How Sleep Apnea Affects Your Blood
Sleep apnea is a largely overlooked problem, and I can’t emphasize enough how important it is to address it. It causes all kinds of nasty stuff like blood sugar dysregulation, weight gain, stroke, heart attack, etc. if left unchecked. The loss of oxygen that occurs at night can have an impact on your blood markers. This means that your routine bloodwork can potentially pick up on an undiagnosed sleep apnea problem.
With the chronic sleep disruption that occurs with apnea, hypoxia occurs (low oxygen). In response to low oxygen levels, as a way to compensate, the body stimulates the production of erythropoietin, a hormone produced by the kidneys that stimulates red blood cell (RBC) production in the bone marrow. This is called polycythemia, so you’d see a rise in RBCs in your bloodwork.
Because the RBCs rise, so does hemoglobin (which is transported by RBCs). Hematocrit is the blood volume, or as I like to think of it, density; how thick your blood is. When you are dehydrated, your hematocrit rises. Since RBCs rise, so does hematocrit.
MCV stands for mean corpuscular volume. This is the average size of your blood cells. Blood cells are born large, and die smaller. Blood cells typically live about 120 days, but that can vary depending on the health of the individual. In an environment where chronic elevation of blood sugars occur (as it typically does with sleep apnea), blood cells will die younger. In other words, the higher the MCV, the sooner the blood cells are dying; so you’d expect elevated MCV with sleep apnea.
Sleep apnea has a known correlation to cardiovascular disease, largely because of its contribution to developing diabetes. So if you see these indices rising, it’s important to follow up on it and find out why these numbers are rising.
To summarize, you may see:
Elevated RBCs
Elevated Hemoglobin
Elevated Hematocrit
Elevated MCV
If you feel you need help with interpreting your bloodwork, let’s get on a call: