The incidence of Graves’ orbitopathy (GO) is 16/100,000 in females and 2.9/100,000 in males as studied in Olmsted county. It can be calculated that the approximate prevalence is 0.25%. There is a ...gender bimodal distribution. Go usually occurs at the time of onset of the hyperthyroidism but may present up to a year before that time or as long as 5 years afterwards. Around 10–15% of patients have never been hyperthyroid and some are hypothyroid at GO presentation. Although the incidence of GO has probably been decreasing during the last 2 decades definite figures for this assertion are not available. Risk factors that may influence the incidence of GO include cigarette smoking and radioiodine treatment of hyperthyroidism. There are also complex genetic factors with multiple susceptibility alleles that contribute to the expression of the disease. The probability is that a reduction of the incidence of GO will be achieved by influencing the environmental factors.
Thyroid disease in pregnancy is a common clinical problem. Since the guidelines for the management of these disorders by the American Thyroid Association (ATA) were first published in 2011, ...significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid disease in women during pregnancy, preconception, and the postpartum period.
The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. The guideline task force had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.
The revised guidelines for the management of thyroid disease in pregnancy include recommendations regarding the interpretation of thyroid function tests in pregnancy, iodine nutrition, thyroid autoantibodies and pregnancy complications, thyroid considerations in infertile women, hypothyroidism in pregnancy, thyrotoxicosis in pregnancy, thyroid nodules and cancer in pregnant women, fetal and neonatal considerations, thyroid disease and lactation, screening for thyroid dysfunction in pregnancy, and directions for future research.
We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid disease in pregnant and postpartum women. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with these disorders.
Severe iodine deficiency during development results in maternal and fetal hypothyroidism and associated serious adverse health effects, including cretinism and growth retardation. Universal salt ...iodization is the first-line strategy for the elimination of severe iodine deficiency. Iodine supplementation is recommended for vulnerable groups in severely iodine-deficient regions where salt iodization is infeasible or insufficient. A recent clinical trial has informed best practices for iodine supplementation of severely iodine-deficient lactating mothers. Because of successful programs of universal salt iodization in formerly severely iodine-deficient regions around the world, public health concern has shifted toward mild to moderate iodine deficiency, which remains prevalent in many regions, especially among pregnant women. Observational studies have shown associations between both mild maternal iodine deficiency and mild maternal thyroid hypofunction and decreased child cognition. Iodine supplementation has been shown to improve indexes of maternal thyroid function, even in marginally iodine-deficient areas. However, no data are yet available from randomized controlled trials in regions of mild to moderate iodine insufficiency on the relation between maternal iodine supplementation and neurobehavioral development in the offspring; thus, the long-term benefits and safety of such supplementation are uncertain. Although it is clear that excessive iodine intake can cause alterations in thyroid function in susceptible individuals, safe upper limits for iodine intake in pregnancy have not been well defined. Well-designed, prospective, randomized controlled trials that examine the effects of iodine supplementation on maternal thyroid function and infant neurobehavioral development in mildly to moderately iodine-deficient pregnant women are urgently needed. In addition, clinical data on the effects of iodine excess in pregnant and lactating women are needed to inform current recommendations for safe upper limits on chronic iodine ingestion in general and on iodine supplementation in particular.
Thyroid function in pregnancy LAZARUS, John H
British medical bulletin,
03/2011, Letnik:
97, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Advances in understanding the physiology of thyroid function in normal pregnancy have highlighted the importance of the consequences of abnormal function on obstetric outcome and foetal well-being. ...Pubmed search was done using the terms thyroid and pregnancy. Areas of agreement are the following: gestational normative reference ranges for thyroid function tests are required for proper interpretation of any abnormalities. Measurement of thyroid-stimulating antibodies and antithyroid peroxidase antibodies is useful for diagnosis of thyroid disease in pregnancy. Treatment of Graves' hyperthyroidism should be done with propylthiouracil for first trimester only, then carbimazole or methimazole. Patients on levothyroxine require an increase in dosage during gestation. Areas of controversy are the following: total thyroxine (TT4) versus Free T4 (FT4) assays in pregnancy. Screening for thyroid function in early gestation: should it be routinely performed on everyone? What tests are appropriate? Growing points are the following: physiology of thyroxine delivery to the foetus. Establishment of gestational thyroid hormone reference ranges. Evaluation of strategies to screen thyroid function in early pregnancy. Areas timely for developing research are the following: placental thyroid hormone physiology, thyroid hormone therapy and screening thyroid function.
Objective:
The aim was to update the guidelines for the management of thyroid dysfunction during pregnancy and postpartum published previously in 2007. A summary of changes between the 2007 and 2012 ...version is identified in the Supplemental Data (published on The Endocrine Society's Journals Online web site at http://jcem.endojournals.org).
Evidence:
This evidence-based guideline was developed according to the U.S. Preventive Service Task Force, grading items level A, B, C, D, or I, on the basis of the strength of evidence and magnitude of net benefit (benefits minus harms) as well as the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence.
Consensus Process:
The guideline was developed through a series of e-mails, conference calls, and one face-to-face meeting. An initial draft was prepared by the Task Force, with the help of a medical writer, and reviewed and commented on by members of The Endocrine Society, Asia and Oceania Thyroid Association, and the Latin American Thyroid Society. A second draft was reviewed and approved by The Endocrine Society Council. At each stage of review, the Task Force received written comments and incorporated substantive changes.
Conclusions:
Practice guidelines are presented for diagnosis and treatment of patients with thyroid-related medical issues just before and during pregnancy and in the postpartum interval. These include evidence-based approaches to assessing the cause of the condition, treating it, and managing hypothyroidism, hyperthyroidism, gestational hyperthyroidism, thyroid autoimmunity, thyroid tumors, iodine nutrition, postpartum thyroiditis, and screening for thyroid disease. Indications and side effects of therapeutic agents used in treatment are also presented.
Evidence from the 1950s showed that Macedonia was iodine deficient. After the introduction of mandatory universal salt iodisation, the country saw a steady increase in iodine intake and decline in ...goitre prevalence, earning iodine-deficiency free status in 2003. Iodine status assessments in 2007 and 2016 showed adequate iodine intake among school age children (median urinary iodine concentration of 241 μg/L and 236 μg/L respectively). Macedonia participated in piloting the Iodine Global Network Programme Guidance on the use of iodised salt in industrially processed foods to better understand potential iodised salt intake from processed foods. One objective of implementation was to identify the need, opportunities, and required actions to strengthen the processed food component of the national salt iodisation policy. Data from the 2017 Household Consumption and Expenditure Survey (HCES) was used to determine household salt consumption, to identify widely-consumed, salt-containing industrially processed foods, and estimate typical daily intake of these foods. Their estimated contribution to iodine intake was estimated based on their salt content and the percentage of food industry salt that is iodised. Although the study has limitations, including a relatively small selection of foods, the results indicate potential iodine intake from iodised household salt and iodised salt in the selected foods of nearly 300% of the Estimated Average Requirement and over 220% of the Recommended Nutrient Intake for adults. This was approximately 50% of the tolerable safe Upper Level for iodine intake. The study confirmed high daily salt intake (11.2 grams from household salt only). Successful salt reduction would be expected to reduce iodine intake, however, modelling with 10% and 30% reduction implied this is unlikely to put any population group at risk of deficiency. It is recommended that implementation of salt iodisation and salt reduction policies are harmonized, alongside continued regular iodine status monitoring for different population groups.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Iodine (I) deficiency has been known for more than a century and is known to cause cretinism at the extreme end of the spectrum but also, importantly, impaired development and neurocognition in areas ...of mild deficiency. The WHO has indicated that median urinary iodine of 100–199 μg/l in a population is regarded as indicative of an adequate iodine intake. The understanding of the spectrum of iodine deficiency disorders led to the formation of The International Council for the Control of Iodine Deficiency Disorders which has promulgated the use of household iodized salt and the use of such salt in food processing and manufacture. Iodine deficiency is particularly important in pregnancy as the fetus relies on maternal thyroxine (T4) exclusively during the first 14 weeks and also throughout gestation. As this hormone is critical to brain and nervous system maturation, low maternal T4 results in low child intelligence quotient. The recommendation for I intake in pregnancy is 250 μg/day to prevent fetal and child brain function impairment. During the past 25 years, the number of countries with I deficiency has reduced to 32; these still include many European developed countries. Sustainability of adequate iodine status must be achieved by continuous monitoring and where this has not been performed I deficiency has often recurred. More randomized controlled trials of iodine supplementation in pregnancy are required in mild iodine-deficient areas to inform public health strategy and subsequent government action on suitable provision of iodine to the population at risk.
Summary Background Iodine deficiency is the most common cause of preventable mental impairment worldwide. It is defined by WHO as mild if the population median urinary iodine excretion is 50–99 μg/L, ...moderate if 20–49 μg/L, and severe if less than 20 μg/L. No contemporary data are available for the UK, which has no programme of food or salt iodination. We aimed to assess the current iodine status of the UK population. Methods In this cross-sectional survey, we systematically assessed iodine status in schoolgirls aged 14–15 years attending secondary school in nine UK centres. Urinary iodine concentrations and tap water iodine concentrations were measured in June–July, 2009, and November–December, 2009. Ethnic origin, postcode, and a validated diet questionnaire assessing sources of iodine were recorded. Findings 810 participants provided 737 urine samples. Data for dietary habits and iodine status were available for 664 participants. Median urinary iodine excretion was 80·1 μg/L (IQR 56·9–109·0). Urinary iodine measurements indicative of mild iodine deficiency were present in 51% (n=379) of participants, moderate deficiency in 16% (n=120), and severe deficiency in 1% (n=8). Prevalence of iodine deficiency was highest in Belfast (85%, n=135). Tap water iodine concentrations were low or undetectable and were not positively associated with urinary iodine concentrations. Multivariable general linear model analysis confirmed independent associations between low urinary iodine excretion and sampling in summer (p<0·0001), UK geographical location (p<0·0001), low intake of milk (p=0·03), and high intake of eggs (p=0·02). Interpretation Our findings suggest that the UK is iodine deficient. Since developing fetuses are the most susceptible to adverse effects of iodine deficiency and even mild perturbations of maternal and fetal thyroid function have an effect on neurodevelopment, these findings are of potential major public health importance. This study has drawn attention to an urgent need for a comprehensive investigation of UK iodine status and implementation of evidence-based recommendations for iodine supplementation. Funding Clinical Endocrinology Trust.
PDF
