Decrease In Thyroid-stimulating Hormone Levels Research Articles

Clinical Evaluation of a Novel, Patented Green Coffee Bean Extract (GCB70®), Enriched in 70% Chlorogenic Acid, in Overweight Individuals

Objective Obesity and overweight are challenging health problems of the millennium that lead to diabetes, hypertension, dyslipidemia, nonalcoholic fatty liver disease (NAFLD), and atherosclerosis. Green coffee bean exhibited significant promise in healthy weight management, potentiating glucose-insulin sensitization and supporting liver health. The safety and efficacy of a novel, patented water-soluble green coffee bean extract (GCB70® enriched in 70% total chlorogenic acid and <1% caffeine) was investigated in 105 participants for 12 consecutive weeks. An institutional review board and Drugs Controller General (India) (DCGI) approvals were obtained, and the study was registered at ClinicalTrials.gov. Method Body weight, body mass index (BMI), waist circumference, lipid profile, plasma leptin, glycosylated hemoglobin (HbA1c), and total blood chemistry were assessed over a period of 12 weeks of treatment. Safety was affirmed. Results GCB70 (500 mg BID) supplementation significantly reduced body weight (approximately 6%; p = 0.000**) in approximately 97% of the study population. About a 5.65% statistically significant reduction (p = 0.000**) in BMI was observed in 96% of the study volunteers. Waist circumference was significantly reduced by 6.77% and 6.62% in 98% of the male and female participants, respectively. Plasma leptin levels decreased by 13.6% in 99% of the study population as compared to the baseline value. Upon completion of 12 weeks’ treatment, fasting glucose levels decreased by 13.05% (p = 0.000**) in 79% of the study population. There was a statistically significant decrease in HbA1c levels in both male and female participants (p = 0.000**), while 86.7% of the study participants showed a statistically significant decrease in thyroid-stimulating hormone (TSH) levels (p = 0.000**). The mean decrease in TSH levels on completion of the treatment was 14.07% in the study population as compared to baseline levels. Total blood chemistry analysis exhibited broad-spectrum safety. Conclusions This investigation demonstrated that GCB70 is safe and efficacious in healthy weight management.

Subclinical Hypothyroidism and Functional Hemodynamics of the Heart

Subclinical hyperthyroidism (SHyper), a laboratory decrease in thyroid-stimulating hormone levels with peripheral thyroid hormone levels within the reference interval, is considered a medical condition, especially its impact on cardiac hemodynamics among young women. To determine the effects of subclinical thyroid dysfunction on hemodynamics in young women. clinical observation included two groups of women: (1) the main group consisted of 30 patients with subclinical hyperthyroidism, which was examined at the Family Medicine Clinic of the West Kazakhstan Marat Ospanov Medical University (Aktobe, Kazakhstan) and (2) the control group consisted of 30 practically healthy women. The groups were comparable in age (30–42), mean age 36.2±7.0 years. Blood pressure (BP) was measured, heart rate (HR) was counted, and thyroid hormones were determined. in the examined patients, clinical symptoms of pathology were not observed; laboratory tests determined a decrease in thyroid-stimulating hormone (TSH) in the main group of patients to 2.48±0.23 mIU/L in comparison with the control group 3.65±1.3 mIU/L, which was significant (p0.05) increase in blood pressure SBP/DBP from 122.34±2.7/78.3±2.7 to 127.8±3.1/83.2±2.1 mmHg and HR from 77.7±1.9 to 82.2±2.6 in 1 minute. A significant (r2 =0.482) interaction was determined between TSH -0.236 mIU/L and HP +20.3 in 1 minute, this could be a predictor of an increase in heart rate greater than the reference value (60–80 per minute), and an increased heart rate is considered a predictor of an increase in blood pressure. Subclinical hyperthyroidism may produce a significant laboratory decrease in TSH, without significant clinical symptoms of increased blood pressure. In conclusion, current observational experience suggests that small decreases in laboratory values of thyroid-stimulating hormone may affect blood pressure and heart rate.

Effect of Occupational exposure to Gasoline on Reproductive and Thyroid hormones among male Petrol station attendants in Kwara State

Introduction: Petrol fume contain organic compounds that have been suggested to be endocrine disruptors. There is paucity of data on petrol fume-linked health challenges in Nigeria. Thus, we evaluated the effects of petrol fume exposure on blood levels of reproductive and thyroid hormones among petrol pump station attendants in Kwara state, Nigeria.&#x0D; Material and Methods: Eighty (80) petrol station attendants and fifty (50) non-occupationally exposed subjects were recruited as controls. Anthropometric indices were taken and fasting blood samples were collected after signing the consent form. Free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), testosterone, follicle stimulating hormone and luteinizing hormone were evaluated using standard techniques.&#x0D; Results: Average age and BMI of petrol fume-exposed subjects are 27.40±0.419 and 24.98±0.254 respectively and was not different from controls. Elevated FT3 and FT4 were evaluated with a decreased TSH level in the exposed group when compared with controls. In contrast, FSH, LH and testosterone were significantly reduced in exposed group when compared with control.&#x0D; Conclusion: The result of this study shows that petrol fume toxicants adversely alter thyroid and gonadal functions thereby modulating circulating levels of reproductive and thyroid hormones in male petrol station attendants in Kwara state.

Changes in Urinary Iodine Levels Following Bariatric Surgery

ObjectiveObesity has become an epidemic in the United States. Although bariatric surgery can effectively achieve weight loss by altering the gastrointestinal tract, it commonly results in micronutrient deficiency, requiring supplementation. Iodine is an essential micronutrient for the synthesis of thyroid hormones. We aimed to investigate changes in urinary iodine concentrations (UIC) in patients following bariatric surgery. Methods85 adults who underwent either laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass surgery were enrolled. At baseline and 3 months after surgery, we evaluated spot UIC and serum thyroid stimulating hormone (TSH), vitamin D, vitamin B12, ferritin, and folate levels. Participants provided a 24-hour diet recall for iodine-rich foods and information about multivitamin use at each time point. ResultsThere was a significant increase in median UIC (201 [120.0 – 288.5] vs 334.5 [236.3 – 740.3] μg/L; P < .001), a significant decrease in mean body mass index (44.0 ± 6.2 vs 35.8 ± 5.9; P < .001) and a significant decrease in TSH levels (1.5 [1.2 – 2.0] vs 1.1 [0.7 – 1.6] uIU/mL; P < .001) at 3 months postoperatively compared to baseline. Body mass index, UIC, and TSH levels before and after surgery did not differ based on the type of weight loss surgery. ConclusionIn an iodine-sufficient area, bariatric surgery does not cause iodine deficiency nor clinically significant changes in thyroid function. Different surgical procedures with different anatomical alterations in the gastrointestinal tract do not significantly affect iodine status.

#4846 ROXADUSTAT-INDUCED HYPOTHYROIDISM: THE EFFECT OF ROXADUSTAT ON SUPPRESSION OF THYROID FUNCTION

Abstract Background and Aims There have been only two case reports of hypothyroidism in patients treated with roxadustat, a HIF-PH inhibitor as new renal anemia drug. However, there has yet been no studies to examine the effect of roxadustat on thyroid function. Method In this study, we retrospectively examined the effects of roxadustat on thyroid-stimulating hormone (TSH) in hemodialysis patients by two blood examinations, before and during treatment with roxadustat. We included patients who had TSH levels measured after at least two consecutive weeks of roxadustat treatment and before. We excluded patients with a history of taking other HIF-PH inhibitors before roxadustat. The period was from September 2021 to November 2022 in this interim analysis. A p value of&amp;lt;0.05 was considered statistically significant. Analyses were performed using SPSS. Results 93 patients were included in this analysis. TSH levels significantly decreased after treatment with roxadustat. A total of 58.1% of patients had decreased TSH levels (2.23 ± 1.18 v.s. 1.81 ± 1.35, μIU/mL, p value = 0.040, Wilcoxon signed-rank test), and 18.3% of patients had a significant decrease below the normal range. Additionally, patients treated with thyroid hormone replacement therapy in primary hypothyroidism had a higher frequency (81.0%) of TSH decrease compared to patients without (p value = 0.013, Pearson's chi-square test). Conclusion This is the first study to examine that roxadustat has a suppressive effect on TSH secretion in hemodialysis patients. We also found that roxadustat-induced hypothyroidism is prevalent in the high frequency of TSH suppression, especially in primary hypothyroidism patients treated with thyroid hormone replacement therapy. Thyroid hormone receptor beta (THRβ), which is expressed in the hypothalamus and pituitary gland, plays an important role in regulating thyroid hormone through feedback mechanisms. Yao et al. have reported that roxadustat has a similar structure to T3 and acts as a THRβ-selective ligand, particularly activating THRβ. Therefore, it is possible that roxadustat suppresses TSH secretion through negative feedback via THRβ. It is important to monitor thyroid function in patients receiving roxadustat. Roxadustat should be avoided in patients with primary hypothyroidism, since it is inferred that roxadustat-induced hypothyroidism cannot be improved by enhancement of thyroid hormone replacement therapy.

Study of thyroid function among COVID-19-affected and non-affected people during pre and post-vaccination.

The novel coronavirus COVID-19 has caused a global pandemic with many long-ranging effects on the physiological balance of the human body. The impact of COVID-19 on the thyroid axis remains uncertain. Our aim was to assess the long-term consequences of COVID-19 infection and its vaccination with thyroid hormones. Thirty laboratory-confirmed COVID-19-positive patients with no vaccination record, thirty COVID-19-negative patients with vaccination records, and ten healthy subjects were retrospectively, and cross-sectionally enrolled in this study. An ELISA assay was performed to evaluate thyroid function tests, including the total triiodothyronine (TT3), total thyroxine (TT4), and thyroid stimulating hormone (TSH). We found decreased levels of TT3, average or low plasma T4 levels, and standard or slightly decreased TSH levels in unvaccinated COVID-19-positive patients than in the healthy group, while the vaccinated COVID-19-negative group had normal thyroid hormone levels compared to controls. The correlation between TT3 and TSH levels gradually shifted from no association to a negative pattern in the unvaccinated COVID-19-positive group. Again, a highly significant negative correlation between TSH and TT3 was observed on days above 150, although a slight fluctuation was noted on day 90. This pilot study from Bangladesh shows that abnormalities in thyroid function can be observed during COVID-19 infection and after vaccination, which gradually recovers over time.

Serum TSH, 25(OH) D and phosphorus levels predict weight loss in individuals with diabetes/prediabetes and morbid obesity: a single-center retrospective cohort analysis

BackgroundTo evaluate the association of vitamin D and thyroid-stimulating hormone (TSH) with weight loss (WL) percentage (%) in patients with diabetes/prediabetes and Class II/III obesity.MethodsA retrospective cohort study was designed. Data were collected from a database of a referral endocrinology clinic that is prospectively and systematically generated. After exclusion of unavailable cases, the study enrolled 285 patients (51 ± 11 years old, female/male = 208/77; diabetes/prediabetes = 159/126; no/on levothyroxine replacement = 176/109; Class II/III obesity = 184/101, respectively) who maintained euthyroidism and were followed up for ≥6 months. The data were analyzed to determine the predictors of WL%.ResultsCompared with baseline, in the median 22 months of follow-up, the whole study group lost 5.1% of their baseline body weight. As most obesity management trials define success as ‘at least 10% of WL compared to baseline’, we stratified the patients based on WL% extents. The distribution was as follow: Group 1 (n = 61) lost ≥10% body weight, Group 2 (n = 162) lost < 10% body weight, while Group 3 (n = 62) gained weight by the final visit. In groups 1 and 2 (weight losers), the serum thyroid stimulatig hormone (TSH) and parathyroid hormone (PTH) levels decreased and the free thyroxine (fT4), calcium, phosphorus, and 25-hydroxyvitamin D (25(OH)D) levels increased. In Group 3 (weight gainers), these changes were not observed (except for an increase in calcium levels). Regression analysis revealed that the final visit TSH (β = − 0.14, p < 0.05), 25(OH) D (β = 0.15, p < 0.05), and phosphorus (β = 0.20, p < 0.05) levels predicted WL%. However, if patients with autoimmune thyroiditis were excluded from the analysis, the decrease in TSH levels was not statistically significant.ConclusionsSerum TSH, phosphorus, and 25(OH) D levels predict WL% in euthyroid patients with diabetes/prediabetes and morbid obesity. TSH predictivity seems to be a function of thyroid autoimmunity present with increased frequency in this cohort. Greater levels of phosphorus within the reference range and a sufficient vitamin D status are associated with a greater WL%.

Studying the Association Between Systolic Blood Pressure and Thyroid Stimulating Hormone in Newly Diagnosed Subclinical Hyperthyroidism Female Patients

Background: Subclinical hyperthyroidism is a condition in which thyroid stimulating hormone (TSH) is mildly decreased with both free iodine thyroxine (free T4) and triiodothyronine (T3) within the normal range. The aim of this research is to determine the association between TSH with lipid profiles, age, blood pressure and body mass index (BMI) and also to evaluate lipid profiles in subclinical hyperthyroid patients. Materials and Methods: Ninety patients with subclinical hyperthyroidism were chosen as the patient group and 50 healthy individuals age-matched were chosen as the control group. Thyroid function tests TSH, T4 and T3 were performed by VIDAS and on the same day lipid profiles were performed by (Biolis 24i Premium) in the laboratory of General Zakho Hospital, Kurdistan Region, Iraq. Results: In subclinical hyperthyroidism the BMI and diastolic blood pressure values were non-significantly low (P=0.13 and p=0.27 respectively) whereas systolic blood pressure increased slightly but was still non-significant. TSH was significantly and negatively related to systolic blood pressure. Conclusion: Lipid profiles and systolic and diastolic blood pressure are not altered in subclinical hyperthyroidism. However, systolic blood pressure is related to the severity of the decrease in TSH levels.

Effect of Liraglutide on Serum TSH Levels in Patients with NAFLD and its Underlying Mechanisms.

This study aimed to evaluate the effect of liraglutide on serum thyroid-stimulating hormone (TSH) levels in patients with type 2 diabetes mellitus (T2DM) and explore the underlying mechanisms via bioinformatics analysis. A total of 49 obese/overweight patients with T2DM received liraglutide during outpatient visits or hospitalization in the Department of Endocrinology. Meanwhile, the control group included 49 patients with T2DM but without nonalcoholic fatty liver disease (NAFLD) who were matched for age and sex (baseline from July 2016 to June 2021). Follow-up data on the last use of liraglutide were also retrieved. Age, sex, body mass index (BMI), and duration of diabetes were obtained from the participants' records. All patients were tested for biochemical markers hemoglobin A1c (HbA1c), alanine transaminase, aspartate transaminase, free triiodothyronine, free thyroxine (FT4), and TSH at baseline and follow-up. After adjusting for all factors with a p-value < 0.05, BMI, HbA1c, LDL, FT4, and TSH were identified as significant independent risk factors for NAFLD in the univariate analysis. Following liraglutide therapy (average time 16 months), these patients had significantly lower BMI, HbA1c, and TSH but higher high-density lipoprotein (HDL) levels than those in the baseline data (all p < 0.05), and further subgroup analysis stratified by duration of liraglutide use showed that the test for time trends had statistical differences in BMI and TSH but not in HbA1c and HDL. After the therapy, the NAFLD and NASH groups showed significantly decreased TSH levels after liraglutide therapy compared with the corresponding baseline data. Furthermore, the expression of THRB, which encodes TRβ, was significantly decreased in the NAFLD group, which may explain the thyroid hormone resistance-like manifestation in the clinical findings. In conclusion, liraglutide improves hepatic thyroid hormone resistance in T2DM with NAFLD, and restoration of impaired TRβ expression in NAFLD is a potential mechanism involved in the process of liraglutide therapy.

Effects of Rehmannia 14 on Hormone Levels and Renal Function in Geriatric and Kidney Yang Deficiency Mice

The objective of this study was to investigate Rehmannia 14 (R14), a Chinese herbal medicine, reported to be effective in treating endocrine and renal function disorders in geriatric and Kidney Yang Deficiency cases. Using a geriatric and Kidney Yang Deficiency mouse model (GKDM) with a control group, 60 male Kunming mice expressing clinical signs of GKDM (weight loss, lethargy, cool limbs, decreased rectal temperature) were treated with R14 to investigate its impact on serum concentrations of triiodothyronine (T3), tetraiodothyronine (T4), thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), cortisol (COR), creatinine (CRE), blood urea nitrogen (BUN) and the content of nitric oxide (NO) in renal homogenates. Study results demonstrated that GKDM model mice had decreased body weight/rectal temperatures and lethargy while R14 treated animals had improved weight gains/normal rectal temperature and improved activity levels. The GKDM mice also had decreased T3/T4/ACTH with increased TSH while the R14 dosed animals had increased T3/T4/ACTH and decreased TSH levels. In addition, R14 exerted protective effects on the kidneys with decreased NO, CRE and BUN concentrations. Study findings concluded that R14 improved serum concentrations of key endocrine indicators of disorders of the hypothalamic-pituitary-adrenal axis and has a protective effect on renal function in a GKDM mouse model. The findings from this study provide a basis for the clinical use of R14 in the treatment of endocrine and renal disorders associated with aging and Kidney Yang/Qi Deficiency in animals.

New Reference Values for Thyroid Volume and a Comprehensive Assessment for Influencing Factors in Chinese Adults with Iodine Sufficiency

Objectives: The reference values for thyroid volume (Tvol) determined by ultrasound require supportive data of normal Tvol from local iodine-sufficient populations. This study aimed to explore new reference values for Tvol in Chinese adults and comprehensively evaluate the factors associated with enlarged Tvol. Methods: A cross-sectional study was conducted in Tianjin, China. Tvol was measured by ultrasound in adults with long-term iodine sufficiency. Blood and urine samples were collected to evaluate biochemical indexes, thyroid function, and iodine status. Results: A total of 1,991 adults from the urban and suburban areas were analysed. The trend of Tvol increasing with age was observed in men under age 40 years and in women under age 52 years. In the quantile regression analyses, we found that body surface area (BSA) (β = 7.22, 95% CI: 5.33, 9.12), thyroid-stimulating hormone (TSH) (β = −1.48, 95% CI: −2.39, −0.57), thyroid nodules (TNs) (β = 6.70, 95% CI: 2.19, 11.22), and metabolic syndrome (MetS) (β = 1.40, 95% CI: 0.63, 2.17) had a strong effect on Tvol at higher percentiles in males. The dominant factors influencing Tvol were BSA (β = 9.64, 95% CI: 2.66, 16.61), TSH (β = −0.78, 95% CI: −1.16, −0.39), and TNs (β = 1.11, 95% CI: 0.43, 1.79) in females. The largest reference values for Tvol based on BSA were 20.18 (17.79, 24.32) mL in males and 15.31 (14.05, 16.70) mL in females. Conclusions: Quantile regression analyses showed that a high BSA index, a decreased TSH level, and the prevalence of TNs were essential factors associated with the enlargement of the thyroid gland. Our findings reported the new reference values for Tvol determined by ultrasound based on gender and BSA in Chinese adults.

Effects of oral versus transdermal estradiol plus micronized progesterone on thyroid hormones, hepatic proteins, lipids, and quality of life in menopausal women with hypothyroidism: a clinical trial.

The aim of the study was to evaluate the effects of usual doses of oral estradiol with transdermal estradiol and the effects of these estrogens plus micronized progesterone (MP) in menopausal women with primary hypothyroidism. Twenty women were randomized to 12 weeks of treatment with estradiol 1 mg tablets or estradiol 1 mg gel. Then, women with a uterus received a 100 mg capsule of oral MP. Thyroid function, thyroxine-binding globulin (TBG), sex hormone-binding globulin (SHBG), insulin-like growth factor 1 (IGF-1), lipid profiles, and quality of life were measured at baseline and after 12 and 24 weeks. Oral estradiol led to an increase in total T4 levels (5.84 ± 1.11 vs 8.41 ± 1.61 μg/dL; P < 0.001); changes in thyroid-stimulating hormone (TSH) levels were clinically important in 3 of 10 participants who needed to increase their dose of levothyroxine. Significant changes were detected in hepatic proteins with oral estradiol: TBG and SHBG levels increased (15.29 ± 3.87 vs 20.84 ± 5.49 μg/mL, P < 0.001; 61.85 ± 33.6 vs 121.4 ± 49.36 nmol/L, P < 0.001; respectively), whereas IGF-1 levels decreased (152 ± 38.91 vs 96 ± 17.59 ng/mL; P < 0.001). Transdermal estradiol alone did not significantly affect the thyroid function. Transdermal estradiol plus MP led to a decrease in TSH levels (1.79 ± 1.05 vs 1.09 ± 0.52 mIU/L; P = 0.04), while total T4 levels increased (7.54 ± 1.34 vs 9.95 ± 2.24 μg/dL; P = 0.01). Hormonal therapy had a greater impact on depressed mood and vasomotor symptoms. Total T4 and TBG levels increase after oral estradiol in women with hypothyroidism and it may cause clinical changes in TSH levels. Conversely, transdermal estradiol alone or plus MP does not cause major changes in thyroid function in these women.

Switching of Hashimoto Thyroiditis Into Graves’ Disease: A Case Report and Literature Review

Background: Hashimoto thyroiditis (HT) and Graves’ disease (GD) are autoimmune inflammatory thyroid disorders. The evolution from GD into HT is the most common scenario while the conversion from HT into GD seems to be less common. Case Presentation: A 20-year-old female patient referred to the endocrinology clinic with a three-month history of fatigue, lethargy, lack of appetite, constipation, menorrhagia, cold intolerance, and 5 kg weight gain in the last two months. Clinical examination showed dry skin, scalp hair loss, and painless hard goiter whereas thyroid ultrasound revealed generalized homogeneous hypoechoic thyroid hypertrophy. Laboratory tests demonstrated increased serum thyroid-stimulating hormone (TSH) 210 µIU/L (normal: 0.25-4.50), decreased free thyroxine (FT4) 0.37 ng/L (normal: 0.8-1.8) and free triiodothyronine (FT3) 1.94 pg/mL (normal: 1.8-4.6), and finally, increased thyroid peroxidase antibodies (anti-TPO) 462 IU/mL (normal: up to 34). Based on observations, HT was diagnosed and thus daily treatment with levothyroxine 75 mcg was started for the patient. Two months later, she referred with symptoms suggestive of hyperthyroidism with reduced TSH levels, which did not improve after levothyroxine cessation, thus more laboratory tests were conducted and revealed decreased TSH levels, increased T3 and T4, and TSH receptor stimulating antibody (TSAb)levels, and increased radioactive iodine uptake at 24 hours. Therefore, the diagnosis of GD was made. Five weeks after treatment, she was in full remission. Conclusion: Although the switch from HT into GD is rare, it can occur at any time during the disease. Nonetheless, early diagnosis and treatment would improve the quality of care.

Effect of Pesticide Indoxacarb on the Thyroid Gland in Swiss Albino Mice

Background and objectives: Pesticides play an essential role in crop protection, but their overuse caused environmental pollution and harmful effect on different animal body systems, including the endocrine system. The thyroid gland is one of the homeostatic regulators of metabolic activities, which is affected by the elements of the external environment. There are very limited studies on the effect of indoxacarb on the histological architecture and functions of thyroid gland. Therefore, this study was conducted with the aim of examining functionally and histologically of the thyroid gland exposed to indoxacarb. Method: 24 Swiss albino mice male and female were randomly divided into two groups, each group male and female; group I is a control group given orally with 1ml of distilled water and group II orally treated with 120 mg/kg Bw. of indoxacarb daily for 3 weeks. Blood samples were collected from each mouse under anesthetic to determine the thyroid-stimulating hormone (TSH), thyroxine (T4) levels. Thyroid gland histopathology was attained for the evaluation of the indoxacarb effect. Results: The treated mice showed non-significant increase in T4 levels and a significant decrease in TSH levels but there was no significant difference recorded in T4 and TSH levels between sexes. Histologically, the sections of the thyroid gland of the treated group showed empty and irregular follicles, degeneration of the follicular epithelial tissue, and hyperplasia in the lining of some follicles, the capsule with congestion blood vessels. Conclusion: This study concluded that indoxacarb may act as a thyroid gland toxicant.

Environmental Factors Affecting Thyroid-Stimulating Hormone and Thyroid Hormone Levels.

Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels. Among the pollutants analyzed, most studies observed a decrease in thyroid hormone levels after exposure to perchlorate. Future studies should continue to analyze the impact of environmental factors on thyroid function as they could contribute to understanding the complex background of gene–environment interactions underlying the pathology of thyroid diseases.

48-Year-Old Woman With Dyspnea and Chest Pain

48-Year-Old Woman With Dyspnea and Chest Pain

Hypothyroidism and levothyroxine therapy following bariatric surgery: a systematic review, meta-analysis, network meta-analysis, and meta-regression.

Many health benefits of bariatric surgery are known and well-studied, but there is scarce data on the benefits of bariatric surgery on the thyroid function. We aimed to make a meta-analysis regarding the impact of bariatric surgery on thyroid-stimulating hormone (TSH) levels, levothyroxine dose, and the status of subclinical hypothyroidism. Systematic review and meta-analysis. PubMed, EMBASE, and Cochrane Library were searched up to December 2020 for relevant clinical studies. Random-effects model was used to pool results. Network meta-analysis was performed, incorporating direct and indirect comparisons among different types of bariatric surgery. Meta-regression analysis was performed to evaluate the impact of moderator variables on TSH levels and required levothyroxine dose after surgery. We followed the PRISMA guidelines for data selection and extraction. PROSPERO registry number: CRD42018105739. A total of 28 studies involving 1284 patients were included. There was a statistically significant decrease in TSH levels after bariatric surgery (mean difference = -1.66 mU/L, 95%CI [-2.29, -1.03], P < .0001). In meta-regression analysis, we found that the following moderator variables: length of follow-up, mean age, baseline TSH, and preoperative thyroid function, could explain 1%, 43%, 68%, and 88% of the between-study variance, respectively. Furthermore, subclinical hypothyroidism was completely resolved in 87% of patients following bariatric surgery. In addition, there was a statistically significant decrease of levothyroxine dose in frank hypothyroid patients following bariatric surgery (mean difference = -13.20 mcg/d, 95%CI [-19.69, -6.71]). In network meta-analysis, we found that discontinuing or decreasing levothyroxine dose was significant following Roux-en-Y gastric bypass, 1 anastomosis gastric bypass, and sleeve gastrectomy, (OR = 31.02, 95%CI [10.34, 93.08]), (OR = 41.73, 95%CI [2.04, 854.69]), (OR = 104.03, 95%CI [35.79, 302.38]), respectively. Based on our meta-analysis, bariatric surgery is associated with the resolution of subclinical hypothyroidism, a decrease in TSH levels, and a decrease in levothyroxine dose.

Association between decreased thyroid stimulating hormone and hyperuricemia in type 2 diabetic patients with early-stage diabetic kidney disease

BackgroundSerum uric acid (SUA) is associated with the development of diabetic kidney disease (DKD). Thyroid hormones can regulate metabolism and insulin resistance. The relationship between SUA and thyroid function in patients with DKD is still uncertain. In current study, we aimed to investigate the association between thyroid stimulating hormone (TSH) and SUA in type 2 diabetic patients with early-stage DKD.MethodsTwo hundred fifty-four type 2 diabetic patients with early-stage DKD were enrolled in current study and were further classified as high SUA group (SUA level > 420 μmol/L in males or > 360 μmol/L in females, n = 101) and normal SUA group (SUA level ≤ 420 μmol/L in males or ≤ 360 μmol/L in females, n = 153). Eighty-five control subjects were recruited as control group. The clinical characteristics were obtained via face-to-face surveys and medical records.ResultsCompared with normal SUA group and control group, high SUA group exhibited the increased SUA level, and the decreased TSH level (P < 0.017 for all), and no significant difference was detected in SUA and TSH between normal SUA group and control group. TSH was negatively associated with SUA (r = − 0.35, P < 0.001) in type 2 diabetic participants with early-stage DKD. Furthermore, the decreased TSH level was independently correlated with higher SUA level (β = − 25.69, P < 0.001), and retained a significant association with hyperuricemia (odds ratio = 1.73, P = 0.002) after adjusting for confounding factors in type 2 diabetic patients with early-stage DKD.ConclusionsTSH is negatively correlated with SUA, and decreased TSH is an independent risk factor for hyperuricemia in type 2 diabetic patients with early-stage DKD. These results indicate that thyroid hormones, TSH in particular, might participate in regulating uric acid metabolism in patients with early-stage DKD.

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.

Effect of metformin therapy on thyroid-stimulating hormone levels in women with polycystic ovarian syndrome

Introduction: Metformin has been shown to decrease thyroid-stimulating hormone (TSH) levels without effect on total T4 and total T3 levels, especially in patients with underlying thyroid dysfunction. The Aim of the Study: To evaluate the effect of metformin therapy on TSH levels in polycystic ovarian syndrome (PCOS) patients who were euthyroid with or without treatment. Design of the Study Nonrandomized prospective intervention trial. Materials and Methods: The study included all euthyroid PCOS patients of the reproductive age group diagnosed according to the modified Rotterdam criteria and the patients were divided into two groups. The first group was put on lifestyle modification alone (Group-I), whereas the second group was put on lifestyle modification and metformin therapy (Group-II). In both groups of patients, TSH, total T4, and total T3 levels were done at baseline and after 3 months of follow-up. Results: A total of 105 patients with PCOS were nonrandomly assigned to Group I (n = 53) and Group II (n = 52). The baseline parameters (age, body mass index, TSH, and Homeostatic Model Assessment for Insulin Resistance) were similar. Thirty-six patients in Group I and 39 in Group II were followed up for 3 months. The change in TSH levels in both groups was not significant at follow-up (Group I [2.56 ± 0.87 vs. 3.01 ± 1.54; P = 0.102] and Group II [2.90 ± 0.81 vs. 2.76 ± 1.26;P = 0.503]). In a subgroup analysis in patients who had thyroid dysfunction, there was a significant decrease in TSH levels in Group II (3.10 ± 0.54 vs. 2.57 ± 0.50;P = 0.031). Conclusion: Metformin significantly decreased TSH levels in women with PCOS with underlying thyroid dysfunction, while it did not show any effect on women without underlying thyroid dysfunction.