The Relationship between Type 2 Diabetes Mellitus and Related Thyroid Diseases

Relationship Between Serum Thyrotropin Levels and Metabolic Diseases in Older Adults

CONTEXT

Subclinical hypothyroidism is associated with metabolic diseases; however, it remains controversial in older individuals.

OBJECTIVE

This work aimed to investigate the relationship between thyrotropin (TSH) levels and metabolic diseases.

METHODS

In this cross-sectional study, sampling was conducted from nationally representative general communities from 31 provinces in mainland China. A total of6791 older (aged ≥65 years) and 55 303 young participants (aged 18-64 years) were selected after excluding individuals with overt hyperthyroidism or overt hypothyroidism. According to the kit, TSH reference range (0.27-4.2 mU/L) and the age-specific TSH range previously formulated (an upper limit of 8.86 mU/L for older adults and 6.57 mU/L for young adults), the older adults and young adults were separately divided into 4 groups based on their TSH levels. Main outcome measures included anthropometric assessments, serum concentrations of thyroid functions, and various metabolic parameters.

RESULTS

In contrast to young adults, there was no significant increase in the prevalence of any metabolic disorders assessed in the slightly elevated TSH group (TSH 4.21-8.86 mU/L) compared to the euthyroid group (TSH 0.27-4.2 mU/L) among older adults. After adjusting for interference factors, a TSH level higher than 8.86 mU/L was found to be an independent risk factor for low high-density lipoprotein cholesterol (OR, 1.84; 95% CI, 1.14-2.98) and dyslipidemia (OR, 1.49; 95% CI, 1.09-2.04) when compared to the euthyroid group in older adults.

CONCLUSION

Slightly elevated TSH levels are not associated with an increased risk of metabolic diseases in older adults. Therefore, we recommend raising the upper limit of the TSH range for individuals aged 65 years and older.

The complex landscape of intracellular signalling in protein modification under hyperglycaemic stress leading to metabolic disorders

Hyperglycaemia is a life-threatening risk factor that occurs in both chronic and acute phases and has been linked to causing injury to many organs. Protein modification was triggered by hyperglycaemic stress, which resulted in pathogenic alterations such as impaired cellular function and tissue damage. Dysregulation in cellular function increases the condition associated with metabolic disorders, including cardiovascular diseases, nephropathy, retinopathy, and neuropathy. Hyperglycaemic stress also increases the proliferation of cancer cells. The major areas of experimental biomedical research have focused on the underlying mechanisms involved in the cellular signalling systems involved in diabetes-associated chronic hyperglycaemia. Reactive oxygen species and oxidative stress generated by hyperglycaemia modify many intracellular signalling pathways that result in insulin resistance and β-cell function degradation. The dysregulation of post translational modification in β cells is clinically associated with the development of diabetes mellitus and its associated diseases. This review will discuss the effect of hyperglycaemic stress on protein modification and the cellular signalling involved in it. The focus will be on the significant molecular changes associated with severe metabolic disorders.

Prevalence of thyroid dysfunction and associated factors among adult type 2 diabetes mellitus patients, 2000-2022: a systematic review and meta-analysis

BACKGROUND

Thyroid dysfunction (TD) and type 2 diabetes mellitus (T2DM) frequently co-occur and have overlapping pathologies, and their risk increases with age. Thyroid dysfunction along with T2DM will worsen macro- and microvascular complications, morbidity, and mortality.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guideline was followed. The databases used were Embase, ScienceDirect, PubMed, and Google Scholar. The Joana Briggs Institute (JBI) scale was used to assess the quality of the included studies. The data was extracted by Microsoft Excel and analyzed through STATA version 14 software. The overall pooled prevalence of TD and its main components were estimated using the random-effects model. The consistency of studies was assessed by I2 test statistics. Pooled meta-logistic regression was used to present the pooled prevalence with a 95% confidence interval (CI). Besides, subgroup and sensitivity analyses were employed.

RESULT

Thirty-eight studies were included. The pooled prevalence of TD was 20.24% (95% CI: 17.85, 22.64). The pooled prevalence of subclinical hypothyroidism, hypothyroidism, subclinical hyperthyroidism, and hyperthyroidism was found to be 11.87% (95% CI: 6.90, 16.84), 7.75% (95% CI: 5.71, 9.79), 2.49% (95% CI: 0.73, 4.25), and 2.51% (95% CI: 1.89, 3.13), respectively. Subgroup analysis based on continent revealed a higher prevalence of TD in Asia and Africa. Factors like being female, HbA1c ≥ 7%, DM duration > 5 years, family history of TD, central obesity, smoking, the presence of retinopathy, and neuropathy were found associated with TD.

CONCLUSION

The current systematic review and meta-analysis showed that the TD's pooled prevalence was relatively higher than the general population. Therefore, regular screening of TD should be done for T2DM patients.

Association of maternal thyroid disease with obesity in child

OBJECTIVES

During pregnancy, many women develop thyroid disorders, which can result in fetal and neonatal development defects. We investigated whether maternal thyroid dysfunction would affect their children's growth and obesity.

STUDY DESIGN

We conducted a nationwide population-based cohort study using a combination of data from several Korean nationwide registries to investigate the association between maternal thyroid dysfunction, offspring growth, and obesity. Childhood growth was repeatedly measured at three periods of age from 42 to 80 months, using body mass index (BMI).

RESULTS

A total of 1,123,499 women were enrolled in this study; 78,902 (7.0 %) had pre-pregnancy thyroid disease. Significant association was found between maternal hyperthyroidism and obesity in all children aged 42-66 months (42-54 months, adjusted odds ratio (aOR) 0.93, 95 % confidence interval (CI) 0.89-0.98; 54-66 months, aOR 0.93, 95 % CI 0.87-0.99), but not at later ages. In the analysis by sex, maternal hyperthyroidism was associated with childhood obesity in boys, whereas it was not associated with those in girls of any age. No association was observed between maternal hypothyroidism and child BMI or obesity.

CONCLUSIONS

The association between maternal thyroid function and obesity in offspring is attenuated from early to late childhood, suggesting that many other factors may be involved in developing childhood obesity.

Thyroid Eye Disease and Its Association With Diabetes Mellitus: A Major Review

PURPOSE

Thyroid eye disease (TED) associated with diabetes mellitus (DM) presents unique challenges. DM is a risk factor for TED. Standard management of TED with glucocorticoids (GC), orbital radiation, or teprotumumab can cause adverse events in poor glycemic control. The authors reviewed the literature on the relationship between TED and DM and the management of co-existing diseases.

METHODS

The authors searched PubMed with keywords "thyroid eye disease," "diabetes mellitus," and similar terms from 2013 to 2022. The authors included relevant studies after screening the abstracts. Additional references to the selected studies were included where applicable. Data were extracted from the final articles according to the preplanned outline of the review.

RESULTS

The initial search yielded 279 abstracts. The final review included 93 articles. TED and DM interact at multiple levels-genetic, immunologic, cellular, nutritional, and metabolic. Both DM and thyroid dysfunction exacerbate the morbidity caused by the other. Metabolic factors also affect the inflammatory pathway for TED. Patients with DM develop TED with greater frequency and severity, necessitating interventions for vision salvage. Agents (GC, teprotumumab, or radiation) used for TED are often unsuitable for treatment with DM, especially if there is poor glycemic control or diabetic retinopathy. There were no studies on using steroid-sparing agents in TED with DM.

CONCLUSION

TED and DM co-exist because of multiple intersections in the pathophysiology. Challenges in the treatment include increased TED severity and risk of hyperglycemia and retinopathy. Multidisciplinary teams best undertake treatment of TED with DM.

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.

Thyroid function, sensitivity to thyroid hormones, and metabolic syndrome in euthyroid children and adolescents with Down syndrome

PURPOSE

Patients with Down Syndrome (DS) showed multiple comorbidities, including thyroid disorders, obesity, and metabolic derangement. Different thyroid hormone (THs) patterns and sensitivity to thyroid hormone indices (STHI) seem to be associated with metabolic disorders. The study's aim was to evaluate the prevalence of metabolic syndrome (MS) in pediatric patients affected by DS, taking into consideration the relationship between the metabolic parameters, THs and STHI.

METHODS

We enlisted 50 euthyroid patients with DS (9.03 ± 4.46). Clinical parameters, TSH, FT3, FT4 and the presence of MS were recorded. Indexes of peripheral sensitivity (FT3/FT4 ratio) and central sensitivity (TSH index, TSHI; TSH T4 resistance index, TT4RI; TSH T3 resistance index, TT3RI) were also detected. Thirty healthy subjects were included as a control group.

RESULTS

MS was detected in 12% of the subjects with DS. FT3, FT4, and TSH levels were higher in DS than in the control group (p < 0.01); higher levels of FT3/FT4 ratio, TSHI and TT3RI and lower TT4RI values (p < 0.01) were also detected. A significant correlation was detected between FT3 and fasting blood glucose (FBG) (R = 0.46), triglyceride (TG) (r = 0.37), total (r = 0.55) and high density lipoprotein-cholesterol (HDL-C) (r = - 0.38), diastolic blood pressure (DBP) (r = - 0.4); FT3/FT4 ratio and waist circumference (WC) (r = 0.36); TSHI and total (r = 0.30) and HDL cholesterol (r = - 0.31); TT4RI and HDL cholesterol (r = - 0.31); TT3RI and total (r = 0.39) and HDL cholesterol (r = - 032).

CONCLUSION

We confirmed a higher MS prevalence in children with DS compared to the control group. A significant association between THs, STHI, and the glucose and lipid metabolism parameters was detected supporting their role in metabolic alterations related to the DS.

Maternal pre-pregnancy obesity modifies the association between first-trimester thyroid hormone sensitivity and gestational Diabetes Mellitus: a retrospective study from Northern China

BACKGROUND

Contradictory relationships have been observed between thyroid function and gestational diabetes mellitus (GDM). Previous studies have indicated that pre-pregnancy BMI (pBMI) could modify their relationships. Few studies have illustrated the role of thyroid hormone sensitivity on GDM. We aimed to explore the effect of pre-pregnancy obesity on the association between early pregnancy thyroid hormone sensitivity and GDM in euthyroid pregnant women.

METHODS

This study included 1310 women with singleton gestation. Subjects were classified into pre-pregnancy obese and non-obese subgroups by pBMI levels with a cutoff of 25 kg/m2. Sensitivity to thyroid hormone was evaluated by Thyroid Feedback Quartile-Based Index (TFQI), Chinese-referenced parametric TFQI (PTFQI), TSH Index (TSHI) and Thyrotrophic T4 Resistance Index (TT4RI). The associations between these composite indices and GDM were analyzed using multivariate regression models in the two subgroups, respectively.

RESULTS

In pre-pregnancy non-obese group, early pregnancy TFQI, PTFQI, TSHI and TT4RI levels were higher in subjects with incident GDM compared to those without GDM (all P < 0.05). By contrast, obese women with GDM exhibited lower levels of those indices (all P < 0.05). The occurrence of GDM were increased with rising TFQI, PTFQI, TSHI and TT4RI quartiles in non-obese women ( all P for trend < 0.05), while exhibited decreased trend across quartiles of those indices in obese women (all P for trend < 0.05). Further logistic analysis indicated contrary relationships between thyroid hormone sensitivity and the occurrence of GDM in the two groups, respectively. The OR of the fourth versus the first quartile of TFQI for GDM was 1.981 (95% CI 1.224, 3.207) in pre-pregnancy non-obese group, while was 0.131 (95% CI 0.036, 0.472) in pre-pregnancy obese group. PTFQI and TSHI yielded similar results.

CONCLUSIONS

The association between maternal sensitivity to thyroid hormones during early gestation and the occurrence of GDM was modified by pre-pregnancy obesity.

Elevated Free Thyroxine Levels Might Alter the Effect of the Lipid Profile on Insulin Resistance in Type 2 Diabetes Mellitus

Previous studies have shown that hyperthyroidism is associated with heightened insulin resistance and dyslipidemia. Therefore, in this study, we aim to explore the relationship between elevated thyroid hormone levels and the lipid profile in insulin resistance in patients with type 2 diabetes mellitus (T2DM) with hyperthyroidism. A total of 177 participants were included and grouped according to diagnosis. The serum test results demonstrated that free thyroxine (FT4) increased the insulin resistance index (HOMA-IR) by positively correlating with triglyceride (TG) levels (p = 0.005, r2 = 0.35). In patients with T2DM with hyperthyroidism, the decreasing high-density lipoprotein levels showed an association with HOMA-IR (p = 0.005). Among all the patients, with different levels of FT4, the areas under the ROC curve (AUCs) of the TG level, TG/high-density lipoprotein ratio, and HOMA-IR were 0.620 (95% CI: 0.536 to 0.698), 0.614 (95% CI: 0.530 to 0.692), and 0.722 (95% CI: 0.645 to 0.791), respectively. Our results suggest that elevated FT4 levels due to hyperthyroidism could alter the association with the lipid profile and insulin resistance in patients with T2DM. We also suggest that among all the included patients with T2DM, irrespective of the presence of hyperthyroidism, FT4 levels are positively correlated with insulin resistance.

Type 2 diabetes and thyroid cancer: Synergized risk with rising air pollution

Diabetes is a complex condition, and the causes are still not fully understood. However, a growing body of evidence suggests that exposure to air pollution could be linked to an increased risk of diabetes. Specifically, exposure to certain pollutants, such as particulate Matter and Ozone, has been associated with higher rates of diabetes. At the same time, air pollution has also been linked to an increased risk of thyroid cancer. While there is less evidence linking air pollution to thyroid cancer than to diabetes, it is clear that air pollution could have severe implications for thyroid health. Air pollution could increase the risk of diabetes and thyroid cancer through several mechanisms. For example, air pollution could increase inflammation in the body, which is linked to an increased risk of diabetes and thyroid cancer. Air pollution could also increase oxidative stress, which is linked to an increased risk of diabetes and thyroid cancer. Additionally, air pollution could increase the risk of diabetes and thyroid cancer by affecting the endocrine system. This review explores the link between diabetes and air pollution on thyroid cancer. We will discuss the evidence for an association between air pollution exposure and diabetes and thyroid cancer, as well as the potential implications of air pollution for thyroid health. Given the connections between diabetes, air pollution, and thyroid cancer, it is essential to take preventive measures to reduce the risk of developing the condition.

The Impact of Hypothyroidism on Diabetes Mellitus and Its Complications: A Comprehensive Review

Diabetes mellitus (DM) is one of the most prevalent metabolic disorders in the world and is characterized by excessive blood glucose levels, which lead to deranged carbohydrate, protein, and lipid metabolisms. At its core, DM is an impairment of insulin metabolism, leading to a plethora of clinical features. The thyroid gland is another vital cog in the wheel of the endocrine system, and the hormones synthesized by it are heavily involved in the control of the body's metabolism. Hypothyroidism is a state in which thyroid hormones are deficient due to various factors and is characterized by a metabolically hypoactive state. Together, insulin, implicated in DM, and thyroid hormones engage in an intricate dance and serve to regulate the body's metabolism. It is imperative to explore the relationship between these two common endocrine disorders to understand their clinical association and mold treatments specific to patients in which they coexist. Both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have been shown to have an increased association with hypothyroidism, especially in patients with risk factors including female sex, hyperlipidemia, obesity, and anemia. This review also explores DM's macrovascular and microvascular complications and their association with hypothyroidism. It is of great use to screen for hypothyroidism in diabetic patients. Specific protocols, especially for patients at an elevated risk, provide improved quality of life to patients affected by this highly prevalent disease.

Ultrasonographic & biochemical analysis of thyroid bio-architecture for further pharmacological intervention in adult Arabian stallions & mares

Based on the growing attention to the Arabian horses with a lack of records regarding their normal physiological parameters, which are critically vital for disease diagnosis &convenient drug administration, we give great attention to their thyroid gland normalcy. The thyroid gland is one of the key players in regulating many physiological processes. Therefore, we tackled thyroid biology & morphology in 14 Arabian stallions & 18 Arabian mares from the beginning of March to the middle of April on animals from 4 to 19 years old. First, the blood samples taken from their jugular vein were used for hematological profile, lipid profile, glucose-coagulation axis & thyroid profile. Moreover, thyroid gland dimensions & volume were estimated using ultrasonography. Noteworthy, Arabian mares have significantly higher MCH & relative eosinophils than Arabian stallions, while Arabian stallions have significantly higher glucose levels than Arabian Mares. Interestingly, this study found that Arabian horses have a high level of Total T4 & low level of platelets count compared to other horses. These results pointed to the deiodinase inhibitors as a possible target therapy for hyperthyroidism & thyroid cancer in Arabian horses, making surgery a second option. Also, these results refer to the caution required before giving Arabian horses high plasma protein bounded drugs, especially anticoagulants. Also, sonographic results showed that the left lobe is larger than the right lobe in both genders, & the lobes volume is larger in Arabian horses compared to others. These results would guide the veterinarian during diagnosis & thyroidectomy.

Cancer and Mortality Risks of Graves' Disease in South Korea Based on National Data from 2010 to 2019

Purpose

This study aimed to investigate Graves' disease (GD) associated cancer and mortality risk using a Korean population-based study.

Patients and Methods

We included 6435 patients with GD using the Korean National Health Insurance Service-National Sample Cohort database from 2010 to 2019. Data concerning such patients were compared in a 1:5 ratio with age- and sex-matched non-GD group (n=32,175). Eighteen subdivided types of cancer and cancers-in-total were analyzed. In addition to the mortality analysis, subgroup analyses were performed according to age and sex.

Results

After adjustment, the hazard ratio (HR) of the GD group for cancer-in-total was 1.07 (95% confidence interval [CI], 0.91-1.27), showing no difference when compared to the non-GD group. However, among different types of cancer, the thyroid cancer risk of the GD group was higher than that of the non-GD group (HR=1.70; 95% CI, 1.20-2.39). When subdivided by age and sex, the thyroid cancer risk of the GD group in males aged 20-39 years was higher than that of the non-GD group (HR=7.00; 95% CI, 1.48-33.12). The mortality risk of the GD group was not different from that of the non-GD group (HR=0.86; 95% CI, 0.70-1.05).

Conclusion

In South Korea, patients with GD had a higher risk of thyroid cancer than the non-GD group. In particular, males aged 20-39 years with GD were more likely to have thyroid cancer than the non-GD group.

The association of diabetes, subclinical hypothyroidism and carotid intima-media thickness: results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brazil)

INTRODUCTION

The association of diabetes with subclinical thyroid diseases may increase the risk of cardiovascular diseases. We analyzed the association of subclinical hypothyroidism, diabetes, and both diseases with carotid Intima-Media Thickness (cIMT) as a surrogate maker for early cardiovascular disease in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

Cross-sectional analysis with data from the 3^rd visit (2017‒2019). Linear regression models were used to evaluate the association of subclinical hypothyroidism, diabetes and of both diseases with a cIMT presented as Beta (95% Confidence Interval ‒ 95% CI) without adjustment, with adjustment for sociodemographic variables (Model 1) and multivariable adjustment (Model 1 more cardiovascular risk factors). We also used logistic regression models to analyze the Odds Ratio (OR) and 95% CI for the association of both diseases using cIMT > P75%.

RESULTS

After the exclusion of patients with previous cardiovascular disease, 5,077 participants with no diseases, 1578 with diabetes, 662 with subclinical hypothyroidism, and 234 with both diseases were included in the analysis. Linear regression models showed an association of cIMT with only diabetes (β = 0.019; 95% CI 0.012 to 0.027; p < 0.0001) and subclinical hypothyroidism more diabetes (β = 0.03; 95% CI 0.010‒0.047, p < 0.0001). The logistic regression model reported an association between diabetes and CIMT higher than P75% (OR = 1.49, 95% CI 1.30‒1.71). No interaction between diabetes and subclinical hypothyroidism was detected using cIMT respectively as a continuous (p = 0.29) or as a categorical variable (p = 0.92).

DISCUSSION

Diabetes was associated with higher cIMT values. However, no additive effect of subclinical hypothyroidism associated with diabetes over cIMT was detected.

Retrospective cohort analysis comparing changes in blood glucose level and body composition according to changes in thyroid-stimulating hormone level

BACKGROUND

In the euthyroid state, the risk of developing diabetes according to changes in thyroid-stimulating hormone (TSH) levels remains controversial. Additionally, the correlation of various body indices affecting blood glucose levels according to changes in TSH levels over a certain period is not well known.

METHODS

Patients who underwent health check-ups twice at a 2 year interval at a tertiary university hospital between 2009 and 2018 were included. By dividing baseline TSH levels into quartiles (TSH_Q1, Q2, Q3, and Q4), various variables were compared, and their changes after 2 years (∆TSH_Q1, Q2, Q3, and Q4) were confirmed.

RESULTS

Among 15 557 patients, the incidence of diabetes mellitus after 2 years was 2.4% (377/15 557 patients). There was no statistically significant difference in the incidence of diabetes according to TSH_Q (p = 0.243) or ∆TSH_Q (p = 0.131). However, as TSH levels increased, skeletal muscle mass decreased (p < 0.001), and body fat mass and percent body fat significantly increased (p < 0.001). As ∆TSH increased, ∆fasting blood glucose and ∆body mass index also significantly increased (all p < 0.001). The incidence of diabetes decreased significantly as skeletal muscle mass increased (odds ratio 0.734, p < 0.001).

CONCLUSIONS

Owing to the short study period, it was not possible to prove a statistical relationship between the incidence of diabetes mellitus and TSH levels in the euthyroid state. Significant decreases in skeletal muscle mass and increases in body mass index and body fat mass according to baseline TSH levels were demonstrated. Therefore, a focus on improving physical functions, such as increasing muscle mass and decreasing fat, is required in this case.

Clinical significance of hepatic function in Graves disease with type 2 diabetic mellitus: A single-center retrospective cross-sectional study in Taiwan

Graves disease (GD) and type 2 diabetes mellitus (T2DM) both impair liver function; we therefore explored the possibility of a relationship among diabetic control, thyroid function, and liver function. This retrospective, cross-sectional study compared serum liver function biomarkers of primary GD patients in a single center between 2016 and 2020, derived from clinical databases, and clarified the correlation of liver function in GD patients with or without T2DM. Furthermore, the diabetes mellitus group was divided into glycated hemoglobin A1C (HbA1C) <6.5% group and ≥6.5% group to further analyze the effect by disease control in patients. Statistical differences between groups were assessed using independent t tests to clarify the association of serum biomarkers between GD with T2DM. Pearson test was applied to assess within-group statistical correlation of serum biomarkers. The correlation of factors in each group was demonstrated by using the Kendall tau-b method and stepwise regression analysis. A total of 77 patients were included in the study. In the study population, glutamate pyruvate transaminase (GPT) was significantly correlated with thyroid-stimulating hormone, and HbA1C was significantly correlated with alkaline phosphatase (ALK-P), glutamate oxaloacetate transaminase (GOT), and GPT. An examination of GOT, GPT, free thyroxine (FT4), and HbA1C levels revealed a significant difference between the non-T2DM and T2DM groups. GPT also exhibited a significant correlation with triiodothyronine in the T2DM group. The T2DM group was further divided into groups: HbA1C <6.5% and ≥6.5%. The results demonstrated that ALK-P, GOT, GPT, and FT4 levels were significantly different between the groups. A significant correlation between ALK-P and thyroid-stimulating hormone and between GOT and FT4 was also identified in the HbA1C <6.5% group. Our single-center study revealed that diabetes affects liver function in patients with GD. For patients with T2DM, when liver function becomes impaired, thyroid function control deteriorates. GPT was correlated with triiodothyronine but not with FT4, which indicated the impairment of deiodination in the liver. This phenomenon was not observed in the non-T2DM population. The early detection of abnormal liver function in patients with GD and T2DM may help limit the development of comorbidities and improve disease management.

Oxidative Stress and DNA Damage in Peripheral Blood Mononuclear Cells from Normal, Obese, Prediabetic and Diabetic Persons Exposed to Thyroid Hormone In Vitro

Diabetes, a chronic group of medical disorders characterized byhyperglycemia, has become a global pandemic. Some hormones may influence the course and outcome of diabetes, especially if they potentiate the formation of reactive oxygen species (ROS). There is a close relationship between thyroid disorders and diabetes. The main objective of this investigation was to find out whether peripheral blood mononuclear cells (PBMCs) are more prone to DNA damage by triiodothyronine (T₃) (0.1, 1 and 10 μM) at various stages of progression through diabetes (obese, prediabetics, and type 2 diabetes mellitus—T2DM persons). In addition, some biochemical parameters of oxidative stress (catalase-CAT, thiobarbituric acid reactive substances—TBARS) and lactate dehydrogenase (LDH) were evaluated. PBMCs from prediabetic and diabetic patients exhibited increased sensitivity for T₃ regarding elevated level of DNA damage, inhibition of catalase, and increase of TBARS and LDH. PBMCs from obese patients reacted in the same manner, except for DNA damage. The results of this study should contribute to a better understanding of the role of thyroid hormones in the progression of T2DM.

Circulating free triiodothyronine concentration is positively associated with β-cell function in euthyroid patients with obesity and type 2 diabetes

OBJECTIVE

To investigate the relationship between thyroid hormone concentrations and β-cell function in euthyroid patients with obesity and type 2 diabetes.

METHODS

We performed a single-center cross-sectional study of 254 patients with type 2 diabetes mellitus aged ≥40 years. The participants were allocated to an obesity group or non-obesity group on the basis of their body mass index (BMI). Their β-cell function was assessed by measuring C-peptide concentration during a 75-g oral glucose tolerance test (OGTT); and their serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone concentrations were measured.

RESULTS

The serum FT3 concentration and the C-peptide concentrations at five time points of the OGTT were significantly higher in the obesity group than in the non-obesity group. FT3 was positively associated with the β-cell function of the obesity group, but not that of the non-obesity group, in multiple linear regression analysis, after adjustment for potential confounding factors. Serum FT3 concentration was also significantly associated with indices of obesity (BMI, waist circumference, body fat percentage, fat mass, fat mass/height² and visceral fat area).

CONCLUSIONS

Obesity-associated high serum FT3 concentrations might affect β-cell function in euthyroid patients with obesity and type 2 diabetes.

Tpo knockout in zebrafish partially recapitulates clinical manifestations of congenital hypothyroidism and reveals the involvement of TH in proper development of glucose homeostasis

Congenital hypothyroidism (CH) is a highly prevalent but treatable neonatal endocrine disorder. Thyroid peroxidase (TPO) catalyzes key reactions in thyroid hormone (TH) synthesis. TPO mutations have been found to underlie approximately 5% of congenital hypothyroidism in Chinese patients with more severe phenotypes, the treatment of whom usually requires a higher dose of L-thyroxine. The Tpo gene of zebrafish has 66% homology with the human TPO gene, and synteny analysis has indicated that it is likely a human TPO ortholog. In this study, we generated a tpo^-/- mutant zebrafish line through knockout of tpo with CRISPR/Cas9 and investigated the associated phenotypes. Tpo^-/- mutant zebrafish displayed growth retardation; an increased number of thyroid follicular cells; and abnormal extrathyroidal phenotypes including pigmentation defects, erythema in the thoracic region, delayed scale development and failure of swim bladder secondary lobe formation. All these abnormal phenotypes were reversed by 30 nM thyroxine (T4) treatment starting at 1 month of age. Tpo^-/- mutants also showed increased glucose levels during larval stages, and the increases were induced at least in part by increasing glucagon and decreasing insulin expression. Our work indicates that tpo-mutant zebrafish may serve as a human congenital hypothyroidism model for studying TPO- and TH-related disease mechanisms.

Thyroid Function and the Risk of Prediabetes and Type 2 Diabetes

CONTEXT

Thyroid hormones are important regulators of glucose metabolism, and studies investigating the association between thyroid function and type 2 diabetes incidence have shown conflicting results.

OBJECTIVE

We aimed to combine the evidence from prospective studies addressing the association between thyroid function and type 2 diabetes risk.

METHODS

We systematically searched in Embase, Medline (Ovid), Web of Science, Cochrane, and Google Scholar for prospective studies assessing the association of thyroid function and incident type 2 diabetes. Data extraction was performed using a standardized protocol by 2 independent reviewers. We assessed study quality using the Newcastle-Ottawa Scale and pooled hazard ratios (HRs) and 95% CI using random-effects models.

RESULTS

From the 4574 publications identified, 7 met our inclusion criteria and were included in the qualitative synthesis. Six publications were included in the meta-analysis. Studies assessed hypothyroidism (6 studies), hyperthyroidism (5 studies), thyrotropin (TSH) in the reference range (4 studies), and free thyroxine (FT4) in the reference range (3 studies) in relation to incident type 2 diabetes. The pooled HR for the risk of type 2 diabetes was 1.26 (95% CI, 1.05-1.52) for hypothyroidism, 1.16 (95% CI, 0.90-1.49) for hyperthyroidism, 1.06 (95% CI, 0.96-1.17) for TSH in the reference range, and 0.95 (95% CI, 0.91-0.98) for FT4 in the reference range.

CONCLUSION

Current evidence suggests an increased type 2 diabetes risk in people with hypothyroidism and lower FT4 levels in the reference range. Further population-based studies are needed to address this association given the limited evidence.

Impact of urinary iodine concentration on blood glucose levels and blood pressure: a nationwide population-based study

PURPOSE

Iodine is a vital trace element for systemic metabolic control as well as thyroid hormone synthesis. Though iodine has significant antioxidant and anti-inflammatory effects, reports on its effects on metabolic disorders are limited and inconsistent.

METHODS

Impact of urinary iodine concentrations (UICs) on fasting blood glucose (FBG) levels and blood pressure (BP) in the general Korean population was evaluated adjusting for covariates including thyrotropin level and presence of thyroid diseases.

RESULTS

The median UIC was 302.3 μg/L in all participants and was significantly lower in those with dysglycemia (303.6 μg/L in normal participants, 285.1 μg/L in participants with FBG levels of 100-125 mg/dL, and 261.8 μg/L in participants with FBG levels ≥ 126 mg/dL; p = 0.002). Similarly, the UIC was lower in participants with higher BP (311.6 μg/L in normal participants, 288.7 μg/L in prehypertensive participants, and 265.8 μg/L in hypertensive participants; p < 0.001). The multiple linear regression model showed a negative correlation between the UIC and FBG levels (p = 0.002), and the UIC and systolic BP (p < 0.001). One standard deviation increase in the UIC showed odds ratios of 0.84 (95% confidence interval [CI] = 0.73-0.98) for elevated FBG levels (≥ 100 mg/dL) and 0.94 (95% CI = 0.88-0.99) for elevated SBP (≥ 120 mm Hg) after full adjustment.

CONCLUSION

Higher UICs were associated with lower FBG and BP levels, independent of thyroid function and other confounding factors in Korea, an iodine-replete country.

Association of thyroid function with insulin resistance: data from two population-based studies

OBJECTIVE

Thyroid dysfunction is associated with relevant disturbances in glucose metabolism. Moreover, thyroid function undergoes important changes with ageing. The objective of this study was to investigate the association of thyroid function with insulin resistance with particular consideration of possible age-related effect modifications.

DESIGN

A sample of 4193 participants from two independent epidemiological studies, the Study of Health in Pomerania-TREND-0 and the Berlin Aging Study II, was included in this cross-sectional analysis.

METHODS

Insulin resistance was estimated by homeostasis model of insulin resistance (HOMA-IR) and the insulin sensitivity index (ISI). Associations of thyroid biomarkers (thyroid-stimulating hormone, free thyroxine, and free triiodothyronine (fT3)) with parameters of glucose metabolism were analysed by regression models adjusted for age, sex, smoking status, and study site.

RESULTS

A higher fT3 was significantly associated with higher fasting glucose and higher fasting and 2-h postload insulin levels, a higher HOMA-IR, and lower ISI. A higher fT3 was also associated with a higher risk for impaired fasting glucose (RR 1.09, 95 CI 1.02; 1.18; P = 0.017). Many of these associations between thyroid markers and parameters of glucose metabolism were significant in young and middle-aged participants but not in older individuals.

CONCLUSIONS

The main finding of this study was a consistent association of fT3 with almost all markers of insulin resistance. However, this effect seems to be wearing off in higher age highlighting a potential age-related modification of the interaction between thyroid function and glucose metabolism. Further studies are needed to clarify causal relationships.

Evaluation of Factors Affecting Thyroid Levels and its Relationship with Salt Iodine to Suggest the Way Forward!

Background:

In India, 42 million people suffer from thyroid diseases. One in 10 adults suffer from hypothyroidism. Although coverage of iodized salt utilization has increased after universal salt iodization, we are yet to achieve the goals of NIDDCP for which the present study was planned to identify the hidden factors. The aim is to identify the factors affecting thyroid hormone levels, their association with salt iodine content and suggest strategies for improvement based on patient perceptions.

Methods:

A hospital based prospective follow up study was conducted among 140 patients, with an in depth interview and testing of salt iodine content. Data were analyzed using the SPSS software.

Results:

96 (69%) patients were of age 18–35 years. 129 (92%) were females, 120 (86%) were from rural areas, 95 (68%) were literate, 116 (83%) were unemployed, and 115 (82%) were of low socioeconomic status. Most of them had poor cooking practices and dietary habits. The T3, T4, and TSH levels were within the normal range in 84 (60%) patients. Only in 28 (20%) salt samples, the iodine content was adequate. The association between factors like intake of inadequately iodized salt (P < 0.01), rural distribution (P < 0.05), illiteracy, presence of the comorbid conditions (P < 0.0001), and thyroid hormone abnormality was found to be statistically significant.

Conclusion:

The factors that adversely affect thyroid levels were higher age, female gender, rural distribution, comorbid conditions and patients with low salt iodine were prone to abnormal levels. Monitoring salt iodine content, training of health care workers to create awareness were the key strategies proposed for improvement.

Correlation of thyroid-related hormones with vascular complications in type 2 diabetes patients with euthyroid

BACKGROUND

This study aimed to evaluate the relationship between thyroid-related hormones and vascular complications in type 2 diabetes mellitus (T2DM) patients with euthyroidism.

METHODS

We enrolled 849 patients with T2DM after screening out the ineligible. Multivariate logistic regression was used to analyze the relationship between fT3, fT4, the fT3/fT4 ratio, thyroid-stimulating hormone, and diabetic vascular complications. Spearman correlation analysis was used to determine the correlation between thyroid-related hormones and vascular complications.

RESULTS

In this cross-sectional study of T2DM, 538 patients with carotid atherosclerosis (CA) and 299 patients with diabetic peripheral neuropathy (DPN). The prevalence of DPN was negatively correlated with fT3 and the fT3/fT4 ratio but positively correlated with fT4 (all P<0.01). At the same time, the odds ratio for DPN decreased with increasing fT3 (T1: reference; T2: OR: 0.689, 95%CI: 0.477, 0.993; T3: OR: 0.426, 95% CI: 0.286, 0.633, all P<0.05) and fT3/fT4 ratio (T1: reference; T2: OR: 0.528, 95% CI: 0.365, 0.763; T3: OR: 0.413, 95% CI: 0.278, 0.613, all P<0.001). In terms of sensitivity and specificity, fT4 was found to be 39.5% and 71.4% accurate, respectively, with a 95% CI of 0.531-0.611.

CONCLUSIONS

We found a negative correlation between fT3 and fT3/fT4 ratio and the number of individuals with DPN, and a positive correlation between fT4 and the prevalence of DPN.

Evaluation of the Thyroid Characteristics and Correlated Factors in Hospitalized Patients with Newly Diagnosed Type 2 Diabetes

BACKGROUND

Diabetes mellitus (DM) and thyroid dysfunction (TD) are two closely associated disorders. The objective of the present study was to investigate the thyroid status and the relationships between thyroid hormones, diabetic complications and metabolic parameters in hospitalized patients with newly diagnosed type 2 DM (T2DM).

METHODS

This was an observational cross-sectional study, conducting on 340 patients with newly diagnosed T2DM who were admitted to ward of endocrinology department and 120 matched individuals without diabetes. Anthropometric, clinical and biochemical data were collected. Spearman correlation coefficients were calculated to evaluate the correlations between thyroid hormones and other variables. Factors associated with diabetic nephropathy (DN) was analyzed with multivariate logistic regression.

RESULTS

Levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) were significantly lower in patients with T2DM as compared to control group without diabetes. The prevalence of TD was 21.2% in patients with diabetes, higher than that in controls (4.2%). The low T3 syndrome was the most frequent TD, shown in 14.7% of patients. The presence of diabetic complications DN, diabetic ketosis or ketoacidosis), metabolic and demographic factors, including age, glycemic control and insulin resistance were factors significantly associated with levels of thyroid hormones. FT3 level was inversely correlated with the level of urinary total protein (mg/24h) and the presence of DN. Multivariate analysis indicated low FT3 level as a strong independent risk factor (OR = 0.364, P = 0.001) for DN.

CONCLUSION

TD is not rarely seen in hospitalized patients with newly diagnosed T2DM. Diabetic complications and diabetes-related metabolic and demographic factors are related to thyroid hormone levels. Decreased FT3 is strongly correlated with the presence of DN.

The progression of secondary diabetes: A review of modeling studies

Mathematical modeling has provided quantitative information consistent with experimental data, greatly improving our understanding of the progression of type 1 and type 2 diabetes. However, diabetes is a complex metabolic disease and has been found to be involved in crosstalk interactions with diverse endocrine diseases. Mathematical models have also been developed to investigate the quantitative impact of various hormonal disorders on glucose imbalance, advancing the precision treatment for secondary diabetes. Here we review the models established for the study of dysglycemia induced by hormonal disorders, such as excessive glucocorticoids, epinephrine, and growth hormone. To investigate the influence of hyperthyroidism on the glucose regulatory system, we also propose a hyperthyroid-diabetes progression model. Model simulations indicate that timely thyroid treatment can halt the progression of hyperglycemia and prevent beta-cell failure. This highlights the diagnosis of hormonal disorders, together withblood sugar tests, as significant measures for the early diagnosis and treatment of diabetes. The work recapitulates updated biological research on the interactions between the glucose regulatory system and other endocrine axes. Further mathematical modeling of secondary diabetes is desired to promote the quantitative study of the disease and the development of individualized diabetic therapies.

Impact of Quercus infectoria Galls Extract on Thyroid Gland and Testicular Functions in Diabetic Rats

Diabetes mellitus has been reported to be accompanied by thyroid and testicular dysfunctions. The objective of this study was to investigate the effect of Quercus infectoria galls (QIg) extract on the thyroid gland and testicular functions in diabetic rats. Sixteen rats were randomly divided into four equal groups, consisting of normal control, diabetic untreated control, diabetic treated with oral administration of 500 mg/kg BW and 1000 mg/kg BW, respectively for 15 days. Serum blood glucose, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), testosterone (T), and luteinizing hormone (LH) were assessed. At the end of the experimental period, the rats were euthanized for histopathological analysis of thyroid gland and testis. Furthermore, immunohistochemistry was used to assess the expression of thyroid transcription factor-1 (TTF-1) in the thyroid gland of rats. The significant increase in serum blood glucose level in diabetic rats (DC) was markedly decreased by treatment with QIg extract (500 mg and 100 mg/kg BW) almost to the normal level. The reduced thyroid hormones, both the T3 and T4 were significantly recovered after 15 days of treatment with QIg extract (500 mg and 100 mg/kg BW). Whereas serum concentration of testosterone was significantly reduced in diabetic rats with QIg extract (500 mg and 100 mg/kg BW) treatment. Histopathological analysis of diabetic rats showed a wide range of morphological alterations in thyroid gland and testicular structures, which were almost completely, restored back to normal by treatment of rats with QIg extract. Furthermore, results showed overexpression of TTF-1 in the thyroid gland of diabetic rats, which was recovered back to normal expression after 15 days of treatment with QIg extract. These findings may provide new insights into the potential role of QIg extract as a promising therapeutic agent against diabetic complications in thyroid gland and testicular functions.

Association between per- and polyfluoroalkyl substances and risk of gestational diabetes mellitus

BACKGROUND

Existing evidence suggests that perfluoroalkyl and polyfluoroalkyl substances (PFASs) exposure might contribute to the incidence of gestational diabetes mellitus (GDM). This study aimed to perform a meta-analysis to identify the association between PFAS and the risk of GDM.

METHODS

We systematically searched PubMed, Ovid, Cochrane Library, and Web of Science databases for appropriate articles about the association between PFASs exposure and the risk of GDM before September 28, 2020. Odds ratios (OR) with 95% confidence intervals (CIs) were summarized by Stata 16.0 through fixed effect models according to heterogeneity. We also carried out subgroup analyses by geographic location, blood sampling time of subjects, method of chemical analysis, study design, sample size, and sampling year. In addition, a sensitivity analysis was conducted to explore the robustness of the results.

RESULTS

A total of eight studies involving 5654 pregnant women were included in the meta-analysis. Perfluorooctanoic acid (PFOA) exposure was positively and significantly associated with the risk of GDM (OR = 1.27, 95% CI: 1.02-1.59). Exposure to other types of PFASs such as perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA) was not statistically significantly associated with the risk of GDM with the pooled effect estimates of 0.97 (95% CI: 0.86-1.09), 1.03 (95% CI: 0.86-1.24), and 0.80 (95% CI: 0.55-1.16) respectively.

CONCLUSION

We conducted a meta-analysis to investigate the association between PFASs exposure and GDM and found that PFOA concentration was significantly associated with a higher risk of GDM, which is of great significance for the prevention and control of GDM in public health. Further studies are needed in order to establish causality and clarify the potential mechanism.

Risk of Diabetes in Patients with Long-Standing Graves' Disease: A Longitudinal Study

BACKGROUND

The detrimental effects of excessive thyroid hormone on glucose metabolism have been widely investigated. However, the risk of diabetes in patients with long-standing hyperthyroidism, especially according to treatment modality, remains uncertain, with few longitudinal studies.

METHODS

The risk of diabetes in patients with Graves' disease treated with antithyroid drugs (ATDs) for longer than the conventional duration (≥2 years) was compared with that in age-and sex-matched controls. The risk was further compared according to subsequent treatment modalities after a 24-month course of ATD: continuation of ATD (ATD group) vs. radioactive iodine ablation (RIA) group.

RESULTS

A total of 4,593 patients were included. Diabetes was diagnosed in 751 (16.3%) patients over a follow-up of 7.3 years. The hazard ratio (HR) for diabetes, after adjusting for various known risk factors, was 1.18 (95% confidence interval [CI], 1.10 to 1.28) in patients with hyperthyroidism. Among the treatment modality groups, the RIA group (n=102) had a higher risk of diabetes than the ATD group (n=4,491) with HR of 1.56 (95% CI, 1.01 to 2.42). Further, the risk of diabetes increased with an increase in the ATD treatment duration (P for trend=0.019).

CONCLUSION

The risk of diabetes was significantly higher in patients with long-standing Graves' disease than in the general population, especially in patients who underwent RIA and prolonged ATD treatment. Special attention to hyperglycemia during follow-up along with effective control of hyperthyroidism may be necessary to reduce the risk of diabetes in these patients.

Associations of Habitual Mineral Intake with New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Associations between habitual dietary intake of minerals and glucose metabolism have been extensively studied in relation to metabolic disorders. However, similar research has yet to be conducted in individuals after acute pancreatitis (AP). The main aim was to investigate the associations between habitual intake of 13 minerals and glycaemic status: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Associations between the dietary intake of minerals and markers of glucose metabolism (glycated haemoglobin and fasting plasma glucose) were also studied. The EPIC-Norfolk food frequency questionnaire was used in a cross-sectional fashion to determine the habitual intake of 13 dietary minerals. ANCOVA as well as multiple linear regression analyses were conducted and five statistical models were built to adjust for covariates. The study included 106 individuals after AP. In the NODAP group, intake of 4 minerals was significantly less when compared with the NAP group: iron (B = -0.076, p = 0.013), nitrogen (B = -0.066, p = 0.003), phosphorous (B = -0.046, p = 0.006), and zinc (B = -0.078, p = 0.001). Glycated haemoglobin was significantly associated with iodine intake (B = 17.763, p = 0.032) and manganese intake (B = -17.147, p = 0.003) in the NODAP group. Fasting plasma glucose was significantly associated with manganese intake (B = -2.436, p = 0.027) in the NODAP group. Habitual intake of minerals differs between individuals with NODAP, T2DM, and NAP. Prospective longitudinal studies and randomised controlled trials are now warranted to further investigate the associations between mineral intake and NODAP.

Quantitative Structure-Activity Relationship Modeling of the Amplex Ultrared Assay to Predict Thyroperoxidase Inhibitory Activity

The thyroid system plays a major role in the regulation of several physiological processes. The dysregulation of the thyroid system caused by the interference of xenobiotics and contaminants may bring to pathologies like hyper- and hypothyroidism and it has been recently correlated with adverse outcomes leading to cancer, obesity, diabetes and neurodevelopmental disorders. Thyroid disruption can occur at several levels. For example, the inhibition of thyroperoxidase (TPO) enzyme, which catalyses the synthesis of thyroid hormones, may cause dysfunctions related to hypothyroidism. The inhibition of the TPO enzyme can occur as a consequence of prolonged exposure to chemical compounds, for this reason it is of utmost importance to identify alternative methods to evaluate the large amount of pollutants and other chemicals that may pose a potential hazard to the human health. In this work, quantitative structure-activity relationship (QSAR) models to predict the TPO inhibitory potential of chemicals are presented. Models are developed by means of several machine learning and data selection approaches, and are based on data obtained in vitro with the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay. Balancing methods and feature selection are applied during model development. Models are rigorously evaluated through internal and external validation. Based on validation results, two models based on Balanced Random Forest (BRF) and K-Nearest Neighbours (KNN) algorithms were selected for a further validation phase, that leads predictive performance (BA = 0.76-0.78 on external data) that is comparable with the reported experimental variability of the AUR-TPO assay (BA ∼0.70). Finally, a consensus between the two models was proposed (BA = 0.82). Based on the predictive performance, these models can be considered suitable for toxicity screening of environmental chemicals.

T3 as predictor of mortality in any cause non-critically ill patients

BACKGROUND

Low T3 syndrome refers to a set of thyroid hormone metabolism alterations present in the disease state. A correlation between low T3 and poor clinical outcomes in the intensive care unit is more established. Nonetheless, studies on non-critically ill patients are few and controversial.

OBJECTIVE

To evaluate the prevalence and predictive value of low T3 levels on 30-day and 6-month mortality in non-critically ill patients. Secondary outcomes evaluated the length of hospital stay, overall mortality, and hospital readmission.

DESIGN

Prospective cohort study.

METHODS

A total of 345 consecutive patients from the Internal Medicine ward of a tertiary hospital in southern Brazil were included and followed from October 2018 to April 2019 (6 months). Levels of total serum T3 were measured weekly, from admission to discharge, and correlated with 30-day and 6-month mortality.

RESULTS

Prevalence of low T3 was 36.6%. Low T3 levels were associated with higher 30-day hospital mortality (15.1% vs 4.1%, P < 0.001) and higher 6-month overall mortality (31.7% vs 13.2%, P < 0.001). Total serum T3 at admission was an independent predictor of 30-day hospital mortality.

CONCLUSION

Low T3 levels are a prevalent condition among non-critically ill patients, and this condition is associated with poor clinical outcomes in this population. Total serum T3 levels, alone or in association with other predictive scores, were demonstrated to be an easy and valuable tool for risk stratification and should be further employed in this setting.

Levothyroxine and insulin requirement in autoimmune polyglandular type 3 syndrome: a real-life study

PURPOSE

To evaluate factors influencing the insulin and levothyroxine requirement in patients with autoimmune polyglandular syndrome type 3 (APS-3) vs. patients with type 1 diabetes mellitus (T1DM) and autoimmune hypothyroidism (AH) alone, respectively.

METHODS

Fifty patients with APS-3, 60 patients with T1DM and 40 patients with AH were included. Anthropometric, clinical and biochemical parameters were evaluated in all patients. Insulin requirement was calculated in patients with APS-3 and T1DM, while levothyroxine requirement was calculated in APS-3 and AH.

RESULTS

Patients with APS-3 showed higher age (p = 0.001), age of onset of diabetes (p = 0.006) and TSH (p = 0.004) and lower total insulin as U/day (p < 0.001) and U/Kg (p = 0.001), long-acting insulin as U/day (p = 0.030) and U/kg (p = 0.038) and irisin (p = 0.002) compared to T1DM. Patients with APS-3 had higher waist circumference (p = 0.008), duration of thyroid disease (p = 0.020), levothyroxine total daily dose (p = 0.025) and mcg/kg (p = 0.006), triglycerides (p = 0.007) and VAI (p = 0.010) and lower age of onset of thyroid disease (p = 0.007) than AH. At multivariate analysis, levothyroxine treatment and VAI were associated with insulin and levothyroxine requirement in APS-3, respectively. VAI was independently associated with insulin requirement in T1DM. Circulating irisin levels were independently associated with levothyroxine requirement in AH.

CONCLUSION

Patients with APS-3 show lower insulin requirement and higher levothyroxine requirement than T1DM and AH alone, respectively. Levothyroxine treatment and VAI affect insulin and levothyroxine requirement, respectively, in APS-3. In T1DM, adipose tissue dysfunction, indirectly expressed by high VAI, is associated with an increased insulin requirement, while circulating irisin levels influence the levothyroxine requirement in AH.

Incidence of Thyroid Dysfunction Facing Metabolic Syndrome: A Prospective Comparative Study with 9 Years of Follow-Up

BACKGROUND

Studies assessing thyroid hormones in metabolic syndrome (MetS) patients are contradictory. Also, the effect of MetS on thyroid function over time is not yet evaluated. This study investigated the prevalence and incidence of thyroid dysfunction (TD) as well as time trends of thyroid hormones in subjects with and without MetS, during a 10-year follow-up in Tehranian adult population.

METHODS

This is a prospective cohort study conducted in the framework of Tehran Thyroid Study on 5,786 subjects aged ≥20 years: 4,905 eligible participants entered the study after excluding those with corticosteroid or radioactive iodine use, pregnancy, thyrotropin (TSH) <0.1 and >10 mU/L, and missing data. Physical examinations were performed and serum concentrations of TSH, free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), fasting plasma glucose, insulin, and lipid profile were assessed at baseline and 3-year intervals during the follow-up. MetS was defined according to the Joint Interim Statement Definition.

RESULTS

At baseline, there were no difference in median serum concentrations of FT4 and TSH between MetS and non-MetS group after adjusting for age, sex, BMI, smoking, and TPOAb positivity. Although there was higher risk of overt (42%) and subclinical hypothyroidism (16%) in MetS compared with non-MetS subjects, no significant difference was observed in adjusted ORs for any TD between 2 groups. There were also no significant differences in time trends of TSH, FT4, TPOAb positivity, and incidence rates of TDs between MetS and non-MetS groups during 10 years, after adjustment for age, sex, BMI, smoking status, and TPOAb positivity.

CONCLUSION

MetS is not associated with thyroid hypofunction considering other important confounders such as age, sex, smoking, BMI, and TPOAb positivity. There is also no difference in the trend of thyroid hormones and incidence of TD between MetS and non-MetS subjects during a 10-year follow-up.

Genetically Determined Higher TSH Is Associated With a Lower Risk of Diabetes Mellitus in Individuals With Low BMI

CONTEXT

Thyroid status is hypothesized to be causally related with the risk of diabetes mellitus (DM), but previous results were conflicting possibly because of a complex interaction between thyrotropin (TSH), body mass index (BMI) and DM.

OBJECTIVE

This work aims to investigate the causal association between thyroid status with DM and glucose homeostasis and to what extent this association is dependent on BMI.

METHODS

A mendelian randomization study was conducted of European-ancestry participants from the UK Biobank population. The present study involved 408 895 individuals (mean age 57.4 years [SD 8.0], 45.9% men), of whom 19 773 had DM. Genetic variants for circulatory TSH, free thyroxine (fT4) concentrations and BMI to calculate weighted genetic risk scores. The main outcome measures included self-reported DM-stratified analyses by BMI. Analyses were repeated for nonfasting glucose and glycated hemoglobin A1c (HbA1c) among individuals without DM.

RESULTS

Genetically determined TSH and fT4 levels were not associated with risk of DM in the total UK Biobank population. However, in analyses stratified on genetically determined BMI, genetically determined higher TSH, and not fT4, was associated with a lower risk for DM only in the low BMI group (odds ratio 0.91; 95% CI, 0.85-0.98 in low BMI; P value for interaction = .06). Similar results were observed for glucose and HbA1c among individuals without DM.

CONCLUSION

TSH, but not fT4, is a potential causal risk factor for DM in individuals with genetically determined low BMI highlighting potential protective effects of TSH only in low-risk populations.

The Predictive Role of Thyroid Hormone Levels for Early Diabetic Retinal Changes in Experimental Rat and Human Diabetes

Purpose

In diabetic subjects, early visual functional alterations such as color vision deficiencies (CVDs) are known to precede clinically apparent diabetic retinopathy. Prominent photoreceptor outer segment degeneration and an increase in the number of retinal dual cones (co-expressing S- and M-opsins simultaneously) have been described in diabetic rat models, suggesting a connection with the development of CVDs. As cone opsin expression is controlled by thyroid hormones, we investigated the diabetic retina in association with thyroid hormone alterations.

Methods

In rat models of type 1 and 2 diabetes, dual cones were labeled by immunohistochemistry, and their numbers were analyzed in relation to free triiodothyronine (fT3) and free thyroxine (fT4) levels. Quantification of dual cones was also performed in human postmortem retinas. Additionally, a cross-sectional case–control study was performed where thyroid hormone levels were measured and color vision was assessed with Lanthony desaturated D15 discs.

Results

A higher number of dual cones was detectable in diabetic rats, correlating with fT4 levels. Dual cones were also present in postmortem human retinas, with higher numbers in the three diabetic retinas. As expected, age was strongly associated with CVDs in human patients, and the presence of diabetes also increased the risk. However, the current study failed to detect any effect of thyroid hormones on the development of CVDs.

Conclusions

Our results point toward the involvement of thyroid homeostasis in the opsin expression changes in diabetic rats and human samples. The evaluation of the possible clinical consequences warrants further research.

Severity of thyroid eye disease and type-2 diabetes mellitus: Is there a correlation?

Purpose

To study the correlation between thyroid eye disease (TED) with type-2 diabetes mellitus.

Methods

A cross-sectional cohort study was conducted from Jan 2018 to Dec 2018, in patients presenting with thyroid eye disease to orbit and oculoplasty clinic of a tertiary eye care hospital. A total of 105 patients were included in the study. All patients underwent detailed ophthalmic evaluation and thyroid eye disease workup. Patients were categorized into mild, moderate, and severe/sight-threatening TED based on EUGOGO classification. Systemic history of diabetes was noted. RBS was done in all patients.

Results

Mild disease was noted 61 patients of which 11 were diabetics, moderate in 26 patients (8 diabetics), and severe disease in 18 patients (14 diabetics). All patients were treated accordingly. Among the TED patients, the percentage of diabetic patients was noted to be in increasing order toward the severity spectrum of TED. The prevalence of severe TED was found to be much higher in diabetic patients accounting upto 77.77% of 18 patients. A statistically significant correlation was noted (P = 0.014) between severe TED and type-2 diabetes mellitus. In addition, early onset of thyroid eye disease was noted in type-2 diabetes patients. Even though female preponderance was noted, severe TED was more in men (66.6%).

Conclusion

An autoimmune etiology for the association of thyroid and type-1diabetes has been well established. This study shows that type-2 diabetic patients can have more severity in the clinical presentation of TED. Therefore, the presence of type-2 DM in patients with TED can be a predictive factor for onset, progression, and severity of disease. Hence, a high concern of interest among treating ophthalmologists and endocrinologists regarding this entity would help in early prediction and decreased morbidity among such patients.

A longitudinal study of thyroid markers during pregnancy and the risk of gestational diabetes mellitus and post-partum glucose metabolism

AIMS

To determine the relationship between thyroid markers during pregnancy and gestational diabetes mellitus (GDM) or post-partum glucose metabolism.

MATERIALS AND METHODS

Based on pregnancy 75-g oral glucose tolerance test (OGTT) results, 1467 subjects were grouped into normal glucose tolerance (NGTp; n = 768) and GDM (n = 699) groups. Furthermore, based on post-partum 75-g OGTT results, 286 GDM subjects, screened for glucose metabolism after delivery, were grouped into NGTd (n = 241) and abnormal glucose tolerance (AGT; n = 45) groups.

RESULTS

Maternal age, family history of diabetes, acanthosis nigricans, previous adverse pregnancy outcomes and caesarean section incidence, and thyroid positive antibody rates were higher in the GDM group than in the NGTp group. In the first trimester, free triiodothyronine (FT3), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) levels were higher in the GDM group than in the NGTp group. In the second trimester, free thyroxine (FT4) levels were lower and TPOAb and TgAb levels were higher in the GDM group than in the NGTp group. After adjusting for confounding factors, FT3, TPOAb and TgAb (first trimester), and FT4, TPOAb and TgAb (second trimester) were risk factors for GDM. TPOAb and TgAb levels were higher in the AGT group than in the NGTd group and were potential predictors of abnormal post-partum glucose tolerance.

CONCLUSIONS

GDM risk significantly increased with increased FT3 (first trimester), TPOAb and TgAb (first and second trimesters) or with decreased FT4 (second trimester). Presence of thyroid antibodies predicted post-partum glucose abnormalities in subjects with GDM.

Thymoquinone Preserves Pancreatic Islets Structure Through Upregulation of Pancreatic β-Catenin in Hypothyroid Rats

BACKGROUND

Altered status of thyroid hormones, which have a key role in regulating metabolism, was reported to affect glucose homeostasis and insulin secretion.

OBJECTIVE

This study was designed to assess the impact of propylthiouracil (PTU)-induced hypothyroidism on the pancreatic islet cells and the efficacy of thymoquinone (TQ) in alleviating this impact and explore the mechanism behind it alleviating oxidative stress and affecting β-catenin expression.

MATERIALS AND METHODS

PTU (6 mg/kg/body weight) was used to induce hypothyroidism in Wistar rats. Four groups of rats (n=6 each) were utilized in this study. Untreated hypothyroid and TQ-treated hypothyroid groups (50 mg/kg/body weight for 4 weeks) were included. Thyroid functions, antioxidant profile and pancreatic β-catenin and IL-10 mRNA were measured. Histopathological and immunohistochemical assessment of the pancreas was performed.

RESULTS

PTU administration induced a hypothyroid status that was associated with a marked disturbed oxidant/antioxidant status and a significant hyperglycemia (p<0:001), hypoinsulinemia (p=0.01) and decreased HOMA-β-cell (p<0.001). Islet cells of hypothyroid pancreas showed many degenerative changes with increased apoptosis, reduced insulin β-catenin immunoexpression. Administration of TQ alleviated these effects on the thyroid function, antioxidants, structure of pancreatic islet cells. Up-regulation of β-catenin, IL-10 and CAT gene expression in pancreatic islets after treatment with TQ supported its antioxidant and preserving β-cell function and viability mechanistic action.

CONCLUSION

TQ alleviated PTU-induced hypothyroidism changes in insulin homeostasis and pancreatic β cells mostly through its antioxidant effect as well as up-regulation of pancreatic β-catenin expression.

Pattern of Disease and Therapy for Diabetes along with Impact of Generic Prescribing on Cost of Treatment among Outpatients at a Tertiary Care Facility

Background:

India has become the diabetes capital of the world. Analyzing trends in drug prescribing helps in judging rationality of prescriptions in different settings. This study aimed to assess disease and prescribing trends with a special emphasis on evaluating use of metformin, insulin, fixed dose combinations (FDCs), concomitant medications, pill burden, and costs of drug therapy in diabetes.

Materials and Methods:

This was a cross-sectional study in which patients of either sex who attended the diabetes clinic at a tertiary care center over 9 months were included consecutively. Basic demographic profile, clinical, and treatment details on the day of visit were collected from the prescription charts. Drug costs for prescriptions were calculated using generic and median brand prices of formulations using a recognized commercial drug directory and generic price list of the government, respectively. Data were analyzed by using Microsoft Excel and Open Epi online software to compare results with published studies.

Results:

Average age of diabetics was 53.9 ± 11.8 years and disease duration was 8.13 ± 7.78 years in 336 prescriptions analyzed. Dual drug regimens were seen in 32.7% prescriptions, most commonly metformin and sulfonylureas, followed by triple drug regimens (25%) with inhibition of dipeptidyl peptidase IV (DPP IV) inhibitor. Metformin was prescribed in 95% prescriptions (mean dose 1511 ± 559.87 mg) and insulin in 22.6% prescriptions. Angiotensin receptor blocker (ARBs) and statins were the most commonly prescribed concomitant drugs. One FDC per prescription (median) each for diabetes and comorbidities were prescribed. Daily pill burden was 4.59 ± 2.65 pills. The median monthly cost of drug therapy with branded prescribing was INR 870.43 and INR 393.72 with the use of generics. Inferences drawn by comparison with published data showed variable results for different parameters analyzed.

Conclusion:

Disease pattern was as expected for the region and trends of therapy showed concurrence with rational prescribing. Pill burden and cost of therapy remain high with a significant contribution of comorbidities.

Diabetes and subclinical hypothyroidism on heart rate variability

BACKGROUND

We aimed to analyse if the effects of coexistent diabetes and subclinical hypothyroidism extend to the cardio autonomic nervous system, using heart rate variability baseline data from the Brazilian Longitudinal Study of Adult Health.

MATERIALS AND METHODS

Heart rate variability analyses were performed by linear time and frequency domains in 5-minute time series collected in the supine position. The associations of diabetes and subclinical hypothyroidism with the lowest quartile group for heart rate and the highest quartile group for each heart rate variability parameter were analysed using additive and multiplicative terms in logistic models. For the first approach, the subsample was categorized into four groups: subjects without diabetes and normal thyroid function (controls); subjects without diabetes and subclinical hypothyroidism; patients with diabetes and normal thyroid function; and patients with diabetes and subclinical hypothyroidism. For the interaction alnalysis, diabetes and subclinical hypothyroidism diagnoses were included in separate, along with a multiplicative interaction term between them.

RESULTS

Point odds ratio estimates for the 4th quartiles of heart rate, and 1st quartiles of all heart rate variability measurements were higher for subjects with combined diabetes and subclinical hypothyroidism than for diabetes only, independently of main sociodemographic and clinical variables (HR: 8.33 vs 2.63; SDNN: 2.59 vs 1.61; RMSSD: 2.37 vs 1.42; LF: 2.83 vs 1.71; HF: 3.06 vs 1.39), but not independently of HbA1c and TSH. Only the interaction term for the association with heart rate, adjusted for sociodemographic and clinical variables, had borderline statistical significance.

CONCLUSION

Diabetes and subclinical hypothyroidism exert a potential joint impact on cardiac autonomic control, showed by additive effects between diabetes and subclinical hypothyroidism, as well as a significant interaction term for the association with heart rate.

Prospective role of thyroid disorders in monitoring COVID-19 pandemic

COVID-19 pandemic has affected more than 200 countries and 1.3 million individuals have deceased within eleven months. Intense research on COVID-19 occurrence and prevalence enable us to understand that comorbidities play a crucial role in spread and severity of SARS-CoV-2 infection. Chronic kidney disease, diabetes, respiratory diseases and hypertension are among the various morbidities that are prevalent in symptomatic COVID-19 patients. However, the effect of altered thyroid-driven disorders cannot be ignored. Since thyroid hormone critically coordinate and regulate the major metabolism and biochemical pathways, this review is on the potential role of prevailing thyroid disorders in SARS-CoV-2 infection. Direct link of thyroid hormone with several disorders such as diabetes, vitamin D deficiency, obesity, kidney and liver disorders etc. suggests that the prevailing thyroid conditions may affect SARS-CoV-2 infection. Further, we discuss the oxidative stress-induced aging is associated with the degree of SARS-CoV-2 infection. Importantly, ACE2 protein which facilitates the host-cell entry of SARS-CoV-2 using the spike protein, are highly expressed in individuals with abnormal level of thyroid hormone. Altogether, we report that the malfunction of thyroid hormone synthesis may aggravate SARS-CoV-2 infection and thus monitoring the thyroid hormone may help in understanding the pathogenesis of COVID-19.

Prevalence of Thyroid Dysfunction in a Chinese Population with Different Glucose Intolerance Status: A Community-Based Cross-Sectional Study

AIM

Impaired glucose metabolism and thyroid dysfunction (TD) are the two most common chronic metabolic disorders. This study aimed to investigate the epidemiological characteristics of TD in different status of glucose tolerance in a community-based Chinese population and to understand the association between TD and glucose metabolism.

METHODS

A community-based population study of metabolic disease was conducted from June 2013 to September 2014 in Beijing, China. Residents aged 26-76 years were selected according to gender and age composition using multi-stage stratified random sampling process. All participants underwent serum thyroid function and thyroid-associated antibody tests. The status of glucose tolerance was determined using 75g-oral glucose tolerance test. Chi-square test was used to compare the differences in prevalence. Multivariate logistic regression analysis was used to determine the impact of insulin resistance (IR) on thyroid function.

RESULTS

By analyzing 3986 participants who were included in the survey, the prevalence of type 2 diabetes (T2DM) and pre-diabetes (pre-DM) was 18.59% and 26.79%, respectively. The prevalence of TD was 8.81%, with overt hyperthyroidism accounting for 0.38%; subclinical hyperthyroidism, 1.86%; overt hypothyroidism, 0.70%; and subclinical hypothyroidism, 5.87%. The prevalence of TD increased with gradually deteriorated glucose tolerance (7.63% in those with normal glucose tolerance, 9.27% in pre-DM, and 11.61% in T2DM) in both men and women. Each unit of higher HOMA-IR was associated with 7% higher likelihood of having subclinical hypothyroidism.

CONCLUSION

The coexisting of TD with T2DM and pre-DM is high in this community-based Chinese population, suggesting a close relationship between TD and glucose metabolism.

Human immunodeficiency virus, diabetes mellitus and thyroid abnormalities: Should we be screening?

BACKGROUND

Diabetes mellitus (DM) and human immunodeficiency virus (HIV) are associated with thyroid abnormalities. Scarce literature exists on the prevalence of thyroid abnormalities in people living with HIV (PLWH) and DM (PLWHD). Guidelines vary regarding thyroid-stimulating hormone (TSH) screening in PLWH and/or DM.

OBJECTIVES

This study describes thyroid abnormalities in PLWHD and HIV-uninfected people living with DM (PLWD).

METHOD

This was a cross-sectional analysis of demographic, clinical and biochemical data including TSH results of first-visit patients to the Edendale Hospital diabetes clinic between January 2016 and December 2017.

RESULTS

A total of 915 patients were enrolled: 165 PLWHD and 750 PLWD. Overall prevalence of thyroid disorders in PLWD was 8.53% (64/750). The occurrence of 'total' thyroid disorders and of 'subclinical-hypothyroidism' (SCH) was higher in PLWHD than PLWD (23.03% vs. 8.53% and 20.61% vs. 4%, p < 0.001; respectively). People living with HIV and diabetes with thyroid disorders had lower CD4 counts than PLWHD without thyroid disorders (376.08 ± 333.30 vs. 509 ± 341.7 cells/mm3; p = 0.004). Subclinical-hypothyroidism was more common in patients on antiretroviral therapy [ART] (27/136 [19.85%] vs. 4/27 [14.81%], p < 0.001). A significant number of PLWHD acquired HIV before the onset of DM (107/165 [64.85%] vs. 58/165 [35.15%], p < 0.001). Patients on ART were more likely to develop DM, OR 2.66 (95% CI 1.11-6.38).

CONCLUSION

Our study showed an increased prevalence of thyroid disorders (especially SCH) in PLWD and a higher prevalence in PLWHD. Young, overweight, female PLWHD were at risk of SCH. People living with HIV and DM on ART demonstrated an increased prevalence of thyroid dysfunction and poor lipaemic control. The introduction of combined communicable-non-communicable disease clinics might provide an integrated patient screening option.

Thyroid hormones in diabetes, cancer, and aging

Thyroid function is central in the control of physiological and pathophysiological processes. Studies in animal models and human research have determined that thyroid hormones modulate cellular processes relevant for aging and for the majority of age‐related diseases. While several studies have associated mild reductions on thyroid hormone function with exceptional longevity in animals and humans, alterations in thyroid hormones are serious medical conditions associated with unhealthy aging and premature death. Moreover, both hyperthyroidism and hypothyroidism have been associated with the development of certain types of diabetes and cancers, indicating a great complexity of the molecular mechanisms controlled by thyroid hormones. In this review, we describe the latest findings in thyroid hormone research in the field of aging, diabetes, and cancer, with a special focus on hepatocellular carcinomas. While aging studies indicate that the direct modulation of thyroid hormones is not a viable strategy to promote healthy aging or longevity and the development of thyromimetics is challenging due to inefficacy and potential toxicity, we argue that interventions based on the use of modulators of thyroid hormone function might provide therapeutic benefit in certain types of diabetes and cancers.

Thyroid dysfunction in patients with type 2 diabetes mellitus and its association with diabetic complications

Background and Aims:

Patients with type 2 diabetes mellitus are more prone to thyroid disorders. Hypothyroidism in them leads to an aggravation of microvascular complications. Diabetic patients with hypothyroidism also are at an increased risk of cardiovascular disease. Screening for thyroid dysfunction in diabetic patients will allow early treatment of hypothyroidism. The aim of this study was to assess the level of thyroid dysfunction in patients with type 2 diabetes mellitus and to identify the association of thyroid dysfunction with diabetic complications.

Methods:

This is a cross-sectional study that was conducted at departments of Medicine & Endocrinology in JIPMER, Pondicherry, between June 2016 and May 2019. 331 patients with type 2 diabetes mellitus attending the out-patient department without any prior history of thyroid disease, chronic liver disease or acute illness were recruited for the study. All subjects were screened for diabetic complications (nephropathy, neuropathy, retinopathy & cardiovascular disease). Thyroid function test was done in all subjects using chemiluminescent immunoassay method.

Results:

Hypothyroidism was seen in 13.9%, while hyperthyroidism was observed in 3.6% of the study subjects. Thyroid dysfunction was more common among females than males. No correlation was seen between thyroid dysfunction and diabetic complications in the study subjects.

Conclusion:

The prevalence of thyroid dysfunction is 17.5% in patients with type 2 diabetes mellitus. Thyroid dysfunction did not have any correlation with diabetic complications.