1. Response-Dose Ratio is a Surrogate of Cumulative Provocative Dosage for Bronchial Provocation Tests in Asthma
- Author
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Guan, Wei-jie, Zheng, Jin-ping, Shi, Xu, Xie, Yan-qing, Jiang, Cai-yu, Gao, Yi, Zhu, Zheng, An, Jia-ying, Yu, Xin-xin, and Liu, Wen-ting
- Subjects
Methacholine -- Research -- Health aspects ,Asthma -- Diagnosis -- Patient outcomes -- Care and treatment -- Research ,Health - Abstract
Background Response-dose ratio (RDR) and cumulative provocative dosage (PD) are useful indices reflecting airway responsiveness in asthma. Objectives To compare the diagnostic value of RDR and PD, by conducting leukotriene D.sub.4 (LTD.sub.4-BPT) and methacholine bronchial provocation test (MCh-BPT), in different asthma control levels. Methods Healthy subjects and asthmatic patients underwent LTD.sub.4-BPT and MCh-BPT, at 2-14-day interval. This entailed assessment of the distribution characteristics, correlation, and diagnostic value of PD inducing 20 % fall in forced expiratory volume in one second (PD.sub.20FEV.sub.1) and the RDR, defined as FEV.sub.1 fall (%) at the final step divided by the corresponding provocative dosage. Results Twenty uncontrolled, 22 partly controlled, 20 controlled asthmatics, and 21 healthy subjects were enrolled. Log.sub.10RDR was positively correlated with log.sub.10PD.sub.20FEV.sub.1 in both BPTs (all P < 0.05). Poorer asthma control was associated with significantly lower PD.sub.20FEV.sub.1 and higher RDR (both P < 0.05). The differences in PD.sub.20FEV.sub.1 and RDR between partly controlled and controlled asthma were unremarkable (both P > 0.05). Compared with log.sub.10PD.sub.20FEV.sub.1, the log.sub.10RDR yielded similar diagnostic values in both BPTs. A lower percentile of RDR (≤25th percentile) was associated with higher baseline FEV.sub.1 (P < 0.05) and an increased proportion of well-controlled asthmatic patients. The combination of RDR and PD.sub.20FEV.sub.1 led to an increased diagnostic value compared with either parameter alone. Conclusions RDR is a surrogate of PD.sub.20FEV.sub.1 for BPTs in asthma. This finding was not modified by different asthma control levels or the types of bronchoprovocants., Author(s): Wei-jie Guan[sup.1] , Jin-ping Zheng[sup.1] , Xu Shi[sup.1] , Yan-qing Xie[sup.1] , Cai-yu Jiang[sup.1] [sup.2] , Yi Gao[sup.1] , Zheng Zhu[sup.1] , Jia-ying An[sup.1] , Xin-xin Yu[sup.1] , Wen-ting [...]
- Published
- 2014
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