[Sex hormone changes during the prepubertal and pubertal development of healthy boy]

The size of testis, testosterone, LH, FSH were measured in 463 healthy boys, ages 5-18 years old. Our results showed that the values of the developmental indices increased with the age, and abruptly elevated at 13 years old indicating the beginning of puberty. At 17, all has indices had achieved the level of adulthood and did not further increase. It suggested the maturity of sex development at 17. The linear correlation analysis revealed a positive correlation between LH, FSH and testosterone (P less than 0.001, P less than 0.05-0.01, separately). The kinetic curves of LH and testosterone were also similar. The rise of LH preceded one age group than that of testosterone. The correlation between LH, FSH and testis size were positive correlation (before 14, P less than 0.001, P less than 0.01, separately; after 14, no significant difference in P values) and LH was positive correlation since 5 years old, but FSH was positive correlation since 7 years old. These finding suggest that the prepubertal testicular enlargement is primarily due to the action of LH and afterwards, FSH and testosterone combined with LH also contribute to the enlargement of testes. The clinical significance of sex hormone measurement was discussed.