BACKGROUND: Insulin resistance with increased insulin and C-peptide levelsis the basis of the metabolic X-syndrome, so it is reasonable to expect them to be a good predictor ofassociated cardiovascular risk factors. MATERIAL/METHODS: A total of 29 patients (21 postmenopausal womenand 8 men) with type 2 diabetes mellitus (mean duration 14.6 years, 95% CI 11.9 to 17.3 years), all olderthan 50, were studied for possible links between fasting serum C-peptide levels and other vascular riskfactors. The mean value of the C-peptide in the group was 0.627 nmol/l (95% CI: 0.464 to 0.789 nmol/l).RESULTS: We found statistically significant correlations between C-peptide and triacylglycerols (TG;r=0.474; p=0.009), HDL-cholesterol (inverse; r = -0.567; p = 0.001) and various lipoprotein ratios: atherogenicindex (= total/HDL cholesterol: r = 0.599; p = 0.0006) or TG/HDL (r = 0.587; p = 0.0008). C-peptide alsocorrelated with the body mass index (BMI: r = 0.519; p= 0.004) and leptin (r = 0.492; p = 0.007). Afterthe coefficient CpG (C-peptide x fasting glycemia) was introduced, the correlations with lipoproteinsbecame even stronger. CONCLUSIONS: We suggest that elevated (fasting) serum C-peptide levels constitutea clinically important marker of the cardiovascular risks associated with the metabolic X-syndrome. Itcan be used as an effective tool for the early detection of diabetic patients at particular risk foratherosclerotic cardiovascular diseases and needing early preventive measures or aggressive treatment.

Keywords: C-peptide, Cardiovascular Diseases, Diabetes Mellitus, Type 2, Hyperlipoproteinemia, Insulin, Insulin Resistance, Lipoproteins, Metabolic Syndrome X, Peptides, Postmenopause, Risk Factors