Third Department of Internal Medicine, Wakayama Medical University, Japan.
Allergol Int. 2010 Dec;59(4):363-7. doi: 10.2332/allergolint.10-OA-0197. Epub 2010 Aug 25.
The measurement of the exhaled nitric oxide fraction (FE(NO)) is proposed as a useful marker of airway inflammation. In healthy adults, there have been a few studies of the reference ranges for FE(NO) in Caucasians. A community study in other regions may reveal any possible ethnic differences in the FE(NO) levels.
A total of 240 healthy adults aged between 18 to 74 years were recruited from four medical centers in Japan. Current smokers and subjects having a history of atopic disease were not included. FE(NO) was measured using an online electrochemical nitric oxide analyzer according to the current guidelines. The reference ranges for FE(NO) were estimated using two different statistical methods recommended by International Federation of Clinical Chemistry and Laboratory Medicine.
The mean FE(NO) was 16.9 ppb (parts per billion) with a 95% prediction interval (2.5 to 97.5 percentiles) of 6.5 to 35.0 ppb in healthy Japanese adults. Normality assumptions were met for the logarithm-transformed FE(NO). The geometric mean FE(NO) was 15.4 ppb with a mean ± two standard deviations of 6.5 to 36.8 ppb. Age, gender, height, and past smoking history were not associated with the FE(NO) levels.
The reference ranges for FE(NO) in healthy Japanese adults were similar to those of Caucasians. It seems reasonable that the upper limit of FE(NO) for healthy adults should be set at approximately 36.0 ppb irrespective of ethnic differences.
呼气一氧化氮分数（FE(NO)）的测量被认为是气道炎症的有用标志物。在健康成年人中，已经有一些关于白种人 FE(NO)参考范围的研究。其他地区的社区研究可能会揭示 FE(NO)水平方面的任何种族差异。
共有 240 名年龄在 18 至 74 岁之间的健康成年人从日本的四个医疗中心招募。不包括当前吸烟者和有特应性疾病史的受试者。FE(NO)使用在线电化学一氧化氮分析仪根据当前指南进行测量。FE(NO)的参考范围使用国际临床化学和实验室医学联合会推荐的两种不同统计方法进行估计。
健康日本成年人的平均 FE(NO)为 16.9 ppb（十亿分之一），95%预测区间（2.5 至 97.5 百分位）为 6.5 至 35.0 ppb。对数转换后的 FE(NO)符合正态分布假设。FE(NO)的几何平均值为 15.4 ppb，平均值±两个标准差为 6.5 至 36.8 ppb。年龄、性别、身高和过去的吸烟史与 FE(NO)水平无关。
健康日本成年人的 FE(NO)参考范围与白种人相似。无论种族差异如何，将健康成年人的 FE(NO)上限设定在约 36.0 ppb 似乎是合理的。
