Association of Whole Blood Viscosity With Metabolic Syndrome in Type 2 Diabetic Patients: Independent Association With Post-Breakfast Triglyceridemia

Whole blood viscosity is associated with reduced myocardial mechano-energetic efficiency in nondiabetic individuals

INTRODUCTION

This cross-sectional study aimed to investigate the association between myocardial mechano-energetic efficiency (MEE) and whole blood viscosity (WBV) in nondiabetic adults participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study.

METHODS

1143 participants underwent an oral glucose tolerance test and an echocardiogram for myocardial MEE per gram of left ventricular mass (MEEi) measurement. WBV was measured as: [0.12 × h] + [0.17 × (p-2.07)], where h is haematocrit and p is plasma protein levels.

RESULTS

Study population includes 595 males and 548 females with a mean age of 46 ± 12 years and a mean BMI of 30.0 ± 6.2 kg/m2 . Individuals with normal glucose tolerance were 63%, while those with impaired fasting glucose, impaired glucose tolerance and or the combination of both were 14.3%, 13% and 9.7%, respectively. A univariate analysis showed that MEEi was significantly associated with sex, age, smoking, BMI, waist circumference, total cholesterol, HDL, triglycerides, fasting glucose, fasting insulin, HOMA-IR index, glucose tolerance, C-reactive protein, haematocrit, haemoglobin, plasma protein and WBV. In a multivariable regression model including variables that were significantly associated with MEEi in univariate analysis, MEEi was associated with HOMA-IR (β = -0.144, p < .001), age (β = -0.140, p < .001), WBV (β = -0.129, p < .001) and glucose tolerance (β = -0.064, p = .04). The independent association between WBV and MEEi remained statistically significant (β = -0.122, p < .001) when antihypertensive therapy and lipid-lowering therapy were included in the model.

CONCLUSION

WBV is associated with decreased myocardial MEE independently of other cardiovascular risk factors.

Calculated whole blood viscosity in non-diabetic subjects with asymptomatic carotid atherosclerosis: How insulin resistance may affect blood viscosity

BACKGROUND AND OBJECTIVE

Asymptomatic atherosclerosis is an important early marker of vascular damage and, among its risk factors, hemorheological alterations play an important role.

PATIENTS AND METHODS

In a cohort of 85 non-diabetic subjects with asymptomatic carotid atherosclerosis (ACA), we have measured whole blood viscosity (cWBV) according to the haematocrit and plasma fibrinogen level. The cWBV distinguish the subgroup of ACA subjects with 3-5 cardiovascular risk factors (CRFs) from that with 1-2 CRFs and the same behavior is present for haematocrit and plasma fibrinogen level. Therefore, we divided the whole group of ACA subjects according to the medians of the four surrogate indexes with an insulin resistance degree of TG/HDL-C, TyG, VAI and LAP.

RESULTS

The analysis of the correlation between cWBV and each index of insulin resistance has shown that no correlation is present in the whole group and in the group of ACA subjects with 1-2 CRFs, while in the subgroup with 3-5 CRFs there is a positive correlation between cWBV with TG/HDL-C and TyG at a low degree of statistical significance.

CONCLUSIONS

The date underline that subjects with this clinical condition have an unaltered evaluation of the cWBV compared to the other indices.

Uric acid and uric acid/creatinine ratio and their correlations with the hemorheological determinants in subjects with subclinical carotid atherosclerosis

BACKGROUND AND OBJECTIVE

we have examined the concentration of serum uric acid and the serum uric acid/creatinine ratio as well as their correlations with the main determinants of the hemorheological profile in a group of subjects with subclinical carotid atherosclerosis.

METHODS

we evaluated the concentration of serum uric acid and the serum uric acid/creatine ratio in 43 men and 57 women [median age 66.00 (25)] with subclinical carotid atherosclerosis, subsequently divided according to the number of traditional cardiovascular risk factors and to the insulin resistance degree.

RESULTS

serum uric acid, but not the serum uric acid/creatinine ratio, results strongly influenced by the number of cardiovascular risk factors and by the insulin resistance degree. In the whole group and in the subgroups of subclinical carotid atherosclerosis subjects, serum uric acid and serum uric acid/creatinine ratio show significant correlation, besides with whole blood viscosity, with plasma viscosity and erythrocyte aggregation. The influence of the serum uric acid on the erythrocyte aggregability that is a part of the erythrocyte aggregation is to ascribe to the action carried out by serum uric acid on the erythrocyte zeta potential.

CONCLUSIONS

it is reasonable to think that the treatment of the asymptomatic or symptomatic hyperuricemia with the urate-lowering therapy that reduces the serum uric acid concentration may reflect on the hemorheological profile which role on the atherosclerotic cardiovascular disease is well known.

Biological Applications of Electron Paramagnetic Resonance Viscometry Using a 13C-Labeled Trityl Spin Probe

Alterations in viscosity of biological fluids and tissues play an important role in health and diseases. It has been demonstrated that the electron paramagnetic resonance (EPR) spectrum of a 13C-labeled trityl spin probe (13C-dFT) is highly sensitive to the local viscosity of its microenvironment. In the present study, we demonstrate that X-band (9.5 GHz) EPR viscometry using 13C-dFT provides a simple tool to accurately measure the microviscosity of human blood in microliter volumes obtained from healthy volunteers. An application of low-field L-band (1.2 GHz) EPR with a penetration depth of 1-2 cm allowed for microviscosity measurements using 13C-dFT in the living tissues from isolated organs and in vivo in anesthetized mice. In summary, this study demonstrates that EPR viscometry using a 13C-dFT probe can be used to noninvasively and rapidly measure the microviscosity of blood and interstitial fluids in living tissues and potentially to evaluate this biophysical marker of microenvironment under various physiological and pathological conditions in preclinical and clinical settings.

Blood Viscosity, Glycemic Markers and Blood Pressure: A Study in Middle-Aged Normotensive and Hypertensive Type 2 Diabetics

Altered blood viscosity (BV) may affect blood pressure (BP) and develops further complications in diabetes. A case-control study was performed to examine the relationship of erythrocyte sedimentation rate (ESR), hematocrit, fibrinogen, and BV with glycemic markers and BP in middle-aged normotensive and hypertensive type 2 diabetic patients and healthy controls. A total of 145 participants between age group 30-50 years divided into three groups; controls (n = 60), type 2 diabetes mellitus (T2DM, n = 55), and T2DM with hypertension (T2DM + HTN, n = 30). ESR and hematocrit were determined by Wintrobe's method. Plasma fibrinogen was measured using Lempert method and BV calculated using Merill's formula. T2DM and T2DM + HTN patients had higher fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), ESR, and fibrinogencompared to controls. In both male and female SBP, DBP, MAP, FPG, and HbA1c were significantly higher in T2DM and T2DM + HTN groups, compared to controls. Further, linear regression analysis revealed a positive association of ESR and fibrinogen with SBP, DBP, MAP, FPG, HbA1c, and positive diabetic status in all participants. Also, in the same analysis, BV showed a positive association with SBP, DBP, and MAP. The association of ESR and fibrinogenwith glycemic markers and BP in diabetes supporting the value of emerging marker's for early prediction of T2DM and hypertension.

Hemorheological alterations in adults with prediabetes identified by hemoglobin A1c levels

BACKGROUND AND AIMS

A link between increased blood viscosity and type 2 diabetes has been previously reported. Herein, we investigated the association of blood viscosity with prediabetes, identified by glycated hemoglobin A1c (HbA1c) according to the new American Diabetes Association criteria, and subclinical atherosclerosis.

METHODS AND RESULTS

The study cohort includes 1136 non-diabetic adults submitted to anthropometrical evaluation, an oral glucose tolerance test and ultrasound measurement of carotid intima-media thickness (IMT). Whole blood viscosity was estimated using a validated formula based on hematocrit and total plasma proteins. After adjusting for age, and gender, individuals with HbA1c-defined prediabetes (HbA1c 5.7-6.4% [39-47 mmol/mol]) exhibited significantly higher values of hematocrit, and predicted blood viscosity as compared with controls. Increased levels of IMT were observed in subjects with HbA1c-defined prediabetes in comparison to controls. Predicted blood viscosity was positively correlated with age, waist circumference, blood pressure, cholesterol, triglycerides, fibrinogen, white blood cell, HbA1c, fasting and 2-h post-load glucose levels, fasting insulin, IMT and inversely correlated with HDL and Matsuda index of insulin sensitivity. Of the three glycemic parameters, i.e. HbA1c, fasting and 2-h post-load glucose, only HbA1c showed a significant correlation with predicted blood viscosity (β = 0.054, P = 0.04) in a multivariate regression analysis model including multiple atherosclerosis risk factors.

CONCLUSION

The study shows that individuals with HbA1c-defined prediabetes have increased predicted blood viscosity and IMT. The HbA1c criterion may be helpful to capture individuals with an increased risk of diabetes and cardiovascular disease who may benefit from an intensive lifestyle intervention.