Affiliations: Operative Unit of Endocrinology, Catholic University,
Rome, Italy | Respiratory Physiology Department, Catholic
University, Rome, Italy | Institute of Biochemistry, University "Politecnico
delle Marche", Ancona, Italy
Note: [] Address for correspondence: A. Mancini, Operative Unit of
Endocrinology, Catholic University School of Medicine, Rome, Italy. E-mail:
[email protected]
Abstract: In previous works we demonstrated an inverse correlation between
plasma Coenzyme Q 10 (CoQ10) and thyroid hormones; in fact, CoQ10 levels in
hyperthyroid patients were found among the lowest detected in human diseases.
On the contrary, CoQ10 is elevated in hypothyroid subjects, also in subclinical
conditions, suggesting the usefulness of this index in assessing metabolic
status in thyroid disorders. On the other hand, a low-T3 syndrome, due to
reduced peripheral conversion from the prohormone T4, is observed in different
chronic diseases: this condition is considered an adaptation mechanism, usually
not to be corrected by replacement therapy. In order to perform a metabolic evaluation, we have studied a group
of 15 patients, aged 69–82 ys, affected by chronic obstructive pulmonary
disease (COPD), comparing respiratory indexes, thyroid hormones and CoQ10
levels (also normalized with cholesterol levels) in patients with low (group A)
or normal (group B) free-T3 (FT3) concentrations. We found that CoQ10 levels
were significantly higher in patients of group A than in B (0.91± 0.03
vs 0.7 ± 0.04 μg/ml respectively); the same difference
was observed when comparing the ratios between CoQ10/cholesterol in the two
groups (200.16 ± 8.96 vs 161.08 ± 7.03 nmol/mmol
respectively). These preliminary data seem to indicate that low T3 levels are
accompanied by metabolic indexes of a true hypothyroidism in COPD patients.
Whether this datum supports the need to perform a replacement therapy in such a
condition requires further studies.
