C-peptide and chronic complications in patients with type-2 diabetes and the metabolic syndrome

Introduction > We investigated the relation between C-peptide levels and the prevalence of diabetic complications in patients with type 2 diabetes and the metabolic syndrome. Methods > This study includes all patients with diabetes and treated only with oral hypoglycemic agents who were admitted to our department in 2006. The chronic complications of diabetes (vascular disease, retinopathy, nephropathy, neuropathy) were evaluated. Results > The 77 patients with type 2 diabetes and treated only with oral hypoglycemic agents were divided in two groups, with and without the metabolic syndrome. The two groups did not differ in glycemic control, blood pressure levels, or duration of diabetes. CRP levels were higher in patients with the metabolic syndrome (p = 0.03), and nephropathy was more common (70%, compared with 33%). Similar, C-peptide levels were higher in patients with the metabolic syndrome: 3.12 +/- 1.36 compared with 1.82 +/- 1.25 (p < 0.001). In patients with the metabolic syndrome, C-peptide levels did not differ in patients with or without diabetic complications (3.01 +/- 1.16, compared with 3.96 +/- 2.55; p = 0.51). Similarly, C-peptide levels in patients without the metabolic syndrome did not differ according to the presence of complications of diabetes (2.25 +/- 1.21 versus 1.36 +/- 1.16; p = 0.07). However, C-peptide levels were higher in patients with diabetes and the metabolic syndrome who had either nephropathy or vascular disease, compared with those with those complications but without the metabolic syndrome (p = 0.01). CRP levels did not correlate with C-peptide levels in any patient group. Discussion > Higher C-peptide levels were associated with metabolic syndrome in patients with type 2 diabetes and in diabetes patients who also had nephropathy and vascular disease.