correspondence
n engl j med 355;11 www.nejm.org september 14, 2006 1177
Thyroxine in Goiter, H. pylori Infection, and Gastritis
To the Editor: Centanni et al. (April 27 issue)1
describe conditions influencing the resorption of
thyroxine and conclude that gastric acidity has a
considerable effect on the bioavailability of iodo-
thyronines. We do not share this opinion. In a re-
cent crossover trial with healthy participants,2 we
demonstrated that therapy with a high-dose pro-
ton-pump inhibitor (pantoprazole, 40 mg per day),
resulting in elevated gastrin levels 1 week before
the administration of thyroxine, did not influence
absorption kinetics. The mechanisms of iodothy-
ronine resorption are not fully understood, but
malabsorption may be caused by numerous fac-
tors, including inflammatory diseases.3 In this
context, it should be pointed out that all groups
of patients studied by Centanni and colleagues
and noted to have elevated gastric pH (those with
atrophic gastritis, those with Helicobacter pylori in-
fection, and those with gastroesophageal reflux)
also had gastrointestinal inflammation. There-
fore, we believe their study does not conclusively
identify gastric acidity as a major determinant of
thyroxine resorption.
Johannes W. Dietrich, M.D.
Bergmannsheil Hospitals
D-44789 Bochum, Germany
Bernhard O. Boehm, M.D.
Ulm Medical University Hospital
D-89081 Ulm, Germany
bernhard.boehm@uniklinik-ulm.de
Centanni M, Gargano L, Canettieri G, et al. Thyroxine in goi-
ter, Helicobacter pylori infection, and chronic gastritis. N Engl J Med
2006;354:1787-95.
Dietrich JW, Gieselbrecht K, Holl RW, Boehm BO. Absorp-
tion kinetics of levothyroxine is not altered by proton-pump in-
hibitor therapy. Horm Metab Res 2006;38:57-9.
Hays MT. Thyroid hormone and the gut. Endocr Res 1988;
14:203-24.
To the Editor: We would like to see the results
of basal and stimulated acid output for the pa-
tients in the study by Centanni et al. Without such
information, their conclusion that absorption of
thyroxine is dependent on gastric acid secretion
seems questionable.
Kirstin M. Taylor, M.B., B.S.
Guy Sisson, M.B., B.S.
Adam W. Harris, M.D.
Kent and Sussex Hospital
Tunbridge Wells, Kent TN4 8AT, United Kingdom
kirstin.taylor@nhs.net
1.
2.
3.
The Authors Reply: With regard to the com-
ments by Dietrich and Boehm, our findings are not
directly comparable with theirs.1 They examined
the effect on acid inhibition of 40 mg of panto-
prazole per day for 1 week in healthy euthyroid
subjects. That model is quite different from one
in which patients with thyroid disease received
long-term treatment with omeprazole at a dose
of 40 mg per day. Indeed, we are not surprised that
Dietrich and colleagues did not observe any mod-
ification in thyroxine absorption after 7 days of
treatment, since as we reported in our study, only
after 6 months of omeprazole treatment was the
dose of thyroxine increased to achieve low levels
of serum thyrotropin. Furthermore, as Dietrich
et al. stated in their article, thyroxine absorption
in subjects with healthy thyroid glands may dif-
fer from that in patients with thyroid disease.1
Regarding the request of Taylor et al., basal
acid output and pentagastrin-stimulated acid out-
put were part of the diagnostic workup in pa-
tients with atrophic gastritis. In fact, these pa-
tients had a median basal acid output of 0 mEq
per hour (range, 0 to 2.4) and a median pentagas-
trin-stimulated acid output of 0 mEq per hour
(range, 0 to 10.5). These values indicated the pres-
ence of hypochlorhydria and achlorhydria, since
both values were below our laboratory’s normal
ranges for basal acid output (median, 4.1 mEq per
hour [range, 1.2 to 11.1]) and pentagastrin-stimu-
lated acid output (median, 31.1 mEq per hour
[range, 13 to 44.4]).2,3 Thus, we believe that these
data support the hypothesis that reduced gastric
acid secretion impairs effective absorption of
thyroxine in patients with atrophic gastritis.
Bruno Annibale, M.D.
Marco Centanni, M.D.
Gianfranco Delle Fave, M.D.
University La Sapienza
00161 Rome, Italy
marco.centanni@uniroma1.it
Dietrich JW, Gieselbrecht K, Holl RW, Boehm BO. Absorp-
tion kinetics of levothyroxine is not altered by proton-pump in-
hibitor therapy. Horm Metab Res 2006;38:57-9.
Annibale B, Marignani M, Azzoni C, et al. Atrophic body gas-
tritis: distinct features associated with Helicobacter pylori infec-
tion. Helicobacter 1997;2:57-64.
Marignani M, Delle Fave G, Mecarocci S, et al. High preva-
lence of atrophic body gastritis in patients with unexplained
microcytic and macrocytic anemia: a prospective screening study.
Am J Gastroenterol 1999;94:766-72.
1.
2.
3.
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