Figure 4

The Ve spectrum in volunteers by age was similar regardless of technique. As expected, Ve values were significantly higher in older subjects with significant comorbidity. Ve data from either the infusion technique (Panel A) or the bolus technique (Panel B) yielded similar linear regression results where both techniques detected significantly higher Ve with increasing age. When the same Ve data were then sorted in order of ascending Ve (sorted by Ve from infusion technique in Panel C; sorted by Ve from bolus technique in Panel D), both techniques identically sorted the older subjects with higher mean Ve (dashed boxes). Error bars in the bar graphs indicate the standard error of the mean for repeated Ve measures by each technique in each individual.