Iron stores and cardiovascular disease risk factors in women of reproductive age in the United States

Abstract

The increasing proportion of iron-replete individuals in industrialized countries and the possible increased risk of cardiovascular disease (CVD) among men with high iron stores raise concerns regarding improved iron status in women of reproductive age. This study examined the association between iron stores and a set of established CVD risk factors among nonpregnant women aged 20-49 y. Data from the third National Health and Nutrition Examination Survey (1988-1994) were used to examine the relation between race-ethnicity-specific quartiles of serum ferritin (SF) and a set of CVD risk factors [body mass index (BMI), total cholesterol, triacylglycerol, HDL cholesterol, plasma glucose, and blood pressure (BP)]. Women with a history of CVD or liver disease were excluded. We controlled for age, session of measurement, prevalent infection, recent blood donation, and treatment with iron for anemia. Mean SF values were 53.22 +/- 2.08 micro g/L (n = 1178), 58.93 +/- 2.39 micro g/L (n = 1093), and 43.33 +/- 1.39 micro g/L (n = 1075) among non-Hispanic white, non-Hispanic black, and Mexican American women, respectively. Iron stores were positively associated with CVD risk factors only among non-Hispanic black and Mexican American women after adjustment for confounding variables. The strongest associations were seen among Mexican American women: compared with the middle 2 quartiles, the lowest and highest quartiles of SF had lower and higher values, respectively, for BMI, total cholesterol, triacylglycerol, glucose, and diastolic BP. These findings suggest that CVD risk factors, especially those related to glucose and lipid metabolism, are positively associated with iron status in women.