Objective: Disorders of glucose metabolism in children with obesity are less common than in adults. There is also evidence that they may be transient. The aims of this study were to determine the prevalences of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (DM2) and its reversibility in pediatric patients with obesity and to define the factors determining the reversibility of prediabetes or progression to diabetes. Methods: Retrospective analysis included of young patients with obesity. Patients presented and were treated between 2000-2022 at a single center. Results: The study included 573 (316 girls; 55.15%) Caucasian patients with median body mass index (BMI) Z-score of 3.95 (range 2.09.9) and median age 13.9 (2.9-17.1) years old. OGTT results were normal in 90.8% (n=520) and signs of prediabetes occurred in 9.2% (n=53); IFG 17%, IGT 88.7%, DM 0%. Among those who underwent OGTT twice (n=53), impaired glucose regulation was present in 9.3% (n=5) (IFG 40%, IGT 80%, DM 0%) at baseline and in 14.8% subject (n=8) (IFG 25%, IGT 50%, DM 25%) at follow-up after lifestyle modification only. After 12-36 months of follow up, in those with a history of IGT, 60% reverted to normal glucose tolerance, while IFG and IGT persisted in 20% and 20%, respectively, and none progressed to DM. The risk factors for progression of glucose metabolism disorders were increase of BMI Z-score, higher insulin levels and elevated homeostatic model assessment-insulin resistance. Conclusion: IFG and IGT are common in pediatric patients with obesity, while the progression to DM2 is rare. Disorders of glucose metabolism have reversible character.

Aim: To assess abnormalities in red blood cell parameters, iron metabolism, and vitamin B12 status in children with obesity, and to evaluate the influence of dietary intake and obesity-related complications on these variables. Methods: A retrospective analysis was conducted in 152 children with obesity. Anthropometric, biochemical, and hematological parameters were assessed. Dietary intake was evaluated in a subgroup of 33 participants using 3-day food records. Results: No cases of low hemoglobin levels were identified. However, elevated TIBC and occasional low ferritin levels suggested disturbances in iron metabolism. BMI Z-score was positively associated with red blood cell count and selected iron metabolism markers, whereas higher body fat percentage was negatively associated with hemoglobin and hematocrit. Dietary analysis indicated that protein and vitamin B12 intake were associated with erythrocyte parameters, while no associations were found for iron or folate intake. Elevated liver enzymes were associated with higher hemoglobin, hematocrit, and MCV values. Conclusions: Pediatric obesity was not associated with low hemoglobin levels but may be linked to early, subclinical disturbances in iron metabolism. These findings should be confirmed using more comprehensive biomarkers. Dietary factors, particularly vitamin B12 intake, may contribute to variability in erythrocyte parameters; however, these associations should be interpreted with caution. The observed relationship between liver function and erythrocyte indices warrants further investigation.