Transfer factor, lung volumes, resistance and ventilation distribution in healthy adults

Abstract

Monitoring of chronic lung disease requires reference values of lung function indices, including putative markers of small airway function, spanning a wide age range.We measured spirometry, transfer factor of the lung for carbon monoxide (TLCO), static lung volume, resistance and ventilation distribution in a healthy population, studying at least 20 subjects per sex and per decade between the ages of 20 and 80 years.With respect to the Global Lung Function Initiative reference data, our subjects had average z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC of −0.12, 0.04 and −0.32, respectively. Reference equations were obtained which could account for a potential dependence of index variability on age and height. This was done for (but not limited to) indices that are pertinent to asthma and chronic obstructive pulmonary disease studies: forced expired volume in 6 s, forced expiratory flow, TLCO, specific airway conductance, residual volume (RV)/total lung capacity (TLC), and ventilation heterogeneity in acinar and conductive lung zones.Deterioration in acinar ventilation heterogeneity and lung clearance index with age were more marked beyond 60 years, and conductive ventilation heterogeneity showed the greatest increase in variability with age. The most clinically relevant deviation from published reference values concerned RV/TLC values, which were considerably smaller than American Thoracic Society/European Respiratory Society-endorsed reference values. @ERSpublications We present reference equations for median and variability of most lung function indices, in the age range 20-80 years http://ow.ly/SsZFW

Peripheral airway dysfunction and relationship with symptoms in smokers with preserved spirometry

“…We studied smokers <50 years of age who had smoked between 8 and 40 pack‐years. Limiting the study to young subjects avoided the potential confounding effects of age on Sacin, which becomes much more variable over the age of 60 years . We limited the study to 40 pack‐years or less since we reasoned that young individuals who had smoked >40 pack‐years and had normal spirometry, would be unlikely to develop COPD and could also be less likely to have peripheral airway abnormalities.…”

“…Limiting the study to young subjects avoided the potential confounding effects of age on Sacin, which becomes much more variable over the age of 60 years. 41 We limited the study to 40 pack-years or less since we reasoned that young individuals who had smoked >40 pack-years and had normal spirometry, would be unlikely to develop COPD and could also be less likely to have peripheral airway abnormalities. The results of the present study therefore only apply to smokers under 50 years of age with <40 pack-years of smoking exposure.…”

Reference Values for Pulmonary Single-Breath Diffusing Capacity – Results of the “Study of Health in Pomerania”

“…Our results are in good agreement with current studies, especially with the global reference values for TL CO derived from the Global Lung Function Initiative in ▶ Table 2 Prediction equations for lung diffusing capacity for CO in men and women. 2017 [22,31,39]. The GLI (30) collected data from all normal value papers published since 2000 and analysed n = 9710 subjects.…”

Dismantling airway disease with the use of new pulmonary function indices

“…In contrast, in older people AHR is predicted by Sacin [78], suggesting the acinar rather than conductive airways contribute to ventilation heterogeneity in older people with asthma. It is worth noting that ventilation heterogeneity increases with age in health [79,80], with an accelerated increase seen in Sacin and LCI after the age of 60 years, versus a steady linear increase in Scond [80,81]. However, Sacin and LCI are both associated with loss of lung elastic recoil in elderly asthma independently of ageing [82].…”

“…For FOT, these have either only been collected in specific equipment [93], or there is an inability to pool data across multiple centres [94]. Similarly, reference values exist for MBNW only for specific equipment [60], some of which are custom built by specialised labs and, therefore, are not widely available [79,80].…”