To systematically summarize the risk factors for hypoxemia and related adverse events in older patients undergoing gastrointestinal endoscopy under sedation or anesthesia, and to provide evidence for preprocedural risk stratification and perioperative prevention.

A systematic review was conducted in accordance with PRISMA 2020. PubMed, Web of Science, Cochrane Library, Embase, CINAHL, and major Chinese databases were searched from inception to August 23, 2026. Observational studies reporting extractable data on risk factors were included. Study quality was assessed using the Newcastle-Ottawa Scale (NOS), and meta-analysis was performed with RevMan 5.3.

Ten studies involving a total of 8, 284 participants were included, with NOS scores ranging from 7 to 9. Pooled analyses showed that advanced age (OR=2.99), higher body mass index (BMI; OR=3.54), hypertension (OR=1.73), a history of smoking (OR=2.58), and a history of alcohol consumption (OR=1.41) were associated with an increased risk of the outcome. Pulmonary disease/chronic obstructive pulmonary disease (COPD; RR=2.41), a history of snoring (OR=3.53), and higher American Society of Anesthesiologists (ASA) physical status (OR=3.11) were also significantly associated with increased risk. Sex (OR=1.17, P=0.07) and diabetes mellitus (random-effects OR=1.30, P=0.16) were not significantly associated with the outcome.

Current evidence suggests that advanced age, higher BMI, a history of snoring, hypertension, smoking, alcohol consumption, pulmonary disease/COPD, and higher ASA physical status may increase the risk of hypoxemia or related adverse events during gastrointestinal endoscopy under sedation or anesthesia in older patients. These factors should be considered in preprocedural assessment and individualized oxygenation and airway-management strategies. Because some included studies used composite adverse-event outcomes and several risk factors showed substantial heterogeneity, these findings require further confirmation in high-quality prospective studies.