Cardiovascular risk in elderly hypothyroid patients

Human amnion-derived mesenchymal stem cells improve subclinical hypothyroidism by immunocompetence mediating apoptosis inhibition on thyroid cells in aged mice

Subclinical hypothyroidism (SCH) affects 10% of the global population, which is most prevalent in women and the elderly. However, it remains debatable whether the elderly with subclinical hypothyroidism needs thyroxine supplement. Human amnion-derived mesenchymal stem cells (hAMSCs) could play important roles in autoimmune diseases, suggesting that hAMSC be a candidate to regulate the thyroid function of female age-related subclinical hypothyroidism. Herein, we established the model of SCH in the aged female mice. This study was designed to investigate whether human amnion-derived mesenchymal stem cells (hAMSC) could effect on immune regulation, apoptosis inhibition of thyroid cells, thyroid function, blood lipid levels, and heart function. In addition, qualified hAMSCs were intravenously injected into aged female SCH mice via the tail vein on day 0 and day 10. The levels of thyroid hormone and blood lipids as well as cardiac function, serum immunological indexes, and apoptosis of thyroid cells were then analyzed on day 5, 10, 15, and 20; meanwhile, the quantity of Th1, Th2, Th17, and Treg immune cells in peripheral blood was evaluated before and on day 20 post-injection. Our study demonstrated that after hAMSC transplantation, the thyroid functions, blood lipid levels, and heart function indexes of age-related SCH (AR-SCH) mice were significantly improved. Consistent with this, Th1 and Treg cells increased significantly, while Th2 and Th17 cells decreased in peripheral blood. Apoptosis was also suppressed in the thyroid cells. In summary, hAMSC delivery can potentially be a safe and effective therapy for treating SCH in the elderly, improving related complications by immunomodulatory and apoptosis inhibition.

Association of longitudinal trends in thyroid function with incident carotid atherosclerosis in middle-aged and older euthyroid subjects: the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) cohort study

BACKGROUND

Previous studies have posited that an association exists between thyroid function and the heart and vasculature. It remains unclear, however, whether longitudinal trends in thyroid function contribute to the development of atherosclerosis. We conducted a cohort study to examine the association of longitudinal trends in thyroid function with incident carotid atherosclerosis (CA) in middle-aged and older euthyroid subjects.

METHODS

This cohort study's participants were recruited from the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study in Tianjin, China. Free triiodothyronine (FT3), thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured using chemiluminescence immunoassay. CA was assessed using carotid ultrasonography. Thyroid function and ultrasonography were assessed yearly during follow-up. Multivariable Cox proportional hazards regression models were used to assess the association between thyroid function and incident CA.

RESULTS

A total of 3,181 participants were enrolled in the cohort study. Within 7,762 person-years of follow-up, 944 participants developed CA, the incidence rate of CA was 122 per 1,000 person-years. The fully adjusted hazards ratios (95% confidence interval) of CA for per 1-unit increase in changes of FT3, FT4 and TSH were 1.34(1.22-1.47), 1.22(1.19-1.26) and 0.92 (0.77-1.09) (P < 0.0001, <0.0001 and = 0.32, respectively), respectively. Similar significant associations between mean levels of FT3 and FT4 and incident CA were observed. However, baseline thyroid function was not associated with incident CA.

CONCLUSIONS

These findings suggest that higher mean levels and higher values of changes in thyroid hormones were associated with a higher risk of incident CA in middle-aged and older euthyroid subjects.

Understanding Worry About Risks Associated With Thyroid Hormone Therapy: A National Survey of Endocrinologists, Family Physicians, and Geriatricians

OBJECTIVE

Thyroid hormone use is widespread, and prior studies have shown that over- and undertreatment with thyroid hormone are common. Our objective was to understand physician worry regarding risks associated with thyroid hormone therapy, specifically overtreatment or undertreatment.

METHODS

A nationwide survey was administered to physician members of the Endocrine Society, the American Academy of Family Practice, and the American Geriatrics Society. Participants were asked how often they were worried about various risks that may be associated with thyroid hormone over- or undertreatment, that is, cardiovascular complications, bone complications, and poor quality of life due to overtreatment or undertreatment with thyroid hormone. Multivariable regression analyses were conducted to determine physician characteristics associated with each worry.

RESULTS

The response rate was 63% (359 of 566); of those who responded, 128 (36%) were primary care physicians, 114 (32%) were endocrinologists, and 113 (32%) were geriatricians. Overall, 74 (21%) physicians reported that they frequently or always worried about cardiovascular complications, 74 (21%) about bone complications, 111 (31%) about the poor quality of life due to symptoms from undertreatment with thyroid hormone, and 87 (24%) about the poor quality of life due to symptoms from overtreatment with thyroid hormone. Endocrinologists were more likely to frequently or always worry about the patients' poor quality of life due to symptoms from overtreatment (odds ratio, 2.05; 95% confidence interval, 1.09-3.93) compared with primary care physicians.

CONCLUSION

Up to one third of the physicians frequently or always worried about risks resulting from the thyroid hormone overtreatment or undertreatment. More research is needed across specialties to understand physician perceptions of how thyroid hormone therapy impacts the patients' quality of life.

Subclinical Hypothyroidism in Geriatric Population and Its Association With Heart Failure

Heart failure (HF) is one of the most common causes of hospitalization in the geriatric age group, above 65 years. It is associated with high morbidity, mortality, and bad prognosis. Subclinical hypothyroidism (SCH) is a common condition present in this age group that significantly affects the cardiovascular system. Thus, this review attempts to elaborate on the association between subclinical hypothyroidism and heart failure in terms of their prevalence, pathogenesis, prognosis, and possible management in a geriatric age group. Among the various published literature on this topic on PubMed, PubMed Central, and Google Scholar, 36 relevant studies were selected to correlate this association. We found that both SCH and HF can be present concurrently in this age group. Especially in the geriatric population with thyroid-stimulating hormone (TSH) higher than ten mIu/L, there is an increased incidence of heart failure and a worse prognosis with preexisting heart failure. However, randomized controlled trials will be needed to explore further whether treatment is warranted or not in this age group.

[Safety and effectiveness of total hip arthroplasty in patients with hypothyroidism]

Objective

To evaluate the safety and effectiveness of total hip arthroplasty (THA) in patients with hypothyroidism.

Methods

Sixty-three patients with hypothyroidism (hypothyroidism group) and 63 euthyroid patients without history of thyroid disease (control group) who underwent primary unilateral THA between November 2009 and November 2018 were enrolled in this retrospective case control study. There was no significant difference between the two groups in gender, age, body mass index, hip side, reason for THA, American Society of Anesthesiology (ASA) classification, preoperative hemoglobin (Hb) level, and preoperative Harris score ( P>0.05). The perioperative thyroid stimulating hormone (TSH) and thyroxine (T ₄) levels, the hypothyroidism-related and other complications during hospitalization, the decrease in Hb, perioperative total blood loss, blood transfusion rate, length of hospital stays, and 90 days readmissions rate in the two groups were recorded and evaluated. The periprosthetic joint infection, aseptic loosening of the prosthesis, and hip Harris score during follow-up were recorded.

Results

The differences in the TSH and T ₄ of hypothyroidism group between pre- and 3 days post-operation were significant ( P>0.05) and no hypothyroidism-related complications occurred after THA. The decrease in Hb and perioperative total blood loss in the hypothyroidism group were significantly higher than those in the control group ( P<0.05), but there was no significant difference between the two groups in terms of transfusion rate, length of hospital stays, and 90 days readmission rates ( P>0.05). No significant difference in the rate of complications (liver dysfunction, heart failure, pulmonary infection, urinary infection, and wound complication) between the two groups was found ( P>0.05) except for the rate of intramuscular vein thrombosis which was significantly lower in the hypothyroidism group, and the rate of postoperative anemia which was significantly higher in the hypothyroidism group ( P<0.05). The two groups were followed up 1.0-9.9 years (mean, 6.5 years). At last follow-up, Harris score in both groups were significantly higher than those before operation ( P<0.05). An increase of 39.5±12.3 in hypothyroidism group and 41.3±9.3 in control group were recorded, but no significant difference was found between the two groups ( t=0.958, P=0.340). During the follow-up, 1 case of periprosthetic joint infection occurred in the hypothyroidism group, no loosening or revision was found in the control group.

Conclusion

With the serum TSH controlled within 0.5-3.0 mU/L and T ₄ at normal level preoperatively, as well as the application of multiple blood management, hypothyroid patients can safely go through THA perioperative period and effectively improve joint function, quality of life, and obtain good mid-term effectiveness.

Does well-controlled overt hypothyroidism increase the risk of total knee arthroplasty?

BACKGROUND

Overt hypothyroidism is widely accepted as a risk factor for adverse events following total knee arthroplasty (TKA). However, no prior study has preoperatively reversed hypothyroidism and reevaluated its risk. This retrospective study aimed at investigating whether well-controlled overt hypothyroidism would still increase the risk of TKA.

METHODS

Between November 2009 and November 2016, patients diagnosed with overt hypothyroidism but well controlled and underwent TKA were compared with euthyroid TKA patients. Data were extracted from our departmental database. Chi-squared test and t-tests were used for comparisons.

RESULTS

Hypothyroid patients had more blood loss and lower postoperative haemoglobin (Hb) and haematocrit level than the control group (all P < 0.05). Although the postoperative anaemia rate was lower in the control group (P = 0.01), there was no significant difference in the transfusion rate between the two groups (2.99% versus 7.46%, P = 0.10) or in the rates of other complications (P > 0.05). Interestingly, intramuscular venous thrombosis rate in hypothyroid patients was significantly lower than that in the control group (1.49% versus 9.70%, P = 0.00). Clinical outcome scores were comparable between the two groups throughout the course. And only one case of infection occurred in the hypothyroid patients.

CONCLUSION

Well-controlled overt hypothyroidism did not increase the risk of TKA, except for perioperative blood loss. Surgeons should be aware that even if hypothyroidism is reversed, the risk of more perioperative blood loss still exists and that, consequently, perioperative blood management is still essential in this population.

The influence of thyroid function on the coagulation system and its clinical consequences

Several studies indicate that low plasma levels of thyroid hormone shift the hemostatic system towards a hypocoagulable and hyperfibrinolytic state, whereas high levels of thyroid hormone lead to more coagulation and less fibrinolysis. Low levels of thyroid hormone thereby seem to lead to an increased bleeding risk, whereas high levels, by contrast, increase the risk of venous thromboembolism. Hypothyroidism leads to a higher incidence of acquired von Willebrand's syndrome and with increasing levels of free thyroxine, levels of fibrinogen, factor VIII and von Willebrand factor, amongst others, increase gradually, to the extent that they may lead to symptomatic venous thromboembolism in patients with hyperthyroidism. Here, we discuss the literature on the effect of thyroid hormone on the hemostatic system and the associated risk of bleeding and venous thromboembolism. Patients with hypothyroidism are at increased risk of developing bleeding complications, which could be relevant in patients undergoing invasive procedures. Furthermore, physicians should be aware of the possibility of hyperthyroidism as an underlying risk factor for venous thromboembolism, especially in unexplained cases. Clinical studies are needed to further investigate the significance for general practice of these findings. Besides the effects of hyperthyroidism on venous thromboembolism, its effects on embolism secondary to atrial fibrillation are described.

High androgen levels protect against hypothyroidism

Introduction

Hypothyroidism is a common disorder, appearing mainly in women although less frequently found in women with polycystic ovary syndrome (PCOS). The objective was to test the hypothesis that hyperandrogenism might protect against hypothyroidism.

Material and methods

The data from three prospective follow‐up studies (up to 21 years) and one register study were compared: women with PCOS (Rotterdam criteria), n = 25, women with Turner syndrome, n = 217, a random population sample of women, n = 315, and men, n = 95 (the WHO MONICA study). Findings were to be verified or rejected in all females, n = 553 716, from the same region. The proportion of hypothyroidism was calculated and thyroid peroxidase antibodies (TPO) in serum were measured.

Results

Hypothyroidism at >50 years of age was found in 8% of women with PCOS, 4% in men (PCOS vs. men; ns), 43% of women with Turner syndrome, irrespective of karyotype (p < 0.001 vs. PCOS), and in 17% of postmenopausal women in the population (p < 0.01 vs. PCOS). Elevated TPO were similar in PCOS and women and men in the population but higher in Turner syndrome. Hypothyroidism increased with age in all groups except PCOS women and men. In the register study, hypothyroidism was less common in women with PCOS >25 years (5.5%) than in women without PCOS (6.8%) from the same region (p < 0.01).

Conclusions

Hypothyroidism was less frequently seen in women with PCOS and in men compared with women in the general population and among women with Turner syndrome. This was not explained by altered autoimmunity or the Y‐chromosome. Androgens seem to protect against hypothyroidism.

The effect of L-thyroxine replacement therapy on ischemia-modified albümin and malondialdehyde levels in patients with overt and subclinical hypothyroidism

BACKGROUND AND OBJECTIVES

The main objective of this study was to evaluate the levels of ischemia-modified albumin (IMA) and malondialdehyde (MDA) in patients with subclinical (SHypo) and overt hypothyroidism (OHypo), and to assess the effects of levothyroxine (LT₄) therapy on the oxidative stress (OS) parameters. We also investigated the relationships among serum thyroid hormones, lipid parameters, and IMA and MDA in these patients.

DESIGN AND METHODS

Thirty untreated patients with OHypo, 25 untreated patients with Shypo, and 30 age- and sex-matched healthy controls were prospectively included in the study. Biochemical and hormonal parameters including IMA and MDA were evaluated in all patients just before and one month after the maintenance of euthyroidism.

RESULTS

Compared with the control subjects, the levels of MDA and triglycerides (TG) significantly increased in patients with SHypo (p < 0.001 and p < 0.05, respectively), whereas high density lipoprotein cholesterol (HDL-C) levels significantly decreased (p = 0.01). Patients with OHypo showed significantly high MDA, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and TG levels (p = 0.001, p < 0.01, p = 0.01, and p < 0.01, respectively), and significantly low HDL-C levels compared with the controls (p < 0.05). MDA levels and lipid profile were not significantly different in the patients with OHypo when compared with the patients with SHypo. Serum IMA levels did not significantly change in patients with OHypo and SHypo compared with the controls. In the pre-treatment period, MDA levels were inversely correlated with HDL-C levels in patients with OHypo (r: -0.471, p = 0.009). Plasma MDA and LDL-C levels significantly decreased and HDL-C levels significantly increased in the groups of OHypo and SHypo after LT₄ treatment. Serum IMA levels did not significantly change with the therapy in all patient groups.

CONCLUSIONS

Increased MDA levels in both patient groups represent increased lipid peroxidation which might play an important role in the pathogenesis of the atherosclerosis seen in these patients. Increased OS in patients with SHypo and OHypo could be improved by LT₄ treatment. Also, MDA can be used as a reliable marker of OS and oxidative damage, while IMA is considered to be inappropriate.

Serum Thyroid Function, Mortality and Disability in Advanced Old Age: The Newcastle 85+ Study

CONTEXT

Perturbations in thyroid function are common in older individuals but their significance in the very old is not fully understood.

OBJECTIVE

This study sought to determine whether thyroid hormone status and variation of thyroid hormones within the reference range correlated with mortality and disability in a cohort of 85-year-olds.

DESIGN

A cohort of 85-year-old individuals were assessed in their own homes (community or institutional care) for health status and thyroid function, and followed for mortality and disability for up to 9 years.

SETTING AND PARTICIPANTS

Six hundred and forty-three 85-year-olds registered with participating general practices in Newcastle and North Tyneside, United Kingdom.

MAIN OUTCOMES

All-cause mortality, cardiovascular mortality, and disability according to thyroid disease status and baseline thyroid hormone parameters (serum TSH, FT₄, FT₃, and rT₃). Models were adjusted for age, sex, education, body mass index, smoking, and disease count.

RESULTS

After adjustment for age and sex, all-cause mortality was associated with baseline serum rT₃ and FT₃ (both P < .001), but not FT₄ or TSH. After additional adjustment for potential confounders, only rT₃ remained significantly associated with mortality (P = .001). Baseline serum TSH and rT₃ predicted future disability trajectories in men and women, respectively.

CONCLUSIONS

Our study is reassuring that individuals age 85 y with both subclinical hypothyroidism and subclinical hyperthyroidism do not have a significantly worse survival over 9 years than their euthyroid peers. However, thyroid function tests did predict disability, with higher serum TSH levels predicting better outcomes. These data strengthen the argument for routine use of age-specific thyroid function reference ranges.

Mean platelet volume is significantly associated with serum levels of thyroid-stimulating hormone in a cohort of older euthyroid subjects

PURPOSE

This retrospective and observational study aimed to establish whether any relationship exists between the values of serum thyroid-stimulating hormone (TSH) and those of the mean platelet volume (MPV) in a large cohort of older euthyroid Italian subjects.

MATERIALS AND METHOD

The study population was represented by a cohort of 1,050 ostensibly healthy and euthyroid patients aged 50 years and older, who were referred for screening of thyroid disorders over a 1-year period.

RESULTS

A significant association was found between MPV and TSH values in both simple (r = 0.12; p < 0.001) and multivariable regression analysis (beta coefficient, 0.07; p < 0.001) after adjustment for age, sex, free thyroxin values and platelet count. After stratification of the study population according to quartiles of serum TSH levels, a graded increase of MPV values was found from the first to the fourth quartile of TSH (p = 0.013). The odds ratio for an increased MPV value of the fourth versus the first quartile of TSH was 1.54 (95% CI, 1.08-2.20; p = 0.017).

CONCLUSIONS

The results of this investigation demonstrate that a significant, positive and independent association exists between MPV and serum TSH values in a large cohort of older euthyroid Italian subjects.

Cardiovascular Risk in Patients with Subclinical Hypothyroidism

Subclinical hypothyroidism (SCH) has been associated with increased cardiovascular mortality due to adverse effects mainly on lipids and blood pressure (BP). There is evidence that SCH, especially in patients with thyroid-stimulating hormone (TSH) >10mU/l, may increase cardiovascular risk. Some uncertainty exists regarding the association of SCH with BP; however, that the coexistence of SCH with BP and hypercholesterolaemia has a negative cardiovascular impact is beyond doubt. Insulin resistance, by modulating various risk factors including coagulation, may potentially increase cardiovascular risk. Periodic health examinations including screening has been advised in patients >35 years of age, while treatment with thyroxine should be tailored to each patient.

Sex-specific associations between thyrotropin and serum lipid profiles

BACKGROUND

Population-based studies investigating the sex-specific association between thyrotropin (TSH) levels and serum lipid concentrations are scarce. We examined the association between TSH and total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides in men and women from the general population. Furthermore, the association with TSH outside and within the reference range and lipid levels was studied.

METHODS

Individual data of 13,571 men and women without lipid medication of four population-based studies conducted in Western European adults were pooled for cross-sectional analyses. The association between TSH levels and lipid concentrations were analyzed by calculating sex-specific multivariable median regression models.

RESULTS

In the pooled population, serum TSH levels were significantly positively associated with triglyceride values in men and with total cholesterol, LDL cholesterol, and triglyceride values in women. In the pooled male population, low serum TSH levels (<3.0 mIU/L) were significantly associated with lower total cholesterol, while high serum TSH levels (≥ 3.0 mIU/L) were associated with higher triglyceride values. In the pooled female population, low serum TSH levels were significantly associated with lower total cholesterol, LDL cholesterol, and HDL cholesterol. High TSH levels were associated with higher total cholesterol and LDL cholesterol in the pooled female population. In both sexes, serum TSH levels within the reference range (0.3-3.0 mIU/L) were significantly positively associated with triglyceride concentrations.

CONCLUSIONS

Increasing levels of TSH were associated with a less favorable lipid profile in both men and women from the general population. In both sexes, TSH levels within the reference range were significantly positively associated with triglyceride concentrations.

Thyroid dysfunction and cardiovascular risk factors in Bulgarian adults

The aim of this study was to determine the prevalence of thyroid dysfunction and its association with cardiovascular risk factors in an adult Bulgarian population. 2402 subjects were studied, 1347 female, 20–94y (median: 48.0y) and 1055 male, 20–91y (median: 45.5y). Body weight, height, waist circumference, arterial blood pressure, TSH, FT4 and lipids were measured. Known hypothyroidism was reported by 53 subjects (2.2%) and hyperthyroidism by 20 (0.8%). New hypothyroidism was found in 98 (4.1%), [subclinical (3.2%), overt (0.9%)]. New hyperthyroidism was found in 68 (2.9%), [subclinical (2.5%), overt (0.4%)]. New diagnosis of hypothyroidism and hyperthyroidism was entered in 84% and 87% in male subjects and 60% and 65% in the females respectively. Arterial hypertension was present in 40% of the women and in 47% of the men (p<0.001) and was more prevalent in hypothyroidism. Abdominal obesity and dyslipidemia were more prevalent in males and hypothyroid subjects. Arterial hypertension depended on age, gender and lipid status but not on thyroid function. CHD history depended on thyroid function and age. Conclusion: Most cases of thyroid dysfunction were undiagnosed, especially in the males. CV risk factors were more prevalent in the males with thyroid dysfunction a major determinant of CHD, but not hypertension.

Association of sympathovagal imbalance with cardiovascular risks in overt hypothyroidism

Background:

Cardiovascular morbidities have been reported in hypothyroidism.

Aims:

The objective of this study is to investigate the link of sympathovagal imbalance (SVI) to cardiovascular risks (CVRs) and the plausible mechanisms of CVR in hypothyroidism.

Materials and Methods:

Age-matched 104 females (50 controls, 54 hypothyroids) were recruited and their body mass index (BMI), cardiovascular parameters, autonomic function tests by spectral analysis of heart rate variability (HRV), heart rate response to standing, deep breathing and blood pressure response to isometric handgrip were studied. Thyroid profile, lipid profile, immunological and inflammatory markers were estimated and their association with low-frequency to the high-frequency ratio (LF-HF) of HRV, the marker of SVI was assessed by multivariate regression.

Results:

Increased diastolic pressure, decreased HRV, increased LF-HF, dyslipidemia and increased high-sensitive C-reactive protein (hsCRP) were observed in hypothyroid patients and all these parameters had significant correlation with LF-HF. BMI had no significant association with LF-HF. Atherogenic index (β 1.144, P = 0.001) and hsCRP (b 0.578, P = 0.009) had independent contribution to LF-HF. LF-HF could significantly predict hypertension status (odds ratio 2.05, confidence interval 1.110-5.352, P = 0.008) in hypothyroid subjects.

Conclusions:

SVI due to sympathetic activation and vagal withdrawal occurs in hypothyroidism. Dyslipidemia and low-grade inflammation, but not obesity contribute to SVI and SVI contributes to cardiovascular risks.

Subclinical hypothyroidism in the elderly: to treat or not to treat?

Aging is associated with a host of alterations in thyroid gland structure and function. Some of these changes have favorable effects on longevity, whereas others are maladaptive and contribute to a decline in health and quality of life. An area of particular controversy is the diagnosis and management of subclinical hypothyroidism in the elderly. The clinical diagnosis of hypothyroidism in the elderly is difficult, because many signs and symptoms associated with hypothyroidism are commonly present in euthyroid elderly individuals. The biochemical profile of subclinical hypothyroidism includes normal serum levels of thyroid hormones with mildly elevated serum thyrotropin concentrations in the range of 4.5 to 10 mIU/L. In this article, the epidemiology of subclinical hypothyroidism in the elderly is reviewed, the potential advantages of mild hypothyroidism in people over the age of 75 years are discussed, and some guidelines for screening and management of this common thyroid dysfunction are suggested.

Approach to and treatment of thyroid disorders in the elderly

Thyroid gland dysfunction is prevalent in older adults and may be associated with significant morbidity if misdiagnosed and left untreated. Because of a decreased number of symptoms at presentation, an increased susceptibility to adverse events if not treated, and a greater likelihood of harm from treatment, the diagnosis and management of thyroid disorders in older adults can be challenging. This review focuses on the epidemiology, clinical presentation, risks and complications, and management of thyroid disorders in older adults, including hyperthyroidism, hypothyroidism, thyroid nodules, and thyroid cancer.

Endothelial dysfunction and subclinical hypothyroidism: a brief review

Subclinical hypothyroidism (SH) is characterized by normal serum free T4 and free T3 levels and increased serum TSH levels. The relationship between SH and cardiovascular diseases has been one of the most popular topics recently. There is still some controversy concerning the cardiovascular impact of SH and management protocols. The vast majority of the studies published so far, suggests that SH accelerates endothelial dysfunction through traditional effects on risk factors that promote atherosclerosis and nontraditional effects on vasculature. In particular, SH is associated with increased of LDL-cholesterol, diastolic blood pressure, and markers of chronic inflammation (C reactive protein) and simultaneously reduces the bioavailability of nitric oxide to blood vessels and increases the expression of angiotensin receptor. Furthermore, replacement therapy seems to improve all these aspects.

[Resistant hypertension despite nine different antihypertensive drugs?]

BACKGROUND

Treatment-resistant hypertension is a common problem in an outpatient setting and often results in hospital admission. Non-identified secondary hypertension, hypertensive nephrosclerosis and non-compliance are major reasons for treatment resistance.

CASE REPORT

A 75-year old woman was admitted to the emergency room because of a hypertensive crisis with alleged treatment-resistant hypertension and progressive headache. Two months ago, renal artery stenosis had been ruled out and a diagnosis of hypertensive cardiomyopathy was established. On admission, the patient had a blood pressure of 210/100 mmHg despite an antihypertensive treatment with nine different drugs. Further investigations ruled out secondary hypertension due to an endocrine cause but were consistent with hypertensive nephrosclerosis. With a supervised drug intake the blood pressure was rather normal to hypotensive, resulting in the need for significant reduction of the antihypertensive medication. The apparent discrepancies were discussed in detail with the patient who finally admitted a previous inconsistent intake of the antihypertensive drugs. Following thorough training and education on the purpose of continued antihypertensive therapy, the patient could be discharged with a normotensive blood pressure profile.

CONCLUSIONS

Therapy of treatment-resistant hypertension should always consider non-compliance and secondary hypertension as possible reason.

Hyperthyroidism and venous thrombosis: a casual or causal association? A systematic literature review

A kaleidoscope of coagulation disorders have been reported in patients with thyroid dysfunctions. Globally, these disorders involve both primary and secondary hemostasis and range from subclinical laboratory abnormalities to, more rarely, life-threatening hemorrhages or thrombotic events. While overt hypothyroidism appears to be associated with a bleeding tendency, hyperthyroidism emerged to have an increased risk of thrombotic events. In particular, a number of case reports have documented acute venous thrombosis complications in patients with overt hyperthyroidism, especially at cerebral sites. Nevertheless, further observational and intervention studies might be needed to provide a more definitive information on the clinical relevance of this association, along with the potential implication for prevention and treatment of coagulation-fibrinolytic abnormalities in patients with thyroid dysfunction.

[Markers of endothelial function in hypothyroidism]

The role of the endothelium in human disease has become the focus of scientific investigation and recently noninvasive and less expensive measures of endothelial function have become available. The endothelium modulates the vascular tonus and participates in inflammatory processes, platelet aggregation and thrombosis. Consequently, endothelial dysfunction has been implicated as an important event in the pathogenesis of atherosclerosis. Hypothyroidism is associated with an increased cardiovascular risk, and the assessment of endothelial function holds a great deal of promise as an assessment tool for the detection of preclinical cardiovascular alterations associated with thyroid dysfunction. Some recent studies have demonstrated a relationship between thyroid status and endothelial function, but large multicenter, placebo-controlled prospective trials are necessary to address this issue and the effect of levothyroxine replacement treatment in endothelial function. The objective of this work is to discuss the perspective picture in endothelium and thyroid function relationship.