Blood pressure circadian rhythm alterations in alpha-synucleinopathies

Introduction: We sought to analyze the blood pressure (BP) circadian rhythm in Parkinson's disease (PD), multiple system atrophy (MSA), and pure autonomic failure (PAF) and to evaluate the effect of vasoactive and dopaminergic medications on BP fluctuations during activities of daily living. Methods: We analyzed data from patients with PD (n=72), MSA (n=18), and PAF (n=17) evaluated with 24-h ambulatory BP monitoring (ABPM) at our Center between 1996 and 2015. Comparisons between groups were performed according to (a) clinical diagnosis and (b) pharmacological treatment. ABPM parameters included 24-h BP variability, BP load, nocturnal dipping, and awakening hypotension. Results: The average BP was 12114/72 +/- 8 mmHg during daytime and 133 +/- 20/76 +/- 13 mmHg during nighttime (p<0.01), with BP load of 24 +/- 22/15 +/- 16% (daytime) vs. 61 +/- 36/52 +/- 36% (nighttime) (p<0.01). In-office BP measurements were consistent with OH in 95 patients (89%) and SH in 63 (59%). ABPM demonstrated increased BP variability in 67 patients (63%), awakening hypotension in 63 (59%), "reverse dipping" in 85 (79.4%), "reduced dipping" in 13 (12.1%), and "normal dipping" in 9 (8.4%). No differences were observed between PD, MSA, and PAF, but a sub-analysis of PD patients revealed two distinct patterns of BP alterations. No significant differences were observed in relation to the use of vasoactive or dopaminergic medications. Conclusion: Regardless of the neurological diagnosis and pharmacological treatment, patients with alpha-synucleinopathies showed a BP circadian rhythm characterized by increased BP variability, reverse dipping, increased BP load, and awakening hypotension.