Hematocrit drives Blood Viscosity- Does that Matter in Men on TRT? Effect of Altitude?

[aloetard]

Any scuba diver on board?
I have always had relatively low air consumption. Dive instructors judge this as high level of experience. However, I'm a once per year recreational suba diver.
Now I thought that I might have had higher than average hematocrit before TRT and this might be a contributing factor. Anyway, couldn't find any scuba science about it.
Aloetard sparked my interest in that topic.

The following article is probably not up to date but more holistic and much less detailed than previously posted articles.

Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells

During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O[2] from the lungs to the tissues and the delivery of metabolically produced CO[2] to ...

www.ncbi.nlm.nih.gov

Thank you very much for posting this article. Excellent.

A highly increased Hct increases blood viscosity and increases the workload of the heart (El-Sayed et al., 2005; Böning et al., 2011). It therefore bears the risk of cardiac overload.

Refs above:

Haemorheology in Exercise and Training - Sports Medicine

Disruption of the normal rheological properties of blood is considered an independent risk factor for cardiovascular disease and plays a significant role in the aetiology of atherothrombogenesis. The acute increase in whole blood viscosity may unfavourably affect the microcirculatory blood flow...

link.springer.com

The Hematocrit Paradox – How Does Blood Doping Really Work?

Thieme E-Books & E-Journals

www.thieme-connect.com

See also the Hemorheology section.

Walking/sitting around all day with testosterone induced high Hct? Take a read above. If you want to roll the dice with elevated Hct, do everything in your power to keep plasma viscosity low to minimize the work your heart has to do all day/night long.

 

[Seagal]

Thank you very much for posting this article. Excellent.



Refs above:

Haemorheology in Exercise and Training - Sports Medicine

Disruption of the normal rheological properties of blood is considered an independent risk factor for cardiovascular disease and plays a significant role in the aetiology of atherothrombogenesis. The acute increase in whole blood viscosity may unfavourably affect the microcirculatory blood flow...

link.springer.com

The Hematocrit Paradox – How Does Blood Doping Really Work?

Thieme E-Books & E-Journals

www.thieme-connect.com

See also the Hemorheology section.

Walking/sitting around all day with testosterone induced high Hct? Take a read above. If you want to roll the dice with elevated Hct, do everything in your power to keep plasma viscosity low to minimize the work your heart has to do all day/night long.

As usual, that's the current state of science. Again, I'm not a proponent of high hct. Not much knowledge about the impact of weightlifting, however - you won't like it - it seems that endurance training is beneficial.

 

[aloetard]

As usual, that's the current state of science. Again, I'm not a proponent of high hct. Not much knowledge about the impact of weightlifting, however - you won't like it - it seems that endurance training is beneficial.

Sorry my last post may have been unclear. The first part was for you (sincere thanks for the paper). Second part was general comments to interested reader.

Looking into the scuba angle. Very cool.

 

[Fernando Almaguer]

Have you all any knowledge on plasma donations being beneficial for any reasons. I know they will pay you for them but I heard they can be beneficial. Probably not for HCT, although I am not sure.

 

[Seagal]

Have you all any knowledge on plasma donations being beneficial for any reasons. I know they will pay you for them but I heard they can be beneficial. Probably not for HCT, although I am not sure.

No, I only have a stupid comment: I could use some plasma to reduce my hct

 

[aloetard]

Have you all any knowledge on plasma donations being beneficial for any reasons. I know they will pay you for them but I heard they can be beneficial. Probably not for HCT, although I am not sure.

Very cool angle! You are right, the RBCs go back so not a viable Hct reduction strategy.

But regarding plasma components and blood pressure, check out this study:

The effect of plasmapheresis on blood pressure in voluntary plasma donors - PMC

Donor plasmapheresis involves the removal of a weight-adjusted volume of plasma and the return of cellular components to the donor. Although plasma volume generally returns to normal, some residual effect on vital signs may be possible. This ...

www.ncbi.nlm.nih.gov

The BP decreases observed likely do not relate to the temporary drop in blood volume since postplasmapheresis volume returns to normal levels within a short period of time. The BP changes appear highly dependent on the donor's baseline BP category, and while the possibility of some regression to the mean effect cannot be excluded, the models were intended to minimize this possibility.

The mechanism governing this postdonation BP decrease may relate to the removal of one or more molecules affecting BP levels 22–26. Studies have suggested that the use of therapeutic plasmapheresis in patients with refractory or severe malignant hypertension due to essential hypertension may reduce BP and that this reduction may relate to the removal of dialyzable molecules during plasmapheresis 22,23. The volume removed during therapeutic plasmapheresis, which can be 1·0–1·5 times a patient's total plasma volume, is much greater than the volume in a plasma donation although the frequency of therapeutic plasmapheresis is generally less than the maximum permitted plasma donation schedule. It is possible that a drop in mediators affecting BP regulation could result from multiple plasma donations following mechanisms similar to those observed during therapeutic plasmapheresis and that replacement of these factors was sufficiently slow with 5- to 7-day donation intervals to allow BP to remain lowered.

Still that's a lot of plasticizer you are getting back with the vinyl bag/tubing. Very cool proof of concept nonetheless.

Fig 1 from paper:

Figure - PMC

Donor plasmapheresis involves the removal of a weight-adjusted volume of plasma and the return of cellular components to the donor. Although plasma volume generally returns to normal, some residual effect on vital signs may be possible. This ...

www.ncbi.nlm.nih.gov

 

[aloetard]

Plasma viscosity....

COVID 19 study

Diagnostic value of plasma viscosity testing for patients with COVID‐19 - PMC

www.ncbi.nlm.nih.gov

Nutritional impact/discussion

Effect of diet on blood viscosity in healthy humans: a systematic review - PMC

Increased whole blood viscosity is associated with increased risk of morbidity and mortality of several life-threatening diseases, including cardiovascular and cerebrovascular disease. The effect of diet on human health has been indicated in many ...

www.ncbi.nlm.nih.gov

Hold the carbs and refined sugar. I am currently betting my life on modified carnivore/high protein.

According to the latest "research" my T2D (kidding) should be flaring up pretty bad:

https://www.google.com/amp/s/amp.cnn.com/cnn/2024/08/20/health/meat-red-processed-diabetes-wellness

https://www.thelancet.com/journals/landia/article/PIIS2213-8587(24)00179-7/fulltext

Lmao.

Someone forgot to tell my total cholesterol, hdl-c, trigs, and fasting glucose.

Here's a cool experiment....eat nothing but round steak for a year. Tell me how the T2D goes. Extra credit throwing in some raw spinach with it for a separate treatment arm.

 

[aloetard]

https://web.as.uky.edu/Biology/faculty/cooper/Cardiovascular%20issues-blood%20flow-%20viscosity-plaque/blood%20doping.pdf

Changes in red blood cell parameters during incremental exercise in highly trained athletes of different sport specializations

During physical exercise, the level of hematological parameters change depending on the intensity and duration of exercise and the individual’s physical fitness. Research results, based on samples taken before and after exercise, suggest that ...

www.ncbi.nlm.nih.gov

Why did the human body evolve to elevate Hct during exercise? Why would it not keep Hct higher all the time?

See Fig. 1 in first linked paper.

 

[aloetard]

Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells

During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O[2] from the lungs to the tissues and the delivery of metabolically produced CO[2] to ...

www.ncbi.nlm.nih.gov

Hematocrit not only affects the amount of O2 that can be carried per volume of blood but also affects the rheological properties of blood. Due to its composition of plasma and blood cells it behaves as a non-Newtonian fluid, whose inner viscosity is affected by the shear forces and is determined by the concentration of plasma proteins (plasma viscosity), the physico-chemical properties of the red blood cell plasma membrane (deformability) and cellular hemoglobin concentration (cytosolic viscosity), the flow velocity (aggregation), and temperature (for review see El-Sayed et al., 2005). A high blood viscosity causes a high resistance to flow, increases the power output of the heart at a given cardiac output, and might impair local blood flow.