cystic fibrosis and hypothyroidism

Question

Hello,
Since the time our daughter has been diagnosed with CF (del F508 del F508), problems with thyroid gland has appeared (it has been lasting for more than 5 years). We check the hormone's levels every 2-3 months according our doctor's suggestion and every time the results are not satisfying, which means they are above the reference range (I should mark that hormone preparation is always given in fasting state, ca 1/2 hour before meal). Every time we visit endocrinologist he increases the dose (now our daughter recives 50 mcg of Letrox every day). The doctor suggested us, that maybe this is our "fault"and the child is not receiving the drug regularly. We do obey the treatment regime and we never missed the dose. In our daughter also anti-thyroid antibodies were assessed and the results are also bad (marginally). The doctor, who is taking care of our daughter, suggested that we should visit another doctor. We did it, another tests were done and this time the dose is increased again. We understand, that the child grows, gains weight and maybe the thyroid gland "is not coping" with this, but nobody can tell us, why this happens. Can cystic fibrosis influence the thyroid gland and is it possible, that the drugs our daughter receives every day somehow disturb the action of iatrogenic hormone? Should any additional tests be done? I am waiting for the answer, best regards.

Answer

Hello,
Your question contains too few details concerning the thyroid gland disease in your daughter, which are necessary to answer it in a satisfactory way. We do not know exactly, what kind of disease was diagnosed, we can only assume (on the basis on the drug recommended) this is hypothyroidism. We do not know the results of the hormonal tests and what kind of autobodies were detected in your daughter. We also do not know, how the drug is administered to your daughter, maybe the treatment is not effective, because the drug is not administered properly.
To clear all doubts, we advise a complex endocrinologic assessment in your daughter.
In order to do this you can contact the Dept. of Pediatric Endocrinology and Rheumatology, Poznań University of Medical Sciences, 27/33 Szpitalna Str., 60-572 Poznań.Tel./fax. 61 8480 291, 61 8491 481. Head of the Dept.: prof. UM dr hab. Marek Niedziela.
With kind regards,
prof. dr. hab. Wojciech Cichy
dr n.med. Natalia Kobelska-Dubiel
(counseling: prof. UM dr hab. Marek Niedziela)

10.05.2011

10.5.11
As it is written in the answer, we do not know which kind of illness affects the thyroid gland, it seems to be hypothryreoidism, probably Hashimoto thyreoidits in case certain autoantibodies are positive. In this disease, autoantibodies destroy the thyroid gland, it proceeds slowly, so that in the course of time less and less hormone is produced by the gland and the need for substituional hormones increases. Therefore the hormone dosage has to be adjusted individually according to the laboratory findings. Other cirumstances like special kinds of gastritis could also lead to a higher need of hormones. Taking the hormones 30-60 minutes before the morning meal is correct as described in the question.

In the literature, there could not be found any data about an increased coincidence of hashimoto-thyreoiditis (if we are talking about one in this case at all) and CF, whereas other autoimmune diseases like celiac disease are more frequent in patients with CF. So there is no direct correlation or interaction between CF and an assumed Hashimoto thyreoiditis, for interaction of different drugs please study intensively the instruction leaflet to find out, how to avoid interactions.
D. d'Alquen