Second-Trimester Reference Intervals for Thyroid Tests: The Role of Ethnicity

Abstract Background: Thyroid function changes during pregnancy, complicating the diagnosis of thyroid disorders. Maternal thyroid dysfunction has been associated with a variety of adverse outcomes. We evaluated thyroid function test results by ethnicity and week of gestation during the 2nd trimester of pregnancy. Methods: We collected 3064 blood specimens in serum tubes from Asians (13%), blacks (22%), Hispanics (23%), and whites (42%). We measured thyroid-stimulating hormone (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroglobulin autoantibodies (TgAb), and thyroid peroxidase autoantibodies (TPOAb) by use of an ARCHITECT i2000SR (Abbott Diagnostics). The TSH reference interval was calculated for samples negative for both TgAb and TPOAb and reference intervals for TT4, FT4, TT3, and FT3 in antibody-negative samples with normal TSH. Results: Serum samples were positive for TgAb in 10.6%, 1.8%, 6.2%, 6.5%, and 5.9% of Asian, black, Hispanic, white, and combined groups, respectively. Samples were positive for TPOAb in 12.4%, 4.1%, 11.8%, 12.3%, and 10.4% of the same groups, respectively. The nonparametric reference intervals for all participants were 0.15–3.11 mIU/L (TSH), 9.3–15.2 pmol/L (0.72–1.18 ng/dL; FT4), 89.0–176.3 nmol/L (6.90–13.67 μg/dL; TT4), 3.82–5.96 pmol/L (2.48–3.87 pg/mL; FT3), and 1.82–3.68 nmol/L (118–239 ng/dL; TT3). Conclusions: Blacks had lower prevalences of TgAb and TPOAb positivity and of increased serum TSH. The prevalence of TgAb and TPOAb positivity was highest in Asians. Whites had the highest prevalence of increased TSH. The lower and upper reference limits of TT3 were significantly lower for Asians. Reference intervals for women in the 2nd trimester were different from those of nonpregnant individuals.

Download Full-text

Trimester- and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

International Journal of Endocrinology ◽

10.1155/2016/3754213 ◽

2016 ◽

Vol 2016 ◽

pp. 1-5 ◽

Cited By ~ 7

Author(s):

Jinfang Xing ◽

Enwu Yuan ◽

Jing Li ◽

Yuchao Zhang ◽

Xiangying Meng ◽

...

Keyword(s):

Thyroid Function ◽

Chinese Women ◽

Reference Interval ◽

First Trimester ◽

Cross Sectional Study ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Thyroid Peroxidase ◽

American Thyroid Association ◽

Cross Sectional

Objective. The guidelines of the American Thyroid Association (ATA) recommend an upper limit reference interval (RI) of thyroid stimulating hormone (TSH) of 2.5 mIU/L in the first trimester of pregnancy and 3.0 mIU/L in subsequent trimesters, but some reported ranges in China are significantly higher. Our study aimed to establish trimester- and assay-specific RIs for thyroid hormones in normal pregnant Chinese women. Methods. In this cross-sectional study, 2540 women with normal pregnancies (first trimester, n=398; second trimester, n=797; third trimester, n=1345) and 237 healthy nonpregnant control subjects were recruited. Serum TSH, free thyroxin (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) levels were determined by automated chemiluminescence with an Immulite 2000 system (Siemens, Erlangen, Germany). After outliers were excluded, the 2.5–97.5th percentiles were used to define the RIs. Results. The RIs of thyroid function in the first, second, and third trimesters of pregnancy and in nonpregnant controls were 0.07–3.96, 0.27–4.53, 0.48–5.40, and 0.69–5.78 mIU/L for TSH and 9.16–18.12, 8.67–16.21, 7.80–13.90, and 8.24–16.61 pmol/L for FT4, respectively. Conclusion. The trimester- and assay-specific RIs of thyroid function during pregnancy differed between trimesters, which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in Henan, China.

Download Full-text

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.

Download Full-text

THYROID STATUS OF ATHLETES IN VARIOUS DISCIPLINES

Human Sport Medicine ◽

10.14529/hsm20s101 ◽

2020 ◽

Vol 20 (S1) ◽

pp. 5-12

Author(s):

R Radzhabkadiev ◽

K Vybornaya ◽

C Lavrinenko ◽

A Vasilev

Keyword(s):

Female Athletes ◽

Elite Athletes ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

High Serum ◽

Thyroid Peroxidase ◽

Thyroid Status ◽

Free Triiodothyronine ◽

Male Athletes ◽

Normal Limits

Aim. The article deals with the assessment of the thyroid status of athletes engaged in physical activity of varying intensity. Materials ant methods. 146 elite athletes involved in bobsleigh, biathlon, shooting and snowboarding participated in the study. We determined the serum concentration of thyroid stimulating hormone (TSH), free triiodothyronine (f.T3), free thyroxin (f.T4) and thyroid peroxidase antibodies (TPO-ab) with the COBAS e411 immunochemistry analyzer (Roche, Germany). The integral thyroid index ((f.T3 + f.T4)/TSH) was used for the assessment of the level of function of the thyroid proper. The conversion index of thyroxin to triiodothyronine (f.T4/ f.T3) was also studied. Results. 40 % of the bobsleigh athletes examined and 29 % of the snowboarders had high serum f.T3. The concentration of f.T4 in all examined athletes both male and female was within normal limits. Approximately 25 % of the male athletes examined had low II values. Among female athletes, 25 % of shooters and 33 % of bobsleigh athletes had low II values. In male biathletes and bobsleigh athletes, TPO-ab was 56 % higher than in shooters and snowboarders. In 43 % of bobsleigh athletes, 19 % of shooters, 10 % of biathletes and snowboarders, the content of TSH in males exceeded the reference intervals. Among females, TSH was high in 25 % of shooters and bobsleigh athletes. Conclusion. There were no statistically significant differences in the content of thyroid hormones in the compared sports groups, which can probably be explained by the activity of deiodinases at the local, intracellular level. At the same time, in a large number of respondents surveyed, the indicators of II and TPO-ab were outside the physiological norm.

Download Full-text

Relationship between Different Psoriasis Types and Thyroid Dysfunction: A Retrospective Analysis

Scanning ◽

10.1155/2021/1834556 ◽

2021 ◽

Vol 2021 ◽

pp. 1-5

Author(s):

Juan Du ◽

Chunyue Ma ◽

Runnan Wang ◽

Lanmei Lin ◽

Luhui Gao ◽

...

Keyword(s):

Psoriatic Arthritis ◽

Thyroid Function ◽

Thyroid Dysfunction ◽

Thyroid Stimulating Hormone ◽

Thyroid Peroxidase ◽

Thyroid Function Tests ◽

Free Triiodothyronine ◽

Hormone Levels ◽

Significant Difference ◽

Total Thyroxine

Objective. The aim of this study was to investigate the relationship between different psoriasis types and thyroid dysfunction. Methods. The data of patients diagnosed with psoriasis between January 2013 and October 2018 who underwent thyroid function tests were collected. Free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), total thyroxine (TT4), thyroid-stimulating hormone (TSH), thyroglobulin antibody (TGAb), and thyroid peroxidase antibody (TPOAb) were measured. The thyroid function of patients with psoriasis vulgaris, pustular psoriasis, erythrodermic psoriasis, and psoriatic arthritis was evaluated, and the differences in hormone levels and antibodies in the pituitary-thyroid axis with psoriasis type were analyzed. Results. The data of a total of 468 patients were analyzed in this study. The proportion of normal hormone levels was higher among vulgaris patients ( P < 0.001 ), while the erythrodermic patients were more likely to have decreased FT3 or FT4 but normal TSH ( P < 0.001 ). FT3 levels were lower in pustular patients ( P < 0.05 ), FT4 levels were lower in erythrodermic patients ( P < 0.05 ), and TSH levels were higher in patients with psoriatic arthritis ( P < 0.05 ). TPOAb levels were higher than normal in all patients, but there was no significant difference in the levels of TPOAb and TGAb among 4 types of the patients. Conclusion. Psoriasis is related to thyroid dysfunction, especially in patients with atypical psoriasis types. The possibility of complications should be considered in erythrodermic patients.

Download Full-text

Establishment of trimester-specific reference intervals for thyroid stimulating hormone and free thyroxine during pregnancy in southwest China by indirect method

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/00045632211063142 ◽

2021 ◽

pp. 000456322110631

Author(s):

Ying Guo ◽

Bin Wei ◽

Wei Dai ◽

Hongjian Xie

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Indirect Method ◽

Southwest China ◽

Thyroid Function Test ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Specific Reference ◽

Test Results ◽

Function Test

Objective A series of physiological changes in thyroid function occur during pregnancy and differ from those non-pregnant women. This study aimed to establish the pregnancy-specific reference intervals of TSH and FT4 using an indirect method based on the healthy pregnant women from southwest China population. Methods Thyroid function test results which available on the Laboratory Information System (LIS) were collected from the pregnancies who visited the Obstetric Clinic or the Department of Gynecology between 1 January 2015, and 30 December 2020. We grouped the data by trimesters to establish the reference intervals (RIs) based on the clinical consensus of different levels of TSH and FT4 at different weeks of gestation. All arrangements were referenced to the document CLSI EP28-A3C. Results A total of 33,040 thyroid function test results of pregnant women, aged 31 (28,33) years were statistical analyzed. Estimated RIs for TSH and FT4 in the first, second and third trimesters corresponding to the 2.5th and 97.5th percentiles in TPOAb negative were 0.02–5.23, 0.03–5.24, 0.37–5.68 mIU/L, 11.66–20.69, 10.1–18.59, 9.85–16.86pmol/L, respectively. Conclusion This study provides trimester-specific RIs for TSH and FT4 among healthy pregnant women in southwest China which guides clinicians to diagnosis and screen for thyroid disorders in this region.

Download Full-text

Thyroid evaluation of children and adolescents with Williams syndrome in Zhejiang Province

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2017-0140 ◽

2017 ◽

Vol 30 (12) ◽

Cited By ~ 4

Author(s):

Wei-Jun Chen ◽

Chai Ji ◽

Dan Yao ◽

Zheng-Yan Zhao

Keyword(s):

Children And Adolescents ◽

Thyroid Function ◽

Williams Syndrome ◽

Subclinical Hypothyroidism ◽

Thyroid Stimulating Hormone ◽

Zhejiang Province ◽

Overt Hypothyroidism ◽

Thyroid Peroxidase ◽

Thyroid Antibodies ◽

Free Triiodothyronine

AbstractBackground:The objective of the study was to describe the prevalence of abnormal thyroid function and volume in children and adolescents with Williams syndrome (WS) in Zhejiang Province, China.Methods:Thyroid function, including thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroid antibodies (thyroid peroxidase and thyroglobulin) were measured in 83 patients with WS, aged 0.2–16.5 years. Twenty-three patients were followed for an average of 1.7 years (0.4–4.1), and multiple TSH determinations were considered. Thyroid ultrasonography was performed on 49 patients.Results:One patient was diagnosed with overt hypothyroidism, and 23 patients (27%) had subclinical hypothyroidism (SH). Thyroid antibodies were absent in all patients. In five age groups (0–1 years, 1–3 years, 3–6 years, 6–9 years, 9–18 years), the prevalence of patients with subclinical hypothyroidism was 25%, 28.5%, 44.4%, 16.7% and 4.7%, respectively. Through ultrasound examination, 21 patients (42%) were observed to have thyroid hypoplasia (TH), and there were no cases of thyroid haemiagenesis. The incidence rate of TH increased with age, rising from 20% in the youngest group to 66% in the oldest.Conclusions:SH and TH is common in children and adolescents with WS. Yearly evaluation of thyroid must be performed in all patients in this population, regardless of the result of the neonatal screening. Age under 6 years and existing thyroid abnormalities are risk factors for developing SH, and a shorter follow-up interval is needed for screening in these individuals, SH is often self-limiting, and clinicians should be alert to overt hypothyroidism.

Download Full-text

First- and Second-Trimester Reference Intervals for Thyroid Hormones during Pregnancy in “Rhea” Mother-Child Cohort, Crete, Greece

Journal of Thyroid Research ◽

10.4061/2011/490783 ◽

2011 ◽

Vol 2011 ◽

pp. 1-12 ◽

Cited By ~ 16

Author(s):

Polyxeni Karakosta ◽

Leda Chatzi ◽

Emmanouil Bagkeris ◽

Vasiliki Daraki ◽

Dimitris Alegakis ◽

...

Keyword(s):

Thyroid Hormones ◽

Reference Interval ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Specific Reference ◽

Reference Ranges ◽

Thyroid Function Tests ◽

Second Trimester ◽

Free Triiodothyronine ◽

Reference Limit

Estimation and interpretation of thyroid function tests in pregnant women is of utmost importance for maternal, fetal and neonatal health. Our objective was to calculate laboratory- and geography-specific reference intervals for thyroid hormones during pregnancy in an iodine-sufficient area of the Mediterranean, Crete, Greece. This project was performed in the context of “Rhea” mother-child cohort. Fulfillment of extensive questionnaires and estimation of free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), and antithyroid antibodies were performed. The reference population was defined using inclusion criteria regarding thyroidal, obstetric, and general medical status of women. Reference interval for TSH was 0.05–2.53 μIU/mL for the first and 0.18–2.73 μIU/mL for the second trimester. 6,8% and 5,9% of women in the first and second trimester, respectively, had TSH higher than the upper reference limit. These trimester-specific population-based reference ranges are essential in everyday clinical practice for the correct interpretation of thyroid hormone values and accurate classification of thyroid disorders.

Download Full-text

The Association of Thyroid Hormone Changes with Inflammatory Status and Prognosis in COVID-19

International Journal of Endocrinology ◽

10.1155/2021/2395212 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Ceyda Dincer Yazan ◽

Can Ilgin ◽

Onur Elbasan ◽

Tugce Apaydin ◽

Saida Dashdamirova ◽

...

Keyword(s):

Thyroid Function ◽

Thyroid Autoimmunity ◽

Oxygen Demand ◽

Thyroid Stimulating Hormone ◽

Thyroid Peroxidase ◽

Thyroid Function Tests ◽

Free Triiodothyronine ◽

Icu Admission ◽

Inflammatory Status ◽

Length Of Hospitalization

Background. COVID-19 infection may have multiorgan effects in addition to effects on the lungs and immune system. Recently, studies have found thyroid function abnormalities in COVID-19 cases which were interpreted as euthyroid sick syndrome (ESS) or destructive thyroiditis. Therefore, in this study, we aimed to evaluate the thyroid function status and thyroid autoimmunity in COVID-19 patients. Material and Method. 205 patients were included. The medical history and laboratory parameters at admission were collected from medical records. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroid peroxidase antibody, and thyroglobulin antibody were measured, and patients were classified according to thyroid function status. Results. 34.1% of the patients were euthyroid. Length of hospitalization ( p < 0.001 ), rate of oxygen demand ( p < 0.001 ), and intensive care unit (ICU) admission ( p = 0.022 ) were lower, and none of the euthyroid patients died. 108 (52.6%) patients were classified to have ESS, 57 were classified as mild, and 51 were moderate. The inflammatory parameters were higher in patients with moderate ESS. In cluster analysis, a high-risk group with a lower median FT3 value (median = 2.34 ng/L; IQR = 0.86), a higher median FT4 value (median = 1.04 ng/dL; IQR = 0.33), and a lower median TSH value (median = 0.62 mIU/L; IQR = 0.59) included 8 of 9 died patients and 25 of the 31 patients that were admitted to ICU. Discussion. Length of hospitalization, oxygen demand, ICU admission, and mortality were lower in euthyroid patients. Moreover, none of the euthyroid patients died. In conclusion, evaluation of thyroid function tests during COVID-19 infection may give information about the prognosis of disease.

Download Full-text

Establishment of trimester-specific thyroid stimulating hormone and free thyroxine reference interval in pregnant Chinese women using the Beckman Coulter UniCel™ DxI 600

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2014-0615 ◽

2015 ◽

Vol 53 (9) ◽

Cited By ~ 8

Author(s):

Jing Zhang ◽

Wei Li ◽

Qiao-Bin Chen ◽

Li-Yi Liu ◽

Wei Zhang ◽

...

Keyword(s):

Chinese Women ◽

Reference Interval ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Free Thyroxine ◽

Specific Reference ◽

Thyroid Peroxidase ◽

Cross Sectional ◽

Reported Data ◽

Stimulating Hormone

AbstractThyroid-stimulating hormone (TSH) and free thyroxine (FT4) reference intervals are essential for screening and diagnosing thyroid dysfunction during pregnancy. The aim of this study was to establish method- and trimester-specific TSH and FT4 reference intervals in pregnant Chinese women using the Beckman Coulter UniCel™ DxI 600.A cross-sectional dataset analysis was performed. A total of 3507 participants were recruited, and 2743 were eligible for analysis to set reference intervals. TSH, FT4, and thyroid peroxidase antibody (TPOAb) levels were analyzed with the Beckman Coulter UniCel™ DxI 600 AccessThe calculated reference intervals for the first, second, and third trimesters were TSH: 0.06–3.13, 0.07–4.13 and 0.15–5.02 mIU/L, respectively, and FT4: 8.72–15.22, 7.10–13.55 and 6.16–12.03 pmol/L, respectively.Our reference intervals for TSH and FT4 are distinct from the ranges reported in the DxI 600 instruction manual and previously reported data, confirming the importance of method-specific reference intervals.

Download Full-text

First- and Second-Trimester Reference Intervals for Thyroid Function Testing in a US Population

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa165 ◽

2020 ◽

Author(s):

Dustin R Bunch ◽

Kyle Firmender ◽

Roa Harb ◽

Joe M El-Khoury

Keyword(s):

Thyroid Function ◽

The United States ◽

Reference Intervals ◽

Adverse Outcomes ◽

Specific Reference ◽

Thyroid Peroxidase ◽

Thyroid Function Tests ◽

Second Trimester ◽

Function Tests ◽

Increased Risk

Abstract Objectives Thyroid dysfunction in pregnancy is associated with increased risk of adverse outcomes to mother and child. Trimester-specific reference intervals for thyroid function tests are not routinely provided by clinical laboratories. In this study, we present first- and second-trimester-specific reference intervals in a US population for thyroid-stimulating hormone (TSH), free thyroxine (FT4), total thyroxine (T4), and total triiodothyronine (T3) measured on Roche analyzers. Methods We used patient samples from first- and second-trimester prenatal screening. Samples were limited to singleton pregnancies and negative screening results for thyroid peroxidase and thyroglobulin antibodies. Analytes (TSH, FT4, T4, and T3) were measured on a Roche Modular e170 then verified on a Roche cobas e801. Results The reference intervals established on the e170 and verified on the e801 for the first trimester were 0.11 to 3.48 mIU/L for TSH, 11.2 to 19.0 pmol/L for FT4, 51.1 to 185.6 nmol/L for T4, and 1.4 to 3.5 nmol/L for T3. The reference intervals for the second trimester were 0.31 to 3.85 mIU/L for TSH, 9.4 to 16.5 pmol/L for FT4, 55.1 to 174.0 nmol/L for T4, and 1.5 to 3.7 nmol/L for T3. Conclusions This is the first report of trimester-specific reference intervals for thyroid function tests on Roche analyzers in the United States, and it is consistent with worldwide reports.

Download Full-text