Free Triiodothyronine Levels Are Associated with Diabetic Nephropathy in Euthyroid Patients with Type 2 Diabetes

Thyroid hormone treatment counteracts cellular phenotypical remodeling in diabetic organs

Diabetes mellitus and alterations in thyroid hormone (TH) signaling are closely linked. Though the role of TH signaling in cell differentiation and growth is well known, it remains unclear whether its alterations contribute to the pathobiology of diabetic cells. Here, we aim to investigate whether the administration of exogenous T3 can counteract the cellular remodeling that occurs in diabetic cardiomyocytes, podocytes, and pancreatic beta cells. Treating diabetic rats with T3 prevents dedifferentiation, pathological growth, and ultrastructural alterations in podocytes and cardiomyocytes. In vitro, T3 reverses glucose-induced growth in human podocytes and cardiomyocytes, restores cardiomyocyte cytoarchitecture, and reverses pathological alterations in kidney and cardiac organoids. Finally, T3 treatment counteracts glucose-induced transdifferentiation, cell growth, and loss in pancreatic beta cells through TH receptor alpha1 activation. Our studies indicate that TH signaling activation substantially counteracts diabetes-induced pathological remodeling, and provide a potential therapeutic approach for the treatment of diabetes and its complications.

Do not forget the kidney in graves' disease

PURPOSE

To investigate the prevalence of microalbuminuria and factors associated with microalbuminuria in Graves' Disease (GD).

METHODS

This cross-sectional and single-center study included 99 patients with GD and 47 healthy controls (HC). Exclusion criteria such as active infection, uncontrolled diabetes, and chronic kidney disease were applied to the participants. The participants' clinical findings, comorbidities, drug use, laboratory tests, and thyroid antibody levels were recorded. Spot urine samples were collected and stored at - 80 ℃ to analyze the presence of microalbuminuria.

RESULTS

The prevalence of microalbuminuria in patients with GD was 12.1%. The median microalbumin/creatinine ratio in spot urine (UACR) in patients with GD (9.49 mg/g [5.09-18.10]) was higher than in the HC group (7.99 mg/g [3.48-12.88], p = 0.033). UACR was correlated with thyroid-stimulating hormone receptor antibody (TRAb), thyroid-stimulating hormone (TSH), and free triiodothyronine (FT3) levels (p = 0.020, p = 0.006, p = 0.009 respectively). In the regression analysis, only the relationship between TRAb level and UACR remained (p = 0.040).

CONCLUSION

This study demonstrates an increased prevalence of microalbuminuria in patients with GD. There was a significant correlation between microalbuminuria and TRAb level in patients with GD. This relationship suggests that one of the underlying mechanisms of microalbuminuria seen in patients with GD may be autoimmunity.

Systematic Review to Gauge the Effect of Levothyroxine Substitution on Progression of Diabetic Nephropathy in Patients With Hypothyroidism and Type 2 Diabetes Mellitus

Diabetes mellitus (DM) and thyroid dysfunction are two disorders that are closely related. This systematic review aimed to investigate the effect of levothyroxine supplementation on diabetic nephropathy in type 2 diabetic patients with co-existing thyroid dysfunction. We explored medical databases such as PubMed, Medline, Multidisciplinary Digital Publishing Institute (MDPI), and Cochrane Library for relevant medical literature. The papers were screened, and 12 research papers involving 10,371 patients were identified after applying eligibility criteria and quality assessment using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The included papers analyzed the effect of aberrant thyroid profile on kidney disease in diabetic individuals and the role that achieving euthyroid status with levothyroxine supplementation could play in diabetic nephropathy. Reduced free triiodothyronine (FT3) was the most common independent factor associated with diabetic microvascular and macrovascular complications. Levothyroxine (LT4) regimen was more effective than the placebo in lowering urinary albumin excretion rate (UAER), low-density lipoprotein cholesterol, and uric acid and decreasing oxidative stress overall. However, replacement therapy's effect may differ in the short and long terms. Thyroid hormone replacement therapy (THRT) may reduce the risk of diabetic nephropathy and cardiovascular disease (CVD) development in hypothyroid patients, but more randomized trials are needed to confirm the effect of THRT.

Low Circulating Free Triiodothyronine Levels are Associated with the Progression of Diabetic Nephropathy in Patients with Type 2 Diabetes

Background

Diabetic Nephropathy (DN) is one of the most typical causes of end-stage renal disease and thyroid hormone exerts effects on the kidney. There are few reports on the role of thyroid hormone in the progression of DN. We aimed to assess the relationship between thyroid hormone and DN.

Methods

In this cross-sectional study, 400 patients with type 2 diabetes (T2D) (aged between 35 and 70 years) were divided into two groups T2D control and DN group according to albumin creatinine ratio (ACR). Clinical biochemistry parameters were measured using the Rx Daytona chemistry analyzer and thyroid hormone levels (TT4, TT3, TSH, FT4, and FT3) using the Evidence Biochip analyzer. To assess the relationship between thyroid hormone and DN, multiple logistic regression models were developed.

Results

Serum FT4 and FT3 levels were significantly lower in DN compared to T2D controls (p<0.05). Thyroid hormone levels tend to decrease with the progression of DN. In unadjusted and adjusted logistic regression models, FT3 levels were negatively associated with odds of having DN (OR=0.28, CI=0.128-0.616, p=0.002).

Conclusion

The free triiodothyronine level was negatively associated with the progression of DN. Further longitudinal studies are required to assess the cause of thyroid hormone differences.

The analysis of risk factors for diabetic kidney disease progression: a single-centre and cross-sectional experiment in Shanghai

OBJECTIVE

To identify the risk factors for diabetic kidney disease (DKD) development, especially the difference between patients with different courses.

PATIENTS AND METHODS

791 patients were considered to be eligible and were enrolled in the cross-sectional study from Shanghai Tongren Hospital Inpatient Department. 36 variables were initially screened by univariate analysis. The risk factors affecting progression of DKD were determined by logistics regression analysis. Subgroups were grouped according to the course of diabetes disease, and multivariate logistics regression analysis was performed to find out the different risk factors in two subgroups. Finally, the receiver operating characteristics curve is used to verify the result.

RESULTS

The logistic regression model indicated age (OR=1.020, p=0.017, 95% CI 1.004 to 1.040), systolic blood pressure (OR=1.013, p=0.006, 95% CI 1.004 to 1.022), waist circumference (OR=1.021, p=0.015, 95% CI 1.004 to 1.038), white blood cells (WBC, OR=1.185, p=0.001, 95% CI 1.085 to 1.295) and triglycerides (TG, OR=1.110, p=0.047, 95% CI 1.001 to 1.230) were risk factors for DKD, while free triiodothyronine (fT3, OR=0.711, p=0.011, 95% CI 0.547 to 0.926) was a protective factor for DKD in patients with type 2 diabetes mellitus (T2DM). Subgroup analysis revealed that in patients with a short duration of diabetes (<8 years), WBC (OR=1.306, p<0.001, 95% CI 1.157 to 1.475) and TG (OR=1.188, p=0.033, 95% CI 1.014 to 1.393) were risk factors for DKD,fT3 (OR=0.544, p=0.002, 95% CI 0.367 to 0.804) was a protective factor for DKD; whereas for patients with disease course more than 8 years, age (OR=1.026, Pp=0.012, 95%CI=95% CI[ 1.006- to 1.048]) was identified as the only risk factor for DKD and fT3 (OR=0.036, Pp=0.017, 95%CI=95% CI[ 0.439- to 0.922]) was a protective factor for DKD.

CONCLUSION

The focus of attention should especially be on patients with a prolonged course of T2DM, and those with comorbid hypertension and hypertriglyceridaemia waist phenotype. More potential clinical indexes such as thyroid function and inflammatory indicators might be considered as early warning factors for DKD in T2DM. Women should pay attention to controlling inflammation and TGs, and men should strictly control blood pressure. Avoiding abdominal obesity in both men and women will bring great benefits.

The Correlation between Thyroid Hormone Levels and the Kidney Disease Progression Risk in Patients with Type 2 Diabetes

OBJECTIVE

We investigated the relationship between thyroid hormones and the risk of diabetic kidney disease (DKD) progression.

METHODS

A total of 452 patients with type 2 diabetes were included, and a cross-sectional analysis was performed. Urine albumin/creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were used to diagnose persistent albuminuria and stage chronic kidney disease, respectively. The Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline was used to describe the risk of DKD progression (low, moderate, and high or very high risks).

RESULTS

The DKD group had higher levels of thyroid-stimulating hormone (TSH) and lower levels of free triiodothyronine (FT3) and free thyroxine (FT4) than the non-DKD group. The prevalence of thyroid dysfunction in the DKD group was significantly higher than in the non-DKD group, especially the prevalence of subclinical hypothyroidism. FT3 levels decreased gradually with the deterioration of DKD. TSH levels increased with an increasing KDIGO category. FT3 and FT4 levels were negatively correlated with serum creatinine levels and ACR, and positively correlated with eGFR. Contrastingly, TSH was positively correlated with ACR, and negatively correlated with eGFR. After adjustment, an increase in FT3 levels significantly reduced the risk of DKD [odds ratio, OR (95% confidence interval, CI)=0.58 (0.42-0.79)] and DKD progression [ORs (95% CIs)=0.65 (0.45-0.93) for the moderate risk group and 0.50 (0.33-0.74) for the high or very high-risk group, using the low-risk group as a reference]. FT3 levels below 4.30 pmol/L in men and 3.99 pmol/L in women were the cut-off points for an increased risk of DKD progression.

CONCLUSION

Low FT3 level is an independent risk factor for DKD and DKD progression. FT3 ≤4.30 pmol/L in men and ≤3.99 pmol/L in women will greatly increase the risk of kidney disease progression in patients with type 2 diabetes.

Free Triiodothyronine and Free Triiodothyronine to Free Thyroxine Ratio Predict All-Cause Mortality in Patients with Diabetic Foot Ulcers

PURPOSE

Free triiodothyronine (FT3) and FT3/free thyroxine (FT4) ratio have been associated with mortality in various diseases. However, no study to date has identified a link between FT3, FT3/FT4 ratio and all-cause mortality in patients with diabetic foot ulcers (DFUs). This study aimed to investigate this relationship.

METHODS

This retrospective cohort study included 726 patients diagnosed with DFUs in a public hospital from January 2015 to October 2019. Patients were classified by the optimal cut-off values of the FT3 and FT3/FT4 ratio, respectively. The association of FT3 and FT3/FT4 ratio with all-cause mortality was evaluated in a multivariable cox regression model. Directed acyclic graphs were used to assess the minimally sufficient sets of confounding variables.

RESULTS

Log rank tests indicated that patients with low FT3 and FT3/FT4 ratio had lower overall survival rates (all p < 0.001). The adjusted HRs for all-cause mortality were 0.48 (95% CI: 0.32-0.73, P = 0.001) when comparing high versus low FT3 and 0.47 (95% CI: 0.32-0.70, P < 0.001) when comparing high versus low FT3/FT4 ratio. Subgroup analyses showed that these associations existed only in elderly patients (≥65 years) and women, after adjustment. In men, only high FT3/FT4 ratio was associated with low all-cause mortality, after adjustment.

CONCLUSION

Routine assessment of FT3 and FT3/FT4 ratio may be a simple and effective way to identify high-risk patients with DFUs, especially in elderly patients and women.

Association of Thyroid Hormone Levels with Microvascular Complications in Euthyroid Type 2 Diabetes Mellitus Patients

PURPOSE

To examine the prevalence of different microvascular complications and investigate the association between thyroid hormones (THs) and these complications in euthyroid patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 248 T2DM patients were analyzed retrospectively for the study. All patients received a detailed and standard assessment to identify diabetic peripheral neuropathy (DPN), diabetic nephropathy (DN), and diabetic retinopathy (DR). Multivariate logistic regression was carried out to analyze the association between THs and diabetic microvascular complications.

RESULTS

The study found the prevalence of any microangiopathy to be 72.18% (n = 179). At the same time, the prevalence of DPN was 54.84% (n=136), while that of DN was 31.85% (n=79). Likewise, the prevalence of DR was 35.48% (n=88). The odds ratios (ORs) for free triiodothyronine (FT3) developing any microangiopathy, DPN, DN and DR were 0.200, 0.361, 0.310, and 0.588 (P<0.05), respectively. Also, the ORs for free thyroxine (FT4) developing any microangiopathy, DPN, DN and DR were 0.643, 0.800, 0.702 and 0.726 (P<0.05), respectively. Lastly, the ORs for thyroid-stimulating hormone (TSH) developing DPN was 1.57 (95% CI: 1.148-2.137, P=0.005).

CONCLUSION

The study concludes that serum FT3 and FT4 levels are negatively associated with any microangiopathy, DPN, DN and DR in euthyroid patients with T2DM, independent of traditional risk factors. However, the TSH levels are positively associated with DPN. Future larger sample-size studies are needed to confirm the relationship between thyroid hormone levels and microvascular complications in euthyroid patients with T2DM.

Elevated Serum Levels of Carbohydrate Antigen 72-4 in Diabetic Kidney Disease

The aim of this study was to determine whether carbohydrate antigen 72-4 (CA72-4) is elevated in diabetic kidney disease (DKD), and examine the association between urinary albumin-to-creatinine ratio (UACR) and CA72-4 in patients with type 2 diabetes mellitus (T2DM). Non-dialysis patients with T2DM (n=296) and 90 healthy controls were recruited in this study. CA72-4 level was measured by electrochemiluminescence immunoassay. DKD was defined as UACR≥ 30 mg/g in the absence of a urinary infection or other renal diseases. We found that patients with DKD had significantly higher serum CA72-4 levels compared to those with normoalbuminuria and healthy controls. Positive rates of CA72-4 increased gradually and markedly from normoalbuminuria to microalbuminuria and to macroalbuminuria in diabetic patients (7.5, 11.2, and 17.4%, respectively; P for trend< 0.05). CA72-4 also showed a positive correlation with UACR (r=0.288, P< 0.01). Logistic regression analysis revealed the association of increased UACR with an increased odds ratio of elevation of CA72-4 levels (P for trend< 0.05) after multivariable adjustment. In conclusion, serum levels of CA72-4 increase abnormally with the increase in urinary albumin excretion, which affects the specificity of diagnosis of malignancies. An appropriate interpretation of CA72-4 is essential to prevent unnecessary and even hazardous diagnostic procedures in patients with T2DM.

Associations between the thyroid panel and serum protein concentrations across pregnancy

Establishing any characteristic associations between the serum parameters of thyroid function and serum proteins in pregnancy may aid in elucidating the role of the thyroid gland in the regulation of pregnancy-specific metabolic processes and in selecting candidate biomarkers for use in their clinical assessment. Concentrations of thyroid stimulating hormone (TSH), free tri-iodothyronine (fT3) and free thyroxine (fT4), six electrophoretically separated protein fractions (albumin, alpha-1-, alpha2-, beta-1-, beta-2- and gamma-globulins), representative proteins—albumin (ALB), transferrin (TRF), alpha-2-macroglobulin (AMG) and ceruloplasmin (CER) were measured in 136 serum samples from 65 women in their consecutive trimesters of pregnancy. The concentrations of TSH, fT4 and fT3 were significantly correlated (p < 0.05) with the concentrations of the albumin, alpha-2- and beta-1 globulin fractions. Significant correlations (p < 0.05) which were positive between fT4 and ALB and negative between fT4 and TRF were established throughout pregnancy. Significant negative correlations (p < 0.05) were demonstrated for fT3 with alpha-2-globulin, AMG and CER. Changes in the serum concentrations of thyroid hormones seen between the trimesters were found to correlate with the concentrations of high-abundance serum proteins. Opposite directions of correlations between fT4 and ALB and fT4 and TRF observed throughout pregnancy may indicate the shared biological role of these parameters in maintaining maternal homeostasis and they suggest their potential use in the clinic as a simple biomarker panel. A negative correlation of fT3 with CER in the second trimester possibly reflects their involvement in the active regulation of metabolic processes.

Is there a relationship between the prevalence of autoimmune thyroid disease and diabetic kidney disease?

Autoimmune thyroid disease (AITD) is more common among diabetes mellitus (DM) patients and may impact its microvascular complications. The present study aimed to assess the relationship between AITD and the prevalence of diabetic kidney disease (DKD) in patients with diabetes mellitus type 1 (DM1). Anthropometric parameters, parameters of metabolic control of DM, thyreometabolic status, and the UACR were assessed. DKD was diagnosed if patients' UACR level was ≥30 mg/g or eGFR level was <60 mL/min. This study involved 144 patients with DM1 aged 36.2 ± 11.7 years: 49 men and 95 women. Significant differences in creatinine, eGFR, and UACR levels were found in patients with DKD. fT3 concentration was significantly lower among DKD patients. A significantly higher probability of DKD was found in DM1 patients with lower fT3 levels. Patients with DM1 and AITD had significantly lower creatinine levels than the control group. However, the study did not show any significant relationship between AITD and the occurrence of DKD in patients with DM1. Significantly lower fT3 concentrations in DKD patients may be caused by metabolic disorders in the course of DKD and require further cohort studies in a larger population of patients with DM1 and AITD.

Associations of Thyroid Hormone Levels and Macrovascular Complications in Euthyroid Type 2 Diabetic Patients

PURPOSE

The purpose of this study is to evaluate whether thyroid hormone in euthyroid patients with type 2 diabetes mellitus (T2DM) is associated with macrovascular complications.

PATIENTS AND METHODS

The authors examined 311 patients enrolled from February 2019 to December 2019 in Tianjin Medical University Chu Hsien-I Memorial Hospital. A medical record review enabled the collection of demographic and anthropometric information. We classified the patients into two groups based on the echocardiography and vascular ultrasonography results, namely, non-macrovascular complications (n=131) group and macrovascular complications (n=180) group. Odds ratios (OR) and 95% confidence intervals (CI) were calculated, adjusting for potential confounders, the prevalence of macrovascular complications was determined using multivariate logistic regression.

RESULTS

A significant association was observed for diabetic macrovascular complications with normal free triiodothyronine (FT3) (OR=0.534, 95% CI 0.358-0.796, p = 0.002) and free thyroxine (FT4) (OR= 0.844, 95% CI 0.760-0.937, p = 0.001). Nevertheless, there was no evidence of any association between thyroid-stimulating hormone (TSH) and the development of diabetic macrovascular complications. When stratified by the body mass index (BMI), a similar relationship existed with the overall results. The positive association remained in restricted analyses involving only patients with HbA1c abnormalities.

CONCLUSION

Overweight or obese T2DM patients are at high risk due to the implicit association between low but clinically normal thyroid hormone levels and elevated risk of macrovascular complications. However, there were no statistically significant associations between TSH and diabetic macrovascular complications.

Diabetic Nephropathy: Novel Molecular Mechanisms and Therapeutic Targets

Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes mellitus and the leading cause of end-stage kidney disease. The standard treatments for diabetic patients are glucose and blood pressure control, lipid lowering, and renin-angiotensin system blockade; however, these therapeutic approaches can provide only partial renoprotection if started late in the course of the disease. One major limitation in developing efficient therapies for DN is the complex pathobiology of the diabetic kidney, which undergoes a set of profound structural, metabolic and functional changes. Despite these difficulties, experimental models of diabetes have revealed promising therapeutic targets by identifying pathways that modulate key functions of podocytes and glomerular endothelial cells. In this review we will describe recent advances in the field, analyze key molecular pathways that contribute to the pathogenesis of the disease, and discuss how they could be modulated to prevent or reverse DN.

Iodine nutrition status and its association with microvascular complications in urban dwellers with type 2 diabetes

Background

The principal function of iodine acts on thyroid function, but in recent years, the role of iodine deficiency in metabolism has also been gradually revealed. We aimed to investigate the current status of iodized salt consumption and urinary iodine concentration (UIC) in an urban Chinese population with type 2 diabetes, and to further explore whether UIC was associated with diabetic microvascular complications.

Methods

Four thousand five hundred fifty-nine subjects with diabetes from 7 communities in downtown Shanghai were enrolled in the cross-sectional Metal Study in 2018. UIC was detected using an inductively coupled plasma-mass spectrometer. Diabetic kidney disease (DKD) was defined as urinary albumin-to-creatinine ratio (UACR) > 30 mg/g or estimated glomerular filtration rate < 60 mL/min/1.73 m². Diabetic retinopathy (DR) was evaluated by high-quality fundus photographs and was remotely read by ophthalmologist.

Results

The median UIC of subjects with diabetes was 115.4 μg/L (78.9–170.8) in downtown Shanghai. Among all the subjects, 52.7% consumed non-iodized salt and 40.4% were iodine deficient. Iodine deficiency (UIC < 100 μg/L) was associated with an increased odds of DKD (OR 1.17; 95%CI 1.01–1.37) after adjustment for age, sex, education, current smokers, BMI, HbA1c, duration of diabetes, dyslipidemia, thyroid-stimulating hormone and free thyroxine. No association was observed between UIC and DR after multivariable adjustment.

Conclusions

A concerning number of subjects with diabetes consumed non-iodized salt and suffered from iodine deficiency in coastal regions of China. Low UIC might be a risk factor for DKD, which should be further confirmed by longitudinal prospective studies.

Association between Normal Thyroid Hormones and Diabetic Retinopathy in Patients with Type 2 Diabetes

The relationship between normal thyroid function and type 2 diabetes mellitus (T2DM) has been a particular focus for concern. The present study determined the relationship between thyroid hormone levels and the prevalence of diabetic retinopathy (DR) in T2DM patients. A cross-sectional study (n = 633) was performed in Xi'an, Shaanxi Province, China. Subjects were evaluated for anthropometric measurements, thyroid function, and diabetic retinopathy. Logistic regression models were used to assess the relationships between thyroid hormones and DR. Of 633 patients, 243 (38.4%) patients suffered from DR. The prevalence of DR showed a significantly decreasing trend across the quartiles based on free triiodothyronine (FT3) (FT3 quartile 1 group [FT3-Q1] <4.35 pmol/L, FT3 quartile 2 group [FT3-Q2] 4.35–4.70 pmol/L, FT3 quartile 3 group [FT3-Q3] 4.70–5.08 pmol/L, and FT3 quartile 4 group [FT3-Q4] ≥5.08 pmol/L) (56.7%, 42.5%, 33.1%, 23.8%, P < 0.001). In comparison with all participants categorized in FT3-Q1, the multivariable adjusted odds ratios (95% confidence interval) of DR in FT3-Q2, FT3-Q3, and FT3-Q4 were 0.587 (0.340–1.012), 0.458 (0.258–0.813), and 0.368 (0.201–0.673), (P = 0.055, P = 0.008, P = 0.001), respectively. FT3 levels within the normal range are negatively associated with DR in euthyroid patients with type 2 diabetes. Further studies should be aimed at clarifying the relationship between thyroid hormones and T2DM.

Association between Free Thyroxine Levels and Diabetic Retinopathy in Euthyroid Patients with Type 2 Diabetes Mellitus

Background: This study aimed to evaluate the association between thyroid parameters and diabetic retinopathy (DR) in euthyroid patients with type 2 diabetes mellitus (T2DM).Materials and Methods: In this cross-sectional study, a total of 911 euthyroid patients with T2DM (539 men and 372 women; mean age, 60.81 ± 12.93 years) were enrolled. Clinical factors were assessed and free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels were measured. DR was diagnosed using fundus fluorescein angiography.Results: Compared with patients without DR (n = 718), patients with DR (n = 193) exhibited lower FT3 (4.40 ± 0.58 vs. 4.50 ± 0.51 pmol/L; P = .019) and FT4 (14.86 ± 2.09 vs. 15.91 ± 2.18 pmol/L; P < .001) and higher TSH (1.86 [1.22, 2.66] vs. 1.58 [1.14, 2.34] µIU/mL; P = .015) levels. After adjustment for potential DR risk factors, patients in the highest tertile of plasma FT4 levels had a 0.332-fold likelihood of developing DR compared with those in the lowest tertile of plasma FT4 levels (P_trend < 0.001). The prevalence of DR showed a significantly decreasing trend across the three tertiles based on FT4 levels (31.35%, 19.08% and 13.16%; P_trend < 0.001). Similar results were obtained for the presence of proliferative DR.Conclusion: These findings suggest that low-normal FT4 levels are associated with the prevalence of DR in euthyroid patients with T2DM.

Thyroid Parameters and Kidney Disorder in Type 2 Diabetes: Results from the METAL Study

OBJECTIVE

Diabetic kidney disease is one of the most common microvascular complications of diabetes mellitus. We aimed to analyze the association of thyroid parameters with kidney disorders, especially in euthyroid participants.

METHODS

The data were obtained from a cross-sectional study, the METAL study. Thyroid parameters, including thyroid-stimulating hormone (TSH), free triiodothyronine (FT₃), free thyroxine (FT₄), triiodothyronine (T₃), thyroxin (T₄), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb), of 4136 participants with type 2 diabetes were measured. Two structure parameters of thyroid homeostasis, including the sum activity of step-up deiodinases (SPINA-G_D) and thyroid secretory capacity (SPINA-G_T), and two pituitary thyrotropic function indices, including Jostel's TSH index (TSHI) and the thyrotroph thyroid hormone resistance index (TTSI), were also calculated. Kidney disorders were described according to the presence of reduced estimated glomerular filtration rate (eGFR) and/or higher urinary albumin to creatinine ratio (UACR).

RESULTS

The prevalence of kidney disorders increased with decreasing FT₃ or T₃ and increasing FT₄ or T₄ quartile levels (all P < 0.05). After full adjustment, linear regression showed that UACR levels were negatively associated with FT₃ and T₃ (P < 0.001). In addition, eGFR was positively associated with FT₃ and T₃ and was negatively associated with TSH and FT₄ levels and TgAb positivity (all P < 0.05). By using binary logistic regression, higher TSH and FT₄ and lower FT₃ and T₃ were associated with kidney disorders (all P < 0.05). Similar results were seen in sensitivity analyses, which were performed in 3035 euthyroid diabetic participants; however, TSH was no longer related to them. The area under the receiver operating characteristic curve (AUROC) of lower FT₃ for existing kidney disorder was greater than that for any other thyroid hormones (all P < 0.001). The cutoff value of FT₃ for reduced eGFR was 4.39 pmol/L. Regarding thyroid homeostasis parameters, SPINA-G_D was negatively associated with three statuses of kidney disorders, and TSHI and TTSI were positively associated with reduced eGFR (all P < 0.05).

CONCLUSIONS

Among patients with type 2 diabetes, elevated TSH and FT₄ (or T₄), lower FT₃ (or T₃), TgAb positivity, lower SPINA-G_D, and higher TSHI and TTSI were associated with kidney disorders. The lower FT₃, even within the normal range (<4.38 pmol/L), may be the factor most related to reduced eGFR compared with other thyroid hormones in diabetic patients.

Alteration of thyroid hormone signaling triggers the diabetes-induced pathological growth, remodeling, and dedifferentiation of podocytes

Thyroid hormone (TH) signaling is a universal regulator of metabolism, growth, and development. Here, we show that TH-TH receptor (TH-TR) axis alterations are critically involved in diabetic nephropathy-associated (DN-associated) podocyte pathology, and we identify TRα1 as a key regulator of the pathogenesis of DN. In ZSF1 diabetic rats, T3 levels progressively decreased during DN, and this was inversely correlated with metabolic and renal disease worsening. These phenomena were associated with the reexpression of the fetal isoform TRα1 in podocytes and parietal cells of both rats and patients with DN and with the increased glomerular expression of the TH-inactivating enzyme deiodinase 3 (DIO3). In diabetic rats, TRα1-positive cells also reexpressed several fetal mesenchymal and damage-related podocyte markers, while glomerular and podocyte hypertrophy was evident. In vitro, exposing human podocytes to diabetes milieu typical components markedly increased TRα1 and DIO3 expression and induced cytoskeleton rearrangements, adult podocyte marker downregulation and fetal kidney marker upregulation, the maladaptive cell cycle induction/arrest, and TRα1-ERK1/2-mediated hypertrophy. Strikingly, T3 treatment reduced TRα1 and DIO3 expression and completely reversed all these alterations. Our data show that diabetic stress induces the TH-TRα1 axis to adopt a fetal ligand/receptor relationship pattern that triggers the recapitulation of the fetal podocyte phenotype and subsequent pathological alterations.

Thyroid Hormone Signalling: From the Dawn of Life to the Bedside

Thyroid hormone (TH) signalling is a key modulator of fundamental biological processes that has been evolutionarily conserved in both vertebrate and invertebrate species. TH may have initially emerged as a nutrient signal to convey environmental information to organisms to induce morpho-anatomical changes that could maximise the exploitation of environmental resources, and eventually integrated into the machinery of gene regulation and energy production to become a key regulator of development and metabolism. As such, TH signalling is particularly sensitive to environmental stimuli, and its alterations result in fundamental changes in homeostasis and physiology. Stressful stimuli of various origins lead to changes in the TH-TH receptor (TR) axis in different adult mammalian organs that are associated with phenotypical changes in terminally differentiated cells, the reactivation of foetal development programmes, structural remodelling and pathological growth. Here, we discuss the evolution of TH signalling, review evolutionarily conserved functions of THs in essential biological processes, such as metamorphosis and perinatal development, and analyse the role of TH signalling in the phenotypical and morphological changes that occur after injury, repair and regeneration in adult mammalian organs. Finally, we examine the potential of TH treatment as a therapeutic strategy for improving organ structure and functions following injury.

Thyroid Function in Patients with Type 2 Diabetes Mellitus and Diabetic Nephropathy: A Single Center Study

Background

Diabetes mellitus is a common metabolic disease and the prevalence is increasing rapidly. Thyroid disorders including subclinical hypothyroidism (SCH) and low triiodothyronine (T3) syndrome are frequently observed in diabetic patients. We conducted a study to explore thyroid function in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN).

Methods

We included 103 healthy volunteers, 100 T2DM patients without DN, and 139 with DN. Physical examinations including body mass index and blood pressure and laboratory measurements including renal function, thyroid function, and glycosylated hemoglobin were conducted.

Results

Patients with DN had higher thyroid stimulating hormone (TSH) levels and lower free T3 (FT3) levels than those without DN (p < 0.01). The prevalence of SCH and low FT3 syndrome in patients with DN was 10.8% and 20.9%, respectively, higher than that of controls and patients without DN (p < 0.05). Through Pearson correlation or Spearman rank correlation analysis, in patients with DN, there were positive correlations in TSH with serum creatinine (r = 0.363, p = 0.013) and urinary albumin-to-creatinine ratio (r = 0.337, p = 0.004), and in FT3 with estimated glomerular filtration rate (eGFR) with statistical significance (r = 0.560, p < 0.001).

Conclusions

High level of TSH and low level of FT3 were observed in T2DM patients with DN. Routine monitoring of thyroid function in patients with DN is necessary, and management of thyroid dysfunction may be a potential therapeutic strategy of DN.

Relationship between serum thyrotropin and urine albumin excretion in euthyroid subjects with diabetes

BACKGROUND

Microalbuminuria represents vascular and endothelial dysfunction. Thyroid hormones can influence urine albumin excretion as it exerts crucial effects on the kidney and on the vascular system. This study explores the relationship between serum thyrotropin and urine albumin excretion in euthyroid patients with diabetes.

METHODS

A total of 433 patients with type 1 or 2 diabetes were included in this retrospective cross-sectional study. Data included anthropometric measurements and biochemical parameters from diabetes clinic. Males with urine albumin creatinine ratio >2.5 and female's >3.5 mg/mmoL were considered to have microalbuminuria.

RESULTS

34.9% of the patients had microalbuminuria. Prevalence of microalbuminuria increased according to TSH quartiles (26.9, 34.6, 38.5 and 44.9%, P for trend = 0.02). In a fully adjusted logistic regression model, higher TSH concentrations were associated with high prevalence of microalbuminuria (adjusted odds ratio 2.06 [95% CI: 1.14-3.72]; P = 0.02), while comparing the highest with the lowest quartile of TSH. Multiple linear regression analysis showed an independent association between serum TSH and urine albumin creatinine ratio (β = 0.007, t = 2.03 and P = 0.04). The risk of having microalbuminuria was higher with rise in TSH concentration in patients with younger age (<65 years), raised body mass index (≥25 kg/m²), hypertension, type 2 diabetes and hyperlipidaemia and age was the most important determinant ( P for interaction = 0.02).

CONCLUSION

Serum TSH even in the euthyroid range was positively associated with microalbuminuria in euthyroid patients with diabetes independent of traditional risk factors. This relationship was strongest in patients with components of the metabolic syndrome.

Thyroid stimulating hormone and free triiodothyronine are valuable predictors for diabetic nephropathy in patient with type 2 diabetes mellitus

Background

Diabetes seriously threatens human health, and diabetic nephropathy (DN) is one of the serious diabetic complications. Therefore, it is valuable to predict the occurrence of DN early. This study aims to evaluate the predicting significance of thyroid hormones for DN.

Methods

A total of 301 type 2 diabetes mellitus (T2DM) patients were enrolled. Thyroid hormones before treatment were measured, and the risk factors and their predicting significance for T2DM and DN were assessed.

Results

The results indicated that there was no statistical difference in any investigated variable between controls and patients without complications (P>0.05). However, patients with DN exhibited lower levels of triiodothyronine (T3) and free triiodothyronine (FT3), but higher levels of thyroid stimulating hormone (TSH) than T2DM patients without complications (P<0.001). Multivariate analysis did not demonstrate any thyroid hormone as the independent risk factor for T2DM without complications, but revealed increased TSH and decreased T3 and FT3 as the independent risk factors for patients with DN [odds ratio (OR): 2.087, 95% CI: 1.525-3.303; 1.335, 95% CI: 1.101-1.621; 7.414, 95% CI: 4.319-13.986; P<0.001, respectively]. The area under receiver operating characteristic (ROC) curve of TSH, FT3 and T3 was 0.850 (95% CI: 0.776-0.923), 0.824 (95% CI: 0.751-0.897), and 0.620 (95% CI: 0.515-0.725) for DN prediction. Based on their cutoff values of 1.85 mIU/L, 2.31 ng/L, and 0.61 µg/L, the sensitivity was 82%, 78%, and 64%, and the specificity was 77%, 79%, and 85%, respectively.

Conclusions

Our findings suggest that TSH and FT3 are useful predictors for DN in patients with T2DM.

Assessment of the Relationship between Carotid Intima-Media Thickening and Early-Stage Diabetic Kidney Disease Coupled with Helicobacter pylori Infection

Objective

This study aimed to explore the associations between carotid intima-media thickness (CIMT) and early-stage diabetic kidney disease (DKD) coupled with Helicobacter pylori (H. pylori) infection in type 2 diabetic patients.

Methods

A cross-sectional study including 180 type 2 diabetic participants was conducted to explore the associations between CIMT and early-stage DKD coupled with H. pylori infection, and a stepwise multivariate regression analysis evaluated the correlations of CIMT with clinical and serologic parameters.

Results

The type 2 diabetic patients with early-stage DKD coupled with H. pylori infections had the highest CIMT values. Apolipoprotein B (ApoB), urine albumin/creatinine ratio (UACR), and interleukin-6 (IL-6) were independent predictors of CIMT.

Conclusions

Early-stage DKD coupled with H. pylori infection may synergistically lead to significant CIMT thickening in type 2 diabetic patients. Additionally, ApoB, UACR, and IL-6 levels were important independent risk factors for increased CIMT.

Diabetes classification model based on boosting algorithms

BACKGROUND

Diabetes mellitus is a common and complicated chronic lifelong disease. Hence, it is of high clinical significance to find the most relevant clinical indexes and to perform efficient computer-aided pre-diagnoses and diagnoses.

RESULTS

Non-parametric statistical testing is performed on hundreds of medical measurement index results between diabetic and non-diabetic populations. Two common boosting algorithms, Adaboost.M1 and LogitBoost, are selected to establish a machine model for diabetes diagnosis based on these clinical test data, involving a total of 35,669 individuals. The machine classification models built by these two algorithms have very good classification ability. Here, the LogitBoost classification model is slightly better than the Adaboost.M1 classification model. The overall accuracy of the LogitBoost classification model reached 95.30% when using 10-fold cross validation. The true positive, true negative, false positive, and false negative rates of the binary classification model were 0.921, 0.969, 0.031, and 0.079, respectively, and the area under the receiver operating characteristic curve reached 0.99.

CONCLUSIONS

The boosting algorithms show excellent performance for the diabetes classification models based on clinical medical data. The coefficient matrix of the original data is a sparse matrix, because some of the test results were missing, including some that were directly related to disease diagnosis. Therefore, the model is robust and has a degree of pre-diagnosis function. In the process of selecting the preferred test items, the most statistically significant discriminating factors between the diabetic and general populations were obtained and can be used as reference risk factors for diabetes mellitus.

Association between Thyroid Hormone Levels and Diabetic Kidney Disease in Euthyroid Patients with Type 2 Diabetes

The association between normal thyroid function and diabetic kidney disease (DKD) has gained increasing attention. The present study evaluated the relationship between normal thyroid hormone levels and DKD in type 2 diabetes mellitus (T2DM) patients. A total of 862 type 2 diabetes patients were enrolled in this cross-sectional study in Xi^’an, Shaanxi Province, China. The subjects were evaluated for anthropometric measurements, thyroid function and DKD. Of 862 patients, 246 (28.5%) suffered from DKD, and the prevalence of DKD did not differ between men and women. The prevalence of DKD showed a significantly decreasing trend across the quartiles based on free triiodothyronine (FT3) levels (41.1%, 30.6%, 23.8%, and 18.9%, P < 0.001). In comparison with all participants categorized in the first FT3 quartile group (FT3-Q1) (<4.380), the adjusted odds ratio of DKD in the second FT3 quartile group (FT3-Q2), the third FT3 quartile group (FT3-Q3), and the fourth FT3 quartile group (FT3-Q4) were 0.655(95%CI: 0.406–1.057), 0.493(95%CI: 0.299–0.813), 0.406(0.237–0.697) (P < 0.05). Also, similar results were observed in men. Conversely, none of the FT3 groups was associated with DKD in women. The present study showed that FT3 within normal range was negatively correlated with DKD in T2DM patients.

Subclinical hypothyroidism and diabetic nephropathy in Iranian patients with type 2 diabetes

PURPOSE

Association of subclinical hypothyroidism with type 2 diabetes and its complications has been previously documented. These reports were, however, inconclusive and mainly gathered from Chinese and East Asian populations. In this study, we aimed to determine the prevalence of subclinical hypothyroidism and its relationship with diabetic nephropathy in Iranian individuals with type 2 diabetes, drawn from a white Middle Eastern population with an increasing prevalence of diabetes.

METHODS

In this cross-sectional study, 255 Iranian participants with type 2 diabetes and without history of thyroid disorders were included. Patients with TSH > 4.2 mIU/L and normal T4 were classified as having subclinical hypothyroidism. Diabetic nephropathy was diagnosed based on abnormal 24-h urinary albumin or protein measurements (24-h urinary albumin ≥30 mg/day or 24-h urinary protein ≥150 mg/day). Multivariate logistic regression was employed to obtain the OR for the relationship between subclinical hypothyroidism and diabetic nephropathy.

RESULTS

We found that subclinical hypothyroidism and diabetic nephropathy were as prevalent as 18.1 and 41.2 %, respectively, among the participants. We also found that subclinical hypothyroidism was independently associated with higher rates of diabetic nephropathy, after multivariable adjustment (OR [95 % CI] 3.23 [1.42-7.37], p = 0.005).

CONCLUSIONS

We found that the prevalence of subclinical hypothyroidism in Iranian diabetic population was among the highest rates reported to date. Our data supported the independent association of subclinical hypothyroidism with diabetic nephropathy, calling for further investigations to evaluate their longitudinal associations.

Elevated Squamous Cell Carcinoma Antigen, Cytokeratin 19 Fragment, and Carcinoembryonic Antigen Levels in Diabetic Nephropathy

OBJECTIVE

We aimed to explore whether squamous cell carcinoma antigen (SCC), cytokeratin 19 fragment (Cyfra21-1), neuron-specific enolase (NSE), and carcinoembryonic antigen (CEA) are elevated in diabetic nephropathy (DN) and the association between urinary albumin-to-creatinine ratio (UACR) and tumor markers in diabetic patients.

METHODS

Nondialysis patients with diabetes (n = 261) and 90 healthy controls were enrolled. DN was defined as an UACR ≥ 30 mg/g in the absence of a urinary tract infection or other renal abnormalities.

RESULTS

Patients with DN had significantly higher serum SCC, Cyfra21-1, and CEA levels than those with normoalbuminuria and healthy controls. The rates of positive SCC, Cyfra21-1, and CEA significantly increased with increasing urinary albumin excretion (all P for trend < 0.001). In contrast, NSE was not affected by DN. SCC, Cyfra21-1, and CEA were significantly and positively correlated with UACR. In logistic regression, after multivariable adjustment, increased UACR was associated with increased odds ratio of elevated tumor marker levels (all P for trend < 0.05).

CONCLUSIONS

Serum levels of SCC, Cyfra21-1, and CEA are markedly increased with increasing urinary albumin excretion, which affects the specificity for diagnosis for lung cancer. Appropriate interpretation of tumor markers in diabetic patients is mandatory to avoid unnecessary and even hazardous biopsies.