Association of Serum Cystatin C with Glycaemic Parameters and Insulin Resistance in Pregnant Women with Gestational Diabetes Mellitus

Cystatin C and Insulin Persistence

Abstract

Background: Gestational Diabetes Mellitus (GDM) is a common metabolic complication of pregnancy characterized by glucose intolerance and insulin resistance. Early detection and management of GDM are critical to prevent adverse maternal and foetal outcomes. Cystatin C; traditionally known as a renal marker, has recently been implicated in metabolic dysfunctions such as insulin resistance and hyperglycaemia.

Objective: This study aimed to evaluate the association of high serum Cystatin C with glycaemic parameters and insulin resistance in pregnant women with GDM.

Methods: This case-control study was conducted at Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) General Hospital, Dhaka, from March 2024 to February 2025. Total 160 pregnant women between 24–28 weeks of gestation were enrolled; including 80 diagnosed GDM (cases) and 80 age and gestational week matched healthy pregnant women (controls). Selection was done using convenient and purposive sampling. GDM was diagnosed based on the American diabetes association (ADA) 2023 criteria. Clinical, anthropometric, and biochemical parameters, including fasting plasma glucose, 2-hour post-load plasma glucose, serum insulin, HOMA-IR, and serum Cystatin C, were measured. Data were analysed using SPSS version 26, with p < 0.05 considered statistically significant.

Results: The mean BMI was significantly higher in the GDM group (28.97 ± 3.75 kg/m²) compared to controls (27.97 ± 4.04 kg/m², p < 0.002). Fasting plasma glucose (5.92 ± 2.14 mmol/L vs. 4.41 ± 0.40 mmol/L, p < 0.001), 2-hour post load plasma glucose (9.03 ± 2.92 mmol/L vs. 6.53 ± 1.02 mmol/L, p = 0.041), and HOMA-IR (5.87 ± 3.94 vs. 3.99 ± 1.78, p < 0.001) were significantly elevated in the GDM group. Serum insulin was higher among cases but not statistically significant (p = 0.38). Serum Cystatin C level was significantly elevated in the GDM group (0.932 ± 0.23 mg/L vs. 0.734 ± 0.11 mg/L, p < 0.001). The high level (>0.80 mg/dl) serum Cystatin C was strongly associated with GDM (OR-9, CI-5.0 to 16.3, p< 0.001). Cystatin C was positively correlated with fasting plasma glucose (r = 0.321, p <0.05); 2-hour post load plasma glucose (r = 0.303, <0.05) and HOMA-IR (0.323, P< 0.05). Correlations of Cystatin C with serum insulin (r = 0.121, p>0.05) and BMI (r = 0.150, p>0.05)) were positive but not statistically significant.

Conclusion: High serum Cystatin C levels exhibit strong, positive, and statistically significant association with the presence of GDM and a positive correlation was found with glycaemic parameters and insulin resistance. So, woman with elevated Cystatin C suggest a higher risk of developing GDM.

Bangladesh Medical Res Counc Bull 2025;51(3): 117-122