High-flow nasal cannula oxygen reduced hypoxemia in patients undergoing gastroscopy under general anesthesia at ultra-high altitude: a randomized controlled trial.

BACKGROUND: Hypoxemia can occur in people at ultra-high altitude (above 3500 m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15 L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60 L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. METHODS: The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15 min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60 s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline. RESULTS: A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14-0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67-1.69) ; P = 0.779]. CONCLUSION: HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude.

The mediation role of blood lipids on the path from air pollution exposure to MAFLD: A longitudinal cohort study.

BACKGROUND & AIMS: Recent cross-sectional studies found that exposure to ambient air pollution (AP) was associated with an increased risk of metabolic dysfunction-associated fatty liver disease (MAFLD). The alternation of blood lipids may explain the association, but epidemiological evidence is lacking. We aimed to examine whether and to what extent the association between long-term exposure to AP and incident MAFLD is mediated by blood lipids and dyslipidemia in a prospective cohort. METHODS: We included 6350 participants from the China Multi-Ethnic Cohort (CMEC, baseline 2018-2019, follow-up 2020-2021). Three-year average (2016-2018) of AP (PM1, PM2.5, PM10, NO2), blood lipids (TC, LDL-C, HDL-C, TG with their combinations) and incident MAFLD for each individual were assessed chronologically. Linear and logistic regression was used to assess the associations among AP, blood lipids, and MAFLD, and the potential mediation effects of blood lipids were evaluated using causal mediation analysis. RESULTS: A total of 744 participants were newly diagnosed with MAFLD at follow-up. The odds ratios of MAFLD associated with a 10 µm increase in PM1, PM2.5, and NO2 were 1.35 (95 % CI: 1.14, 1.58), 1.34 (1.10, 1.65) and 1.28 (1.14, 1.44), respectively. Blood lipids are important mediators between AP and incident MAFLD. LDL-C (Proportion Mediated: 6.9 %), non-HDL (13.4 %), HDL-C (20.7 %), LDL/HDL (30.1 %), and dyslipidemia (6.5 %) significantly mediated the association between PM2.5 and MAFLD. For PM1, the indirect effects were similar to those for PM2.5, with a larger value for the direct effect, and the mediation proportion by blood lipids was less for NO2. CONCLUSION: Blood lipids are important mediators between AP and MAFLD, and can explain 5 %-30 % of the association between AP and incident MAFLD, particularly cholesterol-related variables, indicating that AP could lead to MAFLD through the alternation of blood lipids. These findings provided mechanical evidence of AP leading to MAFLD in epidemiological studies.

Optimal Duration of High-Fidelity Simulator Training for Bronchoscope-Guided Intubation: A Noninferiority Randomized Trial.

INTRODUCTION: The optimal simulator training duration for flexible optical bronchoscopic (FOB) intubation is unknown. This study aimed to determine whether a learning curve-based training modality was noninferior to a fixed training time modality in terms of clinical FOB intubation time. METHODS: This multicenter, randomized, noninferiority study was conducted from May to August 2022. Anesthesiology residents or interns were enrolled. Eligible participants were randomized in a 1:1 ratio to receive new learning curve-based simulator training (individualized training time based on performance, group New) or reference fixed training time simulator training (1 hour, group Reference). The primary outcome was the time to complete FOB intubation in patients, which was defined as the time from the introduction of the FOB into the mouth until the first capnography visualization. The margin for detecting clinical significance was defined as 10 seconds. RESULTS: A total of 32 participants were included in the analysis (16 in each group). All trainees successfully intubated the patients. The mean intubation time (95% confidence interval [CI]) was 81.9 (65.7-98.1) seconds in group New and 97.0 (77.4-116.6) seconds in group Reference. The upper bound of the 1-sided 97.5% CI for the mean difference of clinical intubation time between groups was 9.3 seconds. Noninferiority was claimed. The mean duration of the training in group New was 28.4 (95% CI, 23.5-33.4) minutes. The total number of training procedures on simulators in group New was significantly less than that in group Reference (P < 0.01). CONCLUSIONS: The clinical FOB intubation time in group New was noninferior to that in group Reference.

[Exploration and practice on construction of Tibetan medicine prescription information database and knowledge discovery].

This study aimed to explore the underlying framework and data characteristics of Tibetan prescription information. The information on Tibetan medicine prescriptions was collected based on 11 Tibetan medicine classics, such as Four Medical Canons(Si Bu Yi Dian). The optimal classification method was used to summarize the information structure of Tibetan medicine prescriptions and sort out the key problems and solutions in data collection, standardization, translation, and analysis. A total of 11 316 prescriptions were collected, involving 139 011 entries and 63 567 pieces of efficacy information of drugs in prescriptions. The information on Tibe-tan medicine prescriptions could be summarized into a "seven-in-one" framework of "serial number-source-name-composition-efficacy-appendix-remarks" and 18 expansion layers, which contained all information related to the inheritance, processing, origin, dosage, semantics, etc. of prescriptions. Based on the framework, this study proposed a "historical timeline" method for mining the origin of prescription inheritance, a "one body and five layers" method for formulating prescription drug specifications, a "link-split-link" method for constructing efficacy information, and an advanced algorithm suitable for the research of Tibetan prescription knowledge discovery. Tibetan medicine prescriptions have obvious characteristics and advantages under the guidance of the theories of "three factors", "five sources", and "Ro-nus-zhu-rjes" of Tibetan medicine. Based on the characteristics of Tibetan medicine prescriptions, this study proposed a multi-level and multi-attribute underlying data architecture, providing new methods and models for the construction of Tibetan medicine prescription information database and knowledge discovery and improving the consistency and interoperability of Tibetan medicine prescription information with standards at all levels, which is expected to realize the "ancient and modern connection-cleaning up the source-data sharing", so as to promote the informatization and modernization research path of Tibetan medicine prescriptions.

Diverse associations between adiposity and blood pressure among 80,000 multi-ethnic Chinese adults.

BACKGROUND: Adiposity is widely recognized as one of the risk factors for high blood pressure (BP) and increasing adiposity is associated with elevated BP. However, which measures of adiposity could be most strongly associated with BP in multi-ethnic population remains uncertain, giving rise to implications that population-based adiposity measures could be necessary. METHODS: 80,000 multi-ethnic adults recruited from 5 provinces across Southwest China during 2018 ~ 2019 were studied. Multiple linear regression was applied to investigate the associations of systolic blood pressure (SBP) with: (1) two measures of general adiposity, body mass index (BMI) and height-adjusted weight; and (2) three measures of central adiposity, waist circumference (WC), hip circumference (HC) and waist hip ratio (WHR). RESULTS: Two distinct population-specific patterns were identified, as "BMI to SBP" and "WC to SBP". 90% of the participants fall into "BMI to SBP" pattern, in which the associations of SBP with BMI were independent of WC, and SBP-WC associations were considerably decreased by adjustment for BMI. And in this pattern, 10 kg/m2 greater BMI was associated with 11.9 mm Hg higher SBP on average. As for the rest population (Han males in Yunnan and Tibetans in Lhasa), they are suited for "WC to SBP" pattern, 10 cm wider WC was associated with 3.4 mm Hg higher SBP. CONCLUSION: Our results indicated that when selecting proper predictors for BP, population-specific adiposity measures are needed, considering ethnicity, sex and residing regions. A better understanding of adiposity and BP may better contribute to the potential clinical practices and developing precision application strategies.

Supraglottic jet oxygenation and ventilation decreased hypoxemia during gastrointestinal endoscopy under deep sedation at high altitudes: a randomized clinical trial.

BACKGROUND: Hypobaric hypoxia is common at high altitudes. Whether this exacerbates hypoxia during procedural sedation and whether hypoxia can be alleviated by the use of supraglottic jet oxygenation and ventilation (SJOV) are unknown. This study aimed to compare the incidence of hypoxia during gastrointestinal endoscopy under deep sedation at high altitudes with oxygen supply techniques using either a nasal cannula or SJOV. METHODS: This study was conducted from April 2022 to July 2022 in a tertiary hospital located 3650 m above sea level. Adult patients scheduled for routine gastrointestinal endoscopy under sedation were enrolled and randomized 1:1 to receive SJOV or a nasal cannula during sedation. Moderate hypoxia was the primary outcome, defined as an SPO2 of 75-89% for < 60 s. The secondary outcomes were respiratory-, cardiovascular-, and SJOV-related complications. The influence of characteristics regarding acclimatization to high altitudes (Tibetan ethnic group and erythrocytosis) on the occurrence of hypoxia was analyzed. RESULTS: None of the patients were lost to follow-up. A total of 72 patients were included in the analysis (36 patients in each group). There were 20 (27.8%) patients who experienced moderate hypoxia events. Significantly fewer hypoxic events occurred in the SJOV group than in the nasal cannula group [3 (8.3%) vs. 17 (47.2%), absolute risk difference (95% CI): - 38.9 (- 57.5, - 20.2) %, risk ratio (RR, 95% CI): 0.18 (0.06, 0.55), P < 0.001]. Significantly fewer patients in the SJOV group experienced mild hypoxia (P < 0.001) and severe hypoxia (P = 0.002). No serious adverse events occurred in either of the groups. The Tibetan ethnic group (P = 0.086) and erythrocytosis (P = 0.287) were not associated with the occurrence of hypoxia events. CONCLUSIONS: The incidence of hypoxia was lower with SJOV than with nasal cannula in patients undergoing gastrointestinal endoscopy under deep sedation at high altitudes. The Tibetan ethnic group and erythrocytosis did not influence the occurrence of hypoxia. TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov (NCT05304923) before enrollment by Dr. Yi Feng on 31/03/2022.

Associations between long-term exposure to ambient air pollution and renal function in Southwest China: The China Multi-Ethnic Cohort (CMEC) study.

BACKGROUND: Limited studies have examined associations between air pollutants exposure and renal function, especially in China, with the most extensive chronic kidney disease (CKD) disease burden worldwide. OBJECTIVES: This study examines associations between long-term exposure to ambient PM2.5, NO2, CO, O3, SO2 and renal function. METHODS: We included 80,225 participants aged 30-79 years from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Three-year average concentrations of PM2.5, NO2, CO, O3, and SO2 were estimated using satellite-based spatiotemporal models. Renal function is determined by the estimated glomerular filtration rate (eGFR) using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. After adjusting for covariates, generalized propensity scores (GPS) weighting regression was used to estimate associations between ambient air pollutants and renal function. RESULTS: An increase of 0.1 mg/m3 CO (OR [odds ratio] =1.20 95% CI [confidence interval], 1.05-1.37) was positively associated with CKD. An increase of 1 µg/m3 in SO2 (1.07, 1.00-1.14) concentration was positively associated with CKD. An increase of 10 µg/m3 in PM2.5 (1.17, 0.99-1.38), NO2 (1.12, 0.83-1.51) and O3 (1.10, 0.81-1.50) concentration was not associated with CKD. These effects are stronger in those younger than 65, smoking and with low BMI. CONCLUSIONS: In this study, we found that long-term exposure to ambient CO and SO2 were positively associated with CKD. Gaseous pollutants should also arouse the concern of relevant departments.

Ethnic disparities in the association between ambient air pollution and risk for cardiometabolic abnormalities in China.

BACKGROUND: Long-term exposure to ambient air pollution has been associated with cardiometabolic abnormalities (CAs), which, however, may be stronger in vulnerable populations, such as minorities. The variation of the association between ambient air pollution and CAs between the majority (Han) and minority populations in China have been poorly studied. OBJECTIVES: We aimed to estimate and compare the Hans' and minorities' risks for CAs associated with long-term exposure to ambient air pollution in Southwest China. METHODS: A cross-sectional study was conducted on the basis of the China Multi-Ethnic Cohort. CAs were defined by the presence of at least three pre-defined metabolic dysfunctions (central obesity, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose). The concentrations of ambient air pollutants, including particulate matters (PM1, PM2.5, and PM10) and nitrogen dioxide (NO2), were generated from random forest models on the basis of multi-source data. One- and two-pollutant regression models were fit to assess associations between air pollutant exposure and CA risks. Sensitivity analyses were performed to examine the robustness of the associations. RESULTS: The final sample included 51,037 Hans and 28,702 minority participants. The prevalence of CAs was 25.0%, slightly higher in the minorities (25.5%) than the Hans (24.4%). The higher risks for CAs in the overall population were associated with each 10 µg/m3 increase in the exposure to PM1 (OR = 1.07 [1.05-1.09]), PM2.5 (OR = 1.11 [1.06-1.17]), PM10 (OR = 1.04 [1.03-1.06]), and NO2 (OR = 1.04 [1.03-1.07]). Compared to the Hans, the higher risks for CAs were observed in the minorities for PM1 (OR = 1.35 [1.18-1.53]), PM2.5 (OR = 1.61 [1.34-1.93]), and PM10 (OR = 1.15 [1.07-1.23]). The associations of metabolic dysfunctions (CA components) with ambient air pollution also varied between the Han and minority populations. CONCLUSIONS: The associations between exposure to ambient air pollution and CA risks were stronger in the minorities than Hans. Our findings provide a better understanding of ethnic disparities in CA risks when being exposed to ambient air pollution in China, which also have important implications for other low- and middle-income countries where less health resources (e.g., cohort populations) are available to conduct such studies.

Crocin Improves Endothelial Mitochondrial Dysfunction via GPx1/ROS/KCa3.1 Signal Axis in Diabetes.

Mitochondrial dysfunction contributes to excessive reactive oxygen species (ROS) generation, which is a dramatic cause to promote endothelial dysfunction in diabetes. It was previously demonstrated that crocin protected the endothelium based on its diverse medicinal properties, but its effect on the mitochondrion and the potential mechanism are not fully understood. In this study, mitochondrial function was analyzed during the process of excessive ROS generation in high glucose (HG)-cultured human umbilical vein endothelial cells (HUVECs). The role played by KCa3.1 was further investigated by the inhibition and/or gene silence of KCa3.1 in this process. In addition, nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase 2 (NOX2), superoxide dismutase 1 (SOD1), and glutathione peroxidase 1 (GPx1) were also detected in this study. Our data showed that crocin improved mitochondrial dysfunction and maintained normal mitochondrial morphology by enhancing the mitochondrial membrane potential (MMP), mitochondrial mass, and mitochondrial fusion. Furthermore, KCa3.1 was confirmed to be located in the mitochondrion, and the blockade and/or silencing of KCa3.1 improved mitochondrial dysfunction and reduced excessive ROS generation but did not affect NOX2 and/or the SOD1 system. Intriguingly, it was confirmed that KCa3.1 expression was elevated by ROS overproduction in the endothelium under HG and/or diabetes conditions, while crocin significantly suppressed this elevation by promoting GPx1 and subsequently eliminating ROS generation. In addition, crocin enhanced CD31, thrombomodulin (TM), and p-/t-endothelial nitric oxide synthase (eNOS) expressions as well as NO generation and decreased vascular tone. Hence, crocin improved mitochondrial dysfunction through inhibiting ROS-induced KCa3.1 overexpression in the endothelium, which in turn reduced more ROS generation and final endothelial dysfunction in diabetes.

Determinants of self-rated health among an older Tibetan population in a Chinese plateau area: analysis based on the conceptual framework for determinants of health.

BACKGROUND: Self-rated health (SRH) has been frequently used in population health surveys. However, most of these studies only focus on specific factors that might directly affect SRH, so only partial or confounding information about the determinants of SRH is potentially obtained. Conducted in an older Tibetan population in a Chinese plateau area, the aim of our study is to assess interrelationships between various factors affecting SRH based on the conceptual framework for determinants of health. METHODS: Between May 2018 and September 2019, 2707 Tibetans aged 50 years or older were recruited as part of the China Multi-Ethnic Cohort Study (CMEC) from the Chengguan District of Lhasa city in Tibet. The information included SRH and variables based on the conceptual framework for determinants of health (i.e., socioeconomic status, health behaviors, physical health, mental health, and chronic diseases). Structural equation modeling (SEM) was used to estimate the direct and indirect effects of multiple factors in the conceptual framework. RESULTS: Among all participants, 5.54% rated their health excellent, 51.16% very good, 33.58% good, 9.12% fairly poor and 0.59% poor. Physical health (ß = - 0.23, P <  0.001), health behaviors (ß = - 0.44, P <  0.001), socioeconomic status (ß = - 0.29, P <  0.001), chronic diseases (ß = - 0.32, P <  0.001) and gender (ß = 0.19, P <  0.001) were directly associated with SRH. Socioeconomic status, physical health and gender affected SRH both directly and indirectly. In addition, there are potential complete mediator effects in which age and mental health affect SRH through mediators, such as physical health, health behaviors and chronic diseases. CONCLUSIONS: The findings suggested that interventions targeting behavioral changes, health and chronic disease management should be attached to improve SRH among older populations in plateau areas without ignoring gender and socioeconomic disparities.