論文

査読有り
2017年9月6日

Usefulness of the desaturation-distance ratio from the six-minute walk test for patients with COPD

International Journal of COPD
  • Yukari Fujimoto
  • ,
  • Yutaro Oki
  • ,
  • Masahiro Kaneko
  • ,
  • Hideki Sakai
  • ,
  • Shogo Misu
  • ,
  • Takumi Yamaguchi
  • ,
  • Yuji Mitani
  • ,
  • Hisafumi Yasuda
  • ,
  • Akira Ishikawa

12
開始ページ
2669
終了ページ
2675
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.2147/COPD.S143477
出版者・発行元
Dove Medical Press Ltd.

Purpose: A straightforward, noninvasive method is needed to assess emphysema and pulmonary hypertension (PH) in COPD patients. The desaturation-distance ratio (DDR) is an index derived from the distance traveled and level of desaturation during a six-minute walk test (6MWT)
it has previously been shown to be associated with percentage of forced expiratory volume in the first second of expiration (%FEV1.0) and percentage of diffusion capacity of the lung for carbon monoxide (%DLCO). The aim of this study was to examine the associations between DDR and emphysema and PH. Patients and methods: We collected the following data for 74 stable COPD outpatients: lung function tests (%FEV1.0 and %DLCO), 6MWT distance and desaturation, and area of emphysema on computed tomography (percentage of low attenuation area). Enlargement of the pulmonary artery (PA) was assessed by the ratio of the diameter of the PA to that of the aorta (PA:A ratio) as an index of PH. DDR was calculated by the distance traveled and the degree of desaturation reached during a 6MWT. The relationships between study outcomes were assessed with Spearman’s rank-correlation analysis. Receiver operating characteristic (ROC) curves were used to determine the threshold values with the optimum cutoff points for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA. Results: DDR correlated significantly with %FEV1.0, %DLCO, %LAA, and PA:A ratio. DDR showed high accuracy (area under the ROC curve.0.7) for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA. Conclusion: The results suggest that DDR is a good index of emphysema and PH in COPD patients. The 6MWT is widely used to assess COPD, and DDR could help with the early diagnosis of COPD.

リンク情報
DOI
https://doi.org/10.2147/COPD.S143477
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/28919734

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