Wednesday, August 8, 2018

Parathyroid function, hypoparathyroidism,osteoporosis- just another day in thyroid cancer world

Everyone has four parathyroid glands. These tiny glands- usually the size of a grain of rice- have a big function. That function is calcium and phosphorus  regulation in our bodies. That is their sole purpose in life- nothing else matters to them. The parathyroid glands are located behind the thyroid gland. Even though they share part of their name with the thyroid gland, they have no connection as far as what they do for a living. The thyroid gland regulates our metabolism, while the parathyroid glands, as stated, regulate calcium and phosphorus  levels. Why is calcium regulation so important? Calcium is the element that regulates the normal conduction of electrical currents along nerves. Calcium also causes muscles to contract. In fact, this is so important that the parathyroid glands are the only glands in the body that have the sole purpose in life just to regulate the correct amount of calcium and phosphorous in our bodies. The so called normal range of calcium is from 9 to about 10. We humans do not feel well if that level drops to below 9 or rises to above 10. Phosphorus regulation is important in that too much of this can hurt our kidneys. The parathyroids  can help the kidney eliminate excess phosphorus.

The parathyroid glands regulate calcium and phosphorous levels  by producing a hormone called parathyroid hormone, or PTH as it is known by its friends. If our calcium level drops, the parathyroid glands recognize this fact, and make PTH. This PTH goes to our bones and takes out some calcium, which then goes to our bloodstream. Our bones contain the majority of calcium for our bodies. There is also some calcium  in certain cells and some in blood and extracellular fluid.  When the parathyroids feel that the calcium level in the blood is correct, they take a break and stop making PTH.  A person can get by with one parathyroid gland, but we all need at least one. There are a few causes of hypoparathyroidism, but the major cause of this, and the only one that I will discuss, is hypoparathyroidism caused by thyroid cancer surgery, which results in removal of all of our parathyroid glands.  Some symptoms of hypoparathyroidism include: 
* tingling or burning in fingertips, toes and lips
* muscles aches or cramps in feet, face, abdomen
* twitching or spasms in muscles around the mouth or in the hands, arms and throat
*fatigue, weakness
* hair loss
*dry skin
*depression or anxiety
* in severe cases, there could be seizures or difficulty breathing. 

How is hypoparathyroidism treated? The doctor monitors the blood level of calcium, phosphorus ( too much phosphorus released by the bones can cause organ damage) and PTH. Low production of PTH in hypoparathyroidism, causes abnormally low calcium  levels in the blood and bones, and increased levels of phosphorus in the blood stream. 

Along with calcium supplements, a drug , Calcitrol, can be prescribed to treat hypoparathyroidism. Calcitrol is the active metabolite of vitamin D. The ways that  it works are by increasing the calcium that is released by the gut into the bloodstream, increasing the amount of calcium that is reabsorbed by the kidneys, and probably by increasing the amount of calcium that is released into the blood stream  by the bones.

Hypoparathyroidism is treatable, but it is a life long condition and can have serious complications. This is one example of why it is so important to have an experienced surgeon  doing thyroid cancer surgery. Please, please find out how many thyroid cancer surgeries that your potential surgeon has done, read reviews, and do your homework on the surgeon's technique, including how many patients he/she has had with hypoparathyroidism after surgery. 

A condition that is related to the above mentioned material, is osteoporosis. Osteoporosis can be  caused by several factors. Increasing age, a sedentary lifestyle, low estrogen in women, low testosterone in men, a deficiency of calcium and vitamin D, and high levels of thyroid hormone, just to name a few. How is osteoporosis diagnosed? By a bone density test, which measures how many grams of calcium and other bone materials are present in a section of bone. The bones most commonly tested are the hip and spine. Dense bones are good bones! Dense bones are less likely to break. Who wants a broken hip?

A bone density test is not painful. It is a fairly fast test- completed in about 10 to 15 minutes. It is best to wear loose clothing and avoid belts, zippers, and metal objects in pockets, etc. One thing that I was not aware of, is that it is best to avoid taking calcium supplements for at least 24 hours before the test. The amount of radiation that one is exposed to is very small. Much less than a chest x-ray, and I read on one site that a central DXA machine, which is the preferred test if your insurance will pay for it, has 10-15 times less radiation than a person receives on a round trip flight from New York to San Francisco! It is also recommended to use the same site/machine for subsequent bone density tests. This provides the doctor with a more accurate comparison of the results.

And how are the results expressed? The most commonly used test result is called a T-score. It is the bone density compared to the bone density of a healthy young adult of your sex. The following is a breakdown of the T-scores:

*  T-Score of  -1 and above :    Your bone density is considered normal

*  T-score of between -1 and -2.5 :  your score is considered osteopenia, ( below normal,) 
                                                
*  T-score of  -2.5 and below : considered to be osteoporosis

It is interesting to note that having low bone density or osteopenia does not mean that you will automatically have osteoporosis. If you lose bone in the future, or if your physician determines that you have what is called " fracture risk, or the estimate of the chance of a person breaking a bone" it may be determined that you need treatment for osteoporosis. It is not easy to determine if a person with osteopenia, or mild osteoporosis needs to take a treatment medication. These treatment medications have quite a few side effects, but certainly have their place in the hopes of preventing broken bones. 

In conclusion, the  parathyroid glands are extremely important to our bodies. It is an unfortunate consequence in some cases of thyroid cancer surgery, that one loses all of the parathyroids. Regardless of how many parathyroid glands that one does or does not have, it is important to have blood calcium tested and monitored by one's physician. And furthermore , along with the standard thyroid blood tests and calcium level tests, it would be prudent to have a bone density test every year or two. Know your numbers, keep a record of your tests, and most importantly, be your own best patient advocate.    

No comments:

Post a Comment