Manifestation of Pulmonary Hypertension During REM Sleep in Obstructive Sleep Apnea Syndrome

Abstract

The effect of sleep stage change on pulmonary circulation has not been well documented in patients with obstructive sleep apnea syndrome (OSAS). We investigated whether or not stage-specific change can affect pulmonary artery pressure (Ppa) in patients with OSAS. Thirty-one patients with OSAS underwent right cardiac catheterization in the daytime and the following night, including 19 patients in whom Ppa could be measured throughout non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Ten of the 19 patients had daytime pulmonary hypertension (PH) defined by a mean Ppa (Ppa) >/= 20 mm Hg. Then we analyzed Ppa response to hypoxia spontaneously occurring during the period of sleep apnea. The slopes of the regression lines between arterial oxygen saturation measured by pulse oximeter (SpO2) and Ppa curves were almost the same in both NREM and REM patient groups with or without daytime PH, whereas the response curve was significantly shifted upward in REM compared with NREM patients with daytime PH. Furthermore, Ppa was elevated more markedly in association with REM burst, phasic REM, compared with tonic REM. We conclude that vascular tone of pulmonary artery could be elevated in association with REM sleep which is independent of the degree of hypoxia, and that this state-specific change is manifested in patients with daytime PH.

Präkapilläre pulmonale Hypertonie und schlafbezogene Atmungsstörungen: Gibt es einen Zusammenhang?

“…In der Phase des REM (rapid eye movement)-Schlafs wird der Pulmonalarteriendruck (pulmonary artery pressure, PAP) instabil und steigt im Vergleich zum NREM-Schlaf an [10]. Jedoch wurden beim PAP gesunder Personen keine relevanten Unterschiede zwischen der ersten und der zweiten Hälfte einer durchschlafenen Nacht festgestellt, was darauf hindeuten könnte, dass der PAP nicht vom NREM- oder REM-Schlaf abhängig ist [11].…”

Precapillary Pulmonary Hypertension and Sleep-Disordered Breathing: Is There a Link?

“…In rapid eye movement (REM) sleep, pulmonary arterial pressure (PAP) becomes unstable and increases compared to NREM sleep [10]. However, no relevant differences in PAP were seen between the first and the second half of a night in healthy individuals, which may indicate a lack of dependence of PAP on NREM and REM sleep stage [11].…”

“…Moreover, major rises in both systemic and PAP during long apneas in phasic REM sleep have been described (Fig. 2) [10]. The large arterial pressure swings associated with sympathetic overstimulation in OSA patients induce vascular shear stress and promote endothelial dysfunction [35,36,37].…”

“…2 Example of polysomnographic recording during phasic and tonic rapid eye movement (REM) sleep. There are major rises in both systemic and pulmonary artery pressure (arrows) during apneas in phasic REM sleep (adapted from Niijima et al [10]). Abdo., abdomen; HR, heart rate; PAP, pulmonary artery pressure; Psa, systemic arterial pressure. …”

Supplemental Oxygen Needs During Sleep. Who Benefits?

“…Although less well studied, there are also important hemodynamic changes that occur with sleep state changes, but that seem to be independent of changes in oxygen saturation or P CO 2 . 21 In addition to other cardiovascular changes during REM sleep, pulmonary artery pressures increase out of proportion to blood gas abnormalities.…”