Eur Respir J 2009; 34:1132-1139 Copyright ©ERS Journals Ltd 2009 doi: 10.1183/09031936.00017909
Transcutaneous carbon dioxide profile during sleep reveals metabolic risk factors in post-menopausal females1 Sleep Research Unit, Dept of Physiology, 3 Biomathematics Research Group, Dept of Mathematics, 4 Paavo Nurmi Centre, Dept of Physiology, University of Turku, 2 Dept of Pulmonary Diseases, Turku University Central Hospital, Turku, and 5 Dept of Pulmonary Diseases, Tampere University Hospital, Tampere, Finland. CORRESPONDENCE: J. Aittokallio, Sleep Research Unit, University of Turku, Lemminkäisenkatu 14-18 A, FI-20014, Turku, Finland. E-mail: jemato{at}utu.fi Keywords: Metabolic syndrome, post menopause, sleep, transcutaneous carbon dioxide
Received: February 2, 2009
The risks of metabolic syndrome and sleep-disordered breathing increase around the time of the menopause. We have previously shown that features of the nocturnal transcutaneous carbon dioxide (TcCO2) profile are associated with metabolic variables such as cholesterol, glycosylated haemoglobin A1C (GHbA1C) and blood pressure in patients with sleep apnoea. In the present study, we investigated whether these metabolic variables can be predicted using noninvasive TcCO2 measurements during sleep in generally healthy post-menopausal females.
22 post-menopausal females underwent an overnight polygraphic sleep study that involved the continuous monitoring of arterial oxygen saturation (Sa,O2) and TcCO2. Body composition, GHbA1C, plasma cholesterol and blood pressure were measured prior to the sleep study.
Nocturnal TcCO2 features were the most important predictors of lipoprotein cholesterols, triglycerides and blood pressure levels. A longer sleep period and higher TcCO2 levels were linked with lower GHbA1C, and fragmented sleep with lower high-density lipoprotein cholesterol. Neither nocturnal Sa,O2 indices nor the apnoea/hypopnoea index had a predictive power.
The results suggest that nocturnal TcCO2 events revealed metabolic risk factors already present in healthy post-menopausal females.
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