Objective: To determine the relative importance of HFE gene, diet, lifestyle, and blood loss characteristics for predicting iron status in a sample of men aged 40 years or over.
Design: Iron status (serum ferritin, transferrin saturation, soluble transferrin receptor) was measured in 44 C282Y heterozygote and 85 age- and BMI-matched wildtype men aged 40 years or over. Dietary intake of iron (total, heme and non-heme), and components known to influence iron bioavailability, was determined using a validated Meal-Based Intake Assessment Tool. Information on lifestyle and blood loss was obtained by questionnaire. Height and weight were measured to determine Quetelet's body mass index. Linear mixed models were used to determine the extent to which these variables predicted iron status.
Results: C282Y heterozygosity was associated with 17% higher transferrin saturation (95% CI: 6%, 29%) but no difference in serum ferritin or soluble transferrin receptor concentrations. Blood donation was negatively associated with transferrin saturation (-13% (- 3%, -22%)) and serum ferritin (-58% (-44%, -68%)), and had a marginally significant positive association with soluble transferrin receptor concentration. Self-reported fecal blood loss was negatively associated with serum ferritin concentration (-35% (-54%, -7%)). Alcohol was the only dietary variable associated with iron status and was associated with all three of the iron status indices. Serum ferritin concentration was positively associated with body mass index (10% per unit increase (6%, 15%)).
Conclusions: Blood loss was a stronger predictor of iron status than either C282Y heterozygosity or diet in this population of men aged 40 years and over.