COMPARISON OF PHOENIXIN-14 LEVELS IN UMBILICAL CORD BLOOD ACCORDING TO BIRTH WEIGHT IN TERM INFANTS: ARE PHOENIXIN-14 LEVELS LINKED TO BIRTH WEIGHT AND MATERNAL DIABETES?

INTRODUCTION Birth weight and pregnancy week are determinants of mortality and morbidity of newborn infants. Birth weights by gestational week are associated with accompanying diseases in the later stages of life (1). Infants with a birth weight below the 10th percentile by gestational week are defined as small for gestational age (SGA), those with a birth weight above the 90th percentile are defined as large for gestational age (LGA), and those with a birth weight between the 10th and 90th percentiles are defined as appropriate for gestational age (AGA) (2). In LGA and SGA infants, problems such as hypoglycemia, hypoxia, polycythemia, and respiratory support may be encountered in the neonatal period. These infants may also experience diseases that affect the quality and duration of life at later ages, such as metabolic syndrome, obesity, cardiovascular diseases, and diabetes mellitus (1, 2). Gestational diabetes mellitus (GDM) is the most common complication during pregnancy and is defined as any degree of glucose intolerance that begins or is first recognized during pregnancy (3). GDM has long been associated with obstetric and neonatal complications, particularly those related to high birth weight, and is increasingly recognized as a risk factor for future cardiometabolic disease in the child. As the causes of serious health problems can be attributed to maternal illness or changes in birth weight, these issues continue to be investigated (4).

Phoenixin (PNX) is a neuropeptide first described by Yosten et al. in 2013 (5). The most common isoforms of PNX, phoenixin-14 (PNX-14) and phoenixin-20 (PNX-20), exhibit similar biological activities and are peptides composed of 14 and 20 amino acids, respectively (5). In the initial characterization of PNX, it was reported to be crucial for normal reproductive function through its effects on the hypothalamus-pituitary-gonadal axis. The literature provides further evidence for the role of PNX in reproductive functions and suggests that it also plays a role in other aspects of brain-mediated and peripheral physiology. In addition, there is some evidence demonstrating that PNX affects the heart, diet, memory, and anxiety (6). Animal studies of PNX-14 have shown that PNX-14 has an important role in the central control of feeding behavior and metabolic homeostasis. In addition to correlations between PNX-14 and body mass index (BMI), studies have shown that PNX-14 modulates food intake and feeding behavior (7). PNX-14 is a neuropeptide known to prevent oxidative damage and stimulate insulin secretion. Animal studies have shown that PNX-14 treatments prevent pancreatic damage and β-cell loss by reducing oxidative stress (8). A study indicating that PNX-14 plays an important role in the occurrence of diabetes and obesity found that PNX-14 concentrations were significantly lower in patients with type 2 diabetes mellitus than in healthy individuals (9, 10).

In this study, we investigated the relationships between normal (AGA), low (SGA), and high (LGA) birth weight according to gestational week of pregnancy and phoenixin-14 levels in the umbilical cord blood of healthy infants of healthy mothers and infants of mothers diagnosed with GDM regardless of birth weight.

MATERIALS AND METHODS We obtained approval for this prospective study from the Karatay University Ethics Committee (Ethics Committee Decision No: 2022/005) and Konya City Hospital. We conducted the research between December 2022 and April 2024 at Konya City Hospital in the Department of Obstetrics and Gynecology, the Neonatal Intensive Care Unit, and the Department of Medical Biochemistry (Clinical Trials ID: NCT).

Patients Infants with multiple congenital anomalies, chorioamnionitis, and preeclampsia; infants who were born after premature rupture of membranes; infants who needed intensive care; and otherwise ill or premature infants were excluded from the study. Infants whose mothers had any disease other than diabetes were also excluded. Healthy term infants (born between 370/7 and 426/7 weeks) born by spontaneous vaginal delivery or cesarean section were included in the study. The demographic and neonatal data and the PNX-14 levels of the patients included in the study were recorded.