In view of increased SNS tone in OSA does the comorbidity of OSA interfere with the assessment of metanephrines and catecholamines when screening for pheochromocytoma?
Yes. OSA results in an appropriate release of catecholamines in response to physiologic stress or disease, just as myocardial infarctions, cerebral vascular accidents, and acute heart failure are associated with appropriate acute catecholamine increases. If a 24-hour urinary collection is performed in the setting of undiagnosed or poorly treated OSA, it would likely contain elevated metanephrine and catecholamine levels. This may falsely suggest a diagnosis of pheochromocytoma.