Menarcheal age and endemic goitre.

A total of 13,566 school girls from 17 districts in Sri Lanka recalled their date of menarche for a study on the prevalence of goitre. Seventy-four percent (10,036) did not have any signs of goitre, and the recalled mean age of menarche for this group was 13.6 years. This figure was significantly lower than the mean age of 13.9 years observed in the goitrous group. The mean age was lowest for thyroid grade 0 and highest for thyroid grades 1b and above. The mean age in high prevalence areas was significantly higher both among goitrous and nongoitrous groups, and in different areas of prevalence the mean age was higher among the goitrous than the nongoitrous. These findings strongly suggest a delay in sexual maturation among girls living in endemic goitre areas and among girls with evidence of goitre.