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Study shows even cumulative hypoxemia

(not necessarily sleep apnea) is detrimental for endothelial function and should be treated

Heart Vessels. 2020 Jan 21.

Accumulated nocturnal hypoxemia predicts arterial endothelial function in patients with sleep-disordered breathing with or without chronic heart failure.

Sawatari H1,2, Chishaki A1, Nishizaka M3,4, Miyazono M1,5, Tokunou T4, Magota C6, Yamamoto U7,8, Handa SS7,9, Ando SI10.

1 Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.

2 Department of Health Care for Adult, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

3 Department of Cardiovascular Medicine, Kimura Hospital, Fukuoka, Japan.

4 Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.

5 Department of Nursing, Faculty of Nursing, Fukuoka Nursing College, Fukuoka, Japan.

6 School of Nursing, Kurume University, Fukuoka, Japan.

7 Sleep Apnea Center, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka, 812-8582, Japan.

8 Department of Cardiology, General Internal Medicine, Onga Hospital, Fukuoka, Japan.

9 Kirameki Projects Career Support Center, Kyushu University Hospital, Fukuoka, Japan.

10 Sleep Apnea Center, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka, 812-8582, Japan.


Sleep-disordered breathing (SDB) is often accompanied with the chronic heart failure (CHF). Hypoxemia due to pulmonary congestion from CHF and concurrent SDB might synergistically impair endothelial function and worsen the prognosis. However, the main factors affecting deterioration of endothelial function are unknown and whether the influence of hypoxemia differs in SDB patients with and without CHF remains unclear. Fifty-three patients (CHF group, n = 23; non-CHF group, n = 30) underwent polysomnography to evaluate their SDB and flow-mediated vasodilation (FMD) measurements to assess arterial endothelial function. We examined the relationships between FMD and SDB-related parameters, including our original index of accumulated hypoxemia by SDB throughout one-night sleep: the time desaturation summation index (TDS), calculated as follows: (100% - averaged arterial oxygen saturation during sleep) × total sleep time. The mean age in the CHF and non-CHF groups was 59.0 ± 13.5 and 57.7 ± 11.4 years, respectively. Although the FMD in the 2 groups were not significantly different, well-known adverse factors for FMD such as serum lipid profiles, blood pressure levels, and conventional indices of SDB were worse in the non-CHF group. Only the TDS was not significantly different between 2 groups and associated with FMD as shown by the univariate analysis (CHF: p < 0.05, non-CHF: p < 0.01) and multivariate analysis (CHF: p < 0.05, non-CHF: p < 0.01).

Accumulated hypoxemia (TDS) rather than the frequency of hypoxemia might more influence on the endothelial function irrespective of the cardiac state. Removal of accumulation of nocturnal hypoxemia might be a target for treatment equally in the patients with and without CHF.


Endothelial function; Heart failure; Hypoxemia; Sleep-disordered breathing


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