C-peptide concentration, mortality and vascular complications in people with Type 2 diabetes. The Skaraborg Diabetes Register

Aim To study the prognosis of patients with newly diagnosed Type 2 diabetes in primary care in relation to their baseline C-peptide concentration. Methods C-peptide concentrations were determined in 399 patients aged < 65 years with newly diagnosed Type 2 diabetes using the Skaraborg Diabetes Register, Sweden. Data on cardiovascular complications and death were extracted from national registers and a local study of retinopathy. Statistical analyses were performed using Cox regression. Results An analysis of C-peptide concentrations in quartiles, after adjusting for confounders, showed that patients in the highest quartile had a 2.75-fold higher risk of death from all causes compared with those in the lowest quartile (CI 1.17-6.47). By contrast, C-peptide concentration was not associated with the incidence of cardiovascular events or the development of retinopathy. Conclusions Measurement of C-peptide concentration at diagnosis could help identify patients who are at high risk and who presumably would benefit from more intensive treatment.