Dietary and serum vitamins and minerals as predictors of myocardial infarction and stroke in elderly subjects.
BACKGROUND AND AIM: According to a widespread hypothesis, antioxidative vitamins and trace elements may protect the body against atherosclerotic diseases, especially in the elderly. We assessed dietary and serum vitamins and minerals for prediction of acute myocardial infarction (AMI) and stroke in elderly subjects. METHODS AND RESULTS: In a population-based health survey with special emphasis on the diet, subjects aged 65-99 years were followed up for up to 10 years. The study population consisted of 361 men and 394 women. Information on individual food consumption was elicited by means of dietary history interviews. Serum vitamins and mineral elements were analysed utilizing commonly applied biochemical methods. Prediction analyses were based on 130 cases accumulated in the AMI group, 70 subjects in the stroke group, and corresponding control subjects. The cases were determined on the basis of revised information from the National Register of Cases of Death, and from the National Hospital Discharge Register. Low intake of vitamin D (p = 0.011) and low serum levels of 1,25-dihydroxy-vitamin D (p = 0.0053) were significantly predictive of stroke when adjusted for age, gender, smoking and functional capacity. On the other hand, high dietary intakes of two flavonoids, luteolin (p = 0.0096) and kaempferol (p = 0.002) were associated with lowered risk of AMI. Furthermore, low serum levels of iron predicted both AMI (p = 0.013) and stroke (p = 0.019). The results remained essentially unchanged when adjusted for additional major risk factors of atherosclerosis. CONCLUSIONS: From the items in the dietary interview, low intakes of vitamin D and certain flavonoids emerged as the sole predictors of AMI and stroke. In biochemical analyses, on the other hand, these disorders were predicted only by low levels of 1,25-dihydroxy-vitamin D and iron in the serum.