Role Of Thyroid Dysfunction Research Articles

SAT463 Hormonal Contraceptive Use and Hypothyroidism Risk

Abstract Disclosure: S. Gloe: None. T.B. Carroll: Consulting Fee; Self; Corcept Therapeutics. Research Investigator; Self; Corcept Therapeutics, Novartis Pharmaceuticals. Introduction: Thyroid dysfunction is one of the most common endocrine disorders, with an estimated 4.3% of the US affected by subclinical hypothyroidism and 0.3% affected by overt hypothyroidism. Chronic autoimmune thyroiditis is the most common cause of hypothyroidism in the US and is estimated to affect 5-10x more women than men. Given this higher incidence in women, it is possible that hormonal difference or hormonal medications may play a role in thyroid dysfunction. Nearly 15% of women aged 15-49 use oral contraceptive pills (OCP) and 10.4% use other long-acting reversible hormonal contraceptives. A recent study showed a 25% increased prevalence of hypothyroidism in women with prior OCP use and in women with more than 10 years of OCP use the risk of developing hypothyroidism was nearly 4 times as high. Methods: Using the TriNetX database, four distinct groups of women aged 18-45 were identified using data from 1/1/2010 -1/1/2020. The four groups were EPC (n=5849), POC (n=5052), IUD (n=1000), and controls without prior hormonal contraception use (n = 6677). Demographic data, date of diagnosis of hypothyroidism, alcohol use, tobacco use, and BMI was obtained for each subject. Exclusion criteria included thyroidectomy (partial or total), lack of sufficient medication data, and a hypothyroidism diagnosis prior to or within 90 days of the first contraceptive medication order. A logistic model was then created accounting for known risk factors for the development of hypothyroidism (race/ethnicity, alcohol use, smoking, and BMI).Results: Initial comparison of treatment groups to controls demonstrated an no difference in risk of developing hypothyroidism for the EPC group (OR=1.18, p=0.2), but the POC and IUD groups had decreased risk of hypothyroidism (OR=0.39, p=<0.001 and OR=0.45, p=0.029, respectively). Using the logistic model, all groups demonstrated a decreased risk of hypothyroidism as compared to the control group (EPC: OR=0.3, p=<0.001, POC: OR=0.14, p=<0.001, IUD: OR=0.12, p=<0.001). Additionally, individuals identifying as Black/African Americans were less likely to develop hypothyroidism when compared to white/Caucasian subjects (OR=0.25, p=<0.001). Finally, BMI showed a fairly weak but significant association with development of hypothyroidism (OR=1.04, p=< 0.0001). Conclusion: Contrary to prior research, our data suggests a potential protective effect against the development of hypothyroidism for EPC, POC, and IUD use. The data also confirms prior studies showing a lower incidence of hypothyroidism in individuals who identify as Black/African American and perhaps those with lower BMI. Presentation Date: Saturday, June 17, 2023

Thyroid Disorders and Movement Disorders-A Systematic Review.

There is overlap between movement disorders and neuroendocrine abnormalities. To provide a systematic review on the association of thyroid dysfunction and movement disorders. Thyroid physiological function and classical thyroid disorders highlighting typical and atypical manifestations including movement disorders, as well as diagnostic procedures, and treatments are discussed. Hypothyroidism may be associated with hypokinetic and hyperkinetic disorders. There is debate whether their concomitance reflects a causal link, is coincidence, or the result of one unmasking the other. Hypothyroidism-associated parkinsonism may resemble idiopathic Parkinson's disease. Hypothyroidism-associated hyperkinetic disorders mainly occur in the context of steroid-responsive encephalopathy with autoimmune thyroiditis, that is, Hashimoto disease, mostly manifesting with tremor, myoclonus, and ataxia present in 28-80%, 42-65% and 33-65% in larger series. Congenital hypothyroidism manifesting with movement disorders, mostly chorea and dystonia, due to Mendelian genetic disease are rare.Hyperthyroidism on the other hand mostly manifests with hyperkinetic movement disorders, typically tremor (present in three quarters of patients). Chorea (present in about 2% of hyperthyroid patients), dystonia, myoclonus, ataxia and paroxysmal movement disorders, as well as parkinsonism have also been reported, with correlation between movement intensity and thyroid hormone levels.On a group level, studies on the role of thyroid dysfunction as a risk factor for the development of PD remain non-conclusive. In view of the treatability of movement disorders associated with thyroid disease, accurate diagnosis is important. The pathophysiology remains poorly understood. More detailed case documentation and systematic studies, along with experimental studies are needed.

Evaluation of leptin serum concentration in cases of blood transfusion dependent Beta thalassemia and its relationship with thyroid dysfunction

Introduction and Aim: Thalassemia disorder is characterized by the body’s inability to produce hemoglobin. This is an inherited disorder and arises due to defects in one or more globin chains. Thalassemia patients have been associated with endocrine dysfunction leading to toxic and deleterious effects. In the present study, we aimed to correlate leptin levels in Transfusion-dependent beta-thalassemia (TDT) patients to their thyroid hormonal levels and hematological parameters. Materials and Methods: The study included 50 individuals (25 male and 25 female) aged 11-20 years with beta-thalassemia major and 20 healthy individuals (10 male, 10 females) aged 13-20 years as controls. All individuals included in the study were assessed for their BMI, complete blood count, serum ferritin and iron, thyroid function, leptin and ghrelin hormonal levels. Results: This study showed a low BMI in patients as compared to healthy individuals. A high increase in TSH and ferritin was found in patients of both genders as compared to controls. T4 significantly decreased in males and females as compared to control. Significant reduction in leptin levels was observed in both male and female patients. A positive correlation was observed between leptin and TSH in males while a negative correlation between leptin and T4 was observed in females. A significant positive correlation was seen between leptin and T4 and between TSH and T4. BMI in males and female significant low compared to control. Conclusion: Leptin probably plays an important role in thyroid dysfunction. Serum leptin, ferritin and thyroid hormonal levels in patients could be used as a guide in predicting hormonal modulation in major beta thalassemic patients.

Structural binding perspectives of common plasticizers and a flame retardant, BDE-153, against thyroxine-binding globulin: potential for endocrine disruption.

The human exposure to diverse endocrine-disrupting chemicals (EDCs) has increased dramatically over several decades with very adverse health effects. Plasticizers and flame retardants constitute important classes of EDCs interfering in endocrine physiology including the thyroid function. Thyroxine (T4) is an important hormone regulating metabolism and playing key roles in developmental processes. In this study, six phthalate and nonphthalate plasticizers and one flame retardant (BDE-153) were subjected to structural binding against thyroxine-binding globulin (TBG). The aim was to understand their potential role in thyroid dysfunction using structural binding approach. The structural study was performed using Schrodinger's induced fit docking, followed by binding energy estimations of ligands and the molecular interaction analysis between the ligands and the amino acid residues in the TBG ligand-binding pocket. The results indicated that all the compounds packed tightly into the TBG ligand-binding pocket with similar binding pattern to that of TBG native ligand, T4. A high majority of TBG interacting amino acid residues for ligands showed commonality with native ligand, T4. The estimated binding energy values were highest for BDE-153 followed by nonphthalate plasticizer, DINCH, with values comparable with native ligand, T4. The estimated binding energy values of other plasticizers DEHP, DEHT, DEHA, ATBC, and TOTM were less than DINCH. In conclusion, the tight docking conformations, amino acid interactions, and binding energy values of the most of the indicated ligands were comparable with TBG native ligand, T4, suggesting their potential for thyroid dysfunction. The results revealed highest potential thyroid disruptive action for BDE-153 and DINCH.

SARS-CoV-2: Emerging Role in the Pathogenesis of Various Thyroid Diseases.

Coronavirus disease-2019 (COVID-19) is asymptomatic in most cases, but it is impartible and fatal in fragile and elderly people. Heretofore, more than four million people succumbed to COVID-19, while it spreads to every part of the globe. Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) induces various dysfunctions in many vital organs including the thyroid by utilizing ACE2 as a receptor for cellular entry. Emerging reports clearly show the involvement of SARS-CoV-2 in diverse thyroid disorders. Thus, this review article aims to review comprehensively all the recent developments in SARS-CoV-2-induced pathogenesis of thyroid diseases. The review briefly summarizes the recent key findings on the mechanism of SARS-CoV-2 infection, the role of ACE2 receptor in viral entry, SARS-CoV-2-activated molecular signaling in host cells, ACE2 expression in the thyroid, cytokine storm, and its vital role in thyroid dysfunction and long-COVID in relation to thyroid and autoimmunity. Further, it extensively discusses rapidly evolving knowledge on the potential part of SARS-CoV-2 in emerging various thyroid dysfunctions during and post-COVID-19 conditions which include subacute thyroiditis, Graves' diseases, Hashimoto’s thyroiditis, thyrotoxicosis, and other recent advances in further discerning the implications of this virus within thyroid dysfunction. Unraveling the pathophysiology of SARS-CoV-2-triggered thyroid dysfunctions may aid pertinent therapeutic options and management of these patients in both during and post-COVID-19 scenarios.

Correlation of thyroid hormone profile and acute physiology and chronic health evaluation II (APACHE II) score with the survival in sepsis in a tertiary care centre

Background: Thyroid hormone plays a pivotal role in the adaptation of metabolic function to stress and critical illness like sepsis. Thyroid dysfunction is associated with increased mortality in sepsis. The role of thyroid dysfunction as a prognostic marker in sepsis remains unclear.
 Aims and Objectives: To correlate the baseline thyroid function tests with APACHE II score and mortality in adult patients admitted with sepsis in Intensive Care Unit (ICU).
 Materials and Methods: This was a cross sectional, observational study done for a period of one year from September 2019 to September 2020 in a tertiary care referral hospital. Patients admitted with sepsis to ICU were scored on admission using APACHE II score. Blood was sent for thyroid function tests on admission. Patients were divided into survivors and non-survivors based on the outcome. Statistical analysis was done by calculating mean values, Fisher’s exact test and Pearson’s correlation.
 Results: A total of 52 patients were included. The mean age was 55.65± 18.55 years with a male predominance (M: F=1.4:1). Pneumonia was the commonest cause of sepsis in the study (20 patients,38.5%). Mortality was seen in 20 patients (38.5%) The mean values of thyroid hormones were lower in non-survivors. APACHE II Score was higher among the non-survivors as compared to survivors. (21.7±5.571 vs 19.78 ± 5.939, p value>0.05). Thyroid hormones (T3, T4, FT3, FT4) had a negative correlation with APACHE II score in non-survivors. TSH had significant positive correlation with APACHE II score in non-survivors (p value=0.027).
 Conclusion: Thyroid hormone levels did not correlate significantly with APACHE II score and mortality among the non-survivors of sepsis.

Effects of thyroid hormone imbalance on colorectal cancer carcinogenesis and risk - a systematic review.

Colorectal cancer (CRC) is the second leading cause of cancer-related death. The prevalence of colorectal neoplasm is increasing. Many studies have shown that thyroid dysfunction may be connected with the higher risk of pancreatic and breast cancer, but only a few described the role of thyroid dysfunction and thyroid hormone (TH) replacement in the development and risk of CRC. The aim of this study is to summarise all findings and potentially elucidate the connection between TH imbalance and colorectal cancer. The systematic review was conducted according to PICO and PRISMA guidelines. We searched MEDLINE, ClinicalTrials.gov, www.clinicaltrialsregister.eu, and Cochrane Library databases using the following keywords: "((((thyroid OR hypothyroidism OR hyperthyroidism OR levothyroxine OR hashimoto OR graves OR thyroidectomy)) AND (colon OR colorectal OR CRC)) NOT hashimoto[Author]) NOT graves[Author])". No filters were used. Of total of 3054 articles identified by the search strategy, 11 met PICO criteria and were included into the review. Four of those were on cell lines and seven were human studies. Analysis of the included studies revealed an elevated risk of CRC in patients with hypothyroidism with aORs ranging from 1.16 (95% CI: 1.08-1.24, p < 0.001) to 1.69 (95% CI: 1.21-2.36, p = 0.002). Moreover, TH replacement therapy has a protective effect for CRC risk with aOR ranging from 0.60 (95% CI: 0.44-0.81, p = 0.001) to 0.92 (95% CI: 0.86-0.98, p = 0.009). THs seem to play a role in colorectal carcinogenesis. Further studies are warranted to define the exact role of thyroid hormone imbalance in prevention and treatment of CRC.

Role of thyroid dysfunction in patients with menstrual disorders

Role of thyroid dysfunction in patients with menstrual disorders

High prevalence of HCV (GT4)-related TSH abnormality among 13402 Egyptian patients treated with direct acting antiviral therapy.

HCV is associated with several extra hepatic diseases including thyroid dysfunction. This study aims at evaluating prevalence of thyroid dysfunction and its possible predictors in a large cohort of HCV GT4-infected patients, and the role of thyroid dysfunction as a predictor of response in the setting of direct acting antivirals (DAAs). Patients registered on the web-based registry system to receive therapy for chronic HCV in Beheira governorate viral hepatitis specialized treatment center affiliated to the National committee for control of viral hepatitis (NCCVH), Ministry of health, Egypt in the period from January 2015 to October 2016. Their data were exported and analyzed for the prevalence of thyroid dysfunction and its associated variables. Out of 13,402 patients, 2833 (21.1%) had elevated TSH level>4.5mIU/l (hypothyroidism). Female gender (62.7%), older age, higher FIB4, AST, and BMI and lower albumin were significantly associated with elevated TSH level on univariate analysis, while liver stiffness measured by fibroscan was not significantly associated. On the other hand, 466 patients (3.5%) showed low TSH level<0.4mIU/l (hyperthyroidism). Older age (median 52years) and male gender (51.5%) were the only significantly associated variables. No association was found between SVR and baseline TSH level. Follow-up of 236 patients after SVR revealed improvement in TSH level in 80% of them. Hypothyroidism is prevalent in patients with chronic HCV GT4, and is influenced by patient gender and age. Pretreatment TSH does not affect SVR after DAAs. Despite limited data SVR achievement after DAAs improves thyroid dysfunction.

The Role of Thyroid Dysfunction and The Importance of Conducting Regular Thyroid Function Tests in patients with PCOS: A Narrative Review

Polycystic Ovary Syndrome (PCOS) and thyroid pathology, the two endocrine abnormalities have been connected to each other since quite a long while, however, the majority of the scientists have researched the relationship amongst hypothyroidism and PCOS, a backward relationship of PCOS prompting thyroid brokenness is presently being tested into. Consequently this investigation went for investigating the likelihood of improvement of thyroid brokenness in ladies with PCOS. Thyroid hormones effectively affect the regenerative arrangement of the human female. Modification in thyroid capacity, especially hypothyroidism, can cause ovulatory brokenness and prompt impeded female richness. Hypothyroidism and PCOS are frequently joined by expanded serum free testosterone, luteinizing hormone (LH) and elevated cholesterol. At the point when the ovaries of hypothyroid women with PCOS have seen with an ultrasound, an expansion in ovarian volume and the presence of reciprocal multicystic ovaries are frequently obvious. At the point when thyroid hormone substitution treatment is started, notwithstanding settling thyroid hormone levels, ovarian sores relapse and ovarian volume are diminished. In this way ladies with PCOS could be at a hazard for the advancement of thyroid issue and biochemical screening of all the thyroid parameters including that of thyroid autoantibodies is of most extreme significance in such people.

Роль тиреоидной дисфункции в генезе гестационных и перинатальных осложнений

Роль тиреоидной дисфункции в генезе гестационных и перинатальных осложнений

Type II 5’Deiodinase Thr92Ala Polymorphism Is Associated with CVD Risk among Type 2 Diabetes Mellitus Patients

Background: The physiological ratio of T3:T4 is essential to trigger the biological actions, since the T3:T4 ratio is efficiently regulated by extrathyroidal selenodeiodinases. Thr92Ala is a common variant in the DIO2 gene, which may have an implication in decreased phenotypic expression, but previous studies had conflicting outcomes. Consequently, we have undertaken this study to understand the effect of this SNP on CVD risk among type 2 diabetics. Methods: We included 130 T2DM patients without signs of CVD as controls and 106 proved CVD patients with T2DM as cases. The entire subjects were genotyped for Thr92Ala of DIO2 gene. FBG, lipid & thyroid profile, HDL sub-fractionations, type II deiodinase, malondialdehyde, paraoxonase, and superoxide dismutase were measured according to standard procedures. Results: The mean DIO2 levels in Ala/Ala genotypes were significantly lower than Thr/Thr + Thr/Ala genotypes (122 ± 39 ng/ml & 161 ± 32 ng/ml respectively). The thyroid profile was normal in all the subjects; merely it was altered significantly among the Ala/Ala genotypes when compared with Thr/Thr + Thr/Ala genotypes. Remarkably, there is a significant decrease in T3:T4 and HDL3:HDL2 ratios and paraoxonase activity among Ala/Ala genotypes when compared with Thr/Thr + Thr/Ala genotypes. TSH and T4 levels were near to upper normal levels among Ala/Ala genotype. HDL3:HDL2 ratio is positively correlated with paraoxonase activity among Thr/Thr + Thr/Ala genotypes (r = 0.36, p 2:HDL2 ratio and paraoxonase activity are altered among the Ala/Ala genotype. Thus, Ala/Ala genotype plays a key role in thyroid dysfunction, dyslipidemia and the development of CVD risk among type 2 diabetics.

Association of Type II 5¢ Monodeiodinase Thr92Ala Polymorphism and Cardiovascular disease risk in Type 2 Diabetes Mellitus

Background: The physiological ratio of T3:T4 is essential to trigger the biological action since it is efficiently regulated by extrathyroidal selenodeiodinases. Thr92Ala is a common variant in the DIO2 gene which may have implication in decreased phenotypic expression. This study intends to find the effect of the SNP on CVD risk in type 2 diabetes. Materials and Methods: We included 130 T2DM patients without signs of CVD as controls and 106 CVD patients with T2DM as cases. All were genotyped for Thr92Ala of DIO2 gene. Fasting blood glucose lipid and thyroid profile, HDL subfractionations, type II deiodinase, malondialdehyde, paraoxonase, and superoxide dismutase were measured Results: The mean D2 level in Ala/Ala individuals was significantly lower than in Thr/Thr or Thr/Ala genotypes (122±39 VS 161±32ng/ml). The thyroid profile was significantly altered among Ala/Ala genotypes when compared with Thr/Thr and Thr/ Ala genotypes. There is a significant decrease in T3:T4 ratio, HDL3:HDL2 ratio and paraoxonase activity among Ala/Ala homozygote’s when compared with the/Thr+Thr/Ala genotypes. HDL3:HDL2 ratio is positively correlated with paraoxonase activity among Thr/Thr+Thr/Ala genotypes (r=0.36, p<0.05). Conclusion: Ala/Ala genotype plays a key role in thyroid dysfunction, dyslipidemia and the development of CVD risk in those which type 2 diabetes. Key-words: DIO2 Thr92Ala; Thyroid hormones; Dyslipidemia; Oxidative stress; Type 2 diabetes mellitus; CVD risk

Role of Thyroid Dysfunction in Patients with Menstrual Disorders in Tertiary Care Center of Walled City of Delhi.

To study the prevalence of thyroid disorders and its correlation with menstrual disorders. 100 women aged between 15 and 45years who attended gyne OPD in Kasturba Hospital, Delhi, were included for this cross-sectional study. The study group comprised 50 patients presented with menstrual complaints. The control group consisted of 50 women of same age group with complaints other than menstrual disorders. Thyroid function tests, anti-TPO antibody estimation, and endometrial sampling were done in all patients. In patients with menstrual disorders, 44% had thyroid disorders in which subclinical hypothyroidism was prevalent in 20%, overt hypothyroidism in 14%, and overt hyperthyroidism in 8% of the women. Autoimmune thyroid antibodies were present in 30% patients of women with menstrual disorders. On endometrial sampling, hypothyroid patients mainly had proliferative endometrium (42.85%) whereas hyperthyroid had atrophic endometrium (60%). Thyroid dysfunction is an important causative etiology of menstrual abnormalities. Assessment of thyroid function should be done in all patients with menstrual disorders to avoid unnecessary interventions like curettage and hysterectomy.

Individual plasma ghrelin changes in the same patients in hyperthyroid, hypothyroid and euthyroid state

Ghrelin is a multifunctional peptide of widespread expression. Since it has been shown to influence energy homeostatis, its potential role in thyroid dysfunction may have clinical significance. In this study, plasma ghrelin changes have been analyzed in the same patients in three different thyroid states for the first time. The study group consisted of 16 patients who had been diagnosed with hyperthyroidism, were treated with radioiodine, developed hypothyroidism after treatment, and finally became euthyroid on l-thyroxine substitution. In the initial state of hyperthyroidism plasma ghrelin levels correlated negatively with fT3 and fT4. In hypothyroidism ghrelin concentration increased significantly (p<0.05). Although the mean value of plasma ghrelin tended to decrease in the euthyroid state, the individual difference between hypothyroidism and euthyroidism was not significant. Plasma ghrelin in euthyroidism was still significantly higher than in hyperthyroidism (p<0.05), and correlated positively with ghrelin levels in hyperthyroidism and hypothyroidism. In our opinion, plasma ghrelin fluctuations may reflect metabolic changes in patients with thyroid dysfunction. Moreover, it cannot be excluded that in thyroid disorders ghrelin acts as a compensatory factor, helping to balance metabolic disturbances.

HIV and thyroid dysfunction

Human Immunodeficiency virus (HIV) infection and Acquired Immunodeficiency Syndrome (AIDS) are associated with dysfunction of many endocrine organs and their axis. HIV infectivity leads to altered metabolism, poor oral intake and increased prevalence of weight loss and wasting which may have a role in thyroid dysfunction. Overt thyroid dysfunction occurs at similar rates as the general population while subclinical disease such as nonthyroidal illness (sick euthyroid syndrome), subclinical hypothyroidism and isolated low T4 levels are more frequent. Moreover, HAART therapy can complicate thyroid function further through drug interactions and the immune reconstitution inflammatory syndrome (IRIS). In this review we report the common thyroid dysfunctions associated with HIV before and after HAART therapy. We discuss presentation, diagnostic work up, treatment and follow up in each condition.

Maternal Hypothyroidism and Pregnancy Loss: Awaiting Firm Recommendations on Testing and Treatment

Maternal Hypothyroidism and Pregnancy Loss: Awaiting Firm Recommendations on Testing and Treatment

Improvement of Thyroid Function in Hypothyroid Patients with Rheumatoid Arthritis After 6 Months of Adalimumab Treatment: A Pilot Study

Rheumatoid arthritis (RA) is characterized by high levels of cytokines such as tumor necrosis factor (TNF). TNF appears to have an etiologic role in thyroid dysfunction, and thyroid dysfunction is a common comorbidity in RA. Anti-TNF treatment might limit thyroid dysfunction. Thus, changes in thyroid hormones were studied during TNF-blocking therapy in patients with RA. At baseline and after 6 months' treatment with adalimumab, thyroid function [thyroid-stimulating hormone (TSH), free thyroxine (fT4), and antibodies against thyroid peroxidase (TPOabs)] were assessed in 138 consecutive adalimumab-treated patients with RA who were naive for TNF-blocking agents. Patients were categorized as hypothyroid, hyperthyroid, or euthyroid. In these groups, changes in thyroid function were determined. Prevalences of hypothyroidism, hyperthyroidism, and TPOabs were 13%, 5%, and 15%, respectively. After 6 months, TPOabs decreased from 267 to 201 IU/ml (p = 0.048). In hypothyroid patients without concomitant L-thyroxine, a trend for declining levels of TSH was observed. Subgroup analysis revealed that in patients who were hypothyroid and TPOabs-positive and L-thyroxine-naive, TSH levels decreased significantly, from 12.5 (interquartile range 6.7-18.4) to 7.1 (interquartile range 4.9-13.8) mU/l (p = 0.043). Anti-TNF treatment improves thyroid function in hypothyroid patients with RA (especially in those who are L-thyroxine-naive and TPOabs-positive), providing further evidence that inflammatory cytokines such as TNF have a pathogenic role in thyroid dysfunction.

Venous Thromboembolism in Patients Hospitalized With Thyroid Dysfunction

The objective of this investigation is to explore a possible role of thyroid dysfunction in venous thromboembolism (VTE). The number of patients discharged from short-stay nonfederal hospitals in the United States, from 1979 to 2005, with a diagnostic code for hypothyroidism or hyperthyroidism, pulmonary embolism (PE), and deep venous thrombosis (DVT) was obtained from the National Hospital Discharge Survey (NHDS). Among 19,519,000 hospitalized patients discharged with a diagnosis of hypothyroidism from 1979 to 2005, 119,000 (0.61%) had PE. Among patients with no thyroid dysfunction, PE was diagnosed in 3,372,000 of 908,805,000 patients (0.37%; relative risk = 1.64, 95% CI 1.63-1.65). Deep venous thrombosis was diagnosed in 1.36% of hypothyroid patients and in 0.84% of patients with no thyroid dysfunction (relative risk = 1.62, 95% CI 1.61-1.62). The relative risk of PE in patients with hypothyroidism was highest in patients <40 years of age (relative risk = 3.99) and the relative risk of DVT was also highest in patients <40 years (relative risk = 2.25). Hyperthyroidism was not associated with an increased risk of VTE (relative risk = 0.98, 95% CI = 0.96-1.01). In conclusion, an increased risk of PE, DVT, and VTE was shown in patients with hypothyroidism but not hyperthyroidism. Antithrombotic prophylaxis in patients with severe hypothyroidism, however, should be viewed with caution because of a possible hyperfibrinolytic state in such patients.

Thyroid dysfunction and headache

An observational study of thyroid function tests performed in patients with headache prior to referral to a neurological clinic found no headache cases attributable to either hypothyroidism or hyperthyroidism. The role of thyroid dysfunction in the aetiology of hedache remains uncertain.