Titre du document / Document title

Impact of thyroid dysfunction on serum cystatin C

Auteur(s) / Author(s)

FRICKER Manuel ; WIESLI Peter ; BRÄNDLE Michael ; SCHWEGLER Beat ; SCHMID Christoph ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

Department of Internal Medicine, Division of Endocrinology and Diabetes, University Hospital of Zurich, Zurich, SUISSE
Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, ETATS-UNIS

Résumé / Abstract

Background. Serum cystatin C (CysC) is a novel marker for kidney function that has been claimed to be superior to serum creatinine. Thyroid dysfunction may alter creatinine, which has been found to be increased in hypothyroidism and decreased in hyperthyroidism. This study was performed to evaluate whether changes in CysC and creatinine are parallel during the treatment of hypo- and hyperthyroidism, respectively. Methods. Prospective case series of 22 consecutively referred patients with thyroid dysfunction. Creatinine and CysC were determined at the time of diagnosis of hypo- and hyperthyroidism, and when free thyroxine (fT4) returned into the normal range. Hypothyroid patients were treated with levothyroxine. Hyperthyroid patients were treated with antithyroid drugs, surgery, or radioiodine. Results. Nine patients with hypothyroidism and 13 patients with hyperthyroidism were included. In patients with hypothyroidism mean fT4 (±SD) was 4.9 ± 2.5 pmol/L (reference, 12 to 22) at diagnosis and increased to 16.6 ± 1.6 pmol/L when patients were treated with levothyroxine. Creatinine decreased from 86 ± 13 μmol/L (reference. 70 to 105) in the hypothyroid state to 76 ± 16 μmol/L when fT4 normalized (P = 0.062), whereas CysC increased from 0.84 ± 0.17 mg/L (reference, 0.63 to 1.33) to 1.1 ± 0.28 mg/L (P < 0.001). In patients with hyperthyroidism, mean fT4 was 54.6 ± 22.7 pmol/L (reference, 12 to 22) at diagnosis and decreased to 15.8 ± 3.6 pmol/L following treatment with antithyroid drugs, thyroid surgery, or radioiodine. Creatinine increased from 67 ± 15 μmol/L at diagnosis of hyperthyroidism to 75 ± 9 μmol/L when tT4 normalized (P = 0.004), whereas CysC declined from 1.32 ± 0.17 mg/L to 0.95 ± 0.19 mg/L (P < 0.001). Conclusion. Thyroid dysfunction has a major impact on CysC levels. Therefore, thyroid function has to be considered when CysC is used as a marker of kidney function. In contrast to creatinine concentrations, CysC levels are lower in the hypothyroid and higher in the hyperthyroid state as compared with the euthyroid state.

Revue / Journal Title

Kidney international   ISSN 0085-2538   CODEN KDYIA5 

Source / Source

2003, vol. 63, n^o5, pp. 1944-1947 [4 page(s) (article)] (17 ref.)

Langue / Language

Anglais

Editeur / Publisher

Nature Publishing, New York, NY, ETATS-UNIS  (1972) (Revue)

Mots-clés anglais / English Keywords

Aminoacid derivative hormone ; Thyroid hormone ; Thyroid diseases ; Endocrinopathy ; Human ; Statistical analysis ; Prospective ; Influence ; Creatinine ; Thyroxine ; Hyperthyroidism ; Hypothyroidism ; Blood plasma ; Cystatin ;

Mots-clés français / French Keywords

Hormone aminoacide dérivé ; Hormone thyroïdienne ; Thyroïde pathologie ; Endocrinopathie ; Homme ; Analyse statistique ; Prospective ; Influence ; Créatinine ; Thyroxine ; Hyperthyroïdie ; Hypothyroïdie ; Plasma sanguin ; Cystatine ;

Mots-clés espagnols / Spanish Keywords

Hormona aminoácida derivado ; Hormona tiroidea ; Tiroides patología ; Endocrinopatía ; Hombre ; Análisis estadístico ; Prospectiva ; Influencia ; Creatinina ; Tiroxina ; Hipertiroidismo ; Hipotiroidismo ; Plasma sanguíneo ; Cystatina ;

Mots-clés d'auteur / Author Keywords

: serum cystatin C. thyroid dysfunction ; creatinine ;

Localisation / Location

INIST-CNRS, Cote INIST : 15906, 35400011255958.0400