Forty years trends in timing of pubertal growth spurt in 157,000 Danish school children

• Published in: PloS one Vol. 3; no. 7; p. e2728
• Main Authors: Aksglaede, Lise, Olsen, Lina W, Sørensen, Thorkild I A, Juul, Anders
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16-07-2008; Public Library of Science (PLoS)
• Subjects: Adolescent; Adolescent Development; Age; Algorithms; Body Height; Body Weight; Breast cancer; Child; Child Development; Children; Children & youth; Chronology; Cohort Studies; Denmark; Diabetes and Endocrinology/Endocrinology; Diabetes and Endocrinology/Reproductive Endocrinology; Elementary school students; Famine; Female; Girls; Growth; Health care; Health problems; Humans; Male; Maturation; Measurement methods; Medical screening; Pediatrics; Pediatrics and Child Health/Adolescent Medicine; Pediatrics and Child Health/Child Development; Physiological aspects; Preventive medicine; Puberty; Race; Reproduction; Reproductive health; Reproductive systems; Software; Studies; Time Factors; Trends; Velocity; World War II; Denmark; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0002728

Entering puberty is an important milestone in reproductive life and secular changes in the timing of puberty may be an important indicator of the general reproductive health in a population. Too early puberty is associated with several psychosocial and health problems. The aim of our study was to determine if the age at onset of pubertal growth spurt (OGS) and at peak height velocity (PHV) during puberty show secular trends during four decades in a large cohort of school children.
Annual measurements of height were available in all children born from 1930 to 1969 who attended primary school in the Copenhagen Municipality. 135,223 girls and 21,612 boys fulfilled the criteria for determining age at OGS and age at PHV. These physiological events were used as markers of pubertal development in our computerized method in order to evaluate any secular trends in pubertal maturation during the study period (year of birth 1930 to 1969). In this period, age at OGS declined statistically significantly by 0.2 and 0.4 years in girls and boys, respectively, whereas age at PHV declined statistically significantly by 0.5 and 0.3 years in girls and boys, respectively. The decline was non-linear with a levelling off in the children born between 1940 and 1955. The duration of puberty, as defined by the difference between age at OGS and age at PHV, increased slightly in boys, whereas it decreased in girls.
Our finding of declining age at OGS and at PHV indicates a secular trend towards earlier sexual maturation of Danish children born between 1930 and 1969. Only minor changes were observed in duration of puberty assessed by the difference in ages at OGS and PHV.