Serum Copeptin as a Biomarker of Polycystic Ovarian Syndrome and its Correlation with Metabolic Syndrome Components: A Cross-sectional Analytical Study

Abstract

Introduction: Approximately 5 to 10% of women of reproductive age suffer from the prevalent endocrine illness known as Polycystic Ovarian Syndrome (PCOS). Copeptin, irrespective of age and weight, has been found to have significant associations with cardiometabolic parameters. Studies on the diagnostic and prognostic significance of copeptin and its correlation with components of metabolic syndrome in PCOS are scarce, particularly in the Indian context. Aim: To assess the utility of copeptin as a diagnostic marker of PCOS and to evaluate the correlation of serum copeptin levels with metabolic syndrome components in women with PCOS. Materials and Methods: This cross-sectional analytical study was conducted at Father Muller Medical College Hospital, Mangalore, Karnataka, India, from June 2022 to September 2023. A total of 60 subjects with PCOS were selected through convenient sampling and divided into two groups: Group 1-subjects with PCOS having metabolic syndrome, and Group 2-subjects with PCOS but not having metabolic syndrome. Blood samples for serum copeptin were taken under aseptic precautions, and levels were analysed using a commercially available Enzyme-Linked Immunosorbent Assay (ELISA) kit (Biovendor, USA) following the manufacturers’ instructions. The copeptin ELISA kit had an assay range of 0-100 pmol/L and results were expressed in ng/mL. Serum insulin levels were measured using specific Electro-chemiluminescence immunoassays. Levels of total cholesterol, High-Density Lipoprotein Cholesterol (HDL-C), and Triglycerides (TG) were determined with enzymatic colorimetric assays by spectrophotometry. Low-Density Lipoprotein Cholesterol (LDL-C) was calculated using the Friedewald formula. Insulin resistance was calculated using the Homeostasis Model Assessment Insulin Resistance Index (HOMA-IR). Statistical analysis was done by using descriptive statistics. A comparison was done by student’s unpaired t-test. The chi-square test and Pearson correlation test were used for categorical data. The Statistical Package for Social Sciences (SPSS) version 24.0 was used for analysis. Results: The mean age of the study participants was 24.24±4.721 years, ranging from 15 to 43 years. The mean age of patients with metabolic syndrome was 23.96±6.3 years, while those without metabolic syndrome was 24.40±3.52 years. The mean Body Mass Index (BMI) was 31.17±5.38 in those with metabolic syndrome and 23.2±4.7 in those without (p=0.0001). The Waist-to-Hip Ratio (WHR) of Group 1 was significantly higher than Group 2 (p=0.001). The two groups did not differ significantly with regard to serum copeptin level, i.e., 7.386±4.58 in Group 1 and 8.66±6.03 in Group 2 (p=0.736). Serum copeptin levels showed a significant correlation with fasting serum insulin (0.006) and Homeostatic Model Assessment - Insulin Resistance (HOMA-IR) (0.012). Conclusion: Serum copeptin cannot be used as an independent marker for the diagnosis of metabolic syndrome in PCOS patients but may indicate other prognostic factors.

Keywords

• copeptin
• metabolic syndrome
• polycystic ovarian syndrome