Samples are collected at baseline and at 12 months for (1) other measures of iron status (serum hepcidin levels, soluble transferrin factor levels, percentage hypochromic red cells, reticulocyte haemoglobin content) [2]; other causes of anaemia (thyroid function tests, vitamin B12 and folate (only at baseline) [3]; inflammatory markers (serum tumour necrosis factor (TNF) alpha, interleukin-1 (IL-1) and interleukin-6 (IL-6); and [4] and marker of the metabolic syndrome (serum total adiponectin). This evidence concerns the gene IL6 and metabolic syndrome.