Population, Policy and Practice Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.
Growth and Development Department, Hospital Garrahan, Buenos Aires, Argentina.
Ann Hum Biol. 2021 Feb;48(1):8-14. doi: 10.1080/03014460.2021.1883109. Epub 2021 Mar 23.
Children with achondroplasia (ACH) appear to lack a pubertal growth spurt in height. To explore the growth spurt in height and its segments sitting height and leg length, in a large sample of ACH cases using growth curve modelling. Height and sitting height were measured longitudinally in ACH children, and the data were analysed using the SITAR (SuperImposition by Translation and Rotation) growth model, which estimates a mean growth curve and random effects for individuals defining differences in size, pubertal timing and intensity. Out of 402 ACH children, 85 boys and 75 girls aged 7-20 years had respectively 529 and 454 measurements of height and sitting height, with leg length calculated by difference. SITAR analysis identified peaks in mean height velocity at 13.3 and 11.3 years in boys and girls, with peak velocities of 4.3 and 4.4 cm/year. Mean peak velocity for sitting height was 3.0 cm/year, but leg length showed no peak. The SITAR models explained 92% to 99% of the cross-sectional variance. ACH children do experience a growth spurt in puberty, but only half that of control children. The spurt is due entirely to sitting height, with no leg length spurt.
患有软骨发育不全症（ACH）的儿童似乎在身高上缺乏青春期生长突增。为了探讨大量 ACH 病例中身高生长突增及其分段坐高和腿长，我们使用生长曲线模型进行研究。对 ACH 儿童进行了身高和坐高的纵向测量，并使用 SITAR（平移和旋转叠加）生长模型对数据进行了分析，该模型估计了个体的平均生长曲线和随机效应，以定义大小、青春期时间和强度的差异。在 402 名 ACH 儿童中，85 名男孩和 75 名女孩分别有 529 次和 454 次身高和坐高测量，腿长通过差值计算。SITAR 分析确定了男孩和女孩身高速度的平均峰值分别为 13.3 岁和 11.3 岁，峰值速度分别为 4.3 和 4.4cm/年。平均坐高峰值速度为 3.0cm/年，但腿长没有峰值。SITAR 模型解释了 92%至 99%的横断面方差。ACH 儿童确实在青春期经历了生长突增，但只有对照组儿童的一半。突增完全是由于坐高的增加，而腿长没有突增。
