Benefits of Estrogen for TRT Patients

[readalot]

Respectfully, you aren’t getting it. I am differentiating the two. With your logic, you call erythrocytosis harmless, therefore it must be harmless. What’s scary is you don’t seem to understand that. Go read my posts. I outline all of this. Here’s one verbatim from ExcelMale:

THE DETERMINATION OF BLOOD VISCOSITY IN MAN BY A METHOD BASED ON POISEUILLE’S LAW

THE APPARENT VISCOSITY OF BLOOD FLOWING IN THE ISOLATED HINDLIMB OF THE DOG, AND ITS VARIATION WITH CORPUSCULAR CONCENTRATION.

So the formula that does a very nice job fitting all that pretty data in mammals is referred to as Hatschek’s formula (hat tip). That is viscosity is equal to viscosity of plasma divided by the quantity of (1-hematocrit raised to the 1/3 power).

So if you take this formula and manipulate to take the derivative of the viscosity with respect to hematocrit (I’ll spare you), you can plot out how quickly the function is increasing (rate aka slope) at any point on the curve of hematocrit vs apparent viscosity:

Here I am using a plasma viscosity (eta zero in equation above) of 1.3 cP. The line in blue is viscosity (goes with the left ordinate) and the orange line is the slope of the blue line (goes with the right ordinate or secondary y-axis). You can see blue line goes up pretty linearly but really starts to take off after about 45-50% hematocrit. So going from 50 to 55% hematocrit doesn’t result in the same absolute increase in viscosity as going from 40-45% or 45-50% (it’s more!).

So what about that plasma viscosity term since the equation above isn’t just dependent on hematocrit. Why all that variability in people’s experiences with BP, symptoms and hematocrit?

Why must a practitioner be cautious? When was the last time you had your plasma viscosity measured? I haven’t done it . Ah, finally a test I haven’t run.

So plasma behaves as a Newtonian fluid but its viscosity is a strong function of the proteins within. Take a look at these papers. Guess what really jacks with plasma viscosity, yep you guessed it, inflammation.

Plasma viscosity: a forgotten variable.

Abstract

Evaluation of plasma viscosity has been underutilized in the clinical practice. Plasma viscosity is determined by water-content and macromolecular components. Plasma is a highly concentrated protein solution, therefore weak protein-protein interactions can play a role that is not characterized by electrophoresis. The effect of a protein on plasma viscosity depends on its molecular weight and structure. The less spheroid shape, the higher molecular weight, the higher aggregating capacity, and the higher temperature or pH sensitivity a protein has, the higher plasma viscosity results. Plasma is a Newtonian fluid, its viscosity does not depend on flow characteristics, therefore it is simple to measure, especially in capillary viscosimeters. Its normal value is 1.10-1.30 mPa s at 37 degrees C and independent of age and gender. The measurement has high stability and accuracy, thus little alterations may be pathologically important. Inflammations, tissue injuries resulting in plasma protein changes can increase its value with high sensitivity, though low specificity. It can increase in parallel with erythrocyte sedimentation rate (ESR), but it is not influenced by hematocrit (anemia, polycytemia), or time to analysis. Based on these favorable features, in 1942 plasma viscosity was recommended to substitute ESR. In hyperviscosity syndromes plasma viscosity is better in follow-up than ESR. In rheumatoid arthritis, its sensitivity and specificity are better than that of ESR or C-reactive protein. Plasma fibrinogen concentration and plasma viscosity are elevated in unstable angina pectoris and stroke and their higher values are associated with higher rate of major adverse clinical events. Elevation of plasma viscosity correlates to the progression of coronary and peripheral artery diseases. In conclusion, plasma viscosity should be measured routinely in medical practice.

Plasma viscosity in inflammatory bowel disease

So let’s review an instructive example with two guys, Joe and Bill. Joe has a plasma viscosity of 1.3 cP and Bill (who’s got some immune issues) has a plasma viscosity of 1.5 cP (could be much worse). They both present with hematocrit of 55%. Let’s plot it:

Looking at the graphical construction above, Joe (at a Hct of 55%) has a blood viscosity of 7.2 cP. Bill at same Hct has a blood viscosity of 8.3 cP. Guess where Joe’s Hct would have to be to give the same blood viscosity as Bill? Just a little north of 60%! So Bill’s blood at 55% Hct is behaving the same way Joe’s blood would behave at 60%. An equivalent hematocrit reading in two persons does not necessarily indicate the same blood viscosity. Can you see now why a blanket suggestion that hematocrit levels above reference range are not a big deal is flawed practice? Individual mileage may vary.

But hold on, isn’t this example quite extreme. Are you exaggerating for effect readalot?

Well, if you substitute 1.1 and 1.3 cP (the normal range endpoints given in paper provided above) for Joe and Bill’s plasma viscosity, you draw the exact same conclusions. Modest (10% variation) in plasma viscosity combined with non-linear relationship of serum viscosity vs. Hct can result in very different serum viscosities for two individual’s with the same Hct.

Want even more fun…Here’s the plot for Joe, Bill, and their buddy Jay who all have Hct of 55%. Remember, Joe’s plasma viscosity is 1.3 cP and Bill’s is 1.5 cP. They’re jealous of their super stud buddy Jay who has a very low serum viscosity of 1.1 cP. How do they compare? Jay would need a hematocrit of 65% to match Bill’s serum viscosity even though Bill and Jay have the same hematocrit of 55%.