Aim of study: To verify the usefulness of Body Mass Index (BMI) in the evaluation of expected body mass in girls with Turner's Syndrome (TS).
Material and methods: 36 girls with Turner's Syndrome aged 10-14 years took part in the study. Body height, body mass, sitting height and body fat content were measured, the latter by bioelectrical impedance method (Bodystat 5,000). Relative body fat content of TS girls was related to "normal" limits for healthy girls, determined for the purpose of this study.
Results: Compared to healthy girls, 50% of TS girls exhibited evaluated levels of body fat. Using BMI, only 14% of these girls were classified as overweight, 33% as "normal-weight" and 3% as undernourished. Similar misclassification was observed in case of TS girls with reduced body fat (8%), all of them being classified by BMI as having normal body mass. Significant correlation (r = -0,707) was found between body fat content and sitting height.
Summary and conclusions: It seems unjustified to use BMI in the evaluation of normal body mass in girls with TS as it does not reflect the relative body fat content. The observed misclassification of the BMI and bioelectrical impedance method may be also due to abnormal body proportions of TS girls.