Cross-sectional reference values for height, weight and body mass index of schoolchildren living in Tehran, Iran

Abstract

The aim of the study was to create reference values for weight, height and body mass index (BMI) of school children living in Tehran. METHOD AND SAMPLES: The study subjects consisted of 1,420 girls between 6 and 17 years of age and 1,515 boys between 6 and 15 years of age. Samples were collected by a multistage sampling method from schools in different areas of Tehran. All participants were established to be healthy and their height, weight and BMI evaluated. Reference standard values estimated by the LMS method using LMS Light software and 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 97th and 85th (only for BMI) centiles were constructed and the results compared with US reference values. The centiles provided a good fit to the data. In boys, there were some significant differences of mean standard deviation scores (SDS) of height and BMI from zero, but there were no significant differences in weight. In girls, the mean SDS of height, weight and BMI were significantly lower than zero, especially for 7-9 years of age. Among 12-13-year-old girls, the mean SDS of height, weight and BMI came closer to zero, and the differences were not significant. Thereafter, although girls seemed to be shorter than US reference measures, their weight and BMI did not differ from reference values significantly. Our results for boys between 6 and 15 years are comparable with US reference values; however, the US reference values, especially for height, are not applicable for Iranian girls between 6 and 17 years.