Crosstalk between the risk of diabetes and iron status in different ethnic groups

Abstract

Iron is an essential nutrient for biological metabolisms, such as hemoglobin synthesis, oxygen delivery, and enzyme activity. Both laboratory and clinical studies have evidenced that elevated iron status is associated with the abnormalities of glucose metabolism, insulin sensitivity, and ultimate diabetes. The risk of diabetes varies in different ethnic groups. The purpose of this study is to examine the impacts of diabetic factors on the serum iron content in various race groups. Relationships between serum iron content (quartile 1<64.7 ug/dL; 64.7 ug/dL <quartile 2< 86 ug/dL; 86 ug/dL <quartile 3<111 ug/dL; quartile 4>111 ug/dL) and BMI, waist, glucose, insulin, and diabetic status were examined using data from 2012–2013 National Health and Nutrition Examination Survey. Multinomial logistic regression was used to estimate the association between serum glucose and insulin level and quartile of serum iron, adjusted for age, gender, BMI, anemia, blood donation, alcohol drinking, smoking, and diabetes. Stratified analyses by different race groups were also performed. All statistical analyses were performed in SAS statistical software (SAS version 9.3). Results showed an inverse association between serum glucose and iron in the non‐Hispanic black group (p<0.05). In this race group, with one unit (mg/dL) increase in glucose, the chance of serum iron increase from quartile 1 (<64.7 ug/dL) to quartile 4 (>111 ug/dL) was about 29% (p<0.05). In the non‐Hispanic white group, increasing one unit (uU/mL) of insulin resulted in a possibility of 2% increase of the serum iron level (p<0.05). BMI was associated with decreased iron content in non‐Hispanic black, but not other race groups. The increase in age was associated with higher iron content in non‐Hispanic black and white groups (p<0.05). The female had a lower iron content compared to male in all ethnic groups studied (p<0.05). The impacts of other factors, such as blood donation, smoking, and alcohol drinking, on serum iron quartiles varied in race groups. Overall, the data suggest the existence of bridges between diabetic related factors and serum iron content. Furthermore, the crosstalk between iron status and diabetes is ethnic group dependent.