Summary:A semi-longitudinal study in 111 healthy school children, 11 years old, was started in May 1976 to evaluate age-related "normal-ranges" of two so-called "routine" tyood parameters during adolescence. Follow-up examinations were performed at one-year intervals until 1982. In this paper growth velocity is described and results of estimations of alkaline phosphatase, inorganic phosphorus (Pj) and total calcium (Ca) are presented and compared with values in the literature.Peak growth velocity in girls (5.94 ± 1.92 cm/year) occurred between 11 and 12 years, in boys (7.73 ± 2.4 cm/year) between the age of 12 and 13 years; from the age of 14 years onwards boys were significantly taller than girls. A strong relationship (p < 0.05) between growth and alkaline phosphatase could be shown throughout the period observed. Alkaline phosphatase activity varied within a wide ränge and reached mean peak values at the age of 11 years in girls (470.9 + 114.8 U/l) and the age of 13 in boys (514.4 ± 135.7 U/l), Afterwards, alkaline phosphatase activity decreased towards adult levels. Inorganic phosphorus constantly decreased in both boys and girls until the age of 16, while from the age of 16 to 17 years a significant increase could be observed in both sexes. Total calcium values showed a significant increase between 12 and 13 years in boys and between 13 and 14 years in girls; after the age of 14 values decreased significantly in both sexes. Our data strongly support the assumption that the known changes of alkaline phosphatase and Pj are mainly due to growth and pfobably secondarily due to sex hormone changes. Änderungen der alkalischen Phosphatase, des anorganischen Phosphors und des Calciums im Serum gesunder i i-bis 17jähriger Jugendlicher und deren Bezug zum Wachstum

From May 1976 until June 1982 a longitudinal study in 54 apparently healthy Austrian schoolchildren with a mean age of 11.2 years at their first visit was performed. The aim of this study was to determine if there are any age-related changes in serum lipids, lipoproteins and α-tocopherol concentrations during adolescence and whether a permanent relationship between lipoproteins and α-tocopherol can be observed. Total cholesterol showed a significant decrease from age 11 to 14 years in boys (from 195.5 ± 42.2 to 147.9 ± 40.3 mg/dl) as well as in girls (from 181.9 ± 29.7 to 144.1 ± 23.4 mg/dl); thereafter, a slight increase could be shown. Similar changes could be observed for LDL cholesterol. No significant sex differences were found either in total or in LDL cholesterol, whereas in HDL cholesterol concentrations, a decrease in boys between 12 and 14 years (from 58.4 ± 18.3 to 41.7 ± 10.8 mg/dl) and an increase in girls from 13 years onwards led to significantly lower values in boys than in girls from the age of 16 years onwards. No consistent changes could be shown for α-tocopherol blood levels. Nevertheless, a close relationship between total cholesterol and α-tocopherol could be observed during all our investigations (0.4695 ≤ r ≤ 0.7300, p < 0.05) and, to a lesser degree, between LDL cholesterol and α-tocopherol. Significant correlations between α-tocopherol and HDL cholesterol and between α-tocopherol and triglycerides occurred only occasionally.