WAIST-TO-HEIGHT RATIO IS AN IMPORTANT ANTHROPOMETRIC DISCRIMINATOR OF METABOLIC DISORDERS IN OVERWEIGHT AND OBESE ADOLESCENTS: A PILOT STUDY
Authors:   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia, Bairova T.A. , Balzhieva V.V. ,   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia, Ayurova Zh.G. ,   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia, Mikhalevich I.M. ,   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia, Paramonov A.I. ,   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia, Rychkova L.V. ,   Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia
Published: October 2022

The purpose of the research was to describe the most informative anthropometric indicator for identifying a metabolically unhealthy phenotype in Caucasian adolescents with overweight and obesity. Materials and methods of the research: single-center cross-sectional study. The studies were carried out in Feb. 2015 - Oct. 2016 in the regions Republic of Buryatia and Irkutsk Oblast. At the first stage, the study included data from 1356 adolescents aged from 10 years to 17 years 11 months 29 days old obtained during a dispensary examination: anthropometric examination and determination of the level of blood glycemia. The second stage, which includes lipid profile analysis, calipometry and measurement of circumferential parameters, included adolescents with overweight and obesity, adolescents with a morning glycemia level exceeding 5.6 mmol/l, and adolescents who wished to participate in the study and met the inclusion criteria. A total of 219 children were included in the study: 99 (45.2%) boys (age 13 [12-15]) and 120 (54.8%) girls (age 14 [12-16]). There was no statistically significant age difference between boys and girls (p=0.093). Results: when comparing the analyzed parameters in the group of adolescents with overweight and obesity, but with different metabolic phenotypes, statistically significant differences were revealed: waist circumference (WC)/height ratio - 0.54 [0.50:0.58] in boys without metabolic disorders vs. 0.58 [0.54:0.62] with metabolic disorders (p=0.042); roundness index - 4.08 [3.30:4.92] vs. 4.97 [4.13:5.78], respectively (p=0.042); hip volume - 97.64 [92.25:98.75] versus 99.15 [97.00:99.80], respectively (p=0.040). In girls, a similar pattern of differences in anthropometric parameters in the sample of girls without metabolic disorders and with those: WC/height - 0.52 [0.47:0.59] vs. 0.60 [0.54:0.69] (p=0.012); roundness index 3.78 [2.92:5.13] vs. 1.19 [1.14:1.29] (p=0.039). When comparing anthropometric parameters in adolescents with normal weight, but with different metabolic phenotypes, no statistically significant differences were found. The most informative parameters of the metabolically unhealthy phenotype in both boys and adolescent girls are the WC/height ratio and roundness index. Threshold values for predicting metabolic unhealthiness in boys are WC/height ratios greater than 0.53 (AUC=0.69, 95% Cl=0.54-0.84, sensitivity=0.632, specificity=0.731), roundness index greater than 3.96 (AUC=0.69, 95% Cl=0.54-0.84, sensitivity=0.632, specificity=0.731); in girls -WC/height ratio greater than 0.50 (AUC=0.75, 95% Cl=0.60–0.90, sensitivity=0.833, specificity=0.670), roundness index greater than 3.38 (AUC=0.75, 95 % Cl=0.60-0.90, sensitivity=0.833, specificity=0.670). Both parameters were calculated using WC and height, but the complexity of calculating the roundness index (in the absence of an available Russian-language online calculator) compared to calculating the WC/height ratio makes it difficult to use in clinical practice. Conclusion: the WC/height ratio in both boys and girls is the best indicator in clinical practice for verifying a metabolically unhealthy phenotype in overweight and obese adolescents. The optimal threshold value of this indicator for predicting two or more components of metabolic disorders that are not related to WC is 0.50 in girls and 0.53 in boys.