We have just received a result supporting the efficacy of 434 in orthostatic hypotension of MSA patients (only a trend in statistical analysis). In this new study, Prof. Claassen et al. found that PD patients also have severe hypotension after a meal, which is even more severe than in MSA. The difference is explained by the fact that in PD, the autonomic failure is in the periphery, but in MSA, it is more central.

I would not be surprised if 434 would help PD patients control hypotension reactions after a meal. Perhaps I should say that I would be more surprised if 434 did not help if it is ever tested. After this study, I am sure this issue will be tested one day. Prof Claassen is a "ATH434 man".


Beter to read the paper:https://link.springer.com/article/10.1007/s10286-025-01131-x

Clin Auton Res

. 2025 May 13.

doi: 10.1007/s10286-025-01131-x. Online ahead of print.

Peripheral autonomic failure is associated with more severe postprandial hypotension compared to central autonomic failure

Pouya E Mehr ¹, Pedro J Ortiz ¹, Kaitlyn R O'Rourke ², Tan Ding ³, Amber J Hackstadt ³, Surat Kulapatana ^{1 4 5}, André Diedrich ^{1 4}, Daniel O Claassen ², Italo Biaggioni ¹, Amanda C Peltier ^{1 2}, Cyndya A Shibao ⁶

Affiliations Expand

• PMID: 40360851

DOI: 10.1007/s10286-025-01131-x

Abstract

Purpose: Postprandial hypotension (PPH) defined as a decrease in systolic blood pressure of more than 20 mmHg within 2 h post meal is prevalent in patients with autonomic failure and is associated with negative cardiovascular outcomes. Previous studies reported peripheral autonomic failure with less residual sympathetic tone in Parkinson disease (PD). Therefore, we hypothesized that PPH is more severe in PD than in multiple system atrophy (MSA) with central autonomic failure.

Methods: Thirteen patients with PD and 13 patients with MSA were enrolled. Autonomic function testing and neurohormonal measurements were performed to assess autonomic failure and residual sympathetic activity. Subjects were fed a standard breakfast. Systolic and diastolic blood pressure and heart rate were monitored every 5 min from 30 min before to 120 min post meal. Postprandial hemodynamic changes were summarized using area under the curve (AUC). Differences between the groups were assessed with two-sample independent t test and linear regression.

Results: Patients with PD (69% male, 72 ± 9 years) had a significantly lower post-meal diastolic blood pressure (P = 0.003) and heart rate AUC (P = 0.007) than patients with MSA (62% male, 62 ± 8 years). After adjusting for age and supine systolic blood pressure, PD as diagnosis still had significant estimate effect for diastolic blood pressure AUC (P = 0.019). No significant difference was found in the mean systolic blood pressure AUC, but at 30 min post meal, systolic blood pressure decrease was significantly lower in PD (P = 0.016).

Conclusion: The PD group with peripheral autonomic failure exhibits more severe PPH than the MSA group. This highlights the need for tailored management for PPH in PD.