Serum concentrations of adrenal steroids and their precursors as a measure of maturity of adrenocortical function in very premature newborns.
BACKGROUND
Relative adrenocortical insufficiency is often seen in sick premature newborns. As the human fetal adrenal cortex does not express the 3β-hydroxysteroid dehydrogenase (3β-HSD) enzyme before about 23 weeks of gestation, we hypothesized that this enzymatic step may be rate limiting in cortisol synthesis in premature infants of less than 28 weeks postmenstrual age at birth.


METHODS
We measured cord, first day (D0) and median fourth day (D4) serum 17-OH-pregnenolone (17-OHPreg), 17-OH-progesterone (17-OHProg), 11-deoxycortisol, cortisol (F) and dehydroepiandrosterone sulphate concentrations and calculated the substrate/product ratios in 67 infants with gestational age 23.6-33.1 weeks.


RESULTS
The mean 17-OHPreg/17-OHProg ratio as a marker of 3β-HSD activity did not differ between the gestational age groups (gestational age <28 vs. ≥28 weeks: 0.40 vs. 0.48, p = 0.52 for cord, 3.1 vs. 2.4, p = 0.25 for D0, and 1.6 vs. 1.9, p = 0.62 for D4). In addition, the 17-OHPreg/17-OHProg ratio did not differ between the infants in the lowest F tertile compared to those in the highest F tertile group, and the serum 17-OHPreg and 17-OHProg concentrations were parallel with the respective F concentrations.


CONCLUSIONS
We did not find evidence of significant immaturity in adrenal 3β-HSD activity in preterm infants between 24 and 28 weeks of gestation.
Nykänen
Päivi
P
Department of Pediatrics, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
Heinonen
Kirsti
K
Riepe
Felix G
FG
Sippell
Wolfgang G
WG
Voutilainen
Raimo
R
D006907:17-alpha-Hydroxypregnenolone / Q000097:blood; D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000302:Adrenal Cortex / Q000254:growth & development* / Q000502:physiology*; D000304:Adrenal Cortex Function Tests; D000305:Adrenal Cortex Hormones / Q000097:blood*; D000328:Adult; D001034:Apgar Score; D001724:Birth Weight; D002821:Chorioamnionitis / Q000473:pathology; D015331:Cohort Studies; D003350:Cortodoxone / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000096:biosynthesis; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D011225:Pre-Eclampsia / Q000473:pathology; D011247:Pregnancy; D011446:Prospective Studies
D000305:Adrenal Cortex Hormones; D006907:17-alpha-Hydroxypregnenolone; D019314:Dehydroepiandrosterone Sulfate; D019326:17-alpha-Hydroxyprogesterone; D015096:3-Hydroxysteroid Dehydrogenases; D003350:Cortodoxone; D006854:Hydrocortisone