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Published on: October 22, 2014
Plasma viscosity is increased in subjects with elevated ankle brachial index
Insights
Increased plasma viscosity is linked to higher arterial stiffness, as measured by ankle-brachial index (ABI). This finding helps explain the elevated cardiovascular risk in individuals with poorly compressible arteries.
Area of Science:
- Cardiovascular Medicine
- Vascular Biology
- Hemodynamics
Background:
- Peripheral artery occlusive disease (PAOD) signifies heightened cardiovascular risk (CVR).
- Increased arterial stiffness, particularly in lower limb arteries, is also associated with elevated CVR.
- Poorly compressible arteries (PCA) may present an even greater CVR than PAOD, with limited data on hemorheological factors' role.
Purpose of the Study:
- To investigate the association between blood and plasma viscosity and elevated ankle-brachial index (ABI).
- To explore hemorheological factors contributing to increased arterial stiffness.
Main Methods:
- Sixty-two subjects with ABI 1.3-1.4 and 20 with ABI >1.4 were recruited from a cardiovascular disease screening.
- Control groups were matched for age, sex, and cardiovascular disease risk factors (blood pressure, lipids, glucose, smoking, obesity).
- Blood and plasma viscosities were measured using a cone-plate viscometer; ABI served as the measure of arterial stiffness.
Main Results:
- Subjects with elevated ABI values exhibited significantly higher plasma viscosity compared to matched controls.
- Plasma viscosity was elevated in both ABI 1.3-1.4 and ABI >1.4 groups (p < 0.001 and p < 0.01, respectively).
- No significant difference in blood viscosity was observed between groups.
Conclusions:
- Plasma viscosity is elevated in individuals with increased arterial stiffness (elevated ABI), independent of other cardiovascular risk factors.
- This finding provides a potential explanation for the heightened cardiovascular risk observed in patients with poorly compressible arteries (PCA).
- Hemodynamic factors, specifically plasma viscosity, play a role in arterial stiffness and associated cardiovascular risk.
Objective:
Peripheral artery occlusive disease (PAOD) is associated with increased cardiovascular risk (CVR). Recently it has been reported that also the increased stiffness of lower limb arteries is associated with increased CVR. In particular, subjects with poorly compressible arteries (PCA) appear to have a CVR even higher than that of subjects with PAOD. Limited data are available on the role of hemorheological factors in determining increase in arterial stiffness. Our study aimed to investigate possible association between blood and plasma viscosity and elevated ankle brachial index (ABI).
Methods:
Subjects were free-living participants to a cardiovascular disease screening campaign. Sixty-two subjects with ABI ranging 1.3-1.4, and 20 with ABI >1.4 were matched with 124 and 40 control subjects, respectively. Cardiovascular disease risk factors (blood pressure, blood lipids, glucose, cigarette smoking, obesity) were evaluated by routine methods. Blood and plasma viscosities were measured by a cone-plate viscometer. Ankle-brachial index was computed as measure of arterial stiffness.
Results:
Compared with controls, who were carefully matched for age, sex and all cardiovascular risk factors, subjects with elevated ABI values had increased levels of plasma viscosity (1.42 ± 0.11 vs. 1.35 ± 0.10 cP, p < 0.001, for subjects with ABI ranging 1.3-1.4, and 1.41 ± 0.10 vs. 1.33 ± 0.10 cP, p < 0.01, for subjects with ABI >1.4). No difference in blood viscosity was observed.
Conclusion:
The present investigation provides evidence that plasma viscosity is increased in subjects with elevated ABI values, independently of other cardiovascular risk factors. This finding contributes to explain the high CVR of patients with PCA.
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