Abnormal Liver Function Associated With Occupational Exposure to Dimethylformamide and Hepatitis B Virus

• Published in: Journal of occupational and environmental medicine 2001-05, Vol.43 (5), p.474-482
• Main Authors: Luo, Jiin-Chyuan, Kuo, Hsien-Wen, Cheng, Tsun-Jen, Chang, Ming J.W.
• Format: Article
• Language: English
• Subjects: Adult; Alcohol Drinking; Biological and medical sciences; Body Mass Index; Chemical and Drug Induced Liver Injury; Chemical and industrial products toxicology. Toxic occupational diseases; dimethylformamide; Dimethylformamide - adverse effects; Dose-Response Relationship, Drug; Hazardous materials; Hepatitis; Hepatitis B; Hepatitis B - complications; Hepatitis B virus; Humans; Liver; Liver - physiology; Liver Diseases - virology; Male; Medical sciences; Middle Aged; Occupational Exposure; Occupational hazards; ORIGINAL ARTICLES; Risk Factors; Solvents; Solvents - adverse effects; Toxicology; Viruses
• ISSN: 1076-2752; 1536-5948
• DOI: 10.1097/00043764-200105000-00008

N,N-Dimethylformamide (DMF) has excellent solvent properties and is used intensively in the production of synthetic leather and resins. It has caused hepatoxicity in human and animal studies. Hepatitis B virus (HBV) and hepatitis C virus infections are reported to be the major causes of chronic liver diseases (including liver cirrhosis and liver cancer) in Taiwan. This study examined the dose-response relationship of the observed abnormal liver function among the DMF-exposed workers and the interactions among DMF, other chemical exposures, HBV infection, and potential confounders on liver abnormalities. The average DMF exposure concentration was 11.6 ppm (median, 5.9 ppm; range, 0.1 to 86.6 ppm); 65 of 176 workers (36.9%) had high (>10 ppm) DMF exposure, 37 (21 %) had middle (>5 ppm, ≤10 ppm) exposure, and 74 (42%) had low (≤5 ppm) exposure. There were 24 of 65 abnormal liver function test results (LFTs) (36.9%) (elevations of either glutamate oxaloacetate transaminase glutamate pyruvate transaminase, or gamma-glutamyl transpeptidase) among the workers with high DMF exposure, 10 of 37 abnormal LFTs (27%) among workers with middle DMF exposure, and 11 of 74 abnormal LFTs (22%) among workers with low DMF exposure. Compared with the workers having low DMF exposure, the HBV, dunking, body mass index (BMI), sex, duration of employment, epichlorohydrin, and toluene exposure adjusted odds ratios (ORs) (and 95% confidence intervals [CIs]) for abnormal LFTs were 1.62 (0.61, 4.28) for workers with middle DMF exposure and 2.93 (1.27, 6.8) for those with high DMF exposure, and there was a significant dose response between DMF exposure and the prevalence of abnorm LFTs (P = 0.006). There were significant associations between abnormal LFTs and HBV carriers (adjusted OR 3.11; 95% CI: 1.29, 7.5; P = 0.01) and between abnormal LFTs and increased BMI (adjusted OR: 2.2; 95% CI: 1.02, 4.72; P = 0.041). Ultrasonography showed significant associations between chronic liver diseases and HBV earner status, increased BMI and high cumulative (> 100 ppm-years) DMF exposure (respectively, adjusted OR: 9.58, 95% CI: 1.79, 51.4, P = 0.007; adjusted OR: 13.2, 95% CI: 1.32, 132, P = 0.025; and adjusted OR: 6.2, 95% CI: 1.14, 34.1, P = 0.032). Dunking and BMI were significantly associated with fatty liver (respectively, adjusted OR: 4.9, 95% CI: 1.39, 17.3, P = 0.012; and adjusted OR: 7.93, 95% CI: 1.6, 39.3, P = 0.01). In conclusion, this study demonstrated that (1) a significant dose-re