PECULIARITIES OF PROTEIN, LIPID, AND CARBOHYDRATE METABOLISM IN PRETERM INFANTS: ANALYSIS OF INDICATORS AND PATHOPHYSIOLOGICAL MECHANISMS OF DISORDERS

Abstract

The aim of the study – to study the indicators of protein, lipid, and carbohydrate metabolism in preterm infants to clarify the pathophysiological mechanisms of digestive system disorders in perinatal pathology.

Materials and Methods. A comprehensive examination of 96 preterm infants was carried out, of which the leading group consisted of 68 newborns with a gestational age of 32 to 34 weeks who had severe adaptation disorders due to perinatal pathology, and the comparison group consisted of 27 conditionally healthy children born at a gestational age of 34 to 37 weeks. The inclusion criteria were: gestational age of newborns from 32 to 34 weeks, signs of severe perinatal pathology; exclusion criteria were: gestational age at birth less than 32 weeks and 37 weeks or more, congenital malformations, and septic conditions.

A comprehensive clinical and laboratory examination of newborns with a dynamic assessment of the severity of the condition during the neonatal period was performed. The list of diseases is defined according to the International Classification of Diseases, X Revision. Additional methods of paraclinical examination included serum biochemical analysis, in particular: total protein, glucose, urea, cholesterol, and triglycerides; trypsin, amylase, and lipase enzymes. The experiments were performed based on the educational and research laboratory of the Bukovyna State Medical University (BSMU) of the Ministry of Health of Ukraine and the German-Ukrainian laboratory "BUKINMED" (Chernivtsi, Ukraine). List of equipment used: biochemical analyzer ADVIA®KC 1800/2400 Chemistry System (Siemens Healthcare Diagnostics, USA), automatic biochemical analyzer Accent 200. Scientific research was carried out in compliance with the basic provisions of GCP (1996), the Council of Europe Convention on Human Rights and Biomedicine (April 4, 1997), the World Medical Association Declaration of Helsinki on the Ethical Principles for Research Involving Human Subjects (1964-2008), Order of the Ministry of Health of Ukraine No. 690 of 23.09.2009 (as amended by Order of the Ministry of Health of Ukraine No. 523 of 12.07.2012), Protocol of scientific research of the Commission on Biomedical Ethics of BSMU dated 12.09.2015. Informed consent was obtained from the parents of newborns after familiarization with the purpose, objectives, and methods of laboratory tests. Statistical processing of the results was performed using the software "STATISTICA" (StatSoft Inc., USA, Version 10), MedCalc program (https://www.medcalc. org/index.php). The comparison of quantitative indicators with a normal distribution was performed using Student's t-test; the probability of differences was considered statistically significant at p<0.05.

Results and Discussion. The biochemical parameters of blood serum in preterm infants with clinical manifestations of perinatal pathology were evaluated, and the role and nature of metabolic disorders in the body were analyzed, taking into account the main pathophysiological mechanisms of their development. The obtained results showed that severe forms of perinatal pathology are accompanied by a significant decrease in the level of total protein – 53.5±0.86 g/l and 54.7±1.56 in the control group, respectively (p<0.05), which may indicate both insufficiency of the protein-synthesizing function of the liver and increased protein intake in the body under conditions of postnatal adaptation. Compared to the control group, a significantly higher level of urea was found – 11.3±0.82 and 5.9±0.44 mmol/l (p<0.05), respectively, confirming the increased breakdown of proteins in newborns under birth stress. Significantly higher cholesterol levels were found – 3.5±0.37 mmol/l and 2.2±0.15 mmol/l in the control group, respectively (p<0.05), indicating significant lipid metabolism disorders. Under severe disease conditions, a significantly lower serum glucose level was noted – 2.4±0.12 and 3.3±0.30 mmol/l, respectively, compared with control values (p<0.05). Preterm infants are characterized by a significant decrease in enzymatic activity; in particular, a decrease in trypsin activity was found – 354.2±17.71 μg/l and 423.0±21.13 μg/l, respectively, compared to the control group (p<0.05); lipase – 16.5±0.83 and 20.3±1.02 un/l (p<0.05) and amylase – 8.2±0.40 and 25.0±1.24 un/l, respectively (p<0.05).

Conclusions. Premature birth of children under conditions of hypoxia is an unfavorable factor in the development of perinatal pathology, an essential manifestation of which is a violation of the functional state of the digestive system, which causes significant problems in the establishment of complete enteral nutrition. Indicators of biochemical analysis of newborn blood serum indicate significant abnormalities in protein, lipid, and carbohydrate metabolism, which confirms the presence of significant metabolic disorders in the body in the setting of perinatal pathology. To some extent, reduced pancreatic enzymatic activity in terms of trypsin, lipase, and amylase explains the pathophysiological mechanisms of food intolerance in preterm infants, which requires appropriate attention when creating individualized intensive care programs.