Environmental arsenic exposure and its toxicological effect on thyroid function: a systematic review

Objectives This study was performed to review epidemiological evidence related to Arsenic (As) effects on the thyroid function by focusing on the serum thyroid hormone concentration. Content As, one of the main pollutants, has been recognized as an endocrine-disrupting agent that may affect the function of thyroid as shown by experimental studies. Summary This systematic study indicates the association between As exposure and thyroid dysfunction. The studies have shown an association between serum and urine concentration of arsenic and thyroid dysfunction. Most of them reported the association between increase in the serum or urine As levels and decrease in the triiodothyronine (T3) and thyroxine (T4), and also elevation in the thyrotropic hormone (TSH) levels. Outlook Our findings related to the effects of As on the function of thyroid in humans are still limited and future studies should be done to address this question.

Association between thyroid autoimmunity and ovarian reserve in women with hypothyroidism

Background The ovarian function and therefore the ovarian reserve may be compromised by the pathogenesis of autoimmune diseases of which, Hashimoto’s thyroiditis (HT) is the most common in women of reproductive age. Furthermore, a prolonged reduction in thyroid hormone concentration results in a broad spectrum of reproductive alteration. Previous reports in the literature have been controversial regarding the impact of hypothyroidism and alterations in the ovarian reserve. Thus, this prospective and comparative study aimed to evaluate the association of hypothyroidism with low ovarian reserve. Materials and Methods A subset of 27 patients with primary autoimmune hypothyroidism were compared to healthy women. The ovarian reserve was assessed through the anti-Mullerian hormone (AMH) and the antral follicle count (AFC). Results Overall, the two groups did not display significant differences in length of their menstrual cycles neither in the AMH serum levels nor the AFC. Conclusions No significant alteration was found in the ovarian reserve of women with HT.

Very rare case of Graves’ disease with resistance to methimazole: a case report and literature review

Background Methimazole (MMI) is used to treat hyperthyroidism in Graves’ disease. It is rare to encounter patients in whom hyperthyroidism cannot be controlled using high doses of MMI. Case presentation: A 21-year-old woman was referred to our hospital because of MMI-resistant Graves’ disease. Although her MMI dose had been increased to 120 mg/day, her serum thyroid hormone concentration was too high to be measured. Additional therapy with lithium carbonate, and then with dexamethasone and inorganic iodine, was initiated. After 14 days, the patient’s serum thyroid hormone concentration normalized, while she was taking 150 mg/day MMI, 800 mg/day lithium carbonate, 6 mg/day dexamethasone and 306 mg/day inorganic iodine, and total thyroidectomy was then performed. The patient was discharged 8 days after the thyroidectomy and experienced no major complications. Conclusions We have presented a rare case of Graves’ disease that was resistant to high-dose MMI. Combination therapy of MMI with lithium carbonate, dexamethasone and inorganic iodine may represent a therapeutic option for the preoperative preparation of patients with MMI-resistant Graves’ disease.

Analysis of electrocardiographic and echocardiographic parameters in healthy Rhodesian ridgebacks

The aim of the study was the analysis of electrocardiographic and echocardiographic parameters in Rhodesian ridgebacks. A group of 16 Rhodesian (9 females, 7 males) in age ranges from 2 to 9 (6.2 ± 2.91) and weighing from 38kg to 56kg (44.66 ±5.78) were divided into two groups based on thyroid hormone concentration in their blood. The first group consists of 12 healthy Rhodesian ridgebacks (8 females, 4 males), and the second of 4 dogs with hypothyroidism (3 females, 1 male). Data obtained from ECG and echocardiographic examination was gathered in a computer database and submitted for analysis. The reference values were determined for ECG and echocardiographic parameters. The difference between groups was evaluated with the U Mann-Whitney test. Analyses were conducted at a significance level of p

Thyroid function tests and its interpretation

Thyroid diseases are among the most prevalent of medical conditions. In the patients with obvious features of hypothyroidism or hyperthyroidism thyroid function tests only confirm the diagnosis. Though TSH is widely used as a screening test in suspicion with thyroid disorder, many times TSH alone may be misleading. In this situation TSH along with T4 and T3 should be performed which will resolve the problem. However, thyroid function tests may not concord with each other. Discordant results between TSH, T4 and T3 may be because of various conditions like subclinical hypo- or hyperthyroidism, non-thyroidal illness, drugs etc. Beside that antibody interference and special condition like pregnancy may alter the thyroid hormone concentration. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10318 Journal of Pathology of Nepal (2014) Vol. 4, 584-590

A Clinical Review of the Association of Thyroid Stimulating Hormone and Cognitive Impairment

Clinical and subclinical hypothyroidism as well as overt hyperthyroidism in middle-aged and elderly adults are both associated with decreased cognitive functioning as memory, reaction time, and visuospatial organization. Subclinical hyperthyroidism (SH) or low serum concentrations of TSH concentrations have been associated with dementia in previous epidemiological studies, but the association in the elderly has not been established. There is little or no consensus regarding how thyroid function is associated with cognitive performance in the elderly. In this focused review, we have performed an examination between eleven studies from the last five years examining the association between thyroid function and cognitive performance in elderly people, a group who is overrepresented among individuals with minor abnormalities in serum TSH and thyroid hormone concentration. Six of the studies showed a consistent finding of an association between SH with cognitive impairment or dementia. In general, taking into account the largest and most powerfully designed studies, there is a strong body of evidence supporting the association between SH and cognitive impairment. The scarce number of publications on these topics indicates the need of more research especially regarding longitudinal and interventional studies thus hopefully enabling confirmation or rejection of causality between TSH abnormalities and dementia.