Obesity and iron deficiency: a quantitative meta‐analysis

Abstract

Hypoferraemia (i.e. iron deficiency) was initially reported among obese individuals several decades ago; however, whether obesity and iron deficiency are correlated remains unclear. Here, we evaluated the putative association between obesity and iron deficiency by assessing the concentration of haematological iron markers and the risks associated with iron deficiency in both obese (including overweight) subjects and non-overweight participants. We performed a systematic search in the databases PubMed and Embase for relevant research articles published through December 2014. A total of 26 cross-sectional and case-control studies were analysed, comprising 13,393 overweight/obese individuals and 26,621 non-overweight participants. Weighted or standardized mean differences of blood iron markers and odds ratio (OR) of iron deficiency were compared between the overweight/obese participants and the non-overweight participants using a random-effects model. Compared with the non-overweight participants, the overweight/obese participants had lower serum iron concentrations (weighted mean difference [WMD]: -8.37 μg dL(-1) ; 95% confidence interval [CI]: -11.38 to -5.36 μg dL(-1) ) and lower transferrin saturation percentages (WMD: 2.34%, 95% CI: -3.29% to -1.40%). Consistent with this finding, the overweight/obese participants had a significantly increased risk of iron deficiency (OR: 1.31; 95% CI: 1.01-1.68). Moreover, subgroup analyses revealed that the method used to diagnose iron deficiency can have a critical effect on the results of the association test; specifically, we found a significant correlation between iron deficiency and obesity in studies without a ferritin-based diagnosis, but not in studies that used a ferritin-based diagnosis. Based upon these findings, we concluded that obesity is significantly associated with iron deficiency, and we recommend early monitoring and treatment of iron deficiency in overweight and obese individuals. Future longitudinal studies will help to test whether causal relationship exists between obesity and iron deficiency.

Iron deficiency anemia and megaloblastic anemia in obese patients

“…In a study by Zhao et al [11], obese patients had lower levels of hemoglobin as well as lower serum ferritin when compared to non-obese ones. In a study by Manios et al [12], both obese men and women had lower serum hemoglobin and serum ferritin than nonobese patients.…”

Relação entre consumo alimentar de vitaminas e minerais, índice de massa corporal e circunferência da cintura: um estudo de base populacional com adultos no Sul do Brasil

“…Um exemplo disso é o que ocorre com o ferro. Segundo uma metanálise publicada em 2015, além de o baixo consumo do micronutriente favorecer a obesidade, no indivíduo obeso, a própria inflamação que acompanha a obesidade pode diminuir a sua absorção e contribuir para a manutenção e/ou exacerbação desse agravo 37 .…”

“…A gravidade desses resultados concentra-se sobretudo no fato de que, além de favorecer a obesidade, o consumo inadequado de ferro ainda contribui para a ocorrência da anemia, doença com importantes repercussões negativas à saúde. 11,37 .…”

Iron Deficiency Anemia and Pregnancy

“…Timed recognition and proper treatment of ID could significantly alter health indicators, not only on an individual level but also on a population level. The more recent findings shed a new light on ID which favors the proposed idea; obesity has been linked to low iron stores, confirmed in both pregnant women and children [20,[33][34][35][36][37].…”