Orthostatic hypotension in Parkinson's disease: Does it matter if asymptomatic?

INTRODUCTION: Orthostatic hypotension (OH) may frequently be asymptomatic in patients with Parkinson's disease (PD). However, the relationship between symptomatic/asymptomatic status and functional disability remains unclear. METHODS: Using orthostatic blood pressure (BP) measurements and the Orthostatic Hypotension Symptom Assessment (OHSA) questionnaire, 121 consecutive PD patients without history of chronic hypertension and not taking alpha-adrenergic antagonists for bladder disorders were classified according to (1) OH symptomatic status, based on presence/absence of orthostatic symptoms (symptomatic OH: OHSA item 1 ≥ 1), and (2) OH severity, based on the magnitude of BP fall on the lying-to-standing test: OH- (<20/10 mmHg); moderate OH+ (≥20/10 mmHg but < 30/15 mmHg); and severe OH+ (≥30/15 mmHg). The primary endpoints were the activities of daily living/instrumental activities of daily living (ADL/iADL) and the Ambulatory Capacity Measure (ACM). Secondary endpoints included PD quality of life (PDQ-8) and prevalence of falls. RESULTS: The overall prevalence of OH+ was 30.6% (37/121 patients), with 62.2% symptomatic (23/37) and 37.8% asymptomatic (14/37). Symptomatic and asymptomatic OH + patients had similar impairments in ADL/iADL and ACM, significantly worse than OH- (p ≤ 0.035). There was a trend for worse ADL/iADL and ACM scores in severe OH + compared to moderate OH+, but both were worse than OH- (p ≤ 0.048). Symptomatic and asymptomatic OH + showed similar impairment in PDQ-8 and higher prevalence of falls compared to OH-. CONCLUSIONS: Asymptomatic OH+ was associated with similar impairments in ADL/iADL and ACM than symptomatic OH+. These findings support screening for OH in PD patients regardless of postural lightheadedness.