The value of basal C peptide and its relationship with pancreatic autoantibodies in young adults with type 2 diabetes mellitus.

UNLABELLED

It is well known that sometimes it is difficult to distinguish between type 1 and 2 diabetes mellitus using clinical criteria, in subjects with disease onset relatively early in adult life. The measurement of C peptide level and of immunological markers may represent important additional tools for establishing the correct diagnosis. The aim of the study is to assess the trend of basal C peptide in patients with clinical diagnosis of type 2 diabetes and to relate it to the type of treatment, the body weight and the positivity for pancreatic autoantibodies.

PATIENTS AND METHOD

we studied a group of 268 patients with type 2 diabetes, aged between 30 and 50 years, with a diabetes duration of less than 5 years. In all patients, we measured basal C peptide, islet cell autoantibodies and antibodies against glutamic acid decarboxylase, computed the body mass index and recorded the current antidiabetic treatment.

RESULTS

Based on basal C peptide value, diabetic subjects fell under 3 categories: a) low C peptide (<0.58 ng/ml): 7.5%, b) normal C peptide (0.58-2.70 ng/ml): 57.8%, and c) high C peptide (>2.70 ng/ml): 34.7%. Patients with low C peptide were treated more often with insulin, while those in high C peptide group received more often biguanides. A direct correlation between C peptide and body weight was established. Mean C peptide was lower in patients positive for at least one pancreatic autoantibody, compared to those who were negative for antibodies

CONCLUSION

Low basal C peptide can be considered criterion for transferring the patients, initially diagnosed as type 2 diabetes, in the type 1 diabetes group.