Background: It is known that some elements are needed for normal thyroid gland functions. Iodine and selenium are the most well-known trace elements necessary for thyroid metabolism. Selenium is involved in the formation of thyroid hormones and the structure of the deiodinases associated with the development of the thyroid gland. While the role of zinc in thyroid metabolism is at the T3 receptor level, the role of copper is yet not clear. Objective: To compare the levels of serum trace elements such as selenium, zinc, and copper between the patients with euthyroid nodular goiter and healthy participants. Methods: This cross-sectional study included 98 patients with euthyroid multinodular goiter and 83 healthy subjects without thyroid disease. The demographics, thyroid hormone levels, and thyroid ultrasonography of the participants were recorded. Venous blood samples were centrifuged and sera samples were stored at -80°C until analysis of selenium, zinc, and copper levels. The levels of trace elements were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results: While serum, zinc, and selenium levels were significantly higher in the control group than the nodular goiter group, the copper levels were similar in the two groups. Trace elements were not correlated with thyroid hormone levels and thyroid volumes. Patients in the nodular goiter group were analyzed according to their solitary and multiple nodule status. The solitary and multiple nodular goiter groups were similar in terms of copper, zinc, and selenium levels. Conclusions: Deficiency of selenium and zinc may be associated with nodular goiter. Replacement of these trace elements may be useful for the prevention of nodular goiter, especially in deficient regions.

Selenium and iodine are essential microelements for normal body functions. These two elements play important roles in thyroid metabolism. The potential relationship between thyroid diseases and mental disorders have been demonstrated. We aimed to investigate the relationship between selenium and iodine levels with anxiety and depression in patients with euthyroid nodular goiter (ENG). In this cross-sectional study, we enrolled 102 consecutive patients with ENG who attended the endocrine outpatient clinic between January 2018 and June 2018. We noted the patient’s demographics, thyroid ultrasound imaging, thyroid hormones, and urinary iodine concentration (UIC) results. We also obtained venous blood samples for serum selenium measurement. The same psychiatrist completed the Beck Anxiety Inventory (BAI) and Hamilton Depression Rating Scale (HDRS) for all participants. The study population was dichotomized according to the median values of selenium levels and UIC. BAI and HDRS scores were significantly higher in the low selenium group than the high selenium group (p = 0.032 and p = 0.042, respectively). BAI scores were significantly higher in the low UIC group than the high UIC group (p = 0.007). Low selenium and UIC levels may contribute to the development of anxiety and depression, independent of thyroid functions, in patients with ENG. In these patients, selenium and iodine replacement may be useful for the prevention of anxiety and depression, especially in deficient regions.

Background/aim: The possibility of adverse effects of the oral glucose tolerance test (OGTF) carried out for the screening of gestational diabetes among pregnant women and fetuses is a frequently discussed topic. The purpose of this study was to investigate the effects of the hyperglycemia peak during OGTT on the levels of oxidants and antioxidants in the body. Materials and methods: Eighty individuals who applied to the Outpatient Clinic with suspected diabetes and OGTT indication were included in the study. Glucose, total oxidant capacity status (TOS), total antioxidant capacity (TAS), superoxide dismutase (SOD), and lipid hydroperoxide (LOOH) levels were tested on blood samples collected from these individuals at 0, 60, and 120 min during the OGTT carried out with 75 g of glucose. Oxidative stress index (OSI) was calculated as the ratio of TOS to TAS. Results: While the oxidative parameters TOS and LOOH were significantly increased at 60. min of OGTT, only LOOH was significantly increased at 120. min of OGTT. Significant decreases in antioxidative parameters (TAS, SOD) were observed at 60. and 120. min of the OGTT and OSI was significantly increased at 60. and 120. min of the OGTT. Conclusion: Oxidative stress parameters were increased and antioxidative parameters were decreased during the OGTT. However, more extended studies are required to determine the effects of the increased oxidative stress on pregnant women and fetuses.

Background: Thyroid hormone has been shown to control retinal cone opsin expression, the protein of color vision, in adult rodents. Objectives: The aim of this study was to evaluate the effect of hypothyroidism on color contrast sensitivity in adult overt hypothyroid patients. Methods: Thirty-eight overt hypothyroid (31 females, 7 males) subjects and 20 euthyroid (16 females, 4 males) controls were studied prospectively. Color vision examination was performed by Chromatest, a software program analyzing the tritan (blue-yellow) color contrast threshold (tritan CCT) and protan (red-green) color contrast threshold (protan CCT). Color contrast sensitivity analyses of hypothyroid subjects were performed on admission and after L-thyroxine treatment when biochemical euthyroidism was achieved. Results: After a median period of 90 (90-210) days, 24 (19 females, 5 males) patients were euthyroid and eligible for a second color vision examination. Baseline tritan CCT and protan CCT values were significantly higher in the hypothyroid group compared to euthyroid controls, which clinically translates into impaired color contrast sensitivity (p < 0.001 and p < 0.001, respectively). There was a significant decrease in tritan CCT (p = 0.002) and protan CCT (p < 0.001) values in the hypothyroid group after euthyroidism was achieved, which denotes improvement in color contrast sensitivity. Conclusions: It is a novel finding of the current study that color contrast sensitivity is impaired in hypothyroidism and significantly improves after euthyroidism is achieved.

Purpose. Previous studies have demonstrated the relationship between hyperthyroidism and increased risk of cardiac arrhythmias. The most common causes of hyperthyroidism are Graves' disease (GD) and toxic nodular goiter (TNG). The aim of our study was to demonstrate if the underlying mechanism of hyperthyroidism, in other words autoimmunity, has an impact on the type of cardiac arrhythmias accompanying hyperthyroidism. Method. Twenty patients with TNG and 16 patients with GD who had overt hyperthyroidism were included in the study. Age, sex, thyroid hormone levels, thyroid autoantibody positivity, thyroid ultrasonography and scintigraphy results were recorded. 24-hour Holter ECG monitoring was performed in all patients. Results. Mean age was significantly higher in the TNG group compared to the GD group (62.9 +/- 11.5 vs. 48.9 +/- 8.6 years, p=0.001). Free T3 was significantly higher (7.87 +/- 3.90 vs. 5.21 +/- 1.53 pg/mL, p=0.033) in the GD group while free T4 and TSH levels were similar between the two groups. In 24-hour Holter ECG recordings nonsustained ventricular tachycardia (VT) rates were significantly higher in the GD group than in TNG group [18.75% (n=3/16) vs. 0% (n=0/20), respectively, (p=0.043)] Paroxysmal atrial fibrillation (AF) rates were significantly higher in the TNG group compared to GD group [(30% (n=6/20) vs. 0% (n=0/16), respectively, (p=0.016)]. Conclusion. Although free T3 levels were lower, paroxysmal AF rates were found significantly higher in the TNG group which may be associated with significantly higher age of this group. On the other hand, higher rate of nonsustained VT in the GD group may be related to either significantly higher free T3 levels or autoimmunity.