icon-folder.gif   Conference Reports for NATAP  
  The Digestive Disease Week 2003 Conference
Orlando, Florida May 17-23, 2003
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  DDW Conference. May 17-22, 2003, Orlando, Florida. Constance E Ruhl, James E Everhart, Silver Spring, MD; Bethesda, MD. Background & Aims: Oxidative stress is thought to play a role in the liver injury due to nonalcoholic steatohepatitis (NASH). Hepatic iron may promote liver injury, whereas certain vitamins and minerals (antioxidants) may inhibit it, but few clinical studies have examined such relationships. We analysed the associations of serum iron measures and antioxidant concentrations with abnormal serum alanine aminotransferase (ALT) activity in a national, population-based study. Methods: Serum transferrin saturation and serum iron, vitamins C and E, selenium, and five carotenoid concentrations were measured in 13,605 adult participants in the third U.S. National Health and Nutrition Examination Survey, 1988-1994. Exclusions included excessive alcohol consumption, hepatitis B or C, and iron overload. Liver injury was indicated by elevated serum ALT activity (> 43 U/L). Serum nutrient concentrations were expressed as deciles (10th percentiles). All analyses incorporated sample weights and the design effects of the survey. Results: Elevated ALT activity was found in 3.1% of the population. In univariate analysis, factors associated with abnormal ALT activity (p<0.05) included higher serum transferrin saturation and iron and selenium concentrations, and lower serum vitamin C, alpha carotene, beta carotene, and lutein/zeaxanthin concentrations. In multivariate logistic regression analyses, elevated ALT was positively associated with increasing deciles of transferrin saturation and iron concentration and negatively associated with increasing deciles of alpha carotene, beta carotene, beta cryptoxanthin, and lutein/zeaxanthin concentrations (table). A variable combining the five carotenoid measures was also negatively associated with abnormal ALT (odds ratio per decile increase = 0.89, 95% CI=0.83-0.95). Vitamin C was inversely associated, but only at the highest serum concentrations. Conclusion: In this large, national, population-based study, the risk of liver injury most likely due to NASH was associated with increased serum iron and decreased serum antioxidants, particularly carotenoids.