Grigorios I. Leontiadis

Transgression of planetary boundaries, such as biosphere integrity, climate change, and the introduction of new entities like microplastics, may have detrimental effects on human health. Health sys... Human health and natural systems are intrinsically linked—stable natural systems enable healthy human life. Health systems aim to promote, restore, and maintain health. Health systems may promote h...

Health systems contribute to environmental degradation while simultaneously being affected by its consequences. Yet, planetary health considerations are largely absent from health guidelines. On November 6–7, 2024, the Planetary Health Expert Workshop convened over 50 experts from the GRADE Planetary Health Project Group at Humanitas University, Italy, to explore methods for embedding planetary health into health guideline development. Through presentations, case studies, and group discussions, participants identified key methodological gaps and proposed processes and tools to advance the integration of planetary health in health guidelines. Case studies highlighted the need to balance clinical effectiveness with long‐term planetary impacts. This workshop demonstrates a strong interest in integrating planetary health considerations into health guidelines, ensuring evidence‐based health recommendations are not only effective for individuals but also reduce planetary boundary transgressions, restoring Earth's natural systems.

Introduction: Individual human health is inextricably linked to planetary health, which refers to the health of human civilization and the natural systems on which it depends. These systems are captured by the nine planetary boundaries which together define a safe operating space for humanity. The health sector contributes to the transgression of these boundaries, thereby jeopardizing both individual and planetary health. However, there is a growing interest in the health sector in incorporating the preservation of planetary boundaries into health guidelines and health technology assessments (HTAs), which synthesize evidence and guide healthcare decisions. Methods: This scoping review aims to describe methodological guidance and considerations for incorporating planetary health in health guidelines and HTAs. We conducted a scoping review adhering to the JBI methodology including articles from several databases since inception until September 2023. We used narrative synthesis and descriptive statistics to describe eligible studies. Results: Of the 38 included studies, 14 (37%) were commentaries, six (16%) were methodological papers, and four (10·5%) were health guidelines. Included studies focused primarily on greenhouse gas emissions as an outcome. The included health guidelines were rated at a median of 52% (range: 16% to 67%) on AGREE II for methodological quality. Discussion: Key findings pertain to the normative significance of planetary health in guidelines and HTAs, scope and quality of included studies, inconsistencies in methods, and challenges in implementation. These findings will inform future Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) guidance on planetary health. Registration: A protocol of this scoping review was registered in Open Science Framework ( https://osf.io/3jmsa ) and published in the journal Systematic Reviews (10.1186/s13643‐024‐02577‐2).

Telemedicine is increasingly common in gastroenterology and may represent an opportunity for improving sustainability in medical care. The purpose of this study was to determine the carbon emissions related to travel for in-person gastroenterology clinic appointments. We conducted a cross-sectional analysis evaluating carbon emissions associated with travel to gastroenterology appointments over a 2-week period. We determined the average number of appointments per day and used patient’s postal codes to estimate travel distances. We estimated carbon emissions based on these travel distances and completed sensitivity analyses to model methods for emissions reductions. We assessed 975 clinic appointments, of which 71 were excluded (eg, insufficient data, non-physician appointments), leaving 904 included appointments of which 75% were follow-up (678) and the remainder were new consultations (226). Sixteen different gastroenterologists had an average of 22.7 patients per clinic. The mean return distance travelled per appointment was 57.3 km which translates to 14.9 kg CO₂ per patient visit. An average day at our clinic was equal to burning 146.6 L of gasoline or the annual carbon capture of 15.5 trees. By changing follow-up appointments or those with a travel distance over 100 km to telehealth, emissions were reduced by 77%. We demonstrate that a relatively modest change in the number of in-person visits can save thousands of litres of gasoline emissions annually from each practicing clinician. While we cannot avoid emissions related to travel for procedure-based appointments, the use of telemedicine is one potential strategy to reduce healthcare-related emissions.

We conducted systematic reviews of predefined clinical questions and used the Grading of Recommendations, Assessment, Development and Evaluations approach to develop recommendations for the periendoscopic management of anticoagulant and antiplatelet drugs during acute gastrointestinal (GI) bleeding and the elective endoscopic setting. The following recommendations target patients presenting with acute GI bleeding: For patients on warfarin, we suggest against giving fresh frozen plasma or vitamin K; if needed, we suggest prothrombin complex concentrate (PCC) compared with fresh frozen plasma administration; for patients on direct oral anticoagulants (DOACs), we suggest against PCC administration; if on dabigatran, we suggest against the administration of idarucizumab, and if on rivaroxaban or apixaban, we suggest against andexanet alfa administration; for patients on antiplatelet agents, we suggest against platelet transfusions; and for patients on cardiac acetylsalicylic acid (ASA) for secondary prevention, we suggest against holding it, but if the ASA has been interrupted, we suggest resumption on the day hemostasis is endoscopically confirmed. The following recommendations target patients in the elective (planned) endoscopy setting: For patients on warfarin, we suggest continuation as opposed to temporary interruption (1–7 days), but if it is held for procedures with high risk of GI bleeding, we suggest against bridging anticoagulation unless the patient has a mechanical heart valve; for patients on DOACs, we suggest temporarily interrupting rather than continuing these; for patients on dual antiplatelet therapy for secondary prevention, we suggest temporary interruption of the P2Y₁₂ receptor inhibitor while continuing ASA; and if on cardiac ASA monotherapy for secondary prevention, we suggest against its interruption. Evidence was insufficient in the following settings to permit recommendations. With acute GI bleeding in patients on warfarin, we could not recommend for or against PCC administration when compared with placebo. In the elective periprocedural endoscopy setting, we could not recommend for or against temporary interruption of the P2Y₁₂ receptor inhibitor for patients on a single P2Y₁₂ inhibiting agent. We were also unable to make a recommendation regarding same-day resumption of the drug vs 1–7 days after the procedure among patients prescribed anticoagulants (warfarin or DOACs) or P2Y₁₂ receptor inhibitor drugs because of insufficient evidence.

Many clinicians have suboptimal knowledge of evolutionary medicine. This discipline integrates social and basic sciences, epidemiology, and clinical medicine, providing explanations, especially ultimate causes, for many conditions. Principles include genetic variation from population bottleneck and founder effects, evolutionary trade-offs, and coevolution. For example, host–microbe coevolution contributes to the inflammatory and carcinogenic variability of Helicobacter pylori. Antibiotic-resistant strains are evolving, but future therapy could target promutagenic proteins. Ancient humans practicing dairying achieved survival and reproduction advantages of postweaning lactase persistence and passed this trait to modern descendants, delegitimizing lactose intolerance as “disease” in people with lactase nonpersistence. Three evolutionary hypotheses are each relevant to multiple diseases: (i) the polyvagal hypothesis posits that prehistoric adaptation of autonomic nervous system reactions to stress is beneficial acutely but, when continued chronically, predisposes individuals to painful functional gastrointestinal disorders, in whom it may be a biomarker; (ii) the thrifty gene hypothesis proposes genetic adaptation to feast–famine cycles among Pleistocene migrants to America, which is mismatched with Indigenous Americans' current diet and physical activity, predisposing them to obesity, nonalcoholic fatty liver disease, and gallstones and their complications; and (iii) the hygiene hypothesis proposes alteration of the gut microbiome, with which humans have coevolved, in allergic and autoimmune disease pathogenesis; for example, association of microbiome-altering proton pump inhibitor use with pediatric eosinophilic esophagitis, early-life gastrointestinal infection with celiac disease, and infant antibiotic use and an economically advanced environment with inflammatory bowel disease. Evolutionary perspectives broaden physicians' understanding of disease processes, improve care, and stimulate research.

Background Upper gastrointestinal (GI) bleeding is a common reason for emergency hospital admission. Proton pump inhibitors (PPIs) reduce gastric acid production and are used to manage upper GI bleeding. However, there is conflicting evidence regarding the clinical efficacy of proton pump inhibitors initiated before endoscopy in people with upper gastrointestinal bleeding. Objectives To assess the effects of PPI treatment initiated prior to endoscopy in people with acute upper GI bleeding. Search methods We searched the CENTRAL, MEDLINE, Embase and CINAHL databases and major conference proceedings to October 2008, for the previous versions of this review, and in April 2018, October 2019, and 3 June 2021 for this update. We also contacted experts in the field and searched trial registries and references of trials for any additional trials. Selection criteria We selected randomised controlled trials (RCTs) that compared treatment with a PPI (oral or intravenous) versus control treatment with either placebo, histamine‐2 receptor antagonist (H₂RA) or no treatment, prior to endoscopy in hospitalised people with uninvestigated upper GI bleeding. Data collection and analysis At least two review authors independently assessed study eligibility, extracted study data and assessed risk of bias. Outcomes assessed at 30 days were: mortality (our primary outcome), rebleeding, surgery, high‐risk stigmata of recent haemorrhage (active bleeding, non‐bleeding visible vessel or adherent clot) at index endoscopy, endoscopic haemostatic treatment at index endoscopy, time to discharge, blood transfusion requirements and adverse effects. We used standard methodological procedures expected by Cochrane. Main results We included six RCTs comprising 2223 participants. No new studies have been published after the literature search performed in 2008 for the previous version of this review. Of the included studies, we considered one to be at low risk of bias, two to be at unclear risk of bias, and three at high risk of bias. Our meta‐analyses suggest that pre‐endoscopic PPI use may not reduce mortality (OR 1.14, 95% CI 0.76 to 1.70; 5 studies; low‐certainty evidence), and may reduce rebleeding (OR 0.81, 95% CI 0.62 to 1.06; 5 studies; low‐certainty evidence). In addition, pre‐endoscopic PPI use may not reduce the need for surgery (OR 0.91, 95% CI 0.65 to 1.26; 6 studies; low‐certainty evidence), and may not reduce the proportion of participants with high‐risk stigmata of recent haemorrhage at index endoscopy (OR 0.80, 95% CI 0.52 to 1.21; 4 studies; low‐certainty evidence). Pre‐endoscopic PPI use likely reduces the need for endoscopic haemostatic treatment at index endoscopy (OR 0.68, 95% CI 0.50 to 0.93; 3 studies; moderate‐certainty evidence). There were insufficient data to determine the effect of pre‐endoscopic PPI use on blood transfusions (2 studies; meta‐analysis not possible; very low‐certainty evidence) and time to discharge (1 study; very low‐certainty evidence). There was no substantial heterogeneity amongst trials in any analysis. Authors' conclusions There is moderate‐certainty evidence that PPI treatment initiated before endoscopy for upper GI bleeding likely reduces the requirement for endoscopic haemostatic treatment at index endoscopy. However, there is insufficient evidence to conclude whether pre‐endoscopic PPI treatment increases, reduces or has no effect on other clinical outcomes, including mortality, rebleeding and need for surgery. Further well‐designed RCTs that conform to current standards for endoscopic haemostatic treatment and appropriate co‐interventions, and that ensure high‐dose PPIs are only given to people who received endoscopic haemostatic treatment, regardless of initial randomisation, are warranted. However, as it may be unrealistic to achieve the optimal information size, pragmatic multicentre trials may provide valuable evidence on this topic.