Gettysburg Medical News
 The Clinical View
 by P.E. Hoffsten, M.D.
 2 March 2005

HYPOTHYROIDISM

            The lady was 55 years old and came to the clinic because she just didn’t feel good. Her daughter accompanied her relating that her mother had simply gotten so slow lately and didn’t seem to have any energy.  Daughter noted that her mom’s voice had gotten much deeper and wasn’t even recognizable on the phone anymore.  On examination, the lady had very coarse, dry skin.  Her hair had become much thinner than it was in the past.  Her heartbeat was only 52 times a minute.  Looking back in the clinic chart, it was seen that her heartbeat had been normal in the 70 beat-per minute level several years ago.  It was noted that the lady’s reflexes were very slow and her voice was very deep, almost male like.  The lady’s skin was puffy on physical exam and it was noted that her weight had increased about 8 pounds in the past two years.

            Even a second year medical student could look at this woman and diagnose her as having hypothyroidism.  To break that word down, “hypo” – not enough of or low function.  “Thyroid” refers to a gland in the neck that produces a hormone called thyroxin.  Thyroxin is the hormone that governs our speed and how fast we are able to burn calories.  With not enough, the person tends to function very slowly with easy fatigue.  Thus, hypothyroidism denotes not having enough thyroid hormone.  The causes of this problem almost always relates to the person becoming allergic to their own thyroid gland.  The condition fades in over several years time often happening so slowly that the person isn’t really aware that anything is going wrong.

            Treating the person with hypothyroidism simply requires replacing the right amount of thyroid hormone for that person.  The replacement amount will generally be between 50 and 300 mcg per day. (0.05-3 mg per day).  A normal person generally makes about 300 mcg of thyroid hormone for themselves each day.  So more than that is really ever a useful step in care and can be harmful.

            The trick become figuring out just how much thyroid the individual person needs and which preparation to use.  Years ago, Armour (the ones that make hot dogs) produced a product called Armour thyroid.  That product is still available on the market today.  However, the potency of the preparation is highly variable and would not be a favored method of therapy on today’s treatment programs.  Basically, what the Armour company did was take the thyroid glands out of slaughtered cattle or hogs, grind them up and press them into a pill.  Over or under shooting dosages with this preparation was common.

            Years ago, the pure thyroid hormone from the beef thyroid gland was isolated and eventually purified into a product called Levothyroxine.  Initially, it was sold on the market under the brand name Synthroid.  Like all brand name products, it was substantially more expensive than the generic products that subsequently followed.

            Not popularly known or understood is the sensitivity of thyroid hormone.  It will degenerate when exposed to light or if exposed to moisture or to heat.  Unfortunately, at which rate different preparations degenerate is different also.  Thus, while there are now several generic products on the market, it is recommended that if a person is going to use a generic, they use the same one all the time.  Unfortunately, pharmacists can switch from one generic to another when the products are “A B” rated by the FDA.  There have been protests by the American Society of Endocrinology against this practice but the FDA has not changed their stance to this time.

            In summary, a person can use a generic but it needs to be the same company’s generic rather than switching different generics back and forth.  The way one tells that the amount of thyroid replacement is correct is to have a test called the “TSH” level.  This stands for thyroid stimulating-hormone level.  Thyroid-stimulating hormone is the product made by the pituitary gland to orchestrate the function of the thyroid gland.  When the TSH level is too high, that means that the thyroid supplement is not enough.  When the TSH level gets too low, it means that the thyroid supplement is too much.  In addition to monitoring TSH levels when the person is taking thyroid hormone, it is important to monitor the cholesterol levels at least once a year. This will show if their cholesterol is well controlled.  Hypercholesterolemia is one of the problems with patients that do not have enough thyroid.  Hypothyroidism causes hypercholesterolemia.

            As a last note, many patients come to the clinic with weight problems thinking that they don’t have enough thyroid hormone and that they need a supplement.  Patients are generally aware that the thyroid hormone is a “bit of an upper”.  As such, people believe that if they take extra thyroid hormone it will help burn off some of their excess weight.  The merit of the idea would seem to be good but the fact of the situation is that it just doesn’t work.  It is very rare that a person has weight gain secondary to not producing enough thyroid.

            The healthcare providers at your local clinics are well aware of these problems and can help in adjusting a person’s thyroid needs whether they are high or low.