Blood Pressure and Hematocrit in Diabetes and the Role of Endothelial Responses in the Variability of Blood Viscosity
- Beatriz Y. Salazar-Vazquez, MD, MSC1,
- Marcos Intaglietta, PHD2,
- Martha Rodríguez-Morán, MD, MSC, PHD1 and
- Fernando Guerrero-Romero, MD, PHD1
- 1Medical Research Unit, Mexican Social Security Institute, Durango, México
- 2Department of Bioengineering, University of California San Diego, La Jolla, California
- Address correspondence and reprint requests to Dr. Fernando Guerrero-Romero, Mexican Social Security Institute, Siqueiros 225 esq/Castañeda, 34000 Durango, Dgo, México. E-mail: guerrero_romero{at}hotmail.com
Abstract
OBJECTIVE—To investigate the relationship between mean arterial blood pressure and hematocrit in a population of treated diabetic patients and a control population of healthy individuals.
RESEARCH DESIGN AND METHODS—Data on hematocrit and blood pressure were obtained from 129 diabetic subjects (87 women and 42 men) and 103 healthy subjects (76 women and 27 men) enrolled in a cross-sectional study. Alcohol consumption, ischemic heart disease, stroke, neoplasia, renal, hepatic, and chronic inflammatory disease were exclusion criteria.
RESULTS—The hematocrit of diabetic patients ranged from 0.35 to 0.52, and blood pressure had a bimodal distribution described by a second-order polynomial (P < 0.001), whereby elevated pressures correlated with low and high hematocrit, while the minimum average pressure was at hematocrit 0.43. Hematocrit of normal control subjects (range 0.28–0.55) was uncorrelated to blood pressure (averaged 99.7 ± 9.7 mmHg). High blood pressure, low hematocrit diabetic subjects up to the minimum average hematocrit of 0.43 had a negative correlation (P < 0.0001) between these variables.
CONCLUSIONS—Our findings are compatible with the hypothesis that diabetic patients present normal responses to hematocrit variation and therefore blood viscosity and shear stress in mediating the release of vasodilators and lack the ability to autoregulate blood pressure relative to differences in hematocrit by comparison to nondiabetic subjects. These findings also suggest that the treatment of diabetes should target maintaining an optimal hematocrit in order to lower cardiovascular risk.
Footnotes
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A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C Section 1734 solely to indicate this fact.
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- Accepted April 14, 2006.
- Received February 8, 2006.
- DIABETES CARE
