The GRC-BLSA Program in Pulmonary Aging focused upon: a. Development of a Mathematical Model of Pulmonary Aging A new model of normal pulmonary aging is being developed based upon the change in physiologic emptying of the lungs. Digitized spirometry from BLSA healthy, nonsmokers, without evidence of heart disease, is converted into distributions of emptying times by moments analysis. Those healthy nonsmokers with minimal lung function decline will define the standard of optimal pulmonary aging. Aging of the lung will be defined as a significant increase beyond optimal in the proportion of ventilatory emptying described by long time constants. The age-related decline of individual pulmonary function may be described over longitudinal follow-up by a mixed-effects model which includes parameters for Intercept, Time Interval, (Time Interval)2, Age and Mean Emptying Time. b. Accelerated Decline in Pulmonary Function Predicts Coronary Heart Disease An accentuated risk for cardiac death follows a large decline in FEV1, independent of the effects of the initial FEV1% Predicted, cigarette smoking and other common CHD risk factors. There were 79 cases of CHD death and 804 survivors over the 1 to 28.5 year follow-up period. At study entry, cases were older, had a lower FEV1, a higher cholesterol level, a higher prevalence of hypertension and cigarette smoking. After adjusting for these factors in a Cox linear effects model, the most striking relative risks for cardiac mortality were associated with quintile of subsequent FEV1 decline. FEV1 decline increases with age, but at any age, successive increasing quintiles of FEV1 loss experienced 1.00, 2.92, 4.49, 5.13, and 3.27-fold excess risk of cardiac death. Significant association has been observed between rate of pulmonary function decline and the development of IHD.
