Mercury accumulation and accelerated progression of carotid atherosclerosis: a population-based prospective 4-year follow-up study in men in eastern Finland

Basic research and our previous studies have suggested that mercury exposur e enhances lipid peroxidation and the risk of myocardial infarction, but th ere are no studies concerning the association between mercury accumulation and atherosclerosis. We therefore investigated whether high hair mercury co ntent is associated with accelerated progression of carotid atherosclerosis , determined by ultrasonographic assessment of common carotid intima-media thickness (IMT), in a prospective study among 1014 men aged 42-60 years. In a linear regression model adjusting for other atherosclerotic risk factors , high hair mercury content was one of the strongest predictors of the 4-ye ar increase in the mean IMT (P = 0.0007). On the average, for each mu g/g i ncrease in hair mercury content, there was an increment of 8 mu m (7.3% of the mean) in the 4-year IMT increase. Men with hair mercury content of < 0. 49, 0.49-0.91, 0.92-1.49, 1.50-2.81 and > 2.81 mu g/g (fifths) had an IMT i ncrease of 0.105, 0.102, 0.113, 0.107 and 0.140 mm/4 years, respectively (P = 0.041 for heterogeneity between groups). The IMT increase was 0.034 mm/4 years (31.9%) greater in the highest fifth than in the other fifths (P < 0 .05 for the difference). These findings suggest that mercury accumulation i n the human body is associated with accelerated progression of carotid athe rosclerosis. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.