Growth Acceleration in Japan as Indicated by the Maximum Growth Age in Height

Verification Regarding Secular Trend of Height Growth and The Maximum Peak Velocity during Adolescence

“…This affirmed the report of Kudo et al (1976), but did not demonstrate the rapid delay of the age at MPV in the wartime period because Kudo et al (1976) performed analysis by dividing the secular trend into prewar and postwar periods. The present study was conducted over 30 years after the study of Kudo et al (1976) conducted in 1976, so could examine the secular trend after that, and determined MPVs by applying the WIM to the cohort datasets. Thus, the present study demonstrated phenomena of the rapid delay of the age at MPV and the acceleration of the MPV from 1940 through 1946.…”

“…There are a few reports on analysis of secular trend of age at MPV. As an example of studies that calculated age at MPV in an expedient manner, Kudo et al (1976) analyzed the secular trends of maximum growth age (MGA) from 1900-1974 by using their own original method that calculated MGA. In this report, they divided the secular trend into prewar and postwar periods and analyzed them by applying a regression line to the prewar period and Gompertz and logistic curves to the postwar period.…”

“…In this regard, the present study should be of significance. Kudo et al (1976) fitted Gompertz and logistic curves to rapid lowering tendencies of age at MPV. In the present study, however, the age at MPV in boys did not exhibit a smooth transition like these curves but exhibited a gradual lowering tendency after a rapid delay, whereas that in girls exhibited a transition like a sextic least square approximation polynomial.…”

“…In other words, the catch-up phenomenon is a growth acceleration phenomenon. Regarding the essentiality of this phenomenon, Kudo et al (1976) reported that growth delay influenced by war and rapid growth acceleration toward recovery can be a model to clarify factors for the growth acceleration phenomenon. Although the extreme changes in lives of children and adolescents due to the war influenced their growth negatively, whether the bad conditions due to the war deranged the mechanisms of their height growth is unknown.…”

“…However, how lowering of the age at maximum growth velocity should be examined has not been clarified. Kudo et al (1976) and Takaishi (1979) determined age at maximum annual growth amount of height, i.e., age at maximum peak height velocity (PHV) during adolescence, and reported lowering of age at maximum growth velocity by analyzing the secular trend of that age. Years later, Kouchi (1996) reported upsizing of adult height and lowering of age at PHV in the context of a relationship between secular change of height growth and socioeconomic conditions.…”