LAUSR

Objectives: To explore the relationship between daytime resting oxyhemoglobin saturation and metabolic syndrome (MS) in adults living in Tibet, China. Methods: A community-based cross-sectional survey on cardiovascular disease and related risk factors was conducted in Linzi County (altitude of 2900 m above sea level), Lasha (altitude 3650 m) and Anduo County (altitude 4700 m) in the Tibet Autonomous Region in China during 2015 to 2017. The study population included 1 726 subjects (mean age 48.2 years, 42% male) who had information available on pulse oximetry and cardiometabolic risk factors. We used multivariable logistic regression models to analyze the relationship between having lower oxyhemoglobin saturation and MS and its components. Results: Average oxyhemoglobin saturation was 88.6% (interquartile range 85%–93%). Older age, decreased height-adjusted lung function, and higher body mass index (BMI) were associated with having an oxyhemoglobin saturation < 85% (p < 0.01). Adjusting for age, sex, education level, smoking status and other covariates, we found that each 5% decrease in oxyhemoglobin saturation was associated with a higher adjusted odds of MS (OR = 1.17, 95% CI: 1.05–1.34), central obesity (OR = 1.19, 95% CI: 1.10–1.32), lower HDL-C level (OR = 1.29, 95% CI: 1.14–1.47), higher LDL-C level (OR = 1.26, 95% CI: 1.06–1.51). Conclusion: In high-altitude population in Tibet autonomous region, lower resting oxyhemoglobin saturation, was associated with higher odds of having MS. Worsening hypoxia of any degree in high-altitude dwellers may be an independent risk factor for cardiovascular disease.