Rosenfeld Margaret, VanDevanter Donald R, Ren Clement L, Elkin Eric P, Pasta David J, Konstan Michael W, Morgan Wayne J
Department of Pediatrics, Seattle Children's Hospital, University of Washington School of Medicine, Seattle, Washington.
Case Western Reserve University School of Medicine, Cleveland, Ohio.
Pediatr Pulmonol. 2015 Sep;50(9):856-62. doi: 10.1002/ppul.23227. Epub 2015 Jun 18.
Despite the attention paid to minimizing lung function decline among cystic fibrosis (CF) patients, the effect of rate of decline on subsequent disease progression is poorly understood. We aimed to describe the rate of decline of FVC, FEV1 , and FEF25-75 and to test the hypothesis that rate of decline of each spirometric variable predicts subsequent rate of decline in that variable and each other variable.
Data were from the Epidemiologic Study of CF, an observational study of North American CF patients from 1994 to 2005. For each year of age, patients' best percent predicted FEV1 and associated FVC and FEF25-75, were used to calculate 2-year slopes for each spirometric variable. Pearson correlations were calculated between reference slopes and follow-up slopes up to 8 years later and, for FEV1 , between reference slopes and level (not slope) of lung function up to 5 years later.
Twenty six thousand, three hundred and ninety-three patients contributed 427,063 spirometries. Median 2-year slopes of all variables were negative for all ages >6 years and the magnitude varied with age, being greatest among 13-17 year olds, especially for FEF25-75 . There was no correlation (r < 0.10) between reference slopes and subsequent slopes 3-8 years later, either within or across variables. The correlation between 2-year FEV1 slopes and FEV1 level even 5 years later was moderate (0.37-0.49) across disease stage categories.
Contrary to our hypothesis, rate of lung function decline did not predict future rate of decline either within or across spirometric variables. In contrast, FEV1 slope did have moderate predictive ability for subsequent FEV1 level. These findings are relevant for clinical care and for clinical trial design.
尽管人们关注尽量减少囊性纤维化（CF）患者的肺功能下降，但下降速率对后续疾病进展的影响却知之甚少。我们旨在描述用力肺活量（FVC）、第1秒用力呼气容积（FEV1）和呼气流量峰值（FEF25-75）的下降速率，并检验以下假设：每个肺量计变量的下降速率可预测该变量及其他变量随后的下降速率。
数据来自CF流行病学研究，这是一项对1994年至2005年北美CF患者的观察性研究。对于每个年龄组，使用患者预测FEV1的最佳百分比以及相关的FVC和FEF25-75来计算每个肺量计变量的2年斜率。计算参考斜率与长达8年后的随访斜率之间的Pearson相关性，对于FEV1，计算参考斜率与长达5年后的肺功能水平（而非斜率）之间的相关性。
26393名患者提供了427063次肺功能测定数据。所有年龄大于6岁的患者，所有变量的2年斜率中位数均为负值，且幅度随年龄变化，在13 - 17岁患者中最大，尤其是FEF25-75。在3 - 8年后，无论是在变量内部还是变量之间，参考斜率与后续斜率之间均无相关性（r < 0.10）。在不同疾病阶段类别中，2年FEV1斜率与甚至5年后的FEV1水平之间的相关性为中等（0.37 - 0.49）。
与我们的假设相反，肺功能下降速率在肺量计变量内部或之间均不能预测未来的下降速率。相比之下，FEV1斜率对随后的FEV1水平具有中等预测能力。这些发现与临床护理和临床试验设计相关。
