Ventilatory function, height, and mortality among lifelong non-smokers.

STUDY OBJECTIVE The aims were to determine the relationship between spirometric indices and mortality among lifelong non-smokers, and to investigate whether the association of short stature with increased risk of death is explained by reduced levels of ventilatory function in shorter men. DESIGN The study was a nested (within cohort) case-control analysis of an 18 year prospective study of mortality. SUBJECTS Participants were 3452 male civil servants aged 40-64 years at entry who denied ever having smoked tobacco. MEASUREMENTS AND MAIN RESULTS 408 men who died were matched to 2874 controls of the same age and height. Reduced one second forced expiratory volume (FEV1) was associated with mortality from non-respiratory causes (rate ratio per litre decrease = 1.44, 95% confidence interval 1.196-1.73). The ratio of FEV1 to forced vital capacity was a weak predictor of mortality. Among 397 case-control sets matched for age and FEV1, mortality was unrelated to height. Comparing mortality differentials across age adjusted tertiles of each risk factor, height adjusted FEV1 was a stronger predictor of death than height, body mass index, or plasma cholesterol. FEV1 adjusted for age but not for height was almost as strong a predictor as systolic blood pressure. CONCLUSIONS The determinants of ventilatory function in lifelong non-smokers may include causes of premature death. FEV1 may be a more sensitive indicator than height of early life influences upon mortality.