Influence of serological factors and BMI on the blood pressure/hematocrit association in healthy young men and women

Abstract

Beatriz Y Salazar Vázquez,1,2,5 Miguel A Salazar Vázquez,2,3 Adolfo Chávez-Negrete,4 Galileo Escobedo,2 Pedro Cabrales,5 Shankar Subramaniam,5 Marcos Intaglietta,5 Ruy Pérez-Tamayo21Faculty of Medicine, Universidad Juárez del Estado de Durango, Victoria de Durango, Dgo, Mexico; 2Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico; 3Department of Pediatrics, Hospital General de Zona No. 1, Instituto Mexicano del Seguro Social, Durango, Dgo, Mexico; 4Hospital de Especialidades, Instituto Mexicano de Seguro Social, México DF, Mexico; 5Department of Bioengineering, University of California, San Diego, CA, USAAbstract: The association between mean arterial blood pressure (MAP) and hematocrit (Hct) as a surrogate for blood viscosity was investigated in a young (average 20.0±2.3 years), healthy population of 174 men and 442 women. Health status was assessed by clinical examination and serological evaluation. Individuals with severe anemia or hemoconcentration, prior traumas or major surgical intervention, smokers, and pregnant or lactating women were excluded from the study. The MAP/Hct association was positive and significant (P=0.04) for women and negative, albeit not significantly so, for men. The MAP/Hct association was also evaluated in subgroups of the same population with a progressive step-by-step exclusion of: individuals with cholesterol >200 mg/dL; triglycerides >200 mg/dL; body mass index >25 kg/m2; and glucose >100 mg/dL. This consecutively reduced the strength of the positive MAP/Hct association in women, which became negative – although not significantly so – when all anomalously high factors were excluded. The same trend was found in men. Our study indicates that previously reported positive trends in the relationship between the MAP and Hct in the population are not present in a young, healthy population of men or women that excludes individuals with the confounding factors of above normal serological values and BMI.Keywords: blood pressure, blood viscosity, hematocrit, vascular resistance, endothelial dysfunction