Age of onset of pubertal maturation of Thai boys.

BACKGROUND

Data regarding sexual maturation in Thai boys are limited to only one 1999 study done in Bangkok which found that the ages of onset of Tanner 2 testicular enlargement and pubic hair were 10.8 and 12.4 years, respectively.

OBJECTIVE

To determine the age of onset of pubertal maturation and the physical growth of Thai boys at Hat Yai municipality, southern Thailand, in the year 2012.

METHODS

A cross-sectional study was conducted in 1320 healthy boys, aged 6-19 years, during June 2011 to March 2012. Testicular volume and pubic hair development were assessed according to the Tanner staging method. Probit analysis was used to calculate the median age of different stages of testicular enlargement and pubic hair development.

RESULTS

The median ages of boys having Tanner 2 testicular enlargement and Tanner 2 pubic hair were 10.6 [95% confidence interval (CI), 10.4-10.7] and 12.0 (95% CI, 11.8-12.2) years, respectively. The youngest ages of boys who had Tanner 2 testicular enlargement and Tanner 2 pubic hair were 8.2 and 9.7 years, respectively. The final height was attained at age 18 years at 170.3 cm, 3.3 cm greater than the 167.0 cm final height of Hat Yai boys studied in 1994.

CONCLUSIONS

The age of onset of puberty in Hat Yai schoolboys in 2012 was 0.2 years earlier than that of Bangkok schoolboys in 1999. The final adult height of Thai boys increased 3 cm during the two decades.