Heart rate and cholesterol: Exploration of potential risk indicators and screening significance for retinal vascular abnormalities in non-Tibetan young men residing at high altitudes for 1.5 years

To explore the impact of living at high altitudes for 1.5 years on the retinal blood vessels among healthy non-Tibetan young males and to screen related hematological and physiological indicators, providing a basis for increasing the eye examination items in high-altitude regions.

A cross-sectional survey design was employed. Data screening and collation were conducted between September 2024 and September 2025. The study subjects comprised non-Tibetan young adult males who, by December 2024, had been residing continuously at an altitude of 4100 m for 1.5 years. Among the 180 participants, 65 had retinal vascular abnormalities and 115 were normal. Two independent samples rank-sum test and multivariate logistic regression analysis were performed to analyze the association between the hematological and physiological indicators and retinal vascular abnormalities.

The incidence of retinal vascular abnormalities was 36.11%. Two independent samples rank-sum test showed no statistical difference between the 2 groups in chronic mountain sickness (CMS) (P=0.527), while the P-values less than 0.2 were observed in term of heart rate (P=0.033), average visual reaction time (P=0.07), γ-glutamyl transferase (P=0.18), total cholesterol (P=0.033), triglycerides (P=0.149), low-density lipoprotein (P=0.095), platelet count (P=0.141), and plateletcrit (P=0.066). Multivariate logistic regression analysis revealed that heart rate (OR=1.033, 95%CI: 1.003 to 1.064, P=0.033) and total cholesterol (OR=1.868, 95%CI: 1.004 to 3.477, P=0.049) were positively, while average visual reaction time (OR=0.035, 95%CI: 0.002 to 0.723, P=0.03) was negatively correlated with the risk of retinal vascular changes.

The incidence of retinal vascular abnormalities is relatively high among healthy young men who have resided in high-altitude areas for 1.5 years. Increased heart rate and elevated total cholesterol level are independent risk factors for retinal vascular changes, while prolonged visual reaction time is associated with a reduced risk of such changes.

Regular fundus photography helps identify retinal vascular changes at an early stage, which has important clinical significance for preventing the occurrence and development of high-altituderelated retinopathy and even high-altitude cerebral edema. It is recommended to include fundus photography in the health monitoring system for personnel residing in high-altitude areas.