Growth reference centiles and secular changes in Turkish children and adolescents

The purpose of the study is to develop current reference growth centiles for Turkish children and adolescents. A cross-sectional growth survey was conducted on 1.427 (709 boys and 718 girls) healthy schoolchildren aged 6-17 years in Ankara, the capital city of Turkey. As an indicator of socio-economic status, the occupation of the parents was recorded. Growth references of height, weight, body mass index (BMI), sitting height, iliospinal height, relative iliospinal height and relative sitting height were constructed by the LMS method. Sex differences, association of parental occupation with height and BMI standard deviation scores were assessed by analyses of variance. Results showed significant sexual dimorphism for height, weight, sitting height and iliospinal height (p<0.001). Significant effect of socio-economic background was found on height and BMI. The prevalence of overweight and obesity was found using the International Obesity Task Force (IOTF) reference criteria 22.4% and 5.6% in boys and 21.2% and 3% in girls. Present results demonstrated an increment during the last three decades in height, leg length and weight curves which is more prominent in boys, but not in the sitting height. This positive secular change appears to be a logical outcome of the gradual changes in nutrition, health care and education, and environmental and economic conditions.