Type 1 diabetes and environment

Type 1 diabetes is a chronic autoimmune disease directed towards the pancre atic beta-cells and resulting in absolute insulin deficiency. Its long prec linical specific stage markers of ongoing autoimmune disease. Type 1 diabet es occurs in genetically predisposed individuals. However, in monozygotic t wins, the concordance rate for the disease is only partial. This, and the r apid increase in the incidence of type 1 diabetes over the recent years sug gest that environmental factors modulate the onset or the progression of th e autoimmune process. Many putative agents, particularly viruses and diet f actors, have been suspected, mainly on the basis of epidemiological studies . Among viruses, enteroviruses, particularly coxsackie, may either initiate the disease by materno-foetal infection or enhance autoimmune disease thro ugh bystander activation. A short duration of breast-feeding and the early introduction of cow's milk have been also epidemiologically involved in the onset of type 1 diabetes, but the mechanisms of this association remain el usive, The identification of environmental promoters of type 1 diabetes is a difficult task because various agents may be implicated, and some may be also protective as shown in experimental models. Prospective studies in at- risk individuals are needed to identify common environmental triggers of ty pe 1 diabetes before primary prevention may be envisaged.