Nelson Vergel
Founder, ExcelMale.com
Hematocrit may stabilize after long term testosterone replacement
Although this study was done in mice, it may explain why hematocrit may eventually decrease and stabilize in men on TRT. I am one of those men who only went for therapeutic phlebotomy twice. There seems to be an adaptive mechanism that makes red blood cells get change form while hematocrit stabilizes.
Guo W, Bachman E, Vogel J, Li M, Peng L, et al. The Effects of Short-Term and Long-Term Testosterone Supplementation on Blood Viscosity and Erythrocyte Deformability in Healthy Adult Mice. Endocrinology.http://press.endocrine.org/doi/abs/10.1210/en.2014-1784
Testosterone treatment induces erythrocytosis that could potentially affect blood viscosity and cardiovascular risk. We thus investigated the effects of testosterone administration on blood viscosity and erythrocyte deformability using mouse models.
Blood viscosity, erythrocyte deformability, and hematocrits were measured in normal male and female mice, as well as in females and castrated males after short-term (2-weeks) and long-term (5-7 months) testosterone intervention (50 mg/kg, weekly).
Castrated males for long-term intervention were studied in parallel with the normal males to assess the effect of long-term testosterone deprivation. An additional short-term intervention study was conducted in females with a lower testosterone dose (5 mg/kg).
Our results indicate no rheological difference among normal males, females, and castrated males at steady-state.
Short-term high dose testosterone increased hematocrit and whole blood viscosity in both females and castrated males. This effect diminished after long-term treatment, in association with increased erythrocyte deformability in the testosterone-treated mice, suggesting the presence of adaptive mechanism.
Considering that cardiovascular events in human trials are seen early after intervention, rheological changes as potential mediator of vascular events warrant further investigation.
Definition of Erythrocyte deformability
I have seen how in some men red blood cell indices (MCV and MCHC) start changing after starting TRT as a way for the body to compensate for the extra production of red blood cells.
Red blood cell indices: There are three red blood cell indices: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). They are measured by a machine, and their values come from other measurements in a CBC. The MCV shows the size of the red blood cells. The MCH value is the amount of hemoglobin in an average red blood cell. The MCHC measures the concentration of hemoglobin in an average red blood cell. These numbers help in the diagnosis of different types of anemia. Red cell distribution width (RDW) can also be measured which shows if the cells are all the same or different sizes or shapes.
Although this study was done in mice, it may explain why hematocrit may eventually decrease and stabilize in men on TRT. I am one of those men who only went for therapeutic phlebotomy twice. There seems to be an adaptive mechanism that makes red blood cells get change form while hematocrit stabilizes.
Guo W, Bachman E, Vogel J, Li M, Peng L, et al. The Effects of Short-Term and Long-Term Testosterone Supplementation on Blood Viscosity and Erythrocyte Deformability in Healthy Adult Mice. Endocrinology.http://press.endocrine.org/doi/abs/10.1210/en.2014-1784
Testosterone treatment induces erythrocytosis that could potentially affect blood viscosity and cardiovascular risk. We thus investigated the effects of testosterone administration on blood viscosity and erythrocyte deformability using mouse models.
Blood viscosity, erythrocyte deformability, and hematocrits were measured in normal male and female mice, as well as in females and castrated males after short-term (2-weeks) and long-term (5-7 months) testosterone intervention (50 mg/kg, weekly).
Castrated males for long-term intervention were studied in parallel with the normal males to assess the effect of long-term testosterone deprivation. An additional short-term intervention study was conducted in females with a lower testosterone dose (5 mg/kg).
Our results indicate no rheological difference among normal males, females, and castrated males at steady-state.
Short-term high dose testosterone increased hematocrit and whole blood viscosity in both females and castrated males. This effect diminished after long-term treatment, in association with increased erythrocyte deformability in the testosterone-treated mice, suggesting the presence of adaptive mechanism.
Considering that cardiovascular events in human trials are seen early after intervention, rheological changes as potential mediator of vascular events warrant further investigation.
Definition of Erythrocyte deformability
I have seen how in some men red blood cell indices (MCV and MCHC) start changing after starting TRT as a way for the body to compensate for the extra production of red blood cells.
Red blood cell indices: There are three red blood cell indices: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). They are measured by a machine, and their values come from other measurements in a CBC. The MCV shows the size of the red blood cells. The MCH value is the amount of hemoglobin in an average red blood cell. The MCHC measures the concentration of hemoglobin in an average red blood cell. These numbers help in the diagnosis of different types of anemia. Red cell distribution width (RDW) can also be measured which shows if the cells are all the same or different sizes or shapes.
