Altitude and Breathing during Sleep in Healthy Persons and Sleep Disordered Patients: A Systematic Review.

Objetive The aim of this systematic review is to analyze the recent scientific evidence of the clinical effects of altitude on breathing during sleep in healthy persons and sleep disordered patients. Material and Methods A search was carried out in PubMed and Scopus looking for articles published between January 1, 2010 and December 31, 2021, in English and Spanish, with the following search terms: "sleep disorders breathing and altitude". Investigations in adults and carried out at an altitude of 2000 meters above mean sea level (MAMSL) or higher were included. The correlation between altitude, apnea hypopnea index (AHI) and mean SpO2 during sleep was calculated. Results 18 articles of the 112 identified were included. A good correlation was found between altitude and AHI (Rs = 0.66 P = 0.001), at the expense of an increase in the central apnea index. Altitude is inversely proportional to oxygenation during sleep (Rs = -0.93 P = 0.001), and an increase in the desaturation index was observed (3% and 4%). On the treatment of respiratory disorders of sleeping at altitude, oxygen is better than servoventilation to correct oxygenation during sleep in healthy subjects and acetazolamide controlled respiratory events and oxygenation during sleep in patients with obstructive sleep apnea under treatment with CPAP. Conclusions Altitude increases AHI and decreases oxygenation during sleep; oxygen and acetazolamide could be an effective treatment for sleep-disordered breathing at altitude above 2000 MAMSL.

Frequency of use and preferences for information and communication technologies in patients with sleep apnea: A multicenter, multinational, observational cross-sectional survey study.

BACKGROUND: Obstructive sleep apnea (OSA) is a condition characterized by repeated episodes of partial or complete obstruction of the upper airway during sleep. An accessible method to facilitate self-management education is through information and communication technologies (ICTs). PURPOSE: To assess the frequency of and preferences for ICT use in patients with sleep apnea. METHODS: A multicenter, multinational, observational cross-sectional survey study was conducted between 2018 and 2019 in sleep units in different countries of Latin America, including patients of both genders older than 18 years with a diagnosis of sleep apnea. Participants were asked to complete 20 questions in a self-administered survey about the frequency of use of ICTs and their preferences for receiving disease-related information. RESULTS: A total of 435 patients participated in the study, with a mean age of 59.1 ± 14.0; 62.5% (n = 272) were males. Most patients had access to cellphones (92.4%, n = 402), smartphone (83.0%, n = 361) and an internet connection (82.3%, n = 358). One-to-one ICTs were regarded as the most frequently used ICT type, as 75.4% (n = 328) of participants reported using them daily (χ2(4) = 848.207, p =.000). With respect to categories of interest, one-to-one ICTs were also the best rated ICT type to receive (59.1%, n = 257; χ2(2) = 137.710, p =.000) and ask physicians (57.0%, n = 248; χ2(2) = 129.145, p =.000) information about OSA. Finally, older adults and those with lower educational levels were found to be less likely to use and be interested in ICTs. CONCLUSION: Most patients have access to different ICTs and often use them to seek and receive medical information. The preferred ICTs include those in the one-to-one category (WhatsApp, email) and the one-to-many category (web browsers) for general health and OSA-related information.

Clinical Markers of Chronic Hypoxemia in Respiratory Patients Residing at Moderate Altitude.

Supplemental oxygen (SO) increases survival in hypoxemic patients. In hypoxia, mammals respond by modulating O2-sensitive transducers that stabilize the transcription factor hypoxia-inducible factor-1-alpha (HIF-1α), which transactivates the genes that govern angiogenesis and metabolic pathways. Residing at high altitudes exposes millions of people to hypoxemia with potential adverse consequences on their health. We aimed to identify markers of hypoxemia that can be used in the evaluation of patients in addition to pulse oximetry and arterial blood gases, especially those that could respond after 1 month of oxygen use. We performed a prospective pilot study at 2240 m above sea level, with repeated measurements before and after (b/a) 1-month home oxygen therapy in 70 patients with lung diseases, of which 24/20 have COPD, 41/39 obstructive sleep apnea (OSA), and 5/2 with interstitial lung diseases (ILD), all of them having chronic hypoxemia, as well as 70 healthy subjects as controls. Proteins evaluated included HIF-1α, vascular endothelial growth factor (VEGF), and erythropoietin (EPO). Among the main results, we found that hypoxemic patients had normal levels of HIF-1α but increased EPO compared with healthy controls. VEGF levels were heterogeneous in the sample studied, similar to the control group in COPD, slightly increased in OSA, and decreased in fibrosis. With oxygen treatment, the HIF-1α and EPO decreased in COPD and OSA but not in fibrosis, and VEGF remained constant over time. In conclusion, erythropoietin and HIF-1α identified hypoxemia initially and responded to oxygen. In pulmonary fibrosis, HIF-1α, EPO, and VEGF increased with oxygen therapy, which is likely linked to the disease's pathogenesis and clinical course rather than hypoxemia.