UNASSIGNED: The study aimed to explore the risk factors for hyperuricemia (HUA) in the Naxi ethnic population residing in high-altitude areas of Yunnan, China, and assess the clinical value of the triglyceride/high-density lipoprotein cholesterol (TG/HDL-c) ratio as a diagnostic marker.
UNASSIGNED: In this cross-sectional study, clinical data were collected from the health checkup population in the People\'s Hospital of Yulong Naxi Autonomous County, Yunnan Province, from January 2021 to January 2023. Participants were divided into quartiles based on the TG/HDL-c ratio (Q1, Q2, Q3, and Q4) for group analysis using chi-square tests, t-tests, and rank sum tests. Logistic regression analysis and linear regression models were employed to further investigate the correlation between the prevalence of hyperuricemia and TG/HDL-c ratio in this high-altitude Naxi population.
UNASSIGNED: A total of 714 participants from the health checkup population were included in the study, of whom 61.5% were male participants and 38.5% were female participants, and the average age was 41.21 ± 11.69 years. The mean uric acid level was 388.51 ± 99.24. After correcting for confounding factors, TG/HDL-c, serum creatinine (Scr), blood urea nitrogen (BUN), triglyceride (TG), high-density lipoprotein cholesterol (HDL-c), red blood cells (RBCs), and hemoglobin (Hb) showed a positive correlation with blood uric acid. Further analysis involved categorizing the TG/HDL-c ratio from a continuous variable to a categorical variable using quartiles. The fully adjusted model showed results that were consistent with the trend observed in the continuous variable analysis when considering the TG/HDL-c ratio as a categorical variable. In addition, in all unadjusted and adjusted models, the serum uric acid (SUA) levels in the high TG/HDL-c ratio group were significantly higher than those in the low TG/HDL-c ratio group (trend p < 0.001). Further linear relationship analysis indicated that after adjusting for covariates, there was an approximate linear relationship between the TG/HDL-c and SUA levels, with a coefficient (β) of 5.421.
UNASSIGNED: The prevalence of hyperuricemia is greater in high-altitude areas of Yunnan, showing a nearly linear positive correlation with the TG/HDL-c ratio. Monitoring TG/HDL-c levels may benefit patients with hyperuricemia.

BACKGROUND: Partial pressure of carbon dioxide (PaCO2) is generally known to influence outcome in patients with traumatic brain injury (TBI) at normal altitudes. Less is known about specific relationships of PaCO2 levels and clinical outcomes at high altitudes.
METHODS: This is a prospective single-center cohort of consecutive patients with TBI admitted to a trauma center located at 2600 m above sea level. An unfavorable outcome was defined as a Glasgow Outcome Scale-Extended (GOSE) score < 4 at the 6-month follow-up.
RESULTS: We had a total of 81 patients with complete data, 80% (65/81) were men, and the median (interquartile range) age was 36 (25-50) years. Median Glasgow Coma Scale (GCS) score on admission was 9 (6-14); 49% (40/81) of patients had severe TBI (GCS 3-8), 32% (26/81) had moderate TBI (GCS 12-9), and 18% (15/81) had mild TBI (GCS 13-15). The median (interquartile range) Abbreviated Injury Score of the head (AISh) was 3 (2-4). The frequency of an unfavorable outcome (GOSE < 4) was 30% (25/81), the median GOSE was 4 (2-5), and the median 6-month mortality rate was 24% (20/81). Comparison between patients with favorable and unfavorable outcomes revealed that those with unfavorable outcome were older, (median age 49 [30-72] vs. 29 [22-41] years, P < 0.01), had lower admission GCS scores (6 [4-8] vs. 13 [8-15], P < 0.01), had higher AISh scores (4 [4-4] vs. 3 [2-4], P < 0.01), had higher Acute Physiology and Chronic Health disease Classification System II scores (17 [15-23] vs. 10 [6-14], P < 0.01), had higher Charlson scores (0 [0-2] vs. 0 [0-0], P < 0.01), and had higher PaCO2 levels (mean 35 ± 8 vs. 32 ± 6 mm Hg, P < 0.01). In a multivariate analysis, age (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.1-1.30, P < 0.01), AISh (OR 4.7, 95% CI 1.55-21.0, P < 0.05), and PaCO2 levels (OR 1.23, 95% CI 1.10-1.53, P < 0.05) were significantly associated with the unfavorable outcomes. When applying the same analysis to the subgroup on mechanical ventilation, AISh (OR 5.4, 95% CI 1.61-28.5, P = 0.017) and PaCO2 levels (OR 1.36, 95% CI 1.13-1.78, P = 0.015) remained significantly associated with the unfavorable outcome.
CONCLUSIONS: Higher PaCO2 levels are associated with an unfavorable outcome in ventilated patients with TBI. These results underscore the importance of PaCO2 levels in patients with TBI and whether it should be adjusted for populations living at higher altitudes.

BACKGROUND: During the last two decades, Caesarean section rates (C-sections), overweight and obesity rates increased in rural Peru. We examined the association between pre-pregnancy body mass index (BMI) and C-section in the province of San Marcos, Northern Andes-Peru.
METHODS: This is a prospective cohort study. Participants were women receiving antenatal care in public health establishments from February 2020 to January 2022, who were recruited and interviewed during pregnancy or shortly after childbirth. They answered a questionnaire, underwent a physical examination and gave access to their antenatal care card information. BMI was calculated using maternal height, measured by the study team and self-reported pre-pregnancy weight measured at the first antenatal care visit. For 348/965 (36%) women, weight information was completed using self-reported data collected during the cohort baseline. Information about birth was obtained from the health centre\'s pregnancy surveillance system. Regression models were used to assess associations between C-section and BMI. Covariates that changed BMI estimates by at least 5% were included in the multivariable model.
RESULTS: This study found that 121/965 (12.5%) women gave birth by C-section. Out of 495 women with pre-pregnancy normal weight, 46 (9.3%) had C-sections. Among the 335 women with pre-pregnancy overweight, 53 (15.5%) underwent C-sections, while 23 (18.5%) of the 124 with pre-pregnancy obesity had C-sections. After adjusting for age, parity, altitude, food and participation in a cash transfer programme pre-pregnancy overweight and obesity increased the odds of C-section by more than 80% (aOR 1.82; 95% CI 1.16-2.87 and aOR 1.85; 95% CI 1.02-3.38) compared to women with a normal BMI.
CONCLUSIONS: High pre-pregnancy BMI is associated with an increased odds of having a C-section. Furthermore, our results suggest that high BMI is a major risk factor for C-section in this population. The effect of obesity on C-section was partially mediated by the development of preeclampsia, suggesting that C-sections are being performed due to medical reasons.

UNASSIGNED: The cardioprotective effect of remote ischemia preconditioning in clinical studies is inconsistent with experimental results. Adaptation to high-altitude hypoxia has been reported to be cardioprotective in animal experiments. However, the clinical significance of the cardioprotective effect of high-altitude adaptation has not been demonstrated.
UNASSIGNED: A retrospective cohort study with propensity score matching was designed to compare the outcomes of cardiac surgery between highlanders and lowlanders in a tertiary teaching hospital. The data of adult cardiac surgical patients from January 2013 to December 2022, were collected for analysis. Patients with cardiopulmonary bypass and cardioplegia were divided into a low-altitude group (<1,500 m) and a high-altitude group (≥1,500 m) based on the altitude of their place of residence.
UNASSIGNED: Of 3,020 patients, the majority (87.5%) permanently lived in low-altitude regions [495 (435, 688) m], and there were 379 patients (12.5%) in the high-altitude group [2,552 (1,862, 3,478) m]. The 377 highlander patients were matched with lowlander patients at a ratio of 1:1. The high-altitude group exhibited a 44.5% reduction in the incidence of major adverse cardiovascular events (MACEs) compared with the low-altitude group (6.6% vs. 11.9%, P = 0.017). The patients in the moderate high-altitude subgroup (2,500-3,500 m) had the lowest incidence (5.6%) of MACEs among the subgroups. The level of creatinine kinase muscle-brain isoenzymes on the first postoperative morning was lower in the high-altitude group than in the low-altitude group (66.5 [47.9, 89.0] U/L vs. 69.5 [49.3, 96.8] U/L, P = 0.003).
UNASSIGNED: High-altitude adaptation exhibits clinically significant cardioprotection in cardiac surgical patients.

UNASSIGNED: Research on the association between sugar-sweetened beverages (SSBs) consumption and sleep quality with anxiety symptoms has been highly emphasized. However, past studies have focused on college students in plains areas, while fewer research studies have been conducted on Tibetan college students at high altitudes. Whether this association changes due to ethnicity or altitude is unclear. The present study will contribute to the prevention and intervention of depressive symptoms among Tibetan college students at high altitude.
UNASSIGNED: A self-assessment questionnaire was administered to 3,026 university students (1,491 boys students, 49.27%) on SSBs consumption, sleep quality and anxiety symptoms status in the Tibetan Plateau, a high-altitude region of China. Logistic regression analysis and ordered logistic regression analysis in generalized linear model were used to analyze the association between SSBs consumption and sleep quality with anxiety symptoms.
UNASSIGNED: The prevalence of anxiety symptoms among Tibetan college students at high altitude was 26.9%. SSBs consumption of ≤1 times/week, 2-5 times/week, and ≥ 6 times/week were 20.7, 28.1, and 45.7%, respectively, with statistically significant differences (χ2 value of 134.353, p < 0.001). Anxiety detection rates for Sleep quality of Good (PSQI ≤5), Moderate (PSQI 6-7), and Poor (PSQI >7) were 16.8, 19.8, and 32.0%, respectively, and the difference was also statistically significant (χ2 value was 73.761, p < 0.001). The ordered logistic regression analysis in the generalized linear model showed that, overall, the group of college students with SSBs ≤1 times/week and sleep quality of Good served as the reference group, and the group with SSBs ≥6 times/week and sleep quality of Poor (OR: 5.06, 95% CI: 3.75-6.83) had the highest risk of anxiety symptoms.
UNASSIGNED: SSBs consumption and sleep quality were associated with anxiety symptoms, and there was an interaction effect. Effective control of SSBs consumption and improvement of sleep quality may be important factors in preventing and reducing the occurrence of anxiety symptoms.

BACKGROUND: The Global Campaign against Headache is conducting a series of population-based studies to fill the large geographical gaps in knowledge of headache prevalence and attributable burden. One major region not until now included is South America. Here we present a study from Peru, a country of 32.4 million inhabitants located at the west coast of South America, notable for its high Andes mountains.
METHODS: The study was conducted in accordance with the standardized methodology used by the Global Campaign. It was a cross-sectional survey using cluster randomised sampling in five regions to derive a nationally representative sample, visiting households unannounced, and interviewing one randomly selected adult member (aged 18-65 years) of each using the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire translated into South American Spanish. The neutral screening question (\"Have you had headache in the last year?\") was followed by diagnostic questions based on ICHD-3 and demographic enquiry.
RESULTS: The study included 2,149 participants from 2,385 eligible households (participating proportion 90.1%): 1,065 males and 1,084 females, mean age 42.0 ± 13.7 years. The observed 1-year prevalence of all headache was 64.6% [95% CI: 62.5-66.6], with age-, gender- and habitation-adjusted prevalences of 22.8% [21.0-24.6] for migraine (definite + probable), 38.9% [36.8-41.0] for tension-type headache (TTH: also definite + probable), 1.2% [0.8-1.8] for probable medication-overuse headache (pMOH) and 2.7% [2.1-3.5] for other headache on ≥ 15 days/month (H15+). One-day prevalence of headache (reported headache yesterday) was 12.1%. Migraine was almost twice as prevalent among females (28.2%) as males (16.4%; aOR = 2.1; p < 0.001), and strongly associated with living at very high altitude (aOR = 2.5 for > 3,500 versus < 350 m).
CONCLUSIONS: The Global Campaign\'s first population-based study in South America found headache disorders to be common in Peru, with prevalence estimates for both migraine and TTH substantially exceeding global estimates. H15 + was also common, but with fewer than one third of cases diagnosed as pMOH. The association between migraine and altitude was confirmed, and found to be strengthened at very high altitude. This association demands further study.

Research on the outdoor thermal comfort (OTC) of a university campus is beneficial to the physical and mental health of college students.
In this study, the OTC of students attending Tibet University in Lhasa, which experiences high-altitude cold climate conditions, under different activity intensities was studied using field measurements and a questionnaire survey.
With the increase in activity intensity, the comfort physiologically equivalent temperature (PET) value gradually increased in summer, while the comfortable PET value gradually decreased in winter. The most comfortable PET value is 17.6°C in summer and 11.5°C in winter. The neutral PET of Tibetan college students during outdoor activities in summer was 16.3°C, and the neutral PET of outdoor activities in winter was 12.1°C. Gender and ethnicity had different effects on thermal sensation under different activity intensities. Under vigorous-intensity activities, PET in winter and summer had the greatest influence on thermal sensation. The situation was different under moderate-intensity activity. PET had the greatest influence on thermal sensation in summer, and Tmrt had the greatest influence on thermal sensation in winter.
These findings provide a basis for an improved design of the outdoor environment under different outdoor activity intensities in high-altitude areas.

González-García, Mauricio and Luis Ernesto Téllez. Adaptation to living at high altitude in patients with COPD. Comparative study of exercise capacity and ventilatory variables between patients residing at high and low altitudes in the Andes. High Alt Med Biol. 00:000-000, 2024. Introduction: Although some variables related to oxygen transport and utilization such as ventilation, pulmonary vascular responses to hypoxia, heart rate (HR), cardiac output, hemoglobin (Hb), and oxygen saturation (SpO2) are used to compare adaptation to altitude between populations, peak oxygen consumption (VO2) constitutes an integrative measure of total oxygen transport that may reflect successful adaptation to altitude. We designed this study to make a direct comparison of VO2 in a cardiopulmonary exercise test (CPET) between chronic obstructive pulmonary disease (COPD) patients residing at high altitude (Bogotá, Colombia: 2,640 m) (COPD-HA) and those living at low altitude (Bucaramanga, Colombia: 959 m) (COPD-LA). Methods: All patients performed a CPET with measurements of VO2, minute ventilation (VE), HR, oxygen pulse (VO2/HR), ventilatory equivalents (VE/VCO2), and SpO2. Unpaired T-test or Mann-Whitney U test were used for comparisons between COPD-HA and COPD-LA. Results: We included 71 patients with COPD, 53 COPD-HA, and 18 COPD-LA. There were no differences between groups in age, sex, or forced expiratory volume in 1 second. The means ± SD of Hb, g/dl was slightly higher in COPD-HA (15.9 ± 1.9 vs. 14.7 ± 1.8, p = 0.048), without differences in VO2, % pred (71.6 ± 17.9 vs. 69.0 ± 17.0, p = 0.584), VO2/HR, % pred (92.1 ± 22.0 vs. 89.7 ± 19.8, p = 0.733) or VE/MVV, % (75.5 ± 14.1 vs. 76.5 ± 14.3, p = 0.790) at peak exercise between groups. Median (IQR) of VE/VCO2 nadir [38.0 (37.0-42.0) vs. 32.5 (31.0-39.0), p = 0.005] was significantly higher, and SpO2, % at rest [88.0 (86.0-91.0) vs. 95.0 (94.0-96.0), p < 0.001] and at peak exercise [84.0 (77.0-90.0) vs. 93.0 (92.0-95.0), p < 0.001] were significantly lower in COPD-HA. Conclusions: Despite higher desaturation at rest and during exercise in COPD-HA, there were no differences in VO2 peak between COPD-HA and COPD-LA, suggesting a potential altitude adaptation in those patients chronically exposed to hypoxia.

UNASSIGNED: Prolonged exposure to hypoxia at high altitudes can affect the eyes through various mechanisms, culminating in reduced vision. Multiple studies on this subject have focused on the ocular effects of high altitude on intraocular pressure (IOP), corneal thickness, and the retina. However, there is a lack of literature on the effects of \'moderate high altitude (2000-3000 m)\' on the eyes. Hence, we designed our study to determine the impact of moderate high altitude on the eyes.
UNASSIGNED: We recruited two age and gender-matched groups of 250 research participants, each at moderate high altitude (Group A) and plains (Group B), respectively, to determine the effects of moderate high altitude on ocular health, if any.
UNASSIGNED: We found a statistically significant increase in dry eye in Group A. We also found four cases of central serous retinopathy and one case of central retinal vein occlusion in Group A. There was no statistically significant change in visual acuity, IOP, or central corneal thickness.
UNASSIGNED: There is a vast lacuna in the literature on this particular altitude range, and further studies are required to confirm our findings. It is also recommended that lubricant eye drops be advised as a standard prophylactic measure for all individuals traveling and staying at moderate high altitude.

UNASSIGNED: partial pressure of carbon dioxide (PaCO2) is generally known to influence outcome in patients with traumatic brain injury (TBI) at normal altitudes. Less is known about specific relationships of PaCO2 levels and clinical outcomes at high altitudes.
UNASSIGNED: This is a prospective single-center cohort of consecutive TBI patients admitted to a trauma center located at 2600 meter above sea level. An unfavorable outcome was defined as the Glasgow Outcome Scale-Extended (GOSE) < 4 at 6-month follow-up.
UNASSIGNED: 81 patients with complete data, 80% (65/81) were men, and median (IQR) age was 36 (25-50) years). Median Glasgow Coma Scale (GCS) on admission was 9 (6-14), 49% (40/81) were severe (GCS: 3-8), 32% (26/81) moderate (GCS 12 - 9), and 18% (15/81) mild (GCS 13-15) TBI. The median (IQR) Abbreviated Injury Score of the Head (AISh) was 3 (2-4). Frequency of an unfavorable outcome (GOSE < 4) was 30% (25/81), median GOSE was 4 (2-5), and 6-month mortality was 24% (20/81). Comparison between patients with favorable and unfavorable outcomes revealed that those with unfavorable outcome were older, median [49 (30-72) vs. 29 (22-41), P < 0.01], had lower admission GCS [6 (4-8) vs. 13 (8-15), P < 0.01], higher AIS head [4 (4-4) vs. 3(2-4), p < 0.01], higher APACHE II score [17(15-23) vs 10 (6-14), < 0.01), higher Charlson score [0(0-2) vs. 0 (0-0), P < 0.01] and higher PaCO2 (mmHg), mean ± SD, 39 ± 9 vs. 32 ± 6, P < 0.01. In a multivariate analysis, age (OR 1.14 95% CI 1.1-1.30, P < 0.01), AISh (OR 4.7 95% CI 1.55-21.0, P < 0.05), and PaCO2 (OR 1.23 95% CI: 1.10-1.53, P < 0.05) were significantly associated with the unfavorable outcomes. When applying the same analysis to the subgroup on mechanical ventilation, AISh (OR 5.4 95% CI: 1.61-28.5, P = 0.017) and PaCO2 (OR 1.36 95% CI: 1.13-1.78, P = 0.015) remained significantly associated with the unfavorable outcome.
UNASSIGNED: Higher PaCO2 levels are associated with an unfavorable outcome in ventilated TBI patients. These results underscore the importance of PaCO2 level in TBI patients and whether it should be adjusted for populations living at higher altitudes.