Myocardial infarction risk in relation to zinc concentration in toenails

Abstract

Zn is an essential mineral. The role of Zn in atherosclerosis is not clear. Epidemiological studies, which have reported contradictory results, are limited by the use of serum Zn levels as a marker of intake. We assessed the association of toenail Zn, which integrates dietary Zn intake over 3 to 12 months, with the risk of a first myocardial infarction. Toenail Zn concentrations were determined by neutron activation analysis in the European multi-centre case -control study on antioxidants, myocardial infarction and breast cancer. This multi-centre case -control study included 684 cases and 724 controls from eight European countries and Israel. Toenail Zn levels of controls (adjusted for age and study centre) were positively associated with age, a-tocopherol and Se, but not with additional dietary variables or with classical risk factors for CHD. Average toenail Zn was 106·0 mg/kg in cases (95 % CI 103·1, 108·9) and 107·5 mg/kg in controls (95 % CI 104·5, 110·7). After controlling for cardiovascular risk factors and for centre, the adjusted odds ratios of myocardial infarction for quintiles 2 -5 of toenail Zn with respect to the first quintile were 0·97 (95 % CI 0·59, 1·58), 1·15 (95 % CI 0·72, 1·85), 0·91 (95 % CI 0·56, 1·50), and 0·85 (95 % CI 0·52, 1·39). The P for trend was 0·45. In conclusion toenail Zn levels (reflecting long-term dietary intake) were not significantly associated with acute myocardial infarction.

Deficient Zinc Levels and Myocardial Infarction

“…First, there were 10 case-control studies to measure the toenail Zn level which was inconsistent with the serum and hair Zn level, and all these case-control studies were from the study performed by Martin-Moreno in 2003. Thus, the inconsistency of the results of subgroup analyses stratified by sample specimen was caused by the study of Martin-Moreno (2003).…”

“…And the difference of Zn levels between MI and healthy controls in Asia was greater to that among the population in Europe, but no difference was found in Oceania. And we found that the inconsistency of the results of subgroup analyses might be caused by a study of Martin-Moreno (2003). First, there were 10 case-control studies to measure the toenail Zn level which was inconsistent with the serum and hair Zn level, and all these case-control studies were from the study performed by Martin-Moreno in 2003.…”

“…Some clinical studies found that there was a significant relationship between Zn deficiency and MI risk [11][12][13][14]. However, some studies suggest that there is no correlation between Zn levels and MI risk [15][16][17]. Although Zn deficiency is plausibly linked to an increase risk of MI, the inconsistency among the findings of previous studies precludes definitive recommendations at present.…”

“…(n=19), (3) non-human studies (n=69), and (4) articles not providing Zn levels for both subjects with MI and healthy controls (n=3). Overall, thirteen eligible articles with 2886 subjects from 41 case-control studies were considered in the analysis [11][12][13][14][15][16][17][18][19][20][21][22][23]. A flow diagram of the study selection process is presented in Fig 1. …”

Investigation of the Content and of the Distribution of Chemical Elements in Human Nails by SRXRF

“…The prostate gland hazard does not grow when the content of cadmium in toe-nails increases and does not decay when the zinc content increases. Martin-Moreno et al (2003) investigated the correlation between the zinc content in toenails and the hazard of cardiac infarct in European population. The authors have shown that the zinc content in nails of sick people differs slightly (slightly is not an analytical expression) from that in nails of healthy people.…”