Endocrine Abstracts

It is unclear why GHD is associated with a reduced quality of life. Previous studies of GHD have shown impaired cardiovascular function and an increased cardiovascular mortality. We investigated whether the reduced quality of life is correlated with cardiac function and levels of cardiorespiratory fitness.

Eighteen adults (9 male) with severe, untreated, GHD were studied. Cardiac power and cardiorespiratory fitness were investigated using a new, non-invasive, maximal cardiopulmonary exercise test and compared with 164 healthy controls. Subjects also underwent transthoracic echocardiography and DEXA scan. Quality of life was assessed using the QoL-AGHDA score.

The AGHDA score was greater than 11/25 in all patients (mean 20). There was no difference in cardiac power, function and cardiorespiratory fitness between patients and controls (peak cardiac power±S.D. males: 4.76±0.7 W vs. 5.38±0.9, P=0.07; females: 3.97±1.2 W vs. 4.24±0.6, P=0.29). Echocardiography was normal. The AGHDA correlated with peak cardiac index (=cardiac output/body surface area, R=−0.50, P=0.03) but no other measure of cardiac performance.

The mean (±S.D.) IGF-1 (11.9±5.2 nmol/l) and IGF-1 Z score (−2.0±0.7) were low. There was a significant correlation between IGF-1 and VO₂Max/kg (R=0.78, P=0.001) and VO₂Max/Lean body mass (R=0.65, P=0.003). There was also a significant correlation between the IGF-1 Z score and VO₂Max/kg (R=0.52, P=0.02).

Subject’s quality of life was significantly reduced. Peak cardiac power and function and cardiorespiratory fitness were normal and did not correlate with the AGHDA score. There were significant correlations between IGF-1 and IGF-1 Z scores and measures of cardiorespiratory fitness and this may help clinicians develop a patient specific target for IGF-1 when treating patients with rhGH.