-
Lancet (London, England) Sep 2017Hypothyroidism is a common condition of thyroid hormone deficiency, which is readily diagnosed and managed but potentially fatal in severe cases if untreated. The... (Review)
Review
Hypothyroidism is a common condition of thyroid hormone deficiency, which is readily diagnosed and managed but potentially fatal in severe cases if untreated. The definition of hypothyroidism is based on statistical reference ranges of the relevant biochemical parameters and is increasingly a matter of debate. Clinical manifestations of hypothyroidism range from life threatening to no signs or symptoms. The most common symptoms in adults are fatigue, lethargy, cold intolerance, weight gain, constipation, change in voice, and dry skin, but clinical presentation can differ with age and sex, among other factors. The standard treatment is thyroid hormone replacement therapy with levothyroxine. However, a substantial proportion of patients who reach biochemical treatment targets have persistent complaints. In this Seminar, we discuss the epidemiology, causes, and symptoms of hypothyroidism; summarise evidence on diagnosis, long-term risk, treatment, and management; and highlight future directions for research.
Topics: Disease Management; Hormone Replacement Therapy; Hypothyroidism; Thyroxine
PubMed: 28336049
DOI: 10.1016/S0140-6736(17)30703-1 -
Methodist DeBakey Cardiovascular Journal 2017Hypothyroidism is a commonly encountered clinical condition with variable prevalence. It has profound effects on cardiac function that can impact cardiac contractility,... (Review)
Review
Hypothyroidism is a commonly encountered clinical condition with variable prevalence. It has profound effects on cardiac function that can impact cardiac contractility, vascular resistance, blood pressure, and heart rhythm. With this review, we aim to describe the effects of hypothyroidism and subclinical hypothyroidism on the heart. Additionally, we attempt to briefly describe how hypothyroid treatment affects cardiovascular parameters.
Topics: Heart; Heart Diseases; Humans; Hypothyroidism; Prognosis; Risk Assessment; Risk Factors; Thyroid Gland
PubMed: 28740582
DOI: 10.14797/mdcj-13-2-55 -
Thyroid : Official Journal of the... Mar 2021An ENDO-European Reference Network (ERN) initiative was launched that was endorsed by the European Society for Pediatric Endocrinology and the European Society for... (Review)
Review
Congenital Hypothyroidism: A 2020-2021 Consensus Guidelines Update-An ENDO-European Reference Network Initiative Endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology.
An ENDO-European Reference Network (ERN) initiative was launched that was endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology with 22 participants from the ENDO-ERN and the two societies. The aim was to update the practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). A systematic literature search was conducted to identify key articles on neonatal screening, diagnosis, and management of primary and central CH. The evidence-based guidelines were graded with the Grading of Recommendations, Assessment, Development and Evaluation system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. The recommendations include the various neonatal screening approaches for CH as well as the etiology (also genetics), diagnostics, treatment, and prognosis of both primary and central CH. When CH is diagnosed, the expert panel recommends the immediate start of correctly dosed levothyroxine treatment and frequent follow-up including laboratory testing to keep thyroid hormone levels in their target ranges, timely assessment of the need to continue treatment, attention for neurodevelopment and neurosensory functions, and, if necessary, consulting other health professionals, and education of the child and family about CH. Harmonization of diagnostics, treatment, and follow-up will optimize patient outcomes. Lastly, all individuals with CH are entitled to a well-planned transition of care from pediatrics to adult medicine. This consensus guidelines update should be used to further optimize detection, diagnosis, treatment, and follow-up of children with all forms of CH in the light of the most recent evidence. It should be helpful in convincing health authorities of the benefits of neonatal screening for CH. Further epidemiological and experimental studies are needed to understand the increased incidence of this condition.
Topics: Benchmarking; Congenital Hypothyroidism; Consensus; Endocrinology; Evidence-Based Medicine; Humans; Infant, Newborn; Neonatal Screening; Predictive Value of Tests; Prognosis; Risk Factors; Transition to Adult Care
PubMed: 33272083
DOI: 10.1089/thy.2020.0333 -
Australian Journal of General Practice 2021Hypothyroidism and hyperthyroidism are commonly encountered in clinical practice. General practitioners have a central role in the long-term management of these... (Review)
Review
BACKGROUND
Hypothyroidism and hyperthyroidism are commonly encountered in clinical practice. General practitioners have a central role in the long-term management of these conditions.
OBJECTIVE
The aim of this review is to provide an overview of the causes of thyroid function disorders and guidance on management.
DISCUSSION
Optimal management of hypothyroidism relies on an understanding of the potential risks and benefits of therapy versus observation. If levothyroxine (LT4) replacement is commenced in a person with subclinical hypothyroidism on the basis of the presence of possibly relevant hypothyroid symptoms, consideration should be given to ceasing LT4 if no symptomatic benefit is observed. Thyroid stimulating hormone levels below the reference range are associated with atrial fibrillation and osteoporosis, and should be avoided. Treatment modalities for hyperthyroidism include antithyroid medications, radioactive iodine therapy and thyroidectomy. Each is satisfactory, but none is ideal. A patient-centred choice of treatment modality should be individualised, taking into consideration the underlying pathology, age, sex, patient preference and availability of expert thyroid surgical care. Long-term management of patients with hyperthyroidism requires careful consideration of the likely outcomes of treatment including the risk of hypothyroidism.
Topics: Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Thyroid Neoplasms; Thyroxine
PubMed: 33543160
DOI: 10.31128/AJGP-09-20-5653 -
Polish Archives of Internal Medicine Aug 2019Myxedema coma and thyroid storm are among the most common endocrine emergencies presenting to general hospitals. Myxedema coma represents the most extreme,... (Review)
Review
Myxedema coma and thyroid storm are among the most common endocrine emergencies presenting to general hospitals. Myxedema coma represents the most extreme, life‑threatening expression of severe hypothyroidism, with patients showing deteriorating mental status, hypothermia, and multiple organ system abnormalities. It typically appears in patients with preexisting hypothyroidism via a common pathway of respiratory decompensation with carbon dioxide narcosis leading to coma. Without early and appropriate therapy, the outcome is often fatal. The diagnosis is based on history and physical findings at presentation and not on any objective thyroid laboratory test. Clinically based scoring systems have been proposed to aid in the diagnosis. While it is a relatively rare syndrome, the typical patient is an elderly woman (thyroid hypofunction being much more common in women) who may or may not have a history of previously diagnosed or treated thyroid dysfunction. Thyrotoxic storm or thyroid crisis is also a rare condition, established on the basis of a clinical diagnosis. The diagnosis is based on the presence of severe hyperthyroidism accompanied by elements of systemic decompensation. Considering that mortality is high without aggressive treatment, therapy must be initiated as early as possible in a critical care setting. The diagnosis cannot be established based on laboratory tests alone, but several scoring systems are available. The usual clinical signs and symptoms of hyperthyroidism are present along with more exaggerated clinical manifestations affecting the cardiovascular, gastrointestinal, and central nervous systems. A multipronged approach has been recommended and has been associated with improved outcomes.
Topics: Critical Care; Emergencies; Humans; Myxedema; Thyroid Crisis; Thyroid Function Tests
PubMed: 31237256
DOI: 10.20452/pamw.14876 -
Advances in Therapy Sep 2019Hypothyroidism affects up to 5% of the general population, with a further estimated 5% being undiagnosed. Over 99% of affected patients suffer from primary... (Review)
Review
Hypothyroidism affects up to 5% of the general population, with a further estimated 5% being undiagnosed. Over 99% of affected patients suffer from primary hypothyroidism. Worldwide, environmental iodine deficiency is the most common cause of all thyroid disorders, including hypothyroidism, but in areas of iodine sufficiency, Hashimoto's disease (chronic autoimmune thyroiditis) is the most common cause of thyroid failure. Hypothyroidism is diagnosed biochemically, being overt primary hypothyroidism defined as serum thyroid-stimulating hormone (TSH) concentrations above and thyroxine concentrations below the normal reference range. Symptoms of hypothyroidism are non-specific and include mild to moderate weight gain, fatigue, poor concentration, depression, and menstrual irregularities, while the consequences of untreated or under-treated hypothyroidism include cardiovascular disease and increased mortality. Levothyroxine has long been the main tool for treating hypothyroidism and is one of the world's most widely prescribed medicines. In adults with overt hypothyroidism, levothyroxine is usually prescribed at a starting dose of 1.6 µg/kg/day, which is then titrated to achieve optimal TSH levels (0.4-4.0 mIU/L), according to the therapeutic target. We here summarise the history of levothyroxine and discuss future issues regarding the optimal treatment of hypothyroidism. Because nearly one-third of patients with treated hypothyroidism still exhibit symptoms, it is important that levothyroxine is used more appropriately to achieve maximum benefit for patients. In order to ensure this, further research should include more accurate assessments of the true prevalence of hypothyroidism in the community, optimisation of the levothyroxine substitution dose, proper duration of treatment, and identification of patients who may benefit from combination therapy with levothyroxine plus levotriiodothyronine.Funding: Merck.Plain Language Summary: Plain language summary available for this article.
Topics: Adult; Cardiovascular Diseases; Depression; Female; Humans; Hypothyroidism; Thyrotropin; Thyroxine
PubMed: 31485975
DOI: 10.1007/s12325-019-01080-8 -
Frontiers in Endocrinology 2020Subclinical hypothyroidism is a biochemical condition defined by elevated serum thyroid-stimulating hormone levels in the setting of normal levels of the peripheral... (Review)
Review
Subclinical hypothyroidism is a biochemical condition defined by elevated serum thyroid-stimulating hormone levels in the setting of normal levels of the peripheral thyroid hormones, thyroxine and triiodothyronine. Thyroid hormones act on the heart through various mechanisms and subclinical hypothyroidism has been associated with risk factors for cardiovascular disease, such as hypertension and dyslipidemia. In addition, evidence from multiple studies supports an association between subclinical hypothyroidism and cardiovascular disease. However, the use of levothyroxine in subclinical hypothyroidism to reduce cardiovascular disease risk is not clearly beneficial. Treatment with levothyroxine may only provide benefit in certain subgroups, such as patients who are younger or at higher risk of cardiovascular disease. At present, most of the international societal guidelines advise that treatment decisions should be individualized based on patient age, degree of serum thyroid-stimulating hormone (TSH) elevation, symptoms, cardiovascular disease (CVD) risk, and other co-morbidities. Further study in this area is recommended.
Topics: Animals; Cardiovascular Diseases; Humans; Hypothyroidism; Thyroxine
PubMed: 33193104
DOI: 10.3389/fendo.2020.591588 -
Frontiers in Endocrinology 2021Central congenital hypothyroidism (CH) is defined as thyroid hormone (TH) deficiency at birth due to insufficient stimulation by the pituitary of the thyroid gland. The... (Review)
Review
Central congenital hypothyroidism (CH) is defined as thyroid hormone (TH) deficiency at birth due to insufficient stimulation by the pituitary of the thyroid gland. The incidence of central CH is currently estimated at around 1:13,000. Central CH may occur in isolation, but in the majority of cases (60%) it is part of combined pituitary hormone deficiencies (CPHD). In recent years several novel genetic causes of isolated central CH have been discovered (, , ), and up to 90% of isolated central CH cases can be genetically explained. For CPHD the etiology usually remains unknown, although pituitary stalk interruption syndrome does seem to be the most common anatomic pituitary malformation associated with CPHD. Recent studies have shown that central CH is a more severe condition than previously thought, and that early detection and treatment leads to good neurodevelopmental outcome. However, in the neonatal period the clinical diagnosis is often missed despite hospital admission because of feeding problems, hypoglycemia and prolonged jaundice. This review provides an update on the etiology and prognosis of central CH, and a practical approach to diagnosis and management of this intriguing condition.
Topics: Congenital Hypothyroidism; Hormone Replacement Therapy; Humans; Immunoglobulins; Infant, Newborn; Insulin Receptor Substrate Proteins; Membrane Proteins; Neonatal Screening; Prognosis; Thyrotropin, beta Subunit; Thyroxine; Transducin
PubMed: 34566885
DOI: 10.3389/fendo.2021.686317 -
Endocrine Reviews Jun 2019Thyroid dysfunction and diabetes mellitus are closely linked. Several studies have documented the increased prevalence of thyroid disorders in patients with diabetes... (Review)
Review
Thyroid dysfunction and diabetes mellitus are closely linked. Several studies have documented the increased prevalence of thyroid disorders in patients with diabetes mellitus and vice versa. This review critically discusses the different underlying mechanisms linking type 1 and 2 diabetes and thyroid dysfunction to demonstrate that the association of these two common disorders is unlikely a simple coincidence. We assess the current state of knowledge on the central and peripheral control of thyroid hormone on food intake and glucose and lipid metabolism in target tissues (such as liver, white and brown adipose tissue, pancreatic β cells, and skeletal muscle) to explain the mechanism linking overt and subclinical hypothyroidism to type 2 diabetes and metabolic syndrome. We also elucidate the common susceptibility genes and the pathogenetic mechanisms contributing to the autoimmune mechanism involved in the onset of type 1 diabetes mellitus and autoimmune thyroid disorders. An untreated thyroid dysfunction can impair the metabolic control of diabetic patients, and this association can have important repercussions on the outcome of both of these disorders. Therefore, we offer recommendations for the diagnosis, management, and screening of thyroid disorders in patients with diabetes mellitus, including the treatment of diabetic patients planning a pregnancy. We also discuss the major causes of failure to achieve an optimal management of thyroid dysfunction in diabetic patients and provide recommendations for assessing and treating these disorders during therapy with antidiabetic drugs. An algorithm for a correct approach of these disorders when linked is also provided.
Topics: Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Humans; Hypothyroidism; Thyroid Diseases
PubMed: 30649221
DOI: 10.1210/er.2018-00163 -
Acta Bio-medica : Atenei Parmensis Apr 2017Anaemia is a global public health problem affecting both developing and developed countries with major consequences for human health as well as social and economic... (Review)
Review
Anaemia is a global public health problem affecting both developing and developed countries with major consequences for human health as well as social and economic development. It occurs at all stages of the life cycle, but is more prevalent in pregnant women and young children. Iron deficiency anaemia (IDA) impairs thyroid metabolism in animals and human and may negatively affect growth and develpment of children. On the other hand both overt and subclinical hypothyroidism are associated with anemia and adding iron to thyroxine therapy improves both conditions compared to thyroxine therapy alone. In addition patients with chronic hemolytic anemia requiring repeated blood transfusion have high prevalence of hypothalamic-pituitary thyroid axis. Both primary hypothyroidism and central hypothyroidism occur in these patients with increasing prevalence with age, severity of the anemia and higher ferritin concentration denoting poor chelation. Proper blood transfusion and intensive chelation appears to prevent deterioration of thyroid function and in many cases can reverse thyroid pathology. Physicians treating these forms of anemia should be aware of thyroid disorders in these patients for early screening, prevention and proper management of any thyroid dysfunction.
Topics: Anemia, Iron-Deficiency; Anemia, Sickle Cell; Animals; Blood Transfusion; Chelation Therapy; Dietary Supplements; Humans; Hypothyroidism; Iron; beta-Thalassemia
PubMed: 28467346
DOI: 10.23750/abm.v88i1.6048