Iron Status and Metabolically Unhealthy Obesity in Prepubertal Children

Abstract

Objective This study aimed to evaluate the association of metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) with iron status markers in prepubertal children. Methods Three hundred twelve prepubertal children with overweight and obesity from a pediatric general Spanish population were evaluated. MHO and MUO were defined as obesity with the absence or presence of metabolic syndrome components. Phenotypes of metabolically healthy overweight including obesity (MHOV) and metabolically unhealthy overweight including obesity (MUOV) were also studied and defined using the same criteria. Serum ferritin, transferrin, and blood hemoglobin levels were evaluated. Results Prevalence rates of MHOV and MHO were 35% (n = 111/312) and 27.1% (n = 42/155), respectively. Ferritin and hemoglobin levels were higher in children with MUOV versus MHOV (P < 0.05). MUO was positively associated with ferritin (beta [95% CI] = 0.43 [0.05 to 0.81]) and hemoglobin levels (0.43 [0.05 to 0.81]). These associations remained significant independently of age, sex, C‐reactive protein, physical activity, and BMI/waist z scores in bivariate linear regression models. In multivariable models, transaminase levels attenuated the association of MUO with ferritin and hemoglobin levels (P > 0.05). Conclusions MUOV and MUO are associated with higher ferritin and hemoglobin levels in prepubertal children affected by overweight and obesity. Increased circulating ferritin in MUO might be influenced by liver injury.

Iron Metabolism in Obesity and Metabolic Syndrome

“…Rodent models lacking the active ferritin subunit (H-Ft) are unable to develop HFD-induced obesity, as the reduction of intracellular iron deposits ameliorates the inflammatory state [ 119 ]. In a study on the association of metabolic health in obesity and iron status markers in prepubescent children, Suárez-Ortegón et al found circulating ferritin levels to be related to metabolically unhealthy obesity [ 120 ].…”

A Proteomics-Based Approach Reveals Differential Regulation of Urine Proteins between Metabolically Healthy and Unhealthy Obese Patients

“…Transferrins transport iron from sites of absorption and heme degradation to those of storage and utilization [14,15]. In our study, the MUHO group showed a 1.5-fold increase in urinary excreted TRFE compared to the MHO group.…”

“…The low-grade chronic inflammatory response associated with obesity may contribute to the TRFE changes observed in the MUHO group. TRFE acts as a negative acute phase reactant whose levels are reduced during inflammation to limit the circulating iron and to prompt the sequestration of iron in macrophages to modulate host defenses [15,16]. We think that a positive relationship exists between the severity of obesity and urinary TRFE, because we previously noted a significant reduction in the urinary TRFE levels in obese people in response to either a low-calorie diet or bariatric surgery [17].…”

Association of Alanine Aminotransferase With Different Metabolic Phenotypes of Obesity in Children and Adolescents: The CASPIAN-V Study

“…In line with our study, Aldhoon-Hainerová et al found that alanine aminotransferase could differentiate MNHO from Metabolically Health without abdominal obesity in both sexes in adolescence and from Metabolically Health regardless of waist circumference obesity in boys ( 8 ). Likewise, Suárez-Ortegón et al observed a higher serum ALT level in children with MNHO (vs. MHO), and metabolically unhealthy overweight (vs. metabolically healthy overweight) ( 9 ). Xie et al in a cross-sectional study on 2,197 obese (BMI ≥25 kg/m2) adults older than 40 years observed that the ALT might be an effective marker for identifying MNHO in this population ( 10 ).…”

“…While a large number of studies showed the association of liver enzymes with cardio-metabolic components and metabolic syndrome (6,7), a few studies have examined the association of these enzymes with the different metabolic phenotypes of obesity, especially in children and adolescents (8)(9)(10). Therefore, this study aims to determine the association of ALT level with different metabolic phenotypes of obesity in children and adolescents.…”