Correlation between thyroid function, sensitivity to thyroid hormones and metabolic dysfunction-associated fatty liver disease in euthyroid subjects with newly diagnosed type 2 diabetes

Hepatic thyroid hormone receptor-β signalling: Mechanisms and recent advancements in the treatment of metabolic dysfunction-associated steatohepatitis

The pharmacotherapy of metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, the metabolic dysfunction-associated steatohepatitis (MASH), remains a hot topic in research and a largely unmet need in clinical practice. As the first approval of a disease-specific drug, resmetirom, was regarded as a milestone for the management of this common liver disease, this comprehensive and updated review aimed to highlight the importance of the hepatic thyroid hormone (TH) receptor (THR)-β signalling for the treatment of MASH, with a special focus on resmetirom. First, the genomic and non-genomic actions of the liver-directed THR-β mediated mechanisms are summarized. THR-β has a key role in hepatic lipid and carbohydrate metabolism; disruption of THR-β signalling leads to dysmetabolism, thus promoting MASLD and possibly its progression to MASH and cirrhosis. In the clinical setting, this is translated into a significant association between primary hypothyroidism and MASLD, as confirmed by recent meta-analyses. An association between MASLD and subclinical intrahepatic hypothyroidism (i.e. a state of relatively low hepatic triiodothyronine concentrations, with circulating TH concentrations within the normal range) is also emerging and under investigation. In line with this, the favourable results of the phase 3 placebo-controlled MAESTRO trials led to the recent conditional approval of resmetirom by the US FDA for treating adults with MASH and moderate-to-advanced fibrosis. This conditional approval of resmetirom opened a new window to the management of this common and burdensome liver disease, thus bringing the global scientific community in front of new perspectives and challenges.

Relationship of thyroid parameters with chronic inflammation in patients with euthyroid type 2 diabetes

Aims

We evaluated the association of multiple thyroid parameters with the levels interleukin 6 (IL6) and interleukin 8 (IL8) in patients with euthyroid type 2 diabetes (T2D).

Methods

A total of 166 adults with euthyroid T2D were examined. Serum IL6, IL8, triiodothyronine (FT3), free thyroxin (FT4), thyroid-stimulating hormone (TSH), five thyroid sensitivity indexes (FT3/FT4, TSH index [TSHI], thyrotroph T4 resistance index [TT4RI], thyroid feedback quantile-based index by FT3 [TFQIFT3], and TFQIFT4), and biochemical parameters were determined.

Results

The median age was 64 years (IQR: 54.75,70) and the median duration of diabetes was 10 years (IQR: 3,18). Patients with high levels of IL6 (≥2.38 pg/mL) had lower levels of FT3 and TFQIFT3 (P<0.05). Patients with high levels of IL8 (≥18.1 pg/mL) had lower levels of TSH and higher levels of FT4 (P<0.05). IL6 was negatively correlated with FT3 (r=-0.359, P<0.001), TFQIFT3 (r=-0.273, P=0.009), and FT3/FT4 (r=-0.22, P=0.037). IL8 was negatively correlated with TSH (r=-0.256, P=0.01), TSHI (r=-0.226, P=0.033), and TT4RI (r=-0.244, P=0.021). Binary logistic regression analysis with multiple adjusted models showed that a high level of IL6 was negatively associated with FT3 (aOR: 0.529; 95%CI: 0.302, 0.926, P=0.026), and that a high level of IL8 was negatively associated with TSH (aOR: 0.343; 95%CI: 0.155, 0.759; P=0.008) and TT4RI (aOR: 0.398;95%CI: 0.191, 0.831; P=0.014).

Conclusion

Patients with euthyroid T2D who had lower levels of FT3 had significantly higher levels of IL6, and those with lower levels of TSH and TT4RI had significantly higher levels of IL8.

Impaired Sensitivity to Thyroid Hormones is Associated with Central Obesity in Euthyroid Type 2 Diabetes Mellitus Patients with Overweight and Obesity

Background

Thyroid hormone levels are associated with the distribution of body components in humans.

Objective

This study aimed to investigate the associations between thyroid hormone (TH) levels, central sensitivity to THs, and body composition in overweight and obese patients with euthyroid type 2 diabetes mellitus (T2DM).

Methods

This cross-sectional study included 1215 euthyroid T2DM patients (721 men and 494 women) aged 20-80 years. The thyroid hormone sensitivity indices included the thyroid feedback quartile-based index (TFQI), thyrotroph T3 resistance index (TT3RI), thyrotroph T4 resistance index (TT4RI), and thyroid-stimulating hormone index (TSHI). The appendicular fat ratio, trunk fat ratio, android fat ratio, gynoid fat ratio, and appendicular skeletal muscle mass (ASM) were measured via dual-energy X-ray absorptiometry.

Results

The data revealed a greater proportion of subjects with impaired central sensitivity to THs in the obese group. TFQIFT4 and TFQIFT3 levels were positively correlated with the upper limb fat ratio, lower limb fat ratio, gynoid fat ratio, and total fat ratio. TSHI was positively correlated with body mass index (BMI), upper limb fat ratio, lower limb fat ratio, trunk fat ratio, android fat ratio, gynoid fat ratio, total fat ratio, and appendicular skeletal muscle mass index (ASMI) in women. In men, TSHI was only positively correlated with upper limb fat ratio, lower limb fat ratio, and total fat ratio. Logistic regression analysis indicated that TT3RI and TFQIFT3 were independently and positively associated with central obesity and low muscle mass in overweight and obese men. No significant differences were found among the women.

Conclusion

THs central sensitivity is related to the body composition of euthyroid T2DM patients. Specifically, high levels of TT3RI and TFQIFT3 are associated with central obesity and low muscle mass in T2DM men with overweight and obesity.

Expressions of glycemic parameters, lipid profile, and thyroid hormone in patients with type 2 diabetes mellitus and their correlation

OBJECTIVE

This study aimed to investigate the expressions of glycemic parameters, lipid profile, and thyroid hormone in type 2 diabetes mellitus (T2DM) patients and their correlation.

METHODS

Eighty-four patients with T2DM in our hospital were included as the observation group. The T2DM patients were divided into mild group, moderate group, and severe group according to the fasting plasma glucose (FPG) level. Another 84 healthy subjects in the same period of health examination in our hospital were included as the control group. The levels of glycemic parameters, (HbA1c and FPG), lipid profile (TC, TG, LDL-C, and HDL-C) and thyroid hormone (FT3, TSH, and FT4) were measured by automatic biochemical analyzer. The correlation between glycemic parameters, lipid profile, and thyroid hormone was analyzed by Pearson correlation analysis.

RESULTS

The FPG, TC, TG, LDL-C, HbA1c, and TSH levels were significantly elevated, while the HDL-C and FT3 levels were significantly declined in the observation group versus to control group (p < .05). The levels of HbA1c, FPG, TC, LDL-C, and TSH were significantly increased, while the levels of HDL-C and FT3 were decreased in moderate and severe groups, when compared to mild group (p < .05). The levels of HbA1c, FPG, TC, LDL-C and TSH were higher, while the level of FT3 was lower in severe group than those in moderate group (p < .05). Pearson Correlation analysis showed that FT3 level in T2DM patients was positively correlated with FPG, HbAlc, TC, TG, and LDL-C levels (p < .05), but negatively correlated with HDL-C level (p < .05). TSH level was negatively correlated with FPG, HbAlc, TC, TG, and LDL-C levels (p < .05), while positively correlated with HDL-C level.

CONCLUSION

The thyroid hormone levels were of clinical significance in evaluating glycolipid metabolism and severity of T2DM. Clinical detection of glycolipid metabolism and thyroid hormone levels in T2DM patients is of great significance for diagnosis, evaluation, and targeted treatment of the disease.

Relationship between Thyroid Feedback Quantile-based Index and cardiovascular diseases in a population with normal thyroid function: Evidence from the National Health and Nutrition Examination Survey 2007-2012

BACKGROUND

Previous study has demonstrated a link between TFQI, indicating the central sensitivity of thyroid hormones, and conditions like obesity, diabetes, and metabolic syndrome.

HYPOTHESIS

Nevertheless, the potential relationship between TFQI and cardiovascular disease (CVD) in individuals with normal thyroid function has yet to be established.

METHODS

The present research is a retrospective cohort investigation that included a total of 6297 individuals who had normal function of the thyroid and no history of thyroid disorders. These participants were selected from National Health and Nutrition Examination Survey data set, covering the years 2007-2012. The calculation of TFQI was performed depending on FT4 and TSH. Given the complex survey design and sample weights, we used multivariate linear regression models and stratified analysis to evaluate TFQI's correlation with CVD.

RESULTS

Subjects with CVD had greater levels of TFQI than those with no CVD. After adjusting for other covariates, TFQI exhibited a positive association with CVD risk, and the OR was 1.706 (p = .005). In subgroup analyses that were stratified by sex and BMI, it was shown that female individuals who had CVD had greater levels of TFQI in comparison to female participants without CVD (p = .002). Furthermore, elevated levels of TFQI were consistently connected to a raised incidence of CVD in the BMI (>28 kg/m2) group after regulating for different covariates. Furthermore, correlation analysis showed an association between TFQI and metabolic biomarkers.

CONCLUSIONS

The levels of TFQI are strongly connected to the prevalence of CVD, indicating that energy metabolism may be related to the occurrence of CVD.

Investigating the connection among thyroid function, sensitivity to thyroid hormones, and metabolic syndrome in euthyroid children and adolescents affected by type 1 diabetes

OBJECTIVES

A connection between thyroid hormones (THs) and diverse metabolic pathways has been reported. We evaluated thyroid function and tissue sensitivity to THs in children and adolescents with T1D in comparison to euthyroid controls. Additionally, we investigate whether a relationship exists between sensitivity indices and metabolic parameters.

METHODS

A retrospective analysis was conducted on 80 pediatric patients diagnosed with T1D. Clinical parameters, TSH, FT3, FT4, and the presence of MS were documented. Additionally, indices of peripheral sensitivity (FT3/FT4 ratio) and central sensitivity (TSH index, TSHI; TSH T4 resistance index, TT4RI; TSH T3 resistance index, TT3RI) were assessed. Thirty healthy subjects were considered as controls.

RESULTS

The overall prevalence of MS was 7.27 %, with MS identified in 8 out of 80 (10 %) T1D subjects; none of the controls manifested MS (p<0.01). No significant differences were observed in indexes of tissue sensitivity to THs between subjects with or without MS (all p>0.05). Correlations between THs and indexes of THs tissue sensitivity and metabolic parameters in controls and T1D patients were noted.

CONCLUSIONS

This study affirms a heightened prevalence of MS in children with T1D compared to controls and underscores the potential role of THs in maintaining metabolic equilibrium.

Correlation Between Thyroid-Stimulating Hormone (TSH) and Liver Function Test Values in North Karnataka Patients Admitted to a Tertiary Care Hospital

BACKGROUND

Thyroid hormones play a pivotal role in regulating metabolic processes, including liver metabolism. The interplay between thyroid function and liver enzymes is complex, with thyroid dysfunction potentially impacting liver function. The relationship between thyroid-stimulating hormone (TSH) levels and liver function parameters is particularly noteworthy, especially in areas like North Karnataka, India, where dietary and environmental factors may impact thyroid disorders.

AIM AND OBJECTIVES

The principal objective of this research is to explore the association between TSH levels and liver function parameters in individuals from North Karnataka. Secondary objectives include examining the relationship between TSH levels, blood pressure, and the prevalence of comorbidities in the study population.

MATERIALS AND METHODS

This retrospective observational study included 75 patients admitted to a tertiary care hospital in North Karnataka. Patients who had undergone both thyroid function tests and liver function tests were included in the study. Data on blood pressure and comorbidities (like hypothyroidism, hyperthyroidism, hypertension, gastritis, alcohol-related liver disease, anemia, chronic obstructive pulmonary disease (COPD), arthritis, diabetes mellitus, migraine, and uterine disorder) were also collected and analyzed.

RESULTS

The study population comprised 48 females (64%) and 27 males (36%), with a mean age of 46.52 years. Thyroid irregularities were observed in 16 patients (21.4%), with hypothyroidism being the predominant thyroid disorder, accounting for 14 cases (18.7%). The distribution of comorbidities included diabetes mellitus (14 patients; 18.7%), anemia (19 patients; 25.3%), migraine (18 patients; 24%), hypertension (17 patients; 22.7%), gastritis (10 patients; 13.3%), COPD (nine patients; 12%), alcohol-related disorders (four patients; 5.3%), arthritis (three patients; 4%), and uterine disorders (eight patients; 10.6%). It is important to note that some patients presented with more than one comorbidity, which may result in an overlap in the total count of specific conditions reported.

DISCUSSION

The absence of a significant correlation between TSH levels and liver function tests in this study contrasts with some previous research, suggesting that regional factors and dietary habits may play a role in these associations. The high prevalence of thyroid disorders, particularly hypothyroidism, underscores the importance of monitoring thyroid function in this population. The presence of comorbidities such as diabetes mellitus and anemia further complicates the clinical picture and highlights the need for comprehensive healthcare approaches.

CONCLUSION

This study did not find a significant correlation between TSH levels and liver function parameters in patients from North Karnataka. The findings emphasize the need for continued research into the complex interactions between thyroid function and liver metabolism, particularly in regions with unique environmental and dietary influences. Public health initiatives should focus on addressing the high prevalence of thyroid disorders and related comorbidities in this population.

Impaired Sensitivity to Thyroid Hormones is Associated with the Risk of Diabetic Nephropathy in Euthyroid Patients with Type 1 Diabetes Mellitus

Purpose

This study aims to investigate the relationship between thyroid and type 1 diabetic nephropathy (T1DN) in euthyroid populations, focusing on thyroid hormone sensitivity.

Methods

A cross-sectional study was conducted between January 2016 and December 2021, including 357 euthyroid patients with type 1 diabetes mellitus (T1DM). Parameters representing thyroid hormone sensitivity were assessed, including the thyroid feedback quantile-based index (TFQI), parameter thyroid feedback quantile index (PTFQI), thyroid stimulating hormone index (TSHI), thyrotropin thyroxine resistance index (TT4RI), and free triiodothyronine/free thyroxine (FT3/FT4). Logistic regression and restricted cubic spline regression were performed to detect the association between thyroid hormone sensitivity and the risk of T1DN.

Results

The study found a negative correlation between the risk of T1DN and FT3/FT4 in euthyroid T1DM patients (OR 0.71, 95% CI 0.51-0.97, P <0.01). PTFQI (P<0.05), TSHI (P<0.05), and TT4RI (P<0.01) showed an M-shaped nonlinear relationship with the risk of T1DN. Elevated risk of T1DN was associated with PTFQI, TSHI, and TT4RI values outside the range of zero, 2.3-3.88, and 27.56-32.19, respectively.

Conclusion

This study confirms the relationship between impaired thyroid hormone sensitivity and the risk of T1DN in euthyroid patients. It emphasizes the importance of evaluating thyroid hormone sensitivity in T1DM patients, even when their thyroid function appears normal, to promptly prevent the occurrence of T1DN.

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.

Higher Peripheral Thyroid Sensitivity Is Linked to a Lower Risk of Heart Failure After Acute Myocardial Infarction

CONTEXT

It is still not clear how the free triiodothyronine (FT3) to free thyroxine (FT4) ratio affects the prognosis of acute myocardial infarction (AMI), especially the risk of heart failure (HF) subsequent to AMI.

OBJECTIVE

The purpose of this study was to see how peripheral sensitivity to thyroid hormones, as measured by the FT3/FT4 ratio, affected HF and mortality after AMI.

METHODS

Our study was a retrospective cohort study. The primary endpoint was HF after AMI during and after hospitalization. The secondary endpoints were all-cause death and cardiovascular death after hospitalization.

RESULTS

The main sample included 3648 inpatients with AMI with a median age of 61.0 years; 68.9% were male. In the fully adjusted model, compared with patients in the lowest Q1 of the FT3/FT4 ratio, the risk of in-hospital HF in the highest Q4 patients was reduced by 44% (OR 0.56, 95% CI 0.44-0.72, P trend < .001), the risk of out-of-hospital HF was reduced by 37% (HR 0.63, 95% CI 0.48-0.84, P trend < .001), and the risks of all-cause and cardiovascular death were also significantly reduced. The analysis of different subgroups is consistent with the overall results. Furthermore, the sensitivity analysis of the euthyroid sample of 2484 patients was consistent with the main sample. Mediation analysis showed that altered levels of amino-terminal pro-B-type natriuretic peptide were mediators between the FT3/FT4 ratio and all endpoints in our study.

CONCLUSION

The thyroid hormone peripheral sensitivity of the FT3/FT4 ratio is an independent predictor of HF and mortality after AMI.

Association Between Sensitivity to Thyroid Hormones and Metabolic Dysfunction-Associated Fatty Liver Disease in Euthyroid Subjects: A Cross-Sectional Study

Objective

Thyroid hormones (THs) exert instrumental effects in regulating lipids metabolism. Whereas, research investigating the relationship between sensitivity indices to THs and metabolic dysfunction-associated fatty liver disease (MAFLD) have contradicted this. This study was designed to approach the correlation between sensitivity indices to THs and MAFLD in euthyroid subjects.

Methods

An overall sample of 6356 euthyroid participants were enrolled in a Chinese hospital. Free triiodothyronine to free thyroxine ratio (FT3/FT4), thyrotropin triiodothyronine resistance index (TT3RI), thyrotropin thyroxine resistance index (TT4RI), thyroid stimulating hormone index (TSHI) and thyroid feedback quantile-based indices (TFQIFT3 and TFQIFT4) were collected as sensitivity indicators to THs. Participants were split into two groups based on whether they suffered with MAFLD or not. And participants were categorized into quartiles based on sensitivity indicators to THs. The effects of sensitivity indices to THs on MAFLD were analyzed using regression analysis. Bootstrap was performed to assess the mediation effect of triglyceride glucose (TyG) index on the relationship between sensitivity parameters to THs and MAFLD.

Results

The incidence of MAFLD in euthyroid subjects was 34.47%. As FT3/FT4, TT3RI and TFQIFT3 levels rose, so did the MAFLD prevalence. After adjustment for confounders, logistic regression analyses indicated that the high-level FT3/FT4 and TFQIFT3 still remained risk factors for MAFLD. The relevance of FT3/FT4 and MAFLD was stronger among those whose age ≤ 40 years and had non-visceral obesity. And the interrelation between TFQIFT3 and MAFLD was stronger in subjects whose age ≤ 40 years. Mediation analyses suggested that TyG index had a noteworthy indirect impact on the relationship between FT3/FT4, TFQIFT3 and MAFLD.

Conclusion

Increased FT3/FT4 and TFQIFT3 were significantly related to MAFLD prevalence in populations with normal thyroid function. TyG index partly mediated the relevance between FT3/FT4, TFQIFT3 and MAFLD.

Low-Normal Thyroid Function Is Not Associated with Either Non-Alcoholic Fatty Liver Disease or with Metabolic Dysfunction-Associated Fatty Liver Disease

BACKGROUND

The association of low-normal thyroid function (LNTF) with non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated fatty liver disease (MAFLD) is controversial; thus, the aim of this study is to determine this association.

METHODS

NAFLD was evaluated by controlled attenuation parameter of transient elastography. Patients were classified by MAFLD criteria. LNTF was defined as TSH levels of 2.5 to 4.5 mIU/L and were divided into three different cut-off points (>4.5 to 5.0, >3.1, and >2.5 mIU/L). Associations between LNTF, NAFLD, and MAFLD were evaluated by univariate and multivariate logistic regression analyses.

RESULTS

A total of 3697 patients were included; 59% (n = 2179) were male, and median age and body mass index were 48 (43-55) years and 25.9 (23.6-28.5) kg/m², respectively, and 44% (n = 1632) were diagnosed with NAFLD. THS levels of 2.5 and 3.1 showed significant associations with the presence of NAFLD and MAFLD; however, LNTF did not show an independent association with the presence of NAFLD or MAFLD in multivariate analysis. According to different cut-off points, patients with LNTF presented similar risks for NAFLD as the general population.

CONCLUSION

LNTF is not associated with NAFLD or MAFLD. Patients with high LNTF are equally at risk for NAFLD as the general population.