obesity, iron, chemical and liver diseases

• Main Authors: Tun-Jen Hsiao, 蕭敦仁
• Other Authors: Jung-Der Wang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/01274220009735224582

博士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 93 === Liver diease is a major leading cause of mortality in Taiwan. The number of died in liver diseases more than 10 thousand per year in this island. So how to lower the mortality rate of iver disease is our common direction of effort. In tradition, hospital and community are the main sites of liver disease prevention. But in worksites, the more stable and young workers make it an important and suitable site for the program of liver disease prevention if the administrators agree. There are many types of liver diseases, including viral hepatitis, non-alcoholic fatty liver disease, alcoholic liver disease, chemical and drug-induced liver injuries and their worse common outcomes- liver cirrhosis and hepatoma. Among the diversity of etiology of liver diseases, viral hepatitis has the worst health effect to victims; indeed, 80% of liver cirrhosis and 90% hepatoma related to the infection. Fatty liver is the most prevalent liver disease in Taiwan, the prevalence is about 21-25%, which is more than 15-20% of hepatitis B and 2-4% of hepatitis C. Although there is no national prevalence study of acoholic disease, the number of this kind of patients increased clinically. In that of drug-induced and chemical liver injury, the former only occur in occasional case reports, and the latter is the most important typr of liver disease which we should pay more attention to it in worksites. This report consists of the studies of workers of two different plants to determine the prevalence and risk factors of liver diseases. We also further investigate the mechanism and the effect body weight reduction in treatmentof the most prevalent fatty liver. This report is composed of 4 parts, the summaries are as below: Part I. Liver fibrosis in asymptomatic poly-vinyl chloride workers This study was designed to determine whether vinyl chloride monomer (VCM) exposure is associated with liver fibrosis. A total of 347 workers with occupational exposure to VCM were systemically examined using liver ultrasonography and routine liver function tests. Major findings were as below: 1. The prevalence of liver fibrosis in PVC workers was 5.8%. 2. Significantly increased risks of developing liver fibrosis were found in workers who had history of high exposure jobs, hepatitis B and/or C infection and body mass index greater than or equal to 25. Part II. Insulin resistance and ferritin as major determinants of nonalcoholic fatty liver disease in apparently healthy obese patients Two hundred and ten apparently healthy obese patients, aged from 18-65 years, with a body mass index (BMI) of 28 or more, were enrolled in a body weight reduction program in our hospital. All the subjects underwent screening and pre-program examinations including anthropometric data measurements, biochemistry testing, and ultrasonography of the liver. NAFLD was defined as fatty liver diagnosed by ultrasonograpgy plus persistent elevation of alanine aminotransferase (ALT) levels. The major findings were as below: 1. Fatty liver was found in only 80% (168/210) subjects with the risk factors of larger waist circumference and higher insulin resistacne. 2. Persistent ALT elevation was further detected in 25.6% (43/168) of subjects with the risk factors of higher serum ferritin level and insulin resistance. Part III. Effects of body weight reduction in obese subjects with NAFLD To assess the effect of body weight reduction in obese subjects with non-alcoholic fatty liver disease (NAFLD) and persistent elevated ALT. 54 patients were enrolled from our out patients department. These patients received 24 weeks of patial meal replacement with low calorie diet and exercise program. Fatty score from liver sonography were the sum score of liver-kidney contrast, masking of GB wall, blurring of portal vein, blurring of hepatic vein, and ultrasound far attenuation. 53 patietns completed the program.The major findings were as below: 1. The body weight reduction was 8.6 kgs on average, or 10.3% of initial body weight. 2. ALT was reduced from 92.7IU/L to 31.6 IU/L (p < 0.001). 37 (70%) out of the 53 patients had normal ALT value at the end of treatment. 3. The fatty scores of liver by ultrasound were reduced form 9.4 to 3.6 (p < 0.001). 4. The prevalence of metabolic syndrome was decreased from 41.5% to 11.3% after body weight reduction. 5. Linear mixed model analyses showed that within 24 weeks’ therapy, the average reduction of ALT was 2.3 Part IV. Elevated serum alanine transaminase level associated with stripping operation in thin film transistor workers: Is monoethanolamine the responsible agent? The purpose of this study was to determine the etiology of elevated levels of alanine aminotransferase (ALT) among workers in Taiwan’s thin film transistor (TFT) industry. 3875 out of 4051 workers completed a structured questionnaire. Everyone received blood tests for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus antibody (Anti-HCV), ALT, insulin, and ferritin, and also underwent ultrasonographic examination of liver. 1. Six hundred sixty-seven (17.2%) employees were found to have elevated levels of ALT. 2. The risk factors of ALT elevation were: HBsAg, anti-HCV, fatty liver, higher BMI, ferritin, insulin resistance, being male, being younger, and working in stripping department . 3. The major exposure occurred during stripping operation were a solvent containing 70% of monoethanolamine (MEA) and 30% of dimethyl sulfoxide (DMSO).