Adiponectin - hormone regulating infantile development: current state of knowledge

Adiponectin is a cytokine built with 244 amino acids. It is produced and secreted by adipose tissue. The concentration of this hormone in serum fluctuates from 1 to 30 mg/ml. The main function of this cytokine is the control of metabolism, carbohydrates and lipids. Women have higher concentration of adiponectin than men. Its high concentration is observed in those suffering from anorexia and bulimia. Its reduced concentration decreases insulin levels, and leads to the development of diabetes and lipodystrophy. It is believed that low adiponectin level contributes to the development of atherosclerosis and cardiovascular complications including unstable coronary artery disease. Mechanisms of synthesis regulation have not been thoroughly understood. One describes only the increase of adiponectin gene expression regulated by receptors activated by peroxisome proliferation. Adiponectin is present in breast milk where it plays an important role in the development of the infant. The newborn has higher adiponectin level than the adult; it correlates with the maturity of foetus and its body weight. Full-term newborns with normal birth weight have higher concentration of adiponectin than the premature infants and newborns with low birth weight. Infants with macrosomia have lower concentration of this hormone than children with normal and low birth weight, despite their similar BMI. In the prepubertal age, the value of adiponectin is a good indicator of insulin resistance. Changes in the concentration of adiponectin in foetuses and newborns, under the influence of not fully explained factors, may affect their development and lead to childhood obesity. In the first year of life, there is a progressive decrease in the concentration of this hormone.