[Growth hormone secretion in heart failure]

Area of Science:

• Endocrinology
• Cardiology
• Physiology

Background:

• Growth hormone (GH) is a pituitary hormone crucial for growth and anabolic processes.
• GH and Insulin-like Growth Factor-I (IGF-I) receptors are present in cardiac myocytes, suggesting a role in cardiovascular function.
• Pituitary gland may compensate for endocrine changes in heart failure, with nocturnal GH levels correlating to disease severity.

Purpose of the Study:

• To investigate the relationship between spontaneous GH secretion and heart failure.
• To evaluate the effects of GH infusion on patients with heart failure.
• To identify patient subgroups that may benefit from GH treatment based on their endocrine status.

Main Methods:

• Assessed spontaneous GH and IGF-I secretion in heart failure patients.
• Administered 24-hour GH infusion to heart failure patients.
• Correlated cardiovascular responses to GH infusion with basal endocrine profiles.

Main Results:

• Heart failure stage correlated with nocturnal GH levels.
• GH infusion increased GH concentration fivefold and basal IGF-I by 50%.
• Patients with low basal IGF-I and high basal GH showed the poorest response to GH infusion, indicating potential GH resistance.

Conclusions:

• Heart failure patients exhibit altered GH secretion patterns, including potential GH resistance or reduced GH/IGF-I axis activity.
• Basal endocrine status, particularly GH resistance, influences cardiovascular response to GH administration.
• Pre-treatment evaluation of endocrine status is crucial for optimizing GH therapy in heart failure patients.