A 24-hour comparison of serum growth hormone concentrations in patients with heart failure versus healthy controls.

STUDY OBJECTIVE: To compare endogenous serum growth hormone concentrations over a 24-hour period in patients with chronic heart failure (CHF) and matched controls. DESIGN: Prospective, 24-hour, endogenous concentration comparison. SETTING: Hospital research center. PATIENTS: Eight evaluable patients with nonischemic dilated cardiomyopathy and 10 healthy control subjects, matched for age and sex. INTERVENTION: Over a 24-hour period, blood was drawn from the study participants every 20 minutes for determination of growth hormone. MEASUREMENTS AND MAIN RESULTS: For each patient, the area under the concentration-time curve from time 0-24 hours (AUC0-24), maximum concentration (Cmax), and minimum concentration (Cnadir) of growth hormone were determined. The AUC0-24 and Cmax were 74% (p < 0.05) and 62% (p < 0.05) lower in patients with CHF than in controls, respectively. The Cnadir for all participants was 0 microg/L. Variability in growth hormone concentrations over the 24 hours was considerable for all study participants. CONCLUSIONS: Growth hormone concentrations are suppressed over a 24-hour period in patients with CHF versus healthy controls. Variability in levels throughout the day suggests that a single point evaluation cannot be used to determine deficiency or abundance of growth hormone.

Duke Scholars

Author Anita Kelsey Medicine, Cardiology