Endocrine Abstracts

JOINT1901

Background: Obesity is a recognized risk factor for iron deficiency. Low-grade inflammation associated with obesity contributes to alterations in biomarkers of iron status. This study aimed to identify the best markers of adiposity and inflammation in relation to transferrin saturation (TS) and serum ferritin in a cohort of Belgian children and adolescents with overweight and obesity.

Methods: Data were retrieved from the medical records of 197 children with overweight/obesity at the start of a weight loss program. Iron status was assessed through measurements of serum iron, transferrin, TS, and ferritin. Inflammatory markers included serum high-sensitivity C-reactive protein (hS CRP) and plasma fibrinogen. Adiposity was evaluated using BMI SDS, waist circumference (WC) SDS, subscapular skinfold thickness (SST) SDS, waist-to-height Ratio (WHR), and body fat percentage (BF) by bioelectrical impedance analysis (BIA). TS was calculated as iron (µg/dl) *100)/(transferrin (g/l)* 127). Serum iron, transferrin, and ferritin levels were measured using the Cobas 8000 C702 platform. Stepwise multiple regression analysis was performed with TS and serum ferritin as dependent variables.

Results: Among the participants, 56% were male, 41% were prepubertal, and 80% had obesity (BMI SDS > 2). The median (Q1, Q4) age was 12.0 (10.5, 13.8) years, BMI SDS 2.3 (2.0, 2.6), WC SDS 2.2 (1.9, 2.4), SST SDS 2.0 (1.8, 2.2), BF 34% (32,39), WHR 0.57 (0.53, 0.60), serum iron 65 µg/dl (52, 88), TS 18% (14, 18), and plasma ferritin 44µg/l(30,71). Iron deficiency, defined as TS < 16%, was observed in 33.5 %, while 1.5 % had a low iron reserve, defined as a serum ferritin (< 7 µg/l). Elevated TS (> 45%) was rare (< 0.5%), as was increased serum ferritin (> 140 µg/l, 1.5%). TS was not associated with gender, age, or pubertal status but positively correlated with ferritin (Rho = 0.33; P < 0.001). In regression analyses, WC SDS (P = 0.01) and hS CRP (P = 0.03) were the primary predictors of TS, while fibrinogen was the sole predictor of serum ferritin (P = 0.04).

Conclusion: Iron deficiency, defined by low TS, affects one-third of Belgian children and adolescents with overweight/obesity. Waist circumference and hS CRP emerged as the key predictors of low TS, while elevated fibrinogen correlated best with increased serum ferritin. These findings underscore the importance of assessing low-grade inflammation when evaluating iron status among this population.