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.

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Aim The primary aim of this study was to examine the impact of age, gender and the stage of dementia on the results of an assistive technology intervention that make use of communication robots (com‐robots). The intervention was designed to improve the social participation and interactions of nursing home residents. While our previous study showed that the overall effects of com‐robot intervention were positive, it was unknown what impact age, gender and the stage of dementia of participants had on such an intervention. Methods This was a non‐randomized, multicenter quasi‐experimental intervention study conducted in residential care homes in Japan. Two types of com‐robots were introduced for 8 weeks after baseline evaluation. The World Health Organization's ICF was used for evaluating any changes present after the 8‐week intervention. In total, 78 residents (68 women, 10 men, 86.5 ± 7.7 years old) participated in the study. The Degree of Daily Life Independence Score for People with Dementia (DDLIS‐PD) was employed for measuring the stage of dementia. Results The results showed that the older participants aged ≥80 benefited more from the intervention than the younger cohort did (P < 0.05). A greater improvement was shown among those with a more advanced stage of dementia than those at a less advanced stage (P < 0.05), when using DDLIS‐PD. Conclusions The overall findings support the use of com‐robots within the context of a care team for older people with moderate dementia, and those who are aged ≥80 years. Geriatr Gerontol Int 2020; 20: 373–378.

To determine the relationship between periodic breathing (PB) during sleep at high altitude and ventilatory chemosensitivities, we studied nine Japanese climbers who participated in the expedition to the Kunlun Mountains (7,167m) in China in 1986. At sea level, ventilatory response to hypoxia (HVR) by isocapnic progressive hypoxia test and to hypercapnia (HCVR) by Read's method were examined. At altitude 5,360 m, respiratory movements of the chest and abdominal wall, Saoz, ECG, and HR were monitored. Seven climbers manifested PB during sleep. There was a significant correlation between PB during sleep and HVR and HCVR (p <0.05). All the climbers showed severe desaturation during sleep. There was a significant negative correlation between degree of desaturation during sleep and HVR (p <0.05). A negative correlation was also detected between PB and the degree of desaturation during sleep. We concluded that ventilatory chemosensitivities play an important role in eliciting PB and that climbers with high HVR can maintain their arterial oxygenation during sleep, due to hyperventilation induced by PB, which is considered an advantageous adaptation for lowland sojourners.

Sixteen healthy volunteers breathed 100% O2 or room air for 10 min in random order, then their ventilatory response to sustained normocapnic hypoxia (80% arterial O2 saturation, as measured with a pulse oximeter) was studied for 20 min. In addition, to detect agents possibly responsible for the respiratory changes, blood plasma of 10 of the 16 subjects was chemically analyzed. 1) Preliminary O2 breathing uniformly and substantially augmented hypoxic ventilatory responses. 2) However, the profile of ventilatory response in terms of relative magnitude, i.e., biphasic hypoxic ventilatory depression, remained nearly unchanged. 3) Augmented ventilatory increment by prior O2 breathing was significantly correlated with increment in the plasma glutamine level. We conclude that preliminary O2 administration enhances hypoxic ventilatory response without affecting the biphasic response pattern and speculate that the excitatory amino acid neurotransmitter glutamate, possibly derived from augmented glutamine, may, at least in part, play a role in this ventilatory enhancement.