Reduced cardiac functional reserve and quality of life in adults with GH deficiency

Area of Science:

• Cardiology
• Endocrinology
• Exercise Physiology

Background:

• Severe Growth Hormone Deficiency (GHD) is linked to reduced quality of life and cardiac alterations.
• The impact of GHD on cardiac reserve during peak exercise remains largely unquantified.
• This study investigates if impaired cardiac reserve in GHD patients contributes to their diminished quality of life.

Purpose of the Study:

• To test the hypothesis that severe GHD patients have reduced cardiac reserve function compared to healthy controls.
• To assess if this reduced cardiac reserve explains, in part, their reduced quality of life.

Main Methods:

• Eighteen severe GHD patients and 18 matched healthy controls underwent maximal cardiopulmonary exercise testing.
• Noninvasive hemodynamic measurements assessed peak cardiac power and cardiorespiratory fitness.
• The Assessment of GHD in Adults (AGHDA) score was used to evaluate GHD severity.

Main Results:

• GHD patients showed a 15% reduction in peak cardiac power during maximal exercise compared to controls (4.4 ± 1.0 W vs. 5.2 ± 1.0 W, P = 0.02).
• Patients exhibited significantly lower cardiac chronotropic reserve (peak heart rate 154 ± 21/min vs. 174 ± 11/min, P = 0.001) and impaired pressure-generating capacity (systolic blood pressure 160 ± 25 mmHg vs. 200 ± 15 mmHg, P < 0.0001).
• No correlation was found between cardiac function measures and the AGHDA score.

Conclusions:

• Severe GHD is associated with significantly impaired cardiac functional reserve, characterized by chronotropic incompetence and reduced pressure-generating capacity.
• Despite impaired cardiac function, this study found no correlation with quality of life as assessed by the AGHDA score.
• Noninvasive assessment of functional cardiac pumping capacity reveals novel insights into GHD pathophysiology.