Introducing our NEW Whole Blood Viscosity Profile

Intended Use
Meridian Valley Lab’s new Blood Viscosity Profile is a whole blood viscosity test that monitors changes in the thickness and stickiness of blood.

Blood viscosity is a direct measure of the blood’s ability to flow. The “flowability” of blood has a critical effect on the perfusion of tissues, delivery of oxygen to cells, damage to vessel walls, and the likelihood of blood to clot abnormally. Thus, blood viscosity can be an important diagnostic parameter in many conditions, including Cardiovascular Disease, diabetes, Cognitive Decline, ocular disorders, pre-eclampsia, autoimmune conditions and migraines, among others.

Blood Viscosity and Cardiovascular Risk
Blood viscosity is the only biological parameter that has been correlated with all of the major cardiovascular risk factors including male gender, age, smoking, obesity, diabetes, hypertension, and LDL cholesterol. It is inversely correlated with HDL cholesterol. However, blood viscosity is a statistically independent — and in certain ways, much stronger — biomarker for cardiovascular disease. Blood viscosity predicts heart attacks, strokes and mortality from heart disease independent of these other risk factors.

The role that blood viscosity plays in cardiovascular health is highly significant. Thicker, stickier blood is more abrasive and damages arterial walls. Thus, it not only affects how hard the heart has to work to circulate the blood, but also contributes to inflammation of the intimal lining of the vessels. It contributes to endothelial dysfunction, growth of atherosclerotic lesions, and plaque rupture. In addition, blood viscosity directly modulates peripheral vascular resistance. Impaired blood flow due to hyperviscosity leads to decreased oxygen and nutrients delivered to the tissues, affecting critical areas such as the brain, eyes, and kidneys. There can be many underlying factors that correlate with high viscosity, such as Dehydration and Blood Pressure.

Measuring Blood Viscosity
Like blood pressure, viscosity is a dynamic parameter which changes during each cardiac cycle as a result of changing flow velocity. Blood is thinner at systole, when it is flowing at a higher velocity. At diastole, blood is 2 to 5 times thicker. For blood viscosity measurements to be meaningful, they must include both systolic and diastolic measurements.

Until now, the viscosity testing that has been commercially available has been of limited utility. The methodology used in these older methods employs an industrial viscometer designed for measuring the viscosity of house paint or engine oil and reports only systolic blood viscosity, supplying only half of the picture.

Meridian Valley Laboratory Methodology

Blood viscosity measurements are performed using the Hemathix SCV-200 automated scanning capillary tube viscometer, which is capable of measuring viscosity over the complete range of physiologic values experienced in a cardiac cycle (10,000 shear rates) with a single continuous measurement. This methodology represents a breakthrough in blood viscosity testing that provides a complete picture of blood viscosity changes in each patient. This allows the physician to make significant treatment decisions toward improving the patient’s quality of life and health outcome.

Meridian Valley Lab is proud to be the only laboratory in North America offering this state-of-the-art testing for blood viscosity.

Specimen Collection
The blood viscosity test requires 3 tubes of 3-4 cc of EDTA-anticoagulated whole blood, which is collected at your office, clinical site or facility, and shipped priority-overnight to our laboratory. Use standard lavender vacutainers and gently invert them at least 4 times to ensure thorough mixing. Specimens must be refrigerated at 2-8°C and tested within 4 days of collection; frozen samples are not acceptable.

Blood Viscosity Report
The blood viscosity test report includes a CBC and scores for both systolic and diastolic blood viscosity. Systolic viscosity represents the thickness of blood and is affected by the patient’s hematocrit as well as the deformability of red blood cells and the concentration of plasma proteins (plasma viscosity). Diastolic viscosity represents the stickiness of blood and is affected by the aggregation of red blood cells, inflammatory factors, and the concentration of fibrinogen and immunoglobulins.