Troyanov S, Ghezzo H, Cartier A, Malo J L
Department of Chest Medicine, Hópital du Sacré-Coeur, Montreal, Canada.
Thorax. 1994 Aug;49(8):775-80. doi: 10.1136/thx.49.8.775.
Most studies that describe circadian variations in asthma have used maximum rate of peak expiratory flow (PEF) rather than forced expiratory volume in one second (FEV1) to assess airway calibre. This study was designed to assess circadian variations in PEF and FEV1 measured simultaneously and to compare variations in these measurements in normal and asthmatic subjects in a stable clinical state.
Twenty nine subjects (nine asthmatic subjects on bronchodilators, 10 on inhaled steroids, and 10 normal controls) were asked to record their PEF and FEV1 with a new portable instrument every two hours during the day and once on waking at night for two weeks. Circadian variations were examined in different ways using arithmetical indices and cosinor analysis.
78% of PEF values and 75% of FEV1 values were considered to be reproducible and were included in the analysis. Variations obtained using PEF did not differ from those obtained using FEV1. Significant cosinor variations were found in at least 50% of recording days for most of the subjects and showed the same features as for arithmetical indices. Daily variations in PEF and FEV1 were significantly correlated with airway calibre and PC20 methacholine (r approximately 0.5 to approximately 0.6).
PEF is as satisfactory as FEV1 for describing circadian variations among normal subjects and stable asthmatic subjects.
大多数描述哮喘昼夜变化的研究使用呼气峰值流速（PEF）的最大速率而非一秒用力呼气量（FEV1）来评估气道口径。本研究旨在评估同时测量的PEF和FEV1的昼夜变化，并比较稳定临床状态下正常人和哮喘患者这些测量值的变化。
29名受试者（9名使用支气管扩张剂的哮喘患者、10名使用吸入性类固醇的患者和10名正常对照）被要求在白天每两小时使用一种新的便携式仪器记录一次PEF和FEV1，夜间醒来时记录一次，持续两周。使用算术指数和余弦分析法以不同方式检查昼夜变化。
78%的PEF值和75%的FEV1值被认为具有可重复性并纳入分析。使用PEF获得的变化与使用FEV1获得的变化没有差异。大多数受试者在至少50%的记录日中发现了显著的余弦变化，并且与算术指数显示出相同的特征。PEF和FEV1的每日变化与气道口径和乙酰甲胆碱PC20显著相关（r约为0.5至约0.6）。
在描述正常受试者和稳定哮喘患者的昼夜变化方面，PEF与FEV1同样令人满意。
