Longitudinal study of serum cholesterol, apolipoproteins and sex hormones during puberty.

In order to determine the age and sex dependency of some of the major risk factors for coronary heart disease during the period of sexual maturation a five-year longitudinal study was carried out on 105 boys and 133 girls living in Plzen, Czechoslovakia. Serum cholesterol was significantly elevated in 13-year-old girls (p less than 0.01), while no statistically significant sex-related differences in total and lipoprotein cholesterol and apolipoprotein A-I and apolipoprotein B levels were found in other age groups during the period of follow-up. In boys the total cholesterol showed a constant and statistically significant decrease (p less than 0.01) between the ages 11 to 13 years, but tended to rise during the last two years of study. In girls, serum cholesterol decreased significantly between the ages 11 to 15 years (p less than 0.05). A statistically significant decrease in pre-beta cholesterol was found in girls during puberty (p less than 0.05). The changes in beta lipoprotein cholesterol were similar to those for total cholesterol. The apolipoprotein A-I concentration decreased significantly between 11 and 15 years in boys (p less than 0.05), while it underwent no substantial change in girls. The apolipoprotein B level decreased permanently and significantly (p less than 0.05) during the 5-year period in girls. In boys, the concentration of this protein decreased between 11 and 14 years and increased during the 15th year when a value significantly higher than that for girls was attained (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)