Evaluation of the Discriminatory Abilities of Anthropometric Indices of Obesity in Prediction of Important Body Composition Parameters of Central Obesity CC01-CC04
Dr. Nazeem Ishrat Siddiqui,
2/3, North Bazaria, Ghafoor Iqbal Colony, Indore-6, Madhya Pradesh, India.
Introduction: Prevalence of obesity and its complications are reaching to epidemic proportions. For its early detection, various anthropometric indices like Waist Circumference (WC), Waist-To-Height Ratio (WHtR) and Conicity Index (CI) have been utilised.
Aim: To determine the discriminative abilities among anthropometric indices (WC, WHtR, CI) in predicting excess fatness.
Materials and Methods: Eighty seven (87) healthy adolescents of age between 17 to 25 years were enrolled for the study. Using standard protocol all the anthropometric and body composition parameters was recorded. Body Mass Index (BMI) was calculated by; Weight (kg)/Height (m2), Waist-to-Height ratio by dividing the waist circumference by the height and CI from mathematical equation CI=WC (m)/0.109vWeight (kg)/Height (m). Body composition parameters were determined using bio-impedance analysis technique.
Mean, Standard Deviation (SD) and correlation coefficient (r) was calculated. Receiver operating characteristic curve analysis was used to determine predictive abilities of the anthropometric indices of obesity.
Results: Body composition parameters have shown very strong correlation (p<0.0001) with all the indices of obesity. Waist to height ratio correlated maximally with total body fat (r=0.860) whereas waist circumference with body fat percent (r=0.867). CI has correlated maximally with body fat percent (r=0.503) followed by total body fat (r=0.464). BMI did not correlate with any of them. On comparison of AUC, Waist to height ratio and waist circumference has the highest percentage under curve for all the body composition parameters. Most accurate cut-off points of ROC curve revealed that WHtR, WC and CI at the cut-off value of 0.52, 87 cm and 1.3 (m2/3/kg1/2) respectively are better discriminators for all the body composition parameters.
Conclusion: Strong correlation exists between body composition parameters and anthropometric indices of obesity except BMI. Waist to height ratio, waist circumference and CI emerged as most sensitive and specific indices to predict body composition, comparable to the values obtained from BIA analysis. However, BMI should be used with caution in assessment of central obesity.