Fasting plasma C-peptide correlates with body mass index, hsCRP, apolipoprotein B, and other atherogenic lipids in healthy individuals.

C-peptide has a complex role in human physiology, but its effects are not fully understood. Studies have shown a protective impact against diabetic complications, but also that C-peptide levels associate with cardiovascular events. Among the many applications to assess cardiovascular risk, circulating lipids are widely used, and one of the strongest biomarkers is apolipoprotein B. The aim of this investigation was to study the association of C-peptide with markers of metabolic, inflammatory, or cardiovascular alterations in a limited group of healthy individuals. Body mass index (BMI), lipids, and other plasma markers were studied in 28 consecutive healthy individuals within the age of 30-50 years. The results showed significant positive correlations between C-peptide and BMI (r = 0.498; p = 0.007); hsCRP (r = 0.530; p = 0.004); triglycerides (r = 0.530; p = 0.005); cholesterol (r = 0.507; p = 0.006), LDL-cholesterol (r = 0.550; p = 0.002), LDL/HDL ratio (r = 0.460; p = 0.014); apoB (r = 0.622; p < 0.001), apoB/apoA1 ratio (r = 0.563; p = 0.002); and non-HDL cholesterol (r = 0.566; p = 0.002). According to BMI values, 16 of the 28 individuals were overweight (BMI >25.0 kg/m). If overweight individuals were excluded, C-peptide did only correlate with apoB (r = 0.636; p = 0.026). To conclude, C-peptide within normal levels associate with BMI and atherogenic lipids in healthy individuals, and apoB associate with C-peptide even at normal weight. These results suggest that C-peptide can be an early additional cardiovascular risk marker.