Effect of oxidative stress on development of silicosis

AIM: To investigate the changes of oxidative stress indicators in the serum of silicosis patients and explore the mechanism of silicosis development.METHODS: Two hundred workers who were exposed to silica dust for more than one year were recruited as dust-exposed group, 100 non-dust-exposed subjects served as control group, 32 patients with suspected 0⁺ silicosis as observation group, and 130 silicosis patients were taken as the silicosis group. Indicators of oxidative stress, including superoxide dismutase (SOD), nitric oxide (NO), serum glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), nitric oxide synthase (NOS), and lipid malondialdehyde (MDA), were determined in all the groups.RESULTS: Compared with the control group, NO and GSH-Px in dust-exposed group and silicosis group increased, and SOD decreased significantly (81.162 ± 35.176, 270.469 ± 39.228 and 68.209 ± 21.528, respectively, P = 0.004, P = 0.002, P = 0.005). Compared with the control and dust-exposed group, T-AOC, NOS and MDA in silicosis group increased significantly (13.048 ± 4.153, 36.201 ± 7.782 and 5.054 ± 1.204, respectively, P = 0.018, P = 0.022, P = 0.011). Compared with dust-exposed group, GSH-Px in the silicosis group increased significantly (270.469 ± 39.228, P = 0.002). GSH-Px in phase III silicosis was significantly higher than in phase I silicosis (290.750 ± 39.129, P = 0.021). Pearson correlation analysis showed that serum GSH-Px was positively correlated with silicosis staging, length of dust exposure and type of occupation (47.109 ± 8.015, P = 0.001).CONCLUSION: The imbalance of oxidative and anti-oxidation system is associated with the development of silicosis. The surveillance of oxidative stress indicators will benefit the prognosis of silicosis patients.