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Overnight variability in transcutaneous carbon dioxide predicts vascular impairment in women
Author(s) -
Aittokallio Jenni,
Polo Olli,
Hiissa Jukka,
Virkki Arho,
Toikka Jyri,
Raitakari Olli,
Saaresranta Tarja,
Aittokallio Tero
Publication year - 2008
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2007.041277
Subject(s) - medicine , cardiology , brachial artery , intima media thickness , receiver operating characteristic , ultrasound , confounding , common carotid artery , carotid arteries , area under the curve , peripheral , carbon dioxide , blood pressure , radiology , ecology , biology
While there are a number of studies demonstrating association between arterial oxyhaemoglobin saturation events during sleep and markers of vascular impairment, the contribution of peripheral carbon dioxide to the development of atherosclerosis is poorly understood. We used ultrasound imaging to measure carotid artery intima–media thickness (IMT), as well as flow‐mediated dilatation (FMD) and nitroglycerin‐mediated dilatation (NMD) of brachial artery, in 103 generally healthy 46‐year‐old (±2 years) women. Characteristic event patterns were extracted from their overnight recordings of arterial oxyhaemoglobin saturation , end‐tidal partial pressure of carbon dioxide and transcutaneous partial pressure of carbon dioxide . Importance of the event patterns was evaluated through predictive modelling of classes of the ultrasound measurements while controlling for potential confounders. Prediction accuracy was assessed with cross‐validation and reported as the area under the receiver operating characteristic curve (AUC). Overnight patterns predicted each of the ultrasound measurements with high accuracy (IMT, AUC = 0.70; FMD, AUC = 0.75; and NMD, AUC = 0.81; all with P < 0.001). Adding the or patterns into the models did not significantly increase their predictive powers (AUC = 0.72, AUC = 0.77 and AUC = 0.83, respectively). The most important patterns reflected overnight variability in . These results suggest a novel link between overnight carbon dioxide events and early signs of vascular impairment in middle‐aged women. Non‐invasive measurements combined with non‐linear modelling techniques could be used to reveal potential markers of vascular impairment present in relatively healthy subjects.