Serum Iron and Body Fat Distribution in a Multiethnic Cohort of Adults Living in New York City

Abstract

Objective To examine the relationship between serum iron and body composition in a multiracial adult cohort. Methods The analysis consisted of 670 participants on whom blood analysis and anthropometric data were available. The participants were recruited as part of the Rosetta Study (1990-2000), which was designed to assess body composition in a multiethnic cohort of healthy adults. Fasting iron level was measured as part of a biochemistry panel. Dual x-ray absorptiometry was used to assess fat mass. Anthropometric measures included waist circumference and body mass index (BMI; calculated as kg/m 2) as an index of abdominal adiposity and overall body fatness, respectively. Results In the study cohort the mean age was 54±17 years and 60.9% were overweight or obese (BMI ≥25). Men had higher serum iron levels (94.91±34.52 μg/dL [16.99±6.18 μmol/L] vs 82.17±32.62 μg/dL [14.71±5.84 μmol/L]) and larger waist circumference (91.98±11.87 cm vs 85.24±12.37 cm) compared with women ( P<0.001). Iron was inversely correlated with BMI ( r=−0.23, P<0.001), waist circumference ( r=−0.19, P<0.05), and fat mass ( r=−0.19, P<0.05) among Hispanic women but not among African-American, white, or Asian women or in men of any race/ethnic group. Conclusions The results of this study show an inverse association of measures of body fat distribution and total fat mass with serum iron level in Hispanic women. Studies designed to explore how micronutrients are used by the body at varying degrees of body fatness could provide useful information on the micronutrient-related comorbidities of obesity.