Hematological Characteristics, Oxidative Stress, and Patient-Reported Symptoms in Tibetan Patients with Chronic Mountain Sickness at 4500m Altitude

Yang Zhong¹Fengying Zhang¹Qiuyue Li¹Doudou Hao¹Zhiyou Shi²Yuling Liu²Suying Zhu²Pasang Tsering³Yunhong Wu^1*

• ¹Hospital of Chengdu Office of People's Government of Xizang Autonomous Region (Hospital.C.X.), Chengdu, China
• ²Medicine College of Tibet University, Lhasa, China
• ³Tibetan Hospital of Nagqu, Nagqu, China

Background Chronic mountain sickness (CMS), driven by chronic hypoxia, features erythrocytosis, cardiovascular impairment, and systemic oxidative stress. Current studies focus on haematological and cardiopulmonary changes, but multidimensional features like sleep disturbances, quality of life, and oxidative stress remain underexplored. Methods The cross-sectional study included 47 adult Tibetan residents living at 4,500 metres and diagnosed with CMS using Qinghai criteria. Blood samples were collected, and questionnaires assessed quality of life, fatigue, and sleep. Multivariate logistic regression was used to explore associations between variables, using CMS comorbid with high-altitude polycythemia (HAPC) or sleep disturbance as endpoints. Results The mean age of patients was 40.57 ± 6.21 years (29 males, 18 females). Males had higher RBC, HGB, HCT, UA, and T-AOC levels (all P < 0.001). A moderate to strong positive correlation was observed between these markers. 91.67% of patients with comorbid HAPC were males with severe CMS. Lower MCHC (OR = 0.80, P = 0.02) and higher T-AOC (OR = 1.47, P = 0.02) were associated with HAPC. Males (OR = 0.11, P = 0.03), higher 8-OHdG levels (OR = 0.95, P = 0.03), higher body pain scores (OR = 0.91, P < 0.01), and higher general health scores (OR = 0.90, P = 0.02) were more likely to report good sleep quality. Conclusion Males with CMS had higher T-AOC and better sleep quality than females. Good sleep quality was associated with better quality of life and less fatigue. Oxidative stress indicators correlated with clinical phenotypes, but causality requires further investigation. This trial was registered at Chinese Clinical Trial Registry (ChiCTR2400082685).