Composicion corporal a la menarca. Estimacion del peso corporal total, del agua corporal total, del peso corporal magro y graso / [Body composition at menarche. Estimation of total body weight, total body water, lean and fat body weight]

Our aim was to confirm in our environment what has been observed and described by other writers about the importance of achieving a [quot ]critical body weight’’ and an adequate [quot ]fat percentage’’ -on the basis of the calculation of total body water- for the initiation and development of pubertal events. This study included 92 girls, healthy, well nourished, belonging to upper middle class from a high school of The National University of Cordoba. The longitudinal method of control was used every 6 months and at the precise moment of menarche. Out of 20 antropometrical variables observed height, weight and height, TBW as percentage of body weight, lean body and fat weight, fat percentage and skin folds ppercentiles for each girl at menarche. A regression between fat percentage and skin folds was done. Percentiles 5 to 95 of fat percentage in relation to body water percentage were estimated. At menarche the average for the different variables are: Heigth 155.6 cm +/- 0.469; Weight 45.8 Kg +/- 0,5; TBW 25.216 lit. +/- 0.318; lean body weigth 35.02 Kg (S.D.2.98); fat weigth 10.86 Kg (S. D. 3.17). The addition of skin folds was correlated fat percentage, thus, an equation was obtained for the average calculation of such percentage

F= 12.16 + (0.313 x fold addition). The minium percentage for the onset of menstrual cycles is 17.3

and corresponds to percentile 10. However, there is a 5

of girls who start to menstruate with a 15.5

of fat and none of them is below that value. The reasons mentioned above suggest that is necessary to obtain a [quot ]critical body weigth’’ as well as a [quot ]fat percentage’’ minimum for the onset and maintenance of menstrual cycles, among our girls, similar o what has been obtained by doctor Frisch.

Evolucion antropometrica de la talla, peso y agua total corporal pre- y post-menarca / [Anthropometric evolution of height, weight and total body water pre and post menarche]

The aim of the survey was to assess the anthropometric evolution of height, weight and total body water 1 year prior and until 1 year after the menarche in a higher middle level scholar adolescents group from a double-time secondary school belonging to Cordoba National University. A longitudinal study of 48 adolescents was performed. The control was made every six months and at the time of menarche, Twuenty anthropometric variables were relieved from which height and weight were used, the total body water (TBW) was determined by Mellits and Cheek equation and biological maturation was assessed according to Tanner criteria. Height and weight, and total body water increase pre- and post-menarche was determined, with +/- 1SD, as well as the average of studied variables +/- 1 SD. Height and weight increase was of 7.813 cm (+/-1.61) and 7.488 Kg(+/-2.3) respectively 12 months prior menarche, with a major speed in the first semester. After menarche, in the following months, height as much as weight increase, more the former than the latter, but there is less increase than in the year previously to menarche. The increase in the 12 posterior months has an average of 3.48 cm(+/-1.18) for height and 2,524 Kg(+/-1.90) for weight, with a major speed in the first semester. Likewise, the total body water decrease as an index of the body fat and is inversely correlated with the increase of weight in fat. We conclude that these results are perfectly correlated with the studied biological phenomenon, according to patterns described by other authors in other countries with different racial features. The onset of menarche is a good parameter to predict, rather approximately, without using another estimates, the final height in a girl.