Maternal adiposity, smoking, and thyroid function in early pregnancy

Objective: A high activity of the deiodinase type 2 has been proposed in overweight, obese, and smoking pregnant women as reflected by a high triiodothyronine (T3)/thyroxine (T4)-ratio. We speculated how maternal adiposity and smoking would associate with different thyroid function tests in the early pregnancy. Design: Cross-sectional study within the North Denmark Region Pregnancy Cohort. Methods: Maternal thyroid-stimulating hormone (TSH), total T4 (TT4), total T3 (TT3), free T4 (fT4), and free T3 (fT3) were measured in stored blood samples (median gestational week 10) by an automatic immunoassay. Results were linked to nationwide registers and live-birth pregnancies were included. The associations between maternal adiposity (overweight or obese), smoking, and log-transformed TSH, fT3/fT4-ratio, and TT3/TT4-ratio were assessed using multivariate linear regression and reported as adjusted exponentiated β (aβ) with 95% confidence interval (CI). The adjusted model included maternal age, parity, origin, week of blood sampling, and diabetes. Results: Altogether 5,529 pregnant women were included, and 40% were classified with adiposity, whereas 10% were smoking. Maternal adiposity associated with higher TSH (aβ 1.13 (95% CI 1.08-1.20)), whereas maternal smoking was associated with lower TSH in the early pregnancy (0.875 (0.806-0.950)). Considering the T3/T4-ratio, both maternal adiposity (fT3/fT4-ratio: 1.06 (1.05-1.07); TT3/TT4-ratio: 1.07 (1.06-1.08)) and smoking (fT3/fT4-ratio: 1.07 (1.06-1.09); TT3/TT4-ratio: 1.10 (1.09-1.12)) associated with a higher ratio. Conclusions: In a large cohort of Danish pregnant women, adiposity and smoking showed opposite associations with maternal TSH. On the other hand, both conditions associated with a higher T3/T4-ratio in early pregnancy, which may reflect altered deiodinase activity.

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Thyroid Function Test as First-line Investigation of Hypernatremia: Is It Necessary?

Asian Journal of Medicine and Biomedicine ◽

10.37231/ajmb.2020.4.1.322 ◽

2020 ◽

Vol 4 (1) ◽

pp. 12-18

Author(s):

Nada Syazana ◽

Huzairi Sani ◽

Zahir Izuan Azhar

Keyword(s):

Thyroid Function ◽

Strong Association ◽

Thyroid Function Test ◽

Tertiary Hospital ◽

Cross Sectional Study ◽

Thyroid Stimulating Hormone ◽

Bivariate Analysis ◽

Thyroid Function Tests ◽

First Line ◽

Cross Sectional

Non-severe hypothyroidism has no strong association with hyponatremia. However, thyroid function tests (TFT) continue to be ordered as a first-line investigation. The objective of this study was to establish the prevalence of inpatient hyponatremia and to reiterate the association between thyroid disorders and hyponatremia based on study findings and current literature. A cross-sectional study on 3,478 in-patients adults of both gender admitted to a Malaysian tertiary hospital was carried out. Age, gender, sodium levels, thyroid stimulating hormone (TSH), free thyroxine (fT4) and clinical notes between 1/11/17-31/12/17 were extracted from the hospital’s information system. Bivariate analysis was performed using Mann-Whitney U, Chi-square and Spearman correlation tests. 21.9% of inpatients had hyponatremia of which 52% were mild. 359 (69%) of hyponatremic patients had a TFT sent where 71.9% were euthyroid. Sodium level is significantly correlated with age (R=-0.257, P<0.001). No correlations were found between sodium and TSH and fT4. Sodium was significantly lower in the non-thyroidal illness (NTI) group compared to the hypothyroid group. No significant differences in sodium were found between the hypothyroid group and other thyroid states. Hence it was conclude that in hyponatremia, TFT is indicated when there is clinical evidence of severe hypothyroidism, suspicion of hypothalamus-pituitary-axis disorder or when no cause of SIADH is apparent. Otherwise, TFT is unnecessary and costly as a first-line investigation. Keywords: hyponatremia, hypothyroidism, hypothyroid, non-thyroidal illness, sodium

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Normal Reference Range for Serum TSH, Free T4, Total T4, and Total T3 on Roche® Platforms in Basrah, Iraq

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i45a32727 ◽

2021 ◽

pp. 147-155

Author(s):

Nassar Taha Alibrahim ◽

Samih Abed Odhaib ◽

Ali Hussain Alhamza ◽

Ammar Mohammed Saeed Almomin ◽

Ibrahim Abbood Zaboon ◽

...

Keyword(s):

Thyroid Function ◽

Reference Range ◽

Cross Sectional Study ◽

Reference Intervals ◽

Specific Reference ◽

Thyroid Function Tests ◽

Free T4 ◽

Cross Sectional ◽

Normal Reference Range ◽

Tertiary Center

Background: Thyroid function tests are mandatory in clinical practice because symptoms and signs are not reliable to discriminate between various types of thyroid disease. Aim: The aim of this study was to determine assay-specific reference range for serum free T4, total T4, total T3 and TSH among healthy non-pregnant adult cohort for Roche® platforms in Basrah (Southern Iraq) from single laboratory in a tertiary center using indirect approach of the available data. Methods: A Cross sectional study for non-pregnant adults 19 years and above. Sera were analyzed by using cobs e411 for thyroid functions tests. Results: Total enrolled persons were 10,078. The 95% reference intervals for TSH were 0.20-6.50 μIU/mL, which increased with age though not linear, for free T4 were 0.8-1.70 ng/dL, for total T4 were 3.78-15.33 μg/dL, and for total T3 were 0.80-2.50 ng/mL. Colcusion: Cobs e411(Roche® analytical platform) analyzer reference range for thyroid function cannot be applied for Iraqi population .

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HbA1c is inversely associated with thyroid cysts in a euthyroid population: A cross-sectional study

PLoS ONE ◽

10.1371/journal.pone.0253841 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0253841

Author(s):

Yuji Shimizu ◽

Shin-Ya Kawashiri ◽

Yuko Noguchi ◽

Yasuhiro Nagata ◽

Takahiro Maeda ◽

...

Keyword(s):

Thyroid Function ◽

Cross Sectional Study ◽

Thyroid Stimulating Hormone ◽

Thyroid Peroxidase ◽

Sectional Study ◽

Normal Range ◽

Free Triiodothyronine ◽

Free T4 ◽

Cross Sectional ◽

Normal Thyroid Function

Anti-thyroid peroxidase antibody (TPO-Ab) is revealed to be inversely associated with thyroid cysts among euthyroid population. TPO-Ab causes autoimmune thyroiditis by bolstering thyroid inflammation. Therefore, at least partly, absence of thyroid cysts could indicate latent thyroid damage. Since participants with subclinical hypothyroidism are reported to have higher HbA1c than normal healthy controls, HbA1c could be inversely associated with thyroid cysts through a mechanism reflecting latent thyroid damage. To investigate the association between HbA1c and thyroid cysts among a euthyroid population, a cross-sectional study was conducted on 1,724 Japanese individuals who were within the normal range of thyroid function [i.e., normal range of free triiodothyronine (T3) and free thyroxine (T4)] and aged 40–74 years. Among this study population, 564 were diagnosed with thyroid cysts. Independently of thyroid related hormones [thyroid stimulating hormone (TSH), free T3, and free T4] and known cardiovascular risk factors, HbA1c was found to be significantly inversely associated with the presence of thyroid cysts. This association remained significant even after this analysis was limited to participants within a normal range of TSH. The fully adjusted odds ratios (ORs) of thyroid cysts for 1 standard deviation (SD) increment of HbA1c were 0.84 (0.74, 0.95) for total participants and 0.80 (0.70, 0.92) for participants within a normal range of TSH. Among participants with normal thyroid function, HbA1c was inversely associated with the presence of thyroid cysts. The absence of thyroid cysts and higher levels of HbA1c could indicate the latent functional damage of the thyroid.

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Retrospective analysis of thyroid function in drug-free patients with bipolar disorder in China

10.21203/rs.2.19666/v1 ◽

2019 ◽

Author(s):

Bin Yang ◽

Yan Zhong Li ◽

Qi Wang ◽

Xin Sheng Guo ◽

Ying Zhao ◽

...

Keyword(s):

Bipolar Disorder ◽

Thyroid Function ◽

Bipolar Depression ◽

Cross Sectional Study ◽

Thyroid Stimulating Hormone ◽

Thyroid Function Tests ◽

Free Triiodothyronine ◽

Cross Sectional ◽

Female Patients ◽

Previous Hospitalization

Abstract Background Bipolar disorder is a common mental illness with serious consequences. Clinical studies have found that thyroid function may have an impact on patients with bipolar disorder, but there are few relevant studies in China. So this study explores the characteristics of thyroid function in patients with bipolar disorder in China.Methods Using retrospective cohort study and a cross-sectional study, thyroid function tests were performed in inpatients from September 2015 to January 2018 in the Second Affiliated Hospital of Xinxiang Medical University, who were diagnosed with bipolar disorder and were not treated with medications for at least three months before hospitalization.Results We found that the triiodothyronine (T3) and free triiodothyronine (FT3) levels were significantly higher in bipolar mania than in bipolar depression (P < 0.01). The thyroid stimulating hormone (TSH) levels were significantly lower in male than female patients, while the FT3, free thyroxine (FT4) levels were higher in male than female patients (P < 0.01). Patients were divided into two groups: those who used lithium and those who did not. Both groups had a tendency of hypothyroidism after treatment. In addition, the T3 and FT3 levels were significantly higher in manic than in depressive status in those patients who had a transition between mania and depression in 28 patients compared with previous hospitalization (P < 0.05).Conclusion Patients with bipolar disorder may develop thyroid dysfunction at different stages and in male/female sexes.

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Reference Intervals of Thyroid Hormones and Correlation of BMI with Thyroid Function in Healthy Zhuang Ethnic Pregnant Women

BioMed Research International ◽

10.1155/2018/2032413 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Yonghong Sheng ◽

Dongping Huang ◽

Shun Liu ◽

Xuefeng Guo ◽

Jiehua Chen ◽

...

Keyword(s):

Thyroid Hormones ◽

Pregnant Women ◽

Thyroid Function ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Specific Reference ◽

American Thyroid Association ◽

Reference Ranges ◽

Free Triiodothyronine ◽

Cross Sectional

Ethnic differences in the level of thyroid hormones exist among individuals. The American Thyroid Association (ATA) recommends that an institution or region should establish a specific thyroid hormone reference value for each stage of pregnancy. To date, a limited number of studies have reported the level of thyroid hormones in Chinese minorities, and the exact relationship between BMI and thyroid function in pregnant women is ill. This study was performed to establish trimester-specific reference ranges of thyroid hormones in Zhuang ethnic pregnant women and explore the role of body mass index (BMI) on thyroid function. A total of 3324 Zhuang ethnic health pregnant women were recruited in this Zhuang population-based retrospective cross-sectional study. The values of thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by automatic chemiluminescence immunoassay analyzer. Multivariate linear regression and binary logistic regression were constructed to evaluate the influence of BMI on the thyroid function. The established reference intervals for the serum thyroid hormones in three trimesters were as follows: TSH, 0.02–3.28, 0.03–3.22, and 0.08-3.71 mIU/L; FT4, 10.57–19.76, 10.05–19.23, and 8.96–17.75 pmol/L; FT3, 3.51–5.64, 3.42–5.42, and 2.93–5.03 pmol/L. These values were markedly lower than those provided by the manufacturers for nonpregnant adults which can potentially result in 6.10% to 19.73% misclassification in Zhuang pregnant women. Moreover, BMI was positively correlated with isolated hypothyroxinemia (OR=1.081, 95% CI=1.007–1.161), while the correlation between the BMI and subclinical hypothyroidism was not statistically significant (OR=0.991, 95% CI=0.917–1.072). This is the first study focusing on the reference ranges of thyroid hormones in Guangxi Zhuang ethnic pregnant women, which will improve the care of them in the diagnosis and treatment. We also found that high BMI was positively associated with the risk of isolated hypothyroxinemia.

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A comparative study on outcomes of preprandial versus postprandial thyroid function test

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20194945 ◽

2019 ◽

Vol 5 (6) ◽

pp. 1662

Author(s):

Vasim Ismail Patel ◽

Akshay B. K.

Keyword(s):

Thyroid Function ◽

Subclinical Hypothyroidism ◽

Clinical Symptoms ◽

Thyroid Function Test ◽

Thyroid Stimulating Hormone ◽

Endocrine Gland ◽

Thyroid Function Tests ◽

Sample Collection ◽

Free T4 ◽

Group 2

Background: The thyroid is an endocrine gland. It secretes two hormones thyroxine (T4), triiodothyronine (T3). Hypothyroidism is a common condition encountered by a clinician. Subclinical hypothyroidism (SCH) defined as normal free thyroxine (T4) and elevated thyroid stimulating hormone (TSH), is primarily a biochemical diagnosis with or without clinical symptoms. Studies have observed that TSH levels vary at different times in a day. In practice not much importance is given to the timing of the sample collection (pre-prandial or post-prandial sate). SCH is diagnosed depending on TSH value. So the condition may be under or over diagnosed based on a single value. So we conducted this study to determine whether timing of sample collection had any significant relationship in the determination of levels of thyroid hormones.Methods: The study was carried on 114 patients who visited ENT department, NMCH between July 2018 and June 2019. Group-1 consisted of 38 normal patients. Group-2 consisted of 36 hypothyroidism patients GROUP-3 consisted of 40 subclinical hypothyroidism patients. Thyroid function tests (TSH and free T4) were done in fasting state and 2 hours postprandially. Results: TSH values were found to be significantly lowered after food in all the three groups. Free T4 values did not show any statistically significant alteration after food.Conclusions: There was a significant decline in TSH values postprandially. This might lead to inappropriate diagnosis and management of patients as cases of hypothyroidism, especially in cases of sub clinical hypothyroidism.

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Thyroid dysfunction in patients of metabolic syndrome: A study from a tertiary care center in India

Asian Journal of Medical Sciences ◽

10.3126/ajms.v12i10.38313 ◽

2021 ◽

Vol 12 (10) ◽

pp. 47-50

Author(s):

Ritu Gupta ◽

Akhil K Vijayan ◽

Sushma Choudhary

Keyword(s):

Metabolic Syndrome ◽

Thyroid Dysfunction ◽

Care Center ◽

Tertiary Care ◽

Cross Sectional Study ◽

Thyroid Stimulating Hormone ◽

P Value ◽

Overt Hypothyroidism ◽

Free T4 ◽

Cross Sectional

Background: Metabolic syndrome is characterized by hypertension, dyslipidemia, central obesity, glucose intolerance, insulin resistance. Thyroid hormone acts as general pacemaker, accelerating metabolic process and may be associated with metabolic syndrome. There is no information available in literature regarding the prevalence and association of thyroid dysfunction in metabolic syndrome in this central region of the country. Aims and Objective: To estimate the prevalence of thyroid dysfunction in patients of metabolic syndrome. Materials and Methods: It is a duration based prospective cross sectional study including 200 patients of metabolic syndrome. A detailed history, clinical examination and relevant investigations including serum Free T4 (FT4), Free T3 (FT3), Thyroid Stimulating Hormone (TSH) were done. Range, frequencies, percentage, mean, standard deviation and P value were calculated. P value of < 0.05 was taken as significant. Results: Prevalence of thyroid dysfunction in metabolic syndrome patients was 28.5%. Prevalence of subclinical and overt hypothyroidism was 18.5% and 8.5% respectively. In patients with both metabolic syndrome and thyroid dysfunction, most common components associated are diabetes mellitus and hypertriglyceridemia. Conclusion: Thyroid dysfunction is significantly common in metabolic syndrome patients. It should be aggressively detected and treated in these patients for better outcome.

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Screening of Thyroid Function in the First Half of Pregnancy

Bangladesh Journal of Obstetrics & Gynaecology ◽

10.3329/bjog.v29i1.30440 ◽

2016 ◽

Vol 29 (1) ◽

pp. 26-31

Author(s):

Shaila Naznine Tania ◽

Ferdousi Islam

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Serum Levels ◽

Cross Sectional Study ◽

Thyroid Disorder ◽

Eligibility Criteria ◽

Cross Sectional ◽

Medical College ◽

One Year ◽

Serum Tsh

Objective: The study was conducted to find out any alterations in thyroid function status in first half of pregnancy (up to 20 weeks), with ultimate aim of deciding the usefulness of routine screening of thyroid function in pregnancy.Material and methods: A cross-sectional study was conducted in the department of Obstetrics & Gynaecology, Dhaka Medical College and Hospital, Dhaka, Bangladesh, over a period of one year from July 2011 to June 2012 on pregnant women in their 1st half of pregnancy to screen for the thyroid function. Based on predefined eligibility criteria, a total of 230 pregnant women were purposively included in the study. Thyroid function status was assessed by measuring serum levels of TSH, free thyroxine (FT4), and free tri-iodothyronine (FT3). Women with thyroid disorders were excluded.Results: The mean age of the patients being 24 years. Over 90% of the women were housewife and majority (88.7%) was educated. Over one-quarter of women was overweight with mean body mass index being 22.1 ± 4.4 kg/m2. The women were predominantly multigravida with 56% in 1st trimester 44% in the 1st half of 2nd trimester of pregnancy (13-20 weeks). Based on trimesters specific range of serum TSH in the 1st and 1st half of 2nd trimester (13-20 weeks) of pregnancy,13% of the patients were hypothyroid and 3% were hyperthyroid thus yielding a total of 37(16%) pregnant women with abnormal thyroid function status.Conclusion: The study concluded that one in every six women may have thyroid disorder in the first half of pregnancy and subclinical hypothyroidism is four times more common than the subclinical hyperthyroidism.Bangladesh J Obstet Gynaecol, 2014; Vol. 29(1) : 26-31

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Thyroid Function and 25 (OH) Vitamin D Level among Sudanese Women in Early Pregnancy

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2018.125 ◽

2018 ◽

Vol 6 (3) ◽

pp. 488-492

Author(s):

Imad R. Musa ◽

Duria A. Rayis ◽

Mohmamed A. Ahmed ◽

Ammar H. Khamis ◽

Abubakr M. Nasr ◽

...

Keyword(s):

Vitamin D ◽

Thyroid Function ◽

Early Pregnancy ◽

Cross Sectional Study ◽

The Body ◽

Sectional Study ◽

Cross Sectional ◽

Vitamin D Levels ◽

The Mean ◽

25 Oh Vitamin D

AIM: A cross-sectional study was conducted at Saad Abualila Hospital (Khartoum, Sudan) to evaluate the vitamin D levels and thyroid function among pregnant Sudanese women (132) in early pregnancy.METHODS: A cross-sectional study was conducted at Saad Abualila hospital (Khartoum, Sudan) during the period from March to July 2015. Women who were in early pregnancy with a singleton pregnancy were approached to participate in the study after signing informed consent. A sample size of 132 participants was calculated guided by the normal interval of thyroid function in Sudanese women in the first trimester and not the level of 25(OH) vitamin D. The 25 - hydroxyvitamin D (25 (OH) vitamins levels were measured using an electrochemiluminescence immunoassay on an Elecsys 2010 Analyzer (Roche Diagnostics, Mannheim, Germany).RESULTS: The mean (SD) of age, gravidity and gestational age was 27.6 (5.5) years, 2.2 (1.6) and 10.4 (2.2) weeks, respectively. The mean (SD) of the body mass index (BMI) and haemoglobin was 27.1 (5.2) kg/m2 and 10.8 (1.1) g/dl, respectively. Median (interquartile) values of TSH, FT3, and FT4 were 1.164 IU/ml (0.079 -2.177 IU/ml), 4.639 nmol/l (3.843 - 6.562 nmol/l), and 16.86 pmol/l (13.02 - 31.48 pmol/l), respectively. There was no significant correlation between vitamin D levels and TSH, FT3 and FT4CONCLUSION: There is no correlation between 25 (OH) vitamin D levels and thyroid function during early pregnancy among Sudanese pregnant women, despite prevalent vitamin D deficiency among these women.

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Thyroid dysfunction in preeclampsia and related fetomaternal outcomes

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20191944 ◽

2019 ◽

Vol 8 (5) ◽

pp. 1928

Author(s):

Puja Banik ◽

R. K. Praneshwari Devi ◽

Aheibam Bidya ◽

Akoijam Tamphasana ◽

M. Agalya ◽

...

Keyword(s):

Thyroid Function ◽

Thyroid Dysfunction ◽

Birth Asphyxia ◽

Normal Pregnancy ◽

Thyroid Stimulating Hormone ◽

Severe Preeclampsia ◽

Intrauterine Fetal Death ◽

Overt Hypothyroidism ◽

Thyroid Function Tests ◽

Cross Sectional

Background: Changes in thyroid function in normal pregnancy are well-documented but in complicated pregnancy like preeclampsia, very little is known. Studies have shown evidences of hypothyroidism in preeclampsia necessitating thyroid function tests to be done in preeclampsia. The study was done to analyze the fetomaternal outcome of preeclampsia with coexisting thyroid dysfunction.Methods: A cross-sectional analytical study was done over 18 months on 95 preeclamptic patients admitted at the antenatal ward and fetomaternal outcomes were analyzed according to thyroid status.Results: Out of 95 patients with preeclampsia, 42 (44.2%) had thyroid dysfunction. Among these 42 patients, 37 (38.9%) patients had subclinical hypothyroidism, 4 (4.2%) had overt hypothyroidism and 1 (1%) had hyperthyroidism. Severe preeclampsia was seen in 64.3% of the patients with thyroid dysfunction compared with 39.6% in euthyroid patients. The mean thyroid stimulating hormone (TSH) level was significantly higher and means free thyroxine (fT4) level was significantly lower in severe preeclampsia compared with non-severe preeclampsia. Complications like abruption, intrauterine fetal death (IUD), intrauterine growth restriction (IUGR), oligohydramnios, preterm deliveries, postpartum hemorrhage (PPH), low birth weight babies, birth asphyxia in babies and subsequent neonatal intensive care unit (NICU) admissions were significantly higher (p <0.05) in the preeclampsia patients with thyroid dysfunction in comparison with euthyroid ones.Conclusions: Hypothyroidism may be a modifiable risk factor for preeclampsia. Thyroid screening early in pregnancy may be helpful in predicting the occurrence of preeclampsia and timely thyroid hormone administration can reduce the maternal and perinatal morbidity and mortality associated with preeclampsia.

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