Iron Depletion in Rats May Protect Against Atherosclerosis and Ischemic Heart Disease

Experimental evidence cites that iron overload enhances and iron depletion decreases the formation of an atherosclerotic plaque. Many facts seem to support this hypothesis. It helps to explain the striking sex difference in heart disease. In premenopausal women, incidence of atherosclerosis and coronary vascular disease (CVD) is less than half that of age-matched men. Depletion of iron stores by regular menstrual blood loss may be a source of protection in premenopausal patients. Menstruating women maintain the negligible levels of stored iron found in both men and women prior to age 20. Men lacking the menstrual iron ‘leak’ undergo progressive accumulation of iron rising rapidly with age. At age 45, men have roughly 4 times more iron in storage than women. To test this hypothesis, an animal rat protocol was followed. Two groups (N = 10 for each) of mature adult Sprague-Dawley rats were selected. Basal serum ferritin levels were recorded and the two groups were given one of two diets, a normal chow or a high-iron diet for a period of 4 weeks. Serum ferritin levels were measured at 2 and 4 weeks. Five rats from each group were killed after 2 weeks and the remaining 5 animals after 4 weeks. Blood was collected for a lipid profile and a complete blood count and coronary vessels were examined for atherosclerotic changes. Three serial sections of the coronaries starting from the origin of the arteries were taken and examined histopathologically. In a retrospective study in both human sexes, which was taken from the records of the clinical laboratories in the Eastern Province of Saudi Arabia, there was a significant correlation between coronary artery disease (myocardial infarction) and the higher serum ferritin levels.