[Diabetes mellitus: from clinical knowledge to public health concern].

Diabetes mellitus is a chronic disease whose prevalence is increasing worldwide. It remains associated with a high risk of severe complications, essentially micro- and macro-vascular complications. Type 1 diabetes is an auto-immune disease that leads to the destruction of insulin-secreting B cells and therefore requires an intensive optimised exogenous insulin therapy. Type 2 diabetes is a polygenic disease whose expression is favoured by inadequate lifestyle, leading to obesity. It combines a relative insulin secretory defect and insulin resistance, the latter being associated with various other cardiovascular risk factors. Treatment consists of lifestyle modifications first, then the prescription of various glucose-lowering oral drugs and finally, when requested, insulin therapy. A multi-risk intervention is mandatory to improve the cardiovascular prognosis. The prevention of diabetes and its complications is a major public health objective.