Age at maturation, body structure and their relationship with socioeconomic factors.

In this study, we aimed to identify the differences in body structure between early, average, and late maturing girls, taking into account family characteristics assessing socio-economic and living conditions. This study was conducted in the years 2003 and 2013 in Warsaw, Poland and comprised 788 girls in the age group of 11-19 years. The data were collected using a questionnaire which included parental education and profession, girls' date of birth, age at menarche, and lifestyle characteristics. The measurements included height; weight; skinfolds on arm, under scapula, and on abdomen; arm circumference; and body mass index (BMI). The girls were divided into three groups: early, average, and late maturing. To eliminate the age differences, for each of the examined somatic variable, a "z" score was calculated. We analysed the combined data of both years (2003 and 2013) due to the lack of difference in the mean age at menarche. The primary objective of this study was to assess the relationship between somatic body structure and socioeconomic and lifestyle factors among early, average, and late maturing girls. Early maturing girls possessed higher body weight and BMI. In families with only one child, the age at menarche was found to be the earliest than in families with more than one child. Body weight, BMI, arm circumference, and fatfold thickness was found to be reduced in case of girls whose parents had better education and profession than their peers. Higher levels of stress were associated with higher body mass, greater BMI, arm circumference, and skinfolds in early maturing girls. The associations between body structure with physical activity and family was mainly correlated with body weight and BMI. Socioeconomic and lifestyle factors may be helpful in some levelling of differences in the body structure between girls differing in the age at menarche, especially the level of stress and the education and profession of parents.