GIRL BODY COMPOSITION ACCORDING TO PUBERTAL STATUS. METHODOLOGY VARIATION

Abstract

Objectives. During puberty, important somatic changes that alter body composition take place. In girls, the production of ovarian estrogen generates an important metabolic change. The objective of the present paper is to analyze the differences in body composition among pre and post-menarche girls of the same chronological age, studying the variations with different methodologies. Material and methods. The representative sample was composed of 249 schoolgirls, aged 12-13 years, who studied in "Tres Cantos" (Madrid). Two groups were formed with and without menarche (160 and 89). Body composition has been analyzed, using different methodologies: anthropometry and tetrapolar bioelectrical impedance. Population belongs to middle and upper middle class and there are no differences attributable to socio-economic situation. Results. The analysis shows significant differences in weight and height between pre or post-menarche girls, 41.2 ± 4.6 Kg versus 52.0 ± 6.6 Kg and 154.7 ± 6.4 cm versus 161.7 ± 5.4. According to Cole classification, both groups show a normal level of BMI, but the BMI of menarche girls was 19.89 ± 2.0 while that of no menarche girls was 17.21 ± 1.9. Body composition shows dramatically differences, the fat percentage was 13.8 ± 2.7 and 22.6 ± 5.9 in pre and post-menarche girls, with a decline of body water at the same age, water percentage being 64.7 ± 3.0 in pre-menarche subjects versus 57.7 ± 4.4 in those with menarche. Conclusions. The use of biological instead of chronological age is more useful in morphological studies and classifications among the pubertal stage population. The present study shows good correlation between the anthropometric method and bioimpedance to determine fat body composition.

Keywords

• bioelectrical impedance
• puberty
• body composition
• anthropometry
• girls