In the July/August ’05 issue of Endocrine Practice, an
influential journal read by endocrinologists throughout the United States, researchers again tackled the question of whether
treating hypothyroidism (underactive thyroid) with a combination of conventional t4 therapy (Synthroid, Levoxyl, levothyroxine)
along with t3 (Cytomel) was superior to using t4 alone. In my opinion this study was a fumble. It failed to show that the
addition of t3 to conventional t4 improved the level of fatigue or depression of the hypothyroid patients studied.
What could have gone wrong, I asked myself? Having recently reviewed a previous study
that failed to show improvement with combination therapy, I was sure the next set of researchers were going to get it right.
Why do I feel so confident of a positive effect of t3 on patients with hypothyroidism? It is because so many patients of mine
and my colleagues who are still suffering with symptoms of hypothyroidism on t4 treatment alone, have shown impressive
improvement when t3 was added. How could this benefit have been missed by dedicated researchers again?
As I mentioned, in a previous review of a study of combination therapy that showed
negative results I pointed out the deficiencies in the research that resulted in that misstep for science. Could the same
research errors have occurred in the new study, I wondered? Sadly, the answer is probably yes.
What exactly went wrong here? First and I think most importantly, the researchers studied patients with hypothyroidism
regardless of whether they had complaints of fatigue or depression. How, I ask, is it possible to measure improvements in
fatigue and depression in people who don’t have those complaints? If I studied the effect of an acne cream on those who didn't
have acne doesn’t it make sense that the study would show that the cream didn’t cause an improvement in pimples. So it is with
this study. If it ain’t broke, how are you going to fix it? What is most aggravating is that this
was the same approach of studying patients without symptoms taken by the previous study.
Another big problem was that when the researchers in this study added t3 to the t4 they unintentionally made these patients
more hypothyroid by failing to give enough of the thyroid medication. If you ask me this should have disqualified the study
right then and there. How can you study the benefits of thyroid hormone therapy of any type if you make the patients worse then
when they started? I rest my case.
I suppose we just have to wait for our research scientists to discover what they are doing wrong in their studies of
hypothyroidism, before they can get it right. Hopefully doctors treating hypothyroidism will maintain an open mind about the
subject until then.
Note: t3, brand name Cytomel, is a prescription drug. Only a patient and their physician can decide if using t3
is an advisable choice.
