Can Albumin/C-reactive Protein Ratio be Utilized for Predicting Gestational Diabetes Diagnosis or the Adverse Outcomes

Introduction

Pregnancy necessitates a fine balance between pro- and anti-inflammatory processes to establish a favorable uterine environment. Disruptions in this balance, such as inflammation, are associated with adverse outcomes, including gestational diabetes mellitus (GDM). GDM prevalence varies globally, influenced by ethnicity, diagnostic criteria, and cultural differences, ranging from 1% to 28%. In Europe, the prevalence is approximately 5-10%, posing significant risks for maternal and neonatal health. Universal screening between 24-28 weeks of gestation is widely recommended.

Primary GDM risk factors include advanced maternal age, obesity, and inflammation. Adipose tissue, an endocrine organ, secretes adipokines such as leptin and adiponectin, which impact glucose metabolism, particularly in obesity-related insulin resistance. Pregnancy-induced insulin resistance ensures fetal glucose supply, but insufficient pancreatic beta-cell compensation may lead to GDM. These mechanisms underscore the rationale for mid-gestation GDM screening.

Although glucose tolerance tests are considered safe, concerns about glucose ingestion during pregnancy highlight the need for innovative diagnostic approaches. Given GDM's inflammatory underpinnings, markers of acute inflammation could enhance diagnostic accuracy. This study evaluates the albumin/high-sensitivity C-reactive protein (hsCRP) ratio's utility in diagnosing GDM and predicting adverse outcomes.

Material and Methods

Study Design and Participants

This prospective clinical cohort study was conducted at a training and research hospital with ethics committee approval. Pregnant women at 24-28 weeks of gestation, determined by last menstrual period and first-trimester ultrasonography, were enrolled. The study adhered to the Declaration of Helsinki principles, with participants providing written informed consent for data collection and analysis.

GDM Screening and Diagnosis

The glucose challenge test (GCT) measured plasma glucose one hour after consuming 50 grams of glucose. Participants with GCT results ≥140 mg/dL underwent a 100-gram oral glucose tolerance test (OGTT) after a standardized three-day diet. OGTT diagnostic criteria included fasting plasma glucose (FPG) levels and glucose measurements at 1-hour and 2-hour intervals post-glucose ingestion, categorized per Carpenter and Coustan criteria. Some participants underwent 75-gram OGTT, with diagnostic thresholds similarly defined.

Laboratory Measurements

Blood samples were analyzed in the hospital laboratory. Albumin levels were measured using the bromocresol green method, and hsCRP levels were assessed using nephelometry. The albumin/hsCRP ratio was calculated accordingly.

Exclusion criteria

Participants with pre-gestational diabetes, BMI >30, age >35, GDM history, macrosomic delivery history, unexplained fetal loss, type II diabetes family history, endocrinology diseases, liver or renal disease, or systemic/local infection were excluded.

Data Collection and Review

Antenatal visit records and delivery outcomes were reviewed for complications, including preeclampsia, gestational hypertension, amniotic fluid abnormalities, fetal anomalies, preterm labor, and postpartum hemorrhage. Neonatal outcomes, such as birth weight, APGAR scores, NICU admission, and stillbirth, were also assessed.

Statistical Analysis

The Shapiro-Wilk test assessed variable normality. Normally distributed variables were compared using Student's t-tests; non-normally distributed variables were analyzed with Mann-Whitney U tests. Categorical variables were compared using Chi-square or Fisher's exact tests. ROC curve analysis evaluated the albumin/hsCRP ratio's predictive potential, reporting AUC, sensitivity, specificity, and cut-off values. Analyses were performed using SPSS 22 and MedCalc 19.5.6, with p<0.05 considered significant.

Inclusion criteria

• Pregnant women between 24 and 28 weeks of gestation.
• Gestational age confirmed by both last menstrual period and first-trimester ultrasonography.
• Signed informed consent for data collection, analysis, and use for research.

Exclusion criteria

• Pre-gestational diabetes mellitus.
• BMI > 30.
• Age > 35 years.
• A history of gestational diabetes mellitus (GDM).
• Previous delivery of macrosomic infants.
• Unexplained fetal loss.
• Family history of type II diabetes mellitus.
• Any endocrinological disease.
• Liver disease, renal disease, or other significant systemic or local infections.