The predictors of emphysema in South African gold miners.
Environmental and host factors have been implicated in the pathogenesis of emphysema. To assess the role of gold mining exposure (an environmental factor) and of various clinical features recorded early in a miner's career (host factors), a case control study was carried out as follows. From whole lung sections made routinely at all full autopsy examinations on South African gold miners, we selected 44 cases of emphysema and 42 controls without emphysema from among men 51 to 71 yr of age who died during 1980 and 1981. Exposure information was gathered and clinical records were reviewed for smoking history, symptoms, and the presence of rhonchi by decade before death. The presence and grade of silicosis (abstracted from the routine autopsy reports) was similar in both groups; so was bronchitis in the 49 cases and controls with histologic material adequate for review. However, cases were on average older, had worked more shifts in high dust, and had smoked more than controls; they had also exhibited symptoms and rhonchi more frequently before 1950, i.e., 30 yr before death. When these factors were examined in a multiple logistic regression analysis, shifts worked in high dust, smoking, and age were all shown to be strong and independent predictors of emphysema at autopsy; prediction, however, was not improved by addition of any of the clinical features examined. These findings agree with previous cross-sectional studies in South African gold miners showing an exposure response relationship between mining service and air-flow limitation measured by lung function tests in life.(ABSTRACT TRUNCATED AT 250 WORDS)