Association Between Worse Metabolic Control and Increased Thyroid Volume and Nodular Disease in Elderly Adults with Metabolic Syndrome

Thyroid cancer and insulin resistance

Thyroid cancer has shown a parallel increase with diabetes in the last few years. This narrative review aims to explain the association between these two entities, focusing on insulin resistance as the mediator and exploring the effects of antidiabetic agents on thyroid cancer incidence and progression.We searched Pubmed for English-written articles on insulin resistance, diabetes, antidiabetic treatments, and thyroid cancer reported from January 2019 to April 2023. Exclusion criteria were preclinical and clinical studies involving a population with thyroid dysfunction, benign nodular goiter, or those that only analyzed thyroid cancer's association with obesity.The results of the narrative literature review revealed 96 articles. Additionally, four studies from a manual search were retrieved. After the exclusion criteria were applied, we included 20 studies. Out of 8 studies on insulin-resistant or Metabolic Syndrome patients, all suggest a positive association with thyroid cancer. At the same time, for diabetes, four out of five publications support a link with thyroid cancer. The seven remaining studies on antidiabetics suggest that metformin might benefit thyroid cancer. In contrast, the evidence for an association between Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and increased thyroid cancer findings is limited.In conclusion, the association between thyroid cancer and diabetes may be explained by insulin resistance, as shown in observational studies. However, the causal role is yet to be defined. Although the wide use of different antidiabetic agents has been related to thyroid cancer prevalence and progression, future research with drugs such as metformin or GLP-1 RA is still needed.

Epidemiological, Pathophysiological, and Clinical Considerations on the Interplay between Thyroid Disorders and Type 2 Diabetes Mellitus

Thyroid disorders (TD) and diabetes mellitus (DM) are the two endocrinopathies with the highest prevalence in the general population that frequently coexist. Thyroid dysfunction is more common in people with type 2 diabetes mellitus (T2DM) compared to normoglycemic individuals. Untreated TD can impair glycemic control, increasing the risk of diabetes complications. Hyperinsulinemia can affect the morphology of the thyroid gland by promoting the proliferation of thyroid tissue and increasing the size of thyroid nodules. Metformin can confer benefits in both endocrinopathies, while other antidiabetics, such as sulfonylureas, can negatively affect thyroid function. Animal and human observational data suggest an increased risk of medullary thyroid carcinoma after treatment with glucagon-like peptide-1 receptor agonists. However, randomized trials have so far been reassuring. Furthermore, some observational studies suggest an association between thyroid cancer and T2DM, especially in women. This narrative review aims to shed light on the epidemiological, pathophysiological, and clinical aspects of the interplay between TD and T2DM. Taking into account the important clinical implications of the coexistence of T2DM and TD, proper screening and management strategies are needed for both endocrinopathies to ensure optimal patient care.

The association between thyroid-stimulating hormone and thyroid nodules, goiter and thyroid antibody positivity

Background

The relationship between normal thyroid-stimulating hormone (TSH) levels and thyroid disease in adults remains controversial. This study aimed to investigate the correlation between serum TSH levels, particularly those falling within the normal range, and thyroid diseases in Chinese adults, including thyroid nodules (TN), goiter (GR), and thyroid antibody positivity.

Materials and methods

This research was a cross-sectional study conducted in an adult population in Tianjin, China. Thyroid volume (Tvol) and TN were assessed using thyroid ultrasonography. Fasting venous blood and spot urine samples were collected to evaluate thyroid function and iodine status.

Results

A total of 2460 subjects participated in the survey. The prevalence of thyroid dysfunction was 9.76%, and abnormal TSH levels were found to potentially increase the risk of GR and thyroid antibody positivity in adults. A total of 2220 subjects with TSH within the normal reference range were included in the further study. In these patients, Tvol decreased as TSH levels increased, in both men and women (P < 0.0001). Low TSH levels (0.27-1.41 IU/mL) were identified as a risk factor for TN (odds ratio [OR], 1.46; 95% CI: 1.14-1.87) and GR (OR 5.90, 95% CI 2.27-15.3). Upon stratification by sex and age, the risk of TN was found to be higher in women and elderly individuals (≥60 years old), while the risk of GR was found to be higher in men and younger individuals (<60 years old). High TSH levels (2.55-4.2 IU/mL) were identified as a risk factor for thyroid antibody positivity (OR, 1.53; 95% CI: 1.11-2.10). Men and younger individuals with high TSH levels exhibited a higher risk of thyroid antibody positivity.

Conclusion

In adults with normal TSH levels, low TSH levels were associated with an increased risk of TN and GR, whereas high TSH levels were associated with thyroid antibody positivity. The research also suggests that adults whose TSH levels at upper or lower limits of the normal range should be reviewed regularly.

Metformin Attenuates Inflammation and Fibrosis in Thyroid-Associated Ophthalmopathy

The pathogenesis of thyroid-associated ophthalmopathy (TAO) is still unclear, and therapeutic drugs have great limitations. As metformin has multiple therapeutic effects in many autoimmune diseases, we explored the effects of metformin on TAO in an in vitro fibroblast model. We used orbital connective tissues and fibroblasts that were obtained from TAO patients and normal controls. The activity of adenosine monophosphate-activated protein kinase (AMPK) and the levels of inflammatory or fibrotic factors were examined by immunofluorescence (IF) and immunohistochemistry (IHC). Quantitative real-time polymerase chain reaction (qPCR), cytokine quantification by enzyme-linked immunosorbent sssay (ELISA), IF, and western blotting (WB) were used to measure the expression of factors related to inflammation, fibrosis, and autophagy. To determine the anti-inflammatory and antifibrotic mechanisms of metformin, we pretreated cells with metformin, 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR, an AMPK activator) or compound C (CC, an AMPK inhibitor) for 24 h and used WB to verify the changes in protein levels in the AMPK/mammalian target of rapamycin (mTOR) pathway. We determined that the low activity of AMPK in the periorbital tissue of TAO patients may be closely related to the occurrence and development of inflammation and fibrosis, and metformin exerts multiple effects by activating AMPK in TAO. Furthermore, we suggest that AMPK may be a potential target of TAO therapy.

Effects of Slow-Acting Metformin Treatment on the Hormonal and Morphological Thyroid Profile in Patients with Insulin Resistance

Metformin appears to reduce TSH levels in untreated hypothyroid patients. In contrast, in euthyroid patients with type 2 diabetes mellitus (T2DM), metformin is initially devoid of effects on TSH. However, it is followed by a significant reduction in TSH level after twelve months of treatment. Additionally, some evidence suggests that metformin may also improve thyroid morphological abnormalities. This study aimed to evaluate the effects of metformin not only on TSH and thyroid hormone values, but also on thyroid volume and nodules. A total of 50 patients (mean age: 36.9 ± 12.8 years) with insulin resistance (homeostatic model assessment (HOMA) index ≥2.5) and with thyroid uninodular disease were recruited for this study. They were prescribed slow-acting metformin at a daily dose of 500 mg for six months. Treatment with metformin in euthyroid patients with uninodular thyroid disease and insulin resistance reduces TSH levels, increases FT4 and FT3 values, and decreases thyroid and nodule volumes. These data suggest that metformin may be an effective drug not only for the treatment of T2DM and metabolic syndrome, but also for thyroid disease.

Selenium and Selenoproteins at the Intersection of Type 2 Diabetes and Thyroid Pathophysiology

Type 2 diabetes (T2D) is considered one of the largest global public-health concerns, affecting approximately more than 400 million individuals worldwide. The pathogenesis of T2D is very complex and, among the modifiable risk factors, selenium (Se) has recently emerged as a determinant of T2D pathogenesis and progression. Selenium is considered an essential element with antioxidant properties, and is incorporated into the selenoproteins involved in the antioxidant response. Furthermore, deiodinases, the enzymes responsible for homeostasis and for controlling the activity of thyroid hormones (THs), contain Se. Given the crucial action of oxidative stress in the onset of insulin resistance (IR) and T2D, and the close connection between THs and glucose metabolism, Se may be involved in these fundamental relationships; it may cover a dual role, both as a protective factor and as a risk factor of T2D, depending on its basal plasma concentration and the individual’s diet intake. In this review we discuss the current evidence (from experimental, observational and randomized clinical studies) on how Se is associated with the occurrence of T2D and its influence on the relationship between thyroid pathophysiology, IR and T2D.

Proteomic profiling of thyroid tissue in patients with obesity and benign diffuse goiter

Goiter is a term to describe the enlargement of the thyroid gland. The pathophysiology and molecular changes behind development of diffuse benign goiter remains unclear. The present study targeted to identify and describe the alterations in the thyroid tissue proteome from patients (obese euthyroid) with benign diffuse goiter (BDG) using proteomics approach. Thyroid tissue samples, from 7 age and sex matched, patients with BDG and 7 controls were obtained at the time of surgery. An untargeted proteomic analysis of the thyroid tissue was performed out utilizing two-dimensional difference (2D-DIGE) in gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for identification of the proteins. Progenesis software was used to identify changes in expression of tissue proteins and found statistically significant differences in abundance in a total of 90 proteins, 46 up and 44 down (1.5-fold change, ANOVA, p ≤ 0.05) in BDG compared to the control group. Bioinformatic analysis using Ingenuity Pathway Analysis (IPA) identified dysregulation of signalling pathways linked to ERK1/2, Glutathione peroxidase and NADPH oxidase associated to organismal injury and abnormalities, endocrine system disorders and cancer. The thyroid tissue proteome in patients with BDG revealed a significant decrease in thyroglobulin along with dysregulation of glycolysis and an increase in prooxidant peroxidase enzymes. Dysregulation of metabolic pathways related to glycolysis, redox proteins, and the proteins associated with maintaining the cytoskeletal structure of the thyrocytes was also identified.

The Detection of Thyroid Nodules in Prediabetes Population and Analysis of Related Factors

Purpose

To explore the detection of thyroid nodules (TN) and related influencing factors in the population of prediabetes (PreDM) in northwest China’s Gansu Province.

Materials and Methods

A multi-stage stratified cluster random sampling method was used to select adult Han residents in Gansu Province for investigation, and recorded the clinical data of the subjects. The χ² test was used to analyze the difference in TN detection rate of the PreDM population. Logistic regression analyzed the risk factors of TN in the PreDM population.

Results

This study included 2659 people with normal glucose tolerance (NGT) and PreDM, of which 440 people were detected with TN. Among the PreDM population, the TN detection rate was higher than in the NGT population (24.48% vs 15.00%; P<0.05). The detection rate of TN in the impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and IFG+IGT group was also significantly higher than that in the NGT population (X²=4.117, X²=13.187, X²=13.016, all P<0.05), and of which, the IFG+IGT group was the highest (32.20%). The general trend of TN in the IFG, IGT and PreDM population all increased with age. General data showed that BMI, waist-to-height ratio, waist circumference, TG, TC, LDL-C, FPG, 2h PG, HbA1c and TSH indicators in the TN group were higher than those in the Non-TN group (P<0.05). The logistic regression suggested that the risk factors for TN in the PreDM population were female, age increase, high SP, high TSH, high FPG, high LDL-C, hypertension and family history of diabetes (all P<0.05).

Conclusion

The detection rate of TN in the PreDM population is high, especially in the IFG+IGT population. Middle-aged and elderly people with hypertension and abnormal glucose and lipid metabolism should be treated reasonably and regularly, and their TN should be screened and followed up.

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.

Association between thyroid dysfunction and type 2 diabetes: a meta-analysis of prospective observational studies

BACKGROUND

Diabetes mellitus and thyroid disease are two areas of broad interest in the field of endocrinology and metabolism. Variation of thyroid hormone concentration, even within the normal range, may portend the onset of type 2 diabetes mellitus (T2DM), especially among those with prediabetes. However, current evidence is mixed.

METHODS

Prospective studies which assessed diabetes incidence were identified using a database search of MEDLINE and Embase through May 1, 2021. The Sidik-Jonkman random-effects model and cubic spline model were used to evaluate the associations and dose-response relationships between thyroid function/hormone levels and risk of T2DM and cardiovascular disease (CVD) risk among T2DM patients.

RESULTS

A total of 12 prospective studies were included. We found that high baseline TSH levels were related to a 17% higher risk of T2DM (RR 1.17, 95% CI 1.01, 1.36; I²=78%, P<0.01), compared with normal TSH levels. Low FT3 (RR 1.40, 95% CI 1.09, 1.80; I²=59%, P=0.03) and low FT4 (RR 1.33, 95% CI 1.04, 1.71; I²=62%, P=0.02) levels were significantly associated with risk of T2DM. The cubic spline model indicated a J-shaped relationship with TSH, but inverted-J-shaped relationships with FT3 and FT4. CVD events and all-cause deaths were prospectively evaluated in four studies, but were not associated with abnormal thyroid function.

CONCLUSIONS

Our meta-analysis determined that abnormal thyroid hormone level is associated with an increased risk of T2DM, showing a J-shaped relationship with TSH and inverted-J-shaped relationships with FT3 and FT4.

TRIAL REGISTRATION

Registered number in PROSPERO: CRD42021225695 .

Metabolic syndrome and its components are associated with thyroid volume in adolescents

OBJECTIVE

To explore the association between metabolic syndrome (MetS) and its component and thyroid volume in Chinese adolescents, and to compare the detection rate of MetS under the three different diagnostic criteria.

METHODS

A total of 1097 school students (610 males and 487 females, ages 12-15 years) were enrolled. All the participants underwent physical examination, biochemical test, and thyroid gland ultrasonography. The thyroid volume of normal, overweight and obese group was compared. We also analyzed the association between the number of MetS components and thyroid volume. Linear and multiple linear regression were applied to explore the association between metabolic parameters and thyroid volume.

RESULTS

The thyroid volume of the males in overweight (t = 3.784, P < 0.001) and obese group (t = 5.068, P < 0.001) was significantly larger than that in normal group; the thyroid volume of the females in overweight group (t = 4.627,P < 0.001) was significantly larger than that of normal group. As the number of MetS components increased, the thyroid volume also increased significantly (F = 10.64, P < 0.01). Height, weight, body mass index (BMI), waist circumference, hip circumference, systolic blood pressure, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), uric acid and triglyceride were all positively associated with thyroid volume in the adolescents (P all < 0.001). Meanwhile, there was a negative association between high-density lipoprotein cholesterol (HDL-C) and thyroid volume (P < 0.001). According to multiple linear regression, waist circumference (β = 0.029, 95 %CI: 0.015 ~ 0.042; P < 0.01) and waist height ratio (β = 3.317, 95 %CI: 1.661 ~ 4.973; P < 0.01) were predict factors of thyroid volume. No statistical difference was found in the detection rates of metabolic syndrome under the three diagnostic criteria.

CONCLUSIONS

Overweight, obesity and metabolic syndrome was associated with adolescent thyroid volume. Central obesity may be an independent risk factor for thyroid enlargement in adolescents.

Relationship between urinary metabolites of polycyclic aromatic hydrocarbons and risk of papillary thyroid carcinoma and nodular goiter: A case-control study in non-occupational populations

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to the development of certain diseases. However, the relationship between PAH exposure and thyroid disorders remains unknown. We measured 10 of the most common hydroxylated PAHs (OH-PAHs) in the urine of thyroid nodular goiter (NG) patients, papillary thyroid carcinoma (PTC) patients, and healthy controls by gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS). We found that the concentrations of 2-hydroxyfluorene (2-OH-FLU), 2-hydroxydibenzofuran (2-OH-DBF), and 1-hydroxyphenanthrene (1-OH-PHE) in the NG group, and of 2-hydroxynaphthalene (2-OH-NAP), 2-OH-DBF, and 1-OH-PHE in the PTC group were significantly higher than those in controls. In addition, participants in the high tertiles of 2-OH-FLU and 1-OH-PHE had higher risk of NG. Besides these two OH-PAHs, elevated risk of NG was observed in women in the high tertiles of 1-hydroxynaphthalene (1-OH-NAP), 2-OH-NAP, 2-OH-DBF, and 3-hydroxyfluorene (3-OH-FLU). Furthermore, participants in the high tertiles of seven OH-PAHs, namely, 1-OH-NAP, 2-OH-NAP, 2-OH-DBF, 2-OH-FLU, 3-OH-FLU, 3/9-hydroxyphenanthrene (3/9-OH-PHE), and 1-OH-PHE, had elevated risk of PTC, and females in these high tertiles had an even higher risk of PTC. Our findings suggest that PAH exposure may increase the risk of NG/PTC, and there may be a gender-specific effect of PAH exposure on the development of NG/PTC.

The Relationship and Gender Disparity Between Thyroid Nodules and Metabolic Syndrome Components Based on a Recent Nationwide Cross-Sectional Study and Meta-Analysis

BACKGROUND

Metabolic syndrome (MetS) has a potential connection with thyroid disease, but its relationship with thyroid nodules (TNs) is still controversial. This study aims to clarify the relationship between MetS and TNs, and this relationship in the subgroup of gender.

METHODS

The recent nationwide cross-sectional study called Thyroid Disorders, Iodine Status, and Diabetes Epidemiological survey provided the newest data on the relationship between MetS and TNs from China and included 56,729 subjects. We also researched related literature in PubMed, EMBASE, Cochrane Library, and MEDLINE until Oct 30, 2020, in order to perform a meta-analysis. The relevant articles were examined, and the eligible studies were included to assess the association between MetS and TNs.

RESULTS

The meta-analysis included 15 studies (involving 468,845 subjects). Of these, 14 studies were from the databases, and one study was this cross-sectional data. The meta-analysis showed that TNs were associated with a higher prevalence of MetS (OR=1.87, 95% CI: 1.44-2.45) and the components of MetS, including central obesity (OR=1.41, 95% CI: 1.15-1.72), hypertriglyceridemia (OR=1.13, 95% CI: 1.10-1.15), low high-density lipoprotein cholesterolemia (OR=1.11, 95% CI: 1.02-1.20), abnormal blood pressure (OR=1.68, 95% CI: 1.62-1.75), and hyperglycemia (OR=1.59, 95% CI: 1.46-1.74). Central obesity displayed gender differences, being a risk factor in males (OR=1.38, 95% CI: 1.02-1.86) but not in females (OR=1.47, 95% CI: 0.97-2.23).

CONCLUSION

TNs were indeed associated with a higher prevalence of MetS. In addition, its component diseases, such as central obesity, hypertriglyceridemia, abnormal blood pressure, and hyperglycemia, were also associated with TNs. Females with MetS or its components had a higher risk of suffering from TNs than males.

Association of Changes in Metabolic Syndrome Status With the Incidence of Thyroid Nodules: A Prospective Study in Chinese Adults

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline (n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years).

Review of Factors Contributing to Nodular Goiter and Thyroid Carcinoma

There is an increased incidence of thyroid nodules and cancer. In this article, the reasons for this increase are evaluated and discussed. The factors causing increases in the incidence of nodules are the same as those causing increases in thyroid cancer. There are publications from all over the world regarding the rising incidence of thyroid cancer; it is especially associated with papillary cancer. The literature was reviewed and evaluated with regard to this significant phenomenon. Thyroid-stimulating hormone (TSH) is the main mitotic factor. Any agent that elevates TSH will stimulate nodule formation. Therefore, the incidence of thyroid nodules is high in endemic goiter regions due to iodine deficiency. This paper has described many of the factors causing this higher incidence. Of note, metabolic syndrome and insulin resistance are important factors associated with the increased incidence of nodular goiter and papillary thyroid cancer today. However, these data must be confirmed by other studies in the future.

Association between metabolic syndrome and euthyroid nodular goiter: a case-control study

Background:

Metabolic syndrome is a cluster of metabolic abnormalities and abdominal obesity; its pathophysiologic basis, insulin resistance, has been shown to act as agent in thyroid cell proliferation. Few studies analyze the relationship between metabolic syndrome and thyroid nodular disease, with a substantial knowledge gap.

Objective:

Determine the association between metabolic syndrome and nodular thyroid disease in a region with adequate iodine intake.

Methods:

Case-control study. A total of 182 patients referred to radiology to undergo thyroid ultrasonography due to suspicion of thyroid disease. Cases had at least one thyroid nodule greater than 3 mm (n= 91). Controls did not have evidence of thyroid nodules (n= 91).

Results:

Bivariate analysis showed a significant association between metabolic syndrome and the presence of thyroid nodule (OR 2.56, 95% CI: 1.41-4.66, p <0.05). Low levels of HDL (OR 2.81, 95% CI: 1.54-5.12, p <0.05) and impaired fasting glucose (OR 2.05, 95%CI 1.10 to 3.78, p <0.05) were significantly associated with the presence of thyroid nodule, independent of the presence of metabolic syndrome. Multivariate analysis maintained the association between metabolic syndrome and thyroid nodule with an OR of 2.96 (95%CI 1.47 to 5.95, p <0.05); similarly, the associations of low levels of HDL (OR 2.77, 95%CI 1.44 to 5.3, p <0.05) and impaired fasting glucose (OR 2.23, 95%CI 1.14 to 4.34, p<0.05) with thyroid nodule remained significant.

Conclusion:

The thyroid nodular disease is associated with increased risk of metabolic syndrome, specifically decreased HDL and impaired fasting glucose levels were the factors that increased association was found.

Relationship between metabolic syndrome and thyroid nodules and thyroid volume in an adult population

PURPOSE

The effects of metabolic syndrome (MetS) on thyroid nodules (TN) and thyroid volume (TV), especially the related gender and age disparities, are controversial. In this study, we aimed to assess the relationships between MetS and TN and TV in an adult population.

METHODS

This cross-sectional study was performed in an adult population in Tianjin. A total of 2606 subjects were enrolled. TV and TN were measured by thyroid ultrasonography. Blood samples were collected to measure biochemical and metabolic parameters.

RESULTS

The prevalence of TN was significantly higher in the MetS (+) group than in the MetS (-) group (P < 0.0001). MetS was independently associated with increased TN risk (OR: 1.24, 95% CI: 1.01-1.51). When stratified by gender, MetS was associated with higher prevalence of TN in males (OR: 1.38, 95% CI: 1.05-1.81) compared with females (OR: 1.02, 95% CI: 0.75-1.39). However, the interaction effect of gender and MetS on TN was not statistically significant (P for interaction = 0.94). MetS was associated with the greater risks of TN in both the <60-year-old group (OR: 1.32, 95% CI: 1.05-1.68) and the ≥60-year-old group (OR: 1.84, 95% CI: 1.24-2.73), while the OR value was significantly higher in the elderly group (P for interaction = 0.03). Additionally, TV was significantly higher in subjects with TN (β = 1.94, P < 0.0001) and MetS (β = 0.94, P = 0.0037).

CONCLUSIONS

This study suggested positive relationships between MetS and an increased risk of TN and enlarged TV. Elderly people (≥60 years old) with MetS were associated with a higher risk of TN than younger people (<60 years old). The effect of MetS on TN was not significantly affected by gender.

Thyroid Nodules in Type 2 Diabetes Mellitus

The present analysis aims to investigate the prevalence of thyroid nodules in type 2 diabetes mellitus (T2DM) population. We searched PubMed, EMBASE, and Web of Science from inception to the March 1, 2018. The studies were selected to estimate the prevalence of thyroid nodules in T2DM subjects and to compare the prevalence of thyroid nodules in different glucose tolerance status. The random effects model was used, and the outcome was presented as a pooled prevalence proportion with 95% confidence interval (95% CI) or a summary odds ratio (OR) with 95% CI. In the end, 9 studies met the inclusion criteria and were included in the analysis. The pooled prevalence of thyroid nodules was 60% (95% CI: 0.52, 0.68) for T2DM 2 diabetes patients, 50% (95% CI: 0.48, 0.51) for pre-diabetes, and 43% (95% CI: 0.34, 0.52) for normal glucose tolerance population. Compared with patients without diabetes, diabetes subjects are more likely to develop thyroid nodules, adjusted OR for thyroid nodule was 1.78 (95% CI: 1.25, 2.55). Insulin resistance might be involved in thyroid nodule development.

Risk Factors of Thyroid Dysfunction in Patients With Type 2 Diabetes Mellitus

Background: Thyroid dysfunction has been widely reported among persons with diabetes (DM) in other parts of the World. In Nigeria, few studies have been reported. This study focused on risk factors for thyroid dysfunction in type 2 diabetes mellitus (T2DM) patients and will therefore add to the Nigerian literature, more so, as it is the first in South-East Nigeria. Objective: To determine the risk factors of thyroid dysfunction in patients with Type 2 DM. Methodology: Three hundred and fifty-four T2DM patients and 118 non-diabetic persons (controls) were recruited for the study. A pretested questionnaire was filled for each subject after due explanations. The subjects were subsequently examined and the findings, including anthropometric values and clinical parameters were documented. Their blood samples were tested for HbA1c, fT3, fT4, and TSH. Information retrieved from patients medical records included: age at diagnosis of DM, duration of DM, complications of DM. The Student's t-test, chi square test and regression analysis were used in the analysis of the data obtained. P < 0.05 was taken to be statistically significant. Results: About 56.5% of the T2DM patients who participated in this study were females and 62.7% of the controls were females. The T2DM patients had significantly higher BMI than controls (27.6 ± 5.0 kg/m2 vs. 26.2 ± 3.8 kg/m2, p = 0.002). Mean HbA1c was significantly higher in T2DM patients than in the controls (7.8 ± 2.0% vs. 5.8 ± 1.2%, p = 0.001). Female gender (OR = 3.8, p = 0.002), central obesity (OR = 2.5, 95%CI = 1.5-5.2, p = 0.001), DM nephropathy (OR = 4.8, p = 0.001), HbA1c ≥7% (OR = 4.3, p = 0.025) and duration of DM >5years (OR = 3.3, p = 0.012) were significantly associated with thyroid dysfunction in T2DM patients in this study. Conclusion: Female gender, central obesity, DM nephropathy, above normal HbA1c, and duration of DM were risk factors of thyroid dysfunction in type 2 DM patients in this study.

The influence of the lack of insulin receptor substrate 2 (IRS2) on the thyroid gland

Involvement of IRS2 in the proliferative effects of IGF-I of follicular thyroid cells has been described, but there are no evidences for in vivo participation of IRS2. This study aimed to analyse the in vivo relevance of IRS2 in the proliferation and apoptosis of thyroid cells by immunocytochemical studies for PCNA, Ki67, and active-caspase-3 in thyroid cells of IRS2 knockout (IRS2-KO) mice, jointly to TUNEL assay. Thyroid hormones were lower in IRS2-KO mice than in their wild-type (WT) counterparts. Increases in the area, perimeter and diameter of thyroid follicles of IRS2-KO mice were observed, which also showed increased proliferation rate of follicular cells and decreased percentage of apoptotic cells that was more evident in the central than in the marginal region of the gland. Sex-related differences were also found, since the follicular epithelium height was higher in male than in female mice. The percentage of proliferating cells showed significant changes in male but not in female mice, and apoptotic cells were more abundant in female than in male IRS2-KO animals, without significant differences between WT-animals. Therefore, our results suggest that IRS2 could be involved in the maintenance of thyroid cells population and in the normal physiology of the thyroid gland.

Association Between Thyroid Nodules and Volume and Metabolic Syndrome in an Iodine-Adequate Area: A Large Community-Based Population Study

Background: Given its high incidence, thyroid nodule (TN) warrants public attention. Thyroid volume (TV) has also been associated with multiple factors, such as iodine deficiency and supply and body mass index. It is well known that metabolic syndrome (MetS) comprises many metabolic disturbances, with insulin resistance being its major component. Materials and Methods: The aim of this study was to investigate the relationship between TN and TV and MetS and its components in an iodine-adequate area in Asia. All participants were asked to complete a questionnaire. After excluding 938 individuals based on the exclusion criteria, we reviewed data from 927 of 1865 participants. Adopting MetS diagnostic criteria, we found 437 subjects to be MetS positive [MetS(+)] and 490 subjects to be MetS negative [MetS(-)], respectively. Multivariate linear regression was used to assess the relationship between TNs and MetS. Moreover, univariate binary logistic regression analyses were used to calculate odds ratios (ORs), and 95% confidence intervals (CIs) were used to estimate the associations between different variables and TNs. Results: A total of 232 females and 205 males were MetS(+), as diagnosed using the International Diabetes Federation criteria. However, there were 330 females and 160 males in the group of MetS(-) individuals. The prevalence of TNs was 38.29% in the MetS(+) group and 17.79% in the MetS(-) group. After adjusting for systolic blood pressure, diastolic blood pressure, and gender, only high-density lipoprotein, waist circumference (WC), and age were related to TNs (OR = 0.45, 95% CI 0.27-0.75, P = 0.0023; OR = 1.04, 95% CI 1.02-1.06, P = 0.0036). The TV of all participants was 13.98 (11.24, 17.01) mL; 13.26 (10.62, 16.17) mL for females and 14.96 (11.83, 18.01) mL for males. It was found that only WC was related to TV, after controlling for sex and age (P = 0.02). Conclusions: The morbidity among TN patients in the MetS(+) group was higher than that among the MetS(-) group. High-density lipoprotein cholesterol emerged as a protective factor, and WC was a risk factor for TN. Moreover, TV was related to MetS, and WC was an independent risk factor for TV.

The Impact of Metabolic Syndrome on Increased Risk of Thyroid Nodules and Size

Aim:

The present research aimed to determine the relation between metabolic syndrome (MetS) and thyroid volume and nodule prevalence among Turkish population patients.

Methods:

This retrospective cohort study was carried on 850 patients between the ages of 20 and 65 who visited the diabetic, endocrinology, and general surgery outpatient clinics in the Mega Medipol and Medipol Hospital between January 2014 and December 2017. This study included sociodemographic information, body mass index (BMI), diabetes mellitus (DM), systolic (SBP) and diastolic (DBP) blood pressures, and clinical biochemistry results such as serum triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL) cholesterol, hemoglobin A1c (HbA1c), fasting blood glucose levels, thyroid-stimulating hormone (TSH), T3, T4, and other MetS parameters. Thyroid fine needle aspiration biopsy was suggested to patients whose thyroid nodules were greater than 1.00 cm. The definition and diagnostic of MetS used as proposed by the National Cholesterol Education Program—Third Adult Treatment Panel.

Results:

There were statistically significant differences between patients with thyroid nodules and those without regarding age, gender, BMI, physical activity, cigarette smoking, shisha smoking, family history of diabetes, hypertension, and thyroid. Meanwhile, statistically significant differences were found between with and without MetS for calcium (P = .028), magnesium (P < .001), potassium (P < .001), fasting blood glucose (P = .047), HbA1c (P < .001), HDL (P < .001), LDL (P < .001), albumin (P = .008), bilirubin (P = .002), triglyceride (P = .011), SBP (P = .001) and DBP (P = .011), TSH (P = .005), T3 (P < .001), and T4 (P < .001). Furthermore, there were statistically significant differences between participants with and without thyroid nodules for calcium (P < .001), magnesium (P < .001), potassium (P < .001), fasting blood glucose (P = .010), HbA1c (P = .019), HDL (P < .001), LDL (P = .012), albumin (P = .002), bilirubin (P < .001), triglyceride (P < .001), SBP (P < .001) and DBP (P = .004), TSH (P = .015), T3 (P < .001), and T4 (P < .001). Multivariate stepwise logistic regression analysis used for independent predictors for the presence of thyroid nodules which TSH (P < .001), family history of thyroid and DM (P < .001), age in years (P = .025), DBP and SBP (P < .001), BMI (P = .014), HDL-C (P = .034), and waist circumference (in cm; P = .044) were considered at higher risk as a predictors of thyroid with patients with MetS.

Conclusion:

The results of the current study confirm a strong positive association between MetS and thyroid nodules risk among patients with MetS. This study suggest that the patients with MetS can be considered as a marker to have moderately increased risk of future thyroid nodules and cancer. Meanwhile, MetS, obesity, and hyperglycemia could be a qualifiable and modifiable risk factor for thyroid nodules. The regularly glycemic control may be the most important treatment for the reduction of incidence or the prevention of thyroid.

The Association of Thyroid Nodules with Metabolic Status: A Cross-Sectional SPECT-China Study

PURPOSE

The aim of this study was to investigate the association of thyroid nodules (TNs) and their ultrasound (US) characteristics related to malignancy with metabolic status.

METHODS

The data were obtained from a cross-sectional study (SPECT-China, 2014-2015). The study included 9898 participants older than 18 years. Participants underwent several checkups, which included the measurement of anthropometric parameters, blood pressure, TSH levels, glucose, and lipid profiles. TN and nonalcoholic fatty liver disease (NAFLD) were diagnosed by US. TN US characteristics, including microcalcification and a taller-than-wide shape, were recorded.

RESULTS

Participants with TN [TN(+)] had a higher prevalence of metabolic syndrome (Met-S), obesity, central obesity, hyperlipidaemia, diabetes, hypertension, and NAFLD, especially women (all P ≤ 0.001). After full adjustment, logistic regression analysis indicated that metabolic syndrome, obesity, central obesity, and hyperlipidaemia were all independent risk factors for the increased prevalence of TN in both genders (P < 0.05). In terms of TN US imaging characteristics associated with malignancy, being female with obesity, central obesity, and NAFLD had 1.91-fold, 2.09-fold, and 1.75-fold increased risks of developing a taller-than-wide nodule (P = 0.014, 0.004, and 0.027, resp.).

CONCLUSIONS

The status of metabolic disorders might be associated with higher risks of TN in both genders. In women, obesity, central obesity, and NAFLD might contribute to the development of a taller-than-wide nodule. The potential role of metabolic status in the pathogenesis of the thyroid nodule and thyroid cancer remains to be elucidated.

Gender Disparity in the Relationship between Prevalence of Thyroid Nodules and Metabolic Syndrome Components: The SHDC-CDPC Community-Based Study

The study is aimed to investigate the pathogenesis underlying the increased prevalence of thyroid nodule (TN) in different levels of metabolic syndrome (MetS) components and analyze the relationships between TN and MetS components. A total of 6,798 subjects, including 2201 patients with TN, were enrolled in this study. Anthropometric, biochemical, thyroid ultrasonographic, and other metabolic parameters were all measured. There was obviously sexual difference in the prevalence of TN (males 26.0%, females 38.5%, resp.). The prevalence of TN in hyperuricemia (45.7% versus 37.4%, P = 0.001), NAFLD (41.2% versus 36.4%, P < 0.05), and MetS (41.4% versus 35.4%, P < 0.001) groups was significantly increased only in females. Insulin resistance [OR = 1.31 (1.15, 1.49)], MetS [OR = 1.18 (1.03, 1.35)], and diabetes [OR = 1.25 (1.06, 1.48)] were all independent risk factors for TN in total subjects, whereas, after stratified analysis of gender, MetS [OR = 1.29, (1.09, 1.53)] and diabetes [OR = 1.47, (1.17, 1.84)] are still strongly and independently associated with the higher risks of TN in female subjects, but not in males. Our results suggest that the components of MetS might associate with the higher risks of TN in women than in men, but further cohort study of this gender disparity in the association between TN and MetS is required.

Metformin and thyroid disease

An intriguing area of research in thyroidology is the recently discovered association of insulin resistance with thyroid functional and morphological abnormalities. Individuals with hyperinsulinemia have larger thyroid gland and a higher prevalence of thyroid nodules and cancer. Accordingly, patients treated with metformin have a smaller thyroid volume and a lower risk of incident goiter, thyroid nodule and cancer. Multiple studies in vitro and in vivo have demonstrated that metformin can inhibit the growth of thyroid cells and different types of thyroid cancer cells by affecting the insulin/IGF1 and mTOR pathways. Besides, metformin treatment was associated with a decrease in the levels of serum thyroid-stimulating hormone (TSH) in diabetic patients possibly by enhancing the effects of thyroid hormones in the pituitary and activating the adenosine monophosphate-activated protein kinase (AMPK). Based on this evidence, metformin appears to be a promising therapeutic tool in patients with thyroid disease. More clinical studies are necessary to evaluate the clinical significance of metformin for the treatment of thyroid diseases.

Correlation between Insulin Resistance and Thyroid Nodule in Type 2 Diabetes Mellitus

OBJECTIVE

The present study explored the association between insulin resistance (IR) and the clinical characteristics of thyroid nodules in patients with type 2 diabetes mellitus (T2DM).

METHODS

All the patients were newly diagnosed with T2DM. 201 patients with thyroid nodule disease and 308 patients without the nodular thyroid disease. The participants were evaluated by relevant examination. Correlation analyses and regression analyses were performed to examine the relationships between the two groups.

RESULTS

HOMA-IR values, serum FT4 (free thyroxine) levels, and age were higher in the thyroid nodule group than in the control group. The proportion of women in the thyroid nodule group is greater than the proportion of women in the control group. Logistic regression analysis showed that age, sex, FT4, and HOMA-IR were positive factors for thyroid nodule. The volume and size of the thyroid nodule were positively correlated with HOMA-IR, irrespective of gender. The thyroid nodule volume and size and the TSH (thyroid stimulating hormone) were greater in females than in males, whereas FT3 (free triiodothyronine) was lower in females.

CONCLUSION

IR might be a risk factor for thyroid nodule. Whether alleviating the IR might slow the growth, or diminish the volume and size of the thyroid nodules, is yet to be elucidated.

Factors Associated with the Prevalence of Thyroid Nodules and Goiter in Middle-Aged Euthyroid Subjects

The aim of the present study was to determine associations of thyroid hormone levels and different metabolic parameters and anthropometric measurements with volume of nodular and nonnodular thyroid as well as with prevalence of goiter and thyroid nodules in middle-aged euthyroid subjects. Methods. The study consisted of 317 euthyroid subjects aged 48-49 from the Kaunas Cardiovascular Risk Cohort study. Thyroid-stimulating hormone (TSH), free thyroxine (FT4), and antithyroid peroxidase antibody (ATPO) levels, as well as anthropometric and metabolic parameters and smoking information, were evaluated. Results. In subjects with and without thyroid nodules, thyroid volume correlated with components of metabolic syndrome, body mass index (BMI), smoking, and TSH levels. In the nonnodular thyroid group, thyroid volume was also positively related to serum insulin and HOMA-IR, whereas a negative correlation between thyroid volume and leptin was identified in the nodular thyroid group. The goiter was identified in 12.3% of subjects. Female gender, thyroid nodules, smoking, BMI, and levels of TSH were independent predictors for goiter. Thyroid nodules were found in 31.2% of participants. Female gender, higher TSH levels, and thyroid volume were independent risk factors for thyroid nodules. Conclusions. Female gender, thyroid nodules, smoking, BMI, and TSH levels were identified as potential predictors of goiter. Female gender, TSH levels, and thyroid volume predicted the presence of thyroid nodules.

Insulin Resistance: Any Role in the Changing Epidemiology of Thyroid Cancer?

In the past few decades, the incidence of thyroid cancer (TC), namely of its papillary hystotype (PTC), has shown a steady increase worldwide, which has been attributed at least in part to the increasing diagnosis of early stage tumors. However, some evidence suggests that environmental and lifestyle factors can also play a role. Among the potential risk factors involved in the changing epidemiology of TC, particular attention has been drawn to insulin-resistance and related metabolic disorders, such as obesity, type 2 diabetes, and metabolic syndrome, which have been also rapidly increasing worldwide due to widespread dietary and lifestyle changes. In accordance with this possibility, various epidemiological studies have indeed gathered substantial evidence that insulin resistance-related metabolic disorders might be associated with an increased TC risk either through hyperinsulinemia or by affecting other TC risk factors including iodine deficiency, elevated thyroid stimulating hormone, estrogen-dependent signaling, chronic autoimmune thyroiditis, and others. This review summarizes the current literature evaluating the relationship between metabolic disorders characterized by insulin resistance and the risk for TC as well as the possible underlying mechanisms. The potential implications of such association in TC prevention and therapy are discussed.