Prediction of Blood Viscosity Based on Usual Hematological Parameters in a Clinically Healthy Population Living in a High-Altitude City

Huamaní, Charles, William Sarmiento, Golda Córdova-Heredia, Luz Cruz-Huanca, Paulina Damián-Saavedra, and Dario Antonio. Prediction of blood viscosity based on usual hematological parameters in a clinically healthy population living in a high-altitude city. High Alt Med Biol . 23:78–84, 2022. Background and Aims: Variations in blood viscosity are mainly determined by the hematocrit level, but in residents of high-altitude cities, the hemoglobin levels and blood viscosity values are often high. We aimed to determine the blood viscosity values in clinically healthy chronic hypoxia-acclimatized individuals and establish a predictive model based on the hematocrit level and other common hematological parameters. Methods: A prospective observational study was conducted in asymptomatic young adults living in Cusco (a city located at 3,399 m). Venous blood samples were collected to determine the hemoglobin, hematocrit, and albumin and serum protein levels and blood viscosity values. Results: Altogether, 253 volunteers were included, of whom 147 (58.1%) were women. The hematological values were mean values of hemoglobin, 16.32 ± 2.0 g/dl; hematocrit, 48.12% ± 5.24%; triglycerides, 130.68 ± 90.64 mg/dl; globulin, 3.07 ± 0.36 g/dl; and mean blood viscosity, 6.17 ± 0.94 centipoises. The prediction model with the highest explained variance ( R 2 = 68.07%) and parsimony conservation comprised hematocrit, globulin, and triglycerides blood viscosity = hematocrit × (0.176) + globulin × (0.595) + triglycerides × (1.77/1,000) − 4.13. Conclusions: In a population living at high altitude, the blood viscosity level is extremely high and mainly determined by the hematocrit level. This population has chronic high blood viscosity levels, which can be predicted using other blood elements.