Human breath isoprene and its relation to blood cholesterol levels: new measurements and modeling
| Autor: | P. Prazeller, Werner Lindinger, Dagmar Mayr, Josef Rieder, Ray Fall, Thomas Karl, Alfons Jordan |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Cholesterol synthesis
medicine.medical_specialty Time Factors Physiology Physical Exertion Posture Models Biological Mass Spectrometry chemistry.chemical_compound Hemiterpenes Breath rate Heart Rate Physiology (medical) Internal medicine Pentanes Heart rate Respiration medicine Atorvastatin Butadienes Humans Pyrroles Exercise physiology Exercise Isoprene Proton-transfer-reaction mass spectrometry Monitoring Physiologic Anticholesteremic Agents digestive oral and skin physiology Lipoproteins LDL Cholesterol chemistry Biochemistry Breath Tests Heptanoic Acids Blood cholesterol Cardiology Respiratory Mechanics Sleep |
| Zdroj: | ResearcherID |
| ISSN: | 8750-7587 |
| Popis: | Numerous publications have described measurements of breath isoprene in humans, and there has been a hope that breath isoprene analyses could be a noninvasive diagnostic tool to assess blood cholesterol levels or cholesterol synthesis rate. However, significant analytic problems in breath isoprene analysis and variability in isoprene levels with age, exercise, diet, etc., have limited the usefulness of these measurements. Here, we have applied proton transfer reaction-mass spectrometry to this problem, allowing on-line detection of breath isoprene. We show that breath isoprene concentration increases within a few seconds after exercise is started as a result of a rapid increase in heart rate and then reaches a lower steady state when breath rate stabilizes. Additional experiments demonstrated that increases in heart rate associated with standing after reclining or sleeping are associated with increased breath isoprene concentrations. An isoprene gas-exchange model was developed and shows excellent fit to breath isoprene levels measured during exercise. In a preliminary experiment, we demonstrated that atorvastatin therapy leads to a decrease in serum cholesterol and low-density-lipoprotein levels and a parallel decrease in breath isoprene levels. This work suggests that there is constant endogenous production of isoprene during the day and night and reaffirms the possibility that breath isoprene can be a noninvasive marker of cholesterologenesis if care is taken to measure breath isoprene under standard conditions at constant heart rate. |
| Databáze: | OpenAIRE |
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