[Type 2 diabetes: journey in the heart of a complex disease]

The prevalence of type 2 diabetes is rapidly growing worldwide and this metabolic disease nowadays represents a major public health concern. Besides the effects of aging, such a progression results from the interaction of several phenomena among which (1) a rather common genetic (polygenic) predisposing pattern, (2) epigenetic mechanisms, at least partially linked to nutritional disturbances during gestation influencing fetal programming, and especially, (3) a deleterious societal environment promoting the development of obesity by giving free access to excess food (rich in calories, sucrose and lipids) and markedly limiting spontaneous physical activity, or exposing to pollutants that could exert a toxic effect on the B cell. Such an obesogenic environment, already present in young age, leads to an epidemics of "diabesity". A better knowledge of the natural history of type 2 diabetes opens perspectives for the prevention of this complex disease. When type 2 diabetes is already present, a global therapeutic approach targeting environment by the promotion of lifestyle changes and the correction of all risk factors is mandatory to reduce the incidence of complications, essentially cardiovascular diseases.