Endocrine Abstracts

Introduction: Orthostatic hypertension (OHT) is a phenomenon which may represent increased cardiovascular risk and is less well recognized compared to orthostatic hypotension.

Case: A 65 year old gentleman presented with symptoms of lethargy and episodic shaking. He has a history of treated prostate cancer and was not on any regular medications. He noticed consistently elevated blood pressure on standing during home monitoring. His lying BP was 142/82 and standing BP was 184/114 in clinic and other systems exam was unremarkable. Plasma metanephrines and a Head up tilt test were organized, results awaited. As he had consistent and significant increase in postural BP, he was commenced on Doxazosin at night.

Discussion: OHT has been variably defined in literature. Although usually asymptomatic, non-vertiginous dizziness can be a presenting symptom. OHT was prevalent in 28% (in contrast to 16% for orthostatic hypotension) in the PARTAGE study of elderly institutionalized population but previous reports in community individuals have varied between 1 and 11%. Alpha-adrenergic sympathetic hyperactivity has been the suggested mechanism. Patients with OHT have been noted to have elevated norepinephrine levels and peripheral vascular sensitivity. Whilst OHT has been considered to be a marker of cardiovascular frailty and has been associated with masked hypertension, consistent evidence linking OHT and adverse outcomes is lacking. The Japan Morning Surge 1 Study showed that Doxazosin suppressed orthostatic BP increase and reduced urine albumin excretion.

Conclusion: Assessing people for postural blood pressure may identify this group of individuals with potentially increased CV risk and allow early intervention. However, the evidence for specific treatment of OHT is still lacking.