Fatigue in Parkinson’s Disease Associates with Lower Ambulatory Diastolic Blood Pressure

BACKGROUND/OBJECTIVE: Fatigue is a common debilitating symptom in Parkinson’s disease (PD) of unclear etiology. Hypotension and blood pressure variability are common in PD though their relationship to other non-motor symptoms is less well understood. METHODS: We conducted a cross-sectional study to explore differences in 24-hour ambulatory blood pressure measurements in PD subjects (n = 35) with and without fatigue. Subjects underwent hourly systolic (SBP) and diastolic (DBP) blood pressure testing in their home environment. The presence of fatigue was assessed using the Movement Disorders Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) part 1. We compared blood pressure measurements in fatigued vs. non-fatigued PD subjects, assessed over 4 epochs: overnight, morning, midday, and evening. RESULTS: PD subjects with symptoms of fatigue demonstrated lower mean DBP, compared to those without fatigue (67.8±4.8 mmHg vs. 75.6±9.4 t = 2.57, p = 0.014). These intergroup differences were most notable in the morning. The two groups did not differ in scoring on the Survey of Autonomic Symptoms or on an office-based blood assessment of SBP or DBP performed on the day of 24-hour monitor initiation. CONCLUSIONS: Fatigue in PD may be a clinical manifestation of low-grade systemic hypotension.