Association between toenail scandium levels and risk of acute myocardial infarction in European men: the EURAMIC and Heavy Metals Study

The association between scandium status and risk of acute myocardial infarction (MI) was examined in a multicentre case control study in 10 centres from Europe and Israel. Scandium in toenails was assessed in 684 cases and 724 controls less than 70 years of age. Mean concentrations of toenail scandium were 6.74 micro/kg in cases and 7.75 microg/kg in controls. Scandium among controls, adjusted for age and centre was positively associated with concentrations of lycopene and oleic acid in adipose tissue (P = 0.002 for both nutrients). Pearson correlations adjusted for age and centre were significant (P < 0.05) between scandium and lycopene (r = 0.08), zinc (r = 0.08), mercury (r = 0.18) and oleic acid (r = 0.21). Overall, cases had lower levels of scandium than controls after adjustment for age and centre (case control ratio, 0.87; 95% CI 0.79-0.96). This association persisted after adjustment for other cardiovascular risk factors (case-control ratio 0.88; 95% CI, 0.79-0.98). The risk of MI at high scandium levels was reduced after adjustment for age and centre (P-trend = 0.04). Further adjustments for BMI, history of hypertension, smoking, alcohol intake, diabetes, family history of CHD, alpha-tocopherol, beta-carotene, lycopene, selenium and mercury slightly attenuated this trend (P = 0.055). Our results suggest that toenail scandium level is associated with a reduced risk of acute MI, but we are uncertain whether this element can really play a protective role in the development of CHD. Without an identified plausible mechanism, these results should be regarded as preliminary and should be tested in future studies.