Determinants of relative skeletal maturity in South African children

Abstract

The variation of skeletal maturity about chronological age is a sensitive indicator of population health.Age appropriate or advanced skeletal maturity is a reflection of adequate environmental and social conditions, whereas delayed maturation suggests inadequate conditions for optimal development.There remains a paucity of data, however, to indicate which specific biological and environmental factors are associated with advancement or delay in skeletal maturity. The present study utilises longitudinal data from the South African Birth to Twenty (Bt20) study to indentify predictors of relative skeletal maturity (RSM) in early adolescence.A total of 244 black South African children (n=131 male) were included in this analysis. Skeletal maturity at age 9/10 years was assessed using the Tanner and Whitehouse III RUS technique.Longitudinal data on growth, socio-economic position and pubertal development were entered into sex-specific multivariable general linear regression models with relative skeletal maturity (skeletal age-chronological age) as the outcome.At 9/10 years of age males showed an average of 0.66 years delay in skeletal maturation relative to chronological age. Females showed an average of 1.00 year delay relative to chronological age. In males, being taller at 2 years (p<0.01) and heavier at 2 years (p<0.01) predicted less delay in RSM at age 9/10 years, independent of current size and body composition. In females, both height at 2 years and conditional weight at 2 years predicted less delay in RSM at 9/10 years (p<0.05) but this effect was mediated by current body composition. Having greater lean mass at 9/10 years was associated with less delayed RSM in females (p<0.01) as was pubertal status at the time of skeletal maturity assessment (p<0.01).This study identifies several predictors of skeletal maturation at 9/10 years, indicating a role for early life exposures in determining the rate of skeletal maturation during childhood independently of current stature.

Ethnic Differences in Peripheral Skeletal Development Among Urban South African Adolescents: A Ten-Year Longitudinal pQCT Study

“…White adolescents were also more likely than black children to have sustained a fracture by the age of 18 years . It has also been shown that there were ethnic differences in age at menarche and skeletal maturation in Bt20, which may contribute to differences in peripheral skeletal development . Skeletal maturation in black males was delayed by about 6 months compared to their white peers .…”

Use of backscattered scanning electron microscopy to quantify the bone tissues of mid‐thoracic human ribs

“…This is significantly later than in contemporary Western populations, wherein peak bone mass and density typically occur before the third decade of life at most skeletal locations (Baxter‐Jones, Faulkner, Forwood, Mirwald, & Bailey, ). Delayed skeletal maturation in the current study suggests inadequate conditions for optimal development (Hawley et al, ).…”

Accelerated skeletal maturation is associated with overweight and obesity as early as preschool age: a cross-sectional study

“…However, previous study participants were at puberty, and there was no evidence for the underlying mechanism of the association between obesity and accelerated SA in preschool children. To our knowledge, growth hormone and thyroid hormones play the main role in the growth of preschool children; GH acts mainly through IGF-1 [25,26]. Therefore, this study speculated that the interaction of growth hormone and IGF-1 might play the greatest role in accelerating skeletal maturation in preschool children with overweight and obesity.…”

“…Boeyer indicated that the initiation and completion of epiphyseal fusion occur at substantially younger ages in normally developing children born in 1995 than those born in 1935 (both male and female) [17]. These studies indicated that the secular trend of earlier maturation is attributed to the removal of growth constraints through improved nutrition, healthcare, and socioeconomic environments [26,31]. However, the participants in this study were below 6.5 years of age, and the result showed an overall average SA lower than CA, especially in children with normal-weight, at a rate of 64.7%.…”