Relationship of thyroid hormone levels and cardiovascular events in patients with type 2 diabetes

The associations of cytokines and gens polymorphisms of β-adrenoceptors in patients with heart failure and some thyroid pathology (literature review and own observations)

OBJECTIVE

Aim: To analyze the role of cytokines in the progression of heart failure (HF) in patients with concomitant pathology of the thyroid gland.

PATIENTS AND METHODS

Materials and Methods: The systematization of literature data on the role of cytokines in the progression of HF in patients with concomitant thyroid pathology (TP) was carried out. The results of our own research were presented.

CONCLUSION

Conclusions: The final chapter in the history of the role of cytokines in the progression of HF has not yet been written. Further studies, including genetic ones, are necessary. The patients with HF have higher levels of TNFβ and IL-6, and a lower concentration of IL-4, compared to the control group. Patients with a fatal outcome of the disease, in contrast to those who survived for two years, have an increased level of TNFβ. In patients with concomitant TP, who had repeated hospitalization, a lower level was registered, compared to that under conditions of a more favorable course of heart failure. Concentrations of cytokines in the blood of patients with HF are associated with gene polymorphisms of the β-adrenoreceptor system: the C-allele of the Gly389A polymorphism of the β1-adrenoceptor gene leads to a decrease in the risk of increasing TNFα; IL-1α increases in the presence of the A-allele of the Ser49Gly polymorphism of this gene. In patients with HF and concomitant thyroid pathology, the risk of IL-6 growth increases in homozygous (C) patients for the Ser275 polymorphism of the β3 subunit of the G-protein.

Serum amyloid A and metabolic disease: evidence for a critical role in chronic inflammatory conditions

Serum amyloid A (SAA) subtypes 1-3 are well-described acute phase reactants that are elevated in acute inflammatory conditions such as infection, tissue injury, and trauma, while SAA4 is constitutively expressed. SAA subtypes also have been implicated as playing roles in chronic metabolic diseases including obesity, diabetes, and cardiovascular disease, and possibly in autoimmune diseases such as systemic lupus erythematosis, rheumatoid arthritis, and inflammatory bowel disease. Distinctions between the expression kinetics of SAA in acute inflammatory responses and chronic disease states suggest the potential for differentiating SAA functions. Although circulating SAA levels can rise up to 1,000-fold during an acute inflammatory event, elevations are more modest (∼5-fold) in chronic metabolic conditions. The majority of acute-phase SAA derives from the liver, while in chronic inflammatory conditions SAA also derives from adipose tissue, the intestine, and elsewhere. In this review, roles for SAA subtypes in chronic metabolic disease states are contrasted to current knowledge about acute phase SAA. Investigations show distinct differences between SAA expression and function in human and animal models of metabolic disease, as well as sexual dimorphism of SAA subtype responses.

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.

Effect of Hyperglycemia-Related Acute Metabolic Disturbance on Thyroid Function Parameters in Adults

Non-thyroidal illness (NTI) is a condition in which the hypothalamic-pituitary-thyroid system and thyroid hormone metabolism are abnormal due to non-thyroidal diseases. Although NTI has been reported to occur in hyperglycemic emergencies in children, there have been few studies in adult cases. In this study, we examined adult patients with hyperglycemia regarding the frequency of NTI and its triggers. Adult diabetic patients who were hospitalized for diabetic ketosis (DK), diabetic ketoacidosis (DKA), or hyperglycemic hyperosmolarity syndrome (HHS) were included in the study. Compared with the DK group, the DKA and HHS groups had higher admission blood glucose, Anion Gap, serum osmolality, creatinine, and urea nitrogen, and lower pH and eGFR. The frequency of NTI in the DKA, HHS, and DK groups was 80%, 70%, and 50%, respectively, and thyroid stimulating hormone (TSH) and free thyroxine 3 (FT3) were significantly improved after treatment for hyperglycemia. Multiple regression analysis showed a significant correlation between the decrease in FT3 level and 3-hydroxybutyrate and albumin. Acute metabolic failure associated with hyperglycemia tends to be associated with a high rate of NTI and low FT3 levels at the start of treatment. The data in this study clearly shows that transient NTI is frequently observed in subjects with acute metabolic disorders such as DKA, HHS and DK. In addition, we should bear in mind that thyroid hormone replacement therapy is not necessary in subjects with NTI due to DKA, HHS and DK, especially when overt symptoms of hypothyroidism are not observed.

Correlations between FTO Gene Polymorphisms and TSH Level in Uyghur Chinese Patients with Type 2 Diabetes

Objective

The aim of this study was to investigate the correlation between polymorphisms in the FTO gene and TSH level in Uyghur patients with type 2 diabetes in the Xinjiang region. Material and Methods. This cohort was made up of 498 Uyghur patients with type 2 diabetes who underwent genotype screening for rs8050136 and rs9939609 using the Sequenom MassARRAY system. The distribution frequencies of the genotypes and alleles at rs8050136 and rs993960 were compared between two patient groups, those with TSH < 2.5 mU/L and those with TSH ≥ 2.5 mU/L group. We further evaluated the relationships between these different genotypes and FT3, FT4, TSH, FPG, and HbA1c expression.

Results

The results suggested the TSH level was 2.281 times higher in rs8050136 CC+CA carriers than in AA genotype (95%CI = 1.024~5.080, P = 0.044) and was 2.417 times higher in rs9939609 TT+TA carriers than in AA genotype (95%CI = 1.257~4.649, P = 0.008) after adjusting for age, sex, and BMI under the recessive model. TSH levels were significantly different between T2DM patients with different FTO genotypes, rs8050136 (P = 0.008) and rs9939609 (P = 0.003), with TSH levels in rs8050136 CC genotype carriers showing a significant increase compared to those in the AA genotype carriers (P = 0.005). Additionally, rs9939609 TT and TA genotype carriers had a significant increase in the TSH level when compared to AA genotype carriers (P = 0.001 and P = 0.031, respectively). The TSH level was also significantly different in these male patients with different genotypes of rs8050136 (P = 0.026) and rs9939609 (P = 0.019). And TSH levels in rs8050136 CC genotype male carriers showing a significant increase compared to those in the AA genotype carriers (P = 0.013) and rs9939609 TT genotype male carriers had a significant increase in TSH level when compared to AA genotype carriers (P = 0.004).

Conclusion

The polymorphisms at rs8050136 and rs9939609 are associated with changes in the TSH level with rs8050136 CC and rs9939609 TT genotypes identified as potential risk factors for increased TSH levels in these male patients.

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.

Jinlida Granules Improve Dysfunction of Hypothalamic-Pituitary-Thyroid Axis in Diabetic Rats Induced by STZ

Objective

We aim to explore the effects and mechanisms of Jinlida granules on the dysfunction of hypothalamic-pituitary-thyroid (HPT) axis in diabetic rats induced by streptozotocin.

Methods

A total of 48 SD rats were randomized into normal control group (NC, n = 6) and diabetic group (n = 42). Rats in diabetic group were randomly divided into diabetes mellitus (DM) control group, low, medium, and high doses of Jinlida group (JL, JM, and JH), medium dose of Jinlida plus Tongxinluo group (JM + T), metformin group (Met), and Saxagliptin group (Sax) (n = 6 in each group). Diabetic rats were obtained by intraperitoneal injection of streptozotocin and sacrificed at 8 weeks to examine the function of HPT axis.

Results

Levels of fasting blood glucose (P < 0.05), pIκB, TNFα (P < 0.05), pNF-κB, and IL-6 (P < 0.01) in liver tissue and TSHR mRNA expression (P < 0.01) in diabetic group were significantly increased, while levels of serum T3 and T4, thyroid hormone receptor (TR) mRNA and Dio1 mRNA in liver tissue, and sodium iodide symporter (NIS) mRNA in thyroid tissue in diabetic group were significantly decreased compared with those in NC group (P < 0.01). Among diabetic groups, level of fasting blood glucose in JH, JM + T and Met group was lower (P < 0.05) compared with DM group. However, levels of serum T3 and T4, TR mRNA in liver tissue, TSHR, and NIS mRNA in thyroid tissue in JH, JM + T, Met, and Sax group were significantly increased (P < 0.01) compared to DM group. In contrast, levels of Dio1 mRNA, pI-κB in Met and JM + T groups, pNF-κB in JH, JM + T, and Met group, and TNFα and IL-6 in JM, JH, JM + T, and Met group were significantly decreased (P < 0.05). HE staining showed reduced thyroid follicular epithelium and follicular area, as well as increased colloid area in DM group, indicating impaired synthesis, reabsorption, and secretory of TH in diabetes, which was significantly improved in JH, JM + T, and Met groups.

Conclusion

HPT axis dysfunction in DM could be significantly improved by Jinlida granules. The mechanism might be associated with the anti-inflammatory effects involving NF-κB pathway. Our findings suggested the potential benefit of Jinlida granules for patients with HPT axis dysfunction and DM, which was to be verified by more experimental and clinical studies.

Association between thyroid hormone parameters and dyslipidemia among type 2 diabetes mellitus patients: Comparative cross-sectional study

BACKGROUND

The relationship between thyroid function and lipid profile has been documented in T2DM and healthy subjects. The aim of the current study was to assess the association between thyroid hormone parameters and dyslipidemia in T2DM and non-diabetic study participants.

METHOD AND MATERIALS

In this comparative cross-sectional study, 214 type 2 diabetic and 214 non-diabetic study participants were enrolled. Clinical and anthropometric data were collected from all study participants. After overnight fasting, 10ml of whole blood samples were drawn for the measurement of serum TSH, free thyroxine (fT4), free triiodothyronine (fT3), serum reactive C-protein levels, as well as for lipid profile test and glucose.

RESULT

The burden of hypothyroidism and subclinical hypothyroidism among T2DM study participants were 73 (17.05%) and 13 (3.04%) respectively. Comparatively, T2DM study participants had significantly higher serum lipid level than non-diabetics. Stratified by TSH, hypothyroid T2DM study participants had increased lipid level than euthyroid subjects. T2DM serum TSH have shown a positive significant correlation with all lipid profile parameters except HDL-C. In the final model (multivariate linear regression), diabetics serum TSH significantly and positively associated with TG and BMI. Diabetic serum fT3 and fT4 negatively associated with body mass index. In addition, diabetics serum fT3 negatively and serum fT4 positively associated with TC and HDL-C respectively.

CONCLUSION

T2DM study subjects had significantly higher lipid level than nondiabetic and We identified that TSH was positively associated with serum TG and BMI among T2DM study participants.

Prevalence of thyroid dysfunction and its impact on cognition in older mexican adults: (SADEM study)

INTRODUCTION

Subclinical thyroid dysfunction is a possible risk factor for cognitive impairment in old age, but results are inconsistent. Aim of the present study was to evaluate the prevalence of thyroid dysfunction among older community-dwelling adults and to see whether thyroid function impacts the cognitive status of the elderly.

METHODS

We included 1750 participants from the Study on Aging and Dementia in Mexico (SADEM). All subjects were evaluated clinically via specific interviews. TSH levels were analyzed by chemiluminescent immunometry assay. We classified participants into five thyroid state groups: (1) normal TSH levels (0.40-4.0 IU/L) were considered euthyroid; (2) Overt hyperthyroidism: TSH <0.3 IU/l and FT4 >23 pmol/l; (3) Overt hypothyroidism: TSH >4.8 IU/l, FT4 <13 pmol/l; (4) Subclinical hyperthyroidism: TSH <0.3 IU/l, FT4: 13-23 pmol/l; (5) Subclinical hypothyroidism: TSH >4.8 IU/l, FT4: 13-23 pmol/l.

RESULTS

The overall estimated prevalence of thyroid dysfunction in Mexican population was 23.7% (95% CI, 22.66-26.77). Of these, 15.4% older adults were classified as subclinical hypothyroidism, 7.2% overt hypothyroidism, 0.5% subclinical hyperthyroidism, and 0.6% overt hyperthyroidism. The association of thyroid dysfunction with cognitive impairment was most evident in overt hypothyroidism OR = 1.261 (1.185-1.343).

CONCLUSIONS

The present study demonstrated a high prevalence of thyroid dysfunction in Mexican elderly people living in the community. A relationship between cognitive impairment and the presence of hypothyroidism was also shown, and to a lesser degree in hyperthyroidism.

Thyroid hormones in extreme longevity

The aim of the present review was to summarize knowledge about thyroid hormones (THs) and longevity. Longevity is a complex multifactorial phenomenon on which specific biological pathways, including hormonal networks involved in the regulation of homeostasis and survival, exert a strong impact. THs are the key responsible for growth, metabolism rate and energy expenditure, and help in maintaining cognition, bone and cardiovascular health. THs production and metabolism are fine tuned, and may help the organism to cope with a variety of environmental challenges. Experimental evidence suggests that hypothyroid state may favor longevity by reducing metabolism rate, oxidative stress and cell senescence. Data from human studies involving healthy subjects and centenarians seem to confirm this view, but THs changes observed in older patients affected by chronic diseases cannot be always interpreted as a protective adaptive mechanism aimed at reducing catabolism and prolonging survival. Medications, selected chronic diseases and multi-morbidity can interfere with thyroid function, and their impact is still to be elucidated.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Abnormalities of Thyroid Hormone Metabolism during Systemic Illness: The Low T3 Syndrome in Different Clinical Settings

Thyroid hormone abnormalities are common in critically ill patients. For over three decades, a mild form of these abnormalities has been described in patients with several diseases under outpatient care. These alterations in thyroid hormone economy are a part of the nonthyroidal illness and keep an important relationship with prognosis in most cases. The main feature of this syndrome is a fall in free triiodothyronine (T3) levels with normal thyrotropin (TSH). Free thyroxin (T4) and reverse T3 levels vary according to the underlying disease. The importance of recognizing this condition in such patients is evident to physicians practicing in a variety of specialties, especially general medicine, to avoid misdiagnosing the much more common primary thyroid dysfunctions and indicating treatments that are often not beneficial. This review focuses on the most common chronic diseases already known to present with alterations in serum thyroid hormone levels. A short review of the common pathophysiology of the nonthyroidal illness is followed by the clinical and laboratorial presentation in each condition. Finally, a clinical case vignette and a brief summary on the evidence about treatment of the nonthyroidal illness and on the future research topics to be addressed are presented.

Relation of thyroid hormone abnormalities with subclinical inflammatory activity in patients with type 1 and type 2 diabetes mellitus

Thyroid hormone (TH) abnormalities are common in patients with diabetes mellitus (DM). These thyroid hormone abnormalities have been associated with inflammatory activity in several conditions but this link remains unclear in DM. We assessed the influence of subclinical inflammation in TH metabolism in euthyroid diabetic patients. Cross-sectional study involving 258 subjects divided in 4 groups: 70 patients with T2DM and 55 patients with T1DM and two control groups of 70 and 63 non-diabetic individuals, respectively. Groups were paired by age, sex, and body mass index (BMI). We evaluated the association between clinical and hormonal variables [thyrotropin, reverse T3 (rT3), total and free thyroxine (T4), and triiodothyronine (T3)] with the inflammation markers C-reactive protein (hs-CRP), serum amyloid A (SAA), and interleukin-6 (IL-6). Serum T3 and free T3 were lower in patients with diabetes (all P < 0.001) compared to the control groups. Interleukin-6 showed positive correlations with rT3 in both groups (P < 0.05). IL-6 was independently associated to FT3/rT3 (B = -0.193; 95% CI -0.31; -0.076; P = 0.002) and FT4/rT3 (B = -0.107; 95% CI -0.207; -0.006; P = 0.039) in the T1DM group. In the T2DM group, SAA (B = 0.18; 95% CI 0.089; 0.271; P < 0.001) and hs-CRP (B = -0.069; 95% CI -0.132; -0.007; P = 0.03) predicted FT3 levels. SAA (B = -0.16; 95% CI -0.26; -0.061; P = 0.002) and IL6 (B = 0.123; 95% CI 0.005; 0.241; P = 0.041) were related to FT4/FT3. In DM, differences in TH levels compared to non-diabetic individuals were related to increased subclinical inflammatory activity and BMI. Altered deiodinase activity was probably involved. These findings were independent of sex, age, BMI, and HbA1c levels.

Free triiodothyronine levels are positively associated with non-alcoholic fatty liver disease in euthyroid middle-aged subjects

BACKGROUND

Studies on the relationship between thyroid function and non-alcoholic fatty liver disease (NAFLD) among euthyroid subjects have produced conflicting results.

OBJECTIVES

The aim of this study was to investigate the association between thyroid function and the presence of NAFLD in a large-sample middle-aged euthyroid subjects.

METHODS

A total of 2576 euthyroid subjects who underwent health check-up were included. NAFLD was diagnosed by hepatic ultrasonography. Conventional risk factors for NAFLD were assessed as well as serum levels of TSH, FT3 and FT4.

RESULTS

Levels of FT3 were significantly higher in NAFLD group (5.12 ± 0.58 versus 4.84 ± 0.58 pmol/L, adjusted p = 0.000) than non-NAFLD group, while levels of TSH and FT4 were comparable between NAFLD and non-NAFLD groups (TSH: 2.13 ± 0.90 versus 2.20 ± 0.93 mIU/L, adjusted p = 0.190; FT4: 16.41 ± 2.04 versus 16.18 ± 2.06 pmol/L, adjusted p = 0.146, respectively). Levels of FT3 were positively correlated with components of metabolic syndrome. Multivariate logistic regression analysis revealed that high level of FT3 was an independent predictor for NAFLD (odds ratio: 1.253, p = 0.040). The relationship between FT4 and NAFLD in women was different according to menopausal status, with negative association in pre-menopausal women (OR: 0.777, 95% CI: 0.617-0.979, p = 0.032) and null association in post-menopausal women (OR: 1.037, 95% CI: 0.841-1.277, p = 0.736).

CONCLUSIONS

Our findings suggested that high levels of FT3 were significantly associated with NAFLD among middle-aged euthyroid subjects independently of known metabolic risk factors. A negative correlation of serum FT4 level with NAFLD was only observed in pre-menopausal women.

Influence of high-normal serum TSH levels on major cardiovascular risk factors and Visceral Adiposity Index in euthyroid type 2 diabetic subjects

Although several observations indicate that serum TSH levels in the high normal range are related to cardiovascular (CVD) risk factors in the general population, similar data are limited in diabetic subjects. The aim of this study was to investigate the potential associations between TSH serum levels within the normal range and major metabolic and non-metabolic CVD risk factors in a cohort of euthyroid type 2 diabetic subjects. Thyroid hormones, TSH levels, anthropometric parameters, lipid profile, glucose control, and blood pressure were measured in 490 euthyroid type 2 diabetic subjects, consecutively attending two outpatient diabetic units in Southern Italy. In all subjects, we also calculated the Visceral Adiposity Index (VAI), an obesity-related index associated with CVD risk. Diabetic women showed higher mean serum TSH levels and lower FT4 concentration than diabetic men, while FT3 levels were comparable in the two genders. Stratifying the study population according to quartiles of TSH levels, subjects in the highest TSH quartile were more likely to be female and younger, with higher values of BMI and waist circumference (P = 0.05 both), higher triglycerides (P = 0.002) and non-HDL cholesterol concentrations (P = 0.01), higher VAI values (P = 0.02), and lower FT4 levels (P = 0.05), when compared to those in the lowest quartile. At multivariate analysis, a younger age, female gender, triglycerides levels, and waist circumference were independently associated with higher TSH levels. In conclusion, in type 2 diabetic subjects with no evidence of thyroid disease, higher TSH concentrations within the normal range were more frequent in women and in younger subjects, and they were associated with visceral obesity and higher triglycerides concentrations, two well-known CVD risk factors.

Impact of thyroid status and age on comprehensive geriatric assessment

This study aimed to evaluate the prevalence of thyroid dysfunction in elderly subjects attending an outpatient clinic at a tertiary hospital and to assess whether subclinical hypothyroidism (SCH) or aging affected activities of daily living (ADLs), instrumental activities of daily living (IADLs), cognitive status, or depressive symptoms. This crosssectional study included 411 patients recruited in the outpatient geriatric setting. 48 subjects reported levothyroxine use and were evaluated separately. After excluding subjects with diseases or drugs which could influence thyroid status, the 284 subjects remaining were classified as having euthyroidism (n = 235, 82.8 %), subclinical hypothyroidism (n = 43, 15.1 %), subclinical hyperthyroidism (n = 4, 1.4 %), or overt hyperthyroidism (n = 2, 0.7 %). ADLs and IADLs were assessed using the Katz Index (ranging from 0 [independence] to 6 [dependence in all activities]) and Health Assessment Questionnaire (ranging from 0 to 3 [severely disabled]), respectively. Cognition was assessed using the mini mental state depressive symptoms that were assessed using the Geriatric depression scale or cornell scale for depression in dementia. SCH did not reduce performance in ADLs or IADLs in elderly subjects as a whole, but was an independent protective factor against dependence in ADLs (OR = 0.196 [0.045-0.853]; p = 0.003) and IADLs (OR = 0.060 [0.010-0.361]; p = 0.002) in subjects aged ≥85 years. Very old subjects with SCH showed better performance in ADLs than did those with euthyroidism (Katz Index: 0.9 ± 1.6 [median: 0.5] vs. 1.7 ± 1.7 [1.0], p = 0.024; HAQ: 1.2 ± 0.8 [0.9] vs. 1.8 ± 1.0 [1.9], p = 0.015). This putative protective effect of SCH was not found in subjects aged <85 years. The number of falls, number of medications used, depressive symptoms, and cognitive impairment did not differ among thyroid status groups, regardless of age. In conclusion, SCH does not have impact functional performance in the elderly population as a whole, but was associated with better functional status in subjects aged ≥85 years.

Thyroid hormone improves the mechanical performance of the post-infarcted diabetic myocardium: a response associated with up-regulation of Akt/mTOR and AMPK activation

OBJECTIVE

Thyroid hormone (TH) is shown to be protective against cardiac and pancreatic injury. Thus, this study explored the potential effects of TH treatment on the functional status of the postinfarcted diabetic myocardium. Diabetic patients have worse prognosis after acute myocardial infarction (AMI).

MATERIALS/METHODS

AMI was induced by left coronary ligation in rats previously treated with 35 mg/kg streptozotocin (STZ), (DM-AMI). TH treatment was initiated at 2 weeks after AMI and continued for 6 weeks (DM-AMI+TH), while sham-operated animals served as control (DM-SHAM).

RESULTS

TH treatment increased cardiac mass, improved wall stress and favorably changed cardiac geometry. TH significantly increased echocardiographic left ventricular ejection fraction (LVEF%): [54.2 (6.5) for DM-AMI+TH vs 37 (2.0) for DM-AMI, p<0.05]. TH treatment resulted in significantly increased insulin and decreased glucose levels in serum. The ratios of phosphorylated (p)-Akt/total Akt and p-mTOR/total mTOR were increased 2.0 fold and 2.7 fold in DM-AMI+TH vs DM-AMI respectively, p<0.05. Furthermore, the ratio of p-AMPK/total AMPK was found to be increased 1.6 fold in DM-AMI+TH vs DM-AMI, p<0.05.

CONCLUSION

TH treatment improved the mechanical performance of the post-infarcted myocardium in rats with STZ-induced diabetes, an effect which was associated with Akt/mTOR and AMPK activation.