Our observation that a combination of hyperglycemia and high-fat feeding leads to elevated CD11b+CD68+ cells is consistent with a diabetes-driven phenotype of increased circulating monocytes and tissue microglia, and suggests that inflammatory signalling is also likely to be implicated in both the systemic and central complications of diabetes, analogous to the known contribution of inflammation to other neurological disorders [28]. This evidence concerns the gene ITGAM and diabetes mellitus.