Validity of Different Anthropometric Indices in the Assessment of Body Composition of Children and Adolescents with Type 1 Diabetes

Background: The prevalence of overweight and obesity in young people with type 1 diabetes (T1D) has been increasing despite current advancements in the management of T1D. Objectives: This study aimed to assess the prevalence of overweight/obesity using bioelectrical impedance analysis (BIA) in children and adolescents with T1D and evaluate the validity of new anthropometric indices, which have been recommended for defining overweight and obesity. Methods: A cross-sectional study was performed on subjects with T1D between the ages of 5 and 21 years. The patients'anthropometric measurements were obtained, and Body Mass Index (BMI), waist/height ratio (WHtR), Tri-Ponderal Mass Index(TMI), Body Adiposity Index (BAI), Body Shape Index (ABSI), Body Roundness Index (BRI), Abdominal Volume Index (AVI), andConicity Index (CI) were calculated. The percentage of body fat (PBF) was measured with BIA. Results: Our study included 133 subjects (48.1% male, 77.4% pubertal) with a median age of 14.0 years (11.3 - 16.5) and a medianduration of T1D of 4.5 years (1.5 - 7.3). The prevalence of overweight/obesity was 21.8% according to BMI-SDS and 30.1% according toBIA. BMI-SDS, WC, WHtR, TMI, AVI, BRI, and BAI were effective methods in differentiating overweight/obesity. BMI-SDSdemonstrated a sensitivity of 78.79%, a positive predictive value of 72.22%, a negative predictive value of 89.71%, and an AUC of0.895 at a cut point of 0.63, highlighting its effectiveness in distinguishing overweight/obesity. Conclusions: In children and adolescents with T1D, the prevalence of obesity/overweight identified using BIA was significantlyhigher compared to BMI-SDS. When reference methods are unavailable, BMI-SDS is the optimal anthropometric method fordetermining overweight/obesity in this population, independent of sex and puberty. These findings suggest that BMI-SDS can bea reliable alternative for body composition assessment, ensuring accurate identification and management ofoverweight/obesity in this population.