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Dopamine suppresses pituitary function in infants and children
G Van den Berghe1, F de Zegher, P Lauwers
1Department of Intensive Care Medicine, University Hospital Gasthuisberg, Leuven, Belgium.
Insights
Dopamine infusion in critically ill infants and children suppresses pituitary hormone secretion, potentially causing partial hypopituitarism and euthyroid sick syndrome. Withdrawal leads to rebound hormone releases.
Area of Science:
- Pediatric Intensive Care Medicine
- Endocrinology
- Pharmacology
Background:
- Dopamine is a critical inotropic and vasoactive agent in pediatric intensive care.
- The pituitary gland is vital for growth, metabolism, and maturation in children.
- The effects of dopamine on pituitary-thyroid axis in critically ill children are not fully understood.
Purpose of the Study:
- To evaluate the impact of dopamine infusion on prolactin, growth hormone, and thyrotropin secretion.
- To assess dopamine's effect on the thyroid axis in critically ill infants and children.
- To investigate hormone dynamics following dopamine withdrawal.
Main Methods:
- Prospective, randomized, controlled, open-label clinical study.
- Critically ill infants and children recovering from cardiovascular surgery were studied.
- Hormone levels (prolactin, GH, IGF-1, TSH, T4, T3, reverse T3) were measured dynamically before and after dopamine withdrawal.
Main Results:
- Dopamine suppressed prolactin, growth hormone, and thyrotropin in newborns, with rebound after withdrawal.
- In children, dopamine suppressed prolactin and thyrotropin, but not growth hormone, with rebound effects.
- Thyroid hormone levels (T3, T4) and T3/reverse T3 ratio were altered, suggesting euthyroid sick syndrome, particularly in children.
Conclusions:
- Dopamine infusion may induce or worsen partial hypopituitarism in critically ill infants and children.
- Dopamine administration is associated with the development or exacerbation of euthyroid sick syndrome.
- These findings highlight potential endocrine complications of dopamine therapy in pediatric critical care.
Objectives:
Dopamine, a natural catecholamine with hypophysiotropic properties, is used as a first choice drug for inotropic and vasoactive support in pediatric intensive care. In infants and children, the pituitary gland plays a crucial role as a regulator of growth, metabolism, maturation and, possibly, immune function. We evaluated the effect of dopamine infusion (5 micrograms/kg/min i.v.) on the dynamics of prolactin, growth hormone, and thyrotropin secretion and on the thyroid axis in critically ill infants and children.
Design:
Prospective, randomized, controlled, open-labeled, clinical study.
Setting:
Intensive care unit of a university hospital over a 9-month period.
Patients And Methods:
The study population consisted of infants and children recovering from cardiovascular surgery. The group was stratified into two age groups (infants aged 12 to 90 days [n = 18] and children aged 0.3 to 6.7 yrs [n = 15]) and was studied dynamically (blood sampling every 20 mins for 3 hrs) on two consecutive days, after randomization for dopamine withdrawal on the first or the second day. Serum prolactin, growth hormone, insulin-like growth factor-1, thyrotropin, thyroxine (T4), triiodothyronine (T3), and reverse triiodothyronine (reverse T3) concentrations were measured.
Measurements And Main Results:
In the newborns, dopamine was found to suppress prolactin, growth hormone, and thyrotropin secretion consistently, rebound releases starting within 20 mins after dopamine withdrawal. One day later, prolactin concentrations were ten times higher, pulsatile growth hormone secretion was augmented, thyrotropin was unchanged, but T3 was increased by 30% and the T3/reverse T3 ratio was inverted. In the children, dopamine suppressed prolactin and thyrotropin (but not growth hormone) secretion, rebound releases starting within 20 mins after dopamine withdrawal. One day later, prolactin concentrations were at least twice as high, thyrotropin was increased ten-fold, T4 was augmented by 14%, T3 by 30% and the T3/reverse T3 ratio had doubled. Neither in newborns nor in children did dopamine withdrawal appear to affect the low serum insulin-like growth factor-1 concentrations.
Conclusions:
The data indicate that dopamine infusion induces or aggravates partial hypopituitarism and the euthyroid sick syndrome in critically ill infants and children.