Spiroergometric parameters at maximal exercise testing assessed functional respiratory impairment in asbestos-induced fibrosis.

INTRODUCTION: Exercise intolerance is typical for asbestosis. We examined the correlation of spiroergometric parameters with severity of asbestosis according to the International Labour Office (ILO) classification. Patients were compared to a healthy control group. OBJECTIVES: Nineteen consecutive male patients with compensated asbestosis and 24 healthy subjects were examined. METHODS: All participants underwent pulmonary functional testing including maximal cardiopulmonary exercise testing (CPET). Results were compared to those of healthy subjects; the correlation to disease status was investigated. RESULTS: Significantly lower VCin , FVC, FEV1 , MEF50 , TLC and PaO2 at rest (P<0.001) were observed in asbestosis patients. Lower peak (weight-related) work rate (WR, WR/kg), (weight-related) oxygen uptake (V'O2 , V'O2 /kg), oxygen pulse (V'O2 /hr), ventilation volume (V'E ), carbon dioxide output (V'CO2 ) and blood lactate was associated (P<0.001) with more severe asbestosis according to the ILO-classification. Significant positive correlations (P<0.001) were seen for alveolar-arterial oxygen difference [P(A-a)O2 ] and PaCO2 . Multiple regression analysis revealed that asbestosis was the only significant factor associated with the spiroergometric parameters (P<0.001). A reduction of V'O2 , V'O2 /kg, V'O2 /hr, V'E , or V'CO2 at identical submaximal workload could neither be detected among the asbestosis severity nor in comparison to healthy subjects. Only the respiratory frequency was depending on severity of asbestosis. CONCLUSIONS: The severity of asbestosis correlates with maximal WR, V'O2 , V'O2 /hr, V'E and gas exchange. At identical workload the discrimination between patients and controls was only possible concerning the respiratory frequency. For detection of limitations in asbestosis patients, maximal CPET is recommended.

The validity of static lung compliance in asbestos-induced diseases.

BACKGROUND: Pulmonary compliance can be viewed as an indicator of distensibility of the lungs, not only in asbestos-induced pulmonary disorders but also in visceral pleural fibrosis extending into the lung parenchyma. In this study we evaluated static compliance measurements in asbestos-derived diseases, especially in patients with parietal pleura plaques. Lung function analyses, especially static lung compliance, were correlated with high-resolution computer tomography examinations. METHODS: Sixty-three patients with parietal pleural plaques, 10 with visceral pleural fibrosis, 39 with parenchymal pulmonary asbestosis together with parietal pleural plaques, and 42 with parenchymal pulmonary asbestosis together with visceral pleural fibrosis were enrolled in the study. RESULTS: In comparison with patients having only parietal pleural plaques, those having asbestosis and visceral pleural fibrosis showed significant decreases in static lung compliance, diffusing capacity, and vital capacity. Visceral pleural thickening was also associated with significantly reduced FEV(1), MEF(50), and FEV(1)/FVC ratios. Multiple regression analyses indicated that the existence of visceral pleural fibrosis (p = 0.017) is the most important factor accounting for a decrease in static compliance. Reference values of static lung compliance differ notably. In comparison with mean reference values, the sensitivity of detecting reduced lung compliance was calculated to be between 9.7 and 45.5 %. Other respiratory function variables failed to show any significant differences. CONCLUSION: Our data indicate that the measurement of static compliance is not sufficient for early detection of pulmonary function impairment in patients with parietal pleural plaques.

Asbestos exposure and malignant lymphoma: a multicenter case-control study in Germany and Italy.

AIMS: To analyze the relationship between asbestos exposure and malignant lymphoma in a multicenter case-control study conducted in Germany and Italy according to a common core protocol. METHODS: Male and female patients with malignant lymphoma (n = 1,034) between 18 and 80 years of age were prospectively recruited in six study areas in Germany (Ludwigshafen/Upper Palatinate, Heidelberg/Rhine-Neckar-County, Würzburg/Lower Frankonia, Hamburg, Bielefeld/East Westphalia, and Munich) and in two study areas in Sardinia, Italy (Cagliari and Nuoro provinces). A total of 1,173 population control subjects were drawn from population registers. In a structured personal interview, we elicited a complete occupational history, including every occupational period that lasted at least 1 year. On the basis of job task-specific supplementary questionnaires, trained experts assessed the exposure to asbestos. As a measure of cumulative asbestos exposure on a time by intensity scale, fiber-years were calculated. 12 cases (1.2%) and 12 control subjects (1.0%) had a cumulative asbestos exposure of more than 2.6 fiber-years (highest exposure category according to the 90th percentile of exposed control subjects). Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis adjusted for age, sex and study region. Patients with specific lymphoma sub-entities were additionally compared with the entire control group. RESULTS: We observed no statistically significant association between cumulative asbestos exposure and the risk of any lymphoma subtype. An elevated risk was found for the association between exposure to more than 2.6 fiber-years and multiple myeloma (OR = 6.0; 95% CI 1.4-25.1); however, numbers were small (n = 3 cases, all of them from Italy; n = 12 control subjects). CONCLUSIONS: Our study does not support an association between asbestos exposure and risk of malignant lymphoma.