Hypertension in Thyroid Disorders

Thyroid hormone deiodinases response in brain of spontaneausly hypertensive rats after hypotensive effects induced by mandibular extension

PURPOSE

The deiodinases activate or inactivate the thyroid hormones (TH) in virtually all tissues in both physiological and pathological conditions. The three deiodinases, DIO1, DIO2, and DIO3, have different catalytic functions and regulate TH tissue distribution. The aim of the present study was to evaluate the modulation of gene expression of the deiodinases and TH transporters and protein levels of DIO1 in parietal and frontal areas of cerebral cortex of spontaneously hypertensive rats (SHRs), after two successive mandibular extensions (ME).

METHODS

ME was performed on anesthetized rats by a dilatator appropriately designed and real-time PCR and western blotting techniques were employed for gene expression and protein level study.

RESULTS

Mean blood pressure (MBP) significantly decreased in 2ME-treated rats when compared to sham-operated rats (p < 0.001) and this decrease lasted for the entire observation period. In gene expression analysis, in 2ME-treated rats we did not observe any significant variation of DIO1 and DIO3 with respect to the sham-operated rats. Differently, DIO2 gene expression significantly increased in frontal area of 2ME-treated rats, with respect to sham-operated rats (p < 0.01). Furthermore, in parietal area, protein levels of DIO1 in 2ME-treated rats were significantly higher than in sham-operated rats (p < 0.01). Moreover MCT8 and OATP1C1 both resulted significantly higher (p < 0.05 and p < 0.001) in sham frontal cortex.

CONCLUSION

In summary, our data on SHRs, while confirming the hypotensive effect of two MEs, show that the treatment also solicits the three deiodinases production in the cerebral cortex.

Multiscale simulations of left ventricular growth and remodeling

Cardiomyocytes can adapt their size, shape, and orientation in response to altered biomechanical or biochemical stimuli. The process by which the heart undergoes structural changes-affecting both geometry and material properties-in response to altered ventricular loading, altered hormonal levels, or mutant sarcomeric proteins is broadly known as cardiac growth and remodeling (G&R). Although it is likely that cardiac G&R initially occurs as an adaptive response of the heart to the underlying stimuli, prolonged pathological changes can lead to increased risk of atrial fibrillation, heart failure, and sudden death. During the past few decades, computational models have been extensively used to investigate the mechanisms of cardiac G&R, as a complement to experimental measurements. These models have provided an opportunity to quantitatively study the relationships between the underlying stimuli (primarily mechanical) and the adverse outcomes of cardiac G&R, i.e., alterations in ventricular size and function. State-of-the-art computational models have shown promise in predicting the progression of cardiac G&R. However, there are still limitations that need to be addressed in future works to advance the field. In this review, we first outline the current state of computational models of cardiac growth and myofiber remodeling. Then, we discuss the potential limitations of current models of cardiac G&R that need to be addressed before they can be utilized in clinical care. Finally, we briefly discuss the next feasible steps and future directions that could advance the field of cardiac G&R.

The importance of stratifying ischemic risk by using the Duke score in women with ischemic heart disease and hypothyroidism before inclusion in cardiovascular rehabilitation programs

Introduction: The relationship between abnormal thyroid function and coronary heart disease has been known for a long time, and particularly, hypothyroidism is associated with an increased risk of cardiovascular disease. The aim of this study was to evaluate the ischemic risk by using the Duke score in women with ischemic heart disease and associated hypothyroidism before inclusion in cardiovascular rehabilitation program. Materials and methods: We included in the study 150 female patients admitted to the Cardiology Department of the Clinical Rehabilitation Hospital Cluj-Napoca. All the patients included had ischemic heart disease and performed an exercise stress testing to evaluate the effort capacity and also to stratify the ischemic risk by calculating the Duke Score. After dosing the thyroid stimulating hormone (TSH) we divided the patients in two groups: with hypothyroidism and a control group. Results: Patients with hypothyroidism were more frequently hypertensive, (98% vs 87%, p-0.035), and they had diabetes mellitus in a higher proportion (51% vs 22%, p-0.005). HDL cholesterol was significantly decreased in the group of patients with hypothyroidism: 40.36±10.39mg/dl vs 44.85±10.29mg/dl (p-0.01). Regarding the ischemic risk assessed by the Duke score, the statistically significant differences between the two groups were registered only for the category of high-risk patients, 5.55% vs 18% (p-0.048). Also, the TSH value was higher in the group with high-risk Duke score, 4.21±3.73µIU/ml, compared to the moderate-risk score group, 1.95±1.12µIU/ml(p-0.05). Conclusion: In women with ischemic heart disease, assessing thyroid function can be useful to identify patients at high risk of ischemia. Patients with hypothyroidism tend to have a higher prevalence of cardiovascular risk factors, a higher ischemic risk objectified by the Duke score and more commonly multivascular coronary lesions. For these patients, the inclusion in cardiovascular rehabilitation programs is essential, but it is very important that the programs to be customized for each patient. Keywords: coronary heart disease in women, exercise ECG, Duke score, ischemic risk, hypothyroidism, cardiovascular rehabilitation programs

Association between thyroid cysts and hypertension by atherosclerosis status: a cross-sectional study

Our recent studies indicate that thyroid cysts have clinical implications. Thyroid cysts could have a positive effect on the supply of thyroid hormones. Both hyperthyroidism and hypothyroidism cause hypertension. Hypothyroidism, but not hyperthyroidism, is a risk factor for atherosclerosis. Therefore, thyroid cysts could be associated with hypertension, and atherosclerosis might influence the association between thyroid cysts and hypertension. To evaluate the clinical significance of thyroid cysts, a cross-sectional study was conducted with 1801 Japanese aged 40–74 years. Thyroid cysts were significantly positively associated with hypertension in participants without atherosclerosis. However, there was a significant inverse association in those with atherosclerosis. The potential confounding factor adjusted odd ratios and 95% confidence intervals (95% CIs) were 1.49 (95% CI 1.17–1.90) for participants without atherosclerosis and 0.49 (95% CI 0.24–0.98) for those with atherosclerosis. The present study demonstrates that thyroid cysts have clinical implications because thyroid cysts support thyroid hormone activity. Our findings provide sufficient evidence to develop a risk assessment for hypertension for the general population, even though further research is required.

Thyroid Dysfunction and Dysmetabolic Syndrome: The Need for Enhanced Thyrovigilance Strategies

Thyroid dysfunction (TD) is common in metabolic disorders such as diabetes mellitus (DM), cardiovascular disease (CVD), obesity, dyslipidemia, hyperuricemia, kidney and liver dysfunctions, and polycystic ovary syndrome (PCOS). Subclinical hypothyroidism (SHypo) worsens glycemic control in patients with DM, and these patients, especially those with Type-1DM, have higher prevalence of TD. Both TD and DM increase CVD risk. Even minor alteration in thyroid hormone (TH) levels can alter cardiovascular function. While hyperthyroidism increases systolic blood pressure and leads to high-output heart failure, hypothyroidism increases diastolic blood pressure and leads to low-output heart failure. Chronic subclinical hyperthyroidism (SHyper) and SHypo both increase the risk of hypertension, coronary artery disease (CAD) events, CAD deaths, and total deaths. SHyper alters cardiac morphology and function. SHypo causes dyslipidemia and endothelial dysfunction and increases the risk for weight gain and obesity. Overweight and obese patients often have hyperleptinemia, which increases the secretion of thyroid stimulating hormone (TSH) and induces TD. Dyslipidemia associated with TD can increase serum uric acid levels. Hyperuricemia promotes inflammation and may increase the risk for dyslipidemia, atherosclerosis, and CVD. TD increases the risk for developing chronic kidney disease. In nephrotic syndrome, proteinuria is associated with urinary loss of TH leading to TD. Some correlation between TD and severity of liver disease is also seen. TD and PCOS have common risk factors and pathophysiological abnormalities. Hypothyroidism must be excluded before diagnosing PCOS. Current guidelines do not strongly recommend thyroid screening in the presence of all metabolic disorders. However, pragmatic thyrovigilance is required. Clinicians must stay alert to signs and symptoms of TD, maintain high clinical suspicion, and investigate thoroughly. Drug-induced TD should be considered when TH levels do not match clinical findings or when patients are on medications that can alter thyroid function.

Thyroid cancer and its associated factors: A population-based case-control study

Considering the rising incidence and mortality of thyroid cancer (TC) worldwide, the aim of our study was to determine the risk factors for TC in a province with the highest incidence of TC in the country located at the South of Iran. A population-based case-control study was performed on 708 participants (361 new cases and 347 controls). The case participants were selected from the Iranian National Cancer Registry database. Frequency matched for gender and age, and the control participants were selected randomly from the neighborhood of the cases. Based on the results of multiple logistic regression analysis, benign thyroid diseases (eg, hyperthyroidism OR_yes/no = 14.06, 95% CI: 5.13-38.51), family history of TC (OR_yes/no = 3.54, 95% CI: 1.51-8.26), radiation exposure of the head (OR_yes/no = 1.92, 95% CI: 1.03-3.60), family history of thyroid diseases (OR_yes/no = 1.76, 95% CI: 1.19-2.62) and family history of other types of cancer (OR_yes/no = 1.67, 95% CI: 1.01-2.74), significantly increased the risk of developing TC. On the other hand, high blood pressure (OR_yes/no = 0.35, 95% CI: 0.19-0.64), higher education (OR_{college/illiterate} = 0.54, 95% CI: 0.30-0.96), consumption of unsaturated fat (OR_{unsaturated/saturated} = 0.59, 95% CI: 0.39-0.87) and being married (OR_{married/single} = 0.60, 95% CI 0.37-0.98) were found to be protective factors. Some community-based interventions, for example, reduction in radiation exposure and screening members of families with underlying thyroid diseases may help in preventing or early diagnosis of TC. More studies on the health effects of local herbs are highly recommended.

Blood pressure characteristics of subclinical hypothyroidism: an observation study combined with office blood pressure and 24-h ambulatory blood pressure

OBJECTIVE

To investigate the characteristics of blood pressure in subclinical hypothyroidism by combining office blood pressure and 24-h ambulatory blood pressure.

METHODS

A total of 3078 adults voluntarily participants were enrolled in this study between December 2017 and November 2019. Among 1431 of them who did not fit exclusion criteria, 104 patients were with subclinical hypothyroidism (S-HYPO group), and 1327 were euthyroid participants (euthyroid group). Office blood pressure measurement and 24-h ambulatory blood pressure monitoring were carried out to analyze the characteristics of blood pressure in subclinical hypothyroidism.

RESULTS

There was no statistical difference in office SBP and DBP between the S-HYPO group and the euthyroid group (P > 0.05). On the ambulatory blood pressure level, the daytime SBP, night-time SBP, night-time SBP, 24-h SBP and DBP in the S-HYPO group were significantly higher than those in the euthyroid group (P = 0.048, P = 0.002, P = 0.003, P = 0. 014, P = 0. 046, respectively), and the proportion of nondipper blood pressure in the S-HYPO group was higher than that in the euthyroid group. Comprehensive analysis of blood pressure inside and outside the joint clinic revealed that the S-HYPO group was independently related to sustained hypertension and masked hypertension but not to white-coat hypertension (P = 0.004, P = 0.002, P = 0.886, respectively). After adjusting for age, sex, BMI, and other confounding factors, the above differences were still statistically significant (P < 0.05).

CONCLUSION

The characteristics of blood pressure in subclinical hypothyroidism can be more accurately understood by combining office blood pressure and ambulatory blood pressure.

Association of thyroid hormones with blood pressure and arterial stiffness in the general population: The Dali study

Thyroid dysfunction plays a role in blood pressure (BP) regulation. However, the associations between thyroid function and BP and arterial stiffness in the general Chinese population without thyroid disease are unknown. This population-based cross-sectional study aimed to investigate the association between thyroid function and peripheral and central BP and arterial stiffness in Chinese individuals. After excluding those who had thyroid diseases or incomplete clinical measurements, this study included 691 participants. Of the participants, 444 (64.2%) were women and 215 (31.1%) had hypertension. After adjustment for covariates, serum FT3 was significantly associated with a higher pulse rate in both sexes. In men, each 2.72-fold increase in serum FT4 levels was associated with higher peripheral systolic BP (+10.82 mmHg, p = .005) and pulse pressure (+5.71 mmHg, p = .03). Each 2.72-fold increase in serum FT4 levels was associated with higher central systolic BP (+8.03 mmHg, p = .03) and pulse pressure (+3.89 mmHg, p = .05). In women, serum FT4 was only associated with a higher central pulse pressure (+2.96 mmHg, p = .04). After adjustment for covariates, serum FT4 was significantly associated with a faster cfPWV exclusively in men. Our study showed that serum FT4 is associated with higher peripheral and central BP and faster cfPWV in men, whereas serum FT3 is positively associated with a higher pulse rate in both sexes, indicating that the effects of thyroid function on BP and arterial stiffness are more significant in men than in women.

Increased nitro-oxidative stress toxicity as a major determinant of increased blood pressure in mood disorders

BACKGROUND

Hypertension, atherogenicity and insulin resistance are major risk factors of cardiovascular disorder (CVD), which shows a strong comorbidity with major depression (MDD) and bipolar disorder (BD). Activated oxidative and nitrosative stress (O&NS), inflammatory pathways, and increased atherogenicity are shared pathways underpinning CVD and mood disorders.

METHODS

The current study examined the effects of lipid hydroperoxides (LOOH), superoxide dismutase (SOD), nitric oxide metabolites (NOx), advanced oxidation protein products (AOPP), and malondialdehyde (MDA) on systolic (SBP) and diastolic (DBP) blood pressure in 96 mood disordered patients and 60 healthy controls.

RESULTS

A large part of the variance in SBP (31.6%) was explained by the regression on a z unit-weighted composite score (based on LOOH, AOPP, SOD, NOx) reflecting nitro-oxidative stress toxicity (NOSTOX), coupled with highly sensitive C-reactive protein, body weight and use of antihypertensives. Increased DBP was best predicted (23.8%) by body mass index and NOSTOX. The most important O&NS biomarkers predicting an increased SBP were in descending order of significance: LOOH, AOPP and SOD. Higher levels of the atherogenic index of plasma, HOMA2 insulin resistance index and basal thyroid-stimulating hormone also contributed to increased SBP independently from NOSTOX. Although there were no significant changes in SBP/DBP in mood disorders, the associations between NOSTOX and blood pressure were significant in patients with mood disorders but not in healthy controls.

CONCLUSIONS

Activated O&NS pathways including increased lipid peroxidation and protein oxidation, which indicates hypochlorous stress, are the most important predictors of an increased BP, especially in patients with mood disorders.

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.

Pulmonary Hypertension and Hypocholesterolemia Secondary to Thyrotoxicosis

Background

Thyroid disorders commonly affect the cardiovascular system. Thyrotoxicosis leading to pulmonary hypertension has been increasingly reported during recent years. Thyroid dysfunction affects the lipid metabolism, and thyrotoxicosis can be associated with low lipid levels. Thyrotoxicosis presenting with right ventricular dysfunction is rare, and only few cases had been reported. Case Presentation. A 53-year-old woman presented with progressive shortness of breath and swelling of body for four months. Examination showed generalized oedema and a systolic murmur over the left sternal border. Transthoracic echocardiography confirmed pulmonary hypertension with tricuspid regurgitation. Investigations revealed thyrotoxicosis and very low cholesterol levels. Diagnosis of Graves' disease was confirmed with detection of thyrotropin receptor antibodies. Pulmonary pressure was normalized six months after antithyroid therapy.

Conclusion

Thyrotoxicosis is a recognized cause of reversible pulmonary hypertension and acquired hypocholesterolemia. However, most clinicians are not aware of these associations. This case illustrates the importance of assessing thyroid function in patients presenting with pulmonary hypertension.

Prospective role of thyroid disorders in monitoring COVID-19 pandemic

COVID-19 pandemic has affected more than 200 countries and 1.3 million individuals have deceased within eleven months. Intense research on COVID-19 occurrence and prevalence enable us to understand that comorbidities play a crucial role in spread and severity of SARS-CoV-2 infection. Chronic kidney disease, diabetes, respiratory diseases and hypertension are among the various morbidities that are prevalent in symptomatic COVID-19 patients. However, the effect of altered thyroid-driven disorders cannot be ignored. Since thyroid hormone critically coordinate and regulate the major metabolism and biochemical pathways, this review is on the potential role of prevailing thyroid disorders in SARS-CoV-2 infection. Direct link of thyroid hormone with several disorders such as diabetes, vitamin D deficiency, obesity, kidney and liver disorders etc. suggests that the prevailing thyroid conditions may affect SARS-CoV-2 infection. Further, we discuss the oxidative stress-induced aging is associated with the degree of SARS-CoV-2 infection. Importantly, ACE2 protein which facilitates the host-cell entry of SARS-CoV-2 using the spike protein, are highly expressed in individuals with abnormal level of thyroid hormone. Altogether, we report that the malfunction of thyroid hormone synthesis may aggravate SARS-CoV-2 infection and thus monitoring the thyroid hormone may help in understanding the pathogenesis of COVID-19.

Diagnosis and Management of Endocrine Hypertension in Children and Adolescents

Hypertension in childhood and adolescence has increased in prevalence. Interest in the disease was raised after the 2017 clinical practice guidelines of the American Academy of Paediatrics on the definition and classification of paediatric hypertension. Among the secondary causes of paediatric hypertension, endocrine causes are relatively rare but important due to their unique treatment options. Excess of catecholamine, glucocorticoids and mineralocorticoids, congenital adrenal hyperplasia, hyperaldosteronism, hyperthyroidism and other rare syndromes with specific genetic defects are endocrine disorders leading to paediatric and adolescent hypertension. Adipose tissue is currently considered the major endocrine gland. Obesity-related hypertension constitutes a distinct clinical entity leading to an endocrine disorder. The dramatic increase in the rates of obesity during childhood has resulted in a rise in obesity-related hypertension among children, leading to increased cardiovascular risk and associated increased morbidity and mortality. This review presents an overview of pathophysiology and diagnosis of hypertension resulting from hormonal excess, as well as obesity-related hypertension during childhood and adolescence, with a special focus on management.

Associations between thyroid-stimulating hormone and hypertension according to thyroid cyst status in the general population: a cross-sectional study

Background

The absence of thyroid cysts may indicate latent thyroid damage, as demonstrated in our previous study. However, the association between the absence of thyroid cysts and latent functional damage of the thyroid is unknown. At low thyroid hormone productivity, which may be associated with latent functional damage of the thyroid, the association between thyroid-stimulating hormone (TSH) and hypertension might be enhanced. Therefore, we evaluated the association between TSH level and hypertension stratified by thyroid cyst status.

Methods

We conducted a cross-sectional study of 1724 euthyroid Japanese individuals aged 40–74 years who participated in an annual health checkup in 2014.

Results

In the study population, 564 and 686 participants had thyroid cysts and hypertension, respectively. A significant positive association was observed between TSH and hypertension in subjects without a thyroid cyst but not in subjects with thyroid cysts. There was a significant positive association between hypertension and TSH in subjects without a thyroid cyst (odds ratio [OR] 1.27; 95% confidence intervals [CI] 1.01, 1.61) but not in subjects with thyroid cysts (OR 0.79; CI 0.57, 1.09) in the model fully adjusted for known confounding factors. The correlation between the TSH and free triiodothyronine (fee T3) levels (simple correlation coefficient [r] = − 0.13, p < 0.01) was stronger in the subjects without thyroid cysts than in those with thyroid cysts (r = − 0.03, p = 0.525).

Conclusions

TSH is positively associated with hypertension only in individuals without thyroid cysts. The correlation between the TSH and free T3 levels was stronger in the subjects without thyroid cysts than in those with thyroid cysts. Therefore, the absence of thyroid cysts could be related to the association between TSH level and hypertension, possibly by indicating that the subjects without thyroid cysts had limited thyroid hormone reserves. Therefore, the absence of thyroid cysts could indicate the latent functional damage of the thyroid.

Endocrine Causes of Hypertension

PURPOSE OF REVIEW

To discuss selected endocrine causes of hypertension and to provide practical clinical recommendations regarding the evaluation and treatment of these disorders.

RECENT FINDINGS

More than 15 endocrine disorders with varying rates of prevalence can cause hypertension. For example, primary aldosteronism may exist in up to 20% of patients with resistant hypertension. Recognition of these important secondary causes of hypertension is essential to provide contemporary targeted therapies in order to improve long-term disease outcomes. Clinicians must have a broad understanding of the prevalence, clinical presentation, and current diagnostic modalities for endocrine causes of hypertension to facilitate prompt referral, identification, and optimal management of these disorders. Endocrine causes of hypertension are multifactorial and, in some cases, widely prevalent. It is important for clinicians considering secondary causes of hypertension to be knowledgeable about the underlying pathophysiology of these disorders and to understand when additional evaluation and treatment may be needed.

Hypertension and Hyperthyroidism: Association and Pathogenesis

Hypertension can cause significant morbidity and reduced life expectancy. Most patients with hypertension have primary hypertension; however, 10 to 15% of patients have secondary hypertension. Endocrine disorders explain approximately 10% of hypertension in all patients, and thyroid disorders account for approximately 1% of cases with hypertension. Hyperthyroidism can cause increased cardiac output, increased systolic blood pressures, and increased levels of renin, angiotensin, and aldosterone. Treatment of hyperthyroidism can cure hypertension in some patients. Consequently, identification of patients with secondary hypertension potentially has important benefits, and understanding secondary hypertension provides a framework for investigating the pathophysiology of hypertension. Clinicians should consider the possibility of hyperthyroidism in patients with hypertension, even in those of more advanced age.

PhenomeXcan: Mapping the genome to the phenome through the transcriptome

Large-scale genomic and transcriptomic initiatives offer unprecedented insight into complex traits, but clinical translation remains limited by variant-level associations without biological context and lack of analytic resources. Our resource, PhenomeXcan, synthesizes 8.87 million variants from genome-wide association study summary statistics on 4091 traits with transcriptomic data from 49 tissues in Genotype-Tissue Expression v8 into a gene-based, queryable platform including 22,515 genes. We developed a novel Bayesian colocalization method, fast enrichment estimation aided colocalization analysis (fastENLOC), to prioritize likely causal gene-trait associations. We successfully replicate associations from the phenome-wide association studies (PheWAS) catalog Online Mendelian Inheritance in Man, and an evidence-based curated gene list. Using PhenomeXcan results, we provide examples of novel and underreported genome-to-phenome associations, complex gene-trait clusters, shared causal genes between common and rare diseases via further integration of PhenomeXcan with ClinVar, and potential therapeutic targets. PhenomeXcan (phenomexcan.org) provides broad, user-friendly access to complex data for translational researchers.

The role of thyroid hormone in metabolism and metabolic syndrome

Metabolic syndrome (MetS) and thyroid dysfunction are common in clinical practice. The objectives of this review are to discuss some proposed mechanisms by which thyroid dysfunctions may lead to MetS, to describe the bidirectional relationship between thyroid hormones (THs) and adiposity and finally, to resume a list of recent studies in humans that evaluated possible associations between thyroid hormone status and MetS or its clinical components. Not solely THs, but also its metabolites regulate metabolic rate, influencing adiposity. The mechanisms enrolled are related to its direct effect on adenosine triphosphate (ATP) utilization, uncoupling synthesis of ATP, mitochondrial biogenesis, and its inotropic and chronotropic effects. THs also act controlling core body temperature, appetite, and sympathetic activity. In a bidirectional way, thyroid function is affected by adiposity. Leptin is one of the hallmarks, but the pro-inflammatory cytokines and also insulin resistance impact thyroid function and perhaps its structure. MetS development and weight gain have been positively associated with thyroid-stimulating hormone (TSH) in several studies. Adverse glucose metabolism may be related to hyperthyroidism, but also to reduction of thyroid function or higher serum TSH, as do abnormal serum triglyceride levels. Hypo- and hyperthyroidism have been related to higher blood pressure (BP), that may be consequence of genomic or nongenomic action of THs on the vasculature and in the heart. In summary, the interaction between THs and components of MetS is complex and not fully understood. More longitudinal studies controlling each of all confounding variables that interact with endpoints or exposure factors are still necessary.

The influence of hypertensive environment on adipose tissue remodeling measured by fluorescence lifetime imaging in spontaneously hypertensive rats

There is a lack of information correlating low adiposity with hypertension experienced by Spontaneous Hypertensive Rats (SHR) or overweight and normotension in Wistar-Kyoto (WKY). We aimed to investigate this lipodystrophy phenomenon by measuring fluorescence lifetime (FLIM), optical redox ratio (ORR), serum levels of hypothalamic-pituitary-adrenal (HPA) and/or hypothalamic-pituitary-thyroid (HPT) hormones axes between Wistar, WKY and SHR before and after establishment of hypertension. Under high blood pressure, we evaluated serum adipokines. Brown adipose tissue was characterized as lower ORR and shorter FLIM compared to white adipose tissue. HPT axis showed a crucial role in the SHR adipose tissue configuration by attenuating whitening. The increased adiposity in WKY may act as a preventive agent for hypertension, since SHR, with low adiposity, establishes the disease. The hypertensive environment can highlight key adipokines that may result in new therapeutic approaches to the treatment of adiposity dysfunctions and hypertension.

Hyperthyroidism

Hyperthyroidism is a condition where the thyroid gland produces and secretes inappropriately high amounts of thyroid hormone which can lead to thyrotoxicosis. The prevalence of hyperthyroidism in the United States is approximately 1.2%. There are many different causes of hyperthyroidism, and the most common causes include Graves' disease (GD), toxic multinodular goiter and toxic adenoma. The diagnosis can be made based on clinical findings and confirmed with biochemical tests and imaging techniques including ultrasound and radioactive iodine uptake scans. This condition impacts many different systems of the body including the integument, musculoskeletal, immune, ophthalmic, reproductive, gastrointestinal and cardiovascular systems. It is important to recognize common cardiovascular manifestations such as hypertension and tachycardia and to treat these patients with beta blockers. Early treatment of cardiovascular manifestations along with treatment of the hyperthyroidism can prevent significant cardiovascular events. Management options for hyperthyroidism include anti-thyroid medications, radioactive iodine, and surgery. Anti-thyroid medications are often used temporarily to treat thyrotoxicosis in preparation for more definitive treatment with radioactive iodine or surgery, but in select cases, patients can remain on antithyroid medications long-term. Radioactive iodine is a successful treatment for hyperthyroidism but should not be used in GD with ophthalmic manifestations. Recent studies have shown an increased concern for the development of secondary cancers as a result of radioactive iodine treatment. In the small percentage of patients who are not successfully treated with radioactive iodine, they can undergo re-treatment or surgery. Surgery includes a total thyroidectomy for GD and toxic multinodular goiters and a thyroid lobectomy for toxic adenomas. Surgery should be considered for those who have a concurrent cancer, in pregnancy, for compressive symptoms and in GD with ophthalmic manifestations. Surgery is cost effective with a high-volume surgeon. Preoperatively, patients should be on anti-thyroid medications to establish a euthyroid state and on beta blockers for any cardiovascular manifestations. Thyroid storm is a rare but life-threatening condition that can occur with thyrotoxicosis that must be treated with a multidisciplinary approach and ultimately, definitive treatment of the hyperthyroidism.