Background: Preserved ratio impaired spirometry (PRISm) has been associated with adverse outcomes and increased transition to other spirometric categories over time. We aimed to examine its prevalence, trajectories over time, and outcomes in a population-based sample from Latin America. Methods: Data were obtained from two population-based surveys of adults from three cities in Latin America (PLATINO study), conducted on the same individuals 5– 9 years after their baseline examination. We estimated the frequency of PRISm defined by FEV₁/FVC≥ 0.70 with FEV₁ < 80%, describing their clinical characteristics, longitudinal transition trajectories over time, factors associated with the transition. Results: At baseline, 2942 participants completed post-bronchodilator spirometry, and 2026 at both evaluations. The prevalence of normal spirometry was 78%, GOLD-stage 1 10.6%, GOLD 2– 4 6.5%, and PRISm was: 5.0% (95% CI 4.2– 5.8). PRISm was associated with less schooling, more reports of physician-diagnosis of COPD, wheezing, dyspnea, missing days at work, having ≥ 2 exacerbations in the previous year but without accelerated lung function decline. Mortality risk was significantly higher in PRISm (HR 1.97, 95% CI 1.2– 3.3) and COPD GOLD 1– 4 categories (HR 1.79, 95% CI 1.3– 2.4) compared with normal spirometry. PRISm at baseline most frequently transitioned to another category at follow-up (46.5%); 26.7% to normal spirometry and 19.8% to COPD. The best predictors of transition to COPD were closeness of FEV₁/FVC to 0.70, older age, current smoking, and a longer FET in the second assessment. Conclusion: PRISm, is a heterogeneous and unstable condition prone to adverse outcomes that require adequate follow-up.

Introduction: The novel coronavirus pandemic (COVID–19) represents a major public health problem and it is key to find a treatment that reduces mortality. Our objective was to estimate whether treatment with 400 mg/day of Hydroxychloroquine for 10 days reduces in-hospital mortality in subjects with severe respiratory disease due to COVID-19 compared with placebo.Material and methods: A double-blind, randomized, placebo-controlled trial to evaluate the safety and efficacy of Hydroxychloroquine for the treatment of severe disease by COVID-19 through an intention-to-treat analysis. Eligible for the study were adults aged more than 18 years with COVID-19 confirmed by RT-PCR and lung injury requiring hospitalization with or without mechanical ventilation. Primary outcome was 30-day mortality. Secondary outcomes: days of mechanical ventilation, days of hospitalization and cumulative incidence of serious adverse events.Results: A total of 214 patients with COVID-19 were recruited, randomized and analyzed. They were hypoxemic with a mean SpO₂of 65% ± 20, tachycardic (pulse rate 108±17 min-¹) and tachypneic (32 ±10 min-¹); 162 were under mechanical ventilation at randomization. Thirty-day mortality was similar in both groups (38% in Hydroxychloroquine vs. 41% in placebo, hazard ratio [HR] 0.88, 95% Confidence Interval [95%CI] 0.51–1.53). In the surviving participants, no significant difference was found in secondary outcomes.Conclusion: No beneficial effect or significant harm could be demonstrated in our randomized controlled trial including 214 patients, using relatively low doses of Hydroxychloroquine compared with placebo in hospitalized patients with severe COVID-19.

During the first year of the COVID-19 pandemic, various authors reported that acute exacerbations of COPD (AECOPD) were reduced [1–4]. In Mexico City, during the beginning of the pandemic, a voluntary lockdown was declared and therefore the adherence to health measures was more flexible and less stringent in the general population than in other countries [5]. However, because there was a reduction of exposure to air pollutants such as particulate matter with a diameter <10 μm (PM₁₀) and <2.5 µm (PM_2.5), as well as total suspended particles levels during the first year of the pandemic, especially among patients living in urban areas like Mexico City, AECOPD could be diminished as other countries have reported [1–4].

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.

Background: Phase III clinical trials have documented the efficacy of the SARS-CoV-2 vaccines in preventing symptomatic COVID-19. Nonetheless, it is imperative to continue analyzing the clinical response to different vaccines in real-life studies. Our objective was to evaluate the effectiveness of five different vaccines in hospitalized patients with COVID-19 during the third COVID-19 outbreak in Mexico dominated by the Delta variant. Methods: A test-negative case–control study was performed in nine tertiary-care hospitals for COVID-19. We estimated odds ratios (OR) adjusted by variables related a priori with the likelihood of SARS-CoV-2 infection and its severity. Results: We studied 761 subjects, 371 cases, and 390 controls with a mean age of 53 years (SD, 17 years). Overall, 51% had a complete vaccination scheme, and an incomplete scheme (one dose from a scheme of two), 14%. After adjustment for age, gender, obesity, and diabetes mellitus, we found that the effectiveness of avoiding a SARS-CoV-2 infection when hospitalized with at least one vaccination dose was 71% (OR 0.29, 95% CI 0.19–0.45), that of an incomplete vaccination scheme, 67% (OR 0.33, 95% CI 0.18–0.62), and that of any complete vaccination scheme, 73% (OR 0.27, 95% CI 0.17–0.43). Conclusions: The SARS-CoV-2 vaccination program showed effectiveness in preventing SARS-CoV-2 infection in hospitalized patients during a Delta variant outbreak.