Endocrine Changes Before and After the Menarche

Abstract

Abstract. The study was carried out on healthy girls before and after the menarche in order to investigate the behaviour of certain hormones apparently affecting the growth spurt in puberty. It was desired to study the normal variation and to discover at what point of time the adult level is attained. The serum levels of growth hormone and alkaline phosphatase, and the urinary excreation of 17‐ketosteroids and 17‐hydroxycorticosteroids in a total of 146 healthy pre‐ and postmenarcheal girls were studied. The blood samples, one per girl, were collected in the afternoon after a moderate fast. The results were calculated for groups based on skeletal age, the so‐called gynecological age, and the stage of puberty. A review of the total group showed that alkaline phosphatase had a highly significant negative correlation to the skeletal age, height, weight and stage of puberty (r about −0.4). The 17‐ketosteroids and 17‐hydroxycorticosteroids were highly significantly positively correlated to the same variables (r about 0.4–0.5). The growth hormone correlation coefficients did not differ significantly from zero in this review. The alkaline phosphatase means were at their maximum at a skeletal age of 11 years and before secondary sex characters had appeared. After appearance of the latter the alkaline phosphatase values soon fell to the adult level. The growth hormone level was generally found to be significantly higher than in adult women. Girls with a bone age of 11–13 years had mean values significantly higher than the younger and the older girls. In groups based on the stage of puberty, the mean values were highest for the pubic hair stage 2 and breast stage 3, that is to say, before the menarche. The 17‐KS means were found to rise as the skeletal age increased. However, one year before and one year after the menarche the mean values were practically the same. The finding may suggest that there is a steady phase in the steroid production of the adrenal about the time of the menarche. Later the 17‐KS level showed a rise which seemed to continue even 5 years after the menarche. The values of 17‐OHCS in the pre‐menarcheal groups increased with skeletal age. The adult level was reached in the group with a skeletal age of 12 and puberty stage 3. The results suggest that, at the time of the growth spurt, the steroid secretion increases and the serum GH level rises. The high GH values accompany high alkaline phosphatase values but in a somewhat later phase of growth. In the 17‐ketosteroid excretion, a smooth increase continues until the menarche and, after a possible steady phase, the increase continues for years after menarche. For 17‐OHCS the adult level is reached before the menarche.