Association between biomarkers of iron status and cardiometabolic risk in Spanish children aged 9-10 years. The ELOIN study.

The relationship between iron metabolism and cardiometabolic risk factors has been scarcely studied in children, and the results are controversial. The objective of this study was to evaluate the association between iron parameters and lipid, glycemic and blood pressure alterations in the pediatric population. This was a cross-sectional study of 1954 children between 9 and 10 years of age in Madrid (Spain), participants in a longitudinal study of childhood obesity. Iron metabolism parameters, i.e., serum iron (Is), ferritin (Fs), transferrin (Tf) and transferrin saturation (STf) and lipid, glycemic and blood pressure profiles were evaluated. Odds ratios (ORs) were estimated using logistic regression models adjusted for sociodemographic characteristics, diet, physical activity, C-reactive protein and body mass index. Compared with the participants in the low Is and STf tertiles, those in the upper tertiles had a lower risk of low HDL-Chol (OR: 0.34; 95%CI: 0.17; 0.67) and OR: 0.44 (95%CI: 0.23; 0.84), respectively, and children in the upper Fs tertile had an OR of 2.07 (95%CI: 1.16; 3.68) for low HDL-Chol. Children in the highest Is and STf tertiles had a lower risk of prediabetes [OR: 0.63 (95%CI: 0.41; 0.97) and OR: 0.53 (95%CI: 0.34; 0.82)] and insulin resistance (IR) (OR: 0.37; 95%CI: 0.22; 0.64), and those in the upper Tf tertile had a higher risk of IR (OR: 1.90; 95%CI: 1.16; 3.12). An increased risk of hypertension was found only in children in the upper Fs tertile (OR: 1.46; 95%CI: 1.01; 2.13). CONCLUSIONS: Biomarkers of iron metabolism are associated with cardiometabolic alterations in the pediatric population, with a variable direction and magnitude depending on the indicators used. WHAT IS KNOWN: • Iron metabolism is related to important cardiometabolic alterations such as metabolic syndrome and its components. • Association between biomarkers of iron status and cardiometabolic risk have been less explored in children. WHAT IS NEW: • Biomarkers of iron metabolism are associated with cardiometabolic alterations in the pediatric population. • Iron parameters in the pediatric population could be of great help to detect and prevent cardiometabolic abnormalities early.

Changes in general and abdominal obesity in children at 4, 6 and 9 years of age and their association with other cardiometabolic risk factors.

Temporary changes in childhood obesity and their association with cardiometabolic risk factors have been receiving increased attention. The objective of this study was to evaluate changes in general (GO) and abdominal (AO) obesity in children from 4 to 9 years of age and their associations with cardiometabolic risk factors at 9 years of age. This study includes 1344 children from the Longitudinal Childhood Obesity Study (ELOIN). Physical examinations performed at 4, 6 and 9 years of age and a blood sample was only taken at 9 years of age. Changes in obesity from 4 to 9 years of age were estimated using Body Mass Index and waist circumference. Participants were classified into four groups according to GO and AO: (1) stable without obesity (no obesity at all three measurements); (2) remitting obesity at 9 years (obesity at 4 and/or 6 years but not at 9 years); (3) incident or recurrent obesity at 9 years (obesity only at 9 years, at 4 and 9 years or at 6 and 9 years); and (4) stable or persistent with obesity (obesity at 4, 6 and 9 years). Dyslipidemia and dysglycemia were defined by the presence of at least one altered parameter of the lipid or glycemic profile. Odds ratios (OR) were estimated using logistic regression. Compared with children without GO at all ages, those with persistent GO had an OR of 3.66 (95% CI: 2.06-6.51) for dyslipidemia, 10.61 (95% CI: 5.69-19.79) for dysglycemia and 8.35 (95% CI: 4.55-15.30) for high blood pressure. The associations were fairly similar in the case of AO, with ORs of 3.52 (95% CI: 1.96-6.34), 17.15 (95% CI: 9.09-32.34) and 8.22 (95% CI: 4.46-15.15), respectively, when comparing persistent versus stable without AO. Children with incident obesity at 9 years presented a moderate cardiometabolic risk that was nevertheless higher compared to those stable without obesity, whereas those with remitting obesity did not show any significant associations. CONCLUSION: Incident, and especially, persistent obesity, is associated with an increased cardiometabolic risk. The very early prevention of obesity, with a focus on nutrition, physical activity and sedentary behaviour, as well as tracking growth from birth to age 5, should be a priority to prevent the burden of cardiometabolic disease with consequences for adulthood. WHAT IS KNOWN: • General and abdominal obesity has been shown to be associated with other cardiometabolic risk factors such as dyslipidemia, insulin resistance and hypertension. • Temporary changes in obesity and their associations with cardiometabolic risk factors have not been sufficiently explored in childhood. WHAT IS NEW: • Children with incident, and especially persistent, general and/or abdominal obesity, had an increased risk of dyslipidemia, dysglycemia and high blood pressure. •Remitting obesity was not associated with an increased cardiometabolic risk.

Household food insecurity and its association with overweight and obesity in children aged 2 to 14 years.

BACKGROUND: The objective was to estimate the prevalence of household food insecurity (HFI) depending on sociodemographic factors and its association with lifestyle habits and childhood overweight and obesity. METHODS: Data was collected from 1,938 children aged 2 to 14 years who participated in the "Study about Malnutrition" of the Community of Madrid. Weight and height were obtained through physical examination. Body mass index was calculated as weight/height2 (kg/m2) and the criteria of the WHO were used for determining conditions of overweight and obesity. The participants' parents answered a structured questionnaire about their diet, lifestyle (physical activity and screen time), and food insecurity. The diet quality was assessed with the Healthy Eating Index in Spain and food insecurity, defined as the lack of consistent access to sufficient food for a healthy life, was measured via three screening questions and the Household Food Insecurity Access Scale (HFIAS). Odds Ratios (ORs) and Relative Risk Ratios (RRRs) were estimated using logistic regression models and adjusted for confounding variables. RESULTS: The overall prevalence of HFI was 7.7% (95% CI: 6.6‒9.0), with lower values in children 2 to 4 years old (5.7%, 95% CI: 4.0‒8.1) and significantly higher values in households with low family purchasing power [37.3%; OR: 8.99 (95% CI: 5.5‒14.6)]. A higher prevalence of overweight (33.1%) and obesity (28.4%) was observed in children from families with HFI, who presented a lower quality diet and longer screen time compared to those from food-secure households (21.0% and 11.5%, respectively). The RRR of children in families with HFI relative to those from food-secure households was 2.41 (95% CI: 1.5‒4.0) for overweight and 1.99 (95% CI: 1.2‒3.4) for obesity. CONCLUSION: The prevalence of HFI was high in the paediatric population, especially in households with low family purchasing power. HFI was associated with lower diet quality and higher prevalence of childhood overweight and obesity. Our results suggest the need for paediatric services to detect at-risk households at an early stage to avoid this dual burden of child malnutrition.

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

BACKGROUND: Recent studies revealed that children who are overweight have a higher risk of iron deficiency, although the etiology of this relationship remains unclear. The aim of the study was to evaluate the association between changes in obesity status between 4 and 9 years of age and iron deficiency. SUBJECTS: This population-based cohort study included 1347 children from the ELOIN study, conducted in Madrid, Spain. Follow-up with physical examinations and a computer-assisted telephone interview were carried out at 4, 6 and 9 years of age, and a blood test was performed at 9 years. METHODS: Changes in obesity were estimated based on body mass index and waist circumference, according to the persistence or variation in obesity rates at 4, 6 and 9 years and were classified as follows: (1) Stable without obesity; (2) Remitting obesity at 9 years; (3) Incident obesity or relapse at 9 years; and (4) Stable with obesity. Iron deficiency was defined as transferrin saturation value below 16%. Odds ratios (ORs) for iron deficiency were estimated according to obesity status using logistic regression and adjusted for confounding variables, including C-reactive protein (CRP). RESULTS: The prevalence of iron deficiency in the stable general obesity (GO) and abdominal obesity (AO) groups was 38.2% and 41.2%, versus 23.6% and 23.4% in the stable without obesity groups, respectively. The ORs for iron deficiency were 1.85 (95% CI: 1.03-3.32) in the stable GO group and 2.34 (95% CI: 1.29-4.24) in the stable AO group. This association disappeared when CRP was included in the analysis. CONCLUSIONS: An extended state of obesity during the first stages of life is associated with iron deficiency, and this association may be mediated by CRP. Prevention and early detection of obesity in children should be a priority to avoid a double burden of malnutrition.

Tracking and risk of abdominal and general obesity in children between 4 and 9 years of age. The Longitudinal Childhood Obesity Study (ELOIN).

BACKGROUND: Studies have shown that overweight and obesity conditions tend to be stable from childhood and adolescence to adulthood. Unfortunately, little is known about the evolution of abdominal obesity during childhood. The aim of this study was to evaluate the temporal variations and risk of general and abdominal obesity between 4, 6, and 9 years of age. METHODS: Measurements of children in the ELOIN study taken at the three follow-ups of 4, 6, and 9 years of age were included (N = 1,902). Body mass index and waist circumference were recorded via physical examination. General obesity was determined according to the criteria of the World Health Organization (WHO) and abdominal obesity according to the cut-off points proposed by the International Diabetes Federation (IDF). Prevalence ratios (PRs) were estimated by sex and family affluence using generalized estimating equation models and relative risks (RRs) of obesity were obtained via Poisson regression. RESULTS: The prevalence of general obesity was 5.1%, 9.1%, and 15.6% at 4, 6, and 9 years, respectively, yielding a PR of 3.05 (95%CI: 2.55-3.60) (9 years old relative to 4 years). The prevalence of abdominal obesity was 6.8%, 8.4%, 14.5% at 4, 6, and 9 years, respectively, and the PR was 2.14 (95%CI: 1.82-2.51) (9 years old relative to 4 years). An inverse correlation was observed between both general and abdominal obesity and socioeconomic status. Among participants with general or abdominal obesity at 4 years of age, 77.3% and 63.6% remained in their obesity classification at 9 years, respectively, and 3.4% and 3.5% presented general or abdominal obesity also at 6 and 9 years of age, respectively. The RRs of general and abdominal obesity at 9 years were 4.61 (95%CI: 2.76-7.72) and 4.14 (95%CI: 2.65-6.48) for children classified with obesity at 4 years of age, increased to 9.36 (95%CI: 7.72-11.35) and 9.56 (95%CI: 7.79-11.74) for children who had obesity at 6 years, and up to 10.27 (95%CI: 8.52-12.37) and 9.88 (95%CI: 8.07-12.11) for children with obesity at both 4 and 6 years, respectively. CONCLUSIONS: General and abdominal obesity begin at an early age and increase over time, showing an inverse correlation with socioeconomic status. In addition, general and abdominal obesity at 9 years are strongly associated with being classified with obesity at 4 and 6 years, so preventive interventions should be established at very early ages.