I just saw Kim (name changed for privacy), who is a 24 year old graduate student for her recurrent sinus infections. She tried multiple antibiotics which helped only temporarily. She also mentioned that she was chronically tired, which she blamed on her anemia. As I see in many women (and men) with upper airway resistance syndrome, she also had frequent headaches, cold hands and feet, low blood pressure, and cannot sleep on her back.
One of the most common explanations by doctors for fatigue in younger women is said to be from anemia. It’s thought that losing regular amounts of blood during the normal menstrual cycle can lower blood count levels. There are a number of other explanations for anemia, including Vitamin B12 and folate deficiency.
One of my guest bloggers, Dr. Deborah Wardly, recently published a review article a few years back on the effects of atrial natriuretic peptide (ANP) on various aspects of your body. ANP is created in your heart muscles every time it’s subjected to obstructed breathing. The heart thinks that the body has too much fluid, and creates ANP which goes to the kidneys to create more urine, lowering blood volume. She also points out that ANP has been shown to lower your blood pressure, keep you thin, make your nervous system more excitable, make you chronically tired, and makes you pee more than usual. In particular, ANP is also known to lower the angiotensin-aldosterone pathway in the kidneys.
So how does lowering angiotensin-aldosterone cause anemia? A quick review of the renin-angiotensin-aldosterone system (RAAS) is in order. I know it sounds a bit complicated, but take a look at the referenced figures, and you’ll see how everything in the body is so well interconnected.
The RAAS is a hormone system that regulates blood pressure and fluid balance. If the kidneys sense that you’re dehydrated (lower blood flow through the kidneys), the cells in your kidneys convert an already circulating protein (prorenin) into renin, which converts angiotensinogen (made by the liver) into angiotensin I. Angiotensin I is then converted into angiotensin II by angiotensin converting enzyme (ACE) in the lungs. Angiotensin II constricts your blood vessels, raising your blood pressure. It also stimulates the hormone aldosterone, which is made in the adrenal cortex (which also makes epinephrine). Aldosterone causes the kidneys to reabsorb sodium and water, causing you to hold onto sodium, raising your blood pressure.
As you can see in this diagram, there are a number of steps that can be blocked by certain prescription medications.
ANP has the opposite effect of angiotensin II, lowering renin and aldosterone in the kidneys. One review article states that angiotensin II acts to stimulate erythropoietin, which is made in the kidneys to stimulate red blood cell production in your bone marrow. So by lowering the salt and fluid conserving properties of angiotensin II, you can in theory lower erythropoietin levels. This supports the observation that you can have mild anemia if you’re taking ACE inhibitors for high blood pressure or in certain people with chronic kidney disease. Now you can add upper airway resistance syndrome to the list (via ANP production).
If you have been diagnosed with anemia, do you also have cold hands, low blood pressure, headaches or chronic fatigue? Do you also prefer to sleep on your side or stomach? Please tell us your story in the box below.