Among babies born at term, intrauterine growth retardation (IUGR) predicts adult hypertension and hyperglycaemia. This might be due to elevated circulating glucocorticoids in adulthood, as described in animal models and in several cohorts of men who were low birthweight at term. Recently, we found that premature low birthweight babies also have adult cardiovascular risk factors, irrespective of IUGR. We have now investigated cortisol secretion in this group. DESIGN PATIENTS AND MEASUREMENTS: We studied 29 women and 23 men aged 22-25 years who had been recruited at birth as either normal term (mean birthweight 3.1 kg, gestation 39 weeks), premature appropriate for gestational age (AGA; 1.7 kg, 32 weeks), or premature IUGR (1.7 kg, 35 weeks) babies. Body composition was measured by dual-energy X-ray absorptiometry (DEXA); plasma was obtained at 0900 h after overnight fast; and cortisol metabolites were measured in a 24-h urine sample by gas chromatography/mass spectrometry (GCMS).