scholarly journals Lower Normal Thyroid Function is Associated With a Higher Risk of Metabolic Syndrome: A Retrospective Cohort on Chinese Population

2020 ◽  
Author(s):  
Xi Ding ◽  
Chunying Zhu ◽  
Rui Li ◽  
Liping Wu ◽  
Yue Wang ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Thyroid Function ◽  
Heart Association ◽  
Health Examination ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Cutoff Values ◽  
Significant Difference

Abstract BackgroundRecently, the relationship between thyroid hormones (THs) across the euthyroid ranges and metabolic syndrome (MetS) has been widely discussed. This study aimed to present specific cutoff values of THs to assess the association between THs and MetS in a euthyroid cohort.MethodsData of 2694 subjects, aged 18-80 years, who attended health examination in Xi’an Electric Power Central Hospital from April 2011 to December 2015 were collected and analyzed. The basic cohort enrolled 929 participants (followed up by 2221 person-years totally) to assess correlations between serum thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4) levels and MetS. The second cohort included 698 participants (followed up by 1709 person-years totally) to evaluate relationships between serum free triiodothyronine (FT3), free thyroxine (FT4) levels and MetS. MetS was defined according to the criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) scientific statements of 2009. Euthyroidism was defined as serum TSH, FT3 and FT4 levels within the reference ranges without taking any thyroid medication.ResultsThe cutoff values for TSH, T3, T4, FT3 and FT4 were 2.0mIU/L, 1.9nmol/L, 117nmol/L, 4.3pmol/L and 16pmol/L, respectively. Participants were categorized into two groups according to cutoff values: the lower-THs group and the higher-THs group. There was no significant difference in the risk of MetS between two groups in TSH, T3, T4 and FT3. The incidence of MetS was significantly higher in lower-FT4 group than higher-FT4 group (1.00 vs 0.622 (0.458, 0.846), P=0.002). The lower-FT4/higher-TSH group had the highest hazard ratios of MetS. (2.131vs 1.0 (1.380,3.291), P=0.006)ConclusionsLower normal FT4 (FT4≤16.0 pmol/L) is an independent risk factor for MetS, and lower normal thyroid function (TSH>2.0 mIU/L and FT4≤16.0 pmol/L) is associated with a higher risk of developing MetS.

scholarly journals Lower normal free thyroxine is associated with a higher risk of metabolic syndrome: a retrospective cohort on Chinese population

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xi Ding ◽  
Chun-Ying Zhu ◽  
Rui Li ◽  
Li-Ping Wu ◽  
Yue Wang ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Heart Association ◽  
Free Thyroxine ◽  
Health Examination ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Blood Institute ◽  
Normal Thyroid Function ◽  
Cutoff Values ◽  
Significant Difference

Abstract Background Recently, the relationship between thyroid hormones (THs) across the euthyroid ranges and metabolic syndrome (MetS) has been widely discussed. This study aimed to present specific cutoff values of THs to assess the association between THs and MetS in a euthyroid cohort. Methods Data of 2694 subjects, aged 18–80 years, who attended health examination in Xi’an Electric Power Central Hospital from April 2011 to December 2015 were collected and analyzed. The first cohort enrolled 929 participants (followed up by 2221 person-years totally) to assess correlations between serum thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4) levels and MetS. The second cohort included 698 participants (followed up by 1709 person-years totally) to evaluate relationships between serum free triiodothyronine (FT3), free thyroxine (FT4) levels and MetS. MetS was defined according to the criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) scientific statements of 2009. Euthyroidism was defined as serum TSH, FT3 and FT4 levels within the reference ranges without taking any thyroid medication. Results The cutoff values for TSH, T3, T4, FT3 and FT4 were 2.0mIU/L, 1.9 nmol/L, 117 nmol/L, 4.3 pmol/L and 16 pmol/L, respectively. Participants were categorized into two groups according to cutoff values: the lower-THs group and the higher-THs group. There was no significant difference in the risk of MetS between two groups in TSH, T3, T4 and FT3. The incidence of MetS was significantly higher in lower-FT4 group than higher-FT4 group (1.00 vs 0.622 (0.458, 0.846), P = 0.002). The lower-FT4/higher-TSH group had the highest hazard ratios of MetS. (2.131vs 1.0 (1.380,3.291), P = 0.006). Conclusions Lower normal FT4 (FT4 ≤ 16.0 pmol/L) is an independent risk factor for MetS, and lower normal thyroid function (TSH > 2.0 mIU/L and FT4 ≤ 16.0 pmol/L) is associated with a higher risk of developing MetS.

P3414Differences in total life expectancy and life expectancy with and without non-communicable diseases within the reference range of thyroid function

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Bano ◽  
L Chaker ◽  
F U S Mattace-Raso ◽  
R P Peeters ◽  
O H Franco
Keyword(s):  
Life Expectancy ◽  
Thyroid Function ◽  
Communicable Diseases ◽  
Reference Ranges ◽  
Men And Women ◽  
Non Communicable Diseases ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Total Life Expectancy ◽  
The Impact

Abstract Background Variations in thyroid function within the reference ranges are associated with an increased risk of diseases and death. However, the impact of thyroid function on life expectancy (LE) and the number of years lived with and without non-communicable diseases (NCD) remains unknown. Purpose We aimed to investigate the association of thyroid function with total LE and LE with and without NCD among euthyroid subjects. Methods Participants of the Rotterdam Study without known thyroid disease and with thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels within the reference ranges were eligible. NCD were defined as the presence of cardiovascular disease, diabetes mellitus type 2, or cancer. We used multistate life tables to calculate the total LE and LE with and without NCD among TSH and FT4 tertiles, in men and women. LE estimates were obtained using prevalence, incidence rates and hazard ratios for three transitions (healthy to NCD, healthy to death and NCD to death). Analyses were adjusted for sociodemographic and cardiovascular risk factors. Results The mean (standard deviation) age of 7644 participants was 64.5 (9.7) years and 52.2% were women. Over a median follow-up of 8 years, we observed 1396 incident NCD events and 1422 deaths. Compared with those in the lowest tertile, men and women in the highest TSH tertile lived 1.5 (95% confidence interval [CI], 0.8; 2.3) and 1.5 (95% CI, 0.8; 2.2) years longer, respectively; of which 1.4 (95% CI, 0.5; 2.3) and 1.3 (95% CI, 0.3; 2.1) years with NCD. Compared with those in the lowest tertile, the difference in LE for men and women in the highest FT4 tertile was −3.7 (95% CI, −5.1 to −2.2) and −3.3 (95% CI, −4.7; −1.9), respectively; of which −1.8 (95% CI, −3.1 to −0.7) and −2.0 (95% CI, −3.4 to −0.7) years without NCD. Life expectancy in TSH and FT4 tertiles Conclusions There are meaningful differences in total LE, LE with and without NCD within the reference ranges of thyroid function. People with low-normal thyroid function live more years with and without NCD than those with high-normal thyroid function. These findings support a reevaluation of the current reference ranges of thyroid function.

The Effect of Metformin on Thyroid-Associated Serum Hormone Levels and Physiological Indexes: A Meta-Analysis

2019 ◽  
Vol 25 (30) ◽  
pp. 3257-3265 ◽  
Author(s):  
Junjie Wang ◽  
Jinghan Gao ◽  
Qin Fan ◽  
Hongzhuo Li ◽  
Yunhua Di
Keyword(s):  
Blood Pressure ◽  
Thyroid Function ◽  
Metformin Treatment ◽  
Free Triiodothyronine ◽  
Lower Serum ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Physiological Indices ◽  
Serum Tsh ◽  
Tsh Levels

Background: Many diseases can be treated with metformin. People with serum thyrotropin (TSH) levels higher than 10 mIU/L are at a risk of cardiovascular events. Some studies have suggested that metformin can lower serum TSH levels to a subnormal level in patients with hyperthyrotropinaemia or hypothyroidism. Objective: The objective of this analysis is to evaluate the effect of metformin treatment on serum TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels and other associated physiological indices. Methods: A comprehensive search using the PubMed, EMBASE, Web of Science and Cochrane Central databases was undertaken for controlled trials on the effect of metformin on serum TSH, FT3, and FT4 levels and associated physiological indices. The primary outcome measures were serum TSH, FT3 and FT4 levels, thyroid size, thyroid nodule size, blood pressure, heart rate, body weight, and body mass index (BMI). The final search was conducted in April 2019. Results: Six RCTs were included. A total of 494 patients met the inclusion criteria. Metformin treatment did not significantly lower the serum TSH levels at 3 or 6 months but did at 12 months. Moreover, forest plots also suggested that metformin can significantly lower the serum TSH levels in patients with normal thyroid function but cannot statistically change the serum TSH levels in patients with abnormal thyroid function. In addition, metformin treatment clearly lowered the serum FT3 levels and had no significant effect on serum FT4 levels. Lastly, metformin cannot significantly change the systolic blood pressure (SBP) or BMI but can clearly increase the diastolic blood pressure (DBP). Conclusion: Metformin treatment can significantly lower the serum TSH levels, and this effect was much clearer after a 12-month treatment duration and in people with normal thyroid function. However, metformin cannot significantly change the serum FT4 levels or lower serum FT3 levels in people with non-thyroid cancer diseases. In addition, metformin can significantly increase DBP, but it has no clear effect on SBP or BMI.

Quantification of the negative feedback mechanism between pituitary and thyroid in subjects with normal thyroid function

1996 ◽  
Vol 135 (3) ◽  
pp. 316-321
Author(s):  
Karin Sydow ◽  
Dieter Emrich ◽  
Olaf Gefeller ◽  
Inge Schreivogel
Keyword(s):  
Thyroid Function ◽  
Negative Feedback ◽  
Group Analysis ◽  
Feedback Mechanism ◽  
Control Group ◽  
Free Triiodothyronine ◽  
Normal Thyroid ◽  
Negative Feedback Mechanism ◽  
Normal Thyroid Function ◽  
University Of Göttingen

Sydow K, Emrich D, Gefeller O, Schreivogel I. Quantification of the negative feedback mechanism between pituitary and thyroid in subjects with normal thyroid function. Eur J Endocrinol 1996;135:316–21. ISSN 0804–4643 Using sufficiently sensitive and precise assays, we systematically investigated the correlation between thyrotropin, thyroglobulin, index of free thyroxine and index of free triiodothyronine after different doses of thyroxine (25, 50, 100, 150 μg), which were administered daily for 10 days to individuals with normal thyroid function and in a control group. Analysis of the data using relative median values expressing changes to basal values before administration of thyroxine yielded the following results: (i) thyrotropin and thyroglobulin decreased monoexponentially, depending on the doses of thyroxine administered; (ii) the extent of their decrease showed a linear correlation with the dose of thyroxine administered and was greater for thyrotropin than for thyroglobulin; (iii) the relative velocity of their decrease increased monoexponentially with the dose of thyroxine and did not differ between thyrotropin and thyroglobulin. These results provide strong evidence for a clear quantitative reaction of the feedback mechanism and confirm that the secretion of thyroglobulin is a physiological process dependent on thyrotropin. The high intra-individual variations obtained for thyrotropin were probably due to its pulsatile secretion. D. Emrich, Department of Nuclear Medicine, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany

scholarly journals Relationship between thyroid hormones and metabolic syndrome in a normal thyroid function population in Western China

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Sheng-Ru Liang ◽  
Jing Cai ◽  
Yang Yang ◽  
Lei Zhang ◽  
Peter Taylor ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Western China ◽  
Normal Thyroid ◽  
Normal Thyroid Function

scholarly journals High Prevalence of Anti Thyroid Antibodies in an Albanian Cohort of Patients

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A830-A831
Author(s):  
Dorina Minxuri ◽  
Anila Mitre ◽  
Silva Bino ◽  
Ina Toska ◽  
Ina Mulla
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Thyroid Dysfunction ◽  
Thyroid Disorders ◽  
Thyroid Antibodies ◽  
Positive Group ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Significant Difference ◽  
High Prevalence

Abstract Introduction: Albania is classified as iodine deficient region and endemic goiter in this country has been a concern for public health. A salt iodization program has been implemented in Albania since 2008. Most of regions still remain with a mild or moderate iodine deficiency there are no studies on prevalence of thyroid autoimmune disorders. The purpose of this study was to assess thyroid function and the presence of thyroid antibodies in subjects that were not previously diagnosed or treated for thyroid disorders. Methods: This is a cross-sectional study performed in a cohort of patients in Albania during a 2 year period (january 2018-january 2020). We assessed the prevalence of thyroid function disorders and presence of thyroid antibodies in 5047 subjects (81% females and 19% males). Individuals previously diagnosed or treated for thyroid disease were excluded from the study. TSH, Free T4, total T3, Anti TPO(thyroid peroxidase) and anti TG (thyroglobulin) were measured with electrochemiluminescence method with Cobas 6000 Roche Diagnostics. We calculated the frequency of thyroid antibodies and the abnormal thyroid function. Statistical analysis was performed to see if there was a difference between individuals with positive antibodies and those negative for antibodies. Results: 91 % (4596) of subjects resulted euthyroid. We found a low prevalence of overt thyroid dysfunction (hyperthyroidism 0.48% and hypothyroidism 1.69%). The rates of subclinical hypothyroidism and hyperthyroidism were 5.5% and 1.4% respectively. The prevalence of positive thyroid antibodies, at least one of them was 28% in females and 14% in males (2:1 ratio). 97.3 % of subjects who testet negative for antibodies had normal thyroid function compared to 73.5% in antibodies positive group. There was a significant difference for subclinical hypothyroidism and other thyroid disorders between antibodies positive group and antibodies negative group (p value <0.0000119% of individuals(from 5047 examined) had normal thyroid function and resulted positive for anti TPO or anti TG. Conclusions: Undiagnosed biochemical thyroid dysfunctions were common in subjects living in a mild to moderate iodine-deficient area especially subclinical hypothyroidism. TSH level correlated well with the presence of antibodies resulting in significant difference in thyroid function between 2 groups. We found a high prevalence (19%) of thyroid antibodies in euthyroid subjects. TPO antibodies in euthyroid subjects can be used to identify subjects with increased risk for hypothyroidism such as women who are pregnant (to predict first trimester or postpartum thyroid dysfunction), patients with other autoimmune diseases, subjects on drugs like amiodarone or relatives of patients with autoimmune thyroid diseases.

Radioiodine treatment of feline hyperthyroidism in Germany

2002 ◽  
Vol 41 (06) ◽  
pp. 245-251 ◽  
Author(s):  
M. Knietsch ◽  
T. Spillmann ◽  
E.-G. Grünbaum ◽  
R. Bauer ◽  
M. Puille
Keyword(s):  
Radiation Exposure ◽  
Radiation Protection ◽  
Thyroid Function ◽  
Radioiodine Therapy ◽  
Whole Body ◽  
Radioiodine Treatment ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Body Activity ◽  
Thyroid Uptake

SummaryAim: Establishment of radioiodine treatment of feline hyperthyroidism in veterinary routine in accordance with German radiation protection regulations. Patients and methods: 35 cats with proven hyperthyroidism were treated with 131I in a special ward. Thyroid uptake and effective halflife were determined using gammacamera dosimetry. Patients were released when measured whole body activity was below the limit defined in the German “Strahlenschutzverordnung”. Results: 17/20 cats treated with 150 MBq radioiodine and 15/15 cats treated with 250 MBq had normal thyroid function after therapy, normal values for FT3 and FT4 were reached after two and normal TSH levels after three weeks. In 14 cats normal thyroid function was confirmed by controls 3-6 months later. Thyroidal iodine uptake was 24 ± 10%, effective halflife 2.5 ± 0.7 days. Whole body activity <1 MBq was reached 13 ± 4 days after application of 131I. Radiation exposure of cat owners was estimated as 1.97 Sv/MBq for adults. Conclusion: Radioiodine therapy of feline hyper-thyroidism is highly effective and safe. It can easily be performed in accordance with German radiation protection regulations, although this requires hospitalisation for approximately two weeks. Practical considerations on radiation exposure of cat owners do not justify this long interval. Regulations for the veterinary use of radioactive substances similar to existing regulations for medical use in humans are higly desirable.

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