IODINE STATUS AND THYROID FUNCTION IN LACTATING WOMEN AND INFANTS - A SURVEY IN THE ZAGREB AREA, CROATIA.

Lactating women (LW) and infants have high dietary iodine requirements and are at risk of iodine deficiency. The aim of the study was to assess iodine status and thyroid function in LW and their breastfed infants in Zagreb, Croatia. The study included 133 LW and breastfed infant pairs. Urinary iodine concentration (UIC) and thyroid function parameters were measured in all subjects. In LW, breast milk iodine concentration (BMIC) was measured and iodine and salt rich food frequency questionnaire data were collected. Results of analysis indicated that 99.2% of the LW used iodized salt in household and 20.4% used iodine-containing vitamin and mineral supplements. Median (IQR) UIC was 75 µg/L (19.0-180.5 µg/L) in LW and 234 µg/L (151.0-367.5 µg/L) in infants, whereas BMIC was 121 µg/kg (87.8-170.8 µg/kg). Multivariate regression analysis revealed BMIC to be a significant predictor of infant UIC (p<0.001). Positive correlation was recorded between LW and infant thyroid function. This was the first study in Croatia demonstrating BMIC to be a reliable biomarker of iodine status during lactation and predicting iodine intake in breastfed infants. The study confirmed that mandatory salt iodization in Croatia ensured sufficient dietary iodine for LW and optimal iodine intake for breastfed infants via breast milk.

Standardized Map of Iodine Status in Europe.

Background: Knowledge about the population's iodine status is important, because it allows adjustment of iodine supply and prevention of iodine deficiency. The validity and comparability of iodine-related population studies can be improved by standardization, which was one of the goals of the EUthyroid project. The aim of this study was to establish the first standardized map of iodine status in Europe by using standardized urinary iodine concentration (UIC) data. Materials and Methods: We established a gold-standard laboratory in Helsinki measuring UIC by inductively coupled plasma mass spectrometry. A total of 40 studies from 23 European countries provided 75 urine samples covering the whole range of concentrations. Conversion formulas for UIC derived from the gold-standard values were established by linear regression models and were used to postharmonize the studies by standardizing the UIC data of the individual studies. Results: In comparison with the EUthyroid gold-standard, mean UIC measurements were higher in 11 laboratories and lower in 10 laboratories. The mean differences ranged from -36.6% to 49.5%. Of the 40 postharmonized studies providing data for the standardization, 16 were conducted in schoolchildren, 13 in adults, and 11 in pregnant women. Median standardized UIC was <100 µg/L in 1 out of 16 (6.3%) studies in schoolchildren, while in adults 7 out of 13 (53.8%) studies had a median standardized UIC <100 µg/L. Seven out of 11 (63.6%) studies in pregnant women revealed a median UIC <150 µg/L. Conclusions: We demonstrate that iodine deficiency is still present in Europe, using standardized data from a large number of studies. Adults and pregnant women, particularly, are at risk for iodine deficiency, which calls for action. For instance, a more uniform European legislation on iodine fortification is warranted to ensure that noniodized salt is replaced by iodized salt more often. In addition, further efforts should be put on harmonizing iodine-related studies and iodine measurements to improve the validity and comparability of results.

Prediction of radioactive iodine remnant ablation failure in patients with differentiated thyroid cancer: A cohort study of 740 patients.

BACKGROUND: The purpose of this study was to detect parameters that could serve as predictors of radioactive iodine (I-131) ablation failure in patients with low-risk and intermediate-risk differentiated thyroid carcinoma (DTC). METHODS: Our cohort study included 740 patients with DTC who received postoperative I-131 remnant ablation. Anthropometric, biochemical, and pathohistological parameters were analyzed and correlated with ablation outcome using multivariable logistic regression models. RESULTS: Treatment failure rates were higher in patients <53 years, with N1a classification, and lymph node capsular invasion. In patients with N1a disease, thyroglobulin (Tg) > 2.4 ng/mL predicted treatment failure with 93.8% sensitivity and 52.5% specificity, and in patients with N1b disease, Tg > 14.9 ng/mL with 77.8% sensitivity and 92.9% specificity. I-131 activity was not associated with treatment outcome. CONCLUSION: Patients < 53 years old, with higher Tg levels, N1a classification, and lymph node capsular invasion have a higher risk of ablation failure. Stimulated Tg is an excellent predictor of treatment failure in patients with N1 disease. © 2016 Wiley Periodicals, Inc. Head Neck 39: 109-115, 2017.

Use of Alternative and Complementary Medicine in Patients with Malignant Diseases in High-Volume Cancer Center and Future Aspects

Usage of complementary and alternative medicine (CAM) is steadily increasing over the last decades, gaining medical, economic and sociological importance. The aim of the present study was to assess the use of complementary and alternative therapies in cancer patients. A cross-sectional, descriptive survey design was used to collect data through an anonymous questionnaire. A total of 267 patients were included in the study. The prevalence of CAM use among cancer patients in this study was 60.3%. It was found that 61 heterogeneous CAM therapies were used, the most popular among patients being naturopathy/folk medicine. In multivariate logistic regression analysis, independent predictors of CAM use were high income, divorced status, female sex and younger age. In conclusion, considering the fact that a large proportion of patients used at least one CAM approach, we need to continue our efforts to improve the patient-oncologist communication in order to deliver most reliable information to patients and to better understand the possible standard medicine-CAM interactions. According to results of the latest studies, CAM therapies that help manage pain, nausea, fatigue, anxiety, and other symptoms should be integrated into the patient overall care.

Adjuvant thyroid remnant ablation in patients with differentiated thyroid carcinoma confined to the thyroid: a comparison of ablation success with different activities of radioiodine (I-131).

OBJECTIVE: To assess efficiency of various I-131 activities on thyroid remnant ablation in thyroid cancer patients. The significance of patients' characteristics, pathologic features and levels of Tg were analyzed. PATIENTS AND METHODS: This study included 259 consecutive differentiated thyroid cancer patients, with disease confined to the thyroid, treated with I-131 after total thyroidectomy. Patients were divided into the three groups: 80 patients receiving low [1110-1850 MBq (30-50 mCi)], 121 intermediate [2775 MBq (75 mCi)] and 58 high [3700 MBq (100 mCi)] postoperative I-131 activities. Six to eight months after the application of radioiodine, measurements of TSH, Tg, anti-Tg antibodies (in hypothyroid state) together with ultrasound exam and whole-body scintigraphy were performed. RESULTS: The ablation was significantly more effective (after the first application) in patients receiving 100 mCi of I-131-89.7% than in patients receiving lower activities (P = 0.016). There was no significant difference in ablation rate between the 30-50 mCi (77.5%) and 75 mCi (70.2%) groups. In the group receiving 30-50 mCi, patients with solitary tumors had significantly higher ablation rate (P = 0.038). In patients receiving 75 mCi ablation rates were higher among older patients (P = 0.005), with infiltration of the single lobe (P = 0.005), and with solitary tumor (P = 0.012). The rates of successful ablation after the second application of I-131 (after 12-16 months) amounted to 96, 97 and 96% in the 30-50, 75 and 100 mCi groups, respectively. The activity of I-131 and age were independent factors for thyroid ablation failure after the first application of I-131 (model of binary logistic regression). CONCLUSION: The results of remnant ablation were satisfactory with all activities applied. Although after the first application of I-131 the activity of 100 mCi is significantly more effective in thyroid ablation than the administration of 30-50 mCi and 75 mCi, the ablation rates between all the three groups are similar (almost equal) after the second application. Thus, the activity to be administered may depend on patients' characteristics and a detailed consideration of the merits and demerits of each I-131 activity.

Postoperative use of radioiodine (131-I): review of recommendations and guidelines.

In the management of large number of patients with differentiated thyroid cancer, the radioactive iodine (131-I) administration plays an important role. The guidelines of numerous international and national medical societies regarding the issue of postoperative 131-I administration have been published and updated in the last few years. The guidelines differ in the shape and content, and contain some specific features. The different methods for evaluation and analysis of clinical evidence level and resulting grades of recommendations have been used in line with the very guidelines. The postoperative 131-I administration refers to the radioiodine ablation as a form of adjuvant treatment and radioiodine therapy in the management of patients with recurrent cancer, persistent disease and regional or distant metastases. According to the indications for the postoperative 131-I administration, the patients could be divided into the three risk groups: the very low risk group in which there is no indication for the postoperative 131-I administration, the low risk group in which the indication could be considered, and the high risk group in which there is a clear indication for the 131-I administration. The different criteria for distribution of patients into these three groups are expressed in a certain guidelines. There are different opinions about the necessary dosage of 131-I for the efficient ablation in the low risk group. Moreover, the opinions are also divided regarding the conduction of postoperative (preablative or pretherapeutic) scintigraphy with 131-I. As regards the instructions on preparation of patients for the radioiodine ablation and therapy, all the guidelines recommend the low iodine diet and endogenous or exogenous stimulation of TSH. The endogenous stimulation is accomplished by the withdrawal of thyroid hormones, whereas the recombinant human TSH (rhTSH) is used for exogenous stimulation. For conducting the therapy with 131-I the level of TSH has to be > 25-30 mU/L.

Iodine supplementation in pregnancy.

People of all ages can be affected by iodine deficiency, however, pregnant women and children are especially at a high risk. Because of changes that occur in maternal thyroid hormone economy during pregnancy and the potential unfavorable effects of iodine deficiency on the offspring, an adequate dietary iodine intake throughout the pregnancy is highly important. Therefore, the World Health Organization, United Nations Children's Fund and International Council for the Control of Iodine Deficiency Disorders have proposed that dietary intake of iodine during pregnancy should be 200-300 microg/day to compensate for the augmented T4 requirements in pregnant women. It has been shown that in countries with a longstanding and well-established universal salt iodination program where iodine sufficiency has been reached, there is a fraction of pregnant women that still have low median urinary iodine concentration, which indicates insufficient dietary iodine. Studies performed in such countries emphasize that pregnant women should use multivitamin and/ or mineral tablets specifically prepared for the needs of pregnancy and containing iodine supplements. Only the United States of America and Canada have official recommendations concerning iodine supplementation. In other countries, no such firm decisions have yet been made by medical community and public health authorities. In Croatia, an iodine sufficient country, the situation is the same. There is a need to collect adequate data on iodine supplementation and urinary iodine during pregnancy, along with the universal salt iodination program, so that definitive conclusions can be made.

The effect of antioxidant supplementation on superoxide dismutase activity, Cu and Zn levels, and total antioxidant status in erythrocytes of patients with Graves' disease.

The effects of supplementation with a fixed combination of antioxidants (vitamins C and E, beta-carotene and selenium) on superoxide dismutase activity, copper and zinc concentrations, and total antioxidant status were monitored in erythrocytes derived from a group of patients with Graves' disease treated with methimazole, with respect to the rate of achieving euthyroidism. Thyroid-stimulating hormone (TSH), thyroid hormones and the above-mentioned parameters were measured before therapy, and on days 30 and 60 after therapy initiation. The patients receiving antioxidant supplementation along with methimazole therapy (group A, n = 27) achieved euthyroidism at a faster rate than those treated with methimazole alone (group B, n = 28). The activity of superoxide dismutase decreased significantly in both patient groups during the treatment; however, there was no significant difference between the groups. There was no significant change in the erythrocyte concentration of copper, whereas the zinc concentration and total antioxidant status showed significant between-group differences. The study results clearly show that antioxidant supplementation in the treatment of Graves' disease is justified, while zinc and total antioxidant status in erythrocytes seem to be sensitive indicators of the efficacy of supplemental therapy.