@phdthesis{Blaser2024, author = {Blaser, Berenike Lisa}, title = {Premenstrual symptoms as a function of altered central autonomous nervous activity}, doi = {10.25932/publishup-64597}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-645970}, school = {Universit{\"a}t Potsdam}, pages = {XII, 265}, year = {2024}, abstract = {The experience of premenstrual syndrome (PMS) affects up to 90\% of individuals with an active menstrual cycle and involves a spectrum of aversive physiological and psychological symptoms in the days leading up to menstruation (Tschudin et al., 2010). Despite its high prevalence, the precise origins of PMS remain elusive, with influences ranging from hormonal fluctuations to cognitive, social, and cultural factors (Hunter, 2007; Matsumoto et al., 2013). Biologically, hormonal fluctuations, particularly in gonadal steroids, are commonly believed to be implicated in PMS, with the central factor being varying susceptibilities to the fluctuations between individuals and cycles (Rapkin \& Akopians, 2012). Allopregnanolone (ALLO), a neuroactive steroid and progesterone metabolite, has emerged as a potential link to PMS symptoms (Hantsoo \& Epperson, 2020). ALLO is a positive allosteric modulator of the GABAA receptor, influencing inhibitory communication (Rupprecht, 2003; Andr{\´e}en et al., 2006). Different susceptibility to ALLO fluctuations throughout the cycle may lead to reduced GABAergic signal transmission during the luteal phase of the menstrual cycle. The GABAergic system's broad influence leads to a number of affected physiological systems, including a consistent reduction in vagally mediated heart rate variability (vmHRV) during the luteal phase (Schmalenberger et al., 2019). This reduction in vmHRV is more pronounced in individuals with high PMS symptoms (Baker et al., 2008; Matsumoto et al., 2007). Fear conditioning studies have shown inconsistent associations with cycle phases, suggesting a complex interplay between physiological parameters and PMS-related symptoms (Carpenter et al., 2022; Epperson et al., 2007; Milad et al., 2006). The neurovisceral integration model posits that vmHRV reflects the capacity of the central autonomous network (CAN), which is responsible for regulatory processes on behavioral, cognitive, and autonomous levels (Thayer \& Lane, 2000, 2009). Fear learning, mediated within the CAN, is suggested to be indicative of vmHRV's capacity for successful VI regulation (Battaglia \& Thayer, 2022). Given the GABAergic mediation of central inhibitory functional connectivity in the CAN, which may be affected by ALLO fluctuations, this thesis proposes that fluctuating CAN activity in the luteal phase contributes to diverse aversive symptoms in PMS. A research program was designed to empirically test these propositions. Study 1 investigated fear discrimination during different menstrual cycle phases and its interaction with vmHRV, revealing nuanced effects on acoustic startle response and skin conductance response. While there was heightened fear discrimination in acoustic startle responses in participants in the luteal phase, there was an interaction between menstrual cycle phase and vmHRV in skin conductance responses. In this measure, heightened fear discrimination during the luteal phase was only visible in individuals with high resting vmHRV; those with low vmHRV showed reduced fear discrimination and higher overall responses. Despite affecting the vast majority of menstruating people, there are very limited tools available to reliably assess these symptoms in the German speaking area. Study 2 aimed at closing this gap, by translating and validating a German version of the short version of the Premenstrual Assessment Form (Allen et al., 1991), providing a reliable tool for future investigations, which closes the gap in PMS questionnaires in the German-speaking research area. Study 3 employed a diary study paradigm to explore daily associations between vmHRV and PMS symptoms. The results showed clear simultaneous fluctuations between the two constructs with a peak in PMS and a low point in vmHRV a few days before menstruation onset. The association between vmHRV and PMS was driven by psychological PMS symptoms. Based on the theoretical considerations regarding the neurovisceral perspective on PMS, another interesting construct to consider is attentional control, as it is closely related to functions of the CAN. Study 4 delved into attentional control and vmHRV differences between menstrual cycle phases, demonstrating an interaction between cycle phase and PMS symptoms. In a pilot, we found reduced vmHRV and attentional control during the luteal phase only in participants who reported strong PMS. While Studies 1-4 provided evidence for the mechanisms underlying PMS, Studies 5 and 6 investigated short- and long-term intervention protocols to ameliorate PMS symptomatology. Study 5 explored the potential of heart rate variability biofeedback (HRVB) in alleviating PMS symptoms and a number of other outcome measures. In a waitlist-control design, participants underwent a 4-week smartphone-based HRVB intervention. The results revealed positive effects on PMS, with larger effect sizes on psychological symptoms, as well as on depressive symptoms, anxiety/stress and attentional control. Finally, Study 6 examined the acute effects of HRVB on attentional control. The study found positive impact but only in highly stressed individuals. The thesis, based on this comprehensive research program, expands our understanding of PMS as an outcome of CAN fluctuations mediated by GABAA receptor reactivity. The results largely support the model. These findings not only deepen our understanding of PMS but also offer potential avenues for therapeutic interventions. The promising results of smartphone-based HRVB training suggest a non-pharmacological approach to managing PMS symptoms, although further research is needed to confirm its efficacy. In conclusion, this thesis illuminates the complex web of factors contributing to PMS, providing valuable insights into its etiological underpinnings and potential interventions. By elucidating the relationships between hormonal fluctuations, CAN activity, and psychological responses, this research contributes to more effective treatments for individuals grappling with the challenges of PMS. The findings hold promise for improving the quality of life for those affected by this prevalent and often debilitating condition.}, language = {en} } @misc{FreitagWeberSandersetal.2018, author = {Freitag, Nils and Weber, Pia Deborah and Sanders, Tanja Christiane and Schulz, Holger and Bloch, Wilhelm and Schumann, Moritz}, title = {High-intensity interval training and hyperoxia during chemotherapy}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {453}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414112}, pages = {7}, year = {2018}, abstract = {Introduction: We conducted a case study to examine the feasibility and safety of high-intensity interval training (HIIT) with increased inspired oxygen content in a colon cancer patient undergoing chemotherapy. A secondary purpose was to investigate the effects of such training regimen on physical functioning. Case presentation: A female patient (51 years; 49.1 kg; 1.65 m; tumor stage: pT3, pN2a (5/29), pM1a (HEP), L0, V0, R0) performed 8 sessions of HIIT (5 × 3 minutes at 90\% of Wmax, separated by 2 minutes at 45\% Wmax) with an increased inspired oxygen fraction of 30\%. Patient safety, training adherence, cardiorespiratory fitness (peak oxygen uptake and maximal power output during an incremental cycle ergometer test), autonomous nervous function (i.e., heart rate variability during an orthostatic test) as well as questionnaire-assessed quality of life (EORTC QLQ-C30) were evaluated before and after the intervention. No adverse events were reported throughout the training intervention and a 3 months follow-up. While the patient attended all sessions, adherence to total training time was only 51\% (102 of 200 minutes; mean training time per session 12:44 min:sec). VO2peak and Wmax increased by 13\% (from 23.0 to 26.1 mL min kg-1) and 21\% (from 83 to 100 W), respectively. Heart rate variability represented by the root mean squares of successive differences both in supine and upright positions were increased after the training by 143 and 100\%, respectively. The EORTC QLQ-C30 score for physical functioning (7.5\%) as well as the global health score (10.7\%) improved, while social function decreased (17\%). Conclusions: Our results show that a already short period of HIIT with concomitant hyperoxia was safe and feasible for a patient undergoing chemotherapy for colon cancer. Furthermore, the low overall training adherence of only 51\% and an overall low training time per session (∼13 minutes) was sufficient to induce clinically meaningful improvements in physical functioning. However, this case also underlines that intensity and/or length of the HIIT-bouts might need further adjustments to increase training compliance.}, language = {en} } @misc{TopcuFruehwirthMoseretal.2018, author = {Top{\c{c}}u, {\c{C}}ağda{\c{s}} and Fr{\"u}hwirth, Matthias and Moser, Maximilian and Rosenblum, Michael and Pikovskij, Arkadij}, title = {Disentangling respiratory sinus arrhythmia in heart rate variability records}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {913}, issn = {1866-8372}, doi = {10.25932/publishup-43631}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436315}, pages = {15}, year = {2018}, abstract = {Objective: Several different measures of heart rate variability, and particularly of respiratory sinus arrhythmia, are widely used in research and clinical applications. For many purposes it is important to know which features of heart rate variability are directly related to respiration and which are caused by other aspects of cardiac dynamics. Approach: Inspired by ideas from the theory of coupled oscillators, we use simultaneous measurements of respiratory and cardiac activity to perform a nonlinear disentanglement of the heart rate variability into the respiratory-related component and the rest. Main results: The theoretical consideration is illustrated by the analysis of 25 data sets from healthy subjects. In all cases we show how the disentanglement is manifested in the different measures of heart rate variability. Significance: The suggested technique can be exploited as a universal preprocessing tool, both for the analysis of respiratory influence on the heart rate and in cases when effects of other factors on the heart rate variability are in focus.}, language = {en} }