Protein and Lipid Concentrations in Patients with Differentiated Thyroid Cancer Treated with Radioactive Iodine-131 / Koncentracija Proteina I Lipida Kod Pacijenata Sa Diferentovanim Karcinomom Štitaste Žlezde Koji Su Lečeni Radioaktivnim Jodom-131

Short-term, overt hypothyroidism in patients with differentiated thyroid cancer (DTC) before radioiodine (131-I) therapy might be accompanied by a number of metabolic changes, including altered protein and lipid metabolism. Protein concentrations and their relationship to lipids in the serum of DTC patients have not been fully elucidated. The aim of our study was to evaluate the protein and lipid concentrations in 24 DTC patients before and 3 and 7 days after 131-I therapy compared with those of 20 healthy control subjects. After radioiodine therapy, the mean protein concentration (78.71 ± 6.71 g/L vs. 87.16 ± 6.04 g/L; p = 0.003) and cholesterol level (8.12 ± 2.13 mmol/L vs. 8.84 ± 2.09 mmol/L; p = 0.001) were lower 3 days after therapy; this persisted up to 7 days after therapy, whereas triglyceride concentrations were higher 3 days after therapy (2.44 ± 1.07 mmol/L vs. 2.26 ± 1.08 mmol/L; p = 0.041) and returned towards the pretreatment values at 7 days after 131-I therapy. There was an indirect correlation between the protein and triglyceride concentrations 3 days after 131-I therapy in patients over 50 years old (Spearman’s r = - 0.583, p = 0.048) but not in patients under 50 years old (Pearson’s r = - 0.277, p = 0.384). Radioiodine therapy of DTC patients led to decreased serum protein and cholesterol concentrations, accompanied by increased triglyceride levels; these changes were especially evident in older subjects with metastases.