Plasma viscosity and insulin resistance in metabolic syndrome

Abstract

There are some reports concerning the relationship between insulin sensitivity and whole-blood viscosity calculated 1,2 or measured. 3,4 On the other hand we know that in obese subjects, characterized by an alteration of insulin sensitivity, a hyperviscosity condition is present and that in these subjects weight reduction especially affects plasma viscosity and not the other haemorheological determinants. 5,6 We examined, in a group of subjects with metabolic syndrome (MS) defined according to the WHO criteria, 7 the relationship between plasma viscosity and the parameters reflecting insulin-resistance.In 19 subjects with MS (nine men and 10 women; mean age 49.0 AE 10.2 y body mass index (BMI) 33.3 AE 4.5 kg=m 2 waist -hip ratio (WHR) 0.915 AE 0.071; systolic blood pressure 135.8 AE 19.3 mmHg; diastolic blood pressure 83.4 AE 6.2 mmHg; fasting blood glucose level 9.12 AE 3.56 mmol=l; Hb Alc 7.06 AE 1.84%; microalbuminuria 5.7 AE 3.2 ng=min), the insulin sensitivity was assessed by performing a euglycaemic hyperinsulinaemic clamp and considering the glucose disposal (M), expressed as mg=kg=min and calculated on the basis of the glucose amount infused, and the glucose metabolic clearance rate (MCR), expressed as ml=kg=min and calculated by dividing the amount of metabolized glucose (M) by the plasma glucose concentration. In these subjects, plasma viscosity (PV) was determined on fasting venous blood anticoagulated with ethylenediaminetetracetate (EDTA), at the shear rate of 450 s 71 , using the viscosimeter Wells-Brookfield 1 2 LVT. Between normal subjects and patients with MS there was a significant difference in plasma viscosity (n ¼ 1.24 AE 0.08, MS ¼ 1.40 AE 0.10, P < 0.001). This haemorheological parameter was negatively correlated to the values of M (r 2 ¼ 0.398, P < 0.01) and MCR (r 2 ¼ 0.370, P < 0.01).We then observed that the trend of the PV is related to both parameters reflecting the insulin-resistance, revealing how its behaviour is influenced by the degree of resistance. Besides considering the PV another component of the MS, our interest in underlining these relationships was motivated by the consideration that insulin-resistance and PV impair the microhaemodynamic pattern, and this impairment may be one of the links not only between insulin-resistance and the principal features (diabetes mellitus, hypertension, obesity etc) of MS, but also between insulin-resistance and the vascular complications accompanying this syndrome.

Blood Viscosity and Hematocrit as Risk Factors for Type 2 Diabetes Mellitus: The Atherosclerosis Risk in Communities (ARIC) Study

“…Since 1965, there have been 10 cross-sectional studies ( 8 – 16 , 31 ) of rheologic parameters related to insulin resistance. Eight smaller studies found that high levels of whole blood viscosity were associated with insulin resistance measured by euglycemic hyperinsulinemic clamp ( 8 , 10 – 12 , 14 – 16 , 31 ). Two larger studies found an association between high whole blood viscosity and markers of insulin resistance ( 9 , 13 ).…”

Increased plasma viscosity in young women with polycystic ovary syndrome using an oral contraceptive containing 35 μg ethinyl estradiol and 2 mg cyproterone acetate

“…Chronic hyperviscosity is very frequent in patients with MS and IR [28], as well as in severely obese subjects [29,30]. There is a strong association between PV and IR [31] and the resulted impairment in microcirculation might be one of the links between IR and the vascular complications of MS [28]. PV has been proved to be an independent and powerful predictor of cardiac events and mortality [15,16,18] and it may be used to detect the early microhemodynamic alterations present in atherosclerosis [30].…”

“…It is an indicator of blood flow in the network of small blood vessels constituting microcirculation: an elevated PV means increased resistance to blood flow in most tissues of the body and hence possible target -organ damage [27]. Chronic hyperviscosity is very frequent in patients with MS and IR [28], as well as in severely obese subjects [29,30]. There is a strong association between PV and IR [31] and the resulted impairment in microcirculation might be one of the links between IR and the vascular complications of MS [28].…”

Red Blood Cells from Individuals with Abdominal Obesity or Metabolic Abnormalities Exhibit Less Deformability upon Entering a Constriction

“…According to recently published NHANES data, 34% of the adult US population exhibit MS characteristics [ 8 ]. Due to the prevalence of abdominal obesity, MS or other metabolic abnormalities such as insulin resistance and chronic inflammation and associations with increased risk of cardiovascular morbidity and mortality [ 9 , 10 , 11 ], much work has focused on understanding the contribution of hemorheological alterations to MS [ 12 – 19 ]. The prothrombotic conditions associated with metabolic abnormalities have been shown to increase plasma coagulation, reduce fibrinolysis, decrease endothelial thromboresistance, and cause platelet hyperactivity [ 20 ].…”