Metabolism in children

The most important component of the vital activity of the body is the metabolism, i.e. The ability of the body to take, process, maintain at some optimal levels and eliminate various chemicals. One of the functions of metabolism is the assimilation of food, its transformation into its own cells and tissues to ensure the energy needs of life, physical activity and growth.

The metabolic processes in children and adults consist of assimilation processes - the assimilation of substances entering the body from the environment, transforming them into simpler substances suitable for subsequent synthesis, the synthesis of substances themselves, or "blocks" - "details" for constructing one's own living matter or energy carriers, and from the processes of dissimilation - the splitting of substances that make up the living organism. The processes of synthesis of organic compounds (energy-consuming) are called anabolic (anabolism), the processes of splitting (forming energy) - catabolic (catabolism). Life is possible only with a constant and inseparable connection between the processes of splitting and synthesis, thanks to which the development and self-renewal of the organism is carried out.

[1], [2], [3], [4]

Features of metabolism in children

In children, during their growth and development, anabolic processes predominate over catabolic processes, and the degree of predominance corresponds to the rate of growth, which reflects the change in mass over a certain time.

The processes of metabolism in the human body are associated with certain structural formations. In mitochondria, most of the metabolic processes occur, especially oxidative and energetic processes (Krebs cycle, respiratory chain, oxidative phosphorylation, etc.). Therefore, mitochondria cells are often called "power stations" cells that supply energy to all of its other parts. In the ribosomes, proteins are synthesized, and the necessary energy for synthesis is obtained from the mitochondria. The main substance of protoplasm - hyaloplasm - takes a large part in the processes of glycolysis and other enzymatic reactions.

Along with cellular structures, tissues and organs created in the process of ontogenesis only once and for a lifetime, many cellular structures are not permanent. They are in the process of continuous construction and splitting, which depends on the metabolism. It is known that the life span of red blood cells is 80-120 days, neutrophils - 1-3 days, platelets - 8-11 days. Half of all plasma proteins are renewed in 2-4 days. Even bone substance and tooth enamel are constantly being updated.

The progressive development of the human body is determined by hereditary information, thanks to which proteins specific for each human tissue are formed. Many of the genetically determined proteins are part of the enzyme systems of the human body.

Thus, in essence all the metabolic processes are enzymatic and proceed sequentially, which is coordinated by a complex system of regulation chains with direct and reverse connections.

The child, in contrast to the adult, is the formation and maturation of metabolic processes, reflecting the general trend of development and maturation of the organism with all their disharmony and critical states. Environmental factors can act as inducers and stimulators of maturation of metabolic processes or entire functional systems. However, often the line between a positive, stimulating development of external exposure (or its dose) and the same impact with a devastating pathological effect can be very subtle. An expression of this is lability of metabolism, frequent and more pronounced disorders of it under various conditions of life or diseases.

[5], [6], [7], [8], [9]

Metabolic disorders in children

In children, metabolic disorders can be divided into three groups.

The first group of metabolic diseases is hereditary, genetically caused diseases, less often - anatomical developmental anomalies. As a rule, the basis for such metabolic diseases is the deficiency (of different expression) of the enzyme or enzymes necessary for the metabolization of a substance, and there is a stable unfavorable situation with the decomposition of the original food components, intermediate transformation or synthesis of new metabolites or elimination of the final products. Often, the deficit or excess of substances arising in conditions of altered metabolism have a very significant effect on the viability of the child or its physiological functions. Preservation of health or normal vital activity for such patients requires constant correction and care measures, often lifelong restrictions, substitution measures, clinical and laboratory monitoring, special food products. A significant proportion of genetically determined diseases or metabolic disorders may not appear clinically at all in childhood. Children - carriers of this pathological condition attract attention only in the adult period of life after the occurrence of relatively early or severe forms of vascular diseases (atherosclerosis of cerebral or heart vessels), hypertensive disease, chronic obstructive pulmonary diseases, liver cirrhosis, and so on. The relatively early detection of genetic or biochemical markers of these diseases is extremely effective in preventing their rapid progression during the adult period of life.

The second group is transient metabolic disorders. They are caused by a delay in the maturation of certain enzyme systems to the birth of a child or too early contact with that substance that is normally tolerated by children at an older age. We define this as disease, condition or reaction of maladaptation.

Children with a delay in the development of enzyme systems usually do not cope with the nutritional burden that most children suffer. One of these transient disorders is, for example, transient lactase deficiency, which is manifested by the frequent liquid stool of acid reaction and foamy species in the first 1 / 2-2 months of life. At the same time, children normally gain weight, do not have any visible abnormalities. Usually 2-3 months the chair is normalized, and even, on the contrary, the child suffers from constipation. Such conditions usually do not require the approaches necessary for genetically determined lactase deficiency. Some children of the first days of life with breastfeeding develop transient hyperphenylalaninemia, which disappears as the child grows. This group is predominantly somatic disorders, which are not hereditary. They can be interpreted as "critical states of development", as a physiological basis for reactions or states of maladaptation.

The third group is metabolic syndrome that occurs during various diseases or persists for a certain period after the disease (for example, malabsorption syndrome after intestinal infections). This is the most numerous group with which a doctor meets. Among them, lactase and saccharine deficiency is often observed, which determines the syndrome of prolonged (sometimes chronic) diarrhea after intestinal infections. Usually appropriate dietary measures allow to eliminate these manifestations.

It is possible that there is a very significant genetic basis in such transient states, since they are not detected in every child, but the degree of expression of this genetic predisposition for metabolic disorders is significantly lower than with constant food intolerance.