Endocrine Abstracts

A prerequisite milieu for normal growth is an intact hormonal system, adequate nutrition and normal physical activity. Any arm of this triangle, if interrupted, may change the normal growth pattern. Timing and interval range of disruption of this homeostasis, may affect the outcome up to irreversible results. The 3 polynomial growth model of Karlberg helps to detect, past irreversible growth retardation and in foresee and prevent growth deterioration

A normal function of the endocrine system from the gene to the receptor is dependent on an adequate supply of precursors, building materials, and functioning enzymes. Any substance, chemical that has the right configuration can activate a cascade of events in a different way from the expected normal function acting as an endocrine disruptor. On the other side of the spectrum, nutritional deficiency may result in hormonal deficiency.

We will use iron as an example for a nutritional basis of a hormonal dysfunction.

Iron deficiency may be the basis of an uncontrolled hypothyroidism, this specific deficiency results in malfunctioning of all the steps of the TRH-TSH-T4 axis. The last step of the iron dependent thyroid peroxidase may prevent efficient production of thyroid hormone. Without proper replacement of iron, thyroxin replacement may be inefficient and reaching euthyroidism may be a difficult task. Iron deficiency may be the tip of the iceberg of nutritional deficiency. In such a patient, subnormal Vitamin A levels may interfere with iron supplementation, since vitamin A has an important task in iron absorption. Hypothyroidism may be severe in patients with a combination of iron and vitamin A deficiency. During puberty as a result of subnormal vitamin A supply, puberty might be delayed and growth hormone levels may be lower than expected. Thus adequate nutrition is a prerequisite for a normally functioning hormonal system for proper growth and puberty.

Physical activity may have an effect on nutritional needs but also an effect on metabolic systems. In children and adolescents, IGF-I levels may be low despite adequate supply of calories in first stages of training. While sedentary life style and caloric overload may change pubertal progression and growth.

In a world of super specialty, clinical cases teach us that endocrinology and nutrition have many very important meeting points of interest.