Adrenal function of low-birthweight children.

During the neonatal period, increased stress due to infection or illness in low-birthweight infants may increase the importance of adequate adrenal cortisol secretion. Such low-birthweight infants often have transient cortisol insufficiency during the first few days of life, but then soon develop restored or even high cortisol levels. The pressure to enhance survival during this critical period could lead to either the programming of higher cortisol secretion, or the favorable selection of infants who are genetically predisposed to produce sufficient cortisol levels and activity. However, in long-term survivors of low birthweight, the maintenance of higher levels of cortisol secretion or action may contribute to increased hypertension and cardiovascular disease risk in later life. Similarly, low birthweight and subsequent rapid postnatal weight gain are associated with increased androgen secretion from the adrenal zona reticularis and this may contribute to disorders of hyperandrogenism and hyperinsulinemia before and after puberty. Precocious pubarche, the clinical manifestation of adrenal hyperandrogenism prepuberty, in girls is predictive of polycystic ovary syndrome, and is also associated with dyslipidemia, and increased central fat. In conclusion, long term consequences of low birthweight on both adrenal cortisol and adrenal androgen secretion could contribute to increased risks for the metabolic syndrome in later life.