Diagnosis Of Subclinical Hypothyroidism Research Articles

Application of composite reference intervals in the diagnosis of subclinical hypothyroidism in the elderly: a retrospective study.

Thyroid stimulating hormone releasing hormone (TSH) is a key indicator for diagnosing subclinical hypothyroidism (SCH). We evaluated factors affecting TSH levels in elderly SCH, establishing a composite reference interval, and comparing it with traditional one in diagnosis. We collected data on patients aged ≥60 undergoing physical examinations in Chengdu, screening the influencing factors associated with TSH. Then, a two-dimensional composite reference interval was established for TSH and FT4, and the differences between the new and traditional diagnosing methods were compared. The incidence of subclinical thyroid dysfunction was about 14%, with SCH accounting for 97%. Regression analysis found that TSH levels increase as FT4 and uric acid levels decrease. Compared with the two-dimensional composite reference interval, the traditional one has a higher incidence rate of SCH. Compared with the two-dimensional composite reference interval, the traditional one is more likely to overestimate the incidence rate of SCH, leading to excessive diagnosis and treatment.

Patient education about subclinical hypothyroidism in preconception and early pregnancy

Introduction: The diagnosis and treatment of Subclinical Hypothyroidism (SCH) in preconception and early pregnancy has been an area of debate. The challenge of managing SCH further lies in often suboptimal patient understanding of the condition given its asymptomatic state. This study aimed to assess whether patient education materials could improve patient knowledge about SCH and encourage compliance with clinical management. Furthermore, we reviewed the current recommendations for the diagnosis and treatment of SCH in preconception and pregnancy. Methods: Patients who presented to the Reproductive Medicine and Infertility Clinic, Augusta University, Georgia, USA between July 2023 and February 2024, who were attempting to conceive or in early pregnancy, and who met the SCH diagnostic criteria were invited to participate in this prospective cohort study. The study participants completed a pre-education and demographic questionnaire, underwent a brief consultation with a provider who reviewed the SCH information sheet, and then completed the post-education questions. Paired Wilcoxon rank-sum tests of significance were used to evaluate the change in pre- and post-education scores. Results: Thirteen patients completed the survey. There was a range of pre-existing knowledge about SCH in our study population. Most patients acquired knowledge about SCH diagnosis (Q1: P = 0.013) during the counseling. Patient education improved their attitudes about the treatment of SCH with levothyroxine (Q3: P = 0.029). Conclusion: While the clinical guidelines on diagnosis and treatment of SCH in preconception and early pregnancy continue to evolve as more research becomes available, patient education can significantly improve their knowledge about the condition and encourage compliance with treatment if indicated.

Comparison of fasting versus postprandial thyroid function test and growth hormone status in known subclinical hypothyroid patients based on hormonal changes in medical college and hospital, Kolkata

Background: Thyroxine (T4) and triiodothyronine are the main thyroid hormones that play an essential role in cellular metabolism, growth, and tissue development, and subclinical hypothyroidism (SCH) is often defined by a thyroid-stimulating hormone (TSH) level above the upper limit of the reference range (usually around 4.0 or 4.5 mIU/L, usually TSH level in between 4 and 10 mIU/mL) along with a normal free T4 (fT4) level. Previous studies undertaken in various parts of the world have shown food intake can influence the TSH level at different percentages and these studies speculated that if we measure TSH level 2 h after breakfast (9:00 am) compared with the fasting blood samples that is generally collected in the morning (7:00 am), the TSH level is significantly reduced by about 30%, and this significant difference created reasonable doubt in the diagnosis of SCH. Aims and Objectives: The study aimed to evaluate the difference in serum TSH, fT4, leptin, cortisol, insulin, adiponectin, and glucagon-like peptide-1 (GLP-1) between fasting and post-prandial blood samples in known subclinical hypothyroid patients. Materials and Methods: This descriptive, cross-sectional, non-interventional study was done on 50 diagnosed subclinical hypothyroid patients after screening them through the inclusion–exclusion criteria. The estimations were done by chemiluminescence immunoassay or enzyme-linked immunosorbent assay method, statistical analysis was done using Statistical Packages for the Social Sciences. Results: After analysis of blood samples, it showed that the serum TSH decreased progressively after food intake for almost 2 h, the level of decrease is statistically significant (from 7.38 ± 1.22 mIU/mL to 5.9 ± 1.03 mIU/mL) (P < 0.001). Serum fT4 level remained almost unchanged after food intake. Conclusion: As per previous and our study a possible explanation of this post-prandial fall of TSH can be that food consumption causes an alteration in circulating glucose levels, insulin, leptin, gastric inhibitory polypeptide (cholecystokinin and GLP-1), and cortisol. Growth hormone (GH) and somatostatin levels also suppress TSH secretion from the pituitary. As both over- and under-treatment with eltroxin can be detrimental for subclinical hypothyroid children and pregnant women, so further studies with larger sample sizes and somatostatin and GH estimation should be done to authenticate the findings of this study.

Comparison of gastric emptying before and after treatment for subclinical hypothyroidism

Aim: The aim of this study was to evaluate the effect of levothyroxine treatment on dyspeptic symptoms and gastric emptying time in patients with subclinical hypothyroidism. Materials and Methods: Liquid gastric emptying scintigraphy was performed to detect the presence of gastroparesis in patients with dyspeptic complaints who were followed up with a diagnosis of subclinical hypothyroidism in the thyroid outpatient clinic. Those with specific hypothyroidism symptoms during their follow-up were treated with low dose (25 mg) levothyroxine for at least 6 months. Liquid gastric emptying scintigraphy test was performed again after treatment for those who continued to have dyspeptic complaints. Patients whose gastric emptying time was calculated using a liquid gastric emptying scintigraphy test before and after levothyroxine treatment were retrospectively examined. For testing, 18.5-37 MBq (0.5-1 mCi) 99m-TC nanocolloid was added to 300 ml of water. Late images were acquired at 30 minutes and one hour. The time activity curve was obtained. Results: Gastric emptying was normal in 13 (23.6%) patients in the liquid gastric emptying scintigraphy test performed before treatment. After treatment, gastric emptying half-time was normalized in 34 (81%) of 42 (76.4%) patients with a long gastric emptying half-time before treatment. In total, 47 patients had normal gastric emptying half-time values after treatment, and gastric emptying half-time was calculated to be long in 8 patients (14.5%). Conclusion: In our study, gastric emptying time was prolonged in 76.4% of patients with subclinical hypothyroidism, and in 81% of these patients, gastric emptying time was calculated within normal limits after LT4 treatment. Detection of prolongation of gastric emptying time due to the presence of gastroparesis in subclinical hypothyroidism cases followed up without treatment may be a guide in the prescription of treatment.

A comparative study on outcomes of fasting vs postprandial thyroid function tests among pregnant mothers in a tertiary care setting in Sri Lanka.

Accurate estimation of serum thyrotropin (TSH) is crucial in the diagnosis of subclinical hypothyroidism (SCH) in pregnancy. We aimed to investigate whether there are significant differences between fasting and nonfasting thyroid function tests (TFTs) among pregnant mothers. We studied 100 pregnant mothers with previously unknown thyroid dysfunction. An equal number of participants were included in each trimester. All pregnant mothers underwent fasting and 2-hour postprandial TFTs (TSH, free T4). Postprandial TSH (mean 1.01 mIU/L, SD 0.80) was significantly lower than the fasting TSH (mean 1.47 mIU/L, SD 1.18) in pregnancy (P < .01). Postprandial free T4 (mean 10.30 pmol/L, SD 2.01) was also lowered compared with fasting free T4 (mean 10.70 pmol/L, SD 1.99) in pregnancy (P < .01). The prevalence of SCH in pregnancy estimated using fasting TSH was 9.4% (SD 3%). In contrast, the prevalence was only 3.5% (SD 2%) when postprandial TSH was used. Compared with the fasting state, postprandial TSH demonstrates a statistically significant reduction that greatly influences the diagnosis of SCH in pregnant mothers. Therefore, we conclude that the timing of sampling for TFTs should be standardized, especially in the pregnant population.

Focusing on the Critical Role of Age and Sex in the Diagnosis of Subclinical Hypothyroidism and Associated Levothyroxine Prescription.

Focusing on the Critical Role of Age and Sex in the Diagnosis of Subclinical Hypothyroidism and Associated Levothyroxine Prescription.

Subclinical Hypothyroidism Diagnosis and Management in Primary Care settings

Subclinical hypothyroidism is a prevalent thyroid disorder characterized by elevated thyroid-stimulating hormone (TSH) levels and normal free thyroxine (T4) levels. Its diagnosis and management in primary care settings present ongoing challenges and uncertainties. This systematic review aims to evaluate the current evidence regarding the diagnosis and management of subclinical hypothyroidism in primary care, with a focus on diagnostic criteria, clinical outcomes, and treatment approaches. A comprehensive search of electronic databases (PubMed, Embase, Cochrane Library) was conducted to identify relevant studies published in English within the last 10 years. Randomized controlled trials, cohort studies, and systematic reviews were included. Study selection, data extraction, and quality assessment were performed by two independent reviewers. The findings were synthesized descriptively, and meta-analysis was conducted when appropriate. A total of 25 studies met the inclusion criteria and were included in this review. Diagnostic criteria for subclinical hypothyroidism varied across the studies, with differing TSH thresholds used to define the condition. The clinical outcomes associated with subclinical hypothyroidism were heterogeneous, including cardiovascular risks, metabolic disorders, and quality of life. The management of subclinical hypothyroidism in primary care was diverse, ranging from watchful waiting to levothyroxine therapy. The benefits of levothyroxine treatment were inconclusive, with some studies reporting improvement in symptoms and lipid profiles, while others found no significant differences compared to placebo or observation. The diagnosis and management of subclinical hypothyroidism in primary care remain controversial. The variability in diagnostic criteria and inconsistent evidence on clinical outcomes and treatment efficacy complicate decision-making. Future research should focus on establishing standardized diagnostic thresholds, evaluating ....

The relationship between the two endocrine pathologies: subclinical gestational hypothyroidism and gestational diabetes mellitus

BACKGROUND: Over the past decade, gestational diabetes mellitus has become of increasing medical and social importance. It happens due to its increased prevalence and due to its negative impact on pregnancy and long-term metabolic disorders in the mother and fetus.&#x0D; AIM: The aim of this study was to assess the relationship between subclinical gestational hypothyroidism and gestational diabetes mellitus, the two most common endocrine pathologies in pregnancy.&#x0D; MATERIALS AND METHODS: We studied 200 medical records of pregnant women. The main group included 133 patients with subclinical gestational hypothyroidism, and the control group consisted of 67 women without endocrine pathology. The diagnosis of gestational diabetes mellitus was made based on the Ministry of Health of the Russian Federation clinical guidelines criteria. The diagnosis of subclinical hypothyroidism was made based on the thyroid-stimulating hormone level above 2.5 IU/ml in combination with an increased titer of antithyroid antibodies or above 4.0 IU/ml in the absence of any thyroid disorder. Statistical analysis was carried out using the StatTech v.2.1.0 program (Stattech Ltd, Russia).&#x0D; RESULTS: The prevalence of hypothyroidism was higher among women with family history of diabetes mellitus. The chances of developing gestational diabetes mellitus increased by 9.706 times in the presence of hypothyroidism, by 1.077 times with an increase in age by one full year at the time of seeing the doctor, and by 1.023 times with an increase in weight before pregnancy by one kilogram. The thyroid-stimulating hormone level of more than 2.7 IU/ml predicted the development of gestational diabetes mellitus with a sensitivity of 71.4% and a specificity of 63.1%.&#x0D; CONCLUSIONS: Subclinical gestational hypothyroidism and gestational diabetes mellitus are interrelated endocrine disorders with common pathophysiological predictors. Among women with a normal body mass index, subclinical gestational hypothyroidism is a more significant risk factor for gestational diabetes mellitus than an increase in age or body weight. A certain threshold level of thyroid-stimulating hormone (more than 2.7 IU/ml) in the first trimester increases the chances of developing gestational diabetes mellitus and should be considered as a signal for timely prevention and detection of gestational diabetes mellitus.

Study of Lipid Parameters in Subclinical Hypothyroidism

Introduction: The Diagnosis of subclinical hypothyroidism is mostly biochemical as most of the patients have aserum TSH above the normal and serum free and total T4 and T3 are normal. Due to recent increasing prevalenceof sub-clinical hypothyroidism and metabolic risk factors such as adverse cardiac function and hyperlipidemia, itrecommended the importance of screening by assessment of serum TSH.Aims: To assess the lipid profile in patients diagnosed with sub-clinical hypothyroidismMethods and Materials: This study is a hospital based cross sectional study and comprised a total of 96 subjectsperformed in Chalmeda Anandrao Institute of Medical Sciences. Patients presenting to OPD with vague complaintsof hypothyroidism are selected. They are screened for subclinical hypothyroidism by doing fasting TFT comprisingfreeT4, freeT3 and TSH and fasting lipid profile is also done for the patient. Laboratory analysis of blood urea,serum creatinine done.Results: A Total number of 96 patients were studied, majority of them were between age group of 46 to 55 years.The BMI distribution among SCH has no correlation to serum TSH levels.Prevalence of subclinical hypothyroidism is more common among women.TSH values range from minimum of 5.8 mIU/l to maximum of 25mIU/l.Hypercholesterolemia was found in 40.6% of patients. LDL was elevated in 42.7% of cases. Triglyceride waselevated in only 27.1%. HDL values were found to be normal in 66.7% of cases.Conclusion: Our study concludes that there are significant elevations in total cholesterol and serum LDL insubclinical hypothyroidism. There is no much significant changes in triglycerides and HDL levels.

The Relationship Between Subclinical Hypothyroidism and Gestational Diabetes Mellitus

The most common metabolic disorder during pregnancy is gestational diabetes mellitus (GDM). GDM can occur in anywhere between 1.7 and 11.6 percent of people. In hypothyroidism, the rates of glucose oxidation and glycogen synthesis are reduced, and the peripheral tissues' consumption of glucose is also delayed. Patients with subclinical and overt hypothyroidism develop insulin resistance because insulin is unable to adequately maintain the muscles' use of glucose. According to the literature, hypothyroidism is linked to 6–15 percent of GDM pregnancies. Additionally, the chance of having GDM is 4.3 times higher in pregnant women who have hypothyroidism. This study aimed to reveal the relationship between first-trimester thyroid function tests and GDM. This retrospective cohort study was conducted between May 2021 and May 2022. 100 pregnant patients diagnosed with GDM and 500 healthy controls were included in the study. Using a 75 g glucose challenge test, GDM was identified. The trimester-specific recognized normal limits were used to evaluate the TSH and fT4 readings. There was a statistically significant difference in terms of SCH between patients with and without GDM (p=0.04). TSH's performance in predicting GDM was evaluated using AUC and ROC (AUC=0.586 and p=0.006). To forecast GDM, the TSH level cut-off value was discovered to be 1.58. The AUC was found to be 0.586 (0.521-0.652). Furthermore, the selectivity is 58% and the sensitivity is 41%. There are many studies in the literature investigating thyroid functions and the development of gestational diabetes mellitus. Our study also found a correlation between the diagnosis of subclinical hypothyroidism in the first trimester and GDM. The study adds to the literature the importance of being cautious and vigilant in terms of the development of gestational diabetes mellitus based on the results of the thyroid function test in the first trimester.

Subklinik Hipotiroidizm ile Gestasyonel Diabetes Mellitus Arasındaki İlişki

Aim: The most common metabolic disorder during pregnancy is gestational diabetes mellitus (GDM). GDM can occur in anywhere between 1.7 and 11.6 percent of people. In hypothyroidism, the rates of glucose oxidation and glycogen synthesis are reduced, and the peripheral tissues' consumption of glucose is also delayed. Patients with subclinical and overt hypothyroidism develop insulin resistance because insulin is unable to adequately maintain the muscles' use of glucose. According to the literature, hypothyroidism is linked to 6–15 percent of GDM pregnancies. Additionally, the chance of having GDM is 4.3 times higher in pregnant women who have hypothyroidism. This study aimed to reveal the relationship between first-trimester thyroid function tests and GDM. &#x0D; Material and Method: This retrospective cohort study was conducted between May 2021 and May 2022. 100 pregnant patients diagnosed with GDM and 500 healthy controls were included in the study. Using a 75 g glucose challenge test, GDM was identified. The trimester-specific recognized normal limits were used to evaluate the TSH and fT4 readings.&#x0D; Results: There was a statistically significant difference in terms of SCH between patients with and without GDM (p=0.04). TSH's performance in predicting GDM was evaluated using AUC and ROC (AUC=0.586 and p=0.006). To forecast GDM, the TSH level cut-off value was discovered to be 1.58. The AUC was found to be 0.586 (0.521-0.652). Furthermore, the selectivity is 58% and the sensitivity is 41%&#x0D; Conclusion: There are many studies in the literature investigating thyroid functions and the development of gestational diabetes mellitus. Our study also found a correlation between the diagnosis of subclinical hypothyroidism in the first trimester and GDM. The study adds to the literature the importance of being cautious and vigilant in terms of the development of gestational diabetes mellitus based on the results of the thyroid function test in the first trimester.

Investigation of the frequency of obstructive sleep apnoea syndrome in patients with subclinical hypothyroidism.

BackgroundThe aim of this study is to determine the frequency of obstructive sleep apnoea syndrome (OSAS) in a study group with the diagnosis of subclinical hypothyroidism and in a control group without the diagnosis of subclinical hypothyroidism. This study compares these two groups in terms of demographic characteristics, chronic diseases and especially polysomnographic data.MethodsA total of 120 patients were included in this study. They consisted of 60 patients with newly diagnosed subclinical hypothyroidism and a control group of 60 patients with normal thyroid functions. Demographic, anthropometric, polysomnography data and Epworth Sleepiness Scale scores of the patients were recorded and compared.ResultsAny significant difference in the frequency and severity of OSAS was not detected. A significant difference was found in the oxygen desaturation index (ODI), the apnoea–hypopnoea index (AHI) in rapid eye movement sleep, the AHI in supine sleep position and the arousal index of the group experiencing subclinical hypothyroidism with OSAS.ConclusionThis study showed that there was no increase in OSAS frequency in patients with subclinical hypothyroidism, but it demonstrated that the ODI and the arousal index were significantly increased in OSAS patients diagnosed with subclinical hypothyroidism. It is thought that the diagnosis and treatment of OSAS in these patients may be important in preventing cardiovascular complications.

Association of Subclinical Hypothyroidism with Present and Absent Anti-Thyroid Antibodies with PCOS Phenotypes and Metabolic Profile.

Background: Polycystic ovary syndrome (PCOS) and subclinical hypothyroidism (SCH) often coexist, but implications of the co-occurrence of two disorders have not yet been established. The objective is to conclude whether SCH with present or absent anti-thyroid antibodies (ATA) impacts on the PCOS phenotype and alters biochemical or clinical parameters. Methods: A retrospective cohort study was conducted in a tertiary reference center. Clinical and biochemical parameters of women with PCOS were analyzed. Results: A total of 367 women with PCOS were included in the study, 114 (31.1%) of whom were diagnosed with SCH and 16 (4.4%) with autoimmune thyroiditis (AIT). Among all parameters studied, the strongest relationship with SCH was confirmed for insulin resistance and dyslipidemia. SCH was an independent risk factor for insulin resistance. In SCH the additional presence of ATA did not exacerbate the metabolic disorders. There was no significant association of any PCOS phenotype with SCH, nor with the presence of circulating ATA. There was no significant difference in hormonal parameters and mFerriman–Gallwey scale score between women with PCOS with and without SCH. Conclusions: SCH alters metabolic, but not hormonal, parameters in PCOS. The diagnosis of SCH does not exclude the diagnosis of PCOS. The potential effect of positive ATA was insignificant.

Subclinical hypothyroidism

Subclinical hypothyroidism is usually a laboratory diagnosis without significant symptoms and is defined by an elevated thyroid-stimulating hormone (thyrotropin, TSH) with normal thyroid hormone levels. On laboratory checks after two to three months, spontaneous normalization is found in 50 % of all cases in the sense of a transient elevation.With persistently elevated TSH levels, subclinical hypothyroidism is associated with evidence of thyroid-specific antibodies in the sense of autoimmune thyroiditis. Physiologically higher TSH levels are found in old age. It can therefore be assumed that the diagnosis of subclinical hypothyroidism is made and treated too frequently in older people over 70years of age.Studies have so far failed to show a positive effect of substitution therapy of subclinical hypothyroidism, especially in elderly patients. On the other hand, there is a not inconsiderable risk of overtreatment with the development of subclinical hyperthyroidism. Its negative consequences in the form of atrial fibrillation and osteoporosis impair the quality and duration of life. Therefore, the indication for substitution therapy of subclinical hypothyroidism should be made with caution.One group in which diagnosis and therapy require special sensitivity is pregnant women. Here, two individuals, mother and child, must be treated. Varying target values and dosages in relation to the gestational age must be taken into account.

Treating hypothyroidism is not always easy: When to treat subclinical hypothyroidism, TSH goals in the elderly, and alternatives to levothyroxine monotherapy.

The majority of patients with hypothyroidism feel better when levothyroxine treatment restores thyroid-stimulating hormone (TSH) concentrations to normal. Increasingly, a significant minority of patients remain symptomatic and are dissatisfied with their treatment. Overzealous treatment of symptomatic patients with subclinical hypothyroidism may contribute to dissatisfaction among hypothyroidism patients, as potential hypothyroid symptoms in patients with minimal hypothyroidism rarely respond to treatment. Thyroid hormone prescriptions have increased by 30% in the United States in the last decade. The diagnosis of subclinical hypothyroidism should be confirmed by repeat thyroid function tests ideally obtained at least 2months later, as 62% of elevated TSH levels may revert to normal spontaneously. Generally, treatment is not necessary unless the TSH exceeds 7.0-10mIU/L. In double-blinded randomized controlled trials, treatment does not improve symptoms or cognitive function if the TSH is less than 10mIU/L. While cardiovascular events may be reduced in patients under age 65 with subclinical hypothyroidism who are treated with levothyroxine, treatment may be harmful in elderly patients with subclinical hypothyroidism. TSH goals are age dependent, with a 97.5percentile (upper limit of normal) of 3.6mIU/L for patients under age 40, and 7.5mIU/L for patients over age 80. In some hypothyroid patients who are dissatisfied with treatment, especially those with a polymorphism in type 2 deiodinase, combined treatment with levothyroxine and liothyronine may be preferred.

The role of serum thyroid stimulating hormone reference interval in the diagnosis of subclinical hypothyroidism and its influencing factors

亚临床甲状腺功能减退症（甲减）是最常见的甲状腺功能异常，血清促甲状腺激素（TSH）是诊断亚临床甲减的关键指标。TSH参考范围不统一是既往亚临床甲减患病率差异较大的主要原因。目前推荐采用美国国家临床生物化学学会（NACB）标准选择参考人群，用经对数转换后的2.5%~97.5%可信区间确定TSH参考范围。但是，我们还应充分考虑个体内和个体间因素对TSH参考范围的影响，在试剂盒参考范围的基础上，结合上述因素，分析患者血清TSH升高的原因，才能对亚临床甲减做出合理的诊断和干预。.

Assessment of serum cortisol and thyrotropin correlation in euthyroid and subclinical hypothyroid subjects

ABSTRACT Background: The upper limit of the normal range for TSH concentration, used to diagnose subclinical hypothyroidism, is controversial. This study was conducted to examine the association of cortisol and thyrotropin in subjects with TSH<10 mIU/L. Research design and methods This cross-sectional study was performed on healthy volunteers and those who had been referred with a diagnosis of subclinical hypothyroidism (TSH<10 mIU/L). Subjects with the age of 18-35 years were enrolled. The sera were analyzed for Cortisol, FT4, FT3, TSH, Ani-TPO, and Anti-Tg. Results Final sample of 36 in group A (TSH<2.5), 45 in group B (TSH: 2.5–4.2), and 71 in group C (TSH: 4.3–10) were included. Cortisol levels were significantly different in the three groups, the lowest for the A group and higher for the C group, and the two-to-two difference in the groups was also significant (p < 0.001). There was a positive and significant correlation between cortisol levels with TSH (r = 0.740; p < 0.001). Conclusion There was a potential link between TSH and serum cortisol in young people so that with an increase in TSH from 2.5, the serum cortisol level also increases, but this positive correlation in TSH ≤2.5 was not observed.

Use of levothyroxine among pregnant women with subclinical hypothyroidism in the United Kingdom: A population-based assessment.

Our study aimed to describe levothyroxine prescription patterns and trends over time among pregnant women with subclinical hypothyroidism (SCH) in the United Kingdom.We used data from the Clinical Practice Research Datalink linked to its Pregnancy Register and the Hospital Episode Statistics database from 1998 to 2017. The study population included women with a diagnosis of SCH or an abnormal thyroid‐simulated hormone (TSH) level one year prior to or during pregnancy. We compared characteristics between women who received a prescription for levothyroxine during pregnancy and those who did not. We further described the timing, dose, duration, and temporal trends of levothyroxine prescriptions.Our cohort included 6,757 pregnancies from 6,287 women with SCH, of whom 10% received levothyroxine during pregnancy. Among women who received levothyroxine, most received their first prescription during the first trimester (median gestational age: 7 weeks; interquartile range [IQR]: 0, 16) with a median daily dosage of 50 mcg (IQR: 50, 73). Levothyroxine prescription varied over time, decreasing from 23% of pregnant women in 1998 to 7.5% in 2003, remaining stable until 2014, and increasing to 12.5% in 2016. Smoking, diabetes, polycystic ovary syndrome, infertility, timing of SCH diagnosis, age, TSH level at diagnosis, and general practice regions were associated with prescription.Few women with SCH received levothyroxine during pregnancy, and treatment varied by patient characteristics and geographical regions. These results highlight the need to increase awareness among healthcare providers and will guide future studies that explore barriers to initiating levothyroxine treatment for women with SCH during pregnancy.

Subclinical Hypothyroidism Affects Postoperative Outcome of Patients Undergoing Total Knee Arthroplasty.

ObjectiveThe aim of this study was to investigate whether subclinical hypothyroidism could increase the risk of postoperative complications in patients undergoing primary total knee arthroplasty (TKA).MethodsA prospective case‐control study of 796 patients undergoing primary TKA between January 2015 and January 2020 was performed. A total of 700 patients (87.9%) were female and the average age of included patients was 65.0 years, with a standard deviation of 5.6. The participants who had subclinical hypothyroidism were referred to as the case group, while those without abnormal thyrotropin (TSH) were included in the control group (matched for age and gender). The fasting plasma levels of TSH were tested in the morning in all patients. The diagnosis of subclinical hypothyroidism was completed by a senior endocrinologist based on laboratory tests; namely, a serum TSH ≥ 5 mu/L and normal free thyroxine (FT4). Subclinical hypothyroidism was further described as mild (TSH < 10 mu/L) or severe (TSH ≥ 10 mu/L). The incidence of 90‐day postoperative complications was compared between two cohorts. Logistic regression analysis was used for the risk factors of 90‐day postoperative complications following TKA.ResultsA total of 398 patients had a diagnosis of subclinical hypothyroidism. Among them, 275 cases (69.1%) were described as mild (79 patients [19.8%] with low FT4 and 196 patients [49.2%] with normal FT4 in the repeated test) and 123 cases (30.9%) as severe subclinical hypothyroidism. Of the 196 patients (49.2%) with mild subclinical hypothyroidism and normal FT4, 63 patients (15.8%) had symptoms before surgery. Patients were followed up for an average duration of 25.4 months (6 to 43 months). A total of 265 patients (66.6%) received preoperative treatment for subclinical hypothyroidism, with an average therapy time of 9.2 months. There were 162 patients (40.7%) with positive autoantibodies to thyroid peroxidase (anti‐TPO). There were no statistically significant differences in baseline data between cohorts (all P > 0.05). As for the cumulative 90‐day outcomes, subclinical hypothyroidism increased the incidences of both medical and surgical complications following primary TKA compared to those without this condition (11.6% vs 7.2%, OR = 1.55, 95% confidence interval [CI] = 1.47–1.62, P < 0.05). Subclinical hypothyroidism caused patients to suffer increased total incidence of readmission within the first 90 days after discharge when compared to those without this condition (20.61% vs 14.15%, OR = 1.45, 95% CI = 1.41–1.49, P < 0.001). Controlling for preoperative and intraoperative variables, the patients with TSH ≥ 10 mu/L and positive anti‐TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation were more likely to experience postoperative complications within 90 days of TKA.ConclusionSubclinical hypothyroidism might increase the risk of postoperative complications within 90 days of TKA, especially for the patients with TSH ≥ 10 mu/L and positive anti‐TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation.

Screening determination of thyroid stimulating hormone in diagnosis of subclinical hypothyroidism in pregnant women: versions and contraversions

The work is devoted to the necessity of conducting a screening study of thyroid function in women in the pre-gravidar period and during gestation. Pathological conditions of the thyroid gland are one of the most common diseases of the endocrine system, second only to diabetes mellitus in prevalence. At the same time, in recent years, there has been an increase in thyroid insufficiency. Clinical and subclinical hypothyroidism are the most common hormonal dysfunctions during pregnancy, which have a negative impact on the course of gestation and fetal development. At the same time, subclinical hypothyroidism is an easily treatable disease that reduces the pregnancy related morbidity of the mother and fetus. Screening only at-risk patients probably skips most cases. Therefore, guidelines should be established for universal screening of thyroid dysfunction in the pre-gravidar period and during pregnancy with their own ranges for thyroid stimulating hormone during gestation, calculated taking into account regional, ethnic and population characteristics. Levothyroxine replacement therapy in a woman with subclinical hypothyroidism in the pre-gravidar period and during pregnancy should begin immediately after the diagnosis of this condition and be adequate in terms of timing and dose.