[New viewpoints on the pathogenesis of diabetes mellitus]

Diabetes mellitus is a syndrome characterised primarily by an increase in blood glucose and an absolute or relative deficiency of insulin. Etiologically, it is a complex disorder because many different genetic, environmental, immunological, metabolic and hormonal influences interact to produce the clinical picture diabetes. By introducing HLA typing in diabetes research in the last four years, it became possible to clearly distinguish between the juvenile-onset, insulin-dependent type and the non-insulin-dependent, maturity-onset type of diabetes mellitus. On the basis of this and other evidence, at least five nosologically distinct types of diabetes can be identified.