.

METHODS

Ovid Medline, Ovid Embase, Scopus and Cochrane databases were systematically searched for observational studies assessing micronutrient status (blood, serum or plasma levels of iron, zinc or VA biomarkers) and weight status (body mass index or other anthropometric measurement) in humans under 25 years of any ethnicity and gender. Risk of bias assessment was conducted using the American Dietetic Association Quality Criteria Checklist. Where possible, random effects restricted maximum likelihood meta-analyses were performed.

RESULTS

After screening, 83 observational studies involving 190 443 participants from 44 countries were identified, with many studies having reported on more than one micronutrient and/or weight status indicator. Iron was the most investigated micronutrient, with 46, 28 and 27 studies reporting data for iron, zinc and VA status, respectively. Synthesising 16 records of OR from seven eligible studies, overnutrition (overweight and obesity) increased odds of iron deficiency (ID) (OR (95% CI): 1.51 (1.20 to 1.82), p<0.0001, I2=40.7%). Odds appeared to be higher for children living with obesity (1.88 (1.33 to 2.43), p<0.0001, I2=20.6%) in comparison to those with overweight (1.31 (0.98 to 1.64), p<0.0001, I2=40.5%), although between group differences were not significant (p=0.08).

CONCLUSIONS

Overnutrition is associated with increased risk of ID, but not zinc or VA deficiencies, with an inverted U-shaped relationship observed between iron status and bodyweight. Our results highlight significant heterogeneity in the reporting of micronutrient biomarkers and how deficiencies were defined. Inflammation status was rarely adequately accounted for, and the burden of ID may well be under-recognised, particularly in children and young people living with overnutrition.

PROSPERO REGISTRATION NUMBER

CRD42020221523.