title: Type 1 and type 2 diabetes: what do they have in common?
abstract: Type 1 and type 2 diabetes frequently co-occur in the same families, suggesting common genetic susceptibility. Such mixed family history is associated with an intermediate phenotype of diabetes: insulin resistance and cardiovascular complications in type 1 diabetic patients and lower BMI and less cardiovascular complications as well as lower C-peptide concentrations in type 2 diabetic patients. GAD antibody positivity is more common in type 2 diabetic patients from mixed families than from common type 2 diabetes families. The mixed family history is associated with more type 1-like genetic (HLA and insulin gene) and phenotypic characteristics in type 2 diabetic patients, especially in the GAD antibody-positive subgroup. Leaving out the extreme ends of diabetes phenotypes, young children progressing rapidly to total insulin deficiency and strongly insulin-resistant subjects mostly with non-Europid ethnic origin, a large proportion of diabetic patients may have both type 1 and type 2 processes contributing to their diabetic phenotype.
authors.affiliation: Department of Internal Medicine/Diabetology, P.O. Box 340, Helsinki University Central Hospital, FIN-00029 HUS, Helsinki, Finland. tiinamaija.tuomi@hus.fi
authors.forename: Tiinamaija
authors.initials: T
authors.lastname: Tuomi
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D003922:Diabetes Mellitus, Type 1 / Q000145:classification* / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000145:classification* / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006680:HLA Antigens / Q000235:genetics*; D006681:HLA-D Antigens / Q000235:genetics; D006801:Humans; D008875:Middle Aged
chemical_list: D006680:HLA Antigens; D006681:HLA-D Antigens