Influence of fetal growth velocity and smallness at birth on adrenal function in adolescence

The hypothalamic-pituitary-adrenal axis is susceptible to programming during fetal development and may be linked to risk of disease later in life. In a former prospective study the cohort was divided into those born appropriate for gestational age (AGA) or small for gestational age (SGA; birth weight <10 percentile). In 52 adolescent boys (17.5 years) we assessed circulating androgen levels (T, Δ ⁴-adione, DHEAS), overnight serum cortisol profiles (every 20 min), ACTH stimulation test (250 μg i.v.) and analysis of 24-hour urinary adrenal steroid excretion. Urinary excretion of adrenal androgen and cortisol metabolites were significantly lower in the SGA compared to the AGA group. Basal morning cortisol levels were lower in adolescents born SGA compared to those born AGA (365 mmol/l, interquartile range (IQR) 284-413 vs. 445 mmol/l, IQR 377-495, p = 0.04), but overnight cortisol profiles (AUC) did not differ. The ACTH test showed equally stimulated levels of cortisol for those born SGA and AGA. There was no difference in serum testosterone, dehydroepiandrosterone sulfate and Δ ⁴-adione levels between the SGA and AGA subjects. This suggests impaired excretion of adrenal androgen and cortisol metabolites in young men born SGA compared to AGA. In conclusion, this study demonstrated subtle changes in adolescent adrenal function associated with birth weight.