Unspecific bronchial reactivity to carbachol in healthy subjects--effect of age and smoking habits

Respiration. 1994;61(4):199-203. doi: 10.1159/000196337.

Abstract

Chronic inflammatory processes of the airways induced by long-time cigarette consumption are a crucial factor in the pathogenesis of chronic obstructive pulmonary disease. In contrast, the role of cigarette smoking in the pathogenesis of bronchial hyperreactivity (BHR) is still unclear. The aim of this study was to assess the effect of chronic cigarette consumption on pulmonary function tests and BHR in healthy subjects. 63 healthy smokers and 63 lifetime nonsmokers matched for sex, age, height and weight were evaluated. Pulmonary function was determined by body plethysmography and spirometry. Bronchial provocation was performed by inhalation of increasing doses of carbachol (up to 25 g/l) in isotonic NaCl solution. Pulmonary function tests were within normal limits in all subjects. Nevertheless, midexpiratory flow at 25% of forced vital capacity was significantly smaller, and functional residual capacity was significantly greater in middle-aged smokers (age: 40-60 years) compared to middle-aged nonsmokers (p < 0.05, both comparisons). In young smokers and nonsmokers (age: 20-30 years) pulmonary function tests were not different (p > 0.28, all comparisons). Importantly, the carbachol concentration that provoked a 50% rise in specific airway resistance (PD50sRaw) was similar in smokers and nonsmokers of both age groups (p > 0.05, both comparisons) and did not correlate with the age of the subjects (p > 0.2). No correlations between baseline values of pulmonary function tests and PD50sRaw were observed (p > 0.34, all comparisons). The observations confirm that the distribution profile of BHR is unimodal and apparently not affected by age and smoking habits.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Age Factors
  • Airway Resistance / drug effects
  • Airway Resistance / physiology
  • Bronchial Hyperreactivity / physiopathology*
  • Bronchial Provocation Tests
  • Bronchoconstriction / drug effects
  • Carbachol*
  • Case-Control Studies
  • Female
  • Forced Expiratory Volume / drug effects
  • Forced Expiratory Volume / physiology
  • Functional Residual Capacity / drug effects
  • Functional Residual Capacity / physiology
  • Humans
  • Inspiratory Capacity / drug effects
  • Inspiratory Capacity / physiology
  • Male
  • Maximal Midexpiratory Flow Rate / drug effects
  • Maximal Midexpiratory Flow Rate / physiology
  • Middle Aged
  • Smoking / physiopathology*
  • Total Lung Capacity / drug effects
  • Total Lung Capacity / physiology

Substances

  • Carbachol