Evaluation of MANF and MOTS-c Levels in Women With Gestational Diabetes Mellitus and Healthy Pregnant Women: A Prospective Cohort Study

Background: Gestational diabetes mellitus (GDM) is a common pregnancy complication characterized by metabolic stress and mitochondrial dysfunction, for which reliable circulating biomarkers are still lacking. This study aimed to investigate serum mesencephalic astrocyte-derived neurotrophic factor (MANF) and mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) levels in women with GDM and to compare them with levels in healthy pregnant and non-pregnant women. We also sought to identify potential associations with metabolic and demographic parameters. Methods: This prospective cohort study was conducted from January 2025 to May 2025 and enrolled three groups: women with GDM, healthy pregnant women, and healthy non-pregnant women. Age, anthropometric data, and routine biochemical parameters, including fasting glucose, insulin, hemoglobin A1c (HbA1c), alanine aminotransferase (ALT), creatinine, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides, were assessed. Serum MANF and MOTS-c levels were also measured. Results: The GDM group was significantly older (33.2 ± 5.6 years) than the healthy pregnant (29.3 ± 4.5 years) and non-pregnant control groups (28.6 ± 5.2 years) (p = 0.011). MANF levels were significantly lower in pregnant women compared with controls (p < 0.001), whereas MOTS-c levels were significantly higher (p < 0.001). Receiver operating characteristic (ROC) analysis demonstrated limited discriminatory ability of MANF (area under the curve [AUC] = 0.567, p = 0.301) and MOTS-c (AUC = 0.604, p = 0.111) in distinguishing women with GDM from healthy pregnant women. Furthermore, within the GDM group, MANF and MOTS-c levels were not associated with age, height, weight, body mass index (BMI), waist circumference, glucose, insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), lipid profile, or liver enzyme levels. Conclusions: This study shows that MOTS-c levels increase and MANF levels decrease during pregnancy, but neither is associated with GDM, indicating pregnancy-related metabolic changes rather than GDM-specific alterations. Although they are not useful for GDM diagnosis, these peptides may provide insight into novel metabolic pathways and hold therapeutic potential in high-risk pregnancies. Study Registration: The study has been registered on https://zenodo.org/ (registration link: https://doi.org/10.5281/zenodo.18776009).