A prospective nested case–control study within the PREvention with MEDiterranean Diet (PREDIMED) was conducted to evaluate the relationship between excess body Fe (measured as serum ferritin (SF), soluble transferrin receptor (sTfR) and sTfR:ferritin ratio) and the risk of type 2 diabetes mellitus (T2DM) in a Mediterranean population at a high risk of CVD, without T2DM at the start of the study. The study contained 459 subjects, 153 with incident T2DM (cases) and 306 without incident T2DM (controls). The follow-up period was for 6·0 (interquartile range 3·9–6·5) years. For each incident diabetic subject, two subjects were selected as controls who were matched broadly for age as well as for sex, intervention group and BMI. We observed a relationship between SF values >257 μg/l in males and >139 μg/l in females and the risk of T2DM, following adjustment in the conditional logistic regression model for high-sensitivity C-reactive protein, fasting glucose and other components of the metabolic syndrome (OR 3·62, 95 % CI 1·32, 19·95; P= 0·022). We also found an association between low sTfR:ferritin ratio levels and the incidence of T2DM (OR 3·02, 95 % CI 1·09, 8·39; P= 0·042), but no association with sTfR (OR 1·29, 95 % CI 0·51, 3·23; P= 0·722). Oxidative stress has been hypothesised to contribute to the development of insulin resistance and β-cell dysfunction, the two key events in the clinical development of T2DM. Following adjustment for other risk factors for T2DM, excess body Fe (measured as SF and sTfR:ferritin ratio) was associated with an increased risk of developing T2DM in a Mediterranean population at a high risk of CVD.

Anaemia is prevalent in South East Asia and Fe deficiency (ID) is considered to be the main cause, but the role of subclinical inflammation in the aetiology is uncertain. In the present study, we determined the influence of inflammation on the biomarkers of Fe status in women and children, and herein, we discuss the proportion of anaemia associated with ID. As part of the 2006 Lao People's Democratic Republic (The Lao PDR) National Nutrition Survey, blood collected from 482 young children and 816 non-pregnant women was analysed. Plasma ferritin, transferrin receptor (sTfR), Hb, C-reactive protein (CRP) and α-1-acid glycoprotein (AGP) concentrations were measured. ID was assessed using ferritin concentrations ( < 12 (children) or < 15 (adults) μg/l), sTfR concentrations (>8·3 mg/l) and body Fe stores (BIS < 0). Elevated CRP (>5 mg/l) and/or AGP (>1 g/l) concentrations were used to categorise inflammation status in order to correct the Fe biomarkers for inflammation. Inflammation was present in 14 % of adults and 43 % of children. Anaemia was present in 37·6 % of both women (Hb concentrations < 120 g/l) and children (Hb concentrations < 110 g/l). Correcting ferritin concentrations for inflammation increased the prevalence of ID from 24·3 to 26 % for women and from 18 to 21 % for children (P< 0·001 for both). Ferritin concentrations were more helpful in detecting ID than sTfR concentrations or BIS, but regression analysis found that sTfr concentrations explained more of the variance in Hb concentrations in both women (20 %) and children (17 %) than ferritin concentrations (5 and 1·4 %, respectively). Nevertheless, the total variance in Hb concentrations explained was only 26 and 18 % in women and children, respectively, and other factors may be more important than ID in contributing to anaemia in The Lao PDR.

Estimates of iron status in a random sample (218 men, 283 women) of the Northern Ireland population (aged 18–64 years) were obtained from blood measurements. Multiple criteria were used to determine Fe deficiency and body Fe stores were calculated as an index of Fe sufficiency. Three distinct groups with respect to Fe stores were identified on the basis of sex and menstrual status. Estimates of body Fe stores, mean (and SD), were 13.4 (SD 5.97), 5.3 (SD 6.09) and 8.5 (SD 6.72) mM for men, women aged 18–44 years and women aged 45–64 years respectively. The prevalence of Fe-deficincy was low. ranging from 0.5% in men to 6.6% and 4.6% in the younger and older women respectively. The prevalence of Fe deficiency was low in men (1.4%) and older women (5.7%) rising to 11.0% in the younger group of women. The disproportionately elevated serum ferritin relative to transferrimn saturation supported the suggestion that chronic inflammation might have influenced Fe status measurements in men and older women.