Effect of long-term therapy with oral steroids on respiratory muscle function and ventilatory drive

E. Zanotti, R. Corsico, C. Rampulla, N. Ambrosino, C. Fracchia, P. Crotti, F. Rubini, S. Nava

Research output: Contribution to journalArticlepeer-review


It has been shown that chronic oral steroid therapy (ST) does not induce respiratory muscle dysfunction in normal and asthmatic subjects. As corticosteroids are sometimes chronically used in the treatment of the patients with chronic obstructive pulmonary disease (COPD), the aim of our study was to verify whether ST could cause respiratory muscle impairment and, since ST also affects the central nervous system, whether ST could influence the ventilatory pattern. We retrospectively studied 12 COPD patients (group A), on long-term therapy (for at least 4 consecutive months, range 4-18 months) with an oral steroid, deflazacort, 15 mg·d-1. The subjects were strictly matched, with regard to age, sex, height, weight, forced expiratory volume in one second (FEV1), residual volume (RV), arterial oxygen tension (PaCO2), arterial carbon dioxide tension (PaCO2) and pH, with 12 COPD patients (Group B) who had never taken oral steroids. To assess respiratory muscle strength, we measured maximal inspiratory (MIP) and expiratory (MEP) pressures, while mouth occlusion pressure (P0.1) was employed to assess neuromuscular drive; ventilatory pattern and airway impedence were also evaluated. Effectiveness of ST was confirmed by the plasmatic levels of endogenous cortisol. No significant differences were observed between the two groups with regard to MIP (A 72.2 ± 9.7 vs B: 70 ± 7.2 cmH2O) and MEP (A 91.6 ± 10.5 vs B 94.4 ± 7.6 cmH2O) whilst P0.1 was significantly higher in group A (2.6 ± 0.3 cmH2O) than in group B (1.8 ± 0.1 cmH2O). No significant differences were found among all the ventilatory parameters, but the impedence was significantly higher in group A. Chronic administration of oral steroids in COPD patients, at relatively low doses, does not affect respiratory muscle strength, whilst increasing the neuromuscular drive.

Original languageEnglish
Pages (from-to)16-22
Number of pages7
JournalMonaldi Archives for Chest Disease - Cardiac Series
Issue number1
Publication statusPublished - 1993


  • airway impedance
  • airway occlusion pressure
  • corticosteroids
  • maximal expiratory pressure
  • maximal inspiratory pressure

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Pulmonary and Respiratory Medicine


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