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7
result(s) for
"Pilz, Niklas"
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Pulse Wave Velocity: Methodology, Clinical Applications, and Interplay with Heart Rate Variability
by
Pilz, Niklas
,
Tomas Lucca Bothe
,
Patzak, Andreas
in
Doppler effect
,
Magnetic resonance imaging
,
Sensors
2024
Pulse wave velocity (PWV) has been established as a promising biomarker in cardiovascular diagnostics, providing deep insights into vascular health and cardiovascular risk. Defined as the velocity at which the mechanical wave propagates along the arterial wall, PWV represents a useful surrogate marker for arterial vessel stiffness. PWV has garnered clinical attention, particularly in monitoring patients suffering from vascular diseases such as hypertension and diabetes mellitus. Its utility extends to preventive cardiology, aiding in identifying and stratifying cardiovascular risk. Despite the development of various measurement techniques, direct or indirect tonometry, Doppler ultrasound, oscillometric analysis, and magnetic resonance imaging (MRI), methodological variability and lack of standardization lead to inconsistencies in PWV assessment. In addition, PWV can be estimated through surrogate parameters, such as pulse arrival or pulse transit times, although this heterogeneity limits standardization and, therefore, its clinical use. Furthermore, confounding factors, such as variations in sympathetic tone, strongly influence PWV readings, thereby necessitating careful control during assessments. The bidirectional relationship between heart rate variability (HRV) and PWV underscores the interplay between cardiac autonomic function and vascular health, suggesting that alterations in one could directly influence the other. Future research should prioritize the standardization and increase comparability of PWV measurement techniques and explore the complex physiological variables influencing PWV. Integrating multiple physiological parameters such as PWV and HRV into algorithms based on artificial intelligence holds immense promise for advancing personalized vascular health assessments and cardiovascular care.
Journal Article
The B-Score is a novel metric for measuring the true performance of blood pressure estimation models
2022
We aimed to develop and test a novel metric for the relative performance of blood pressure estimation systems (B-Score). The B-Score sets absolute blood pressure estimation model performance in contrast to the dataset the model is tested upon. We calculate the B-Score based on inter- and intrapersonal variabilities within the dataset. To test the B-Score for reliable results and desired properties, we designed generic datasets with differing inter- and intrapersonal blood pressure variability. We then tested the B-Score’s real-world functionality with a small, published dataset and the largest available blood pressure dataset (MIMIC IV). The B-Score demonstrated reliable and desired properties. The real-world test provided allowed the direct comparison of different datasets and revealed insights hidden from absolute performance measures. The B-Score is a functional, novel, and easy to interpret measure of relative blood pressure estimation system performance. It is easily calculated for any dataset and enables the direct comparison of various systems tested on different datasets. We created a metric for direct blood pressure estimation system performance. The B-Score allows researchers to detect promising trends quickly and reliably in the scientific literature. It further allows researchers and engineers to quickly assess and compare performances of various systems and algorithms, even when tested on different datasets.
Journal Article
Blood pressure measurement and nocturnal dipping patterns are heavily affected by body posture through changes in hydrostatic pressure between the arm and the heart
2025
Nocturnal blood pressure (BP) shows the highest predictive power for cardiovascular events. However, there is a poor reproducibility of personalized dipping patterns in single individuals. We hypothesize that changes in body position during sleep cause variations in hydrostatic pressure,leading to incorrect BP values and dipping classifications. 26 subjects aged 18–30 years, as well as 25 participants aged 50 years and older underwent ambulatory BP measurements on the left arm, as well as determination of the hydrostatic pressure difference between the cuff and heart level during BP measurement. We observed that the BP measurement cuff was above the heart level (negative hydrostatic pressure) mostly through the night. Laying on the right side revealed the largest hydrostatic pressure difference and maximum incorrect BP measurement, with a mean of –9.61 mmHg during sleep. Correcting for hydrostatic pressure led to reclassification of nocturnal hypertension in 14 subjects (27.5%). Dipping patterns changed in 19 participants (37.3%). In total, 25 subjects (49.0%) changed either their nocturnal hypertension and/or their dipping classification. Our findings underscore the importance of accounting for hydrostatic pressure in ambulatory BP monitoring. Changes in body posture during sleep provide a plausible reason for the variability seen in nocturnal dipping patterns. Further research should focus on incorporating hydrostatic pressure compensation mechanisms in 24-h BP measurement. Limiting the noticeable effect of hydrostatic pressure differences could greatly improve hypertension diagnosis, classification, and treatment monitoring.
Journal Article
Impact of peripheral skin cooling on neuroendocrine leukocytic and hematological reactions during Hypergravity
2025
Optimal neuroendocrine responses are essential during hypergravity (+Gz) exposure. Peripheral skin cooling (PSC) may enhance neuroendocrine function, potentially improving +Gz resiliency and influencing leukocyte and hematologic factors. This study investigated whether PSC augments the cumulative +Gz stress index (CGSI) and shifts it toward noradrenergic dependency. Eighteen men underwent a graded +Gz profile in a crossover design, with PSC applied using Arctic Sun cooling pads. Neuroendocrine and blood profiles were assessed pre- and post-+Gz. CGSI did not differ between groups, but serum osmolality increased only in PSC (
p
= 0.03). In PSC, CGSI correlated with norepinephrine (
p
< 0.01,
r
= 0.71) and other markers, suggesting enhanced norepinephrine responsiveness despite similar serum levels. This response may be cardio-protective for space missions and ICU patients. Additionally, baseline serum metanephrine emerged as a potential marker for +Gz resilience, with PSC showing potential leukocytic and hematologic involvement in CGSI.
Journal Article
Assessment of Nocturnal Blood Pressure: Importance of Determining the Time in Bed—A Pilot Study
by
Pilz, Niklas
,
Patzak, Andreas
,
Hofmann, Elisabeth
in
Blood pressure
,
Cardiovascular diseases
,
Datasets
2024
Objectives: Nocturnal blood pressure (BP) monitoring is essential for evaluating cardiovascular risk and guiding treatment decisions. However, the standardized narrow-fixed nighttime period between 10 p.m. and 6 a.m. may not accurately reflect individual sleep schedules. This pilot study aimed to investigate the comparability between the standardized nighttime period and actual time in bed (TIB) regarding BP assessment. Further, our goal was to evaluate the clinical relevance of the observed BP differences. Methods: A total of 30 participants underwent 24 h ambulatory blood pressure monitoring (ABPM). Patient-specific TIB was precisely assessed through an accelerometer and a position sensor from the SOMNOtouch NIBP™ (SOMNOmedics GmbH, Randersacker, Germany). We analysed the effect of considering individual TIB as nighttime instead of the conventional narrow-fixed interval on the resulting nocturnal BP levels and dipping patterns. Results: We observed differences in both systolic and diastolic BP between the standardized nighttime period and the TIB. Furthermore, a notable percentage of patients (27%) changed their dipping pattern classification as a function of the nighttime definition adopted. We found strong correlations between the start (r = 0.75, p < 0.01), as well as the duration (r = −0.42, p = 0.02) of TIB and the changes in dipping pattern classification. Conclusions: Definition of nocturnal period based on the individual TIB leads to clinically relevant changes of nocturnal BP and dipping pattern classifications. TIB is easily detected using a body position sensor and accelerometer. This approach may thus improve the accuracy of cardiovascular risk evaluation and enhance treatment strategies.
Journal Article
The personality traits activity, self-reproach, and negative affect jointly predict clinical recurrence, depressive symptoms, and low quality of life in inflammatory bowel disease patients
by
Pilz, Julia Beatrice
,
Lang, Brian Matthew
,
Belli, Dominique
in
Cohort analysis
,
Disease
,
Emotions
2022
BackgroundThe bidirectional “gut-brain axis” has been implicated in the pathogenesis of inflammatory bowel diseases (IBD). While the influence of stress and depressive symptoms on IBD is well-characterized, the role of personality remains insufficiently investigated.MethodsPersonality was assessed in 1154 Swiss IBD cohort study (SIBDCS) patients via the NEO-Five-Factor Inventory (NEO-FFI) as well as in 2600 participants of the population-based CoLaus¦PsyCoLaus cohort study (NEO-FFI-revised). The NEO-FFI subcomponents activity, self-reproach and negative affect were associated with higher IBD disease activity and were combined to a NEO-FFI risk score. This risk score was validated and its effect on clinical IBD course and psychological endpoints was analysed in time-to-event and cumulative incidence analyses.ResultsIn time-to-event analyses, a high NEO-FFI risk score was predictive for the clinical endpoints of new extraintestinal manifestation [EIM, adjusted hazard ratio (aHR) = 1.64, corrected p value (q) = 0.036] and two established composite flare endpoints (aHR = 1.53–1.63, q = 0.003–0.006) as well as for the psychological endpoints depressive symptoms (aHR = 7.06, q < 0.001) and low quality of life (aHR = 3.06, q < 0.001). Furthermore, cumulative incidence analyses showed that patients at high NEO-FFI risk experienced significantly more episodes of active disease, new EIMs, one of the flare endpoints, depressive episodes and low disease-related quality of life. Personalities of IBD patients showed only minor differences from the general population sample (Pearson’s r = 0.03–0.14).ConclusionsPersonality assessed by the NEO-FFI contained considerable predictive power for disease recurrence, depressive symptoms and low quality of life in IBD patients. Nevertheless, the personalities of IBD patients did not substantially differ from the general population.
Journal Article
Abdominal pain in patients with inflammatory bowel disease: association with single-nucleotide polymorphisms prevalent in irritable bowel syndrome and clinical management
by
Heinrich, Henriette
,
Misselwitz, Benjamin
,
Rogler, Gerhard
in
Abdomen
,
Abdominal pain
,
Abdominal Pain - genetics
2021
Background
Abdominal pain is a frequent symptom in patients with inflammatory bowel disease (IBD) including Crohn’s disease (CD) and ulcerative colitis (UC). Pain can result from ongoing inflammation or functional disorders imitating irritable bowel syndrome (IBS). Several single-nucleotide polymorphisms (SNPs) have been associated with IBS. However, the impact of IBS genetics on the clinical course of IBD, especially pain levels of patients remains unclear.
Methods
Data of 857 UC and 1206 CD patients from the Swiss IBD Cohort Study were analysed. We tested the association of the maximum of the abdominal pain item of disease activity indices in UC and CD over the study period with 16 IBS-associated SNPs, using multivariate ANOVA models.
Results
In UC patients, the SNPs rs1042713 (located on the ADRB2 gene) and rs4663866 (close to the HES6 gene) were associated with higher abdominal pain levels (
P
= 0.044;
P
= 0.037, respectively). Abdominal pain was not associated with any markers of patient management in a model adjusted for confounders. In CD patients, higher levels of abdominal pain correlated with the number of physician contacts (
P
< 10
–15
), examinations (
P
< 10
–12
), medical therapies (
P
= 0.023) and weeks of hospitalisation (
P
= 0.0013) in a multivariate model.
Conclusions
We detected an association between maximal abdominal pain in UC patients and two IBS-associated SNPs. Abdominal pain levels had a pronounced impact on diagnostic and therapeutic procedures in CD but not in UC patients.
Journal Article