Waist circumference, waist-to-hip ratio, and waist-to-height ratio reference percentiles for abdominal obesity among Macedonian adolescents

Background: the goal of this study was to define waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHRt) smoothed reference percentiles for assessing abdominal obesity in Macedonian adolescents aged 11 to 18 years in order to investigate possible obesity cut-offs of WHR and WHtR, and to compare WC percentiles with those of other adolescents. Methods: the research was conducted on a sample of 2,490 adolescents of the Republic of Macedonia aged 11 to 18 years: 1,288 males and 1,202 females. Weight, height, body mass index (BMI), WC, hip circumference (HC), WHR and WHtR were measured and percentiles were calculated using Cole's Lambda, Mu and Sigma (LMS) method. The relation between WHR, WHtR and general obesity, as defined by the International Obesity Task Force, was investigated with a receiver operating characteristic (ROC) analysis. Results: the boys had statistically significant higher values in all anthropometric measures except in HC, where statistically significant gender differences were not found. BMI, WC, and HC showed an increasing trend with age. The WHtR variable is a better indicator for assessing general obesity in both boys and girls (AUC, 95 % CI: 0.905-0.928) than WHR, which showed lower AUC values (95 % CI: 0.697-0.734) in predicting IOTF obesity; the WHtR cut-off of 0.5 had a sensitivity of 74 % and a specificity of 92 % for both genders and all age groups. Conclusions: the obtained reference percentile curves can be used temporarily for early detection of abdominal obesity among Macedonian adolescents aged 11 to 18 years; a WHtR of 0.5 may also be used as an obesity threshold in these age groups.