CASE FINDING FOR HYPOTHYROIDISM SHOULD INCLUDE TYPE 2 DIABETES AND METABOLIC SYNDROME PATIENTS: A LATIN AMERICAN THYROID SOCIETY (LATS) POSITION STATEMENT

Prevalence and clinical correlates of thyroid dysfunction in first-episode and drug-naïve major depressive disorder patients with metabolic syndrome

BACKGROUND

Few studies have investigated the relative factors of thyroid dysfunction in major depressive disorder (MDD) patients with Metabolic syndrome (MetS). This study aimed to explore the prevalence and related factors associated with thyroid dysfunction in drug-naïve (FEDN) MDD patients with MetS.

METHODS

1718 FEDN MDD patients were recruited and their demographic data, clinical data were collected. Various biochemical indicators including fasting blood glucose (FBG), blood lipids and thyroid hormones were measured. The 17-item Hamilton Rating Scale for Depression (HAMD-17), 14-item Hamilton Anxiety Rating Scale (HAMA-14) and positive subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess clinical symptoms.

RESULTS

Among FEDN MDD patients, MetS was an independent risk factor for TSH abnormality (P < 0.001, Adjusted OR = 3.77, 95%CI: 2.82-5.05). In patients with MetS, those with TSH abnormality had significantly longer duration of illness, higher HAMD, HAMA, and PANSS positive subscale scores, higher levels of TC, LDL-C, blood glucose, pressure, lower levels of HDL-C, and a higher probability of suicide attempt (all P < 0.01).

CONCLUSIONS

MetS is significantly associated with thyroid dysfunction in patients with FEDN MDD. Related factors for thyroid dysfunction include a number of clinical indicators and psychiatric symptoms.

The role of the thyroid in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disease in women of childbearing age and can cause metabolic disorder, infertility, and increased anxiety and depression; as a result, it can seriously affect the physical and mental health of fertile women. PCOS is a highly clinically heterogeneous disease with unclear etiology and pathogenesis, which increases the difficulty of treatment. The thyroid gland has complex regulatory effects on metabolism, reproduction, and emotion, and produces hormones that act on almost all cells of the human body. The clinical manifestations of PCOS are similar to some thyroid diseases. Furthermore, some thyroid diseases, such as subclinical hypothyroidism (SCH), not only increase the incidence rate of PCOS, but also exacerbate its associated metabolic abnormalities and reproductive disorders. Interestingly, PCOS also increases the incidence of some thyroid diseases. However, the role of the thyroid in PCOS remains unclear. This review is intended to thoroughly explore the critical role of the thyroid in PCOS by summarizing the comorbidity of PCOS and thyroid diseases and their combined role in metabolic disorders, related metabolic diseases, and reproductive disorders; and by analyzing the potential mechanism through which the thyroid influences the development and progression of PCOS and its symptoms. We hope this review will provide a valuable reference for the role of the thyroid in PCOS.

Low glomerular filtration rate values are associated with higher TSH in an elderly population at high cardiovascular disease risk

Background

Hypothyroidism is associated with impaired glomerular filtration rate (GFR), a recognized cardiovascular disease (CVD), and mortality risk factor. In older adults, this association remains unexplored. We aimed to determine the relationship of elevated TSH with GFR in an elderly population at high CVD risk.

Methods

Older adults (age>65ys) with high CVD risk defined by two or more CVD risk factors: smoking (S), high blood pressure (HBP), high total cholesterol, low HDL cholesterol, diabetes (DM), metabolic syndrome or previous cardiovascular event, were prospectively included at our ambulatory Endocrine Clinic. Patients under levothyroxine or thyroid disease were excluded. TSH> 6mU/l defined subclinical hypothyroidism (ScH) with normal free T4 levels. Estimated GFR was calculated by the Berlin-Initiative Study (BIS)-1 formula for elderly population. Urinary albumin to creatinine ratio (uACR), IL-6 and TNF-α, and Carotid intima-media thickness (CIMT) were also determined. The U Mann-Whitney test, the Spearman test, and multiple linear regression were used as statistical tests.

Results

Finally 246 patients (68% females) were included and 20 (8%) had ScH. This group, was older (median, Q1-Q3: 77,72-78; 72,68-77 years, p=0.01) and DM was less frequent than in the euthyroid group (35 vs 58%, p=0.039). Lower fasting glucose (-20%,p=0.01), GFR (-14%,p=0.01) and freeT4 (-10%,p<0.001) were found compared to euthyroid patients. A higher prevalence of Kidney failure was found in ScH (80 vs. 46%, p=0.003) vs. euthyroid individuals. Significant correlations with GFR were detected: age (r-0.482,p<0.001), TSH (r-0.172,p=0.004), IL-6 (r-0.150,p=0.047), TNF-α (r-0.274,p<0.001), uACR (r-0.170,p=0.009) and CIMT(r-0.189,p=0.004). By multiple linear regression, in a model adjusted by age, sex, BMI, uACR, S, DM, TNF-α and HBP, TSH (Bst -0.14, p=0.023, R2 = 0.25) was found an independent predictor of GFR.

Conclusion

In older adults with high CVD risk, ScH is associated with lower renal function, and this relationship is present regardless of other cardiometabolic risk factors. These results suggest that ScH could contribute to low GFR and excess CVD risk, although this hypothesis should be addressed in longitudinal studies.

Potential Applications of Thyroid Hormone Derivatives in Obesity and Type 2 Diabetes: Focus on 3,5-Diiodothyronine (3,5-T2) in Psammomys obesus (Fat Sand Rat) Model

3,5-Diiodothyronine (3,5-T2) has been shown to exert pleiotropic beneficial effects. In this study we investigated whether 3,5-T2 prevent several energy metabolism disorders related to type 2 diabetes mellitus (T2DM) in gerbils diabetes-prone P. obesus. 157 male gerbils were randomly to Natural Diet (ND-controlled) or a HED (High-Energy Diet) divided in: HED- controlled, HED-3,5-T2 and HED- Placebo groups. 3,5-T2 has been tested at 25 µg dose and was administered under subcutaneous pellet implant during 10 weeks. Isolated hepatocytes were shortly incubated with 3,5-T2 at 10⁻⁶ M and 10⁻⁹ M dose in the presence energetic substrates. 3,5-T2 treatment reduce visceral adipose tissue, prevent the insulin resistance, attenuated hyperglycemia, dyslipidemia, and reversed liver steatosis in diabetes P. obesus. 3,5-T2 decreased gluconeogenesis, increased ketogenesis and enhanced respiration capacity. 3,5-T2 potentiates redox and phosphate potential both in cytosol and mitochondrial compartment. The use of 3,5-T2 as a natural therapeutic means to regulate cellular energy metabolism. We suggest that 3,5-T2 may help improve the deleterious course of obesity and T2DM, but cannot replace medical treatment.

Management of primary hypothyroidism in adults: An analysis of the results of a survey in 546 primary care physicians

OBJECTIVE

To document current practices in the management of adult patients with hypothyroidism in the setting of primary healthcare.

METHODS

We designed a web-based survey to inquire information on real-life practices regarding management of hypothyroidism by primary care physicians in the region of Madrid (Spain).

RESULTS

In total, 546 out of 3897 (14%) physicians (aged 50.9±8.5 yr, 404 females) completed the survey. More than 90% of respondents requested serum thyrotropin measurement in subjects with symptoms of thyroid hypofunction, family history of thyroid disease and history of autoimmune disease. A thyroid ultrasound was requested to evaluate subclinical and overt hypothyroidism by 27.1% and 69.6% of respondents, respectively. Only 22.1% of respondents stated that they do not treat subclinical hypothyroidism with thyrotropin values less than 10mU/l. Most physicians use brand-name formulations of levothyroxine and advise patients on how to take the tablets. To start treatment, the gradual replacement rate was the option chosen by most of the respondents, even in young patients. The thyrotropin target preferred by most respondents was 0.5-5.0mU/l, especially in older patients. In patients with persistent symptoms, 61.4% search for the causes through complementary investigations. A longer professional practice time was not always accompanied by better adherence to guidelines and expert recommendations.

CONCLUSION

Our results reveal a proactive attitude in the diagnosis and of therapy by most of the respondents. However, we observed a tendency to perform unnecessary diagnostic tests and an excessive propensity to treat mild subclinical hypothyroidism.

A practical contemporary approach to decision-making on subclinical hypothyroidism

Subclinical hypothyroidism (Shypo) is an increasingly frequent condition in common medical practice. Its diagnosis continues to pose a challenge since a series of non-thyroidal and temporary conditions can elevate serum TSH levels. In addition, the consequences of Shypo are still up for debate. Although detrimental cardiovascular effects have been consistently demonstrated in the young, they are less evident in older adults (65-79 years), and even more so in the oldest old (≥80 years). In the absence of evidence of any benefits of treating Shypo in patients' clinical manifestations and unfavorable outcomes, the most effective decision-making approach should include a thorough investigation of the patient's condition integrating all relevant clinical data, such as TSH levels, age, quality of life, comorbidities, cardiovascular risk, safety, and personal preferences. The decision-making process needs to take into account the risk of levothyroxine overtreatment and the resulting adverse consequences, such as reduction of bone mineral density, heart failure, and atrial fibrillation. Hence, current evidence suggests that individuals with TSH > 10 mU/L, who test positive for TPO Ab or are symptomatic may benefit from levothyroxine treatment. However, a more cautious and conservative approach is required in older (≥65 years of age), and oldest-old (≥80 years) patients, particularly those with frailty, in which the risk of treatment can outweigh potential benefits. The latter may benefit from a wait-and-see approach.

Management of primary hypothyroidism in adults: An analysis of the results of a survey in 546 primary care physicians

OBJECTIVE

To document current practices in the management of adult patients with hypothyroidism in the setting of primary healthcare.

METHODS

We designed a web-based survey to inquire information on real-life practices regarding management of hypothyroidism by primary care physicians in the region of Madrid (Spain).

RESULTS

In total, 546 out of 3897 (14%) physicians (aged 50.9±8.5 yr, 404 females) completed the survey. More than 90% of respondents requested serum thyrotropin measurement in subjects with symptoms of thyroid hypofunction, family history of thyroid disease and history of autoimmune disease. A thyroid ultrasound was requested to evaluate subclinical and overt hypothyroidism by 27.1% and 69.6% of respondents, respectively. Only 22.1% of respondents stated that they do not treat subclinical hypothyroidism with thyrotropin values less than 10mU/l. Most physicians use brand-name formulations of levothyroxine and advise patients on how to take the tablets. To start treatment, the gradual replacement rate was the option chosen by most of the respondents, even in young patients. The thyrotropin target preferred by most respondents was 0.5-5.0mU/l, especially in older patients. In patients with persistent symptoms, 61.4% search for the causes through complementary investigations. A longer professional practice time was not always accompanied by better adherence to guidelines and expert recommendations.

CONCLUSION

Our results reveal a proactive attitude in the diagnosis and of therapy by most of the respondents. However, we observed a tendency to perform unnecessary diagnostic tests and an excessive propensity to treat mild subclinical hypothyroidism.

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.

Biochemical and Ultrasound Characteristics of Subclinical Hypothyroid Patients in North of Jordan: Who Was Treated?

BACKGROUND

Early diagnosis and management of subclinical hypothyroidism (SCH) are important to avoid the risk of developing overt hypothyroidism. This study aimed to evaluate patients with subclinical hypothyroidism (SCH), in regard to their biochemical characteristics, and ultrasound features, and factors associated with initiating treatment for this condition.

METHODS

This was a retrospective study, which reviewed the data of patients who visited the Endocrinology clinic of a tertiary hospital in Jordan, King Abdullah University Hospital. Patients who visited the clinic with SCH over 1 year, Jan 2016-Dec 2016, were included. The charts were reviewed again 2 years later to check patients who started L-thyroxine for the different indications of treatment of SCH. Thyroid function tests (free T3, free T4, and TSH) and thyroid peroxidase antibodies (TPO-Ab) were found to be measured for all cases (n=287), among whom, thyroid ultrasound was done for 43 patients.

RESULTS

Most patients were females (88.1%). Mean age was 42.36 (±15.36 years). Positive TPO-Ab status was associated with higher TSH (p=0.056), lower free T4 levels (p= 0.012), and more patients treated with L- thyroxine for SCH in 2 years (p=0.001). On ultrasound, hypoechogenicity was more predominant among TPO-Ab positive patients than TPO-Ab negative patients (78% vs 30%).

CONCLUSION

SCH patients with positive TPO-Abs were more likely to be treated for this condition based on the various indications, and more likely to have had hypoechogenicity on ultrasound. Hence, thyroid ultrasonography and TPO-Ab status should be implemented early in evaluating and treating patients with SCH.

The role of thyroid hormone in metabolism and metabolic syndrome

Metabolic syndrome (MetS) and thyroid dysfunction are common in clinical practice. The objectives of this review are to discuss some proposed mechanisms by which thyroid dysfunctions may lead to MetS, to describe the bidirectional relationship between thyroid hormones (THs) and adiposity and finally, to resume a list of recent studies in humans that evaluated possible associations between thyroid hormone status and MetS or its clinical components. Not solely THs, but also its metabolites regulate metabolic rate, influencing adiposity. The mechanisms enrolled are related to its direct effect on adenosine triphosphate (ATP) utilization, uncoupling synthesis of ATP, mitochondrial biogenesis, and its inotropic and chronotropic effects. THs also act controlling core body temperature, appetite, and sympathetic activity. In a bidirectional way, thyroid function is affected by adiposity. Leptin is one of the hallmarks, but the pro-inflammatory cytokines and also insulin resistance impact thyroid function and perhaps its structure. MetS development and weight gain have been positively associated with thyroid-stimulating hormone (TSH) in several studies. Adverse glucose metabolism may be related to hyperthyroidism, but also to reduction of thyroid function or higher serum TSH, as do abnormal serum triglyceride levels. Hypo- and hyperthyroidism have been related to higher blood pressure (BP), that may be consequence of genomic or nongenomic action of THs on the vasculature and in the heart. In summary, the interaction between THs and components of MetS is complex and not fully understood. More longitudinal studies controlling each of all confounding variables that interact with endpoints or exposure factors are still necessary.

The insulin resistance is reversed by exogenous 3,5,3'triiodothyronine in type 2 diabetic Goto-Kakizaki rats by an inflammatory-independent pathway

PURPOSE

Diabetes mellitus (DM) has a multifactorial etiology that imparts a particular challenge to effective pharmacotherapy. Thyroid hormone actions have demonstrated beneficial effects in diabetic as well as obese rats. In both conditions, inflammation status plays a crucial role in the development of insulin resistance. Taking this into consideration, the present study aimed to demonstrate another possible pathway of thyroid hormone action on insulin sensitivity in a spontaneous type 2 diabetic rat model: the Goto-Kakizaki (GK) rats. GK animals present all typical hallmarks of type 2 DM (T2DM), except the usual peripheric inflammatory condition, observed in the other T2DM animal models.

METHODS

GK rats were treated or not with 3,5,3'triiodothyronine (T3). Insulin sensitivity, glucose tolerance, and proteins related to glucose uptake and utilization were evaluated in the skeletal muscle, white adipose tissue, and liver.

RESULTS

GK rats T3-treated presented enhanced insulin sensitivity, increased GLUT-4 content in the white adipose tissue and skeletal muscle, and increased hexokinase and citrate synthase content in skeletal muscle. Both non-treated and T3-treated GK rats did not present alterations in cytokine content in white adipose tissue, skeletal muscle, liver, and serum.

CONCLUSIONS

These results indicate that T3 improves insulin sensitivity in diabetic rats by a novel inflammatory-independent mechanism.

Protective Effects of Myo-Inositol and Selenium on Cadmium-Induced Thyroid Toxicity in Mice

Cadmium (Cd) damages the thyroid gland. We evaluated the effects of myo-inositol (MI), seleno-L-methionine (Se) or their combination on the thyroids of mice simultaneously administered with Cd chloride (CdCl₂). Eighty-four male mice were divided into 12 groups (seven mice each). Six groups (controls) were treated with 0.9% NaCl (vehicle), Se (0.2 mg/kg/day), Se (0.4 mg/kg/day), MI (360 mg/kg/day), MI+Se (0.2 mg/kg) and MI+Se (0.4 mg/kg). The other six groups were treated with CdCl₂ (2 mg/kg), CdCl₂+MI, CdCl₂+Se (0.2 mg/kg), CdCl₂+Se (0.4 mg/kg), CdCl₂+MI+Se (0.2 mg/kg) and CdCl₂+MI+Se (0.4 mg/kg). An additional group of CdCl₂-challenged animals (n= 7) was treated with resveratrol (20 mg/kg), an effective and potent antioxidant. All treatments lasted 14 days. After sacrifice, the thyroids were evaluated histologically and immunohistochemically. CdCl₂ reduced the follicular area, increased the epithelial height, stroma, and cells expressing monocyte chemoattractant protein-1 (MCP-1) and C-X-C motif chemokine 10 (CXCL10). CdCl₂+Se at 0.2/0.4 mg/kg insignificantly reversed the follicular and stromal structure, and significantly decreased the number of MCP-1 and CXCL10-positive cells. CdCl₂+MI significantly reversed the thyroid structure and further decreased the number of MCP-1 and CXCL10-positive cells. CdCl₂+MI+Se, at both doses, brought all indices to those of CdCl₂-untreated mice. MI, particularly in association with Se, defends mice from Cd-induced damage. The efficacy of this combination was greater than that of resveratrol, at least when using the follicular structure as a read-out for a comparison. We suggest that the use of these nutraceuticals, more specifically the combination of MI plus SE, can protect the thyroid of Cd-exposed subjects.