Blood viscosity and you will hypertension: role away from temperature and hyperglycemia

Yildirim Cinar, A good. Mete Senyol, Kamber Duman, Bloodstream viscosity and hypertension: role out-of heat and you can hyperglycemia, Western Diary out of Blood pressure levels, Frequency fourteen, Material 5, , Pages 433–438,

Conceptual

We planned a study to research the relations among blood pressure (BP), viscosity, and temperature in healthy subjects and among BP, viscosity, and glucose in diabetics. With simple random sampling method, 53 healthy and 29 diabetes mellitus (DM) type II subjects were selected. Parameters were determined with capillary viscometer and glucometer at 22°C, 36.5°C, and 39.5°C in healthy subjects, and at 22°C on diabetic patients during OGTT with 75 g of glucose. Statistical evaluations of the data were made with regression analysis, Student t test, Spearman’s correlation, and analysis of variance. When temperature decreased from 36.5°C to 22°C, blood viscosity increased %. This increase resulted in a % decrease in blood flow rate. According to the Hagen-Poiseuille equation, the required BP increase for compensation of the resulting tissue ischemia was %. Also, a % decrease in erythrocyte deformability and % increase in plasma viscosity were seen. When temperature increased from 36.5° to 39.5°C, blood viscosity decreased %. This caused % decrease in blood flow rate, and % decrease in BP, according to the equation. Erythrocyte deformability increase of 9.92% and plasma viscosity decrease of 4.99% arose from the temperature rise. There is a correlation between total data for temperatures and viscosities (r = ?0.84, P < .001). When the mean value of blood glucose increased from 100 to 400 mg/dL, viscosity increased 25% (r = 0.59, P = .002). In this state, blood flow rate decrease was 20% and BP increase for physiological compensation was 25%. Consequently, temperature, glucose and viscosity levels of blood are important factors for BP. Am J Hypertens 2001;–438 © 2001 American Journal of Hypertension, Ltd.

The goal of our studies is to try to look into the relationships certainly one of heat, glucose amount, and viscosity out-of blood and you will plasma, also to estimate its outcomes towards blood pressure levels (BP) centered on Hagen-Poiseuille’s hydrodynamics picture.

If the human circulatory system is considered as a closed system, hemodynamic equilibrium can be determined according to Poiseuille’s equation through the pressure, viscosity, flow rate, velocity of blood, and vessel diameter. Viscosity can be defined as the resistance of fluids against flow. The resistance for blood circulation includes friction between the blood elements and between the vessel lumen and blood. To make a fluid flow, the application of energy is required. Therefore, the energy of the circulatory system is spent in correlation with the viscosity level of blood. Energy forms of the circulatory system are BP and blood flow velocity. The velocity (v) and pressure of blood flow can be determined with Poiseuille’s equation as v = 1/4?L (F₁ ? F₂) (a 2 ? r 2 ), and also BP rate (Q) can be expressed from the above equation as Q = ?a 4 /8 ?L (F₁ ? F₂), where ? is the viscosity of the fluid, F₁ and F₂ are the initial and the final cross sectional pressures of blood, L is the length, a is the radius of vessel, and r is the distance from the center of the vessel for a flowing particle. 1, 2 Thus, to keep the equilibrium of the equation constant in the circulatory system, BP will increase when viscosity increases.

Blood viscosity and you will blood pressure: role out-of heat and you may hyperglycemia

It’s been shown one couples hooking up to ranging from % and you may % values out-of hematocrit, all of the eleven% upsurge in hematocrit grows bloodstream viscosity from the 20%. Within state, according to Poiseuille’s equation, blood supply speed decrease by %, which may produce cells ischemia. To save brand new circulatory system from inside the equilibrium (which is, keeping the move speed adequate and you will preventing tissue ischemia), an effective 20% increase in BP otherwise cuatro.66% vasodilation will become necessary. step 3 Although not, the human being circulatory system is not a precise signed program, because the blood viscosity should be changed into the assimilation from dining otherwise pills. 4–8 At the same time, the consequences of fat molecules and of specific medication towards the bloodstream viscosity and hemodynamics for example BP had been advertised. Because atherosclerotic boats you should never dilate sufficiently once the a reaction to vasodilator pills, it’s been ideal you to definitely enhanced bloodstream viscosity can just only end up being settled that have a good BP increase in eg issues. 9–a dozen Together with, the newest relationship certainly one of BP, nightmare, coagulation, blood supply speed, and you will blood viscosity were revealed through the beliefs of hemodynamics. thirteen, fourteen