Michele Zini Servizio di Endocrinologia - Arcispedale S. Maria Nuova, IRCCS Reggio Emilia michele.zini@asmn.re.it

1. Michele Zini
Unità Operativa di Endocrinologia
Arcispedale S. Maria Nuova IRCCS, Reggio Emilia
Michele.zini@asmn.re.it
Il selenio: un valore aggiunto ?

2. Indice
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Selenio
Selenio e tiroidite autoimmune
Selenio e m. di Graves
Selenio e gravidanza

3. Selenium
Duntas LH et al., European Journal of Endocrinology 148: 389–393, 2003
• Selenium is an essential component of the glutathione
peroxidase enzymes and of thioredoxin reductase which
protects tissues from oxidative damage
• Selenium
is
contained
in
the
iodothyronine
selenodeiodinases, D1 and D2, which are responsible for
the production of biologically active triiodothyronine via 50deiodination
• Thus, selenium deficiency may seriously influence the
generation of free radicals, the conversion of T4 to T3 and
the autoimmune process

4. Selenium in autoimmune thyroiditis
Gärtner R et al., J Clin Endocrinol Metab 87: 1687–1691, 2002
Free T4 and T3 as well as TSH values were unchanged in both groups, and
all were within the normal range.

5. Selenium in autoimmune thyroiditis
Gärtner R et al., J Clin Endocrinol Metab 87: 1687–1691, 2002
• Free T4 and T3 as well as TSH values were
unchanged in both groups, and all were within
the normal range.
• A subgroup analysis of patients with TPOAb
greater than 1200 IU/ml revealed a decrease in
antibody concentrations in this group to 60% in
the selenium group vs. an increase of 10% in
the placebo group.

6. Selenium in autoimmune thyroiditis
Gärtner R et al., J Clin Endocrinol Metab 87: 1687–1691, 2002
• A decrease in both antibody concentrations below
50 IU/ml was detected in nine patients in the
selenium-treated group vs. two patients in the
placebo group (P < 0.015).
• Improvement of ultrasound echogenicity was
observed in nine patients in the selenium-treated
group vs. two patients in the placebo group. These
were identical to those patients with a decrease in
antibody concentrations below 50 IU/ml, except for
one patient in the placebo group.

7. Selenium in autoimmune thyroiditis
Mazokopakis EE et al., Thyroid 17: 609-612, 2007
STOP selenium
treatment
Reduction (%) of the serum anti–thyroid peroxidase (TPO) levels according to
continuation (Group A) or discontinuation (Group B) of Se treatment at the second 6
months

8. Selenium in autoimmune thyroiditis
Mazokopakis EE et al., Thyroid 17: 609-612, 2007
• Our study showed a significant and
constant reduction (21%) of anti-TPO
levels in the group which received 12
months of L-selenomethionine treatment.
• There were no significant changes
between serum concentrations of TSH,
FT3, FT4, and anti-Tg during the study
period.

9. Selenium in autoimmune thyroiditis
Nacamulli D et al., Clinical Endocrinology 73: 535–539, 2010

10. Selenium in autoimmune thyroiditis
Nacamulli D et al., Clinical Endocrinology 73: 535–539, 2010

11. Selenium in autoimmune thyroiditis
Nacamulli D et al., Clinical Endocrinology 73: 535–539, 2010
There was no significant difference between the two groups at any
follow-up point.

12. Selenium in autoimmune thyroiditis
Karanikas G et al., Thyroid 18: 7-12, 2008

13. Selenium in autoimmune thyroiditis
Anastasilakis AD et al., Int J Clin Pract 66: 378–383, 2012
A prospective, open-label, quasirandomised
study
in
86
Hashimoto thyroiditis patients
assigned
to
either
selenomethionine 200 µg daily
for 3 months (Seme 3, n = 15) or
6 months (Seme 6, n = 46) or
placebo (Controls, n = 25).
Anti-TPO levels were not significantly altered
pharmacological doses of Seme for 6 months.
by

14. Selenium in autoimmune thyroiditis
Duntas LH, J Clin Endocrinol Metab 95: 5180–5188, 2010

15. Selenium in autoimmune thyroiditis
Duntas LH, J Clin Endocrinol Metab 95: 5180–5188, 2010
• Selenium supplementation has positive effects in regions
of both selenium deficiency and sufficiency
• This supports to the hypothesis that the result comes
about via pharmacological actions, rather than a correction
of selenium deficiency
• The lower the selenium levels, the higher the efficacy of
treatment
• The higher the amount of anti-TPO, the better the
outcome of treatment in terms of reduction of anti-TPO
concentration.

16. Selenium in autoimmune thyroiditis
Toulis KA, Thyroid 20: 1163-1173, 2010

17. Selenium in autoimmune thyroiditis
Toulis KA, Thyroid 20: 1163-1173, 2010
• Although selenium decreases TPOAb titers, the lack of
outcomes with direct clinical implications should be underlined
• TPOab titers are considered as a surrogate marker, an
intermediate outcome of limited clinical importance in the course
of Hashimoto’s thyroiditis, with the exception of pregnancy
• Thus, meaningful clinical outcomes should be demonstrated
before Se supplementation can be routinely recommended:
• reducing the progression rate from euthyroidism to
subclinical hypothyroidism
• reducing the progression rate from subclinical to overt
hypothyroidism
• reducing the need of thyroxine treatment

18. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

19. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

20. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

21. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

22. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

23. Selenium and Graves’ ophtalmopathy
Marcocci C et al., N Engl J Med 364:1920-31, 2011

24. Selenium in pregnancy
Negro R et al., J Clin Endocrinol Metab 92: 1263–1268, 2007

25. Selenium in pregnancy
Negro R et al., J Clin Endocrinol Metab 92: 1263–1268, 2007