A pilot study on exercise induced changes in cellular oxygen metabolism measured by the Cellular Oxygen METabolism Monitor (COMET)
- Conditions
- healthy controls
- Registration Number
- DRKS00014033
- Lead Sponsor
- WG Translational Septomics, Zentrum für Innovationskomepetenz (ZIK) Septomics, Universitätklinikum Jena
- Brief Summary
Impaired tissue oxygenation is the key pathomechanism in the development of organ dysfunction in shock; mitochondrial impairment can aggravate the condition. However, measuring tissue oxygenation directly and non-invasively still poses a clinical challenge. A novel device (COMET) allows the assessment of mitochondrial oxygen metabolism using the Protoporphyrin IX Triplet State Lifetime Technique (PpIX-TSLT). Critically ill patients, especially in sepsis, often exhibit oedema which may interfere with the COMET measurement. Furthermore, patients' physical activity level differs significantly before and during hospitalisation. Thus, the aim of this study was to identify the effects of physical activity and body composition on mitochondrial oxygen tension (mitoPO2) and consumption (mitoVO2) in healthy controls (N = 40). Furthermore, the study tested the repeatability of the COMET variables and identified covariates. Multiple COMET measurements were performed before (T1, T2), during and after (T3, T4) ergometry. Body composition was assessed by bioimpedance analysis. Physiological variables (blood pressure, heart rate, oxygen saturation) were recorded. In the analytical sample (n = 26), physical activity significantly decreased mitoVO2; other COMET variables remained unchanged between T2 and T3. During ergometry, mitoPO2 increased significantly. The distribution of body water significantly influenced mitoVO2. In our setting, the method demonstrated moderate repeatability. Variables of fitness (heart rate recovery, phase angle and physical activity level), signal quality and duration of exposure to 5-aminolevulinic acid (obligatory for PpIX-TSLT) were identified as significant covariates of mitoVO2. Mitochondrial oxygen delivery (mitoDO2) was established as a new variable of COMET analysis. Results of this pilot study should be validated in future studies.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Complete
- Sex
- All
- Target Recruitment
- 40
age >18 years
- written and informed consent
- suitability for exercise test (Physical Activity Readiness Questionnaire)
- significant pre-existing cardiological or pulmonal disease as well as significant diseases of the musculoskeletal system
-absolute contraindication for 5-aminolevulinic-acid-patch (for COMET measurement):
allergy to 5-aminolevulinic-acid-hydrocholride, acrylic adhesives, pigmented polyethylene or aluminized polyester
- porphyria, skin disease which are caused or aggravated by sun light, increased sensitivity to sun light
- pregnancy/breastfeeding
- participation in another intervention study
- previous participation in this study
Study & Design
- Study Type
- interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Differences in mitoPO2 and mitoVO2 between second baseline-measurement (T2) und first measurement after exercise (T3)
- Secondary Outcome Measures
Name Time Method Evaluation of stability of mitoPO2 and mitoVO2 between T1 and T2 as well as between baseline-measurements (T1, T2) and T4<br><br>Exploratory analysis on effects of age and sex on mitoPO2 and mitoVO2 at T1, T2 and T4<br><br>Exploratory analysis on effects of the bioelectrical impedance analysis parameters on mitoPO2 and mitoVO2 at T1, T2 and T4<br><br>Data collection for the methodical validation of the contactless assessment of oxygen saturation.