Orthostatic intolerance in survivors of childhood cancer.
To compare the prevalence and severity of orthostatic intolerance in survivors of childhood cancer and in healthy controls, and to correlate results of self-reported measures of health status with orthostatic testing in survivors of childhood cancer. Thirty-nine survivors of childhood cancer and 56 controls were recruited for this study. Each cancer survivor completed standardised self-report measures and all participants underwent a standing test (5 min supine, 10 min of motionless standing leaning against a wall, followed by another 2 min supine). The main outcomes of the standing test were orthostatic tachycardia (OT), defined as a heart rate increase of at least 30 beats per minute (bpm) during standing, and neurally mediated hypotension (NMH), defined as a drop in systolic blood pressure of at least 25 mmHg. OT developed in 22/39 (56%) cancer survivors versus 17/56 (30%) controls (P=.01). Cancer survivors had a higher baseline and maximum standing heart rate (both P<.001) and a more rapid onset of significant OT (P=.005). No significant difference in scores on self-report measures was found between cancer survivors with or without OT. This study provides preliminary evidence of a higher rate of orthostatic intolerance in childhood cancer survivors. Further study is warranted to better define whether this is a modifiable risk factor for fatigue in this population, and how orthostatic intolerance interacts with other known risk factors for lowered quality of life.