Age at menarche: secular trends and association with adult anthropometric measures

Background: Age at menarche has been used as a marker of environmental cond itions during childhood. Previous work has shown trends of decreasing age a t menarche throughout the 19th century, but reported trends in the 20th cen tury have been less consistent. The nature of the relationship between age at menarche and adult life anthropometric measures may be important in unde rstanding the importance of this measure on disease in later life. Aim: To establish whether mean age at menarche changed during the first hal f of the 20th century, and to determine the nature of associations between age at menarche and anthropometric measures in young adulthood. Subjects and methods: 3433 female students, who were born between 1919 and 1952 and who attended health checks at the student health service of the Un iversity of Glasgow between 1948 and 1968. Results: Mean age at menarche decreased from 13.2 years in the earliest bor n to 12.5 years in the latest born students. These results were not explain ed by changes in socio-demographic factors. Menarcheal age was positively a ssociated with height and negatively associated with weight and BMI, result s independent of socio-demographic and behavioural factors. Conclusions: The falling age at menarche described here may be related to n utritional influences in the first half of the 20th century. The influence of menarche on BMI in early adulthood may have important health consequence s.