The double burden of obesity and iron deficiency on children and adolescents in Greece: the Healthy Growth Study

Abstract

Some small cohort studies have noted that obesity co-exists with lower serum iron levels. The present study aimed to examine the association between being overweight and iron deficiency (ID) in a large cohort of Greek children and adolescents. A representative sample of 2492 primary schoolchildren aged 9-13 years old was examined. Anthropometric, biochemical, clinical, dietary intake and physical activity data were collected. The prevalence of ID and iron deficiency anaemia (IDA) was higher in obese boys and girls compared to their normal-weight peers (P < 0.05). Serum ferritin was higher in obese compared to normal-weight boys (P = 0.024) and higher in obese compared to normal-weight and overweight girls (P = 0.001). By contrast, a negative association was found between transferrin saturation and adiposity in both boys and girls (P = 0.001 and P = 0.005). Furthermore, obese girls had significantly higher fibre intake than normal-weight girls (P = 0.048) and also overweight and obese boys and girls recorded significantly fewer pedometer steps than their normal-weight peers (P < 0.001). Finally, obesity more than doubled the likelihood of ID in both boys (odds ratio = 2.83; 95% confidence inteval = 1.65-4.85) and girls (odds ratio = 2.03; 95% confidence interval = 1.08-3.81) after controlling for certain lifestyle and clinical indices as potential confounders. The present study shows that obese children and adolescents were at greater risk for ID and IDA than their normal-weight peers. Low grade inflammation induced by excessive adiposity may be a reason for the observed low iron levels. This is also strengthened by the elevated serum ferritin levels, comprising an acute phase protein that is plausibly increased in inflammation.