Nocturnal transcutaneous carbon dioxide tension in postmenopausal estrogen users and non-users

: Aittokallio J, Hiissa J, Saaresranta T, Polo-Kantola P, Aittokallio T, Polo O

: 2009

: Menopause International

: Menopause international

: Menopause Int

: 15

: 3

: 107

: 12

: 1754-0453

DOI: https://doi.org/10.1258/mi.2009.009028

The effect of menopause on breathing is not fully understood. We have previously shown that postmenopausal women have a higher sleep-induced increase in transcutaneously measured carbon dioxide tension (TcCO(2)) than premenopausal women. Therefore, we hypothesized that estrogen therapy (ET) would normalize this sleep-induced TcCO(2) increase.\nNine postmenopausal ET users and nine non-users went through an overnight polygraphic sleep study including continuous monitoring of TcCO(2).\nTcCO(2) levels were higher during sleep than evening wakefulness (awake median 6.55 kPa versus sleep median 6.90 kPa, P = 0.001). ET users had a greater sleep-induced increase in TcCO(2) than non-users when comparing the difference between wakefulness and slow-wave sleep (0.85 kPa versus 0.28 kPa, P = 0.004). Lower sleep efficiency was associated with higher sleep-induced increase in TcCO(2).\nIn contrast to our initial hypothesis, postmenopausal ET users have a higher sleep-induced increase in TcCO(2) than women without ET. Thus, TcCO(2) may be sensitive in measuring the peripheral estrogen effect. These findings warrant placebo-controlled intervention studies to confirm the effects of ET on TcCO(2) measurements.\nOBJECTIVE\nMETHODS\nRESULTS\nCONCLUSIONS