Permanent Hypothyroidism Research Articles

Therapeutic implications in patients with subacute thyroiditis in the SARS-CoV-2 era

The purpose of this mini-review is to provide the latest information on the treatment of Subacute Thyroiditis (SAT) in the era of Coronavirus Disease 2019 (COVID-19). It is well documented that SAT has a significant impact on the quality of life of the patients, so early and proper diagnosis and treatment are necessary in order to reduce or even eliminate the severity of symptoms, frequency of relapses, and permanent hypothyroidism. This requires a multidisciplinary management approach in order to meet patients’ special needs. The present mini-review aims to summarize recent research evidence regarding the therapeutic management of SAT with special recommendations for COVID-19-associated SAT.

ODP531 Worsening of pretibial myxedema following repeated doses of radioiodine treatment in a patient with hyperthyroid Graves’ disease

Abstract Introduction The development of new-onset pretibial myxedema following radioiodine (RAI) treatment has been occasionally reported from the probable influences of thyrotropin receptor antibodies (TRAbs) similar to the RAI-associated Graves’ ophthalmopathy (GO). However, the worsening of pre-existing pretibial myxedema after RAI treatment has never been reported. Herein, we report an interesting case of fluctuating clinical course of pretibial myxedema following treatments of hyperthyroid Graves’ disease for over 3 years. Case Report A 49-year-old Thai woman with underlying hyperthyroid Graves’ disease with GO and pretibial myxedema for 1 year came to our hospital for relapsed hyperthyroidism and active, moderate-to-severe GO in 2019. A plague form of pretibial myxedema with indurated hyperpigmented lesion was found on both legs. Intravenous pulse methylprednisolone (IVMP) was given to control her active GO. Both GO and pretibial myxedema significantly improved after IVMP treatments. Then, RAI (30 mCi) was administered at 1 month later as a definitive treatment. Low dose of oral prednisolone (20 mg/ day) was also given before and after RAI treatment. Transient hypothyroidism developed at 4 months post-RAI and the estimated weights of the thyroid decreased from 60 grams to 30 grams. However, hyperthyroidism relapsed again within 6 months post-RAI treatment. At that time, her pretibial myxedema flared up slightly but her GO was still inactive. Eventually, a second dose of RAI (20 mCi) was given at 11 months apart from the first RAI administration. Low dose of oral prednisolone was also given. She developed post-radiation thyroiditis at 4 months after RAI with worsening of pretibial myxedema and mild exacerbation of GO. Topical corticosteroid ointment was given for pretibial myxedema and only local supportive measures was applied to treat GO. Finally, permanent hypothyroidism was achieved at 6 months after the second course of RAI. Currently, her pretibial myxedema is stable without further flareup. Conclusion Our case highlights the potential of RAI treatment to precipitate both GO and pretibial myxedema in patients with pre-existing skin lesions. Low dose prednisolone prophylaxis might not ensure preventative effect in exacerbation. Whether the risk of worsening of pretibial myxedema is higher in patients with persistent hyperthyroidism requiring a second dose of RAI is a question that warrants further studies. Presentation: No date and time listed

RF35 | PSAT257 The Severity of Subacute Thyroiditis Depends on Its Causative Agent

Abstract We retrospectively evaluated 402 patients referred to of the University Hospital of Pisa because of a SAT from January 2011 to December 2020. Neck pain was present in all patients; in 92 patients it was bilateral. A previous symptomatic involvement of the upper airways was reported by 97 patients. 32 patients did not receive pharmacological treatments, 16 were treated with non-steroidal anti-inflammatory drugs (NSAIDs) and 354 with glucocorticoids; the most common initial dose of prednisone was 25 mg (in 286 patients); the majority (n. 277 patients) were treated for 90 days. 88 patients experienced permanent hypothyroidism. Free thyroxine (FT4) values ​​correlated with those of the C reactive protein (CRP), erythrocyte sedimentation rate (ESR) and thyroglobulin (Tg) ​​(p <0.001 for all). Tg values ​​correlated with the severity of thyrotoxicosis and the levels of inflammatory markers. Values ​​of FT4, Tg, ESR and CRP in patients experiencing hypothyroidism were higher compared to those observed in patients who remained euthyroid after SAT. Values ​​of FT4, Tg, and CRP and incidence of hypothyroidism were higher in patients with bilateral neck pain compared to those experiencing unilateral neck pain. Similar differences were observed comparing patients who had respiratory symptoms prior to SAT to those who did not. Glucocorticoid treatment was associated with a shorter duration of neck pain (14 days) compared to those treated with NSAIDs (28 days) and those left untreated (28 days) (p <0.001). The initial dose of 25 mg (lower than that recommended by the recent guidelines of the American Thyroid Association - 40 mg/day) was sufficient to control the pain. The annual incidence of SAT was similar throughout the entire period of observation. The third quarter of the year was characterized by the highest number of cases compared to the other quarters in all years except 2012 and 2015, when there was a higher incidence in the first quarter, and in 2020, when most of the SAT cases occurred in the second and fourth quarters. In these peculiar periods thyrotoxicosis and inflammatory markers were higher and permanent hypothyroidism more common. The clusters of SAT in 2020 occurred within a month of the Covid-19 waves, while in the winter seasons 2011-12 and 2014-15 in Italy there was a higher incidence of the influenza virus A.H3N2. In conclusion, the severity of SAT depends upon the causative virus. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Monday, June 13, 2022 1:06 p.m. - 1:11 p.m.

Effect of Hematologic Values in Determining the Resolution of Subacute Thyroiditis and Long-Term Hypothyroidism Risk

Subacute thyroiditis (SAT), which can be considered a disease with infectious signs and parameters, can affect humans and lead to permanent hypothyroidism. Haematological parameters play an essential role in SAT; these parameters begin to normalise after the thyrotoxic phase; however, there is still a gap in knowledge about how these parameters play a role in SAT prognosis. Therefore, we wanted to investigate haematological parameters and their impact on treatment response and recovery phase in patients with SAT. 51 SAT patients and 44 healthy controls were included in the study. ESR, CRP, NLR and MPV were recorded at the diagnosis and after resolution. The changes in these parameters were compared to determine the resolution phase. The ratio of permanent hypothyroidism after one year was studied, and its relevance with these parameters at the time of diagnosis was explored. 36 of 51 SAT patients were female in the study (70.5%). The mean age was 45.53 ± 11.46 years. In the acute phase, WBC, Neutrophil, platelet, ESR, N/L, and P/L were significantly higher (p<0.05). In the recovery phase, MPV and lymphocyte count were significantly higher (p: 0.002 and p=0.002). WBC, CRP, and ESR had the highest AUC values in ROC analysis (0.990, 0.959, 0.907, p<0.05). P/L and N/L ratios also had higher ratios for the acute phase (0.807, 0.98, p<0.05, respectively). Δ ESR, Δ CRP, Δ N/L, and Δ P/L had the highest AUC for the recovery phase (AUC= 0.990, 0.899, 0889,0.800, p<0.5, respectively). Permanent hypothyroidism after one year was 9/42 (21.4%). In addition to ESR and CRP, NLR, PLR and MPV were also successfully used to estimate SAT activity and response to treatment. Moreover, a decrease in NLR and PLR and an increase in MPV were associated with the treatment response and resolution phase. However, these parameters did not determine the long-term risk of hypothyroidism.

Congenital hypothyroidism in India: A systematic review and meta-analysis of prevalence, screen positivity rates, and etiology.

Congenital hypothyroidism (CH) is the leading cause of preventable mental retardation, which is currently not universally screened in India. Knowledge of the country-specific prevalence of the disease can guide in establishing a universal screening program. We performed a systematic review and meta-analysis to assess the prevalence, screen positivity rates, compliance to recall and etiology of CH in India. The databases of PubMed, Embase, Google scholar and IMSEAR were searched on 1st October 2021. All observational studies reporting at least one of the outcomes of interest were included. Two reviewers independently extracted the data and appraised the quality of studies using the Joanna Briggs tool for prevalence studies. Estimates were pooled using a random-effects model with double arcsine transformation (MetaXL software). PROSPERO database registration number was CRD42021277523. Of the 2 073 unique articles retrieved, 70 studies were eligible for inclusion. The prevalence of CH (per 1 000 neonates screened) was 0·97 (95% confidence intervals/CI: 0·9, 1·04) in non-endemic areas (54 studies and 819 559 neonates), 79 (95% CI: 72, 86) in endemic areas (3 studies, 5 060 neonates), 50 (95% CI: 31, 72) in neonates born to mothers with thyroid disorders, and 14 (95% CI: 8, 22) in preterm neonates. At thyroid stimulation hormone cut-off of 20 mIU/L, the screen positivity rates were 5·6% (95% CI: 5·4%, 5·9%) for cord blood samples and 0·19% (95% CI: 0·18%, 0·2%) for postnatal sample. About 70% (95% CI: 70, 71) of screen positive neonates were retested with diagnostic tests. Among neonates with permanent hypothyroidism, thyroid dysgenesis 56·6% (95% CI: 50·9%, 62·2%) was more common than dyshormonogenesis 38·7% (95% CI: 33·2%, 44·3%). The prevalence of congenital hypothyroidism in India is higher than global estimates. Screen positivity rate was higher for cord blood screening when compared to postnatal screening. Compliance with confirmatory testing was higher for cord blood screening. The study was not funded by any source.

Impact of the COVID-19 pandemic on the incidence, seasonal distribution, and characteristics of subacute thyroiditis.

PurposeAn increasing number of cases of subacute thyroiditis (SAT) related to the coronavirus disease 2019 (COVID-19) and its vaccines continue to be published. The aim of this study was to investigate any change in the incidence and characteristics of SAT by comparing the pre-pandemic and pandemic periods.MethodsThis retrospective, single-center study included 432 newly-diagnosed SAT patients between January 2018 and December 2021. The annual frequency of SAT was calculated as the number of newly-diagnosed SAT cases divided by the total number of outpatients that year.ResultsThe frequencies of newly-diagnosed SAT were 0.136% in 2018, 0.127% in 2019, 0.157% in 2020, and 0.114% in 2021 (p = 0.19). While SAT patients were clustered in the autumn (35.1%) in 2018 and 2019, it was found that this cluster shifted to the winter (33.0%) in 2020 and 2021, in parallel with COVID-19 case peaks (p = 0.017). The patients were separated into two groups as pre-COVID-19 pandemic SAT (n = 272) and COVID-19 pandemic SAT (n = 160). The mean ages of the groups were similar. There were more male patients in the COVID-19 pandemic SAT group than in the pre-pandemic group (30.6% vs. 18.7%, p = 0.005). Frequencies of overt hyperthyroidism and median free-thyroxine levels were significantly higher in the COVID-19 pandemic SAT group (p = 0.029, p = 0.001). Treatment modalities, recurrence rates, and permanent hypothyroidism were similar in both groups.ConclusionWith the COVID-19 pandemic, although there was a change in seasonal variation of SAT and an increase in the number of male patients, there was no change in the incidence and clinical course of SAT.

Iatrogenic hyperthyroidism in primary congenital hypothyroidism: prevalence and predictive factors.

Primary congenital hypothyroidism (CH) is a preventable cause of mental retardation. Iatrogenic hyperthyroidism has occasionally been reported using the recommended LT4 dosage. Currently, information regarding iatrogenic hyperthyroidism and predictive factors for permanent hypothyroidism (P-CH) among Thai patients is lacking. The aim of this study is to determine the prevalence and factors for predicting iatrogenic hyperthyroidism at one month after LT4 initiation and for predicting P-CH in primary CH infants. This retrospective cohort study involved 87 infants with primary CH. Patients were classified by thyroid status at one month after LT4 initiation. At 3years, patients were reevaluated after LT4 cessation and assigned as P-CH or transient CH (T-CH). Differences between groups were analyzed. One month after LT4 initiation, 35.6% of patients were classified as having iatrogenic hyperthyroidism. An initial LT4 dose of 10.2μg/kg/day (sensitivity 64.5%, specificity 71.4%) was a suitable cutoff value for predicting iatrogenic hyperthyroidism, wherein 55.6 and 21.6% of patients were treated with initial doses of≥10.2 and <10.2μg/kg/day, respectively (p=0.004). Initial LT4 dose was the only predictive factor for thyroid status after initial treatment. At reevaluation, 47.4% of patients were diagnosed with P-CH. LT4 dosage at 3years of age was significantly higher in patients with P-CH (3.3 vs. 2.85μg/kg/day, p=0.02) and the only relevant factor for predicting P-CH. Iatrogenic hyperthyroidism is common among infants with primary CH when treated with the recommended LT4 dosage. LT4 dose was the only factor for predicting iatrogenic hyperthyroidism after LT4 initiation and the diagnosis of P-CH.

Transient vs permanent congenital hypothyroidism in Ontario, Canada: predictive factors and scoring system

Transient <i>vs</i> permanent congenital hypothyroidism in Ontario, Canada: predictive factors and scoring system

Evaluation of permanent and transient congenital hypothyroidism in cases referred from National Neonatal Screening Program.

The incidence of congenital hypothyroidism (CH) has increased world-wide. Lowering cut-off in screening programs has led to an increase in the rate of transient CH. We aimed to evaluate the rates of permanent and transient CH in cases referred from the screening program and to investigate the clinical and laboratory factors which predict transient CH. In 109 cases referred from the neonatal screening program to our hospital, from September 2015 to April 2018, 52 primarily diagnosed CH cases were prospectively evaluated. Regularly followed up, 44 CH cases were included in the study at the end of 3 years. 38.2 ± 1.31 weeks (w) and mean birthweight 3021.3 ± 389.6gram (g) in the transient CH group; both were significantly lower compared to permanent CH cases with 39.06 ± 1.33 w and 3375.3 ± 425.3g (P=0.025, P=0.007) respectively. Transient CH rate was found to be 50% (all hypoplastic) in the dysgenesis group and 73.3% in groups with normal and hyperplasic thyroid gland. While fT4 , thyroid-stimulating hormone, and thyroglobulin levels at diagnosis do not predict transient/permanent CH, levothyroxine (LT-4) dosage was significantly lower in the transient CH group in all years. The optimal cut-off value with highest sensitivity and specificity for LT-4 dosage as a predictive marker to differentiate transient CH from permanent CH was 2.27μg/kg/day (P=0.004; sensitivity: 71%, specificity: 83%) at 1st year, 1.85μg /kg/day (P=0.013; sensitivity: 66%, specificity: 72%) at 2nd year and 1.69μg /kg/day at 3rd year (P < 0.0001; sensitivity: 90%, specificity: 83%). Transient CH is more frequent than expected. Our results suggest that LT-4 requirement may be a good marker for predicting transient CH, while thyroid hormone levels at the time of diagnosis do not significantly predict permanent and transient CH. Therefore, infants with CH requiring LT-4 doses <2.27 μg/kg/day at 1st year, <1.85 μg /kg/day at 2nd year may be re-evaluated earlier to discriminate transient CH rather than at 3 years of age.

Gene mutations in children with permanent congenital hypothyroidism in Yunnan, China.

To investigate molecular and clinical characteristics of children with permanent congenital hypothyroidism (CH) in Yunnan, China. The clinical data of 40 children with CH diagnosed and treated in the First People's Hospital of Yunnan Province during January 2016 and January 2019 were retrospectively analyzed. All children were followed up to 3 years old, and Gesell intelligent score was evaluated at age of 1, 2 and 3 years, respectively. Developmental status and prognosis were evaluated. Next-generation sequencing (NGS) was used to screen all exons and exon-intron boundary sequences of the 27 known CH associated genes, and the relationship between genotypes and clinical phenotypes was analyzed. Among the 40 children, the thyroid related pathogenic gene mutations were detected in 23 cases with a rate of 57.5%, and a total of 32 mutations of 8 genes were detected. Mutations in DUOX2, TPO and TSHR genes were the most common ones with mutation frequencies of 65.9%(29/44), 11.4%(5/44) and 9.1%(4/44), respectively. DUOX2 gene mutations were detected in 17 children with CH, and a total of 17 mutation types were detected. p.K530* was the most common mutation in DUOX2 gene, accounting for 20.7%(6/29). There was no significant difference in physical development and intelligence assessment between children with DUOX2 heterozygous mutation and compound heterozygous mutations. None of patients could terminate medication at 3 years of the follow-up and all of them were provisionally assessed as permanent CH. The physical and mental development assessment of children with other gene mutations were also in the normal range. The detection rate of DUOX2, TPO and TSHR pathogenic mutations are high among children with permanent CH in Yunnan area, and no correlation is observed between gene mutation types and prognosis in children with CH.

Selenium Supplementation in Pregnancy-Maternal and Newborn Outcomes.

Background Several studies have suggested that increased oxidative stress during pregnancy may be associated with adverse maternal and foetal outcomes. As selenium is an essential mineral with an antioxidant role, our aim was to perform a systematic review of the existing literature reporting the effects of selenium supplementation during pregnancy on maternal and neonatal outcomes. Materials and Methods Six electronic databases (Medline, Embase, Cochrane Library, Web of Science, Scopus, and PubMed) were searched for studies reporting the effects of selenium supplementation during pregnancy and the postpartum period on maternal and neonatal outcomes. Only randomised controlled trials on human subjects reported in English and published up to October 2021 were included. Quality assessments were conducted using the modified Downs and Black quality assessment tool. Data were extracted using a narrative synthesis. Results Twenty-two articles were included in our systematic review (seventeen reported on maternal outcomes, two on newborn outcomes, and three on both). Maternal studies reported the effects of selenium supplementation in the prevention of thyroid dysfunction, gestational diabetes, pregnancy-induced hypertension/preeclampsia, oxidative stress, postpartum depression, premature rupture of membranes, intrauterine growth retardation, breastmilk composition, and HIV-positive women. Newborn studies reported the effects of maternal selenium supplementation on foetal oxidation stress, foetal lipid profile, neonatal hyperbilirubinemia, and newborn outcomes in HIV-positive mothers. The majority of studies were inappropriately designed to establish clinical or scientific utility. Of interest, four studies reported that selenium supplementation reduced the incidence of thyroid dysfunction and permanent hypothyroidism during the postpartum period by reducing thyroid peroxidase and thyroglobulin antibody titres. Conclusion The evidence supporting selenium supplementation during pregnancy is poor and there is a need for appropriately designed randomised controlled trials before routine use can be recommended.

Prevalence of congenital hypothyroidism and transient neonatal hyperthyrotropinemia in babies born to hypothyroid mothers at a tertiary care hospital

Objectives: Transient neonatal hyperthyrotropinemia (TNH) is being increasingly recognized in the developed world as a risk factor for the development of permanent hypothyroidism. It is defined as transient elevation of serum thyroid-stimulating hormone (TSH) levels between 10 and 20 mIU/L after 48 h of life with normal free thyroxine levels, returning to normal after 2 weeks of life. Factors associated with TNH as well as its consequences on growth and development are lesser known at present. Maternal hypothyroidism, both overt and subclinical, is known to have adverse neurodevelopmental outcomes in children. Maternal hypothyroidism is also one of the risk factors for developing TNH. This study aimed to measure the prevalence of congenital hypothyroidism (CH) and TNH, and evaluate neurodevelopmental outcomes in children born to hypothyroid mothers. Material and Methods: Sixty-three consecutive neonates born to mothers diagnosed as hypothyroid during pregnancy were enrolled for the study. Fifty neonates underwent evaluation for thyroid functions and development till 6 months of age, after excluding preterm and sick babies requiring intensive care. Results: None of the babies had CH. The prevalence of TNH was found to be 6.0% (n = 3/50), with TSH values normalizing by 4 weeks of age. All babies with TNH were female. Development assessment done till 6 months of life was normal for all babies. Conclusion: Our study describes the prevalence of TNH and short-term development outcomes in babies born to hypothyroid mothers. The role of TNH in the development of permanent hypothyroidism is still a debatable topic, and larger studies are needed to assess its implications on linear growth, academic performance, as well as language and intellectual development.

The New Entity of Subacute Thyroiditis amid the COVID-19 Pandemic: From Infection to Vaccine.

This is a review of full-length articles strictly concerning subacute thyroiditis (SAT) in relation to the SARS-CoV-2 virus infection (SVI) and COVID-19 vaccine (COV) that were published between the 1st of March 2020 and the 21st of March 2022 in PubMed-indexed journals. A total of 161 cases were reported as follows: 81 cases of SAT–SVI (2 retrospective studies, 5 case series, and 29 case reports), 80 respective cases of SAT–COV (1 longitudinal study, 14 case series, 17 case reports; also, 1 prospective study included 12 patients, with 6 patients in each category). To our knowledge, this represents the largest cohort of reported cases until the present time. SAT–SVI was detected in adults aged between 18 and 85 years, mostly in middle-aged females. SAT–COVID-19 timing classifies SAT as viral (synchronous with infection, which is an original feature of SATs that usually follow a viral infection) and post-viral (during the recovery period or after infection, usually within 6 to 8 weeks, up to a maximum 24 weeks). The clinical spectrum has two patterns: either that accompanying a severe COVID-19 infection with multi-organ spreading (most frequent with lung involvement) or as an asymptomatic infection, with SAT being the single manifestation or the first presentation. Either way, SAT may remain unrecognized. Some data suggest that more intense neck pain, more frequent fever, and more frequent hypothyroidism at 3 months are identified when compared with non-SAT–SVI, but other authors have identified similar presentations and outcomes. Post-COVID-19 fatigue may be due to residual post-SAT hypothyroidism. The practical importance of SAT–SVI derives from the fact that thyroid hormone anomalies aggravate the general status of severe infections (particular concerns being tachycardia/arrhythmias, cardiac insufficiency, and ischemic events). If misdiagnosed, SAT results in unnecessary treatment with anti-thyroid drugs or even antibiotics for fever of unknown cause. Once recognized, SAT does not seem to require a particular approach when compared with non-COVID-19 cases, including the need for glucocorticoid therapy and the rate of permanent hypothyroidism. A complete resolution of thyroid hormone anomalies and inflammation is expected, except for cases with persistent hypothyroidism. SAT–COV follows within a few hours to a few weeks, with an average of 2 weeks (no particular pattern is related to the first or second vaccine dose). Pathogenesis includes molecular mimicry and immunoinflammatory anomalies, and some have suggested that this is part of ASIA syndrome (autoimmune/inflammatory syndrome induced by adjuvants). An alternative hypothesis to vaccine-related increased autoimmunity is vaccine-induced hyperviscosity; however, this is supported by incomplete evidence. From what we know so far concerning the risk factors, a prior episode of non-SVI–SAT is not associated with a higher risk of SAT–COV, nor is a previous history of coronavirus infection by itself. Post-vaccine SAT usually has a less severe presentation and a good outcome. Generally, the female sex is prone to developing any type of SAT. HLA susceptibility is probably related to both new types of SATs. The current low level of statistical evidence is expected to change in the future. Practitioners should be aware of SAT–COV, which does not restrict immunization protocols in any case.

Optimal Thyroid Hormone Replacement Dose in Immune Checkpoint Inhibitor-Associated Hypothyroidism Is Distinct from Hashimoto's Thyroiditis.

Background: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many advanced cancers but are recognized to cause treatment-limiting immune-related adverse events (IrAE). ICI-associated thyroiditis is the most common endocrine IrAE and usually resolves to permanent hypothyroidism. Optimal thyroid hormone replacement in these patients remains unclear. We report the levothyroxine (LT4) dose needed to achieve stable euthyroid state in patients with hypothyroidism from ICI-associated thyroiditis, with comparison to patients with Hashimoto's thyroiditis (HT) and athyreotic state. Methods: We conducted a retrospective study of adults with ICI-associated hypothyroidism treated with LT4 at an academic medical center. Patient data were collected from the electronic medical record. Cases had ICI exposure followed first by hyperthyroidism and then subsequent hypothyroidism. Controls were HT (positive thyroid autoantibodies, requiring LT4) and athyreotic (total thyroidectomy or radioiodine ablation, requiring LT4) patients. Patients with central hypothyroidism, thyroid cancer, pregnancy, gastrointestinal stromal tumors, and use of L-triiodothyronine were excluded. Our primary outcome compared LT4 dose needed to achieve euthyroid state (thyrotropin 0.3-4.7 mIU/L over >6 consecutive weeks) for ICI-associated hypothyroidism, HT, and athyreotic patients, considering the impact of age and possible interfering medications by linear regression modeling. Secondary analysis considered the impact of endocrine specialty care on the time to euthyroid state. Results: One hundred three patients with ICI-associated thyroiditis were identified. Sixty-six of the 103 patients achieved euthyroid state; 2 with intrinsic thyroid gland function recovery and 64 on LT4. The mean LT4 dose achieving stable euthyroid state was 1.45 ± standard deviation (SD) 0.47 mcg/[kg·day] in ICI-associated hypothyroidism, 1.25 ± SD 0.49 mcg/[kg·day] in HT, and 1.54 ± SD 0.38 mcg/[kg·day] in athyreotic patients, using actual body weight. The difference in dose between ICI-associated hypothyroidism and HT was statistically significant (p = 0.0093). Dosing differences were not explained by age or use of interfering medications. Conclusions: ICI-associated thyroiditis represents an increasingly recognized cause of hypothyroidism. Our study demonstrates that patients with ICI-associated hypothyroidism have different thyroid hormone dosing requirements than patients with HT. Based on our findings and prior reports, we recommend that in patients with ICI-associated thyroiditis LT4 therapy be started at an initial weight-based dose of 1.45 mcg/[kg·day] once serum free thyroxine levels fall below the reference range.

Prediction of Transient or Permanent Congenital Hypothyroidism

Prediction of Transient or Permanent Congenital Hypothyroidism

Hysterosalpingography with Oil-Soluble Contrast Medium Does Not Increase Newborn Hypothyroidism.

Objective Hysterosalpingography (HSG) with oil-soluble contrast medium (OSCM) improves pregnancy rates in women with idiopathic infertility. However, OSCM has high iodine content and slow clearance resulting in potential iodine excess. If pregnancy occurs, this could impact fetal thyroid gland development and function. We aim to determine the effect of a preconceptional OSCM HSG on the thyroid function of the neonate. Design and Patients. This was a retrospective analysis of newborn TSH data for a cohort of neonates conceived within six months of an OSCM HSG in the Auckland region, New Zealand, from the years 2000 to 2019. Thyroid-stimulating hormone (TSH) levels of these newborns were obtained from newborn screening, which is routinely performed for all children at 48–72 hours of life. The primary outcome was the incidence of permanent or transient congenital hypothyroidism in this cohort. Results Of 146 babies included, all had normal TSH levels with values ranging from 1 to 7 mIU/L on the whole blood analysis of a capillary heel sample using the Perkin–Elmer AutoDelfia assay. Conception during the first 3 cycles following an OSCM HSG was 76%; however, TSH levels in this group were not higher than those conceived in later cycles. Conclusion Preconceptional OSCM HSG did not increase the risk of congenital hypothyroidism in the New Zealand scenario.

An update on thyroid disorders in the postpartum period.

To review the pathophysiology, diagnosis and management of postpartum thyroid dysfunction, and related management of thyroid disorders during lactation. We reviewed the literature on postpartum thyroid dysfunction and management of thyroid disorders during lactation. The postpartum period is characterized by a rebound from the immunotolerance induced by pregnancy. Routine thyroid function screening is not recommended for asymptomatic women in the postpartum period. Testing thyroid function should be considered at 6-12-week postpartum for high-risk populations, including women with a previous episode of postpartum thyroiditis, Graves' disease, or those with Hashimoto's thyroiditis on thyroid hormone replacement, known thyroid peroxidase antibody positivity, type 1 diabetes mellitus, other nonthyroidal autoimmune disease, or chronic hepatitis C. A serum TSH should also be checked in the setting of postpartum depression or difficulty lactating. If patients have thyrotoxicosis, new-onset or recurrent Graves' disease must be differentiated from postpartum thyroiditis, because the management differs. Periodic thyroid function testing is recommended following recovery from postpartum thyroiditis due to high lifetime risk of developing permanent hypothyroidism. Levothyroxine, and the lowest effective dose of antithyroid drugs, (propylthiouracil, methimazole, and carbimazole) can be safely used in lactating women. The use of radiopharmaceutical scanning is avoided during lactation and radioactive iodine treatment is contraindicated. Diagnosing postpartum thyroid dysfunction is challenging, because symptoms may be subtle. A team approach involving primary care providers, endocrinologists, and obstetricians is essential for transitioning thyroid care from the gestational to the postpartum setting.

Clinical characteristics of patients with subacute thyroidits and factors affecting development hypothyroidism after subacute thyroiditis

IntroductionSubacute thyroiditis (SAT) is typically a self-limiting, inflammatory disease. Patients can experience hypothyroidism during or after an episode. We examined the clinical characteristics based on laboratory and imaging studies in patients with SAT and possible factors contributing to the development of permanent hypothyroidism after SAT.Material and methodsWe retrospectively examined medical records of patients diagnosed with SAT at one medical facility in Turkey. Patients known to have previous thyroid disease, those with &lt;6 months of follow-up after resolution of SAT, and those who lacked sufficient data for analysis were excluded. Of the 283 patients identified 119 met all inclusion criteria. We extracted data on demographics, laboratory tests, neck pain and other symptoms, ultrasonography findings, medication use, and SAT recurrence. We examined the relationships between these variables and development of permanent hypothyroidism.ResultsThe patients were 42 years old on average, and 78% were women. Most patients (70%) described flu-like symptoms before neck pain started; accordingly, 57% had initially visited a specialty other than endocrinology before SAT was diagnosed, and 28% had received antibiotics for misdiagnosed upper respiratory tract infection. In all, 10 patients (8.4%) developed permanent hypothyroidism after SAT. These patients had received steroids significantly longer than did those without permanent hypothyroidism (mean 17.7 vs. 8.9 weeks; P = .021). Development of hypothyroidism was significantly lower among patients with thyrotoxicosis.ConclusionsThe diagnosis of SAT can be challenging. Patients who require longer-term steroids after SAT and who have recurrent SAT should be closely monitored for development of hypothyroidism.

Is hemithyroidectomy sufficient in unilateral benign nodular goitre?

Multinodular goiter is a common disease. If only one thyroid lobe is affected, hemithyroidectomy may be preferred to reduce complication and hormone replacement therapy. However, completion thyroidectomy may be required later. The aim of the study was to evaluate the role of completion thyroidectomy in patients who develop nodules after hemithyroidectomy, and we aimed to find the ratio of patients who required hormone replacement for permanent hypothyroidism. Patients who underwent hemithyroidectomy for benign nodular goitre between January 2012 and June 2017 were analyzed. The age of the patients, gender, number of nodules and dimension of the largest nodule, preoperative fine needle aspiration biopsy results, and postoperative histopathology findings were recorded. The need for completion thyroidectomy and need for postoperative L-thyroxine treatment were based on these parameters. A total of 170 patients were included in the study. During the follow-up period new nodule or progression in existing nodule was observed in 23% (39 patients) of the cases. Permanent hypothyroidism requiring L-thyroxine treatment was observed in 31% (53 patients) of the cases. In this study, young age, multiple nodules and toxic nodular goitre diagnosis were noted to be independent risk factors that contributed to progression diseases in cases operated for benign nodular goitre. Due to low reoperation risk and acceptable permanent hypothyroidism rates, hemithyroidectomy is a viable option for benign goitre cases. The patients should be on follow-up for possible complications, especially hypothyroidism, for at least a year.

Etiological, clinical, and laboratory evaluation of congenital hypothyroidism and determination of levothyroxine (LT4) dose at treatment interruption in differentiating permanent vs. transient patients.

Congenital hypothyroidism (CH) is the most common cause of preventable but irreversible mental retardation in children, although the risk has been widely abolished by national neonatal screening programs. The aim of this study was to determine, (a) the cause of CH, (b) the etiological cause of persistent CH and (c) to investigate the role of laboratory and clinical data in predicting persistent and transient CH. Patients diagnosed with CH, who started L-thyroxine treatment and were followed up for at least three years were included. Patient data were reviewed retrospectively. Serum thyroid hormones were measured four weeks after discontinuation of therapy at age three or earlier. Cases with a thyroid-stimulating hormone (TSH) value of >10 mIU/mL were accepted as permanent hypothyroidism, while cases with normal TSH values for six months after cessation were accepted as transient hypothyroidism. There were 232 treated cases, of whom 108 (46.6%) were female, and 169 (72.8%) were eventually diagnosed with transient CH. The best cut-off point for predicting permanent status was determined as LT4 cut-off dose ≥1.45 mcg/kg/day. The median (range) duration of L-thyroxine treatment in transient hypothyroid cases was 24 (range: 6-36) months, and treatment was discontinued before the age of three years in 64%. There were 232 treated cases, of whom 108 (46.6%) were female, and 169 (72.8%) were eventually diagnosed with transient CH. The best cut-off point for predicting permanent status was determined as LT4 cut-off dose ≥1.45 mcg/kg/day. The median (range) duration of L-thyroxine treatment in transient hypothyroid cases was 24 (range: 6-36) months, and treatment was discontinued before the age of three years in 64%.