Iron deficiency and risk factors in pre-menopausal females living in Auckland, New Zealand.

Abstract

Iron deficiency is prevalent in New Zealand, with low dietary haem intake and blood loss previously identified as risk factors. However, the influence of the hormone hepcidin on iron status has not been investigated. Females (n=170) aged 18-45 residing in Auckland participated in a cross-sectional study. Iron status and inflammation were assessed with serum biomarkers including; serum ferritin, haemoglobin, soluble transferrin receptor, hepcidin, C-reactive protein and interleukin-6. Lifestyle factors were assessed using a series of validated questionnaires, including an iron food frequency questionnaire. Potential determinants of serum ferritin were identified using multiple linear regression analysis. Iron insufficiency was confirmed in 55.8% of participants (Serum ferritin <30 μg·L-1). Hepcidin levels were higher in those who were iron sufficient (Serum ferritin ≥30 μg·L-1) (6.62 nM vs 1.17 nM, p<0.001). South Asian females had higher hepcidin (8.78 nM) levels, compared to New Zealand Europeans (6.28 nM) (p=0.018), a result likely due to South Asians presenting with higher interleukin-6 (1.66 vs 0.63 pg·mL-1, p<0.001). Hepcidin (β=0.082, p<0.001) and frequency of meat intake (β=0.058, p=0.001) were identified as significant predictors of serum ferritin in New Zealand Europeans, while hepcidin was the only identified predictor in South Asians (β=0.138, p<0.001) and those of other ethnicities (β=0.117, p<0.002). This is the first study in New Zealand to show that hepcidin levels strongly predict serum ferritin in premenopausal females. Additionally, frequency of meat intake appears to be an important determinant of iron status in New Zealand Europeans.