The third examination of the original cohort was conducted in 1986-1987. The primary objective of the third examination was to assess the incidence of cardiovascular and pulmonary diseases for analyses relative to risk factor data and determine if the heritability of cardiovascular disease exceeded what was expected based on the known cardiovascular risk factors. Extensive pulmonary function testing was part of examination three as it was for examination two and provided longitudinal data for analyses of change in pulmonary function in relation to genetic and environmental factors. The exercise electrocardiogram was expanded to the entire cohort for examination three to provide additional data on sub-clinical disease.