Objective: Childhood obesity is associated with an increased risk for insulin resistance. The underlying mechanism for the physiological increase in insulin levels in puberty is not clearly understood. The aim of the present study was to determine the cut−off values for homeostasis model assessment for insulin resistance (HOMA−IR) in obese children and adolescents according to gender and pubertal status.Methods: Two hundred and eight obese children and adolescents (141 girls, 127 boys) aged between 5 and 18 years were included in the study. The children were divided into prepubertal and pubertal groups. A standard oral glucose tolerance test (OGTT) was carried out in all children. A total insulin level exceeding 300 μU/mL in the blood samples, collected during the test period, was taken as the insulin resistance criterion. Cut−off values for HOMA−IR were calculated by receiver operating characteristic (ROC) analysis.Results: In the prepubertal period, the rate of insulin resistance was found to be 37% in boys and 27.8% in girls,while in the pubertal period, this rate was 61.7% in boys and 66.7% in girls. HOMA−IR cut−off values for insulin resistance in the prepubertal period were calculated to be 2.67 (sensitivity 88.2%, specificity 65.5%) in boys and 2.22 (sensitivity 100%, specificity 42.3%) in girls, and in the pubertal period, they were 5.22 (sensitivity 56%, specificity 93.3%) in boys and 3.82 (sensitivity 77.1%, specificity 71.4%) in girls.Conclusions: Since gender, obesity and pubertal status are factors affecting insulin resistance, cut−off values which depend on gender and pubertal status, should be used in evaluation of insulin resistance.Conflict of interest:None declared.

NC is a reliable and easy to use tool to determine overweight and obesity in children, and NC is not as good as WC in determining overweight and obesity, both providing similar information.

Abdominal obesity is associated with risk of cardiovascular disease and type 2 diabetes mellitus. Waist circumference as a measure of obesity may be clinically useful as a predictor of metabolic syndrome in children. To develop age- and sex-specific reference values for waist circumference we evaluated the data obtained from Turkish children and adolescents. Waist circumference measurements from 4,770 healthy schoolchildren were obtained. Smoothed percentile curves were produced by the LMS method. The median curves of Turkish children were compared with four other countries: Australia, the UK, USA (Bogalusa) and Japan. Smoothed percentile curves and values for the 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles were calculated for boys and girls. We found that waist circumference increased with age both in boys and girls. The 50th percentile waist circumference curve of Turkish children was over the British and Japanese but lower than the Bogalusa children and adolescents. This study presents data and smoothed percentile curves for waist circumference of healthy Turkish children aged 7-17 years. The differences in waist circumference of different countries can be explained by lifestyles and cultural characteristics. These data can be added to the existing international reference values for waist circumference of children and adolescents.

Objective: The purpose of this study was to determine the cut−off values for waist circumference (WC) and mid−upper arm circumference (MUAC) and to assess their use in screening for obesity in children.Methods: Anthropometric measurements of a total of 2621 boys and 2737 girls aged 6−17 years were analyzed. WC and MUAC values were compared with ROC analysis using body mass index (BMI) cut−off values of the International Obesity Task Force (IOTF) and using WC≥ 90th percentile.for MUAC.Results: In both genders, except for boys and girls in the 6−year age group and post−pubertal boys, the differences between area under curve (AUC) values for WC and MUAC were not significant, indicating that both indices performed equally well in predicting obesity. Sensitivity was suboptimal through age groups 6−9 years in the boys and sensitivity was suboptimal at 6, 7,14 and 17 years both in boys and girls.Conclusions: We conclude that MUAC can be a useful parameter in screening obesity and body fat distribution in children and, can be applied in epidemiological studies and in clinical practice.Conflict of interest:None declared.

Neck circumference measurement was shown to be associated with cardiometabolic risk factors in children. We suggest the use of neck circumference as a novel, simple, practical and reliable anthropometric index in predicting children at risk for cardiometabolic diseases.