Effects of atrial fibrillation screening according to thyroid function: Post-hoc analysis of the randomized LOOP study.

PURPOSE: Subclinical thyroid dysfunction is a marker for atrial fibrillation (AF) and stroke risk. This study explored the effects of AF screening according to thyroid-stimulating hormone (TSH) levels. METHODS: An AF screening trial (the LOOP study) was analyzed post-hoc according to baseline TSH. The primary outcome was stroke or systemic embolism (SE). Secondary outcomes included major bleeding, all-cause death, and the combination of stroke, SE, and cardiovascular death. RESULTS: TSH measurement was available in 6003 of 6004 trial participants, 1500 randomized to implantable loop recorder (ILR) screening for AF and anticoagulation upon detection vs. 4503 to usual care; mean age was 74.7±4.1 years and 2836 (47%) were women. AF detection was approximately triple for ILR vs usual care across TSH tertiles (adjusted p-interaction=0.44). In the first tertile, screening was associated with decreased risk of the primary outcome (hazard ratio 0.52 [0.30-0.90]; p=0.02) and stroke, SE, or cardiovascular death (hazard ratio 0.54 [0.34-0.84]; p=0.006) compared to usual care, while no effect was observed among participants with higher TSH (adjusted p-interaction 0.03 and 0.01, respectively). There was no effect on other outcomes. Analyses of continuous TSH or excluding those with abnormal TSH or thyroid medication showed similar results. CONCLUSION: AF screening and subsequent treatment was associated with decreased stroke risk among participants with low TSH, though the yield of screening was similar across TSH levels. TSH may be useful as a marker to indicate benefit from AF screening vs. overdiagnosis and overtreatment. These findings should be considered exploratory and warrant further study. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT0203645.

The Effects of Intra-Articular Triamcinolone and Autologous Protein Solution on Metabolic Parameters in Horses.

Intra-articular corticosteroids are a popular treatment choice for joint-associated pain and inflammation in horses despite recent work on the metabolic effects of these drugs. The goal of this project was to compare metabolic effects between intra-articular (IA) triamcinolone acetonide (TA) and an autologous protein solution (APS). Five mixed-breed geldings (4-9 years) were utilized for this project. Three identical and consecutive 28-day treatment blocks were used, with metacarpophalangeal IA treatments consisting of equal volumes of saline, a commercially available APS, or 9 mg of TA. Regular plasma and serum samples were collected for ACTH, cortisol, glucose, insulin, and thyroid hormone analysis, in addition to thyrotropin-releasing hormone (TRH) and oral sugar tests (OSTs). Significant treatment effects of IA TA were present at 48 h post-injection in both the TRH and the OST. There was also significant suppression by IA TA of baseline ACTH and cortisol between 2 h and 96 h post-treatment, hyperglycemia between 12 h and 48 h, and hyperinsulinemia at 32 h post-treatment. There were no treatment effects with respect to any measured thyroid hormones, nor were there any significant treatment effects of APS noted. Results suggest at least 2 days and up to 7 days should elapse between a single 9 mg IA TA treatment and OST and/or TRH testing. This study found that TA exhibits significant effects on ACTH, cortisol, glucose, and insulin, while the APS does not.

The association of higher thyroid stimulating hormone levels in the normal range with unexplained infertility: A cross-sectional study.

Background: Since thyroid hormones have an essential role in energy production, early development of the human placenta, embryo development, and implantation, abnormalities in thyroid function can significantly affect pregnancy outcomes. Objective: The present study aimed to investigate the effect of higher thyroid-stimulating hormone (TSH) levels in the normal range in euthyroid women with unexplained infertility. Materials and Methods: In this cross-sectional study, we evaluated the data for 300 euthyroid women aged between 18 and 39 yr with normal TSH levels ( ≤ 5 mIU/L) referred to Yazd Reproductive Sciences Institute, Yazd, Iran from December 2018-March 2021 in 2 groups: the case group (with unexplained infertility) and the control group (with male factor infertility). Finally, age, body mass index, and serum levels of TSH were extracted from participants' medical records and compared between groups. Results: The mean age and TSH level of participants were 31.52 ± 3.52 yr and 1.24 ± 2.59 mIU/L, respectively. 142 women (47.3%) had TSH < 2.5, and 158 women (52.7%) had TSH ≥ 2.5 mIU/L. The women with unexplained infertility had significantly higher TSH levels than controls in the same normal range (0.62 vs. 0.64 mIU/L, p < 0.001). Although a more significant proportion of women in the case group had TSH levels > 2.5 mIU/L, we did not find a significant association between TSH levels and age or body mass index. Conclusion: Women with unexplained infertility have a higher level of serum TSH in the normal range ( ≥ 2.5 mIU/L) than the control group. So, the effect of TSH treatment on these women should be considered.

Association of Free Thyroxine with Progression-Free Survival in Intermediate and High Risk Differentiated Thyroid Cancer.

CONTEXT: Supraphysiologic thyroxine (T4) doses are used in intermediate and high-risk patients with differentiated thyroid cancer (IR/HR-DTC) to suppress tumor progression by thyrotropin (TSH). However, preclinical data suggest that T4 can also act as a growth stimulus for cancer, but there is no clinical evidence supporting this claim. OBJECTIVE: We analyzed the association between free T4 (FT4) and progression-free survival (PFS) in patients with IR/HR-DTC. METHODS: This longitudinal cohort study, approved by multi-institutional review board, included patients with IR/HR-DTC treated uniformly with total thyroidectomy, radioiodine (RAI), and TSH suppression therapy, with at least three TSH and FT4 values available. Association between FT4 and PFS at landmarks 6, 12, and 18 months was assessed by Kaplan-Meier survival curves, while competing risks were assessed through Cox proportional hazards model. RESULTS: From 739 screened patients 382 met the inclusion criteria and were characterized by a median age of 46 (34-59) years, 64.1% women, treated with a median RAI dosage of 159 (110-410) mCi. During follow up of 7.1 (3.4-12.7) years 34.6% experienced disease progression.Elevated FT4, observed in 29.3% of patients, was not associated with worse PFS (HR 0.9, CI 0.54-1.5, p=0.69), while age (HR 1.02, CI 1.004-1.04, p=0.01), tumor size (HR 1.15, CI 1.04-1.28, p=0.01), and metastases to the lateral neck lymph nodes (HR 2.9, CI 1.7-4.74, p<0.001), bones (HR 4.87, CI 1.79-13.3, p=0.002), and brain (HR 5.56, CI 2.54-12.2, p<0.001) were associated with shorter PFS. CONCLUSIONS: Contrary to preclinical evidence, elevated FT4 levels do not affect PFS in patients with IR/HR-DTC.

Bidirectional negative relationship between thyrotropin and kidney function during alcohol intoxication in males.

Introduction: Despite a well-established direct toxic effect of alcohol on renal cells, there is a salutary dose-dependent effect of alcohol consumption on common laboratory parameters related to kidney performance. Alcohol also impacts thyroid hormones, while thyroid status modulates kidney function. The modulation of kidney parameters with thyrotropin (TSH) and thyroid status indicates a possible interaction between alcohol, kidney, and thyroid functions. This retrospective study was conducted to test the hypothesis that the positive effect of alcohol use on the estimated glomerular filtration rate (eGFR) is mediated by alcohol's effect on thyroid hormones. Methods: We reviewed the electronic medical records of 767 hospitalized adult patients free of thyroid disorders who received medical care in the Mayo Clinic Health System from June 2019 through June 2022 and had blood alcohol concentration (BAC), serum TSH, and serum creatinine measured during the hospitalization. We calculated the eGFR using both the re-expressed Modification of Diet in Renal Disease (MDRD II) study equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine equation. Results: We found a significant relationship of BAC with eGFR (CKD-EPI) and TSH in males only. BAC had a positive association with eGFR (b = 0.24, p = 0.0001) and negative with TSH (b=-0.17, p = 0.006). The covariance between the two outcomes (eGFR and TSH) was negative (b = -0.12, p = 0.049). The path analyses using the eGFR MDRD II equation were not significant in males, whereas females had no significant path analyses with either of the eGFR equations. Discussion: We observed that BAC influences both eGFR and TSH, whereas eGFR and TSH influence each other. After considering important covariates (e.g., age, body mass index, diabetes mellitus, cardiovascular disease, chronic kidney disease, and chronic liver disease) and the negative bidirectional effect of TSH and eGFR, a positive impact of BAC on eGFR was observed in males.

Impact of non-severe infections on cortisol and thyroid stimulating hormone baseline levels in hospitalized patients: A monocentric cross-sectional study.

Objective. The hormonal balance is dependent on the internal and external stimuli. The baseline cortisol (BC) and thyroid stimulating hormone (TSH) levels have been observed to vary and have a predictive value in critical illness settings. Few reports have studied their variation in non-severe acute illness. The present study aims to describe the variation of BC and TSH levels and to determine the factors influencing BC and TSH levels in patients admitted with non-severe acute illness. Patients and Methods. This is a cross-sectional study of patients admitted to Infectious Diseases and Endocrinology units at the Department of Endocrinology-Diabetology and Internal Medicine at Tahar Sfar University Hospital between March 15th and September 15th, 2020. BC and TSH levels were obtained during the hospitalization. Results. A total of 143 patients were included in this study with 75 presenting with infection. All infections were community-acquired and predominantly non-severe. The BC levels were higher in patients with infection (p=0.004), especially those admitted via the emergency department (p=0.009) with a fever (p=0.015). The BC positively correlated with the temperature (p=0.002, r'=0.350), CRP levels (p=0.002, r'=0.355), neutrophil to lymphocyte ratio (p=0.045, r'=0.235), and SOFA score (p=0.023, r'=0.262). On the other hand, TSH levels were comparable in the presence of infection (p=0.400). TSH levels did not correlate with the fever, the severity of infection, or inflammation biomarkers. Both BC and TSH did not predict unfavorable outcomes in non-severe infected patients. Conclusion. In patients admitted with critical acute infections, the BC levels seem to indicate a relatively more severe infectious state. On the other hand, TSH levels did not show significant variations in these patients.

Correlation of serum thyrotropin and thyroid hormone levels with diabetic kidney disease: a cross-sectional study.

OBJECTIVE: The relationship between thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and diabetic kidney disease (DKD) is still controversial, and this study analyzed the correlation between TSH, FT3, FT4 and DKD in patients with type 2 diabetes mellitus (T2DM). METHODS: T2DM patients (1216) were divided into five groups based on serum TSH, FT3, and FT4 levels, differences in urinary albumin excretion rate (UACR), estimated glomerular filtration rate (eGFR) were compared. Binary logistic regression verified independent correlations among TSH, FT3, FT4 and UACR, eGFR. TSH and FT3 predictive values for DKD were analyzed using receiver operating characteristic (ROC) curves. RESULTS: The prevalence of albuminuria with decreased eGFR was higher in T2DM patients with subclinical hypothyroidism and overt hypothyroidism than that in patients with normal thyroid function. TSH positively correlated with UACR (r = 0.133, p < 0.001) and positively correlated with eGFR (r = -0.218, p < 0.001), FT3 negatively correlated with UACR (r = -0.260, p < 0.001) and positively correlated with eGFR (r = 0.324, p < 0.001). With the change from the lower normal level to the increased level of TSH and the change from the higher normal level to the reduced level of FT3, the prevalence of albuminuria gradually increased, the prevalence of decreased eGFR gradually increased in TSH groups and FT3 groups. After adjusting for age, BMI, duration of diabetes, TPOAb, TGAb, smoking, drinking, hypertension, the use of anti-diabetic medications (metformin, sodium-glucose cotransporter 2 inhibitors), HbA1c, CRP, TC, TG, LDL-C, and HDL-C, both TSH and FT3 correlated with increased UACR (TSH: OR 1.253, p = 0.001; FT3: OR 0.166, p < 0.001) and decreased eGFR (TSH: OR 1.245, p < 0.001, FT3: OR 0.579, p < 0.001), but this correlation of TSH with eGFR < 60 mL/min/1.73 m2 was not found in male. The area under the ROC curve (AUC) for FT3 was greater than that for TSH (FT3: 0.64; TSH: 0.61). CONCLUSIONS: Increased TSH and reduced FT3 levels were associated with DKD in T2DM patients, but in a sex-dependent manner. FT3 had a higher predictive value for DKD.

TSHR Gene (rs179247) Polymorphism and Susceptibility to Autoimmune Thyroid Disease: A Systematic Review and Meta-Analysis.

BACKGRUOUND: Both Graves' disease (GD) and Hashimoto's thyroiditis (HT) are classified as autoimmune thyroid diseases (AITDs). It has been hypothesized that changes in the thyroid-stimulating hormone receptor (TSHR) gene may contribute to the development of these conditions. This study aimed to analyze the correlation between the TSHR rs179247 gene polymorphism and susceptibility to AITD. METHODS: We conducted a thorough search of the Google Scholar, Scopus, Medline, and Cochrane Library databases up until March 2, 2024, utilizing a combination of relevant keywords. This review examines data on the association between TSHR rs179247 and susceptibility to AITD. Random-effect models were employed to assess the odds ratio (OR), and the findings are presented along with their respective 95% confidence intervals (CIs). RESULTS: The meta-analysis included 12 studies. All genetic models of the TSHR rs179247 gene polymorphism were associated with an increased risk of developing GD. Specifically, the associations were observed in the dominant model (OR, 1.65; P<0.00001), recessive model (OR, 1.65; P<0.00001), as well as for the AA genotype (OR, 2.09; P<0.00001), AG genotype (OR, 1.39; P<0.00001), and A allele (OR, 1.44; P<0.00001). Further regression analysis revealed that these associations were consistent regardless of the country of origin, sample size, age, and sex distribution. However, no association was found between TSHR rs179247 and the risk of HT across all genetic models. CONCLUSION: This study suggests that the TSHR rs179247 gene polymorphism is associated with an increased risk of GD, but not with HT, and may therefore serve as a potential biomarker.

Neonatal Thyrotoxicosis in Infants of Mothers with Graves' Disease Treated for Radioiodine-Induced Hypothyroidism: A Literature Review.

Fetal and neonatal thyrotoxicosis occurs in up to 5% of pregnancies in mothers with Graves' disease (GD). This condition is caused by stimulating antibodies against the thyrotropin receptor (TRAbs) that cross the placenta and may stimulate the fetal thyroid, typically in the second half of pregnancy. GD is often treated with radioiodine, resulting in hypothyroidism in most patients, but TRAbs can persist for several years. Even if a pregnant mother is hypothyroid after radioiodine therapy or surgery, her TRAbs can still, although rarely, induce fetal hyperthyroidism. In this review, we first present two cases of neonatal hyperthyroidism in mothers with GD who became hypothyroid after prior radioiodine therapy, identified through a 10-year analysis of the National Perinatal System in Slovenia. Based on these cases, we provide an overview of existing data on this rare clinical condition in neonates. We also discuss the underlying mechanisms and clinical outcomes based on currently available data. In conclusion, our review highlights the importance of careful monitoring during pregnancy in all women with GD, even in those well managed after radioiodine therapy or surgery.

Association Between Subclinical Thyroid Dysfunction and Cognitive Decline: Findings From the ELSA-Brasil Study.

BACKGROUND: Thyroid dysfunction has been associated with cognitive decline and dementia. However, the role of subtle thyroid hormone alterations in cognitive function is still debatable. METHODS: Participants without overt thyroid dysfunction aged 35-74 years at baseline were evaluated in 3 study waves (2008-2010, 2012-2014, and 2017-2019). We assessed baseline thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Cognitive performance was evaluated every 4 years in each wave using 10-word immediate and late recall, word recognition, semantic (animals category) and phonemic (letter f) verbal fluency, and the trail-making B-version tests. A global composite z-score was derived from these tests. The associations of TSH, FT4, and FT3 levels with cognitive decline over time were evaluated using linear mixed-effect models adjusted for sociodemographic, clinical, and lifestyle variables. RESULTS: In 9 524 participants (mean age 51.2 ±â€…8.9 years old, 51% women, 52% White), there was no association between baseline TSH, FT4, and FT3 levels and cognitive decline during the follow-up. However, increase in FT4 levels over time was associated with faster memory (ß = -0.004, 95% CI = -0.007; -0.001, p = .014), verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0005, p = .021), executive function (ß = -0.004, 95% CI = -0.011; -0.003, p < .001), and global cognition decline (ß = -0.003, 95% CI = -0.006; -0.001, p = .001). Decrease in FT4 levels over time was associated with faster verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0004, p = .025) and executive function (ß = -0.004, 95% CI = -0.007; -0.0003, p = .031) decline. CONCLUSIONS: An increase or decrease in FT4 levels over time was associated with faster cognitive decline in middle-aged and older adults without overt thyroid dysfunction during 8 years of follow-up.

US-based, Prospective, Blinded Study of Thyrotropin Receptor Antibody in Autoimmune Thyroid Disease.

CONTEXT: Bioassays provide information on the functionality of thyrotropin receptor antibodies (TSH-R-Ab) and thus may offer more clinical utility than binding assays. OBJECTIVE: In this prospective, blinded, US-based study, the clinical performance of several TSH-R-Ab assays was compared. SETTING: US endocrinology clinic. SUBJECTS: One hundred sixty-two unselected, consecutive, well-documented patients with various thyroid diseases and healthy controls. INTERVENTION(S): Blinded TSH-R-Ab measurements. MAIN OUTCOME MEASURE(S): Sensitivity and specificity of 4 TSH-R-Ab assays. RESULTS: The 4 TSH-R-Ab assays were negative in all 42 patients without autoimmune thyroid disease (AITD). In 104 patients with Graves' disease (GD), irrespective of the disease duration, TSH-R-Ab positivity was present in 65 (63%), 67 (65%), and 87 (84%) for the Cobas and Immulite binding assays and stimulatory TSH-R-Ab [thyroid-stimulating immunoglobin (TSI)] bioassay, respectively (TSI vs Immulite P < .0025, TSI vs Cobas P < .0009). Fifteen newly diagnosed GD patients were all positive in the TSI bioassay, but only 11 (73%) were positive in the Cobas and Immulite binding assays. Nine GD patients with biochemical subclinical hyperthyroidism were TSI-positive but Immulite- and Cobas-negative. Two GD patients were blocking TSH-R-Ab [thyroid-blocking immunoglobin (TBI)]-positive and TSI-negative, and the Immulite and Cobas were positive in both. Additional serum samples from AITD patients that consisted of 30 TBI-positive and 10 TSI-positive samples were blindly tested in the binding assays. Only 6 of the 10 TSI-positive samples were positive in both binding assays, and 30 and 28 of the TBI-positive samples were positive in the Cobas and Immulite assays, respectively. CONCLUSION: Binding TSH-R-Ab assays are less sensitive than TSI bioassays and are not specific for stimulating antibodies. Measuring the function of TSH-R-Ab in a bioassay can provide useful information to clinicians.

Relationship Between Serum Thyrotropin Levels and Metabolic Diseases in Older Adults.

CONTEXT: Subclinical hypothyroidism is associated with metabolic diseases; however, it remains controversial in older individuals. OBJECTIVE: This work aimed to investigate the relationship between thyrotropin (TSH) levels and metabolic diseases. METHODS: In this cross-sectional study, sampling was conducted from nationally representative general communities from 31 provinces in mainland China. A total of6791 older (aged ≥65 years) and 55 303 young participants (aged 18-64 years) were selected after excluding individuals with overt hyperthyroidism or overt hypothyroidism. According to the kit, TSH reference range (0.27-4.2 mU/L) and the age-specific TSH range previously formulated (an upper limit of 8.86 mU/L for older adults and 6.57 mU/L for young adults), the older adults and young adults were separately divided into 4 groups based on their TSH levels. Main outcome measures included anthropometric assessments, serum concentrations of thyroid functions, and various metabolic parameters. RESULTS: In contrast to young adults, there was no significant increase in the prevalence of any metabolic disorders assessed in the slightly elevated TSH group (TSH 4.21-8.86 mU/L) compared to the euthyroid group (TSH 0.27-4.2 mU/L) among older adults. After adjusting for interference factors, a TSH level higher than 8.86 mU/L was found to be an independent risk factor for low high-density lipoprotein cholesterol (OR, 1.84; 95% CI, 1.14-2.98) and dyslipidemia (OR, 1.49; 95% CI, 1.09-2.04) when compared to the euthyroid group in older adults. CONCLUSION: Slightly elevated TSH levels are not associated with an increased risk of metabolic diseases in older adults. Therefore, we recommend raising the upper limit of the TSH range for individuals aged 65 years and older.

Defining gestational thyroid dysfunction through modified non-pregnancy reference intervals: an individual participant meta-analysis.

BACKGROUND: Establishing local trimester-specific reference intervals for gestational TSH and FT4 is often not feasible, necessitating alternative strategies. We aimed to systematically quantify the diagnostic performance of standardized modifications of center-specific non-pregnancy reference intervals as compared to trimester-specific reference intervals. METHODS: We included prospective cohorts participating in the Consortium on Thyroid and Pregnancy. After relevant exclusions, reference intervals were calculated per cohort in thyroperoxidase antibody-negative women. Modifications to the non-pregnancy reference intervals included an absolute modification (per 0.1 mU/L TSH or 1 pmol/L FT4), relative modification (in steps of 5%) and fixed limits (upper TSH limit between 3.0 to 4.5 mU/L and lower FT4 limit 5-15 pmol/L). We compared (sub)clinical hypothyroidism prevalence, sensitivity and positive predictive value (PPV) of aforementioned methodologies with population-based trimester-specific reference intervals. RESULTS: The final study population comprised 52,496 participants in 18 cohorts. Optimal modifications of standard reference intervals to diagnose gestational overt hypothyroidism were -5% for the upper limit of TSH and +5% for the lower limit of FT4 (sensitivity 0.70, confidence interval [CI] 0.47-0.86; PPV 0.64, CI 0.54-0.74). For subclinical hypothyroidism, these were -20% for the upper limit of TSH and -15% for the lower limit of FT4 (sensitivity 0.91, CI 0.67-0.98; PPV 0.71, CI 0.58-0.80). Absolute and fixed modifications yielded similar results. Confidence intervals were wide, limiting generalizability. CONCLUSION: We could not identify modifications of non-pregnancy TSH and FT4 reference intervals that would enable centers to adequately approximate trimester-specific reference intervals. Future efforts should be turned towards studying the meaningfulness of trimester-specific reference intervals and risk-based decision limits.

Retrospective Cross-Sectional Study of the Relationship of Thyroid Volume and Function with Anthropometric Measurements, Body Composition Analysis Parameters, and the Diagnosis of Metabolic Syndrome in Euthyroid People Aged 18-65.

Background and Objectives: The thyroid is a key endocrine gland for the regulation of metabolic processes. A body composition analysis (BCA) is a valuable complement to the assessment of body mass index, which is derived only from body weight and height. This cross-sectional retrospective study aimed to investigate the relationships between thyroid volume (TV) and thyroid function parameters, anthropometric measurements, BCA parameters, and the presence of metabolic syndrome (MetS) in adults without clinically overt thyroid disease. Material and Methods: This study involved 45 people (females: 57.8%; MetS: 28.9%) hospitalized for planned diagnostics without signs of acute illness or a deterioration of their health and without thyroid disease, who underwent thyroid ultrasound scans, biochemical tests to assess their thyroid function, MetS assessments, anthropometric measurements, and BCAs using the bioelectrical impedance method. Results: The TV was significantly larger in people with MetS compared to people without MetS. The TV was significantly higher and the serum thyrotropin (TSH) concentration was significantly lower in overweight and obese people than in normal and underweight people. The free triiodothyronine (FT3) serum concentration and TV were correlated with waist circumference and some parameters of the BCA, and the FT3 concentration was also correlated with the body mass index, waist-hip ratio, and waist-height ratio. No significant correlations were found between the FT4 and TSH and the results of the anthropometric and BCA measurements. Conclusions: Even in a population of euthyroid patients without clinically overt thyroid disease, there were some significant relationships between the volume and function of the thyroid gland and the results of their anthropometric parameters, BCAs, and the presence of MetS features.

Suppressed thyroid stimulating hormone levels after initiation of a subcutaneous glucagon-like peptide-1 receptor agonist in a post-thyroidectomy patient managed with levothyroxine case report.

OBJECTIVES: Glucagon-like peptide-1 receptor agonist (GLP-1 RA) therapy has demonstrated an increased risk of thyroid C-cell hyperplasia and C-cell tumors in rodents. Due to this risk, a boxed warning for this drug class exists for people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. There is a lack of data regarding any possible effect of GLP-1 RA therapy on serum thyroid levels. The objective of this case report is to describe a case of suppressed thyroid stimulating hormone levels after initiation of a subcutaneous semaglutide in a post-total thyroidectomy patient managed with levothyroxine in order to highlight the need for closer monitoring of these patients and further research in this area. CASE SUMMARY: The patient described in the case underwent a total thyroidectomy in 2015 with stable thyroid hormone replacement requirements with levothyroxine for 5 years until the initiation and titration of subcutaneous semaglutide. The reduction in thyroid stimulating hormone (TSH) after starting GLP-1 RA therapy necessitated a 25 percent dose reduction of levothyroxine from her original dose. PRACTICE IMPLICATIONS: This patient experienced suppressed TSH levels following initiation and titration of subcutaneous semaglutide. The etiology of these changes may be related to the direct effects of GLP-1 RA therapy on TSH levels, changes in absorption related to delayed gastric emptying rates, secondary to GLP-1 RA-associated weight loss, or a combination of these proposed mechanisms. It may be prudent to exercise more frequent monitoring of medications that require weight-based dosing and those with a narrow therapeutic index when initiating and titrating GLP-1 RA-based therapies and is an area of potential study.

Effects of statin use on serum creatinine phosphokinase levels in normal thyroid function.

BACKGROUND/AIMS: Statins are common lipid-lowering agents used in dyslipidemia. However, they increase serum creatinine phosphokinase (CPK) levels. Currently, there are no studies on the effect of thyroid-stimulating hormone (TSH) levels on CPK levels after statin administration. Therefore, this study aimed to investigate CPK level alterations after statin administration according to TSH quartiles in participants with euthyroidism. METHODS: This retrospective analysis included 25,047 patients with euthyroidism. CPK levels were measured before and 6 months after statin administration. Normal TSH levels were divided into four quartiles, and the CPK levels and proportions of patients with normal CPK levels after statin administration for each TSH quartile were evaluated. RESULTS: The baseline CPK level was significantly higher in the lowest TSH quartile (Q1) compared to the other quartiles but decreased after statin administration. Thus, the difference between the CPK levels and the other quartile groups was not significant. The proportion of patients with normal CPK levels was also significantly lowest in Q1 before statin administration; however, no significant difference was noted in the ratio among each group after statin administration. These findings were consistent with the findings of the analysis according to statin intensity. CONCLUSION: In patients in the lowest TSH quartile of the normal TSH range, the CPK level decreased, and the proportion of normal CPK levels increased significantly after statin administration. However, similar changes were not observed in other TSH quartiles. Therefore, further studies are required to mechanistically confirm these conclusions.

Early identification of postoperative remission for thyrotropin-secreting adenomas.

OBJECTIVE: Thyrotropin-secreting adenoma (TSHoma) is a rare type of pituitary adenoma, occurring in one per million people. Little is known about TSHoma. We summarized the demographic, clinical and hormonal characteristics of TSHoma based on a single-centre experience. Moreover, we explored the predictive value of postoperative thyroid function for long-term remission. DESIGN, PATIENTS AND MEASUREMENTS: We retrospectively analysed 63 patients who were diagnosed as TSHoma and surgically treated at our hospital from January 2015 to June 2021. The preoperative clinical characteristics were analysed and compared between remission and nonremission groups. Thyroid function was measured at 1 day, 1 month, 3 months, 6 months, 12 months and over 12 months after surgery to determine whether they could predict long-term remission. RESULTS: The male to female ratio for TSHoma was 1.25. The mean age at diagnosis was 45 ± 12 years. Clinical presentation was varied, presenting with hyperthyroidism (68.25%), space-occupying effect (15.87%), amenorrhea (7.14% of female patients) and nonsymptoms (22.22%). 88.14% of patients achieved postoperative endocrinological remission. Larger tumour size and tumour invasion into cavernous sinus and suprasellar with chiasmal compression were strong predictors of lower rates of endocrinological remission. Postoperative thyroid function at 3 months was a viable diagnostic predictor for postoperative remission, especially for FT4 level with a 20.65 pmol/L cutoff. CONCLUSIONS: Tumour size and extent are major prognostic factors for remission. Postoperative thyroid function at 3 months could be used as a clinical prediction tool for long-term endocrinological remission.

Dynamic Risk Model for the Medical Treatment of Graves' Hyperthyroidism according to Treatment Duration.

BACKGRUOUND: Changes in thyrotropin receptor antibody (TRAb) levels are associated with the clinical outcomes of Graves' hyperthyroidism. However, the effects of the patterns of TRAb changes on patient prognosis according to the treatment duration of antithyroid drugs (ATDs) are not well established. METHODS: In this retrospective cohort study, 1,235 patients with Graves' hyperthyroidism who were treated with ATDs for more than 12 months were included. Patients were divided into two groups according to treatment duration: group 1 (12-24 months) and group 2 (>24 months). Risk prediction models comprising age, sex, and either TRAb levels at ATD withdrawal (model A) or patterns of TRAb changes (model B) were compared. RESULTS: The median treatment duration in groups 1 (n=667, 54%) and 2 (n=568, 46%) was 17.3 and 37.1 months, respectively. The recurrence rate was significantly higher in group 2 (47.9%) than in group 1 (41.4%, P=0.025). Group 2 had significantly more goiter, thyroid eye disease, and fluctuating and smoldering type of TRAb pattern compared with group 1 (all P<0.001). The patterns of TRAb changes were an independent risk factor for recurrence after adjusting for other confounding factors in all patients, except in group 1. Integrated discrimination improvement and net reclassification improvement analyses showed that model B performed better than model A in all patients, except in group 1. CONCLUSION: The dynamic risk model, including the patterns of TRAb changes, was more suitable for predicting prognosis in patients with Graves' hyperthyroidism who underwent longer ATD treatment duration.

Hypothyroidism Presenting Atypically as an Isolated Pericardial and Pleural Effusion: A Case Report.

Hypothyroidism is an endocrine disorder characterized by low thyroid hormone levels, which commonly presents as fatigue, cold intolerance, constipation, poor memory and/or concentration, and weight gain. Common signs of hypothyroidism include bradycardia, electrocardiograph changes, a lower basal temperature, a slower relaxation phase of deep tendon reflexes, and swelling of the extremities. Hypothyroidism is diagnosed with labs showing high thyroid-stimulating hormone levels and low free thyroxine. Hypothyroidism may present as a pericardial or pleural effusion, with the incidence of each being unknown. The paucity of information regarding the incidence of pericardial and pleural effusions in hypothyroidism may be due to effusions being an atypical complication of a common endocrine disorder. Hypothyroidism, including in cases of pericardial or pleural effusions, is typically treated with thyroid hormone replacement therapy, usually in the form of levothyroxine. Hemodynamic compromise may necessitate pericardiocentesis or pleurocentesis. In this case report, we present an atypical presentation of hypothyroidism that is characterized by an isolated pericardial and pleural effusion in a patient with post-thyroidectomy hypothyroidism who was non-adherent to levothyroxine. We discuss the pathophysiology of pleural and pericardial effusions in thyroid disease, which is thought to involve increased capillary permeability and changes in oncotic pressure related to albumin. We also review treatment strategies regarding pericardial and pleural effusions in hypothyroidism.

Thyroid-related Hormones and Hypertension Incidence in Middle-Aged and Older Hispanic/Latino Adults: The HCHS/SOL Study.

Background: Thyroid-related hormones act to regulate metabolic pathways and blood pressure (BP). However, the relationship of TSH and peripheral thyroid hormones and the role of the hypothalamic-pituitary-thyroid axis on hypertension development is not fully understood. We assessed sex-specific associations of thyroid-related hormones with BP and hypertension in Hispanic/Latino adults followed for 6 years. Methods: We studied 1789 adults, ages 45 to 74, free of diabetes at baseline from a subcohort of the Hispanic Community Health Study/Study of Latinos. We assessed TSH, free T4 (FT4), T3, and various indicators of thyroid axis. Using multivariable linear and Poisson regression adjusted for survey design and confounding variables, we estimated a priori sex-specific associations of thyroid-related hormones with changes in BP and hypertension development. Results: In men and women, TSH and TSH/FT4 ratios were associated with changes in diastolic BP and T3 with changes in pulse pressure and the development of hypertension from prehypertension. In men, a 1-SD increase in TSH [incident rate ratio (IRR) = 1.42; 95% confidence interval (CI): 1.15, 1.75] and TSH/FT4 ratio (IRR = 1.20; 95% CI: 1.07, 1.35) were positively associated with the development of hypertension from prehypertension while the TSH/FT4 ratio (IRR = 0.85; 95% CI: .72, 1.00) was protective in women. We observed sex-specific differences in associations of the T3/FT4 ratio and indices of pituitary sensitivity to thyroid hormones with changes in pulse pressure and hypertension development. Conclusion: Thyroid-related hormones are associated with sex-specific changes in BP and hypertension among Hispanic/Latino adults consistent with selected studies conducted in other populations. Mechanisms underlying associations of pituitary sensitivity to thyroid hormones with BP and hypertension development warrant further study.