Secular trend of the skeletal maturation in relation to peak height velocity-a comparison between two groups of children born 1969-1973 and 1996-2000.

Abstract

The aims were to study the presence of a secular trend in (a) age at peak height velocity (PHV), (b) velocity at PHV, and (c) duration of skeletal maturation in relation to PHV. Two groups of children: 100 children (63 boys, 37 girls) born between 1969-1973 and 71 children (49 boys, 22 girls) born between 1996 and 2000, were compared. Age and velocity at PHV were measured on individual growth velocity curves. Skeletal maturation stages were assessed on hand-wrist radiographs, and duration from the skeletal maturation stages to PHV was determined. Age at PHV occurred significantly earlier (0.47 years, CI 95% 0.19-0.76, P < 0.001), and velocity at PHV was significantly higher (0.68 cm/year, CI 95% 1.47-2.06, P < 0.003) in children born 1996-2000 compared to 1969-1973. No significant difference in duration of skeletal maturation was seen between the groups. Skeletal maturation stages occurred significantly in the following order before PHV for both genders: PP2= 2.18 years (P = 0.002), MP3= 1.60 year (P = 0.008), S 1.07 year (P = 0.003), and MP3cap 0.38 year (P = 0.037). Most radiographs were taken before PHV, the duration thus mainly reflects the early event of pubertal growth spurt. A secular trend was evident: significantly decreased age at PHV and significantly increased velocity at PHV. No evidence of a secular trend regarding duration of the skeletal maturation in relation to PHV was found. Due to the declining age at PHV, the skeletal maturation stages occurred earlier in relation to chronological age.