In het onderzoek van Hoang e.a. is de effectiviteit van dierlijk schildklierhormoon (Armour) vergeleken met de effectiviteit van levothyroxine (Synthroid) bij de behandeling van patiënten met hypothyreoïdie. Clinical Thyroidology geeft commentaar. En D Rosenthal en K Hupart hebben kritiek op het onderzoek van Hoang.
Behandeling met dierlijk schildklierhormoon leidde in het onderzoek niet tot een aanzienlijke verbetering van de kwaliteit van het leven. Wel veroorzaakte de behandeling een bescheiden gewichtsverlies en bijna de helft (48,6%) van de patiënten sprak een voorkeur uit voor dierlijk schildklierhormoon boven levothyroxine. Voor sommige patiënten kan deze behandeling oplossing bieden.
Patients with hypothyroidism taking desiccated thyroid extract lost weight as compared with an equivalent dose of levothyroxine
J Hershman - Clinical Thyroidology
Behandeling met dierlijk schildklierhormoon leidde in het onderzoek niet tot een aanzienlijke verbetering van de kwaliteit van het leven. Wel veroorzaakte de behandeling een bescheiden gewichtsverlies en bijna de helft (48,6%) van de patiënten sprak een voorkeur uit voor dierlijk schildklierhormoon boven levothyroxine. Voor sommige patiënten kan deze behandeling oplossing bieden.
Reacties
(http://press.endocrine.org/e-letters/10.1210/jc.2012-4107)
David S. Rosenthal and Kenneth H Hupart
Division of Endocrinology, Nassau University Medical Center, East Meadow, New York
Originally published online on Oct. 23, 2013
Hoang et al. (1) re-examine an old question: Is there a place for animal-sourced desiccated thyroid extract (DTE) in the treatment of hypothyroidism? In the 70 patients they studied, almost half (49%) preferred DTE, and treatment with DTE was associated with a 3- to 4-pound weight loss as well as with subjective improvement in quality of life. However, no changes were found in psychometric testing. Long-standing concerns about DTE therapy have included the resultant non-physiologic T3 pharmacodynamics (2) and these have been recently re-emphasized (3). Hoang et al. (1) report that, while serum T3 levels at the end of each arm of their 16-week crossover treatment protocol drawn before the once daily dose of DTE (ie, at the expected nadir) remained within their laboratory’s reference range, there was a statistically significant increase in the mean serum T3 (50 ng/dl; P < 0.0001) in the DTE-treated group compared with the L-T4 group. They also report in their supplemental data that serum T3 levels in only two of their cohort drawn once before DTE dosing (nadir) and once again 3 hours afterwards [at or perhaps just prior to the expected peak (2)]. Patient 1 had a rise of 46 ng/dl(36%) and patient 2 had a rise of 31 ng/dl (23%), with these data also being within the nominal reference range. It is unfortunate that Hoang et al. (1) did not obtain more frequent measurements in more of their cohort at multiple times after DTE dosing, but the results they did obtain seem consistent with the nonphysiologic T3 peak and trough pharmacodynamics reported by Saberi (2) 40 years ago and by others subsequently (3). While the authors do comment upon concern for possible resulting cardiovascular side effects (but not about possible changes in bone turnover) these concerns are not noted at all in their abstract. This study valuably re-awakens an old debate, but it sheds little new light on old observations and concerns.
Sadly, the lack of any prominent discussion of non-physiologic T3 pharmacodynamics or any similarly prominent caveat about potential side effects has allowed self-styled “holistic patient advocates” and some in the popular press to suggest that this study is a breakthrough and presents a newly accepted and recommended therapy by scientific thyroidologists — which it is not and does not. A call for learned, scientific, academic discussion is laudable (3, 4), but we need to take care not to facilitate those with their own agendas to confuse patients as to the recently vetted and published ATA/AACE treatment recommendations (5).
References
Hoang TD, Olsen CH, et al. Desiccated thyroid extract compared with levothyroxine in the treatment of hypothyroidism: a randomized, double blind, crossover study. J Clin Endocrinol Metab. 2013; 98:1982–1990.
Saberi M, Utiger RD. Serum thyroid hormones and thyrotropin concentrations during thyroxine and triiodothyronine therapy. J Clin Endocrinol Metab. 1974; 39:923–927.
Biondi B, Wartofsky L. Combination treatment with T4 and T3: toward personalized replacement therapy in hypothyroidism? J Clin Endocrinol Metab. 2012; 97:2256–2271.
Hershman J. Patients with hypothyroidism taking desiccated thyroid extract lose weight as compared with an equivalent dose of levothyroxine. Clin Thyroidol. 2013; 25:122–124.
Garber JR, Cobin JH, et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by The American Association of Clinical Endocrinologists and The American Thyroid Association. Thyroid. 2012; 22:1200–1235.
Conflict of Interest: None declared.
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