Results of Spirometry Among Individuals in a Silicosis Registry

Objective: To determine whether individuals with simple silicosis have obstructive and restrictive decrements. Methods: The prevalence of spirometric abnormalities by radiograph profusion, smoking, duration, and latency from first silica exposure was evaluated among confirmed silicotics. Results: Among 526 silicotics, 17.3% who had never smoked and 26.5% of smokers had obstruction, 30.1% and 28.1% had restriction, and 22.4% and 25.7% had a mixed obstructive and restrictive pattern. Individuals with category 3 profusion or progressive massive fibrosis were more likely to have abnormalities. Conclusion: Both obstructive and restrictive patterns were observed regardless of smoking status with a low profusion category of simple silicosis. There was an increased prevalence of restrictive changes with increased profusion. After controlling for age, smoking, and duration of exposure to silica, there was a statistically significant increased risk of obstructive and mixed changes with progressive massive fibrosis.