C-peptide, BMI and age in newly diagnosed diabetes

Classification of diabetes at presentation is often difficult in adults, adolescents and the elderly. This is because of the high incidence of autoimmune diabetes. In addition to a clinical classification based on age, body mass index (BMI), ketoacidosis and other symptoms, there is also a need for better tools for classification, as the type of diabetes has implications for choice of treatment and long-term prognosis, including development of complications.

The importance of the level of blood-cell function, measured as C-peptide, is well recognised in autoimmune diabetes both through its correlation with endogenous insulin secretion and in relation to complications. In non-autoimmune diabetes also, interest in blood-cell function has recently increased considerably. Preservation of blood-cell function after diagnosis of diabetes is now a goal in clinical trials of non-autoimmune diabetes.

Thunander et al. aimed to study and describe the levels of C-peptide and BMI, and their relation to age and antibody status, in a large population-based study of adults with newly diagnosed diabetes and to explore the usefulness of C-peptide levels, BMI and age in classification of diabetes type at diagnosis of diabetes in adults.

They found that at diagnosis of diabetes, C-peptide was superior to age and BMI in discriminating between autoimmune and non-autoimmune diabetes. C-peptide increased significantly with BMI and age, the latter also within each BMI group. Most of the adults had normal or high levels of C-peptide at presentation of diabetes among the autoimmune patients. Thunander et al. (2012) European Journal of Endocrinology 166 1021-1029.

Read the full article at DOI: 10.1530/EJE-11-0797