Cardiac sympathetic burden reflects Parkinson disease burden, regardless of high or low orthostatic blood pressure changes

Reduced uptake of 123I-meta-iodobenzylguanidine (123I-MIBG) and orthostatic hypotension (OH) are independently associated with worse clinical outcomes of Parkinson’s disease (PD). However, their interactive influence on PD has not been studied. The role of 123I-MIBG myocardial uptake, as a biomarker of PD severity, was investigated, conditional on the mediating effects of OH. A total of 227 PD patients were enrolled. Their motor and nonmotor aspects were assessed with standardized tools. Global disease burden was estimated by averaging the scaled z-scores of the assessment tools. Every patient went through 123I-MIBG scan, and OH was evaluated with the head-up tilt-test. The mediating role of orthostatic blood pressure changes (ΔBP) on the association between cardiac sympathetic denervation and disease burden was investigated. Low heart-to-mediastinum (H/M) ratio with less than 1.78 was seen in 69.6% of the patient population, and 22.9% of patients had OH. Low H/M ratio was associated with OH, and these patients had worse disease burden than subjects with normal 123I-MIBG uptake (global composite z-score: normal 123I-MIBG vs. abnormal 123I-MIBG; −0.3 ± 0.5 vs. 0.1 ± 0.7; p < 0.001). The mediation models, controlled for age and disease duration, revealed that the delayed H/M ratio and global composite score were negatively associated, irrespective of orthostatic ΔBP. Adverse relationship between cardiac sympathetic denervation and disease burden was shown without any interference from orthostatic blood pressure fluctuations. This result suggested that extracranial cardiac markers might reflect disease burden, regardless of labile blood pressure influence.

Quantitative sensory testing and norepinephrine levels in REM sleep behaviour disorder – a clue to early peripheral autonomic and sensory dysfunction?

Introduction Studies have reported autonomic impairment in patients with idiopathic REM sleep behaviour disorder (iRBD), which is considered a prodromal stage of alpha-synucleinopathies. It is still debated whether central or peripheral pathologies are first manifestations of alpha-synucleinopathies. This study aimed to characterize autonomic and somatosensory function in iRBD patients. Methods This cross-sectional prospective case–control study included 17 iRBD patients (mean age 66.3 ± 9.2 years) and 16 healthy controls (HCs, 66.6 ± 11.3 years). Quantitative sensory testing, neurological and neuropsychological assessments, norepinephrine blood plasma levels, tilt table examination with orthostatic blood pressure, and heart rate variability were carried out. Longitudinal data of 10 iRBD patients, including neurological, neuropsychological, and tilt table examination, were assessed. Results iRBD patients more frequently presented with orthostatic dysfunction than HCs (70.6% vs. 6.3%, p < 0.0001). Supine norepinephrine plasma levels were normal, but lower in iRBD (249.59 ± 99.78 pg/ml iRBD, 354.13 ± 116.38 pg/ml HCs, p < 0.05). Quantitative sensory testing revealed impaired cold (CDT) and vibration detection thresholds (VDT) on the foot in iRBD (CDT foot iRBD − 1.24 ± 0.31, HCs − 9.89E-17 ± 0.25, VDT iRBD − 1.11 ± 0.47, HCs − 1.46E-16 ± 0.25, p < 0.05). Cold detection thresholds differed between the foot and hand among iRBD patients (foot − 1.24 ± 0.31, hand − 0.56 ± 0.25, p < 0.05). Longitudinal data revealed an increase in maximum systolic and diastolic orthostatic blood pressure changes and a decrease in the Valsalva ratio in the follow-up group (p < 0.05). Conclusion This study revealed autonomic dysfunction with somatosensory impairment, and decreased norepinephrine levels in iRBD, which may serve as a possible prodromal marker for developing alpha-synucleinopathy.

Abstract MP35: Association Of Orthostatic Blood Pressure Response With Incident Heart Failure: The Framingham Heart Study

Introduction: Orthostatic hypotension (OH) and hypertension (OHT) are associated with cardiovascular disease and mortality. The relation of OH and OHT with heart failure (HF) in the community is not well explored, particularly among the elderly and those with hypertension. Moreover, there remains a paucity of longitudinal data on the development of HF subtypes (HF with reduced ejection fraction [HFrEF] and HF with preserved ejection fraction [HFpEF]) in those with OH and OHT. Hypothesis: We hypothesized that OH and OHT are associated with a higher risk of HF. Methods: We evaluated 1914 Framingham Heart Study participants (mean age 72 years, 1159 women [61%]), with available orthostatic blood pressure (BP) measurements. OH was defined as a decrease and OHT as an increase of 20/10 mmHg in systolic/diastolic BP from supine to standing position, respectively. We used a categorical variable (OH, OHT, absence of OH and OHT [referent]). Using Cox proportional hazards regression, we related OH and OHT to risk of HF and its subtypes (HFrEF, HFpEF), compared to the referent group, adjusting for age, sex, body mass index, systolic BP, diastolic BP, hypertension treatment, smoking, and diabetes. Results: There were 275 participants with OH (181 women, 66%) and 411 with OHT (236 women, 57%). On median follow-up of 13 years, 492 developed HF (292 women, 59%). In multivariable-adjusted analyses, OH was associated with higher risk of HF (Hazards Ratio [HR] 1.47; 95% CI, 1.13-1.92; Figure ) compared to referent. Further, OH was associated with higher risk of HFrEF (HR 2.56; 95% CI, 1.46-4.48), but not HFpEF. OHT was not associated with incident HF. Conclusions: Assessment of orthostatic BP response in the elderly may identify future HF risk. Further studies are warranted to investigate mechanisms underlying the observed associations.

Orthostatic Blood Pressure Recovery Measured Using a Sphygmomanometer Is Not Associated with Physical Performance or Number of Falls in Geriatric Outpatients

<b><i>Background:</i></b> Orthostatic hypotension (OH) and impaired OH recovery derived from beat-to-beat blood pressure (BP) measurements are associated with detrimental clinical outcome, but the clinical relevance of OH recovery assessed using the widely available sphygmomanometer is still unclear. <b><i>Method:</i></b> 635 geriatric outpatients underwent comprehensive geriatric assessment, including orthostatic BP measurements using a sphygmomanometer, during supine rest and 1 and 3 min after standing up and assessment of physical performance (i.e., the timed up and go test and the Short Physical Performance Battery) and the number of falls in the past year. The association between BP recovery, defined as BP at 3 min minus BP at 1 min after standing up, with physical performance and falls was assessed using regression analyses, adjusting for age and sex, both in the entire cohort and after stratifying for the presence of OH at 1 min after standing up. <b><i>Results:</i></b> BP recovery was not associated with physical performance or number of falls, neither in the entire cohort, nor in subpopulations with or without OH. <b><i>Conclusion:</i></b> The clinical relevance of BP recovery between 1 and 3 min after standing up could not be demonstrated. The results suggest that sphygmomanometer measurements have an inadequate time resolution to record the clinically relevant dynamics of orthostatic BP recovery.