A molecular link between normal Pregnancy and Gestational diabetes mellitus in local population.

Objective: To assess the differential expression of miR-16-5p and associated biochemical markers in pregnancies complicated by gestational diabetes mellitus (GDM) compared to normal pregnancies. Methods: This cross-sectional comparative study included 80 pregnant women including 40 women with GDM and 40 age-matched healthy controls during their second and third trimesters. Participants were recruited from Lady Aitchison Hospital and Services Hospital, Lahore through random sampling from April 2021 to June 2022. Serum levels of insulin, insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-1 (IGFBP-1), tumor necrosis factor-alpha (TNF-α), and glutathione peroxidase (GPX) were measured using ELISA kits. miRNA was extracted from whole blood, and miR-16-5p expression was quantified using real-time polymerase chain reaction (PCR), with fold change calculated through the Livak method. Statistical analysis were conducted using IBM SPSS v26.0. Normality of the data was assessed with the Shapiro-Wilk test; Group comparisons were performed with the Mann-Whitney U test due to non-normal distribution of most variables, and associations of biochemical markers with miR-16-5p were evaluated using Spearman's rank correlation. Results: GDM patients exhibited significantly higher serum glucose, insulin levels, and miR-16-5p expression (p < 0.001) compared to controls. Conversely, IGF-1, IGFBP-1, TNF-α, and GPX levels were elevated in the control group. In the GDM cohort, miR-16-5p expression positively correlated with glucose levels (r = 0.411, p = 0.008) and negatively with GPX levels (r = -0.450, p = 0.004). Conclusion: GDM-related pregnancies show significant differences in glucose, insulin, and TNF-α levels, with altered miRNA expression potentially serving as noninvasive biomarkers.