Associations between Lifestyle Factors and Iron Overload in Korean Adults

It has been suggested that iron overload, which indicates the accumulation of iron, generates cellular reactive oxygens and causes peroxide damages to the body. Such oxidative stresses, in a broader context, are also caused by lifestyles such as alcohol consumption and smoking. However, there are limited data on the association between these lifestyle factors and internal iron overload. In present study, we evaluated associations between lifestyle factors, such as smoking status, alcohol consumption, and physical activity, and serum markers of iron overload. In a population-based cross-sectional study including 2,347 Korean men and women aged 49-79 years, we assessed serum transferrin saturation (TSAT) levels and defined iron overload as TSAT levels > 50% for men and > 45% for women. After excluding persons with chronic diseases and iron deficiency, multivariate odds ratio (OR) and its 95% confidence interval (CI) were estimated to evaluate associations between lifestyle factors and iron overload in 1,973 participants. In all participants, we examined a significantly positive association between heavy alcohol consumption (> 30 g/day) and iron overload; heavy drinkers showed 1.6-fold higher OR (95% CI, 1.11-2.36) than non-drinkers. Stratified analysis by sex showed that this association was significant only among men. In addition, we observed a potential association between heavy smoking > 10 cigarettes/day and iron overload (p = 0.07). In stratified analysis by sex, we examined a significant association between smoking and iron overload only among women; former or current smokers had 1.9-fold higher OR (95% CI, 1.01-3.63) than never-smoker. Our findings suggest that heavy alcohol consumption and smoking may worsen iron accumulation in the body.