The progressive effects of ageing on chemosensitivity in healthy subjects

SummaryThe aim of this study was to compare the central inspiratory drive (P0.1) response to hypoxia and hypercapnia between different age groups of elderly, nonsmoker, healthy subjects and young healthy controls.A random sample, proportionally stratified by age (65–69, 70–74, 75–79 and 80–84yrs) from a sample of nonsmoker elderly subjects representative of a general population and 47 healthy subjects aged 20–40 were selected. Arterial blood gas, lung volumes, diffusing capacity, maximal respiratory pressure and oxygen uptake measurements were performed. Breathing pattern and mouth occlusion pressure, as well as P0.1 responses to hyperoxic progressive hypercapnia and isocapnic progressive hypoxia were evaluated.The elderly subjects had lower P0.1 responses to hypoxia (0.017±0.006 vs. 0.031±0.008kPa/%, P