The Effect of Humic Acid Substances on the Thyroid Function and Structure in Lead Poisoning

Comparison of Thyroid Function in Lead-Poisoned Patients and Healthy Individuals in Eastern Iran

Lead (Pb) is a prevalent environmental toxic metal that may harmfully affect the function of the thyroid gland. Our information about the effects of lead on thyroid function in lead poisoning is limited. The present study aimed to evaluate thyroid function in lead-poisoned patients compared with the healthy group. In this study, two groups of lead poisoning subjects (lead concentrations ≥ 25 μg/dL) (n = 56) (HBLC group) and randomly selected age and gender-matched healthy individuals with lower blood lead concentrations (BLC < 10 μg/dL) (n = 58) (LBLC group) were included. Thyroid function tests, including thyroxine (T4), triiodothyronine (T3), and thyroid-stimulating hormone (TSH) concentration, were measured for each patient in both groups (for the HBLC group, it was taken on admission). The linear regression model was used to investigate the effects of lead poisoning on thyroid function tests. A p-value of less than 0.05 was considered significant. Our study showed no significant difference between the two groups in terms of age and gender. The mean concentration of T3 and TSH in the HBLC group was significantly lower than the LBLC group, but the mean levels of T4 were significantly higher in the HBLC group (p < 0.05). Based on the linear regression model results, the T3 and TSH levels in the LBLC group were significantly higher by 13.86 and 0.43 units than the HBLC group, respectively. The current study results showed that lead poisoning affects thyroid function, reduces TSH, and increases T4.

Impact of Dietary Humic Substances Supplementation on Selected Minerals in Muscles of Broiler Chickens

In this study, we assessed the effect of humic substances on the changes of some mineral (Ca, Mg, Cu and Zn) content in the thigh and breast muscle of broilers. Group 1 (G1) was supplemented with 0.7 % Humac Natur Mycosorb (HNMy), and G2 with 0.3 % HNMy. The control group (GC) received a basal diet without any supplements. In the breast muscle of broilers from the group G1 we found a statistically significantly higher (P < 0.05) Ca content and significantly reduced (P < 0.05) in the thigh muscle Ca content from the group G2 compared to the control group (GC). A statistically significant increase in Mg content (P < 0.05) was analyzed in breast muscles in the group G1 and also significant reduction (P ≤ 0.01) in Cu in the breast and thigh muscles was found in the group G1 and in the breast muscle from the group G2 compared to the GC. Significantly lower content of Zn (P ≤ 0.05) was found in the breast and thigh muscles of broilers in the group G2 and strong positive correlation (r = 0.9093) were observed between Ca in breast muscle from the group G2 and Ca in thigh muscle from the control group. A negative correlation (r = –0.7656) was shown for Mg between thigh muscle from the group G2 and Ca in thigh muscle from the GC. A strong negative correlation was confirmed (r = –0.9221) for Zn content in breast muscles between groups G2 and G1. The high positive correlation for Zn was occurred between breast muscle from the control group and thigh muscle from the group G1 (r = 0.9786).

Impact of humate substances and Bacillus subtilis PB6 on thyroid activity and histomorphometry, iron profile and blood haematology of quail

The purpose of this study was to assess the effects of dietary humate substances (HS) and CloSTAT (Bacillus subtilis PB6) on the thyroid activity and histology, iron profile, blood haematology and performance of growing Japanese quail. A total of 216 unsexed 7-day-old quail chicks were randomly assigned to six groups. The first group was fed a basal diet (BD) without any additives (control); the 2nd group received BD plus 0.05% CloSTAT, the 3rd and 4th groups were given BD plus 0.4% and 0.8% HS, respectively; and the 5th and 6th groups were administered BD plus CloSTAT + 0.4% HS and BD plus CloSTAT + 0.8% HS, respectively. The results showed that the growth performance was improved with the addition of CloSTAT alone or in combination with 0.4% HS compared with the control. Haematological parameters, iron level and transferrin saturation % were significantly (p < 0.001) increased by feeding HS compared with the control group. Serum thyroxin and triiodothyronine levels were significantly (p = 0.001) increased by adding CloSTAT relative to the control. Supplementation of 0.8% HS caused deterioration in histomorphometry parameters of the thyroid gland, but these parameters were improved in response to CloSTAT compared with the control. In conclusion, dietary B. subtilis PB6 as CloSTAT or CloSTAT + 0.4% HS supplementation may be efficacious in enhancing the growth performance and boosting the thyroid activity of growing Japanese quail. Moreover, the addition of 0.4% or 0.8% HS to quail diets boosted their iron profile and haematological parameters.

A case-control study on the association of mineral elements exposure and thyroid tumor and goiter

Thyroid tumor and thyroid goiter are prevalent disease around the world. In this case-control study, we investigated the association between exposure to a total of twelve mineral elements and thyroid disease as well as thyroid functions. Participants with thyroid tumor or goiter (N = 197) were matched with a healthy population (N = 197) by age (± 2 years old) and same sex. Questionnaires were used to collect data about the demographic characteristics and information of subjects. Serum and urine samples were collected simultaneously for each of the subjects. Mineral elements, iodine level of urine and levels of the total seven thyroid function indexes in serum were detected respectively. Conditional logistic regression was applied to estimate the associations between mineral elements and the risk of thyroid tumor and goiter through single-element models and multiple-element models. Multiple linear regression was used to evaluate relationships between mineral elements and percentage changes of thyroid functions. Higher concentrations of mineral elements in the recruited population were found in this study than other comparable studies, and the levels of chromium (Cr), manganese (Mn), nickel (Ni), arsenic (As), cadmium (Cd), selenium (Se), antimony (Sb), thallium (Tl) and lead (Pb) in the case group were lower than the control group. According to the single-element models, Cr, Mn, Ni, Sb and Tl showed significant negative associations with the risk of thyroid tumor and goiter, and, Cd showed nonmonotonic dose response. Cd and mercury (Hg) showed a nonmonotonic percentage change with T4, while Tl was associated with the increased FT4 in the control group. Therefore, Cd, Hg and Tl may disturb the balance of thyroid function to some extent, and Cr, Mn, Ni, Cd, Sb, and Tl may become potential influencing factors for the risk of thyroid tumor and goiter.

Association between blood lead levels and metabolic syndrome considering the effect of the thyroid-stimulating hormone based on the 2013 Korea National health and nutrition examination survey

Imbalances in thyroid-stimulating hormone (TSH) levels are associated with metabolic syndrome (MetS), and the underlying mechanism is partly in alignment with that of lead exposure causing MetS. Many studies have reported the association between lead exposure and MetS, but no study has considered the possibility of TSH mediating lead's effect on MetS. Therefore, we aimed to examine the association between lead exposure and MetS considering TSH as a partial mediator. The data of 1,688 adults (age ≥19 years) from the Korea National Health and Nutrition Examination Survey in 2013 were analyzed. The prevalence of MetS in the Korean population was 21.9%, and the geometric mean of blood lead and serum TSH levels were 1.96 μg/dL and 2.17 μIU/mL, respectively. The associations between blood lead levels, serum TSH levels, and MetS were determined through a multiple logistic regression analysis. Blood lead levels were positively associated with high TSH levels (upper 25%) with an odds ratio (OR) and 95% confidence interval (CI) of 1.79 (1.24, 2.58) per doubled lead levels. The increase in blood lead and serum TSH levels both positively increased the odds of developing MetS. The OR of MetS per doubling of blood lead level was 1.53 (1.00, 2.35), and was not attenuated after adjusting for TSH levels. These findings suggest that higher levels of blood lead are positively associated with serum TSH levels and MetS. By exploring the role of TSH as a partial mediator between lead and MetS, we verified that lead exposure has an independent relationship with MetS, regardless of TSH levels.

Significance of arsenic and lead in Hashimoto's thyroiditis demonstrated on thyroid tissue, blood, and urine samples

Our previous investigation showed significantly increased arsenic (As) content in thyroid tissue samples of patients with Hashimoto's thyroiditis (HT). This research aimed to extend previous findings and provide reliable insight into the close relationship between As and other trace elements with HT by considering a greater number of thyroid tissue samples, accompanied by blood and urine samples. The essential trace elements for thyroid homeostasis (Mn, Cu, Zn, Se) and the main threatening toxic trace elements (Ni, As, Pb, Cd, U) was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Relevant parameters that could affect the concentration of trace elements were considered. This research showed that there was a difference in the elemental profile between HT and control samples. The most important findings were related to the elevated As and Pb content in the thyroid tissue and HT blood samples. The obtained negative correlations between As and Pb with Se may explain the antagonistic effect of As and Pb on the extrusion of essential Se from the HT tissue. The reduced Se content in the blood and its increased content in urine samples may further confirm this hypothesis and explain the lack of Se in HT. Furthermore, the reported results may highlight the unresolved molecular basis of HT and could indicate the role of trace element effects on thyroid homeostasis.

Evaluation of trace metals in thyroid tissues: Comparative analysis with benign and malignant thyroid diseases

Evaluation of trace metals at level of solid tissue can provide better information than blood or urine and, therefore, could highlight the role of metals in the etiology of organ-specific disease. The current study aimed to establish the baseline content of four essential (Mn, Cu, Zn, Se) and four toxic metals (As, Cd, Pb, U) in the healthy thyroid tissues (HTTs) by considering sex, age and smoking habits. A further aim was to examine whether differences in the content of metals exist in regard to the thyroid diseases, such as benign tumor (BT), Hashimoto's thyroiditis (HT), multinodular goiter (MNG) and thyroid cancer (TC). A total number of investigated tissue samples were 423. All metals were quantified by inductively coupled plasma-mass spectrometry (ICP-MS). It was found that the content of Cu and U was higher in HTTs of women, while the content of Zn was higher in HTTs of men. Increased content of Zn and decreased content of U was found in the group of HTTs above 50 years compared to a younger group (<50 years). Increased content of Cd, Pb and U distinguish smokers from the non-smokers. In comparison with other population groups worldwide, investigated Serbian population had up to 15 times reduced content of Se. Despite the difference in metal's profile according to biological variables, this study also demonstrated, for the first time, that each thyroid disease has its unique metal's profile. The most altered metal's content was found in tissues with HT. Contrarily, the greatest similarity in metal's content with HTTs was found in BT tissues. Based on the increased content, metal's that dominantly discriminated HTTs from the HT, MNG and TC was As, Pb and Cd, respectively. Reported results could highlight the role of toxic and essential trace metals in the not very well clarified etiology of thyroid diseases and, moreover, could provide a molecular basis for pathophysiological changes of metal's hazardous effects on thyroid health at the tissue level.