[Respiratory functional decline after 5 years in patients with silicosis and asbestosis]

A retrospective study of 561 patients with silicosis and 234 with asbestosis was performed to assess whether lung function decline in five years is related to the type (restrictive or obstructive) and/or to the degree of initial damage. Based on lung function tests, three groups of patients were identified: NC with normal lung function tests, CR with restrictive impairment and CO with airway obstruction. The degree of impairment was classified as mild, moderate and severe. Patients were considered worse if five years later they presented a higher degree of impairment. The prevalence of CR was significantly higher in asbestosis, that of NC and CO in silicosis (p less than 0.01). Among subjects with normal starting lung function, 9% only developed CR or CO 5 years later. The prevalence of subjects with worsened lung function in the CR groups was significantly higher (p less than 0.001) in asbestotics (36%) than in silicotics (14%) and was closely related to starting functional impairment. In the CO group the prevalence of worsened subjects was significantly higher than in CR (p less than 0.001), similar in the two diseases and independent of starting lung impairment.