Performance of triponderal mass index, body mass index z scores, and body mass index performance in the diagnosis of obesity in children and adolescents

Objectives: Childhood obesity is a global health problem that affects millions of children and causes obesity-related adverse health outcomes in both childhood and adulthood. Although body mass index (BMI) z scores and percentiles are used in the diagnosis of obesity in children, it has been emphasized in recent years that the triponderal mass index (TMI) may be more accurate for this purpose. We aimed to compare TMI with BMI in the diagnosis of obesity in Turkish children and adolescents. Methods: The records of 3540 children who applied to Gulhane Training and Research Hospital were retrospectively scanned and the data of 1161 children were included in the study. The body fat percentage (BF%) was calculated by a formula, and children with body fat in the >= 95th percentile were classified as obese. Receiver study characteristics analysis was performed to compare the effectiveness of TMI and BMI in the diagnosis of obesity. Results: TMI correlated more with BF% (r = 0.863) than fat mass (r = 0.664); BMI correlated more with fat mass (r = 0.957) than BF% (r = 0.714) (P < 0.001). TMI had the highest area under the curve (AUC) in boys at diagnosis of obesity (6-11 y = 0.981; 12-15 y = 0.994). Girls ages 6 to 11 y had the same AUC for all 3 indexes (AUC = 0.977), whereas girls ages 12 to 15 y had the highest AUC for TMI (AUC = 0.967). However, the AUC values between all indices were very close. Conclusions: TMI can be used to diagnose obesity in Turkish children and adolescents in both boys and girls similarly and with good performance. The correlation with BF% and stability of TMI makes this index more advantageous. However, it should be noted that the performance of each of the 3 indices is very close to that of the others, and adjustments should be made according to age and sex. (C) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study compared the accuracy of three indices (body mass index, trunk mass index, and triponderal mass index) in diagnosing obesity in Turkish children and adolescents, using a sample of 1161. The results showed that the triponderal mass index had a higher correlation with body fat percentage and better performance. However, adjustments should be made according to age and sex.