Thyroid Hormone Preparations Research Articles

A 57-Year-Old Woman Present with Acute Delirium and Fever

<p>燒合併急性譫妄（Acute delirium），臨床上常被認為感染導致。本個案57歲女性，三天前因發燒、意識混亂與腹瀉，初步臆測診斷為細菌性腸炎造成譫妄，經糞便、血液細菌培養、腦部電腦斷層、腦脊髓液檢查、腦波與皮質酮（cortisol）檢驗均正常，抗生素治療下仍高燒不退、腹瀉、心搏過速，急劇意識昏迷併呼吸衰竭及全身抽搐。回顧此個案罹患甲狀腺機能亢進又擅自停藥，近期使用Xenetix碘顯影劑，當同時出現高燒、意識改變、腸胃肝膽障礙與心搏過速，按照甲狀腺風暴（Thyroid storm）診斷評分100分應高度懷疑甲狀腺風暴，盡快給予ß交感神經阻斷劑、降低甲狀腺激素合成、糖皮質類固醇、含碘製劑治療，經治療後個案意識與精神症狀獲得改善並順利出院。本篇教學著重如何快速鑑別診斷並牢記甲狀腺風暴評分項目與相關誘發因子，進而早期診斷與積極治療，可降低死亡率及多重器官衰竭，達到個案回歸日後自我照護能力。</p> <p> </p><p>Acute delirium is usually caused by infection, clinically. The case in this study is a 57-year-old woman with fever, confusion, and diarrhea for 3 days. The initial diagnosis was delirium caused by bacterial enteritis. Examinations of feces, blood bacteria culture, computed tomography scan, cerebrospinal flu-id, electroencephalography, and cortisol were all normal. However, high fever, diarrhea, tachycardia, acute unconsciousness with respiratory failure, and general convulsions persisted despite antibiotic treatment was applied. After recalling medical history the patient was suffered from hyperthyroidism and discontinued medication without permission. Furthermore, a Xenetix iodine contrast agent was re-cently administered while symptoms such as high fever, altered consciousness, gastrointestinal hepa-tobiliary disturbance, and tachycardia occurred simultaneously. Therefore, the possibility of a thyroid storm became apparent after applying the thyroid storm 100-point diagnosis scale evaluation. As such, ß sympathetic blockers, reduction of thyroid hormone synthesis, glucocorticoids, and preparations con-taining iodine were administered immediately. After treatments, the consciousness and mental symp-toms of the patient were improved and then successfully discharged. This case suggests that a rapid differential diagnosis by remembering the thyroid storm grading scale as well as relevant predisposing factors shell be considered in early diagnosis. Furthermore, proactive treatments could be utilized to reduce mortality rate and the possibility of multiple organ failure, thereby allowing patients to recover self-care ability in the future.</p> <p> </p>

갑상선기능저하증의 기능의학적 치료

Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormones to maintain normal physical activity. Common causes include autoimmune diseases such as Hashimoto's thyroiditis, surgical removal of the thyroid gland, and radiation therapy. It presents with a variety of clinical symptoms, including dry skin, puffiness, intolerance to cold, slowed thinking, and weight gain. However, there are patients who do not show sufficient symptom improvement with LT4 (levothyroxine) alone, the standard treatment for hypothyroidism. As our understanding of thyroid physiology advances, the reasons for discomfort during LT4 monotherapy are becoming clear, including problems with peripheral conversion of T4 (thyroxine) to T3 (triiodothyronine), genetic mutations in deiodinase and thyroid hormone transporter, and thyroid hormones resistance has been studied. In this article, we will look into the characteristics of each thyroid hormone preparation, conventional treatment on hypothyroidism, and thyroid physiology, and present the necessity of LT3 (liothyronine) and functional medicine approach and treatment when treating patients who do not improve with LT4 treatment alone.

Studying of Thyroid Dysfunction on Patients with Metabolic Syndrome

A retrospective study was conducted several studies aimed at knowing the relationship between the level of thyroid hormone and the metabolic syndrome and according to the results of the study, it is recommended to determine the level of tsh hormone in the pituitary gland in all patients as well as in all patients with risks of developing cardiovascular diseases: in patients who they suffer from obesity, dyslipidemia, arterial hypertension, hyperhomocysteinemia, and tobacco smoking., hereditary factor, diabetes mellitus type 2. No less important is the issue of treatment tactics in patients and in accordance with current recommendations, the appointment of thyroid hormone preparations is indicated for patients with an increase in the level of tsh more than 10 μm / l. The assignment of thyroxine to the boundary level of tsh is still a matter of debate. Most authors consider surgical myocardial revascularization, continuous statin therapy, and correction of subclinical hypothyroidism with small doses of thyroxine to normal tsh values as ideal. The most appropriate is the early detection of subclinical hypothyroidism in patients and correction of disorders identified with thyroid hormone preparations. The study showed that subclinical hypothyroidism is an additional independent risk factor.

Use of thyroid hormones in hypothyroid and euthyroid patients: a 2020 THESIS questionnaire survey of members of the Hellenic Endocrine Society.

To investigate current practices of specialists in the use of thyroid hormone preparations in Greece as part of an ongoing international survey, namely THESIS-Treatment of Hypothyroidism in Europe by Specialists: an International Survey. An electronic link leading to an anonymized questionnaire was sent to all (n = 837) members of the Hellenic Endocrine Society. In total, 501 respondents participated in the survey, though only part of the questionnaire was filled in by some participants. A total of 88.2% were endocrinologists and 57.9% worked in private practice. Levothyroxine (LT4) was the first-line choice (98.6%) for the treatment of hypothyroid patients. In total, 70.2% preferred LT4 soft-gel capsules for patients reporting intolerance to various foods. Soft-gel capsules were the preferred LT4 formulation for patients on generic LT4 and with unexplained poor biochemical control of hypothyroidism (66.3%) or inability to take LT4 fasted and separate from food/drink (68.3%). It was found that 48.4% would never use combined LT4 + LT3. However, 25% would use combination therapy for a short period in patients recovering from protracted hypothyroidism or in patients with normal serum TSH but persistent symptoms. Concerning euthyroid individuals, 31.9% considered treatment with thyroid hormones in infertile females with positive thyroid antibodies and 24.4% in patients with growing goiter. Selenium or iodine supplementation was used occasionally, mostly in patients with coexisting autoimmune thyroiditis. LT4 tablets are the treatment of choice for hypothyroidism in Greece. Several conditions may lead to various other practices, some of which deviate from current evidence-based guidelines and need more scrutiny.

Сравнение рекомендаций Американской тиреоидной ассоциации (АТА) и Американского колледжа ­акушеров-гинекологов (АКАГ) по заболеваниям щитовидной железы при беременности. Русский перевод

Thyroid dysfunction is relatively common in pregnancy. The American Thyroid Association (ATA) published its most recent guidelines regarding the management of thyroid disorders in pregnancy in 2017. The American College of Obstetricians and Gynecologists (ACOG) has recently published an updated practice bulletin for thyroid disease in pregnancy that supersedes its previous guidance published in 2015. A comparison of the similarities and differences between the clinical guidelines from the ATA and ACOG can serve to highlight areas of uncertainty where additional studies are needed and may also demonstrate areas where endocrinologists and obstetricians may elect differing approaches to clinical care. The ACOG and ATA guidelines recommend similar approaches to the interpretation of thyroid function testing during gestation and to the management of thyroid cancer, thyroid nodules, gestational thyrotoxicosis, and postpartum thyroiditis Both strongly recommend levothyroxine (L-T 4 ) treatment for overtly hypothyroid pregnant women, and both recommend against the use of T 3 -containing thyroid hormone preparations when treating hypothyroidism in pregnancy.

Comparison of ATA and Updated ACOG Guidelines for Thyroid Disease in Pregnancy. Russian translation

Thyroid dysfunction is relatively common in pregnancy. The American Thyroid Association (ATA) published its most recent guidelines regarding the management of thyroid disorders in pregnancy in 2017. The American College of Obstetricians and Gynecologists (ACOG) has recently published an updated practice bulletin for thyroid disease in pregnancy that supersedes its previous guidance published in 2015. A comparison of the similarities and differences between the clinical guidelines from the ATA and ACOG can serve to highlight areas of uncertainty where additional studies are needed and may also demonstrate areas where endocrinologists and obstetricians may elect differing approaches to clinical care. The ACOG and ATA guidelines recommend similar approaches to the interpretation of thyroid function testing during gestation and to the management of thyroid cancer, thyroid nodules, gestational thyrotoxicosis, and postpartum thyroiditis Both strongly recommend levothyroxine (L-T4) treatment for overtly hypothyroid pregnant women, and both recommend against the use of T3-containing thyroid hormone preparations when treating hypothyroidism in pregnancy.

Physician Perception and Patient Input Are Important Influences in the Treatment of Hypothyroidism

Physician Perception and Patient Input Are Important Influences in the Treatment of Hypothyroidism

Psychotherapy: Use in Persistent Anxiety and Depression.

Psychotherapy: Use in Persistent Anxiety and Depression.

Persistent hypothyroid symptoms in a patient with a normal thyroid stimulating hormone level.

A subset of patients being treated for hypothyroidism do not feel well while taking levothyroxine (LT4) replacement therapy, despite having a normal serum thyroid stimulating hormone level. Pursuing a relative triiodothyronine deficiency as a potential explanation for patient dissatisfaction, has led to trials of combination therapy with liothyronine (LT3), with largely negative outcomes. This review attempts to reconcile these diverse findings, consider potential explanations, and identify areas for future research. Patients being treated with LT4 often have lower triiodothyronine levels than patients with endogenous thyroid function. Linking patient dissatisfaction with low triiodothyronine levels has fueled multiple combination therapy trials that have generally not shown improvement in patient quality of life, mood, or cognitive performance. Some trials, however, suggest patient preference for combination therapy. There continues, moreover, to be anecdotal evidence that patients have fewer unresolved symptoms while taking combination therapy. The 14 trials completed to date have suffered from employing doses of LT3 that do not result in steady triiodothyronine levels, and having insufficient power to analyze results based on baseline dissatisfaction with therapy and patient genotype. Future trials that are able to incorporate such features may provide insight into what thyroid hormone preparations will most improve patient satisfaction with therapy.

Benign course after acute high dose levothyroxine intoxication in a 3-year-old boy.

.Acute ingestion of thyroid hormone preparations is a common intoxication, with 181 cases in children <12 yr in 2009 in the Netherlands, but generally has a mild course. However, some reports show that even low dosages may cause serious events such as seizures, thyroid storm and coma. We report a 3 yr old boy case with an acute intoxication with high dose levothyroxine (0.5 mg/kg). We describe the proper management of levothyroxine intoxication in children. A 3-year-old boy with no notable medical history ingested sixty tablets of levothyroxine 150 µg. His vital-signs were normal and the only symptom during admission was a tachycardia the following day. Laboratory data showed elevated T3, fT3 and fT4 levels; and decrease TSH levels. He was treated prophylactically and therapeutically with activated charcoal and propranolol. Despite very high levels, his clinical symptoms were relatively mild. After clinical follow-up for 3 d he was discharged. We propose that children with thyroid hormone intoxication with either a levothyroxine dose >0.1 g/kg, a short interval since ingestion, symptomatic presentation, and/or a fT4 >100 pmol/l should be monitored in the hospital during at least 48–72 h post-ingestion and on an outpatient basis for 14 d.

Thyroid Hormone Profile in Patients With Acute Coronary Syndrome.

Background:Thyroid hormone has the a major role in the cardiovascular system function and cardiac a As well as to maintain the cardiovascular homeostasis A slightly change ind thyroid status actually affects cardiovascular mortality hemodynamic. The background of this study was to define the prevalence of thyroid dysfunction in acute coronary syndrome (ACS).Objectives:The primary objective was to define the prevalence of thyroid dysfunction in acute coronary syndrome, including Non-ST Segment Elevation Myocardial Infarction (NSTEMI), ST-segment Elevation Myocardial Infarction (STEMI), and unstable angina groups. The secondary objective was to determine any associations of thyroids function tests with cardiac catheterization and mortality.Patients and Methods:In a prospective, observational, and cross section study, we enrolled 400 patients admitted at the coronary care unit of King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Venous blood samples were collected from patients for the evaluation of thyroid function (thyroids stimulating hormones, free triiodothyronine, and free thyroxin).Results:Excluding those taking thyroid hormone preparations, 76.7% of patients admitted with acute coronary heart disease (ST-segment elevation myocardial infarction and Non-ST segment elevation myocardial infarction), and unstable angina had euthyroidism. Thyroid dysfunction was reported in 23.3% of patients with coronary heart disease. Overall hypothyroidism prevalence was 7.8%, while subclinical hyperthyroidism in our study was 2.7%. Overt hyperthyroidism and subclinical hyperthyroidism was reported 2.0% and 0.5%, respectively. Euthyroid sick syndrome was noticed in 41 (10.2%) of critically ill patients. The mortality rate was 9.8%; all death patients had low triiodothyronine (T3) syndrome and were associated with statistically significant low free triiodothyronine (FT3) (P > 0.001).Conclusions:No significant variance was observed among patients underwent for cardiac catheterization, STEMI, NSTEMI, unstable angina, and atrial fibrillation with respect to FT4, FT3, and TSH levels during coronary care unit hospitalization based on their profile data.

Increases in Thyrotropin Within the Near-Normal Range Are Associated With Increased Triiodothyronine But Not Increased Thyroxine in the Pediatric Age Group

TSH has been shown in vitro to increase conversion of T4 to T3 and to preferentially increase thyroidal T3 secretion. Whether or not these effects are significant in vivo, other than in obesity, is unclear. To test whether the incremental relationships between free T4 (FT4), free T3 (FT3), and TSH are compatible with TSH enhancement of a preferential increase in serum FT3. A large database of pediatric and adolescent thyroid test results drawn in community clinics from children and adolescents without known thyroid disease was analyzed. RESULTS of FT3, FT4, and TSH were studied anonymously. They were crossed with electronic charts to exclude a history of positive thyroid autoantibodies and use of thyroid hormone preparations, antithyroid medication, or drugs known to affect thyroid function. All samples from patients appearing more than once in the database were removed. After exclusions, 3276 samples remained. FT4, FT3, and the FT3/FT4 ratios were correlated with TSH for the entire group, and the same parameters were segregated by TSH quartile. RESULTS were stratified for body mass index and studied separately in a normal-weight subgroup. Stepwise correlations of FT4, FT3, and FT3/FT4 ratios with TSH. There was a significant positive linear correlation of TSH with FT3 and FT3/FT4 ratios (R = 0.12; P < .0001 in both), but not with FT4. Within the near-euthyroid range, increasing TSH levels are associated with increasing FT3 levels, without an increase in FT4. This provides in vivo support for TSH enhancing preferentially T3 production and/or secretion.

Transfection with Sodium Iodine Symporter Gene (NIS) and Future Applications with Radioiodine Treatment

Human sodium iodine symporter gene (NIS) is the responsible factor for the effectiveness of radioiodine treatment in differentiated thyroid carcinoma. Previous studies in the literature have shown that loss of the NIS gene expression is the reason of ineffective treatment and dedifferentiation of the thyroid cancer. Definitely radioiodine treatment is the most effective cancer treatment method in the world. Probable applications of this treatment to the other types of tumors (like breast cancer, prostate cancer ect.) was the expected and wanted outcome of previous related studies which would be preferable to any kind of other treatments like chemo or radiation therapy. This has been achieved by transfection of cell lines with NIS gene by viruses. Additionally there have been these kinds of studies in the literature however none of these studies consist a stimulating factor like thyrotropin (TSH) for thyroid carcinoma. In radioiodine treatment the cornerstone of the treatment modality is the increased TSH levels in the plasma which can be achieved by withdrawal of thyroid hormone or recombinant TSH preparations. The TSH rich environment is the requirement of radioiodine treatment protocol. The future direction in radioiodine treatment would be the addition of a stimulating factor in the treatment environment. This stimulating factor might be TSH or other stimulants for various different cancer types like prostate specific antigen (PSA).

Treatment of Hypothyroidism: Possibilities on the Horizon

We would like to invite you to attend the upcoming spring symposium ‘‘Treatment of Hypothyroidism: Exploring the Possibilities.’’ We hope you will share the enthusiasm of the organizing committee regarding our exciting spectrum of topics and speakers. Although thyroid hormone therapy is by no means in its infancy, many aspects of its use are prescient and remain the subject of debate. We have progressed from the use of dried thyroid glands by ancient Chinese cultures (1), to the pioneering use of thyroid extracts given subcutaneously or orally in the 1890s (2), to the routine use of desiccated porcine or bovine thyroid preparations, and their subsequent replacement by synthetic levothyroxine during the mid-1970s (3). The expectation that use of levothyroxine would provide complete resolution of the constellation of symptoms that characterize hypothyroidism was a reasonable, but nevertheless overly optimistic, hope. Revolutionary though the availability of convenient, effective, and reliable synthetic thyroid hormone preparations has been, the specter of incomplete resolution of all symptoms associated with the hypothyroid condition has not left us. Individuals with hypothyroidism and normal thyrotropin (TSH) values may have less psychological well-being (4–6) and more fatigue (7) than individuals without thyroid disease. Some (8,9), but not all (10), studies suggest that serum triiodothyronine (T3) may be lower in levothyroxine-replaced patients than in the euthyroid population. Trials of combined therapy with both thyroxine (T4) and T3 in unselected populations have generally been disappointing (11–14). The seeming irreversibility of some ramifications of hypothyroidism may potentially be explained by the existence of genetic variations in deiodinases, TSH receptors, and thyroid hormone transporters (15–17). Our understanding of how such discoveries should influence our approach to the treatment of hypothyroidism will be advanced by adequately powered, prospective trials of the response of individuals harboring these genetic variations to specific therapies. Randomized, blinded, rigorously conducted, within-individual comparisons of therapy that can be subjected to metaanalysis may also advance our understanding (18). Through such means, the options of both synthetic and natural combination therapies will continue to be investigated. The possibility that some thyroid derivatives such as thyronamines have physiologic roles may need to be considered (19). Although there has been a hiatus since such products were reported in the literature (20), preparations of T3 with a physiologic extended-release profile are also under development and may be one of our options for therapy in the future. Stem cell technology may also be applied in the future to reverse the athyreotic state (21). As we learn more about the complexities of treating this condition, we are also learning that seemingly simple aspects of therapy such as achieving acceptable adherence to prescribed therapy and maintaining a TSH value within a desired target range cannot always be accomplished (22–24). In addition, different patient groups may require different approaches. Treating hypothyroidism in the elderly (24), for example, may not require the same therapeutic goals and frequency of monitoring as treatment of other populations such as those who are pregnant (25,26). In conjunction with the work of the American Thyroid Association Task Force on Thyroid Hormone Replacement and Use of Thyroid Hormone Analogues, we have organized a spring meeting that is devoted to these topics. We hope this meeting, scheduled in Washington, DC, on April 25 and 26, will be a forum conducive to exploring new research developments affecting these issues. As a starting point, the symposium will have a half-day of basic science that will review

Thyroid Storm Due to Inappropriate Administration of a Compounded Thyroid Hormone Preparation Successfully Treated with Plasmapheresis

Thyroid storm (TS) is a rare life-threatening condition that is characterized by fever and altered mental status precipitated by endogenous or exogenous critical events, illness/injury, acute iodine load, and thyroid or non thyroid surgery. A large number of thyroid extracts are available and extensively used, even though they are not recommended clinically in hypothyroid or euthyroid patients. Consumption of such products can be dangerous and result in life-threatening TS. Here, we report a case of TS caused by inadvertent intake of very high dosages of triiodothyronine (T3) and thyroxine (T4) in compounded thyroid extracts. Plasmapheresis may be considered an option for the management of exogenous TS. A 62-year-old woman with no significant past medical history presented with severe myalgia, fever, tachycardia, and blood pressure of 170/80 mmHg, which precipitated to an altered mental state within 24 hours. Neurological examination did not reveal any focal deficit or any signs of meningeal irritation. Further investigation revealed that she had been taking thyroid supplements. The patient had accidentally been supplied with a batch of thyroid extract pills that had an inadvertently high content of T4. Her free T3 (FT3) and free T4 (FT4) levels were found to be very high beyond the laboratory readable range (FT3>30 pg/mL; FT4>6.06 ng/dL; thyrotropin [TSH]=0.07 IU/mL). Three days post commencement of standard conservative management of TS, the patient developed posterior reversible encephalopathy syndrome, resulting in a seizure. She remained unresponsive and in a poor mental state. The confirmed exogenous etiology for TS led to a decision to conduct plasmapheresis. Plasmapheresis conducted for two consecutive days proved successful as a therapeutic measure for TS and improved her thyroid profile as well as her mental state. The inappropriate use of thyroid extracts in euthyroid and hypothyroid patients can result in life-threatening TS. Plasmapheresis is probably a life-saving treatment in patients who are exposed to amounts of thyroid hormone far in excess of that usually produced by the thyroid gland.

Thyroid Storm due to Inappropriate Administration of a Compounded Thyroid Hormone Preparation Successfully Treated with Plasmapheresis

Thyroid Storm due to Inappropriate Administration of a Compounded Thyroid Hormone Preparation Successfully Treated with Plasmapheresis

Association Between Low Serum Free Thyroxine Concentrations and Coronary Artery Calcification in Healthy Euthyroid Subjects

Considerable evidence suggests that hypothyroidism could promote atherosclerotic vascular changes. We planned this study to investigate whether serum free thyroxine (FT4) or thyroid-stimulating hormone (TSH) levels are associated with coronary artery calcification measured in healthy euthyroid subjects. A cross-sectional analysis was performed among subjects who visited our hospital for a health checkup. Among 1849 subjects, 669 (mean age 55.3±8.8 years; 392 men) with FT4 and TSH in the normal ranges were included after excluding those with diabetes, a history of current smoking and cardiovascular disease (CVD), or the use of drugs for hypertension, antithyroid drugs, or thyroid hormone preparations. Coronary artery calcium scores (CACS) were measured by multi-detector computed tomography. Subjects with a CACS >100 had lower FT4 levels than those with a lower CACS (p=0.017), whereas no difference was observed in the TSH levels among CACS categories. FT4 levels had an odds ratio of 0.06 for high CACS (95% confidence interval=0.01-0.74; p=0.028) after the adjustment for CVD risk factors. In multivariate regression analysis, CACS was negatively correlated with FT4 levels (β=-0.823, p=0.032), and the inverse association between FT4 and CACS remained significant only in men (p=0.011). FT4 levels were inversely associated with coronary artery calcification in euthyroid healthy subjects, especially in men independent of conventional CVD risk factors. Further studies are needed to validate whether subjects with decreased FT4 levels within the normal reference range are at a high CVD risk and have poor cardiovascular outcomes.

The incidence of thyroid function abnormalities and natural course of subclinical thyroid disorders, Tehran, I.R. Iran.

Despite the high prevalence of thyroid dysfunction, the epidemiology and natural course of these disorders have not been identified yet. The present survey was conducted to determine the incidence of thyroid dysfunction and natural course of subclinical thyroid disorders in an urban community of Tehran, I.R. Iran. Serum TSH and thyroperoxidase antibody (TPOAb) were measured at baseline and after 6.7 yr from a sample of 1999 randomly selected subjects aged≥20 yr, participants of the Tehran Lipid and Glucose Study (TLGS). Median TSH value and 2.5, 5, 95, and 97.5 TSH percentiles were determined at baseline using data obtained from 808 negative TPOAb subjects with no history of any thyroid disease or surgery, goiter, nodule, taking thyroid hormone preparations or anti-thyroid drugs. In those with abnormal TSH level, total T4 and T3 uptake were measured and free T4 index was calculated. Normal TSH reference range was 0.4-5.8 μU/ml according to the 2.5 and 97.5 TSH percentiles. The incidence rates of thyroid function abnormalities in 1000 subjects per year were as follows: clinical hypothyroidism: 0.28 in women and 0.21 in men; subclinical hypothyroidism: 11.59 in women and 4.69 in men; clinical hyperthyroidism: 1.4 in women and 0.21 in men; and subclinical hyperthyroidism: 5.72 in women and 3.62 in men. A significant increase was found in the frequency of positive TPOAb in women from 15.9 to 17.7% (p=0.006). Of 8 women with subclinical hypothyroidism at baseline, 5 remained unchanged, 1 became normal, and 1 developed clinical hypothyroidism at followup. Two women with subclinical hyperthyroidism normalized at follow-up. Of 2 men with subclinical hypothyroidism at baseline, 1 remained unchanged, whereas the other progressed to clinical hypothyroidism. After a 6.7 yr follow-up significant increase in the incidence of subclinical thyroid disorders was observed in both men and women, as compared to overt thyroid dysfunction. Increase in the prevalence of TPOAb positivity was observed only in women.

Predictors of Thyroid Hormone Initiation in Older Adults: Results From the Cardiovascular Health Study

Despite widespread use, there are no data on initiation of thyroid hormone use in older people. We report the prevalence of thyroid hormone use and predictors of thyroid hormone initiation in a population of older men and women. Thyroid hormone medication data were collected annually from 1989 to 2006 in community-dwelling individuals aged 65 years and older enrolled in the Cardiovascular Health Study (N = 5,888). Associations of age, sex, race, body mass index, education, and coronary heart disease with initiation were evaluated using discrete-time survival analysis. In 1989-1990, 8.9% (95% confidence interval 8.1%-9.7%) of participants were taking a thyroid hormone preparation, increasing to 20.0% (95% confidence interval 8.2%-21.8%) over 16 years. The average initiation rate was 1% per year. The initiation rate was nonlinear with age, and those aged 85 years and older initiated thyroid hormone more than twice as frequently as those aged 65-69 years (hazard ratio = 2.34; 95% confidence interval 1.43-3.85). White women were more likely to initiate thyroid hormone than any other race and sex group. Higher body mass index was independently associated with higher risk for initiation (p = .002) as was greater education (p = .02) and prevalent coronary heart disease (p = .03). Thyroid hormone use is common in older people. The indications and benefits of thyroid hormone use in older individuals with the highest rate of thyroid hormone initiation-the oldest old, overweight and obese individuals, and those with coronary heart disease-should be investigated.

High Frequency of and Factors Associated with Thyroid Hormone Over-Replacement and Under-Replacement in Men and Women Aged 65 and Over

Thyroid hormone use is common in older populations, but the frequency of over- or under-replacement is debated. We sought to describe the frequency of and factors associated with thyroid hormone over- or under-replacement in a population of older men and women. Participants were 3678 U.S. community dwelling individuals aged 65 yr or older enrolled in the Cardiovascular Health Study who had thyroid function tests in 1989-1990. Thyroid hormone users (n = 339) were identified and classified into low TSH (<0.45 mU/liter), euthyroid (0.45-4.5 mU/liter), and high TSH (>4.5 mU/liter). Of the 339 thyroid hormone users, 41% had a low TSH, 16% had a high TSH, and 43% were in the euthyroid range. In multivariable analyses, lower weight (P < 0.001) was independently associated with low TSH status. For every 10 kg lower weight, the likelihood of having low TSH increased by 65% [odd ratio (OR) 1.65; 95% confidence interval (CI) 1.31-2.07]. Those with renal insufficiency were less likely to have low TSH levels (P = 0.02). The presence of diabetes was independently associated with having low (OR 3.35; 95% CI 1.46-7.65) and high TSH levels (OR 2.66; 95% CI 1.14-6.21). There is a very high prevalence of thyroid function testing abnormalities in older people taking thyroid hormone preparations, particularly in those of low weight or with diabetes. Because of potential adverse cardiovascular and skeletal effects from over-replacement, older people represent a key population for increased TSH monitoring on therapy.