Related Experiment Videos
Leptin, cortisol, and GH secretion interactions in short normal prepubertal children
L Ghizzoni1, G Mastorakos, M E Street
1Department of Pediatrics, University of Parma, 43100 Parma, Italy. lucia..ghizzoni@unipr.it
Insights
This study reveals complex interactions between leptin, cortisol, and growth hormone (GH) in children. Cortisol appears to inhibit leptin secretion, while leptin may stimulate the hypothalamic-pituitary-adrenal axis, and GH positively influences leptin release.
Area of Science:
- Endocrinology
- Human Physiology
- Chronobiology
Background:
- The precise hormonal regulation of the ob gene and leptin secretion in humans remains incompletely understood.
- Investigating the interplay between leptin, cortisol, and growth hormone (GH) is crucial for understanding metabolic and endocrine functions.
Purpose of the Study:
- To elucidate the temporal interactions among spontaneous 24-hour secretions of leptin, cortisol, and GH in prepubertal children.
- To analyze the cross-correlations between these hormones to infer regulatory pathways.
Main Methods:
- Analysis and time-cross-correlation of spontaneous 24-hour hormone secretion profiles.
- Study population: 12 short, normal, prepubertal children (6 males, 6 females).
Main Results:
- Leptin and cortisol exhibited both negative and positive correlations, suggesting bidirectional influences possibly mediated by the hypothalamic-pituitary-adrenal (HPA) axis.
- Cortisol led leptin secretion (inhibitory effect), while leptin led cortisol secretion (potential stimulatory effect on HPA axis).
- A strong positive correlation was observed between GH and leptin, with GH preceding leptin, indicating a potential direct GH effect on leptin release from adipocytes.
Conclusions:
- The HPA axis likely exerts a predominant inhibitory effect on leptin secretion, whereas leptin may positively modulate the HPA axis.
- The relationship between GH and leptin appears direct, with GH potentially stimulating leptin secretion.
- Further research is required to validate these findings using diverse experimental approaches.
Abstract:
The hormonal regulation of the ob gene and leptin secretion in humans is still unclear. To investigate the interactions among leptin, cortisol, and GH, we analyzed and time-cross-correlated their spontaneous 24-h secretion in 12 short normal prepubertal children of both sexes (6 females and 6 males). Time-cross-correlation analyses demonstrated that leptin and cortisol were correlated in both a negative and positive fashion. The negative correlation, with cortisol leading leptin by 4 and 3 h for boys and girls, respectively, might reflect the stimulatory effect of CRH on the sympathetic system, which inhibits leptin secretion; the positive correlation, with leptin leading cortisol by 6 and 5 h for boys and girls, respectively, might reflect a direct effect of leptin on CRH secretion in the hypophyseal portal system. Time-cross-correlation analyses also showed a strong positive correlation between GH and leptin concentrations, with GH leading leptin by 5 and 2 h for boys and girls, respectively, suggesting a possible direct leptin-releasing effect of GH on adipocytes. We conclude that cross-correlation analyses of 24-h hormone secretions under baseline physiological conditions suggest that the hypothalamic-pituitary-adrenal axis might have a prevailing inhibitory effect on leptin secretion, whereas leptin might exert a positive effect on the hypothalamic-pituitary-adrenal axis. The relation between GH and leptin could be a direct one and characterized prevalently by a positive effect of GH on leptin secretion. Further investigations using different experimental systems are needed to ascertain the validity of these mathematically educed conclusions.