Levothyroxine Dose Research Articles

Postoperative Hypothyroidism Management: Weight-Based Levothyroxine Dosing Is an Oversimplification

Postoperative Hypothyroidism Management: Weight-Based Levothyroxine Dosing Is an Oversimplification

Modern diagnosis and treatment of papillary thyroid cancer

thyroid cancer is the most common malignant tumor of the endocrine glands, accounting for 1% of all cases of malignant neoplasms. According to the National Cancer Registry, 24,626 patients with thyroid cancer were identified in Ukraine for the period from 2014 to 2021, of which 4,556 were men (18.5%) and 20,070 were women (81.5%). Treatment of papillary thyroid cancer combines three methods: surgery, the use of radioiodine therapy, and hormone replacement therapy with levothyroxine drugs. The aim of this work, based on the example of a clinical case, was to analyze the patient's route, methods of diagnosis, and treatment of a thyroid neoplasm in accordance with current guidelines and recommendations. This clinical case highlights the importance of early diagnosis of TG diseases, namely papillary thyroid cancer. The patient turned to the clinic of the Ukrainian Scientific and Practical Center for Endocrine Surgery, Transplantation of Endocrine Organs and Tissues of MoH of Ukraine with complaints of an increase in the front surface of the neck and deterioration of the general condition for a long time. After analyzing the complaints, the patient was sent for a comprehensive examination, where an ultrasound of the TG revealed a mass, cytological examination confirmed a thyroid papillary cancer, grade 6. After undergoing preparation, the patient was referred for surgical intervention, namely extrafascial thyroidectomy. Combined treatment was carried out (operative intervention and treatment with the drug I131), and a suppressive dose of levothyroxine was prescribed, followed by dose correction and dynamic supervision by an endocrinologist. The described clinical case testifies to the high quality of diagnosis and treatment of a patient with thyroid papillary cancer in the conditions of a highly specialized endocrinological center. This approach fully meets the international requirements for the treatment of thyroid cancer. Despite the difficult epidemiological situation in Ukraine and the state of war, the patient was promptly referred to the Ukrainian Scientific and Practical Center for Endocrine Surgery, Transplantation of Endocrine Organs and Tissues, where she received the necessary assistance in full.

Features of achieving compensation of hypothyroisis in pregnant women

BACKGROUND: Hypofunction of the thyroid gland in women at the pre-pregnancy stage and during pregnancy is associated with a high risk of congenital hypothyroidism in children, as a result of which irreversible changes in the nervous system are formed. Despite the mandatory intake of potassium iodide preparations, pregnant women often develop gestational hypothyroidism, which requires the appointment of levothyroxine. Many women have episodic hypofunction of the thyroid gland before pregnancy, associated with various factors. Diagnosed hypothyroidism requires hormonal correction. The recommended dose of levothyroxine calculated by the patient’s weight is not always adequate to achieve TSH targets. In addition, there are pharmacological factors. Levothyroxine sodium preparations differ in bioavailability. The stability of drugs is affected by external factors and the composition of fillers from different manufacturers of drugs.AIM: To assess the dependence of TSH reduction on the method of taking levothyroxine in a population of pregnant women.MATERIALS AND METHODS: Statistical analysis and prospective study was carried out from 2019 to 2021. On the basis of the «Perinatal Center», Tyumen, women’s consultative and diagnostic department. Pregnant women with diagnosed primary subclinical and manifest hypothyroidism in the first trimester of pregnancy (n=76) were selected for cohort observation. All pregnant women were prescribed L-thyroxine Berlin-hemi. Other levothyroxine preparations were not used in order to exclude distortion of the results of the study.RESULTS: Pregnant women with hypothyroidism were divided into two groups according to the method of taking L-thyroxine: oral (n=54) and sublingual (n=22). A month later, TSH normalization was observed in 41 pregnant women in the oral group (76%) and in 22 pregnant women in the sublingual group (100%). Women who did not achieve hypothyroidism compensation were recommended sublingual administration without increasing the dose of L-thyroxine, provided that TSH was no higher than 4.0 mcME / ml. A TSH study a month later showed that all pregnant women achieved compensation. CONCLUSION: Based on the conducted research, it is shown that the more rational administration of levothyroxine sodium preparations is sublingual, since there is a slightly alkaline reaction in the oral cavity, which does not have a destructive effect, like gastric juice.

Effect of initial levothyroxine dose on neurodevelopmental and growth outcomes in children with congenital hypothyroidism

Effect of initial levothyroxine dose on neurodevelopmental and growth outcomes in children with congenital hypothyroidism

Factors related to bone mineral density in female patients receiving TSH-suppressive doses of levothyroxine for thyroid cancer

Background: Patients with thyroid cancer receive a high-dose thyroid hormone therapy after total thyroidectomy for suppression of thyroid stimulating hormone (TSH); this may affect bone mineral density (BMD). Identifying the common factors that affect BMD (including the duration of a high dose of thyroid hormone treatment) may, therefore, aid the delivery of appropriate and comprehensive care in such cases. Objective: To identify the factors related to BMD in female patients with thyroid cancer. Materials and Methods: This cross-sectional study evaluated data pertaining to the BMD and demographic characteristics of female patients with thyroid cancer. The patients were aged at least 40 years and received a high-dose thyroid hormone replacement therapy after total thyroidectomy at the Rajavithi Hospital between January 2004 and December 2019. The relationships between BMD and associated factors were analyzed using Pearson’s correlation and multiple linear regression. A p-value of less than 0.05 was considered statistically significant. Results: A total of 100 female patients with a mean age of 55.37 ± 11.36 (40-82) years and mean body mass index (BMI) of 24.8 ± 4.96 (15-40) were included; 60 and 56 of them were postmenopausal and coffee drinkers, respectively. High-dose thyroid hormone replacement therapy was received for a mean duration of 94.59±50.36 (3-210) months and 13 patients had a history of fractures; 60%, 30%, and 10% had normal BMD, osteopenia, and osteoporosis, respectively. The factors affecting BMD included the BMI (p-value <0.001) and postmenopausal status(p-value <0.001). Subgroup analyses showed the BMI to be the factor affecting BMD in the premenopausal group (p-value <0.001). Age, BMI, and calcium supplement intake were found to have an effect on the BMD in the postmenopausal group (p-value= 0.003, 0.002, and 0.020, respectively). The duration of high-dose thyroid hormone intake had no effect on the BMD in both the overall population (p-value= 0.558) and the subgroups based on the menopausal status (p-value = 0.437 and 0.380 in premenopausal and postmenopausal groups, respectively). Conclusion: In female patients who were treated for thyroid cancer, the factors affecting the BMD included the BMI in the premenopausal group and the age, BMI, and calcium supplementation in the postmenopausal group.

Investigating the Effect of Genetic Polymorphisms of Deiodinase Type 2 on Levothyroxine Dose Requirements in Patients with Hypothyroidism

Background: Hypothyroidism is the most abundant thyroid disorder worldwide. For decades, levothyroxine was the main effective pharmacological treatment for hypothyroidism. A variety of factors can influence levothyroxine dose, such as genetic variations. Studying the impact of genetic polymorphisms on the administration of medications was risen remarkably. Different genetic variations were investigated that might affect levothyroxine dose requirements, especially the deiodinase enzymes. Deiodinase type 2 genetic polymorphisms’ impact on levothyroxine dose was studied in different populations. Objective: To examine the association of the two single nucleotide polymorphism (SNP)s of deiodinase type 2 (rs225013 and rs225014) and levothyroxine dose requirements. Subjects and Methods: A cross-sectional study was conducted at Baghdad Center for Nuclear Medicine and Radiation Therapy located in Baghdad/ Iraq, from March to June 2022. Based on levothyroxine dose, the enrolled patients were divided into two groups: low dose group < 1.7 µg/kg/day and high dose group ≥ 1.7 µg/kg. Then genotyping analysis was done for both groups of the study. Results: The mean age of the participants was 40.35 ± 9.5 years with a mean body mass index of 30.61 ± 5.72 kg/m2. The mean levothyroxine doses in the low- and high-dose groups were 81.67 ± 30.74 µg/day and 161.67 ± 35.19 µg/day, respectively. Significant differences existed in the levels of TSH and TT4 between the study’s groups. Conclusion: This study indicated that the differences in levothyroxine dose, TSH, TT4 and TT3 levels were not associated with the DIO2 rs225013. Similarly, the differences in TSH, TT3 and TT4 levels revealed a non-significant association with DIO2 rs225014 except for levothyroxine dose which was higher in the patients who carried the wild type allele (TT).

Management of hypothyroidism in general practice- A review of guidelines Binod Dangal

Introduction:Hypothyroidism is a common complex chronic disease and levothyroxine is considered as a standard of care in the treatment of hypothyroidism. Untreated hypothyroidism leads to devastating complications. Careful and titrated management is necessary to have optimal functioning of thyroid glands to control overall metabolism. Diagnosis: Routine evaluation with Thyroid Function Test (TFT) is recommended to diagnose Hypothyroidism, Thyroid Peroxidase (TPO) Antibody testing is done to identify autoimmune etiology and the routine need of ultrasound is determined by findings in clinical examination. Treatment: Levothyroxine is standard of treatment for hypothyroidism. Regular follow up with Thyroid Stimulating Hormone (TSH) and titrated dose of levothyroxine is recommended.

Hypothyroid Myopathy: A Commonly Missed Complication of Hypothyroidism

Muscle disease is a known complication of hyperthyroidism as well as hypothyroidism. The muscle disease is associated with elevated creatine kinase and pain. This the case of a 63-year-old female who presented to the ED from her cancer therapy with elevated creatine kinase of 2,000 IU/L (International units/Liter). She reports muscle pain in her shoulders and hips for the past 3 days. Patient was recently diagnosed with hypothyroidism and has started on levothyroxine 75 mcg. Her Thyroid Stimulating Hormone (TSH) stays elevated at 65 IU (international units). Other autoimmune causes of elevated creatine kinase were excluded via testing, leaving hypothyroid myopathy as the only possible probable cause of this patient elevated creatine kinase. Muscle pain and creatine kinase should resolve with proper levothyroxine dose and compliance to therapy when patient becomes euthyroid. Unfortunately, the patient passed away from complications related to fall.

SNP rs11185644 in RXRA gene and SNP rs2235544 in DIO1 gene predict dosage requirements in a cross-sectional sample of hypothyroid patients

Background and purposePrimary hypothyroidism due to abnormality in the thyroid gland is the most common endocrine disease The recommended starting dose of levothyroxine replacement therapy is 1.6 µg/kg. This dose however is not optimal for every patient and dose adjustments are frequently done. Genetic polymorphisms in the absorption and metabolism pathway of levothyroxine are likely to influence its dose requirements. This study aimed to study the influence of genetic polymorphisms on levothyroxine replacement requirements.MethodsThis was a cross-sectional study. Participants were recruited through a private nutrition clinic and through announcements distributed in the University of Petra in Amman, Jordan between September 2020 and February 2021. Hypothyroid patients had already been on stable doses of levothyroxine for the previous 3 months. A questionnaire was distributed to collect demographic and clinical information and a blood sample was taken for DNA extraction and clinical biochemistry analysis. rs11249460, rs2235544, rs225014, rs225015, rs3806596, rs11185644, rs4588, rs602662 were analyzed using Applied Biosystems TaqMan™ SNP Genotyping Assays on Rotor-Gene® Q and rs3064744 by direct sequencing. SPSS and Excel were used to perform analysis.Results76 patients were studied. The equation we calculated to find predicted daily dose of levothyroxine (mcg/kg) is 3.22+ (0.348 for CT genotype of rs11185644, 0 for other genotypes) + 0.027*disease duration (years) − 0.014*age (years) − 0.434*T3 (pmol/L) levels+ (0.296 for CC genotype of rs2235544, 0 for other genotypes).ConclusionSNP rs11185644 in RXRA gene and SNP rs2235544 in DIO1 affect dose requirement in hypothyroid patients and if confirmed in larger trials they can be used to individualize thyroxine starting doses.

A rare case of SCHMID metaphyseal chondrodysplasia associated with hypothyroidism,growth hormone deficiency and celiac disease: case report.

The authors present a rare case of 4-year-2-month-old boy referred to our Unit for harmonious short stature, he had a waddling gait, subtle micromelia, and hyperlordosis, no special facies. The skeletal scan made the diagnosis of SCHMID metaphyseal chondrodysplasia. The first laboratory workup showed elevated thyroid stimulating hormone and anti-tissue transglutaminase immunoglobulin A. The duodenal biopsies confirmed the diagnosis of coeliac disease. Treatment of levothyroxine was initiated with a gluten-free diet .6 years later, his re-evaluation showed a low insulin-like growth factor 1 and low growth hormone peaks confirming the diagnosis of growth hormone deficiency, Growth hormone therapy was initiated with an adjusted dose of levothyroxine. Other causes of short stature should not be missed when diagnosing chondrodysplasia, and further investigations should be carried out to detect other concomitant disorders since metaphyseal chondrodysplasia is a rare cause for short stature while hypothyroidism and coeliac disease are relatively common.

Association between levothyroxine treatment for maternal subclinical hypothyroidism with negative TPOAb and early child neurodevelopment: A prospective real-world clinical trial.

Subclinical hypothyroidism (SCH) during pregnancy is reported to have detrimental impact on pregnancy and child development. However, its treatment indications require further investigation in different thyroid peroxidase antibody (TPOAb) status. This was a secondary analysis of a Chinese prospective cohort in a real-world setting. Pregnant women with gestational SCH were enrolled at the first antenatal visit and grouped by TPOAb positivity. Child neurodevelopment was assessed by the Gesell development diagnosis scale (GDDS) at one, three, six, 12, and 24 months of age. Subgroup analyses and sensitivity analyses were also conducted. ClinicalTrials.gov NCT01744743. From January 2012 to December 2013, a total of 171 participants were enrolled, including 116 of SCH with TPOAb negative (SCH-TPOAb [-]) and 55 of SCH with TPOAb positive (SCH-TPOAb [+]). Compared to women in the SCH-TPOAb (+) group, those in the SCH-TPOAb (-) group had lower thyroid-stimulating hormone (TSH) levels at enrollment and 12-16+6 gestational weeks, and unexpectedly higher TSH levels at 30-34+6 gestational weeks and delivery, with a correspondingly lower levothyroxine dosage throughout pregnancy (all p < 0.05). Offspring in the SCH-TPOAb (-) group displayed lower GDDS scores at one year old than did their counterparts (adjusted p < 0.05), which was possibly related to the worse thyroid function control of maternal SCH-TPOAb (-). No statistically significant difference was found in the GDDS assessments of children at one, three, six, and 24 months of age. These results were also confirmed in subgroup analyses stratified by maternal thyroid characteristics at enrollment, namely TSH levels, free levothyroxine (T4 ) levels, and anti-thyroglobulin antibody (TgAb) status, as well as in sensitivity analyses excluding participants with no levothyroxine treatment at enrollment. In the current clinical practice, infants born to mothers with SCH-TPOAb (-) displayed slightly lower neurodevelopmental scores at one year old than did those born to mothers with SCH-TPOAb (+) but this difference was not seen at two years.

Endocrinology for the hepatologist.

Endocrinology for the hepatologist.

Levothyroxine Dosing in Older Adults: Recommendations Derived From The Baltimore Longitudinal Study of Aging

ObjectiveAs thyroid hormone metabolism slows with advancing age, treatment dosing requirements change. Guidelines recommend titration from a low starting dose for older adults with hypothyroidism while providing weight-based estimates for younger populations. However, rapid replacement may be appropriate with acute onset of overt hypothyroidism. Therefore, a weight-based recommendation specific to older adults is needed. MethodsWe determined mean levothyroxine dose using actual and ideal body weight (IBW) ratios for the outcome of euthyroid on therapy relative to assay-specific and proposed age-specific ranges for independently living participants aged ≥65 years in the Baltimore Longitudinal Study of Aging. We examined risk factors to identify those at highest risk of overtreatment using regression analyses adjusted for potential covariables and clustering to account for multiple visits per individual. ResultsOne hundred eighty-five participants aged ≥65 years were on levothyroxine at 645 eligible visits. At euthyroid visits, participants were on an average dose of 1.09 μg/kg (1.35 μg/kg IBW), with 84% of euthyroid individuals on a dose of <1.6 μg/kg. Average euthyroid dose did not differ by sex using either actual body weight (ABW) or IBW. For obese individuals, mean euthyroid dose was lower if calculated using ABW (0.9 μg/kg vs 1.14 μg/kg; P < .01) but similar if calculated using IBW (1.42 vs 1.32 μg/kg IBW; P = .41) compared with those with a body mass index of <30. ConclusionThyroid hormone dose per body weight estimates for replacement in older adults (1.09 μg/kg ABW or 1.35 μg/kg IBW) are one-third lower than current weight-based dose recommendations for younger populations.

Automatic Levothyroxine Dosing Algorithm for Patients Suffering from Hashimoto's Thyroiditis.

Hypothyroidism is a condition where the patient's thyroid gland cannot produce sufficient thyroid hormones (mainly triiodothyronine and thyroxine). The primary cause of hypothyroidism is autoimmune-mediated destruction of the thyroid gland, referred to as Hashimoto's thyroiditis. A patient's desired thyroid hormone concentration is achieved by oral administration of thyroid hormone, usually levothyroxine. Establishing individual levothyroxine doses to achieve desired thyroid hormone concentrations requires several patient visits. Additionally, clear guidance for the dosing regimen is lacking, and significant inter-individual differences exist. This study aims to design a digital automatic dosing algorithm for patients suffering from Hashimoto's thyroiditis. The dynamic behaviour of the relevant thyroid function is mathematically modelled. Methods of automatic control are exploited for the design of the proposed robust model-based levothyroxine dosing algorithm. Numerical simulations are performed to evaluate the mathematical model and the dosing algorithm. With the help of the developed controller thyroid hormone concentrations of patients, emulated using Thyrosim, have been regulated under the euthyroid state. The proposed concept demonstrates reliable responses amidst varying patient parameters. Our developed model provides a useful basis for the design of automatic levothyroxine dosing algorithms. The proposed robust feedback loop contributes to the first results for computer-assisted thyroid dosing algorithms.

Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement.

Persistent symptoms in patients treated for hypothyroidism are common. Despite more than 20 years of debate, the use of liothyronine for this indication remains controversial, as numerous randomised trials have failed to show a benefit of treatment regimens that combine liothyronine (T3) with levothyroxine over levothyroxine monotherapy. This consensus statement attempts to provide practical guidance to clinicians faced with patients who have persistent symptoms during thyroid hormone replacement therapy. It applies to non-pregnant adults and is focussed on care delivered within the UK National Health Service, although it may be relevant in other healthcare environments. The statement emphasises several key clinical practice points for patients dissatisfied with treatment for hypothyroidism. Firstly, it is important to establish a diagnosis of overt hypothyroidism; patients with persistent symptoms during thyroid hormone replacement but with no clear biochemical evidence of overt hypothyroidism should first have a trial without thyroid hormone replacement. In those with established overt hypothyroidism, levothyroxine doses should be optimised aiming for a TSH in the 0.3-2.0 mU/L range for 3 to 6 months before a therapeutic response can be assessed. In some patients, it may be acceptable to have serum TSH below reference range (e.g. 0.1-0.3 mU/L), but not fully suppressed in the long term. We suggest that for some patients with confirmed overt hypothyroidism and persistent symptoms who have had adequate treatment with levothyroxine and in whom other comorbidities have been excluded, a trial of liothyronine/levothyroxine combined therapy may be warranted. The decision to start treatment with liothyronine should be a shared decision between patient and clinician. However, individual clinicians should not feel obliged to start liothyronine or to continue liothyronine medication provided by other health care practitioners or accessed without medical advice, if they judge this not to be in the patient's best interest.

Analysis of options for prescribing hormone replacement therapy after thyroid organ-sparing surgery

Background. Performing thyroid organ-sparing surgery primarily aims to preserve the quality of life. Organ-sparing surgery should be understood as hemithyroidectomy with mandatory removal of the isthmus and pyramidal lobe of the thyroid (if present). The choice of one or another concept of prescribing hormone replacement therapy remains debatable. The purpose of the study is to determine the proportion of patients who do not need replacement therapy with levothyroxine after organ-sparing surgery on the thyroid gland, among those who were prescribed replacement therapy immediately and one month after discharge from the hospital, as well as to analyze the factors causing hypothyroidism in people with hemithyroidectomy. Materials and methods. The first group included 82 patients with hemithyroidectomy who were prescribed replacement therapy immediately after discharge from the hospital. The second group included 61 patients with hemithyroidectomy. The administration of replacement therapy was postponed for one month. A month after the operation, clinical examinations and monitoring of thyroid-stimulating hormone and free thyroxine indicators were performed. Results. After one month of observation, 72 (87.8%) of 82 patients in the first group continued to take levothyroxine, and 8 (13.1%) of 61 persons in the second group began to take it. In the first group, there was a moderate direct correlation between thyroid-stimulating hormone level before surgery and levothyroxine dose one month after (Spearman’s correlation coefficient 0.304, p=0.009). It was found that the chances of continuing taking levothyroxine after one month in the first group were 47 times higher than the chances of prescribing levothyroxine after one month in the second group. The proportion of patients in the first group who continued to take levothyroxine after one month was significantly higher than the proportion of patients in the second group who started taking levothyroxine after one month (87.8±3.6% vs. 13.1±3.5%, p&lt;0.0001, Fisher’s exact test). Conclusions. Among patients who were prescribed hormone replacement therapy immediately after hemithyroidectomy, 12.2% did not need to continue taking levothyroxine after one month. Among persons in whom the administration of hormone replacement therapy was postponed for one month after hemithyroidectomy, 86.9% of patients did not require the use of levothyroxine in the future. The volume of the thyroid remnant ≤ 3.67 cm3 can be considered a predictor for hypothyroidism occurrence in the future, with a high risk of prescribing hormone replacement therapy. The study of such a factor as the ratio of the remnant thyroid volume to the body weight did not provide statistically reliable data for its use as a predictor of hypothyroidism occurrence in the postoperative period.

A Novel Development of Levothyroxine Sodium Orodispersible Mini Tablets for the Treatment of Pediatrics Hypothyroidism.

In pediatrics, developing new pharmaceutical forms that offer safety and efficacy is crucial to improve pediatric pharmaceutical care. Orodispersible tablets do not require swallowing because orodispersible tablets dissolve quickly in the mouth, reducing the risk of choking and making medication administration safer and more straightforward. There is no solid dosage form in the pharmaceutical market offering a unit dose of Levothyroxine for pediatric hypothyroidism patients. The objective of this study is to design and develop Orodispersible mini tablets of Levothyroxine Sodium (LT4 ODMTs) for pediatric doses. LT4 ODMTs were prepared by direct compression with 10 and 15 μg, respectively, using StarLac® and Disolcel® as excipients. United States Pharmacopeia (USP-43) guidelines evaluated and determined pre-compression properties and quality control parameters. The LT4 ODMTs met the specified limits for quality controls. The Drug Content Uniformity was 97%, Hardness was less than 2.5 N, Friability was less than 0.3%, Disintegration time was less than 25 s, and dissolution profiles (Q 80% > 45 s) followed the USP requirements. Additionally, stability and microbiology assays were realized. These formulations are optimal for developing new LT4 ODMTs suitable for treating pediatric hypothyroidism.

Acquired Hypothyroidism in Children.

Acquired hypothyroidism is generally also referred to as juvenile hypothyroidism. Hypothyroidism is due to the deficient secretion of thyroid hormones causing metabolic and neurological sequelae at the cellular level. It can present as overt hypothyroidism wherein the thyroid hormones (T4 and T3) secretion fall and thyrotropin (TSH) rises. Acquired hypothyroidism frequently presents between 9 and 11 y of age and is rarely seen before 4 y of age. Approximately 80% of the children and adolescents are asymptomatic at the time of diagnosis. Children with moderate to severe hypothyroidism often present for evaluation of poor growth, constipation, lethargy and/or dry skin. A detailed history and examination will provide us with enough clues for diagnosing hypothyroidism. Primary hypothyroidism can be diagnosed with raised TSH with subnormal levels of T3 and T4. Titres of thyroid antibodies - Anti-thyroperoxidase (TPO) and anti-thyroglobulin (ATG) antibodies, will be high in autoimmune hypothyroidism. Subclinical hypothyroidism is diagnosed with mildly elevated or high normal levels of TSH with free T4 being in the normal range. Insufficient secretion of thyrotropin from the pituitary causes central hypothyroidism. Acquired hypothyroidism is treated by replacement with levothyroxine. Regular monitoring of thyroid profile is necessary for adjusting doses of levothyroxine. Close monitoring and individualization of levothyroxine therapy is essential for normal growth and development of the child.

Clinical course of autoimmune thyroid diseases in women with prolactinomas: Results from a prospective study in a single tertiary centre

IntroductionSeveral retrospective and cross-sectional studies have revealed a higher prevalence of autoimmune thyroid diseases (AITD) with a predominance of autoimmune hypothyroidism in prolactinoma patients compared to the general population. To date, we have no data on the clinical course of AITD in these patients. The aim of this prospective study was to assess the clinical course of AITD in female patients with prolactinomas compared to an age- and thyroid-risk factors-matched control group. Materials and methodsThe study population consisted of 144 females (71 patients/73 controls) who underwent approximately a 6-year follow-up. Physical examination, thyroid ultrasound and laboratory testing (measurement of antibodies to thyroglobulin, thyroid peroxidase, TSH-receptor; serum TSH and FT4 levels) were performed twice – at the baseline and at the follow-up visits. ResultsAITD were diagnosed in 26.8% (n=19) of the patients and 9.6% (n=7) of the controls (p=0.007) at baseline visit. At the end of the follow-up (FU), these percentages increased to 33.8% (n=24) among the patients versus 12.3% (n=9) in the control group (p=0.002). Hypothyroidism was significantly more frequent in prolactinoma patients than in controls at the end of the study (19.7% vs. 4.1%; p=0.003). Two prolactinoma patients had hyperthyroidism at the baseline visit and restored euthyroid state with negative TSH-receptor antibodies during the follow-up. We did not observe hyperthyroidism in the control group. Among the hypothyroid subsets, the average daily levothyroxine dose at FU visit varied from 25 to 200mcg in the prolactinoma group compared to 25 to 50mcg in the control group. ConclusionsFemale patients with prolactinomas seem to be prone to autoimmune hypothyroidism. As a pathogenetic mechanism, we could suggest the selective immunomodulatory action of PRL predominantly on cell autoimmunity, complement activation and antibody-dependent cytotoxicity, resulting in earlier and more rapid progression of Hashimoto's thyroiditis towards hypothyroid state in genetically predisposed individuals.

Are probiotics, prebiotics, and synbiotics beneficial in primary thyroid diseases? Asystematic review with meta-analysis.

A number of studies indicate the presence of a thyroid-gut axis and the important influence of the gut microbiota on thyroid function. As prebiotics, probiotics and synbiotics show therapeutic potential in the treatment of intestinal dysbiosis, the aim of this review is to evaluate the efficacy of their supplementation in primary thyroid diseases. Electronic databases (Ovid MEDLINE, Embase, CENTRAL), registers of clinical trials, and grey literature up to 6 October 2022 were searched for randomised controlled trials (RCTs) meeting pre-specified inclusion criteria. The protocol was registered in PROSPERO (CRD42021235054). After screening 1,721 references, two RCTs were identified, which included 136 hypothyroid participants in total. Meta-analysis of the results after eight weeks of supplementation with predominantly Lactobacillus and Bifidobacterium strains indicated a clinically and statistically nonsignificant decrease in TSH (MD -0.19 mIU/L; 95% CI -0.43 to 0.06; I2= 0%), and no effect on fT3 levels (MD 0.01 pg/mL; 95% CI-0.16 to 0.18; I2= 0%). Data from single studies indicated no significant change in the levels of fT4, thyroid auto-antibodies, BMI, levothyroxine doses, and severity of symptoms measured with validated scales. Only constipation scores showed significant improvement (MD -8.71 points in the Faecal Incontinence Questionnaire; 95% CI -15.85 to -1.57; I2= 0%). Low-certainty evidence from two randomised trials, suggests that routine administration of probiotics, prebiotics or synbiotics may result in little to no benefit in patients with primary hypothyroidism.