Differences between remaining ability and loss of capacity in maximum aerobic impairment

Brazilian Journal of Medical and Biological Research. 1998;31(5):639-646

 

Journal Homepage

Journal Title: Brazilian Journal of Medical and Biological Research

ISSN: 0100-879X (Print); 1414-431X (Online)

Publisher: Associação Brasileira de Divulgação Científica

Society/Institution: Associação Brasileira de Divulgação Científica

LCC Subject Category: Medicine: Medicine (General) | Science: Biology (General)

Country of publisher: Brazil

Language of fulltext: English

Full-text formats available: PDF, HTML, XML

 

AUTHORS

Neder J.A.
Nery L.E.
Bagatin E.
Lucas S.R.
Anção M.S.
Sue D.Y.

EDITORIAL INFORMATION

Peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 22 weeks

 

Abstract | Full Text

In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classifications for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age >50 years (P<0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P<0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).