In Treatment of Hypothyroidism Need For T4 plus T3 Therapy Could Be Genetic

Do you wonder if you need t3 (Cytomel, triiodothyronine, liothyronine) added to your thyroid hormone treatment to feel normal again? The answer could be in your genes.

Recent discoveries reviewed by Antonio C. Bianco, M.D., Ph.D. at the recent American Thyroid Association meeting, reveal how genetic differences influence the effectiveness of thyroid hormone replacement. Dr. Bianco’s lecture focused on studies pinpointing inborn differences in the way people metabolism thyroid hormone to explain why t3 treatment of hypothyroidism is probably required by some to restore normal functioning of their brain, muscle and heart.

The most frustrating problem for people with hypothyroidism is being unable to convince their doctor that treatment with Synthroid, Levoxyl or similar pure t4 product, isn’t working. Continued symptoms of fatigue, weakness, inability to concentrate or think clearly, and inability to lose weight despite really trying, result in tension between the doctor and the “complainer”. When assessing the adequacy of thyroid hormone replacement therapy most doctors rely on the blood tests known as the Thyroid Function Panel. Typically this includes a measurement of t4, t3, t3RU, and TSH. Some panels may also include free t4 or free t3 measurements. If the hormone levels on these tests are “within normal limits” the doctor will often insist that the treatment is a success but it is the patient who fails to recognize this. A minority of endocrinologists know many of these “failures” can be turned into success by the addition of t3, the less utilized but much more powerful form of thyroid hormone.

Most of the biological effects of thyroid hormone in the body are due to the action of t3. The most common forms of thyroid hormone replacement however, involve giving t4 in the form of Synthroid, Levoxyl, levothyroxine etc. The t3 required by our tissues is produced by specific enzymes which convert t4 to t3 in the cells of the liver, kidney, brain, muscle, heart etc. These converting enzymes are known as deiodinases and under normal conditions they are responsible for about 80% of the body’s t3. The process
by which t3 is produced from t4 is known as peripheral conversion.

It has long been the contention of the leaders in thyroid disorders that based on their arithmetic, t4 replacement is sufficient to provide all the t3 the body needs via peripheral conversion and giving t3 supplementation doesn’t make good medical sense. Now, based on the new information provided by researchers like Dr. Bianco, the “arithmetic guys” will, in my opinion, need to revise their thinking finally allowing the way for acceptance of t3 replacement approaches.

I will continue the explanation of the new breakthrough in genetic control of thyroid hormone replacement treatment in Part 2 of this post.

Facebook Tweet Pin Email LinkedIn

Unmasking the Dark Side of the Ozempic Craze

By Gary M. Pepper, M.D. Ozempic, Rybelsus, Trulicity, Wegovy, Saxenda are the central players in the weight loss craze sweeping across the globe. Metabolisim.com has been monitoring this phenomenon from its beginnings in 2008 with its report “Lizard Spit Reduces Blood Sugar and Appetite”, regarding the first drug in this class, Byetta (exenatide). Caught In the middle of the current chaos are the medical experts who treat diabetes and have been prescribing these medications for more than a decade. Here is a brief commentary from one such board certified endocrinologist; “I started treating Type 2 diabetics with GLP-1 agonists more than 10 years ago. In some respects, these medications have revolutionized the treatment of diabetes by lowering blood sugar effectively and promoting weight loss at the same time, a unique combination of benefits. Not everyone benefits from these drugs to the same degree unfortunately, and I have seen lots of patients experience unacceptable side effects from them. Nothing though, has prepared me for what is happening now. Too often, I find myself confronting someone who expects me to prescribe one of these drugs just so they can lose weight. Sadly, one extreme example was someone who, despite battling a life threatening medical condition, was insistent on getting a prescription. At the same time my diabetic patients are scrambling to find a place to buy their medications if they can even afford it. It is disheartening, to say the least, and I dread the negative interactions with some of my patients I now face almost daily.”

Off- Label Use

The FDA is the U.S. government’s department tasked with evaluating and approving drugs for specific medical conditions. When a new medication is approved for treating a medical condition by the FDA the agency will, at the same time, set strict guidelines for exactly which patients may use the newly approved drug. When a medication is used “off-label” it means that these limitations are being overridden by the provider for a potential benefit which outweighs the drugs risks. It is a general misconception that off-label means illegal; it does not. This practice has been going on for ages and more than 20% of prescriptions in the United States are prescribed off-label. A common example is the use of beta-blockers (approved for heart problems) for the treatment of performance anxiety.

GLP-1 agonist drugs, as discussed recently by metabolism.com. were originally approved for the treatment of Type 2 diabetes in adults. In the past few years most of these same medications have gained unprecedented popularity for their “off-label” weight loss benefit. Of the 5 GLP-1 agents presently in U.S. pharmacies only Wegovy (semaglutide) and Saxenda (liraglutide) are FDA approved for treating obesity. Of these two, Wegovy is the newer and had been much more popular that its sister drug Saxenda, probably due to being dosed only once weekly compared to daily for Saxenda and less likely to cause side effects. Due to Wegovy’s soaring popularity, its manufacturer, Novo Nordisk, increased the price of Wegovy two times since its initial release.