Trace elements status in multinodular goiter

Importance of iodine and selenium in thyroid metabolism is well known, but the roles of other essential trace elements including copper, zinc, manganese and iron on thyroid hormone homeostasis remain unclear. The aim of this study was to investigate the status of those trace elements in benign thyroid diseases and evaluate possible links between trace element concentrations and thyroid hormones.The study group was composed of 25 patients with multinodular goiter. Concentrations of thyroid hormones (plasma-free thyroxine, FT₄; free triiodothyronine, FT₃; and thyrotropin, TSH), selenium, copper, zinc, manganese and iron in plasma, and urinary iodine were determined. The results were compared with those of a healthy control group (n=20) with no thyroid disorder.A mild iodine deficiency was observed in the patients with multinodular goiter whereas urinary iodine levels were in the range of “normal” values in healthy controls. All patients were euthyroid, and their thyroid hormone concentrations were not significantly different from the control group. Plasma selenium, zinc and iron concentrations did not differ from controls, while copper and manganese levels were found to be significantly higher in the patients with multinodular goiter indicating links between these trace elements and thyroid function and possibly in development of goiter. Besides iodine, there was a significant correlation between plasma copper concentration and FT₃/FT₄ ratio.     

Exploring the role of copper and selenium in the maintenance of normal thyroid function among healthy Koreans

BackgroundSelenium and iodine are trace elements well known to have important roles in the synthesis and metabolism of thyroid hormones. However, the effects of other trace elements on thyroid hormones are still inconclusive. We investigated the association between several trace elements and thyroid hormones.MethodsThe data of 448 subjects who were measured for both, trace elements and TSH/free T4, at the Heath Checkup Center were retrospectively reviewed. The presence of thyroiditis (from thyroid echogenicity) and thyroid nodules were reviewed in the subjects who underwent thyroid ultrasonography.ResultsBlood concentrations of manganese, copper, selenium, and molybdenum were associated with TSH or free T4. After adjusting for age, sex, BMI, smoking, and alcohol consumption, blood copper levels were positively associated with free T4 in both sexes and selenium levels were positively associated with free T4 in women. There was no association between trace elements and thyroiditis. Blood copper concentration had a weak non-linear association with the presence of thyroid nodules.ConclusionsThis study demonstrated that blood concentrations of copper and selenium were significantly associated with free T4 in healthy Korean subjects with sufficient iodine intake suggesting their role in maintaining normal thyroid function.     

Selenium, iron, copper, and zinc levels and copper-to-zinc ratios in serum of patients at different stages of viral hepatic diseases

Viral hepatic diseases, especially those induced by the hepatitis B virus, can progress into more serious pathological outcomes and eventually to hepatocellular carcinoma. A growing body of evidence indicates that many trace elements play important roles in a number of carcinogenic processes that proceed through various mechanisms. To examine the status of trace elements during the development of hepatic carcinoma, we determined the selenium, iron, copper, and zinc levels and copper-to-zinc ratios in the serum of patients at different stages of viral hepatic disease. We observed significant changes in the selenium, iron copper, and zinc levels in the serum of patients having hepatocellular carcinoma, relative to those of healthy controls (p<0.05). The mean serum copper level in patients with hepatocellular carcinoma was significantly higher than that of the control group. In contrast, the mean selenium, iron, and zinc levels in patients having hepatocellular carcinoma were significantly lower than those of the control group. In addition, the mean zinc level in the serum of patients with hepatic cirrhosis was significantly lower than that of the control group (p<0.05). Moreover, we found markedly elevated Cu: Zn ratios (p<0.05) in patients having hepatic cirrhosis or hepatocellular carcinoma. Our findings imply that the levels of some trace elements, such as selenium, iron, copper, and zinc, and Cu:Zn ratios, might serve as biomarkers for the increased severity of viral hepatic damage.     

Significance of serum trace element status in patients with rheumatic heart disease

It is known that certain trace elements can affect various heart diseases. In this study, we aimed to evaluate the changes in concentrations of certain serum trace elements in patients with chronic rheumatic heart disease (RHD). Serum analysis of selenium (Se), zinc (Zn), and copper (Cu) trace elements was assayed by atomic absorption spectrophotometry. RHD patients had significantly lower serum concentrations of Se and Zn than control subjects (p<0.05 and p<0.001, respectively). However, the serum Cu concentration was significantly higher in RHD patients than in controls (1.93±0.59 μg/L vs 1.06±0.29 μg/L; p<0.001). Similarly, the Cu/Zn ratio in RHD patients was higher than in control subjects (4.70±0.92 vs 1.68±0.45; p<0.001). Additionally, no significant correlation was found among these trace element concentrations and the functional capacity classes (p>0.05). RHD patients had decreased serum Se and Zn element concentrations and increased serum Cu element concentration. We suggest that Se and Zn deficiency might be contributory factors in the development of rheumatic heart disease, and a high Cu concentration and a high Cu/Zn ratio might reflect an ongoing inflammatory process in this disease.     

Association between concentration of trace elements in serum and bronchial asthma among Japanese general population

Background and aimsA number of previous studies had revealed the association between trace elements in serum and bronchial asthma. However, only a few researches had focused on serum concentration of trace elements in a general population. In this study, an association between trace elements in serum and bronchial asthma was investigated in a general population.MethodsSubjects were 1025 volunteers (385 males and 640 females between ages 19 and 82 years old) who had participated in the Iwaki Health Promotion Project 2005. Bronchial asthma was diagnosed based on the European Community Respiratory Health Survey II according to the self-questionnaires on health conditions of subjects. The serum concentrations of certain trace elements (manganese, copper, zinc, selenium and iron) were measured and compared. Also, an association between serum trace elements level and neutrophil-related functions (oxidative burst activity, phagocytic activity, serum opsonic activity) were determined.ResultsIn males, no significant differences were seen in any serum trace elements concentrations. In females, serum zinc level was significantly higher in bronchial asthma group than in control. A positive correlation was seen between serum concentration of zinc and serum opsonic activity in both genders.ConclusionsIn female asthmatics, increase of oxidative stress was suggested to be caused by superoxide dismutase pathway (elimination system of reactive oxygen species) rather than serum opsonic activity (production system of reactive oxygen species from neutrophils) pathway, as the zinc concentration in bronchial asthma group was higher than that in control.     

Increased oxidative stress and altered serum macro-minerals and trace elements levels are associated with coronary artery disease

BackgroundThis study was designed to evaluate the serum malondialdehyde (MDA), non-enzymatic antioxidants (vitamin A and C), macro-minerals (magnesium and calcium), and trace elements (zinc, copper, and iron) levels in patients with coronary artery disease (CAD) and to explore their role in disease progression.MethodsThis prospective case-control study was comprised of 40 CAD patients and 40 healthy volunteers as cases and control subjects, respectively. The level of lipid peroxidation was assessed by measuring the serum MDA level using a UV spectrophotometer. The levels of vitamins A and C were determined by high-performance liquid chromatography (HPLC) and UV spectrophotometric method, respectively. Atomic absorption spectroscopy (AAS) was used to measure serum macro-minerals (Mg and Ca) and trace elements (Zn, Cu, and Fe) concentrations.ResultsThe mean age of CAD patients and control subjects was 53.90 ± 2.22 and 37.03 ± 1.50 years, respectively. This study revealed significantly higher concentrations of MDA (p < 0.01) and lower concentrations of vitamin A (p < 0.01), and vitamin C (p < 0.05) in the CAD patients than in control subjects. The mean values of Mg, Cu, Zn, Ca, and Fe were 11.67 ± 0.64, 1.17 ± 0.03, 0.43 ± 0.02, 107.38 ± 1.81, and 1.66 ± 0.04 μg/mL, respectively for the CAD patients and 19.38 ± 0.65, 1.07 ± 0.02, 0.87 ± 0.02, 94.29 ± 1.89, and 1.52 ± 0.05 μg/mL, respectively for the controls and the differences were significant (p < 0.05) between the patients and controls.ConclusionFrom these findings, we can suggest that there is a strong association of CAD with an elevated level of MDA, depleted levels of antioxidants, and altered macro-minerals and trace elements concentrations.     

Trace element levels in serum and gastric mucosa in patients with Helicobacter pylori positive and negative gastritis

BackgroundMost trace elements are inhibited by Helicobacter pylori-infection, and variations in specific element levels are linked to the development of stomach cancer. This is the first study to show the relationship between serum and tissue concentrations of twenty-five trace elements and H. pylori infection status. This study purposed to define serum and tissue trace element levels of 25 healthy individuals with Helicobacter pylori-positive gastritis and Helicobacter pylori-negative gastritis and to reveal their relationship with the disease.MethodsStudy groups consisted of sixty-two patients with Helicobacter pylori-positive, thirty-seven patients with Helicobacter pylori-negative, and thirty healthy individuals. Serum and tissue concentrations of twenty-five elements (aluminum, boron, arsenic, barium, calcium, beryllium, copper, cadmium, iron, chromium, mercury, lithium, potassium, magnesium, sodium, manganese, nickel, phosphorus, lead, scandium, strontium, selenium, tellurium, titanium, zinc) were defined by inductively coupled plasma optical emission spectrometry.ResultsExcept for copper, lithium, and strontium elements in serum samples, other trace elements differed significantly between the groups (p < 0.05). The serum chromium (p = 0.002), mercury (p = 0.001), boron (p < 0.001), and cadmium (p < 0.001) levels of H. pylori-negative gastritis and H. pylori-positive gastritis participants were significantly different, and their serum concentrations were less than 0.5 µ/l. Boron, barium, beryllium, chromium, lithium, phosphorus and strontium elements in tissue samples did not differ significantly between the groups (p > 0.05). Manganese, nickel, tellurium and titanium elements were not detected in tissue and serum samples. The mean concentrations of calcium, beryllium, chromium, iron, potassium, lithium, magnesium, scandium, and selenium were higher in the tissues of patients with H. pylori gastritis compared to healthy control tissues. Also, cadmium could not be detected in tissue samples. There was a significant difference between H. pylori-infected tissue and serum chromium levels (p = 0.001), with lower levels detected in tissue samples.ConclusionThis is the first study that we are knowledgeable of that reports the concentrations of twenty five elements in both serum and tissue samples, as well as the relationship between trace elements and Helicobacter pylori-infection status. Dietary adjustment is indicated as an adjunct to medical therapy to stabilize trace elements because Helicobacter pylori bacteria cause inflammation and impair element absorption in gastritis patients. We also think that this study will shed light on studies on the relationship between Helicobacter pylori-trace elements and serum-tissue/healthy serum-tissue trace element levels of patients with Helicobacter pylori gastritis.     

Levels of selenium, zinc, copper, and antioxidant enzyme activity in patients with leukemia

Essential elements, mainly selenium and zinc, were involved in protection against oxidative stress in cells. Oxidation could lead to the formation of free radicals that have been implicated in the pathogenesis of many diseases, including leukemia. Leukemia is a neoplastic disease that is susceptible to antioxidant enzyme and essential elements alterations. This study was undertaken to examine the levels of essential elements, antioxidant enzymes activities, and their relationships with different types of leukemia. Serum selenium, zinc, and copper concentrations, red blood cell glutathione peroxidase (GPx) activities, plasma Cu−Zn superoxide dismutase (Cu−Zn SOD) activities and lipid peroxidation (LPO) levels were determined in 49 patients with different types of leukemia before initial treatment. Serum selenium and zinc concentrations were lower in leukemia patients than those of controls (p<0.01). Serum copper concentration was higher in leukemia patients than that of controls (p<0.01). The activities GPx and Cu−Zn SOD were significantly increased in leukemia patients, especially with acute leukemia (AL), acute lymphoid leukemia (ALL), and acute nonlymphoid leukemia (ANLL) (p<0.05), whereas no difference was found between those of chronic myelogeneous leukemia and the controls. The levels of LPO were normal as controls. Serum selenium concentration was not correlated with GPx, and serum levels of zinc and copper were not related to Cu−Zn SOD. Serum zinc levels had a negative correlation with the absolute peripheral blast cells, whereas serum copper had a positive correlation with the absolute peripheral blast cells. Increased GPx and Cu−Zn SOD activities and normal levels of LPO, which were a protective responses, were an indicator of mild oxidative stress; it mights indicate that the essentials elements alterations in leukemia patients were mostly dependent on tumor activity. Changes of their levels demonstrated that there are low selenium, zinc, and high copper status in leukemia patients. The decrease of plasma zinc and increase of the Cu/Zn ratio could be the index that showed an unfavorable prognosis of acute leukemia.     

Zinc, Copper, and Selenium Tissue Levels and Their Relation to Subcutaneous Abscess, Minor Surgery, and Wound Healing in Humans

Trace element involvement in wounds left to heal by secondary intention needs clarification. We have previously reported faster healing of wounds following acute surgery compared with elective excision of pilonidal sinus disease. The effect of topical zinc on the closure of the excisional wounds was mediocre compared with placebo. In contrast, parenteral zinc, copper, and selenium combined appear effective for wound healing in humans. We have investigated zinc, copper, and selenium with respect to (a) impact of acute versus chronic pilonidal sinus and (b) regional concentrations within granulating wounds treated topically with placebo or zinc in 42 (33 males) pilonidal disease patients. Baseline serum and skin concentrations of copper correlated (r _S?=?0.351, p?=?0.033, n?=?37), but not of zinc or selenium. Patients with abscesses had elevated serum C-reactive protein (CRP) and copper levels (+29 %; p?<?0.001) compared with the elective patients consistent with the strong correlation between serum copper and CRP (r _S?=?0.715, p?<?0.0005, n?=?41). Seven days after elective surgery, serum CRP and copper levels were elevated (p?=?0.010) versus preoperative values. The copper concentration in wound edges was higher than in periwound skin (p?<?0.0005) and wound base (p?=?0.010). Selenium levels were increased in wound edge compared to wound base (p?=?0.003). Topical zinc oxide treatment doubled (p?<?0.050) zinc concentrations in the three tissue localizations without concomitant significant changes of copper or selenium levels. In conclusion, copper and selenium are mobilized to injured sites possibly to enhance host defense and early wound healing mechanisms that are complementary to the necessity of zinc for matrix metalloproteinase activity.     

Evaluation of homocysteine,vitamin, and trace element levels in women with gallstones

ObjectiveIt was aimed to examine the changes in homocysteine, folic acid, and vitamin B12, which metabolize homocysteine from the body, and trace elements (zinc, copper, selenium, nickel) that affect the structure of tissues and epithelium in female patients with gallstone disease. Moreover, it was aimed to investigate the contribution of these selected parameters to the etiology of the disease and their usability in treatment according to the findings obtained.Materials and MethodsEighty patients, including 40 female patients (Group I) and 40 completely healthy female individuals (Group II) were included in this study. Serum homocysteine, vitamin B12, folate, zinc, copper, selenium, and nickel levels were evaluated. Electrochemiluminescence immunoassay was used in the analysis of vitamin B12, folic acid, and homocysteine levels, and the ICP-MS method was used in the analysis of trace element levels.ResultsHomocysteine levels in Group I were statistically significantly higher than in Group II. In terms of vitamin B12, zinc, and selenium, Group I levels were found to be statistically significantly lower than group II. There was no statistically significant difference between Group I levels and Group II in terms of copper, nickel, and folate.ConclusionIt was suggested that homocysteine, vitamin B12, zinc, and selenium levels should be determined in patients with gallstone disease and that vitamin B12, which is especially important in the excretion of homocysteine from the body, and zinc and selenium, which prevent the free radical formation and protect from its effects, should be added to the diets of these patients.     

BMI and levels of zinc,copper in hair,serum and urine of Turkish male patients with androgenetic alopecia

ObjectiveMale pattern androgenetic alopecia is characterized by progressive hair loss from the scalp. It is known that imbalances of some trace elements play a role in the pathomechanism of many forms of alopecia. The aim of this study was to evaluate the levels of zinc and copper in hair, serum and urine samples of Turkish males with male pattern androgenetic alopecia and to compare with healthy controls.Material and methods116 males with male pattern androgenetic alopecia and 100 controls were involved in this study.ResultsLevels of zinc and copper in hair were decreased significantly in the patients (p < 0.05), although zinc and copper levels of serum and urine were not different between patients and controls (p > 0.05). Body mass index of patients were higher than control group. In addition, in the group with body mass index of 25 and lower zinc level in hair and urine, copper level in serum were significantly higher (p < 0.05). Body mass index was negatively correlated with hair zinc levels.ConclusionWe thought that decreased zinc and copper levels in hair may play a role in the etiology of male pattern androgenetic alopecia. In addition, obesity by making changes in the balance of the trace elements in hair, serum and urine may play a role in male pattern androgenetic alopecia. Hence, assessing the levels of trace elements in hair of male pattern androgenetic alopecia patients may be more valuable compared to serum and urine for treatment planning.     

Altered Plasma Concentrations of Trace Elements in Ulcerative Colitis Patients Before and After Surgery

Ileal pouch-anal anastomosis (IPAA) is a classical surgery for ulcerative colitis patients. However, knowledge on trace element alteration in patients who had undergone this surgery is limited. This study was conducted to assess trace element alteration in patients with ulcerative colitis before and after ileal pouch-anal anastomosis. Preoperative (40) and postoperative (35) ulcerative colitis patients were studied. The dietary assessment of trace element intake was undertaken by a semiquantitative food frequency questionnaire. Patients' trace element status of zinc, copper, manganese, selenium, calcium, iron, and vitamin D₃ was assessed by measuring their blood concentrations. We found that with the similar dietary intake, there was no statistical difference in the concentrations of plasma copper, iron, calcium, and vitamin D₃ in the two groups (P?>?0.05). Compared with preoperative patients, postoperative patients had higher concentrations of plasma zinc (14.51?±?4.75 μmol/l) and manganese (0.21?±?0.11 μmol/l) and lower concentrations of plasma selenium (0.86?±?0.58 μmol/l). Both preoperative and postoperative mean concentrations of plasma calcium and vitamin D₃ were below their reference range, respectively. We conclude that IPAA does not seem to alter patients' abnormal trace elements completely. It is important to monitor and supply some specified trace elements even in postoperative patients.     

Selenium and zinc in patients with acute and chronic uveitis

Patients with chronic inflammation often show decreased serum levels of trace elements. This study aimed to investigate serum levels of selenium and zinc in patients with uveitis. Twenty-four patients (13 female, 11 male) with a mean age of 40.6±15.5 yr were included in this study. According to their underlying disease, they were divided into acute (n=13) or chronic (n=11) uveitis. Selenium and zinc determination was performed by atomic absorption spectroscopy in EDTA blood samples. Patients with acute or first-time uveitis showed selenium and zinc concentrations within the normal range. In contrast to this, patients with chronic recurrent uveitis tend to result in decreased selenium and zinc levels. Especially selenium showed a remarkable reduction in serum concentration below the normal range. Furthermore, there was a tendency to decreased trace element concentrations with increasing age. A sex dependency could not been found. Especially patients with chronic, recurring uveitis show remarkable decreased selenium concentration in the EDTA-blood. Further studies should investigate possible positive effects of therapeutic selenium and zinc supplementation in patients with chronic, recurrent uveitis.     

Significance of serum trace element status in patients with rheumatic heart disease: a prospective study

It is known that certain trace elements can affect various heart diseases. In this study, we aimed to evaluate the changes in concentrations of certain serum trace elements in patients with chronic rheumatic heart disease (RHD). Serum analysis of selenium (Se), zinc (Zn), and copper (Cu) trace elements was assayed by atomic absorption spectrophotometry. RHD patients had significantly lower serum concentrations of Se and Zn than control subjects (p < 0.05 and p < 0.001, respectively). However, the serum Cu concentration was significantly higher in RHD patients than in controls (1.93 +/- 0.59 microg/L vs 1.06 +/- 0.29 microg/L; p < 0.001). Similarly, the Cu/Zn ratio in RHD patients was higher than in control subjects (4.70 +/- 0.92 vs 1.68 +/- 0.45; p < 0.001). Additionally, no significant correlation was found among these trace element concentrations and the functional capacity classes (p > 0.05). RHD patients had decreased serum Se and Zn element concentrations and increased serum Cu element concentration. We suggest that Se and Zn deficiency might be contributory factors in the development of rheumatic heart disease, and a high Cu concentration and a high Cu/Zn ratio might reflect an ongoing inflammatory process in this disease.     

Concentations of copper, Zinc, and magnesium in sera from patients with idiopathic dilated cardiomyopathy

Trace elements are known to have a key role in myocardial metabolism. The accumulation (cobalt, arsenic, copper) or deficiency (selenium, zinc) of trace elements may be responsible for idiopathic dilated cardiomyopathy. We investigated the trace element concentrations (Cu, Zn, Mg) in sera from patients with dilated cardiomyopathy by atomic absorption spectrophotometry. We observed that patients with dilated cardiomyopathies have higher copper and lower zinc concentrations in serum than healthy controls. The magnesium concentrations of patients did not differ significantly from that of control subjects.     

Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients

The present study aims to examine the changes in the serum levels of trace elements before and after the operation in thyroid cancer patients. The study registered 50 individuals, of whom 25 were female and 25 were male. The patients were allocated to four groups: group 1: male thyroid cancer patients group (n = 15), group 2: female thyroid cancer patients group (n = 15), group 3: male control group (n = 10), group 4: female control group (n = 10). The subjects in groups 1 and 2 were the patients who were post-operatively diagnosed with a pathological malignancy in the thyroid tissue samples. Blood samples were collected from all subjects before the operation, immediately after the operation, and on the post-operative day 15. Additionally, thyroid tissue samples were taken from all subjects post-operatively. Some elements in the blood and tissue samples were determined using the atomic emission method. Zinc and selenium levels of groups 1 and 2 in the pre- and post-operative measurements were significantly lower than those in the control groups (p < 0.05), but were higher in the thyroid tissue (p < 0.05). Serum zinc and selenium levels measured in the subjects on the post-operative day 15 were similar to those measured in the controls. Our study show that changes in the serum and thyroid tissue levels of trace elements like zinc and selenium, which play a critical role in thyroid function, might be associated with the pathogenesis of thyroid cancer.     

Serum and hair levels of zinc, selenium, iron, and copper in children with iron-deficiency anemia

In the present study, the serum and hair levels of zinc, selenium, and copper were determined in children with iron-deficiency anemia (IDA). A total of 52 anemic children aged 1–4 yr constituted the study group. Fortysix healthy children acted as controls. The copper and zinc levels were measured with an atomic absorption spectrophometer. Serum and hair selenium was determined by a spectroflourometric method. The serum zinc and selenium concentrations in the IDA group were found to be significantly lower and serum copper significantly higher than those in the controls (p<0.05). Lower iron, zinc, and selenium concentrations (p<0.001) but not copper were found in hair (p>0.05).     

Intraluminal thrombus thickness is not related to lower concentrations of trace elements in the wall of infrarenal abdominal aortic aneurysms

BackgroundIntraluminal thrombus (ILT) formation plays a significant role in the progression of infrarenal abdominal aortic aneurysms (AAA). Potentially, as ILT thickness increases the availability of trace elements in the aneurysm wall could decrease thereby leading to oxidative stress and intensifying pro-inflammatory cytokine generation.AimTo determine if thrombus thickness is related to the concentration of trace elements in the wall of infrarenal AAA.Patients and methodsThe concentrations of trace elements in the wall of the aneurysm sack and ILT obtained from 19 consecutive patients during surgery for infrarenal AAA were determined using emission spectrometry.ResultsThe concentrations of magnesium, zinc, manganese, and lead in the wall of AAA were significantly greater than in the ILT. Only the concentration of copper was lower in the AAA wall compared with the thrombus. The concentration of calcium, phosphorus, zinc, lead, copper, and magnesium increased with ILT thickness. The concentrations of no other trace elements in the wall of AAA were found to be related to the ILT thickness.ConclusionsIntraluminal thrombus thickness is not associated with a lower concentration of trace elements in the wall of the infrarenal AAA. Thus, the intraluminal thrombus participates in the progression of AAA by mechanisms independent of trace element supply to the wall of the aneurysm sack.     

High serum concentration of selenium,but not calcium,cobalt, copper,iron, and magnesium,increased the risk of both hyperglycemia and dyslipidemia in adults: A health examination center based cross-sectional study

BackgroundMetabolic disorders of glucose and lipid were associated with some mineral elements, and data were warranted from various contexts to make the association more explicit.ObjectiveTo investigate the relationships between the serum concentrations of six mineral elements (calcium, cobalt, copper, iron, magnesium, and selenium) and the risk of hyperglycemia and dyslipidemia in adults.MethodsThe basic information and the over-night fasting serum samples of adults were randomly collected at a health examination center. The serum concentrations of glucose and lipids were measured with an automatic biochemical analyzer, and the mineral elements were measured with an inductively coupled plasma mass spectrometer. Data were analyzed between the hyperglycemia group (HGg) and the normal glucose group (NGg) as well as between the dyslipidemia group (DLg) and the normal lipid group (NLg).ResultsA total of 1466 adults aged 22–81 years (male/female = 1.8) were included, 110 in the HGg and 1356 in the NGg, or 873 in the DLg and 593 in the NLg. The serum element concentration medians [P50 (P25–P75)] significantly different between the HGg and the NGg were 0.83 (0.75–0.94) vs. 0.76 (0.68–0.87) mg/L for copper and 100 (90–110) vs. 94 (87–103) μg/L for selenium (P < 0.001), while those between the DLg and the NLg were 99 (92–110) vs. 97 (90–106) mg/L for calcium, 0.78 (0.69–0.88) vs. 0.75 (0.66–0.85) mg/L for copper, 1.7 (1.4–2.0) vs. 1.6 (1.3–2.0) mg/L for iron, 24 (22–28) vs. 23 (22–27) mg/L for magnesium, and 97 (89–106) vs. 92 (84–100) μg/L for selenium (P < 0.05). When the copper and selenium between the HGg and the NGg were analyzed by logistic regression with age, gender, body mass index, and mineral elements adjusted, only the highest quartile of selenium concentration had association with the increased risk of hyperglycemia [quartile (Q) 4 against Q1: OR = 2.9, 95 % CI = 1.5–5.5, P < 0.001). When the five differed mineral elements between the DLg and the NLg were similarly analyzed, only iron and selenium had associations with the increased risk of dyslipidemia (e.g., Q4 against Q1: OR = 1.4, 95 % CI = 1.1–2.0 for iron and OR = 2.9, 95 % CI = 2.1–4.0 for selenium, P < 0.05).ConclusionIn contrast to those of calcium, cobalt, copper, iron, and magnesium, the higher serum concentration of selenium increased the risk of both hyperglycemia and dyslipidemia in the study population of adult Chinese.     

The trace element selenium and the thyroid gland.

Apart from the essential trace element iodine, which is the central constituent of thyroid hormones, a second essential trace element, selenium, is required for appropriate thyroid hormone synthesis, activation and metabolism. The human thyroid gland has the highest selenium content per gram of tissue among all organs. Several selenocysteine-containing proteins respectively enzymes are functionally expressed in the thyroid, mainly in thyrocytes themselves: three forms of glutathione peroxidases (cGPx, pGPx, and PH-GPx), the type I 5-deiodinase, thioredoxin reductase and selenoprotein P. The thyroidal expression of type II 5-deiodinase still is controversial. As thyrocytes produce H2O2 continuously throughout life an effective cell defense system against H2O2 and reactive oxygen intermediates derived thereof is essential for maintenance of normal thyroid function and protection of the gland. In experimental animal models long-term and strong selenium deficiency leads to necrosis and fibrosis after high iodide loads. Combined iodide and selenium deficiency such as in central Zaire is thought to cause the myxedematous form of endemic cretinism. Inadequate selenium supply and prediagnostically low serum selenium levels are significantly correlated with the development of thyroid carcinoma and other tumors. Though selenium supply controls expression and translation of selenocysteine-containing proteins no direct correlation is found between selenium tissue content and expression of various thyroidal selenoproteins, indicating that other regulatory factors contribute to or override selenium-dependent expression control, e.g., in thyroid adenoma, carcinoma or autoimmune disease. As both trace elements, iodine and selenium, were washed out from the upper layers of the soil during and after the ice ages in many regions of the world adequate supply with these essential compounds needs to be provided either by a balanced diet or supplementation.