Serum Albumin Levels in Healthy Adults from Plateau and Plains: A Cross-Sectional Study

Objective This study aims to compare serum albumin levels among healthy adults residing in the plateau and plains of Sichuan Province, China. Methods In this study, data from 464 adults who underwent annual health check-ups at the same center were analyzed. Participants were categorized into a plains group (n=244; ∼500 m) and a plateau group (n=220; ∼3500 m). Group comparisons were made using χ 2 and t tests. Linear regression and logistic regression models were employed to assess risk factors. Results The mean serum albumin level was significantly lower in the plateau group (42.9±2.6 g·L –1 ) compared with the plains group (45.6±3.0 g·L –1 ; P <0.001). Hypoalbuminemia (<40 g·L –1 ) prevalence was higher in plateau residents than in plains residents ( P <0.001). In linear regression adjusting for covariates, the plateau group had a mean albumin level 2.41 g·L –1 lower than the plains group (95% CI −2.89 to −1.93; P <0.001). Logistic regression results were consistent (plateau: adjusted odds ratio [aOR]=2.90, 95% CI 1.37–6.16, P =0.005; hemoglobin: aOR=0.957 per g·L –1 , 95% CI 0.929–0.986, P =0.004; age: aOR=1.03 per year, 95% CI 1.01–1.05, P =0.011). Conclusion Healthy high altitude residents have lower serum albumin levels than plains residents. These findings suggest that the conventional albumin reference range may need reevaluation for high altitude populations.