About

Germaine Cornelissen-Guillaume, PhD, is a professor in the Department of Integrative Biology and Physiology at the University of Minnesota. Her research focuses on how blood pressure and heart rate vary in response to stimuli in everyday life, with an emphasis on health surveillance and maintenance. She uses timing according to rhythms (chronobiologic principles) for assessing cardiovascular health and detecting pre-disease conditions early, aiming to optimize treatment schedules to reduce preventable heart attacks and strokes. Additionally, her work explores how solar cycles and changes in the Earth's radiation environment influence human physiology, which has implications for long-term space missions. Her extensive archives support research and education in chronobiology as it applies to various fields of medicine.

Research topics

• Medicine
• Internal medicine
• Mathematics
• Psychology
• Immunology
• Developmental psychology
• Physiology
• Psychiatry
• Social psychology
• Cardiology
• Clinical psychology

Selected publications

• About-Weekly Pattern in the Dynamic Complexity of a Healthy Subject’s Cellular Immune Activity: A Biopsychosocial Analysis

  Frontiers in Psychiatry · 2022 · 18 citations

  • Psychology
  • Developmental psychology
  • Clinical psychology

  In a previous integrative single-case study, we collected biological, psychological and social time-series data on a 25-year-old healthy woman over the course of 126 12-h intervals (63 days) and used urinary neopterin as an indicator of cellular immune activity [Schubert et al. 2012 ( 1 )]. The present re-evaluation introduced Dynamic Complexity (DC) as an additional non-linear and non-stationary measure to further investigate the subject’s biopsychosocial dynamics during the study. The new time series dealing with urinary neopterin complexity revealed a cyclic, circaseptan (about-weekly) repeating pattern (6.59 days). The only weekly reoccurring events over the course of the study that were associated with this immunological pattern were the in-depth interviews with the subject (mean distance between interviews: 6.5 days). Superposed epoch analysis (SEA) revealed a U-shaped relation between neopterin complexity and interviews, with a decrease in neopterin complexity before and during interviews and an increase after interviews. Furthermore, the complexity scores for irritation, anxiousness/depressiveness and mental activity were positively correlated with neopterin complexity. The results suggest that the interviews, which had been found to be related to the subject’s need for educational and/or social accomplishment, were marked by stress (decrease in psycho-immunological flexibility and adaptability), which was then relieved after the interviews (increase in psycho-immunological flexibility and adaptability). It appears that the subject’s cellular immune activity, as indicated by neopterin complexity, functionally mirrored the emotional meaning she ascribed to the in-depth interviews. This re-evaluation is in line with the view that biopsychosocial research requires multimodal analysis of single cases based on qualitative (e.g., in-depth interviews) and quantitative (e.g., time series analysis) data under conditions of “life as it is lived”.

  PublisherOA PDFDOI

• Abstract P139: Association Of Thoracic Aorta Calcification And Aortic Arch Stiffness: The Multi-ethnic Study Of Atherosclerosis

  Hypertension · 2022

  • Medicine
  • Cardiology
  • Internal medicine

  Background: Arterial stiffness (AS) is a robust risk factor for HTN and CVD. It remains unclear how thoracic aortic calcification (TAC) presence, volume, and density relate to AS in the aortic arch. Improved understanding of central AS may provide insight to future mechanistic approaches to prevent and control CVD. Methods: We evaluated 1,385 participants from MESA Exam 5 with TAC data throughout the thoracic aorta via Chest CT and pulse wave velocity (PWV) as a measure of AS across the aortic arch via MRI. We used linear regression models to assess cross-sectional associations of TAC presence, volume, and density with aortic arch PWV with adjustment for 1) age, sex, and race; and 2) age, sex, race, BMI, diabetes, estimated glomerular filtration rate, HTN-medication use, SBP, DBP, total cholesterol/high-density lipoprotein ratio, smoking status, CAC volume, CAC density, education, physical activity, and sedentary behavior. Results: Participants were a mean age of 69 years (SD 9) [717 (52%) female; 509 (37%) White, 359 (26%) Black, 285 (21%) Hispanic/Latino, and 232 (17%) Chinese]. Calcification was present in 1,263 (91%) and 1,228 (89%) participants in the entire thoracic aorta and aortic arch, respectively, compared to 848 (61%) and 138 (10%) in the descending and ascending aorta segments. Calcium volume in the entire thoracic aorta and aortic arch were highly correlated (r=0.94) with respective means of 866 (SD 1,724) and 564 (1,014) mm 3 . Mean PWV across the aortic arch was 9 m/sec (SD 4). After full adjustment, the presence of aortic arch calcification, compared to no aortic arch calcification, was associated with a 0.76 m/sec higher mean PWV (95% CI: 0.34 - 1.18; p<0.01), while a 1,000 mm 3 increment in aortic arch calcium volume was associated with 0.36 m/sec higher mean PWV (95% CI: 0.08-0.64; p=0.01). Results were similar when calcification in the entire thoracic aorta was the primary predictor variable. Conversely, there were no significant associations between mean or maximum calcium density measures and aortic arch PWV. Conclusion: TAC is highly prevalent in the thoracic aorta, especially the aortic arch. Calcification presence and higher calcification volume in the thoracic aorta, as well as the aortic arch itself, are associated with greater aortic arch AS.

  PublisherDOI

• Metabolomics Pilot Study Identifies Desynchronization of 24-H Rhythms and Distinct Intra-patient Variability Patterns in Critical Illness: A Preliminary Report

  Frontiers in Neurology · 2020 · 2 citations

  Senior authorCorresponding
  • Medicine
  • Physiology
  • Internal medicine

  In this pilot study, ICU patients' 24-h rhythms show significant desynchronization compared to healthy controls. Clustering of plasma metabolic profiles suggests that metabolomics could be used to track individual patients' clinical courses longitudinally. Our results show global disordering of metabolism and the circadian system in ICU patients which should be characterized further in order to determine implications for patient care.

  PublisherDOI

• Metabolomics pilot study identifies circadian desynchronization and distinct intra-patient variability patterns in critical illness

  medRxiv · 2019-12-14

  preprintOpen accessSenior author

  Abstract Background Synchronized circadian rhythms play a key role in coordinating physiologic health. Desynchronized circadian rhythms may predispose individuals to disease or be indicative of underlying disease. Intensive care unit (ICU) patients likely experience desynchronized circadian rhythms due to disruptive environmental conditions in the ICU and underlying pathophysiology. This observational pilot study was undertaken to determine if circadian rhythms are altered in ICU patients relative to healthy controls by profiling circadian rhythms in vital signs and plasma metabolites. Methods We monitored circadian rhythms in 5 healthy controls and 5 ICU patients for 24 hours. Heart rate and blood pressure were measured every 30 minutes, temperature was measured every hour, and blood was sampled for mass spectrometry-based plasma metabolomics every 4 hours. Bedside sound levels were measured every minute. Circadian rhythms were evaluated in vitals and plasma metabolites individually and in each group using the cosinor method. Results ICU patient rooms were significantly louder than healthy controls’ rooms and average noise levels were above EPA recommendations. Healthy controls generally had significant circadian rhythms individually and as a group. While a few ICU patients had significant circadian rhythms in isolated variables, no significant rhythms were identified in ICU patients as a group, except in cortisol. This indicates a lack of coherence in circadian phases and amplitudes among ICU patients. Finally, principal component analysis of metabolic profiles showed surprising patterns in plasma sample clustering. Each ICU patient’s samples were clearly discernable in individual clusters, separate from a single cluster of healthy controls. Conclusions ICU patients’ circadian rhythms show significant desynchronization compared to healthy controls. Clustering of plasma metabolic profiles suggests that metabolomics could be used to track individual patients’ clinical courses longitudinally. Our results show global disordering of metabolism and the circadian system in ICU patients which should be characterized further in order to determine implications for patient care.

  PublisherOA PDFDOI

• View point. 2018 guidelines of the indian society of chronomedicine provide a balanced view for acc/aha and international society of chronobiology controversies

  2018-01-01

  articleSenior author
  Publisher

• Omega-3-PUFA, omega-6-PUFA and mitochondrial dysfunction in relation to remodelling

  2018-01-01 · 2 citations

  articleSenior author
  Publisher

• Recent advances in mitochondrial medicine and Coenzyme Q10

  2018-01-01 · 15 citations

  article
  Publisher

• Pittfalls in the 2017 acc/aha consensus blood pressure guidelines and the role of 24-hour ambulatory blood pressure monitoring

  2017-01-01 · 1 citations

  articleSenior author
  Publisher

• Nobel prize in physiology or medicine recognizes the importance of circadian rhythms – remembering franz halberg and his everlasting legacy

  2017-01-01

  articleSenior author

• Mini-symposium remembering Franz Halberg held May 19, 2017 at the University of Minnesota

  2017-01-01

  article1st authorCorresponding
  Publisher

Frequent coauthors

• Franz Halberg

  University of Minnesota

  73 shared

• F Halberg

  University of Minnesota

  39 shared

• Jarmila Siègelovà

  Masaryk University

  31 shared

• Othild Schwartzkopff

  University of Minnesota

  30 shared

• Bohumil Fišer

  Masaryk University

  20 shared

• Ram B. Singh

  Jawaharlal Nehru Krishi Vishwa Vidyalaya

  18 shared

• George Katinas

  16 shared

• E. V. Syutkina

  15 shared

Labs

• Alejandro LabPI