Associations of C-peptide with cardiometabolic parameters in women aged 25–44 years with different metabolic phenotypes

Abstract

The development of atherosclerotic diseases is pathogenetically associated with an increase in insulin resistance, an indirect marker of which is the C-peptide. In addition, literature data indicate the intrinsic proatherogenic effects of C-peptide. In recent years, the concept of separating metabolically healthy (MHP) and unhealthy phenotype (MUHP) at different body weights has become increasingly widespread. It believed that the key difference between MHP and MUHP is the more pronounced insulin resistance in the latter, but there are no clear data on the association of C-peptide with MHP or MUHP. Aim of the study was to investigate the association of C-peptide level with different metabolic phenotypes in women aged 25–44 years. Material and methods. The study was conducted on the basis of a representative sample of women aged 25–44 years (n = 1513, of which 840 women). The analysis included indicators of 655 women. The definition of MHP and MUHP carried out using the IDF criteria, 2005 for the diagnosis of metabolic syndrome. Anthropometric measurements, biochemical and hormonal blood tests have been carried out in groups divided by the body mass index (BMI). The level of C-peptide was determined by the method of multiplex analysis. Results. C-peptide content in the examined sample was 0.9 [0.5; 1.3] ng/ml (Me [Q1; Q3]), with MHP – 0.8 [0.5; 1.1] ng/ml, with MUHP – 1.3 [0.7; 1.8] ng/ml, p < 0.0001. With an increase in BMI, the median of C-peptide increased both in MHP (from 0.8 [0.4; 1.1] to 1.2 [0.8; 1.7] ng/mL, ptrend < 0.0001) and with MUHP (from 0.8 [0.2; 1.2] to 1.5 [0.9; 2.1] ng/mL, ptrend = 0.006). The frequency of MUHP in the 4th quartile of the C-peptide is 2.7 times higher than in the 1st quartile (p < 0.0001), and the frequency of MHP – 1.6 times lower (p = 0.001). C-peptide content correlated with anthropometric parameters, glucose, lipid concentration, transaminase activity, kidney filtration capacity. A C-peptide level of more than 1.33 in young women indicates a high probability of having MUHP with maximum sensitivity and specificity (Se = 49.3 %, Sp = 85.9 %). Conclusions. In women with MUHP, C-peptide content is 38.5 % higher than in women with MHP. The frequency of MUHP in the 4th quartile of the C-peptide is 3.2 times higher than in the 1st quartile. The level of C-peptide above 1.33 ng/ml is associated with the presence of MUHP.