Blood endotoxin levels as biomarker of non-alcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND AND AIMS: Growing evidence supports a role of gut-derived metabolites in non-alcoholic fatty liver disease (NAFLD), but the relation of endotoxin levels with gut permeability and NAFLD stage remains unclear. This systematic review with meta-analysis aims to provide further insights. METHODS: PubMed, Embase and Cochrane Library were searched for studies published until January 2022 assessing blood endotoxins in patients with NAFLD. Meta-analyses, univariate/multivariate meta-regression as well as correlation analyses were performed for endotoxin values and potential relationships to disease stage, age, sex, parameters of systemic inflammation, metabolic syndrome as well as liver function and histology. RESULTS: 43 studies were included, of which 34 for meta-analyses. Blood endotoxin levels were higher in simple steatosis patients vs. liver-healthy controls (SMD=0.86, CI=0.62-1.11) as well as in NASH vs. NAFL/non-NASH patients (SMD=0.81, CI=0.27-1.35, P=.0078). Consistently, higher endotoxin levels were observed in patients with more advanced histopathological gradings of liver steatosis and fibrosis. An increase of blood endotoxin levels was partially attributed to a BMI-rise in NAFLD patients compared to controls. Nevertheless, significant increases of blood endotoxin levels in NAFLD retained after compensation for differences in BMI, metabolic condition or liver enzymes. Increases in blood endotoxin levels were associated with increases in CRP concentrations and in most cases paralleled a rise in markers for intestinal permeability. CONCLUSION: Our results support blood endotoxin levels as relevant diagnostic biomarker for NAFLD, both for disease detection as well as staging during disease progression, and might serve as surrogate marker of enhanced intestinal permeability in NAFLD

Cardiovascular Risk Profiles and Pre-Existing Health Conditions of Trekkers in the Solu-Khumbu Region, Nepal

Background: High-altitude tourist trekking continues to grow in popularity on the Everest Trek in Nepal. We examined which pre-existing cardiovascular and health conditions these global trekkers had and what health issues they encountered during the trek, be it exacerbations of pre-existing conditions, or new acute ones. Method: Trekkers (n = 350) were recruited from guesthouses along the Everest Trek, mostly at Tengboche (3860 m). After completing a questionnaire on their health and travel preparation, they underwent a basic physical examination with an interview. Results: Almost half (45%) had pre-existing conditions, mostly orthopaedic and cardiovascular diseases. The average age was 42.7 years (range 18–76). The average BMI was 23.4 kg/m2, but 21% were overweight. A third were smokers (30%), and 86% had at least one major cardiovascular risk factor. A quarter (25%) were suffering from manifest acute mountain sickness (AMS), and 72% had at least one symptom of AMS. Adequate pre-travel examination, consultation, and sufficient personal preparation were rarely found. In some cases, a distinct cardiovascular risk profile was assessed. Hypertensive patients showed moderately elevated blood pressure, and cholesterol levels were favourable in most cases. No cardiovascular emergencies were found, which was fortunate as timely, sufficient care was not available during the trek. Conclusion: The results of earlier studies in the Annapurna region should be revalidated. Every trekker to the Himalayas should consult a physician prior to departure, ideally a travel medicine specialist. Preventative measures and education on AMS warrant special attention. Travellers with heart disease or with a pronounced cardiovascular risk profile should be presented to an internal medicine professional. Travel plans must be adjusted individually, especially with respect to adequate acclimatisation time and no physical overloading. With these and other precautions, trekking at high altitudes is generally safe and possible, even with significant pre-existing health conditions. Trekking can lead to invaluable personal experiences. Since organized groups are limited in their flexibility to change their itinerary, individual trekking or guided tours in small groups should be preferred