Blood Pressure Levels and Prevalence of Hypertension in Relation to Altitude and Ethnicity Among an Occupational Health Screening Population on the Qinghai–Tibetan Plateau

<title>Abstract</title> <p> <bold>Objective</bold> To investigate blood pressure levels and hypertension prevalence across altitudes and ethnic groups in an occupational health screening population on the Qinghai–Tibetan Plateau, and to analyze the independent and interactive effects of altitude and ethnicity on blood pressure and hypertension. <bold>Methods</bold> A total of 6,548 participants were enrolled. Data on demographics, altitude, ethnicity, blood pressure, age, sex, BMI, dyslipidemia, and dysglycemia were collected. Statistical analyses included t-tests, ANOVA, chi-square tests, ANCOVA, and binary logistic regression, with stratified analyses by ethnicity. <bold>Results</bold> The overall hypertension prevalence was 20.7% (1,357/6,548): 25.3% in Han, 16.4% in Tibetans, and 23.9% in other ethnic groups (χ² = 48.362, P &lt; 0.001). Prevalence in low- (1,500–2,500 m), moderate- (2,500–3,500 m), and high-altitude (3,500–4,500 m) groups was 28.8%, 15.9%, and 17.6%, respectively (χ² = 78.521, P &lt; 0.001). ANCOVA showed that both altitude and ethnicity had independent main effects on systolic and diastolic blood pressure (all P &lt; 0.05), with significant interactions (SBP: F = 2.865, P = 0.022; DBP: F = 6.310, P &lt; 0.001). The Han–Tibetan blood pressure difference was largest at 2,500–3,500 m. Logistic regression identified altitude as an independent protective factor (P &lt; 0.001), with ORs of 0.417 (95% CI: 0.329–0.530) for moderate altitude and 0.695 (95% CI: 0.550–0.876) for high altitude. Ethnicity main effect and altitude × ethnicity interaction were not significant in the full model. Stratified analyses showed that Tibetans had stronger protective effects at moderate and high altitudes than Han (all P &lt; 0.001). <bold>Conclusions</bold> In this occupational health screening population, blood pressure and hypertension prevalence show significant altitudinal and ethnic disparities, with a significant altitude–ethnicity interaction. Tibetans demonstrate the most pronounced blood pressure advantage and hypertension protection at moderate altitudes. Hypertension prevalence is primarily influenced by altitude and traditional risk factors, while ethnic differences largely reflect physiological adaptive characteristics. </p>