Increased body mass index and waist circumference exert opposite effects on body iron status: A systematic review

Abstract

Obesity is a health-related condition at the forefront of chronic metabolic disorders. It presents with raised body mass index (BMI) and large waist circumference (WC). Raised BMI is negatively associated with blood iron levels while large waist circumference is positively associated with blood iron levels. Factors and mechanisms determining such conflicting relationships are hardly clarified. The aim of the present review was to clarify this association dilemma between the two obesity manifestations with blood iron levels. Original articles were targeted and literature review was from 1963 to 2015. Various words combinations were used to search for relevant articles. Science Direct, Google Scholar, PubMed, NIH Public Access, Medline and Medscape were the databases used to search for the articles. A total of 100 articles were retrieved and 61 of them were found suitable for literature review for the topic in question. The identified articles were examined for further relevant references. All articles that referred to the association or relationship of BMI and WC with iron were assessed. The present study identified lack of homogeneity in adipose tissues, uneven distribution of leptin, interleukin 6 and tissue necrosis factor α, genetic variability of adipocytokines and hepcidin mRNA, different mRNAs across adipose tissues throughout the body, as determinants of hepcidin function in adipose tissues. In conclusion, conflicting effects of increased BMI and large WC with blood iron status are thought to be attributable to variation in adipose tissues, distribution of adipocytokines and markers, interaction of adipocytokines with the anti-inflammatory markers, the nature and activity of hepcidin.

Keywords: Obesity, body mass index, waist circumference, adipocytokines, iron, hepcidin