Roles of C-Peptide and Triglyceride as Effective Indices for Insulin Resistance Investigations in Iraqi Women with Polycystic Ovarian Syndrome

Abstract

Objectives: To assess how much Insulin Resistance (IR) in both obese and non-obese PCOS women used as index of PCOS and find out a correlation between various methods used for evaluation of IR.
Methods: A study included 120 participants (68 women have PCOS subdivide according to their BMI to 45 obese (BMI>=30) and 23 non-obese (BMI<30). The remaining 52 participants represent as apparently control group with normal weight and normal menstrual cycle. Patients with PCOS were selected from the Infertility Department, Gynecology and Obstetrics Teaching Hospital in Kerbala, Iraq between Nov., 2021 and June, 2022. Diagnosis of PCOS is based on 2 of 3 findings: oligo/anovulation, hyperandrogenism, polycystic ovaries in ultrasound (Rotterdam criteria). Patients were interviewed and examined for weight, height, waist and hip circumferences. Venous blood samples were collected and insulin resistance was assessed by different methods including homeostatic model assessment of insulin resistance (HOMA-IR), G/I ratio, QUICKI, McAuly, TyG index and C-peptide index.
Results: The assessment of IR revealed that HOMA-IR, QUICKI, McAuley, TyG and CPI had significant difference in both PCOS groups compared with controls. G/I ratio was significantly higher in the controls than obese PCOS women. The prevalence of IR based on (HOMA-IR) was 80% in obese PCOS and 48% in non-obese PCOS women. In obese PCOS women HOMA-IR strongly and negatively correlates with G/I ratio (r= -0.81, P<0.001), QUICKI (r= -0.89, P<0.001), McAuley (r= -0.79, P<0.001) and C-peptide (r= -0.56, P<0.001). Whereas it was positively correlates with insulin (r=0.99, P<0.001), C-peptide (r=0.71, P<0.001) and TyG index (r=0.51, P<0.001). In non-obese PCOS women, HOMA-IR strongly and negatively correlates with G/I ratio (r= -0.79, P<0.001), QUICKI (r= -0.93, P<0.001) and McAuley (r= -0.77, P<0.001). Whereas it was positively correlates with insulin (r=0.99, P<0.001), C-peptide (r=0.49, P<0.05) and TyG index (r=0.47, P<0.05).
Conclusion: The observed results concluded that TyG is a valuable indicator to predict IR in obese women with PCOS, partly due to its analytical and financial ease-of-access in all clinical laboratories. The use of TyG index is recommended in the assessment of IR risk among Iraqi women with PCOS.