Urinary excretion of adrenocortical steroid metabolites by pre-term human infants: trends from birth until 3 months post term.
We report trends in urinary steroid excretion in serial 24 hour collections made using a novel method based on "Supersorb" type disposable nappies. Using capillary column gas chromatography, we quantified nine cortisol metabolites (FM) and 11 steroid sulphates (SM) in 6 infants born at 29-31 weeks gestation on 9 occasions until 24 weeks post delivery. In all infants, SM excretion increased progressively until 33-39 weeks (mean 36.8) post conception to maxima of (all values mg/24 h) 2.6-11.7 and then declined to 5-15% of peak values at the end of the study period in 4 infants born after a period of labour but to only 54 and 71% in 2 infants born without labour. FM levels showed a wide range which was not correlated with body weight, eg: on week 1, 0.06-0.20 and on week 24, 0.15-0.72. progression over this period was essentially linear. The ratio (mean (SD)) of 11-oxo/11-hydroxy metabolites decreased from 10.0 (8.2) to 2.3 (0.4) in the same period, p = < 0.10, while that of 20-oxo/20-hydroxy metabolites increased from 0.18 (0.07) to 1.08 (0.42), p = < 0.04. The ratio of metabolites with 5 oxygen functions relative to 6 increased from 0.38 (0.16) to 1.36 (0.43), p = < 0.04. Excretion of 5 alpha-tetrahydrocortisol began to rise at 44-47 wk post conception, but, unexpectedly, that of the 5 beta epimer began to rise sooner, at 39-41 wk, reaching a peak at 44-51 wk and then declining. The ratio of 5 beta/5 alpha epimers was 11.71 (11.1) at the peak and 1.14 (0.87) at 24 weeks, p = < 0.07. We conclude that, using a collection method which is reliable, non-stressful and repeatable at frequent intervals, new information on the evolution of steroid secretion and metabolism postpartum is emerging.
Taylor
N
N
Department of Clinical Chemistry, King's College School of Medicine, London, UK.
Sharma
S
S
Giffin
F
F
Naik
S
S
Greenough
A
A
D000305:Adrenal Cortex Hormones / Q000652:urine*; D000375:Aging; D002849:Chromatography, Gas; D005260:Female; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000652:urine; D007231:Infant, Newborn; D007234:Infant, Premature / Q000652:urine*; D007743:Labor, Obstetric / Q000502:physiology; D011247:Pregnancy; D013431:Sulfates / Q000652:urine
D000305:Adrenal Cortex Hormones; D013431:Sulfates; D006854:Hydrocortisone