The Effects of Low-Density Lipoprotein and High-Density Lipoprotein on Blood Viscosity Correlate with their Association with Risk of Atherosclerosis in Humans

Abstract

1. Increased blood or plasma viscosity has been observed in almost all conditions associated with accelerated atherosclerosis. Cognizant of the enlarging body of evidence implicating increased viscosity in atherogenesis, we hypothesize that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their association with risk of atherosclerosis. 2. Blood viscometry was performed on samples from 28 healthy, non-fasting adult volunteers using a capillary viscometer. Data were correlated with haematocrit, fibrinogen, serum viscosity, total cholesterol, high-density lipoprotein-cholesterol, triglycerides and calculated low-density lipoprotein-cholesterol. 3. Low-density lipoprotein-cholesterol was more strongly correlated with blood viscosity than was total cholesterol (r = 0.4149, P = 0.0281, compared with r = 0.2790, P = 0.1505). High-density lipoprotein-cholesterol levels were inversely associated with blood viscosity (r = -0.4018, P = 0.0341). 4. To confirm these effects, viscometry was performed on erythrocytes, suspended in saline, which had been incubated in plasma of various low-density lipoprotein/high-density lipoprotein ratios. Viscosity correlated directly with low-density lipoprotein/high-density lipoprotein ratio (n = 23, r = 0.8561, P < 0.01). 5. Low-density lipoprotein receptor occupancy data suggests that these effects on viscosity are mediated by erythrocyte aggregation. 6. These results demonstrate that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity in healthy subjects correlate with their association with risk of atherosclerosis. These effects on viscosity may play a role in atherogenesis by modulating the dwell or residence time of atherogenic particles in the vicinity of the endothelium.

The effects of weight loss due to gastric banding and lifestyle modification on red blood cell aggregation and deformability in severe obese subjects

“…This supports the concept that an increase in LDL-Chol is a risk factor for atherosclerosis. 25 Other Authors have hypothesized that LDL-Chol can modulate blood viscosity by a mechanism similar to the one operated by fibrinogen. 26 In this study we observed a reduction in the AI % and an increase in the AI t 1 2 in obese patients who lost weight after the application of adjustable gastric banding.…”

Elevated 1-h post-challenge plasma glucose levels in subjects with normal glucose tolerance or impaired glucose tolerance are associated with whole blood viscosity

“…Increased lipoproteins concentration may be another shared mechanism linking blood viscosity [3,39] and elevated 1-h post-challenge plasma glucose [33]. Low HDL levels have been associated with an elevated blood viscosity [3].…”

“…Evidence has accrued suggesting that subjects with a 1-h plasma glucose concentration during an oral glucose tolerance test (OGTT) [155 mg/dl (8.6 mmol/l) are at increased risk of type 2 diabetes among those who have NGT [28][29][30][31]. Remarkably, subjects with 1-h postchallenge plasma glucose [155 mg/dl are characterized by a cluster of cardio-metabolic abnormalities such as insulin resistance [32], pro-atherogenic lipid profile [33], hepatic steatosis [34], carotid atherosclerosis [35], vascular stiffness [36], and left ventricular hypertrophy [37], and cardiac autonomic imbalance [38] which in turn have been inked to increased blood viscosity [1,3,[7][8][9][10][11]. The degree to which 1-h post-load plasma glucose [155 mg/dl is associated with blood viscosity remains unsettled.…”

“…plasma, plasma proteins and red blood cells, and it is a measure of the intrinsic resistance of blood to flow. Increased blood viscosity has been reported to be related with major cardiovascular risk factors including hyperlipidemia, diabetes mellitus, hypertension, cigarette smoking, metabolic syndrome, obesity, hyperfibrinogenemia [1][2][3][4][5][6]. In addition, whole blood viscosity has been found to be associated with left ventricular hypertrophy, atherosclerosis, vascular stiffness, and non-alcoholic fatty liver, as well as to predict cardiovascular diseases [7][8][9][10][11][12][13][14][15].…”

Hematology and plasma biochemistry in rats fed with diets enriched with fatty fishes from Amazon region

“…For example, high-fat diets change blood cell-related characteristics, increase total cholesterol and Low Density Lipoprotein-cholesterol (LDL-c), and decrease HDL-c. On the other hand, low levels of fatty acids increase blood viscosity and the risk of atherosclerosis 18 . Blood viscosity increases when hematocrit, number of circulating erythrocytes, or cell volume increases.…”