Data_Sheet_1_Secular trends in physical growth, biological maturation, and intelligence in children and adolescents born between 1978 and 1993.pdf

IntroductionHuman physical growth, biological maturation, and intelligence have been documented as increasing for over 100 years. Comparing the timing of secular trends in these characteristics could provide insight into what underlies them. However, they have not been examined in parallel in the same cohort during different developmental phases. Thus, the aim of this study was to examine secular trends in body height, weight, and head circumference, biological maturation, and intelligence by assessing these traits concurrently at four points during development: the ages of 4, 9, 14, and 18 years.
MethodsData derived from growth measures, bone age as an indicator of biological maturation, and full-scale intelligence tests were drawn from 236 participants of the Zurich Longitudinal Studies born between 1978 and 1993. In addition, birth weight was analyzed as an indicator of prenatal conditions.
ResultsSecular trends for height and weight at 4 years were positive (0.35 SD increase per decade for height and an insignificant 0.27 SD increase per decade for weight) and remained similar at 9 and 14 years (height: 0.46 SD and 0.38 SD increase per decade; weight: 0.51 SD and 0.51 SD increase per decade, respectively) as well as for weight at age 18 years (0.36 SD increase per decade). In contrast, the secular trend in height was no longer evident at age 18 years (0.09 SD increase per decade). Secular trends for biological maturation at 14 years were similar to those of height and weight (0.54 SD increase per decade). At 18 years, the trend was non-significant (0.38 SD increase per decade). For intelligence, a positive secular trend was found at 4 years (0.54 SD increase per decade). In contrast, negative secular trends were observed at 9 years (0.54 SD decrease per decade) and 14 years (0.60 SD decrease per decade). No secular trend was observed at any of the four ages for head circumference (0.01, 0.24, 0.17, and − 0.04 SD increase per decade, respectively) and birth weight (0.01 SD decrease per decade).
DiscussionThe different patterns of changes in physical growth, biological maturation, and intelligence between 1978 and 1993 indicate that distinct mechanisms underlie these secular trends.

引言
百余年来，人类的体格生长、生物学成熟度与智力水平均被长期观测呈现持续增长趋势。对比上述特征长期趋势的发生时序，可为探究其背后的潜在机制提供重要思路。然而，此前尚未有研究在同一队列的不同发育阶段对这些特征开展平行考察。因此，本研究旨在通过在发育进程的四个时间点（4岁、9岁、14岁及18岁）同步评估各项特征，探究身高、体重、头围、生物学成熟度与智力水平的长期变化趋势。

方法
本研究数据源自苏黎世纵向研究（Zurich Longitudinal Studies）的236名出生于1978至1993年的受试者，涵盖生长测量指标、作为生物学成熟度表征的骨龄数据，以及全量表智力测验结果。此外，本研究还将出生体重作为产前发育状况的表征指标进行分析。

结果
4岁时身高与体重的长期趋势为正向：身高每十年增长0.35个标准差（Standard Deviation，SD），体重每十年增长0.27 SD，该增长无统计学显著性。9岁与14岁时的变化趋势与之相似：身高每十年分别增长0.46 SD与0.38 SD，体重每十年均增长0.51 SD；18岁时体重仍呈现正向趋势（每十年增长0.36 SD），但身高的长期趋势不再显著（每十年增长0.09 SD）。
14岁时生物学成熟度的长期变化趋势与身高、体重相似，每十年增长0.54 SD；18岁时该趋势无统计学显著性（每十年增长0.38 SD）。
智力水平方面，4岁时呈现正向长期趋势（每十年增长0.54 SD）；与之相反，9岁与14岁时则呈现负向长期趋势（分别为每十年降低0.54 SD与0.60 SD）。
头围与出生体重在四个年龄点均未观察到显著长期趋势：头围每十年的变化量分别为0.01、0.24、0.17与-0.04 SD，出生体重每十年降低0.01 SD。

讨论
1978至1993年间，体格生长、生物学成熟度与智力水平的变化模式存在显著差异，这表明上述各类长期趋势的潜在作用机制各不相同。