Increased body mass index is related to apparent circumscribed pleural thickening on plain chest radiographs

Background Diffuse pleural thickening and pleural plaques are the commonest radiological manifestations of asbestos exposure. Differentiation between subpleural fat and non-calcified pleural plaques is important clinically an d medico-legally. This study aims to determine if apparent circumscribed pl eural thickening on chest radiographs is related with obesity. Methods Surveillance chest x-rays of 693 former asbestos workers were read with the ILO classification. Subjects with costophrenic angle obliteration (n = 57) were analyzed separately. The remaining subjects were subdivided a ccording to their body mass index (BMI): Group 1 <26 kg/m(2); Group 2 26-30 kg/m(2); Group 3 >30 kg/m(2). Results Baseline characteristics, asbestos exposure, and profusion scores w ere evenly distributed. BMI of > 30 kg/m(2) was associated with a higher pr evalence of pleural thickening on CXR (Gp1 = 8.5%; Gp2 = 9.3%; Gp3 = 18.3%) . This relationship was strongest in the subgroups with 25-50% of the later al chest wall involved and pleural thickness of < 10 mm. Conclusion Obesity (BMI > 30 kg/m(2)) is related to apparent circumscribed pleural thickening on CXR, especially thin (< 1 cm) shadows covering 25-50% of the lateral chest wall. Am. J. Ind. Med. 39:112-116, 2001. (C) 2001 Wil ey-Liss, Inc.