[Analysis of the relationship between high altitude polycythemia and peptic ulcer bleeding]

To explore the relationship between high altitude polycythemia (HAPC) and peptic ulcer bleeding, in order to provide the evidence for the clinical diagnosis and treatment of peptic ulcer disease in Tibet of China.

A retrospective case-control study was conducted. Patients who hospitalized in the Department of Gastroenterology with the diagnosis of peptic ulcer bleeding from January 1, 2015 to April 30, 2021 in Tibet Autonomous Region People's Hospital were enrolled in the case group, and patients who hospitalized in the Department of Urology without tumor and without the history of peptic ulcer and gastrointestinal bleeding during the same period were selected as the control group. In the study, 1 ∶ 1 case matching was conducted between the two groups according to the gender, age (±2 years), ethnic group (Tibetan, Han), and the residence altitude level (grouped by < 4 000 m or ≥4 000 m), and 393 cases were included in the case group and the control group respectively. All the patients had lived in Tibet with the altitude >2 500 m for more than 1 year, and with age ≥ 18 years. The risk factors of peptic ulcer bleeding (place of residence, smoking, alcohol, the use of NSAIDs/anticoagulants, and combined with chronic diseases, such as HAPC, hypertension, diabetes mellitus, heart disease, hyperlipidemia, cerebrovascular disease, chronic lung disease, joint disease) were analyzed and compared between the two groups.

There were 28 (7.1%) patients with HAPC in the case group, and 5 (1.3%) in the control group. The incidence of HAPC in the case group was significantly higher than those in the control group, P < 0.001, and the OR value was 5.953. Multivariate Logistic regression analysis showed that HAPC (OR=5.270, 95%CI: 1.806-15.380), living in cities and towns (OR=2.369, 95%CI: 1.559-3.602), alcohol (OR=3.238, 95%CI: 1.973-5.317) and the use of NSAIDs/anticoagulants (OR=20.584, 95%CI: 2.639-160.545) were the independent risk factors for peptic ulcer bleeding in Tibet. After adjusting for the possible confounding factors, such as living in cities and towns, alcohol, and the use of NSAIDs/anticoagulants, HAPC was associated with an increased risk of peptic ulcer bleeding in Tibet, and the OR value was 5.270.

HAPC was associated with a significantly increased risk of peptic ulcer bleeding in Tibet. Patients with HAPC and peptic ulcer should be diagnosed and treated actively, in order to avoid gastrointestinal bleeding and other serious complications.