Heme iron intake and acute myocardial infarction: a prospective study of men.
BACKGROUND
Epidemiologic studies of heme iron and non-heme iron intake in relation to risk of acute myocardial infarction (AMI) are lacking. Therefore, we examine the associations between heme iron and non-heme iron intake and fatal and nonfatal AMI in men. Moreover, we investigated whether the associations were modified by intake of minerals (calcium, magnesium, and zinc) that decreases iron absorption.


METHODS
The population-based prospective cohort of Swedish Men (COSM) included 36882 men, aged 45-79 years, who completed a self-administered questionnaire on diet and had no history of coronary heart disease, stroke, diabetes, or cancer at baseline.


RESULTS
During an 11.7 year follow-up, 678 fatal and 2593 nonfatal AMI events were registered. The hazard ratio (HR) of fatal AMI among men in the highest compared with the lowest quintile of heme iron intake was 1.51 (95%CI: 1.07-2.13, P-trend=0.02). The association was confined to men with a low intake of minerals that can decrease iron absorption. Among men with combined intakes of calcium, magnesium, and zinc below the medians, the HR of fatal AMI was 2.89 (95%CI: 1.43-5.82) for the highest vs. the lowest quintile of heme iron intake. There was no association between heme iron intake and nonfatal AMI, or between non-heme iron intake and fatal or nonfatal AMI.


CONCLUSIONS
Findings from this prospective study indicate that a high heme iron intake, particularly with simultaneous low intake of minerals that can decrease iron absorption, may increase the risk of fatal AMI.
Department of Human Nutrition, Warsaw University of Life Sciences-SGGW Warsaw, Poland. Electronic address: joanna_kaluza@sggw.pl.
Joanna
J
Kaluza
Division of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Susanna C
SC
Larsson
Division of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Niclas
N
Håkansson
Division of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Alicja
A
Wolk
D000368:Aged; D002118:Calcium / Q000008:administration & dosage; D005247:Feeding Behavior; D005500:Follow-Up Studies; D006418:Heme / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D007501:Iron / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D008274:Magnesium / Q000008:administration & dosage; D008297:Male; D008460:Meat; D008875:Middle Aged; D009203:Myocardial Infarction / Q000378:metabolism* / Q000401:mortality*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D015032:Zinc / Q000008:administration & dosage
D006418:Heme; D007501:Iron; D008274:Magnesium; D015032:Zinc; D002118:Calcium
Acute myocardial infarction; Heme iron; Non-heme iron; Prospective cohort study