Related Experiment Videos
Pooled prolactin measurements in the evaluation of short children
D I Shulman1, C S Hu, A W Root
1Department of Pediatrics, University of South Florida College of Medicine, Tampa 33612.
Insights
Children with abnormal growth hormone (GH) responses showed higher daytime and 24-hour prolactin (PRL) levels. These elevated PRL levels in children may indicate hypothalamic-pituitary axis issues.
Area of Science:
- Pediatric Endocrinology
- Neuroendocrinology
Background:
- Prolactin (PRL) secretion exhibits diurnal variations and is influenced by growth hormone (GH) status.
- Evaluating GH status in children involves provocative testing and assessment of 24-hour GH concentrations.
Purpose of the Study:
- To investigate the relationship between GH status and PRL secretion patterns in children.
- To determine if altered GH secretion is associated with abnormal PRL levels in pediatric patients.
Main Methods:
- Serum PRL concentrations were measured in daytime, nighttime, and 24-hour pools in 63 children categorized by GH response.
- Children were grouped based on abnormal GH response, normal GH response with low 24-h GH, or normal GH response with adequate 24-h GH.
- PRL levels were assessed after provocative testing with insulin-TSH-LHRH and L-dopa administration.
Main Results:
- Children with abnormal GH responses had significantly higher daytime and 24-hour PRL concentrations compared to those with normal GH secretion.
- Nighttime PRL levels were higher than daytime levels in children with normal GH secretion but not in those with abnormal GH responses.
- Elevated or low 24-hour PRL concentrations were observed in a subset of children, with many linked to hypothalamic-pituitary axis insults.
Conclusions:
- Abnormal GH secretion in children is associated with dysregulated PRL secretion, particularly elevated daytime levels.
- Altered PRL secretion patterns may serve as an indicator of underlying hypothalamic-pituitary dysfunction in children evaluated for GH status.
- Further investigation into the link between GH and PRL regulation is warranted in pediatric populations.
Abstract:
PRL secretion was determined in 63 children undergoing evaluation of GH status. Children were assigned to 1 of 3 groups based on GH studies: group 1, those with abnormal GH responses to provocative testing (n = 23); group 2, children with normal GH responses to provocative testing and mean 24-h GH concentrations below 2.5 micrograms/L (n = 14); or group 3, those with normal stimulated GH secretion and mean 24-h GH concentrations of 2.5 micrograms/L or more (n = 26). Serum PRL concentrations were measured in daytime (0800-1600 h), nighttime (2200-0600 h), and 24-h pools of serum specimens obtained every 20 min over a 24-h period. Mean (+/- SD) daytime (17.5 +/- 14.3 micrograms/L) and 24-h (19.2 +/- 13.0 micrograms/L) pool PRL concentrations were significantly higher in group 1 than in group 3 (daytime, 6.7 +/- 2.3; 24 h, 10.2 +/- 2.5 micrograms/L; P less than 0.01). Mean nighttime pool PRL concentrations did not differ among groups. Mean nighttime pool PRL values were significantly higher (P less than 0.01) than daytime pool values in group 3 (nighttime pool, 13.6 +/- 3.6 micrograms/L; night to day ratio, 2.2 +/- 1.0) and group 2 (16.8 +/- 9.0 micrograms/L; night to day ratio, 2.5 +/- 1.5), but not within group 1 (21.4 +/- 13.5 micrograms/L; night to day ratio, 1.4 +/- 0.5). The mean peak and increment in PRL concentrations after an iv bolus of insulin-TSH-LHRH were not different among groups. The mean decrement in serum PRL level after L-dopa ingestion was greater in group 1 than in group 3 (P less than 0.05). Two children in group 2 and 10 in group 1 had significantly elevated daytime pool PRL concentrations (greater than 11.3 micrograms/L; 2 SD above the mean value for group 3). Two additional children in group 2 and 2 in group 1 had elevated 24-h (greater than 15.2 micrograms/L) pool PRL concentrations. One child in group 2 and 3 in group 1 had low 24-h PRL concentrations (less than 5.2 micrograms/L; less than 2 SD below the mean of group 3). Fourteen of 20 children with elevated daytime and/or 24-h pool PRL levels or low 24-h pool PRL values had structural or radiation-associated insults to the hypothalamic-pituitary axis evident in the history or with brain-imaging techniques; 1 had microphallus with panhypopituitarism and 5 children had no structural abnormalities.(ABSTRACT TRUNCATED AT 400 WORDS)