TRACKING OF CARDIORESPIRATORY FITNESS FROM CHILDHOOD TO EARLY ADOLESCENCE: MODERATION EFFECT OF SOMATIC MATURATION

ABSTRACT Objective: To evaluate cardiorespiratory fitness’ tracking from childhood to adolescence, as well as to test the moderation role of somatic maturation. Methods: Our sample was composed by 375 children (197 boys), with a baseline age between 7 and 10 years old. The children were followed-up over three years. Body mass and stature were measured as anthropometric indicators and were used to estimate maturity status through Moore’s method. Cardiorespiratory fitness was evaluated through 9-minute running test. Body adiposity was estimated through the subcutaneous skinfold method, with measures of triceps and subscapular skinfolds and used as a covariate. Sample was categorized into tertiles. Thereafter, the Kappa (k) coefficient and Lin’s concordance correlation coefficient (LCCC) tests were adopted to verify stability. Dummy variable in regression was used to test moderation effects. All analyses were conducted in Stata 14.0, adopting p<0.05. Results: Cardiorespiratory fitness presented a moderate to low tracking from childhood to adolescence (k=0.294; LCCC=0.458). Moreover, maturity status significantly moderated the association between cardiorespiratory fitness at childhood and adolescence (regardless of cohort and body adiposity) among boys (β=0.644; p=0.003) and role sample (β=0.184; p=0.020), but not girls (-0.217; p=0.413). Conclusions: Tracking of cardiorespiratory fitness from childhood to adolescence is moderate to low in both sexes. Moreover, maturity status moderated the relationship between cardiorespiratory fitness at baseline and in adolescence. A lower age at peak height velocity was associated to a greater cardiorespiratory fitness.

摘要
目的：评估儿童至青少年时期心肺适能（cardiorespiratory fitness）的追踪稳定性，同时检验躯体成熟度的调节作用。
方法：本研究纳入375名儿童（其中男童197名），基线年龄为7~10岁，随访时长3年。以体质量与身高作为人体测量指标，通过摩尔法（Moore’s method）估算躯体成熟状态。采用9分钟跑试验评估心肺适能；通过肱三头肌与肩胛下皮褶厚度的皮褶测量法估算体脂含量，并将其作为协变量。将研究样本划分为三分位组，随后采用κ系数（Kappa coefficient）与林氏一致性相关系数（Lin’s concordance correlation coefficient, LCCC）检验追踪稳定性；通过回归分析中的虚拟变量检验调节效应。所有分析均采用Stata 14.0软件完成，检验水准设定为P<0.05。
结果：儿童至青少年时期的心肺适能追踪稳定性呈中低度水平（κ=0.294；LCCC=0.458）。此外，在不考虑队列与体脂含量的前提下，躯体成熟度对男童基线与青少年时期心肺适能的关联具有显著调节作用（β=0.644，P=0.003），对整体样本亦存在显著调节效应（β=0.184，P=0.020），但对女童无显著调节作用（β=-0.217，P=0.413）。
结论：男女儿童至青少年时期的心肺适能追踪稳定性均呈中低度水平。躯体成熟度可调节基线与青少年时期心肺适能之间的关联；身高突增峰值年龄越早，心肺适能水平越高。