MAGNESIUM IN DRINKING-WATER AND DEATH FROM ACUTE MYOCARDIAL-INFARCTION

The relation between death from acute myocardial infarction and the le vel of magnesium in drinking water was examined using mortality regist ers and a case-control design. The study area comprised 17 municipalit ies in the southern part of Sweden that have different magnesium level s in the drinking water. Cases were men in the area who had died of ac ute myocardial infarction between ages 50 and 69 years during the peri od 1982-1989 (n = 854). The controls were men of the same age in the s ame area who had died from cancer during the same time period (n = 989 ). In both groups, only men who consumed water supplied from municipal waterworks were included in the study. The subjects were divided into quartiles according to the drinking water levels of magnesium and cal cium and the quotient between magnesium and calcium. The odds ratios f or death from acute myocardial infarction in the groups were inversely related to the amount of magnesium in drinking water. For the group w ith the highest levels of magnesium in drinking water, the odds ratio adjusted for age and calcium level was 0.65 (95 percent confidence int erval 0.50-0.84). There was no such relation for calcium. For the magn esium/calcium quotient, the odds ratio was lower only for the group wi th the highest quotient, These data suggest that magnesium in drinking water is an important protective factor for death from acute myocardi al infarction among males.