Thyroid Hormone Replacement In Patients Research Articles

Clinical and Biochemical Comparative Evaluation of Thyroid Hormone Replacement in Patients with Hypothyroidism Due to Autoimmune Thyroiditis and Total Thyroidectomy

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Central hypothyroidism: are patients undertreated?

Thyroid hormone replacement in central hypothyroidism (CHT) is more difficult than in primary hypothyroidism (PHT), putting patients at risk for inappropriate substitution. In this study, we compared the dosage of thyroid hormone replacement in patients with CHT with that of patients with PHT. In addition, we explored and compared quality of life (QoL) between both groups, based on two questionnaires, the SF-36 health score and the thyroid-specific ThyPRO score. This is a monocentric, cross-sectional study, performed at the Ghent University Hospital (Belgium). We included 82 patients in total, 41 patients with CHT and 41 patients with PHT. At the time of inclusion, all patients had to have a stable dose of levothyroxine over the past 6 months and patients with PHT needed to be euthyroid (defined as having a thyroid-stimulating hormone level within the reference range, 0.2-4.5 mU/L). All data were retrieved from medical files, and questionnaires on QoL were self-administered. The CHT and PHT groups were comparable regarding age and BMI. There was no significant difference between both groups regarding total daily dose of levothyroxine (100 (93.75-125.00) vs 107.14 (75.00-133.93) μg in CHT and PHT, respectively; P = 0.87) or daily dose of levothyroxine per kg body weight (1.34 (1.16-1.55) vs 1.55 (1.16-1.82) μg/kg, respectively; P = 0.13). Serum levels of fT4 (P = 0.20) and fT3 (P = 0.10) also did not differ between the two groups and both were in the normal (mid)range for the two groups. Regarding QoL, patients with CHT scored worse in terms of depressive and emotional symptoms, impaired daily and social life. We could demonstrate a difference in QoL between patients with CHT and PHT. Although patients with CHT had a somewhat lower levothyroxine substitution dose than patients with PHT, this difference was also not significant and probably does not explain the difference in QoL.

Brain [18F]Fluorodeoxyglucose Metabolism Assessment under Hypothyroidism and Recombinant Human Thyroid-Stimulating Hormone in Comparison with Thyroid Hormone Replacement in Patients Submitted to Total Thyroidectomy

Objective: To compare brain metabolism using [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) in total thyroidectomy patients during hypothyroidism (levothyroxine withdrawal) or under recombinant human thyroid-stimulating hormone (rhTSH) against levothyroxine intake. Methods: A total of 12 patients were randomly divided into two groups. One group underwent the first [18F]FDG PET/CT brain scan after levothyroxine withdrawal (hypothyroidism condition) and repeated the scan 6 months later during regular levothyroxine intake (replacement condition). The other group underwent the first [18F]FDG PET/CT scan after receiving an rhTSH injection and maintained regular levothyroxine intake (rhTSH condition), and repeated the scan 7 months later during regular levothyroxine intake without rhTSH administration. The intra-group regional brain metabolisms were compared. Results: Under the hypothyroidism condition, brain metabolism was significantly reduced, namely in the bilateral pre-frontal, temporal, anterior cingulate, and primary motor cortices, insula, and striatum (uncorrected voxelwise p < 0.005); No significant differences were found between the rhTSH and replacement conditions. Conclusion: rhTSH administration could be a better option than levothyroxine withdrawal for 131I treatment, serum thyroglobulin measurement, or radioiodine scanning for patient follow-up.

Alternative routes of levothyroxine administration for hypothyroidism

The aim of the article is to present the basics of oral levothyroxine (LT4) absorption, reasons why patients may have persistently elevated serum thyroid stimulation hormone (TSH) levels, and alternative strategies for LT4 dosing. Although oral LT4 tablets are most commonly used for thyroid hormone replacement in patients with hypothyroidism, case studies report that liquid oral LT4, intravenous, intramuscular, and rectal administration of LT4 can successfully treat refractory hypothyroidism. Hypothyroidism is one of the most common endocrine disorders encountered by primary care physicians and endocrinologists. LT4 is one of the most widely prescribed medications in the world and it is the standard of care treatment for hypothyroidism. Generally, hypothyroid patients will be treated with LT4 tablets to be taken orally, and monitoring will occur with routine serum thyroid tests, including TSH concentrations. However, many patients fail to maintain serum TSH levels in the target range while managed on oral LT4 tablets. A subset of these patients would be considered to have poorly controlled hypothyroidism, sometimes termed refractory hypothyroidism. For these patients, optimization of ingestion routines and alternative formulations and routes of administration of LT4 can be considered, including oral liquid, intravenous, intramuscular, and even rectal formulations.

High prevalence of non-thyroidal illness syndrome in patients at long-term care facilities

Patients in acute care hospitals are often transferred to long-term care (LTC) when there is an expectation for a lengthy recovery. Prolonged non-thyroidal illness syndrome (NTIS) creates a state of hypothyroidism. We aimed to investigate the prevalence of NTIS in patients at LTC facilities. A cross-sectional study at University Hospitals and Rehabilitation and Skilled Nursing facility was performed. Four groups: control (n:33), intensive care unit (ICU) (n:34), long-term care hospital (LTCH) (n:50), and long-term care on chronic ventilatory support (LTCVS) (n:30). Serum levels of TSH, free T4 (FT4), free T3 (FT3), and interleukin 6 (IL6) measured at admission day in controls, within 48 h of admission in the intensive care group, between days 31 and 120 in the LTC hospital group and days 31 and 6 years in the LTC on chronic ventilatory support group. Serum FT3 levels were lower in groups intensive care unit ICU, LTCH, and LTCVS than control. Low serum FT3 levels were observed in 80% ICU, 54% LTCH, 37% LTCVS, and 6% control patients. Low serum FT4 levels were observed in 32% ICU, 16% LTCH, and 20% LTCVS patients. Both low serum FT4 and FT3 levels were observed in 32% ICU, 16% LTCH, and 13% LTCVS patients. Serum IL6 and FT3 levels showed a negative correlation. NTIS is highly prevalent in patients in LTC, creating a state of persistent hypothyroidism. The effects of thyroid hormone replacement in patients at LTC with non-thyroidal illness deserve further investigation.

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

MON-599 Physician Reported Challenges in the Management of Hypothyroidism

Introduction: Thyroid hormone use is widespread and levothyroxine is one of the most commonly prescribed medications in the United States. Although prior research has focused on over- and undertreatment and patient dissatisfaction with thyroid hormone replacement, little is known about physician reported barriers to managing thyroid hormone replacement in patients. Methods: We surveyed physician members of the Endocrine Society, the American Academy of Family Practice and the American Geriatrics Society using the modified Dillman method of survey administration. Respondents were asked to rate barriers to the management of thyroid hormone therapy. As patient requests for tests and treatments was a highly ranked barrier, we conducted a multivariable analysis to determine correlates with physician report of patient requests as a barrier. Results: The survey response rate was 63% (359/566). Patient non-compliance (70%), patient requests for tests and treatments (46%) and multiple providers managing thyroid hormone replacement (45%) were reported as somewhat to very likely barriers to the management of thyroid hormone therapy. Endocrinologists (p=0.045) and physicians with high case volume (p=0.035) were more likely to report patient requests for tests and treatments as a barrier, whereas physicians with more years in practice were less likely to do so (11-20 years: p=0.025; >20 years: p<0.001). Common patient requests reported by surveyed physicians included requests for preparations other than synthetic thyroxine (52%), adjusting thyroid hormone dose based on symptoms when biochemically euthyroid (52%), maintaining thyroid stimulating hormone (TSH) below normal range (32%) and adjusting thyroid hormone dose according to serum T3 level (21%). Conclusion: In addition to patient non-compliance and multiple providers managing thyroid hormone, physicians reported that patient requests for tests and treatments is a common barrier to managing thyroid hormone therapy. Endocrinologists, high case volume physicians and those with fewer years in practice were more likely to report patient requests as a barrier. Along with addressing over- and undertreatment and patient dissatisfaction with thyroid hormone, key to improving care is also understanding physician reported barriers to managing thyroid hormone replacement. Furthermore, more research is needed to understand factors associated with physician perception that patient requests are a barrier.

Hypothyroidism in Clinical Practice

Hypothyroidism in Clinical Practice

The efficacy of thyroid hormone replacement therapy in patients with hypothyroidism and OSAHS: a Meta analysis

Objective:To systematically evaluate the impact of thyroid hormone replacement in patients with OSAHS and hypothyroidism.Method:The related case-control study of thyroid hormone replacement in patients with OSAHS and hypothyroidism had been searched from Cochrane Library, PubMed, CNKI, Chinese Biomedical Literature Database, Wanfang Resource Database.The case-control study which were in line with the condition need to be evaluated the quality and to be extracted in literature. The RevMan 5.3 and STATA softwares were applied to carry out the Meta analysis.Result:Seven literatures of case-control study were included. The Meta analysis showed that: After the thyroid hormone replacement, the patient's AHI index, TSH index, LSaO₂ index were significantly improved (P< 0.05). The AHI index statistical results of the patients were [SMD= 3.15, 95%CI: (4.36-1.94), P< 0.000 01; I²= 96%], TSH index were [SMD= 4.15,95%CI: (1.15-7.15), P= 0.007; I²= 99%], LSaO₂ index were [SMD=-1.08, 95%CI: (-1.46--0.70), P< 0.000 01, I²= 68%].Conclusion:The use of thyroid hormone replacement can effectively reduce the patient's hypothyroidism symptoms and AHI symptoms.

Thyroid Hormone Replacement in Patients Following Thyroidectomy for Thyroid Cancer.

Thyroid hormone replacement therapy in patients following thyroidectomy for thyroid cancer, although a potentially straightforward clinical problem, can present the clinician and patient with a variety of challenges. Most often the problems are related to the dose and preparation of thyroid hormone (TH) to use. Some patients feel less well following thyroidectomy and/or radioiodine ablation than they did before their diagnosis. We present evidence that levothyroxine (L-T4) is the preparation of choice, and keeping the thyroid-stimulating hormone (TSH) between detectable and 0.1 mU/L should be the standard of care in most cases. In unusual circumstances, when the patient remains clinically hypothyroid despite a suppressed TSH, we acknowledge there may be as yet unidentified factors influencing the body’s response to TH, and individualized therapy may be necessary in such patients.

Thyroid hormone metabolism in heart failure: iodothyronine deiodinases in focus

Heart disease is the leading cause of death worldwide and no efficient treatment against this threatening condition exists. Based on their recognized regulatory action on cardiovascular system, thyroid hormones emerged as a good alternative for patients with heart disease. Although many studies have shown beneficial effects of thyroid hormone replacement in patients with heart failure, many questions are still unsolved. Thus, the purpose of this review was to discuss changes in thyroid hormone economy with special emphasis on thyroid hormone metabolism in models of heart failure. Severe illness, such as heart failure, is characterized by changes in thyroid hormone economy, characterized by decreased serum T3 and increased serum rT3, a condition called the 'low T3-syndrome'. Unlike other animal models of thyroid status derangement during systemic illness, some clinical and experimental studies have observed compensatory stimulation of the hypothalamus-pituitary-thyroid axis in patients and models of heart failure. In this context, induction of type 3 deiodinase is the main cause of decreased T3. This is uniquely reminiscent of the pathophysiology of the 'consumptive hypothyroidism', which has previously been described in patients with large D3-expressing tumors. Tight regulation of cardiac T3 levels occurs in heart failure and understanding the pathophysiology of this phenomenon might support future researches to find new efficient strategies to treat heart failure.

Les dyshormonémies des affections non thyroïdiennes

Abnormalities in the circulating levels of thyroid hormones, without evidence of coexisting thyroid or pituitary gland disease can be observed in all general diseases. These nonthyroidal illnesses (NTIS) are the result of complex mechanisms that combine the effect of some drugs, cytokines, nutritional and endocrine factors at all levels of the thyrotropic axis, from the hypothalamus to the cellular transporters and nuclear receptors of thyroid hormones. The patterns of NTIS depend on the underlying disease and its severity. Thirtyfive years after the initial description, the pathophysiological significance of these anomalies remains controversial. One of the dilemma of NTIS is whether the hormone responses represent an adaptive and normal, physiologic response to conserve energy and protect against hypercatabolism in case of aggression, or whether it is a maladaptive response contributing to a worsening of the disease. This debate is not just a theoretical question, because in the first case the process must be respected, in the other case a vigorous treatment to restore circulating thyroid hormone levels is justified. There have been very few clinical studies designed to address whether the substitution with thyroid hormone is advantageous, and there is at current time no permissive evidence for the use of thyroid hormone replacement in patients with NTIS. But the clinical context, the choice of the molecule or of the dose and the way of administration were not necessarily the most relevant. Theoretically, stimulation of thyreotrope axis used a continuous infusion of TRH seems to provide clinical benefit. With the expectation that randomized clinical trials will provide demonstration of NTIS treatment efficiency, the question might remain unanswered for several more years.

Thyroid Testing and Thyroid Hormone Replacement in Patients with Sleep Disordered Breathing

The current literature recommends that patients who have symptoms of sleep disordered breathing should be evaluated for hypothyroidism. Thyroid hormone replacement therapy has been reported by some authors to be effective in treating obstructive sleep apnea in hypothyroid patients. The present study prospectively evaluated the prevalence of hypothyroidism in 1,000 consecutively presenting patients who came to the office for evaluation of snoring or obstructive sleep apnea syndrome. The authors also examined the efficacy of treatment for hypothyroidism on sleep apnea in patients with both disorders. Of the 1,000 patients, routine thyroid testing was performed on 834; only 10 of these patients (1.2%) were discovered to have previously undiagnosed clinical hypothyroidism. Four of the 10 patients with newly diagnosed clinical hypothyroidism had obstructive sleep apnea syndrome, and they received thyroid hormone replacement therapy. Once these four patients achieved a euthyroid state, repeat polysomnography showed that there was no significant difference between their pre- and posttreatment respiratory disturbance index. Based on the results of our study, we conclude the following: 1) The prevalence of hypothyroidism in patients who are evaluated for sleep disordered breathing is no greater than that of the general population. 2) Thyroid replacement therapy results in little or no improvement in sleep apnea in patients with clinical hypothyroidism. 3) Routine thyroid function screening is not indicated for patients who are being evaluated for sleep disordered breathing.

Effect of Chronic and Acute Thyroid Hormone Reduction on Perioperative Outcome

Effect of Chronic and Acute Thyroid Hormone Reduction on Perioperative Outcome