[Demographic and regional determinants of underweight in Polish teenagers]

The aim of the study was to examine the prevalence of underweight in Polish teenagers in demographic and regional context. The examination was conducted in 5 regions in Poland, in a representative cohort of 8067 13-15 years pupils in 112 lower secondary schools. The measurements of body height and mass were taken and body mass index (BMI) was calculated in all participants. Pupils with BMI value below 5 percentile of sex-specific growth charts were categorized as underweight. In statistical analysis was used multivariate logistic regression and chi-square test with SPSS v.14 application. The prevalence of underweight in pupils was 4,2%, more prevalent in boys than girls, younger pupils (13 years) than older (15 years). The prevalence of underweight pupils was almost the same in urban and rural area. We found regional differences in prevalence of underweight in examined pupils. The highest prevalence was found in Kujawy region, and the lowest in Podlasie. In the last decade the prevalence of underweight in this population increased approximately 2--4% between 1995 and 2005, with retaining the same regional differences. Results of our study show that regional factors (ethnic, cultural) play more important role than urbanization in prediction prevalence of underweight in adolescents in Poland.