Serum Free T4 Levels Research Articles

Nonthyroidal illness syndrome as marker of severity in pediatric high dependency units: A single-center prospective cross-sectional observation study from Brazil

Background: Limited data is available in children with nonthyroidal illness syndrome (NTIS) and its association with prognosis in acute illness. This study was conducted to compare thyroid function as marker of severity with pediatric risk of mortality (PRISM) and pediatric index of mortality (PIM) in pediatric high dependency unit (PHDU).Subjects and Methods: This was a prospective, cross-sectional observational study of 225 patients, aged 1–14 years with respiratory symptoms, admitted to a PHDU in a secondary care hospital in Brazil. PRISM-IV and PIM-2 scores were calculated and serum thyroid-stimulating hormone (TSH), free T4, T3, and T4 levels were measured on admission. The presence of NTIS was considered in patients with total T3 below reference values, which may be associated with normal or low levels of total T4.Results: The mean age of the study population was 52.9 ± 35.9 months; Male-to-female ratio is was 1.2. All patients had normal free T4 levels. In 65.9% of cases, TSH remained within normal limits, while 34.1% were below the reference range for age. The prevalence of NTIS was 45.8%. Total T3 was normal in 54.2% and total T4 was normal in 90.2% of cases. Low total T3 with normal total T4 was found in 36% of patients while both total T3 and T4 were low in 9.8% of cases. Lower PRISM IV scores (P = 0.0014) and lower PIM-2 scores (P < 0.0001) were significantly correlated with absence of NTIS.Conclusions: Patients without evidence of NTIS have lower disease severity scores and a better prognosis.

Prevalence of Hypothyroidism in PCOS in Jharkhand

Polycystic ovarian syndrome and thyroid disorders are common endocrine disorders in females worldwide. These two problems are having many common features but are with very different etiopathogenesis. The increase in ovarian volume and cystic changes in ovaries have been reported in primary hypothyroidism due to disturbed ratio of FSH and LH. It is also seen that thyroid disorders are more common in women with PCOS as compared to the normal population may be due to other associated factors like insulin resistance, increased androgen secretion and obesity. There might be some common factors in individuals predisposing to both disorders but till date not any common pathophysiology is established between these two. The increased ovarian volume and fertility improves by administration of thyroxin apart from that it helps to control obesity and to some extent obesity related disorders. The diagnosis of hypothyroidism during adolescence will be helpful to improve especially fertility and PCOS related clinical conditions. The thyroid function study was done in PCOS patients between 18 to 35 years of age residing in Jharkhand and the results were compared with age matched healthy women. Having no medical problem or on contraceptive steroids females. Serum fasting free t3,free t4 and TSH levels were estimated. PCOS was confirmed by USG. Results of present study shows the prevalence of hypothyroidism in PCOS patient in Jharkhand.

Frequency of subclinical hypothyroidism and mean serum TSH level in first trimester of pregnancy.

Objective: To find out the frequency of subclinical hypothyroidism (SCH) in our pregnant population during 1st Trimester and the mean TSH level in first trimester of pregnancy. Study Design: Cross Sectional Descriptive study. Setting: Dow University Hospital and Dr Ruth KM Pfau CHK. Period: June 2015 to May 2016. Material &amp; Methods: All Pregnant women with &lt;14 weeks gestation were screened for Serum TSH level. Data were recorded after informed consent and institutional ethical approval. Variables recorded were age, parity, gestational age and serum TSH level. Data were analyzed on SPSS version 16. Mean and SD were calculated for quantitative variables ie. Age, parity, gestational age, serum TSH level and serum free T4 level. Mean TSH level according to age group, parity and gestational age groups were determined by applying ANOVA test. Correlation of Serum TSH level with the maternal age, parity and gestational age groups were also assessed by Pearson Correlation test. Significant P-value was taken as &lt;0.05. Results: The frequency of SCH found was 19.35% by taking cut off limit of &lt;2.5 IU/L and 3.55% by taking cut off limit of &lt;4.5 IU/L among total of 310 pregnant women. Mean TSH level was 1.84±1.36 IU/L. The mean maternal age was 27.22 ± 4.43 yrs. while median parity was 1. Mean gestational age of these patients were 9.41 ± 2.748 weeks and out of these 160 (51.61%) were between 4-9 weeks and 150(48.38%) between 10-14 weeks. Majority (74%) of these women belonged to lower middle socioeconomic class. Mean TSH level coorelation between different age groups, parity groups and gestational age groups were found to be insignificant. Conclusion: The prevalence of SCH is not so high and mean TSH level in our population was 1.84 IU/L. But to establish reference range for Pakistani population, further studies in population of different backgrounds and geographical distribution needs to be evaluated.

Улучшение исходов ишемического инсульта у пациентов с высоким уровнем свободного трийодтиронина по сравнению с пациентами с гипо- и эутиреозом

Актуальность. Известно, что дисфункция щитовидной железы ассоциирована с повышенным риском развития цереброваскулярных заболеваний. Однако накопленные в течение последних лет экспериментальные данные свидетельствуют о том, что гормоны щитовидной железы могут иметь определенные нейропротекторные эффекты. Цель исследования: определить взаимосвязь между уровнем свободного трийодтиронина в дебюте острого ишемического инсульта и функциональным исходом инсульта через 6 месяцев. Материалы и методы. В исследование был включен 121 пациент с впервые развившимся острым ишемическим инсультом. Концентрации свободного трийодтиронина (свT3), свободного тироксина (свT4), тиреотропного гормона и наличие базисных факторов риска инсульта оценивались в течение 24 часов с момента появления симптомов. Неврологический дефицит оценивался по Скандинавской шкале инсульта (SSS). Неблагоприятный функциональный исход определялся как показатель mRs ≥ 3 баллов через 6 месяцев после перенесенного инсульта. Результаты. Тест ANOVA показал, что пациенты с уровнем свT3 в 4-м квартиле (≥ 5,35 пмоль/л) имели значительно более тяжелый неврологический дефицит по сравнению с пациентами с уровнем свТ3 во 2–3-м квартилях (медиана SSS 48 баллов против 37 баллов, p = 0,0481) и особенно по сравнению с пациентами с уровнем свТ3 в 1-м квартиле (≤ 3,4050 пмоль/л, медиана SSS 48 против 30, p = 0,0018). Согласно тесту Краскала — Уоллиса, пациенты с уровнем свободного Т3 выше 75-го процентиля имели более благоприятный функциональный исход со средним значением по модифицированной шкале Рэнкина 2,5 балла по сравнению с пациентами с уровнем свT3 в 25–75-м процентилях (со средним значением по модифицированной шкале Рэнкина 4 балла). Результаты анализа пробит-регрессии свидетельствуют о дозозависимом влиянии уровня свT3 на вероятность благоприятного исхода инсульта. Уровень свободного Т3 6,56 пмоль/л был связан с 50% вероятностью благоприятного исхода, а уровень свободного Т3 выше 8,67 пмоль/л был ассоциирован с 75% вероятностью благоприятного исхода инсульта. Выводы. Исследование показало, что пациенты с высоким уровнем свободного трийодтиронина при дебюте ишемического инсульта имеют более благоприятный функциональный исход, даже по сравнению с пациентами с нормальным уровнем свободного Т3. Более высокие уровни свободного трийодтиронина также ассоциируются с менее тяжелым неврологическим дефицитом в острой фазе. Выявлено дозозависимое влияние уровня свободного трийодтиронина на вероятность благоприятного исхода инсульта. Полученные данные свидетельствуют о том, что тиреоидный профиль является не только фактором, влияющим на течение ишемического инсульта, но и потенциальной мишенью для терапевтической коррекции.

Low triiodothyronine levels correlate with high B-type natriuretic peptide levels in patients with heart failure

Thyroid hormone metabolism can be closely associated with cardiovascular disorders. We examined the relationship between low triiodothyronine (T3) levels and heart failure status, including B-type natriuretic peptide (BNP) levels, in 625 patients with cardiovascular disorders who underwent cardiac catheterization. A multiple regression analysis revealed that the left ventricular ejection fraction (LVEF), hemoglobin (Hb) levels, sex (male), free T3 (FT3) levels, and estimated glomerular filtration rate (eGFR) were significantly negatively associated with the log BNP value, while age was significantly positively associated with the log BNP value (P < 0.001 each). Furthermore, the log BNP and age were significantly negatively associated with the FT3 levels, while the Hb and body mass index (BMI) were significantly positively associated with the FT3 levels (P < 0.001 each). Theoretically constructed structure equation modeling (SEM) revealed an inverse association between FT3 and BNP (β = −0.125, P = 0.002), and the same relationship remained in the patient group with normal-range BNP values (β = −0.198, P = 0.008). We demonstrated a significant relationship between high BNP and low serum FT3 levels, and this relationship remained significant in patients with normal BNP levels. These results indicate that low T3 is associated with high plasma BNP levels rather than worsening of hemodynamics.

Thyroid Disorders.

Thyroid Disorders.

Clinical features and prognosis of low triiodothyronine syndrome in patients with acute myeloid leukemia

目的探讨伴低T3综合征（LT3S）的急性髓系白血病（AML）患者的临床特征及预后。方法回顾性分析2013年1月至2019年12月江苏省人民医院血液科连续收治的236例AML患者的临床资料，按照血清甲状腺素水平将其分为LT3S组和非LT3S组，比较两组患者的临床特征及预后。结果在236例AML患者中，有62例（26.3％）患者出现LT3S。血清游离三碘甲状腺原氨酸（T3）水平与白蛋白（r＝0.443，P<0.001）、血红蛋白（r＝0.187，P＝0.005）水平呈正相关，与C反应蛋白（r＝−0.406，P<0.001）、乳酸脱氢酶（r＝−0.274, P<0.001）水平呈负相关。LT3S组与非LT3S组相比，总生存（OS）期（7.5个月对29.9个月，P<0.001）和无进展生存（PFS）期（2.0个月对24.0个月，P<0.001）明显缩短。使用倾向性匹配评分均衡患者基线资料后显示，LT3S组与非LT3S组相比OS期（9.6个月对30.4个月，P＝0.010）和PFS期（3.0个月对30.0个月，P＝0.014）仍明显缩短。合并LT3S是影响AML患者OS（HR＝2.553，95％ CI 1.666～3.912，P<0.001）和PFS（HR＝1.701，95％ CI 1.114～2.597，P＝0.014）的独立危险因素。亚组分析提示，在肥胖、体能状态差或采用标准方案化疗的AML亚组中合并LT3S者预后更差。结论LT3S的发生反映AML患者临床状态差，不能耐受高强度化疗，预后不良。

Effect of Micronutrients on Thyroid Parameters.

Micronutrients are involved in various vital cellular metabolic processes including thyroid hormone metabolism. This study aimed to investigate the correlation between serum levels of micronutrients and their effects on thyroid parameters. The correlation of serum levels of micronutrients and thyroid markers was studied in a group of 387 healthy individuals tested for thyroid markers (T4, T3, FT4, FT3, TSH, anti-TPO, RT3, and anti-Tg) and their micronutrient profile at Vibrant America Clinical Laboratory. The subjects were rationalized into three groups (deficient, normal, or excess levels of micronutrients), and the levels of their thyroid markers were compared. According to our results, deficiency of vitamin B2, B12, B9 and Vit-D25[OH] (p < 0.05) significantly affected thyroid functioning. Other elemental micronutrients such as calcium, copper, choline, iron, and zinc (p < 0.05) have a significant correlation with serum levels of free T3. Amino acids asparagine (r = 0.1765, p < 0.001) and serine (r = 0.1186, p < 0.05) were found to have a strong positive correlation with TSH. Valine, leucine, and arginine (p < 0.05) also exhibited a significant positive correlation with serum levels of T4 and FT4. No other significant correlations were observed with other micronutrients. Our study suggests strong evidence for the association of the levels of micronutrients with thyroid markers with a special note on the effect of serum levels of certain amino acids.

The Correlation Between Perfectionism and Serum Thyroid Hormone Levels in Obsessive-Compulsive Personality Disorder Patients.

Perfectionism is one of the leading clinical symptoms of the obsessive-compulsive personality disorder (OCPD). This research aimed to compare perfectionism and serum thyroid hormone levels between individuals with OCPD and healthy individuals of a control group. The serum levels of free T4, free T3, and thyroid-stimulating hormone of 37 patients diagnosed with OCPD and 36 healthy controls with similar sociodemographic traits were measured. Furthermore, the Sociodemographic and Clinical Data Form, the Beck Anxiety Inventory (BAI), the Beck Depression Inventory (BDI), and the Frost Multidimensional Perfectionism Scale (FMPS) were applied to all participants in the study. There was a statistically remarkable correlation between the FMPS total score and the T3 level (r = -0.47, P = .004), and between the BAI and the T3 level (r = -0.41, P = .011). The research findings demonstrated that there could be a correlation between perfectionism and thyroid hormone levels.

P–711 The association between thyroid autoimmunity and serum level of anti-Müllerian hormone in infertile patients with normal ovarian reserve undergoing in vitro fertilisation

Abstract Study question Is there a relationship between thyroid autoimmunity and serum level of anti-müllerian hormon (AMH) in infertile women with normal ovarian reserve undergoing in vitro fertilisation (IVF)? Summary answer In infertile women with normal ovarian reserve serum AMH level above 5ng/ml is associated with higher level of thyroid hormones and less frequent thyroid autoimmunity What is known already Previous studies suggest that thyroid autoimmunity is associated with a decreased ovarian reserve. Moreover, it was reported that thyroid hormone administration could improve serum AMH level. However, the relationship between serum AMH level and thyroid autoimmunity and function in infertile women with normal ovarian reserve undergoing IVF is largely unknown. Since in IVF the serum AMH level is an important marker which dictate the management of the couple, the identification of all the factors possibly related to this parameter is very important. Study design, size, duration: We performed a retrospective study in the Department of Reproductive Medicine of a private hospital. The medical records of all consecutive patients who underwent IVF between January 2015 and December 2018 with all causes of infertility were reviewed. Study group included 581patients with a mean age of 34.4±4.1 years, mean AMH of 3.78±2.4 ng/mL, mean serum TSH level of 1.89±1 microUI/ml and mean serum free T4 level of 1.05±0.98 ng/dl. Participants/materials, setting, methods Patients with known thyroid disorders or under thyroid hormone treatment at the moment of evaluation were excluded. Only patients with serum level of thyroid stimulating hormone (TSH), free tyroxine (free T4), anti thyroid peroxidase antibodies (ATPO,) anti thyroglobulin antibodies (ATG), AMH and age available for analysis were included in the study. This parameters are evaluated on a systematic basis in all the patients undergoing IVF in our Department, except very few cases. Main results and the role of chance Patients were divided according to their serum AMH level in two groups: group 1 with AMH level 5 ng/ml and below (n = 450 patients) and group 2 with AMH above 5 ng/ml (n = 131 patients). When the two groups were compared we found that patients in group 2 were younger in comparison with patients in group 1 (32.9±3.8 versus 35±4 years, p &amp;lt; 0.0001). After adjustment for age, patients in group 2 had significantly higher serum free T4 level (1.07±0.12 versus 1.04±0.14 ng/dl, p = 0.015), lower ATG (17.59±41.8 UI/ml versus 39.4±136.16 UI/ml, p &amp;lt; 0.018) and presented less frequently with high ATPO antibodies (35% versus 41.8%, p = 0.047). In a logistic regression model with AMH as a dependent variable, free T4, but not TSH was independently and positively associated with higher AMH levels (above 5 ng/ml) (p = 0.025) after adjustment for anti thyroid antibodies levels. Morever, in this logistic model the presence of high ATPO, but not ATG, were negatively related to higher AMH level (p = 0.037). Limitations, reasons for caution Patients included in this study are infertile patients with indication for IVF treatment. Therefore, the results of this study should be used with caution in other populations Wider implications of the findings: Our study suggest that serum AMH level might be related to thyroid autoimmunity, but also to thyroid hormones levels. If confirmed by further studies, this findings could offer a way to improve serum AMH level and to better understand the markers of ovarian reserve in an IVF setting. Trial registration number NA

The Correlation Between Low Serum T3 Levels and All-Cause and Cardiovascular Mortality in Peritoneal Dialysis Patients.

ObjectiveThis study is to investigate the correlation between serum triiodothyronine (T3) levels and all-cause and cardiovascular mortality in PD patients.MethodsA total of 376 end-stage renal disease (ESRD) patients who started maintenance PD treatment in the Department of Nephrology in our hospital and stable treatment for ≥3 months were selected, and the total T3 (TT3) and free T3 (FT3) levels were determined. Among them, 168 cases with FT3 <3.5 pmol/L and/or TT3 <0.92 nmol/L were divided into the low serum T3 level group, and the remaining 208 cases were divided into normal serum T3 level group. The Cox survival analysis method was used to analyze the correlation between low serum T3 levels and all-cause and cardiovascular mortality in PD patient.ResultsCompared with the normal serum T3 level group, patients with low serum T3 levels had higher systolic blood pressure and a higher proportion of heart disease, and lower levels of total T4, free T4, hemoglobin, serum albumin, blood calcium, serum total bilirubin, alanine aminotransferase, and 24-h urine volume (all P < 0.05). Binary Logistic regression analysis showed that heart disease (P = 0.003, OR: 2.628, 95% CI: 1.382–4.997) and high TT4 level (P < 0.001, OR: 0.968, 95% CI: 0.956–0.979) were related to low serum T3 levels in PD patients. Multivariate Cox regression analysis showed that low serum FT3 level was an independent risk factor for all-cause death in PD patients (HR = 0.633, 95% CI = 0.431–0.930; P < 0.020).ConclusionLow serum T3 levels in PD patients were associated with heart disease and TT4 levels. Low serum FT3 levels were associated with the risk of all-cause death in PD patients.

Relapse Rate and Clinical Risk Factors Affecting the Treatment of Graves’ Disease

Objective: To determine the relapse rate of Graves’ disease (GD) and identify important clinical risk factors for relapse.Materials and Methods: This was a 10-year retrospective cohort study. Information was collected with ICD10 E050 codes for Graves’ hyperthyroidism among Thai patients of both sexes and all ages with no history of pregnancy, thyroid storm or antithyroid drug (ATD) allergy.Results: The 286 included GD patients had a relapse rate of 35% after ATD withdrawal for one year. The clinical risk factors associated with relapse were male sex (p = 0.014), smoking (p = 0.001), serum free T4 (FT4) levels &gt; 2 times the upper normal range at diagnosis (p = 0.005), duration for maintenance treatment &lt; 6 and 9 months (p &lt; 0.005) compared with remission. A TSH level &lt; 1 mIU/L (p = 0.060) and MMI &gt; 2.5 mg per day before ATD withdrawal (p = 0.094) trended toward associations with relapse. The clinical factors that predicted GD relapse were serum FT4 levels at diagnosis (p = 0.006) and serum free T3 (FT3) levels before ATD withdrawal (p = 0.019).Conclusion: Male sex, smoking and serum FT4 levels at diagnosis &gt; 2 times the normal range were significant clinical factors for GD relapse in Thai patients. To reduce the relapse rate in the first year, MMI should be used in maintenance periods for 9 to 12 months with serum FT3 levels within low-normal ranges before ATD withdrawal. This would promote future guidelines for GD management in Thailand.

Relationship between vitamin D and autoimmune Hashimoto's thyroiditis in Gharbiya Governorate

Background There are many reports about the association between low vitamin D (vit D) level and autoimmune thyroid diseases. Several researches have shown that supplementing vit D suppresses the autoimmune reaction reducing the level of thyroid autoantibodies. Aim The purpose of the study is to assess the relationship between vitamin D deficiency and autoimmune Hashimoto's thyroiditis (HT). Patients and methods This case–control study was conducted on 60 cases that were divided into two groups. Group A included 30 healthy cases serving as the control group and group B included 30 patients with known HT. Laboratory investigations including serum concentration of 25(OH)D3, serum calcium (Ca) and phosphorus (Ph), total and free T3, free T4, thyroid-stimulating hormone (TSH), antithyroid peroxidase, and anti-thyroglobulin antibodies, C-reactive protein, and erythrocyte sedimentation rate were done. Results Serum 25 (OH)D3 was significantly lower in HT patients compared with healthy controls. The incidence of 25(OH)D3 deficiency was increased in those patients. Comparison between the patient and control groups regarding serum Ca and serum Ph levels were statistically nonsignificant. Higher TSH, erythrocyte sedimentation rate, and C-reactive protein with lower serum T3, free T3, and free T4 levels were significantly higher with HT. Antithyroid peroxidase was elevated in all HT patients. Anti-thyroglobulin was elevated in all HT cases. There was a significant negative correlation between vit D level and the TSH and a significant positive correlation between vit D level and the Ca. Conclusion In HT patients, vitamin D deficiency is common, suggesting its role in developing the disease.

The Comparison between Free Thyroxine and Thyroid-Stimulating Hormone Levels on Melasma Severity: A Cross-Sectional Study

Background: Melasma has been suspected to be linked with levels of thyroid hormone. There is no study that explains the association between thyroid hormone level with melasma severity. Objective: This study aims to find the discrepancies in the levels of thyroid hormone in varying severity of melasma by using two different measurement techniques. Methods: Subjects were chosen consecutively from the dermatology clinic at RSUPN Dr. Cipto Mangunkusomo hospital. Forty-eight patients participated in this study were categorized into mild melasma and moderate-severe melasma based on modified melasma area and severity index (mMASI) and Janus II measurement. Results: Statistically, mMASI measurement showed no significant association between varying melasma severity with levels of thyroid stimulating hormone and free T4 (FT4), P 0.375 and P 0.208, respectively. The Janus II examination using polarized light modality has a weak positive correlation with the serum FT4 level (r=0.3; P 0.039). Weak correlation was also found between the two measurement strategies, Janus II and mMASI (r= 0.314; P 0.03). Conclusion: There are no significant differences observed in levels of thyroid hormone between subjects with varying degrees of melasma severity.

Relationship Between Iodine Status and Thyroid Function in Preschool Children: From the Environmental and Development of Children (EDC) Study

Background: We investigated iodine status and its association with thyroid function among preschool children residing in iodine-sufficient area. Methods: From the Environment and Development of Children study, 477 children were evaluated for thyroid function and urine iodine concentration (UIC) at age 6 during 2015-2017. After excluding children born with multiple birth and with congenital hypothyroidism or Hashimoto thyroiditis, 439 (231 boys) were included. Subclinical hypothyroidism (SCH) was defined as thyroid stimulating hormone (TSH) levels between 4.9-10 μIU/mL with normal free T4 levels. Iodine status was evaluated by UIC and children were categorized into 4 groups: iodine deficient (UIC < 100 μg/L), adequate (UIC, 100-299 μg/L), mild excessive (UIC, 300-999 μg/L), severe excessive (UIC ≥ 1000 μg/L). Results: Goiter was palpated in 64 (14.6%) with female predominance (26.0% vs. 4.3%, P < 0.001). Serum level of free T4 and T3 was 1.2 ± 0.1 ng/dL and 148.1 ± 18.5 ng/dL, respectively. The median TSH level was 2.3 (0.53-8.59) μIU/mL and the prevalence of SCH was 4.3% without sex-difference. The median UIC level was 606.2 (19.9-16409.7) μg/L, higher in boys (684 vs. 545 μg/L, P = 0.021) than in girls. Iodine was deficient in 19 (4.3%), adequate in 96 (21.9%), mild excessive in 170 (38.7%), and severe excessive in 145 (35.1%). After excluding 19 iodine deficient children, the relationship between iodine status and thyroid function was evaluated by multiple regression analysis after adjusting for age, sex, birth weight, gestational age, body mass index Z-score, and family history. As iodine status increased from adequate, mild excessive to severe excessive group, T3 levels decreased, and TSH levels increased with marginal significance (P for trend < 0.1 for T3 and TSH). When stratified by sex, similar association was found in only girls (P for trend = 0.043 for T3, and 0.062 for TSH) but not in boys, and mild excessive group showed lower free T4 levels (β = -0.05, P = 0.013) and severe excessive group had lower T3 levels (β = -7.04, P = 0.035) than iodine adequate group in only girls, but not in boys. Conclusion: Iodine was deficient in 4.3%, adequate in 21.9%, and excessive in 73.8% among preschool children residing in South Korea. As iodine status increased from adequate to excessive group, TSH levels increased with decreasing free T4 and T3 levels in girls.

Leptin Regulates Hypothalamus-Pituitary-Thyroid Axis via TRH in Energy Expenditure During Fasting: The Study on TRH Deficient Mouse

Abstract Objectives: The hypothalamic-pituitary-thyroid (HPT) axis plays a significant role in the regulation of energy expenditure. Previous reports demonstrated that thyroid hormones are critically involved in metabolic process, and hypothyroidism was induced by fasting. The mechanism by which TRH neurons sense alterations in peripheral energy stores is supposed to be regulated by leptin, an adipose tissue-derived hormone. Leptin was initially considered as a hormone to prevent obesity, it was later showed that the major role of leptin is to signal the switch from the fed to the starved state at the hypothalamic level. Recently, we generated TRH-deficient mice (TRH-/-). The mice exhibit tertiary/central hypothyroidism with characteristic elevation of serum TSH level and diminished TSH biological activity. In this study, we used TRH-/- to investigate the physiological role of TRH in fasting energy expenditure, including the mechanism regulated by leptin. Methods: Twelve-week-old male F2 hybrid ICR mice were used in this study. (1) Wild-type mice (WT) and TRH-/- were fasted up to 50 hrs. Blood samples were collected from tail veins at various points. Anterior pituitary samples were obtained from euthanized mice before and after 16 hrs fasting. (2) Serum free T4 (FT4) and TSH levels assessed. (3) The expression level of TSHβ mRNA in anterior pituitary were detected using qPCR assays. (4) We repeated these experiments using mice with leptin administration; leptin (0.5μg/g•BW) was administrated every 6 hours starting at after 2 hours fasting. Results: In WT, the level of FT4 was decreased chronologically during fasting to approximately 50% at 50 hrs after fasting. Serum TSH decreased to 70% and the expression level of TSHβ mRNA in anterior pituitary also decreased to 30% compared to before fasting. Administration of leptin recovered the level of FT4 to basal level. However, the level of serum TSH and TSHβ mRNA in pituitary were not recovered to basal levels. By contrast, in TRH-/-, the level of FT4 were also decreased after fasting indicating that the decrease of FT4 by fasting was independent of TRH. However, the level of FT4 was not recovered by leptin suggesting that the recovery of FT4 by leptin was TRH dependent. Serum TSH level decreased to 75% after fasting, and no recovery to basal level with leptin administration was observed in TRH-/- same as WT. In TRH-/-, the pituitary TSHβ mRNA expression level was about 50% of WT before fasting. It did not correlate with the serum TSH level. In addition, no increase in TSHβ mRNA expression level by leptin administration was observed in TRH-/-. These findings suggested that the TSHβ mRNA expression level in the pituitary is completely TRH-dependent in TRH-/-. Conclusion: Fasting-induced hypothyroxinemia was independent of TRH. Leptin regulates H-P-T axis via TRH during fasting-induced energy expenditure. Leptin may modulate the biological activity of TSHβ.

Corneal Tomographic Analysis Among Patients With Thyroid Gland Dysfunction.

To analyze the corneal tomographic parameters of patients with thyroid gland dysfunction. This case-control study included 100 eyes of 50 patients with thyroid gland dysfunction and 100 eyes of 50 healthy controls. All eyes were examined by Pentacam (Oculus Optikgeräte GmbH). Pentacam parameters were compared between patients with thyroid gland dysfunction and controls. Spearman's correlation coefficient between different Pentacam parameters and the serum level of free thyroxin (T4) and thyroid-stimulating hormone (TSH) was calculated. Patients with hypothyroidism had significantly higher median values of steep and maximum simulated keratometric readings, central corneal thickness (CCT), and thinnest pachymetry (CTmin) than both patients with hyperthyroidism and controls (P⩽ .05). The median values of the average and maximum pachymetric progression index (PPI), posterior elevation, and back difference elevation were significantly higher in patients with hyperthyroidism than in patients with hypothyroidism and controls (P ⩽ .05). The Ambrósio Relational Thickness (ARTmax) was significantly reduced in patients with hyperthyroidism (P ⩽ .001). Both CCT and CTmin showed a moderately positive correlation with serum TSH level and a moderately negative correlation with serum free T4 level. Patients with non-autoimmune thyroid gland dysfunction had significantly thinner CCT, CTmin, and inferior vertical deviation than the autoimmune group (P ⩽ .05). Thyroid gland dysfunction is associated with significant corneal tomographic changes. Patients with hyperthyroidism tend to have thinner corneas and more abnormal tomographic parameters correlating with keratoconus. No significant tomographic changes were found in association with autoimmune thyroid gland dysfunction. The authors recommend screening and regular follow-up of patients with thyroid gland dysfunction for early detection and management of keratoconus. [J Refract Surg. 2021;37(3):192-197.].

Prospective study of thyroid functions in multiple sclerosis patients treated with interferon beta in Alexandria University MS clinic

BackgroundThe incidence of thyroid dysfunction in multiple sclerosis (MS) patients on interferon (as a disease-modifying line) has been reported in many studies performed on patients already on interferon therapy. Our study adopted a prospective follow-up of the thyroid profile in those patients newly starting interferon beta therapy over 1 year trying to find a correlation between the start of therapy and the occurrence of this dysfunction.ObjectivesTo evaluate the incidence of thyroid dysfunction in MS patients before and 1 year after of interferon beta.MethodsA prospective cohort study on 48 MS patients newly receiving interferon beta therapy through MS clinic were subjected to assessment of thyroid profile including serum TSH, free T3, and T4 at the start of treatment; they were followed-up at 6- and 12-month intervals after the start of therapy.Results and conclusionThere was a statistically significant increase in serum-free T3 levels in those treated with interferon beta therapy in a follow-up of 1 year. Our work also showed a decrease in serum-free T4 levels without statistical significance. TSH levels showed a tendency towards increase without statistical significance.

English

BACKGROUND Thyroid disease is more common in people with diabetes mellitus than in general population. Among thyroid disorders, subclinical hypothyroidism is more common than the overt form. Hypothyroidism is associated with dyslipidaemia, hypertension and cardiac disease. Subclinical hypothyroidism has also been reported to have these features. With this background, we aimed to determine the prevalence of subclinical thyroid disorder and its influence on the metabolic profile of patients with type 2 diabetes mellitus (DM). METHODS 234 type 2 diabetes patients, 117 males and 117 females, who were previously not known to have thyroid disease, were screened for thyroid dysfunction using serum free T3, free T4, and thyroid stimulating hormone (TSH) levels. Patients were evaluated for clinical features of thyroid disease and investigated for microvascular complications of DM, dyslipidaemia and cardiac disease. Individuals with subclinical hypothyroidism were further screened for anti-thyroid peroxidase (TPO) antibodies. RESULTS In this study, subclinical hypothyroidism was present in 29 (12.4 %) of 234 type 2 diabetics; no case of subclinical hyperthyroidism was detected. 25 of these 29 patients with subclinical hypothyroidism were females. Elevated TPO antibody levels were present in 82.8 % (24 out of 29) subclinical hypothyroidism (SCH) patients. SCH was found to be associated with higher body mass index (BMI) and patients aged more than 50 years. No significant difference was found in glycaemic profile or lipid profile between patients with SCH and euthyroid subjects. There was no significant difference among SCH patients with and without microvascular complications. Left Ventricle (LV) diastolic dysfunction was present in 34.4 % of SCH patients. CONCLUSIONS SCH is common among type 2 diabetics, especially in females and most commonly due to autoimmune thyroid disease. SCH in type 2 DM is associated with a higher BMI and an older age group, but it does not seem to have an influence on glycaemic profile, lipid profile or microvascular complications of diabetes. KEYWORDS Thyroid Stimulating Hormone (TSH), Type 2 Diabetes Mellitus (T2DM), Subclinical Hypothyroidism (SCH), BMI, Anti–TPO (Thyroid Peroxidase) Antibody

Effect of sleeve gastrectomy on thyroid-stimulating hormone levels in morbidly obese patients with normal thyroid function.

There are many studies, which demonstrate that morbid obesity is associated with an increase in Thyroid Stimulating Hormone (TSH) levels. However, the effect of Laparoscopic Sleeve Gastrectomy (LSG) procedure on postoperative TSH levels is not clear. This study aims to evaluate the effect of weight loss after LSG procedure on TSH levels in euthyroid patients with morbid obesity. 159 Euthyroid patients who applied for an LSG procedure (93.7% female, with a mean age of 34.18±10.01 years, BMI 43.2±6.82 kg/m2) were retrospectively analyzed for the study. The parameters used in the analysis were their serum free T3 levels (fT3), free T4 levels (fT4), and TSH levels preoperatively and at 6 months after surgery. The postoperative correlation between TSH and BMI (Body Mass Index), % EWL (Percent Excess Weight Loss), and % TWL (Total Weight Loss) levels were evaluated. Mean BMI change from 43.2±6.82 kg/m2 to 30.48±5.63 kg/m2 (p<0.001), 6 months after LSG, was associated with a mean reduction in the TSH from 2.27±1.09 µU/dL to 1.61±0.99 µU/dL; p<0.001). Serum fT3 levels (3.23±0.42 ng/dL at baseline and 3.21±0.48 ng/dL at 6 months after surgery; p=0.409) remained steady. Serum fT4 levels (1.21±0.18 µU/dL at baseline and 1.43±0.20 µU/dL at 6 months after LSG; p<0.001) increased. Change in TSH was significantly correlated with change in BMI at 6 months after surgery (r=0.200, p=0.015). However, the decrease in TSH following LSG procedure did not correlate with % EWL (r=-0.114, p=0.159) and % TWL (r=-0.100, p=0.209). After the LSG procedure, there was a significant decrease in TSH levels and a significant increase in fT4 levels, but no change was seen in fT3 levels. While this decrease in TSH levels showed a positive correlation with BMI, no statistically significant correlation was found with % EWL and % TWL.