Supranormal lung function: Prevalence, associated factors and clinical manifestations across the lifespan.

Abstract

It is now well established that there are different life-long lung function trajectories in the general population, and that some are associated with better or worse health outcomes. Yet, the prevalence, clinical characteristics and risk factors of individuals with supranormal FEV1 or FVC values (above the upper-limit of normal [ULN]) in different age-bins through the lifetime in the general population are poorly understood. To address these questions, we investigated the prevalence of supranormal FEV1 and FVC values in the LEAD (Lung, hEart, sociAl and boDy) study, a general population cohort in Austria that includes participants from 6 to 82 years of age. We found that: (1) the prevalence of supranormal pre-bronchodilator FEV1 and FVC values was 3.4% and 3.1%, respectively, and that these figures remained relatively stable through different age-bins except for participants >60 years., in whom they increased (5.0% and 4.2%, respectively). Approximately 50% of supranormal individuals had both increased FEV1 and FVC values; (2) supranormal spirometric values were consistently accompanied by higher static lung volumes and lower specific airway resistance through the lifespan, indicating better overall lung function; and (3) multivariate regression analysis identified that female sex, higher muscle mass (FFMI), less diabetes and fewer respiratory symptoms were consistently associated with supranormal FEV1 and FVC values. Supranormal FEV1 and/or FVC values occur in about 3% of the general population in different age bins and are associated with better health markers.