Objective: Body mass index (BMI) and bioimpedance analysis (BIA) are reliable tools to assess nutrition. BIA evaluates body composition, which is related to health outcomes. This study aimed to examine the correlation between BMI z-score and BIA in children and to determine the contribution of BIA to the evaluation of malnutrition in children.Materials and Methods: This cross-sectional study included 307 participants. BMI and BIA (InBody 230) measurements were performed. We classified the participants according to their BMI z-scores. Demographic, laboratory, and BIA data were analysed. The Spearman test was performed to evaluate the correlation between BMI z-scores and BIA.Results: There were 153 (49.8%) females and 154 (50.2%) males, with a mean age of 10.6±2.9 years. Overweight-obese children had significantly higher BIA skeletal muscle mass (SMM) and fat mass (FM) ratios compared to Normal and Wasted-underweight classes. The BMI z-score showed a strong positive correlation with BIA FM (%) in both the 6-9-year-old (males: r=0.913, females: r=0.879) and the 10-15-year-old groups (males: r=0.885, females: r=0.884). In contrast, the BMI z-score had a moderate positive correlation with BIA SMM (%) in the 6-9-year-old group (males: r=0.574, females: r=0.675), which weakened in the 10-15-year-old group (males: r=0.330, females: r=0.508). The Overweight-obese Class had more micronutrient deficiencies and elevated insulin and uric acid levels.Conclusion: Although BIA SMM and FM results differed significantly among BMI z-score Classes classes, the correlation between BIA SMM and BMI z-score was not strong. Thus, BMI z-score had limitations in showing the body SMM ratio of children, especially of male adolescents. Nevertheless, BMI z-score showed a strong correlation with FM. Additionally, BMI z-score was not efficient in demonstrating micronutrient malnutrition.
Doğan et al. (Mon,) studied this question.