Longitudinal versus cross-sectional vital capacity changes and affecting factors.
Forced vital capacity (VC) and forced expiratory volume at 0.75 s (FEV) were measured in 592 Cretan island men aged 25 to 74 in 1960, 1965, and 1970. Vital capacity and FEV were directly correlated with height, but percentage changes were unrelated to height. A prominent accelerating decrease with age was also observed, the longitudinal decrement becoming more marked with advancing age. Chronic obstructive lung disease at entry significantly accelerated the loss of lung capacity, more so for emphysema than for chronic bronchitis. Among heavier men, body weight gains intensified the age-dependent loss of vital capacity and FEV. Borderline statistically significant differences in FEV decreases (adjusted for age, height and entry FEV) were seen between cigarette smoking groups. Heavy smokers had more diagnoses of chronic bronchitis and emphysema. Modifiable factors in minimizing the decrease of lung capacity with age include obesity, obstructive lung disease, and smoking, the last through development of chronic obstructive lung disease.