Data from: Concussion Biomarkers Assessed in Collegiate Student-Athletes (BASICS) I: normative study

Objective: To describe variability in concussion biomarker concentrations
collected from serum in a sample of healthy collegiate athletes, as well
as report reliability metrics in a subsample of female athletes. Methods:
Observational cohort study - Aβ42, total tau, S100B, UCH-L1, GFAP, MAP2,
and CNPase serum concentrations were measured in 415 (61% male, 40% white,
age 19.0±1.2 years) non-concussed collegiate athletes without recent
exposure to head impacts. Standardized normative distributions are
reported for each biomarker. We evaluated main effects (ANOVAs) of sex and
race, reporting demographic-specific normative metrics when appropriate.
In a subset of 31 female participants, test-retest reliability (Pearson’s
r) and reliable change indices (80%, 90%, and 95% confidence intervals)
across a 6-12 month interval are reported for Aβ42, total tau, S100B, and
UCH-L1. Results: Males exhibited higher UCH-L1 (p<.001, Cohen’s
d=0.75) and S100B (p<.001, d=0.56) than females, while females had
higher CNPase (p<.001, d=0.46). Regarding race, black participants
had higher baseline levels of UCH-L1 (p<.001, d=0.61) and S100B
(p<.001, d=1.1) than white participants. Conversely, white
participants had higher baseline levels of Aβ42 (p=.005, d=0.28) and
CNPase (p<.001, d=0.46). Test-retest reliability was generally
poor, ranging from -.02 – 0.40, and Aβ42 significantly increased from Time
1 to Time 2. Conclusion: Healthy collegiate athletes express
concussion-related serum biomarkers in variable concentrations. Accounting
for demographic factors like sex and race is essential. Evidence suggested
poor reliability for serum biomarkers; however, understanding how other
factors influence biomarker expression, as well as knowledge of reliable
change metrics, may improve clinical interpretation and future study
designs.

研究目标：描述健康大学生运动员样本中血清来源的脑震荡相关生物标志物浓度的变异性，并报告女性运动员亚组的可靠性指标。
研究方法：本研究为观察性队列研究。纳入415名近期无头部撞击暴露史的无脑震荡大学生运动员，其中男性占61%、白人占40%，年龄为19.0±1.2岁；检测其血清中Aβ42、总tau、S100B、UCH-L1、GFAP、MAP2及CNPase的浓度。报告各生物标志物的标准化参考分布特征。采用方差分析（Analysis of Variance, ANOVA）评估性别与种族的主效应，并在适宜情况下报告人口统计学特征特异性的参考标准值。在31名女性参与者组成的亚组中，报告间隔6至12个月的重测信度（皮尔逊相关系数r）及可靠变化指数（80%、90%、95%置信区间），涉及生物标志物包括Aβ42、总tau、S100B及UCH-L1。
研究结果：男性的UCH-L1（p<0.001，科恩d值=0.75）与S100B（p<0.001，d=0.56）水平高于女性，而女性的CNPase水平更高（p<0.001，d=0.46）。在种族差异方面，黑人参与者的UCH-L1（p<0.001，d=0.61）与S100B（p<0.001，d=1.1）基线水平高于白人参与者；反之，白人参与者的Aβ42（p=0.005，d=0.28）与CNPase（p<0.001，d=0.46）基线水平更高。重测信度整体较差，取值范围为-0.02至0.40，且Aβ42在时间1至时间2间显著升高。
研究结论：健康大学生运动员的脑震荡相关血清生物标志物浓度存在个体差异。需充分考虑性别、种族等人口统计学因素。现有证据显示血清生物标志物的信度整体较差，但明确其他因素对生物标志物表达的影响，以及掌握可靠变化指数相关知识，或可改善临床解读效果并优化未来研究设计。