Subclinical hypothyroidism is mild thyroid failure and should be treated

Patient-Reported Satisfaction with Thyroid Hormone Replacement Therapy for Subclinical Hypothyroidism in Older Adults: A Pooled Analysis of Individual Participant Data from Two Randomized Controlled Trials

Background: The benefit of levothyroxine treatment of subclinical hypothyroidism (SCH) is subject to debate. This study compared treatment satisfaction between older adults with SCH using levothyroxine or placebo. Methods: We analyzed pooled individual participant data from two randomized, double-blind, placebo-controlled trials investigating the effects of levothyroxine treatment in older adults with SCH. Community-dwelling participants aged ≥65 years, with SCH (persistent thyrotropin levels 4.60-19.99 mIU/L for >3 months and normal free T4 level), were included. Intervention dose titration until thyrotropin levels normalized, with a mock dose adjustment of placebo. Treatment satisfaction was determined during the final study visit using the Treatment Satisfaction Questionnaire for Medication (TSQM), encompassing perceived effectiveness, side effects, convenience, and global satisfaction, along with the participants' desire to continue study medication after the trial. Results: We included 536 participants. At baseline, the median (interquartile range [IQR]) age was 74.9 (69.7-81.4) years, and 292 (55%) were women. The median (IQR) thyrotropin levels were 5.80 (5.10-7.00) mIU/L at baseline in both groups; at final visit, 4.97 (3.90-6.35) mIU/L in the placebo and 3.24 (2.49-4.41) mIU/L in the levothyroxine group. After treatment, the groups did not differ significantly in global satisfaction (mean difference [CI] -1.1 [-4.5 to 2.1], p = 0.48), nor in any other domain of treatment satisfaction. These results held true regardless of baseline thyrotropin levels or symptom burden. No major differences were found in the numbers of participants who wished to continue medication after the trial (levothyroxine 35% vs. placebo 27%), did not wish to continue (levothyroxine 27% vs. placebo 30%), or did not know (levothyroxine 37% vs. placebo 42%) (p = 0.14). In a subpopulation with high symptom burden from hypothyroid symptoms at baseline, those using levothyroxine more often desired to continue the medication after the trial than those using placebo (mean difference [CI]: -21.1% [-35.6% to -6.5%]). Conclusion: These pooled data from two RCTs showed no major differences in treatment satisfaction between older adults receiving levothyroxine or placebo. This finding has important implications for decision-making regarding initiating levothyroxine treatment for SCH. Our findings generally support refraining from routinely prescribing levothyroxine in older adults with SCH.

Deciphering the roles of triiodothyronine (T3) and thyroid-stimulating hormone (TSH) on cardiac electrical remodeling in clinical and experimental hypothyroidism

Hypothyroidism is the most frequent endocrine pathology. Although clinical or overt hypothyroidism has been traditionally associated to low T3 / T4 and high thyrotropin (TSH) circulating levels, other forms exist such as subclinical hypothyroidism, characterized by normal blood T3 / T4 and high TSH. In its different forms is estimated to affect approximately 10% of the population, especially women, in a 5:1 ratio with respect to men. Among its consequences are alterations in cardiac electrical activity, especially in the repolarization phase, which is accompanied by an increased susceptibility to cardiac arrhythmias. Although these alterations have traditionally been attributed to thyroid hormone deficiency, recent studies, both clinical trials and experimental models, demonstrate a fundamental role of TSH in cardiac electrical remodeling. Thus, both metabolic thyroid hormones and TSH regulate cardiac ion channel expression in many and varied ways. This means that the different combinations of hormones that predominate in different types of hypothyroidism (overt, subclinic, primary, central) can generate different forms of cardiac electrical remodeling. These new findings are raising the relevant question of whether serum TSH reference ranges should be redefined.

The ageing thyroid: implications for longevity and patient care

Thyroid hormones have vital roles in development, growth and energy metabolism. Within the past two decades, disturbances in thyroid hormone action have been implicated in ageing and the development of age-related diseases. This Review will consider results from biomedical studies that have identified the importance of precise temporospatial regulation of thyroid hormone action for local tissue maintenance and repair. Age-related disturbances in the maintenance of tissue homeostasis are thought to be important drivers of age-related disease. In most iodine-proficient human populations without thyroid disease, the mean, median and 97.5 centile for circulating concentrations of thyroid-stimulating hormone are progressively higher in adults over 80 years of age compared with middle-aged (50-59 years) and younger (20-29 years) adults. This trend has been shown to extend into advanced ages (over 100 years). Here, potential causes and consequences of the altered thyroid status observed in old age and its association with longevity will be discussed. In about 5-20% of adults at least 65 years of age, thyroid-stimulating hormone concentrations are elevated but circulating concentrations of thyroid hormone are within the population reference range, a condition referred to as subclinical hypothyroidism. Results from randomized clinical trials that have tested the clinical benefit of thyroid hormone replacement therapy in older adults with mild subclinical hypothyroidism will be discussed, as well as the implications of these findings for screening and treatment of subclinical hypothyroidism in older adults.

Hashimoto's Thyroiditis among Patients with Thyroid Disorders Visiting a Tertiary Care Centre

Introduction

Hashimoto's thyroiditis is a chronic autoimmune lymphocytic thyroiditis characterised by thyroid autoantibodies. Early detection and treatment of this condition help in reducing the morbidity and mortality associated with it. The aim of the study was to find out the prevalence of Hashimoto's thyroiditis among patients with thyroid disorders visiting a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted among patients visiting the outpatient department of a tertiary care centre. Data from 14 April 2017 to 13 April 2019 was collected between 30 June 2022 to 15 September 2022 from medical records. Ethical approval was obtained from the Nepal Health Research Council. Hashimoto's thyroiditis was diagnosed based on clinical presentation and positive antibodies to thyroid antigens. Convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval.

Results

Among 813 patients with thyroid disorders, 393 (48.33%) (44.89-51.77, 95% Confidence Interval) had Hashimoto's thyroiditis. The manifestation of the spectrum of Hashimoto's thyroiditis were euthyroid in 215 (54.70%), subclinical hypothyroidism in 102 (25.95%), subclinical hyperthyroidism in 23 (5.85%), overt hyperthyroidism in 9 (2.30%) and overt hypothyroidism in 4 (1.02%).

Conclusions

The prevalence of Hashimoto's thyroiditis among patients with thyroid disorders was higher than in other studies done in similar settings.

Keywords

anti-thyroid peroxidase antibodies; Hashimoto's thyroiditis; thyroid disorders.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Thymoquinone improved redox homeostasis in the heart and aorta of hypothyroid rats

OBJECTIVES

Propylthiouracil (PTU) is a common drug that is used in medicine for treating hyperthyroidism. Furthermore, hypothyroidism can also be induced with PTU. Considering the antioxidant effects of thymoquinone (TMQ), this study was designed to find out whether TMQ could counteract the oxidative damage in the heart and aorta tissues induced by hypothyroidism in rats.

METHODS

Animals were arranged into four groups: (1) Control, (2) PTU, (3) PTU-TMQ 5, and (4) PTU-TMQ 10. Hypothyroidism was induced in rats by giving 0.05% PTU in drinking water. PTU and TMQ (5 and 10 mg/kg, ip) treatments were done for 42 days. Finally, the animals were sacrificed and the serum of the rats was collected for thyroxine level assessment. The heart and aorta tissues were also removed for biochemical oxidative stress markers measurement.

RESULTS

A lower serum thyroxine level was observed after PTU treatment compared to the control group. Hypothyroidism also was accompanied by a decrease of thiol content, and superoxide dismutase (SOD), and catalase (CAT) activities in the heart and aorta tissues while increased malondialdehyde (MDA). Furthermore, a significant reduction in oxidative damage was noted in the heart and aorta following the administration of TMQ (5 and 10 mg/kg) which was indicated by the reduction in MDA and improved activities of SOD, CAT, and thiol.

CONCLUSION

In this study, TMQ was found to improve oxidative damages in the heart and aorta tissues of hypothyroid rats.

Cardiovascular protective effects of PPARγ agonists in hypothyroid rats: protection against oxidative stress

Hypothyroidism disturbs redox homeostasis and takes part in cardiovascular system dysfunction. Considering antioxidant and cardio-protective effects of PPAR-γ agonists including pioglitazone (POG) and rosiglitazone (RSG), the present study was aimed to determine the effect of POG or RSG on oxidants and antioxidants indexes in the heart and aorta tissues of Propylthiouracil (PTU)-induced hypothyroid rats.

MATERIALS AND METHODS

The animals were divided into six groups: (1) Control; (2) propylthiouracil (PTU), (3) PTU-POG 10, (4) PTU-POG 20, (5) PTU-RSG 2, and (6) PTU-RSG 4. Hypothyroidism was induced in rats by giving 0.05% propylthiouracil (PTU) in drinking water for 42 days. The rats of PTU-POG 10 and PTU-POG 20 groups received 10 and 20 mg/kg POG, respectively, besides PTU, and the rats of PTU-RSG 2 and PTU-RSG 4 groups received 2 and 4 mg/kg RSG, respectively, besides PTU. The animals were sacrificed, and the serum of the rats was collected to measure thyroxine level. The heart and aorta tissues were also removed for the measurement of biochemical oxidative stress markers.

RESULTS

Hypothyroidism was induced by PTU administration, which was indicated by lower serum thyroxine levels. Hypothyroidism also was accompanied by a decrease of catalase (CAT), superoxide dismutase (SOD) activities, and thiol concentration in the heart and aorta tissues while increased level of malondialdehyde (MDA). Interestingly, administration of POG or RSG dramatically reduced oxidative damage in the heart and aorta, as reflected by a decrease in MDA and increased activities of SOD, CAT, and thiol content.

CONCLUSION

The results of this study showed that administration of POG or RSG decreased oxidative damage in the heart and aorta tissues induced by hypothyroidism in rats.

High-Sensitive Detection and Quantitative Analysis of Thyroid-Stimulating Hormone Using Gold-Nanoshell-Based Lateral Flow Immunoassay Device

Au nanoparticles (AuNPs) have been used as signal reporters in colorimetric lateral flow immunoassays (LFAs) for decades. However, it remains a major challenge to significantly improve the detection sensitivity of traditional LFAs due to the low brightness of AuNPs. As an alternative approach, we overcome this problem by utilizing 150 nm gold nanoshells (AuNSs) that were engineered by coating low-density silica nanoparticles with a thin layer of gold. AuNSs are dark green, have 14 times larger surface area, and are approximately 35 times brighter compared to AuNPs. In this study, we used detection of thyroid-stimulating hormone (TSH) in a proof-of-concept assay. The limit of detection (LOD) with AuNS-based LFA was 0.16 µIU/mL, which is 26 times more sensitive than the conventional colorimetric LFA that utilizes AuNP as a label. The dynamic range of the calibration curve was 0.16−9.5 µIU/mL, making it possible to diagnose both hyperthyroidism (<0.5 µIU/mL) and hypothyroidism (>5 µIU/mL) using AuNS-based LFA. Thus, the developed device has a strong potential for early screening and diagnosis of diseases related to the thyroid hormone.

Low awareness and under-diagnosis of hypothyroidism

Hypothyroidism is a common condition with a prevalence that varies according to local dietary iodine availability, gender and age. The symptoms of hypothyroidism are generally nonspecific, with considerable overlap with other conditions and with the consequences for the health of advancing age. These symptoms are not useful for diagnosing hypothyroidism and a thyroid function test is required for a firm clinical diagnosis. Lack of knowledge and understanding of hypothyroidism, and a tendency for many people to attribute the symptoms of hypothyroidism to other causes have led to substantial unawareness and often late diagnosis of hypothyroidism. Large observational studies and meta-analyses have shown that about 4-7% of community-derived populations in the USA and Europe have undiagnosed hypothyroidism. About four cases in five of these are subclinical hypothyroidism, with the remainder being overt hypothyroidism. The prevalence of undiagnosed hypothyroidism is higher in older subjects, in women, and some ethnic groups, consistent with diagnosed disease. More research is needed to quantify the clinical burden of undiagnosed hypothyroidism around the world, with educational efforts aimed at the public and healthcare professionals aimed at identifying and managing these individuals.

Subclinical Hypothyroidism Affects Postoperative Outcome of Patients Undergoing Total Knee Arthroplasty

OBJECTIVE

The aim of this study was to investigate whether subclinical hypothyroidism could increase the risk of postoperative complications in patients undergoing primary total knee arthroplasty (TKA).

METHODS

A prospective case-control study of 796 patients undergoing primary TKA between January 2015 and January 2020 was performed. A total of 700 patients (87.9%) were female and the average age of included patients was 65.0 years, with a standard deviation of 5.6. The participants who had subclinical hypothyroidism were referred to as the case group, while those without abnormal thyrotropin (TSH) were included in the control group (matched for age and gender). The fasting plasma levels of TSH were tested in the morning in all patients. The diagnosis of subclinical hypothyroidism was completed by a senior endocrinologist based on laboratory tests; namely, a serum TSH ≥ 5 mu/L and normal free thyroxine (FT4). Subclinical hypothyroidism was further described as mild (TSH < 10 mu/L) or severe (TSH ≥ 10 mu/L). The incidence of 90-day postoperative complications was compared between two cohorts. Logistic regression analysis was used for the risk factors of 90-day postoperative complications following TKA.

RESULTS

A total of 398 patients had a diagnosis of subclinical hypothyroidism. Among them, 275 cases (69.1%) were described as mild (79 patients [19.8%] with low FT4 and 196 patients [49.2%] with normal FT4 in the repeated test) and 123 cases (30.9%) as severe subclinical hypothyroidism. Of the 196 patients (49.2%) with mild subclinical hypothyroidism and normal FT4, 63 patients (15.8%) had symptoms before surgery. Patients were followed up for an average duration of 25.4 months (6 to 43 months). A total of 265 patients (66.6%) received preoperative treatment for subclinical hypothyroidism, with an average therapy time of 9.2 months. There were 162 patients (40.7%) with positive autoantibodies to thyroid peroxidase (anti-TPO). There were no statistically significant differences in baseline data between cohorts (all P > 0.05). As for the cumulative 90-day outcomes, subclinical hypothyroidism increased the incidences of both medical and surgical complications following primary TKA compared to those without this condition (11.6% vs 7.2%, OR = 1.55, 95% confidence interval [CI] = 1.47-1.62, P < 0.05). Subclinical hypothyroidism caused patients to suffer increased total incidence of readmission within the first 90 days after discharge when compared to those without this condition (20.61% vs 14.15%, OR = 1.45, 95% CI = 1.41-1.49, P < 0.001). Controlling for preoperative and intraoperative variables, the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation were more likely to experience postoperative complications within 90 days of TKA.

CONCLUSION

Subclinical hypothyroidism might increase the risk of postoperative complications within 90 days of TKA, especially for the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation.

Assessment of Visual and Brainstem Auditory Evoked Potentials in Patients with Hashimoto's Thyroiditis

BACKGROUND

The present study was aimed to evaluate parameters of visual and brainstem auditory evoked potentials (VEP, BAEP) in euthyreotic Hashimoto's thyroiditis (HT) patients without central nervous system involvement.

METHODS

100 HT patients (92 women, 8 men), mean age 46.9 years, and 50 healthy controls. They underwent a neurological examination, thyroid hormone levels, thyroid autoantibody titers, and brain imaging. Latencies and amplitudes of the N75, P100, and N145 component of VEP and the I-V components of BAEP were analyzed.

RESULTS

The neurological examination revealed in 31 patients signs of increased neurovegetative excitability. Brain resonance imaging showed no abnormalities in HT patients. The mean P100, relative P100, and N145 VEP latencies were significantly longer, and P100 amplitude significantly higher in HT patients than the controls. HT patients also had a longer mean wave BAEP V latency and mean wave III-V and I-V interpeak latencies, and significantly lower mean wave I and V amplitudes. Abnormal VEP and BAEP were recorded in 34% of the patients. There were no statistically significant correlations between the mean VEP parameters and thyroid profile and the applied dose of L-thyroxine. There was a relationship between the level of TSH and the wave BAEP III-V interpeak latency.

CONCLUSIONS

There were changes in the brain's bioelectrical activity in one-third of the patients with HT without nervous system involvement. The increased amplitude of the VEP may indicate increased cerebral cortex activity. Disorders of the brain's bioelectrical activity in the course of HT may be associated with an autoimmune process.

Levothyroxine prescribing and laboratory test use after a minor change in reference range for thyroid-stimulating hormone

BACKGROUND

Prescribing of levothyroxine and rates of thyroid function testing may be sensitive to minor changes in the upper limit of the reference range for thyroid-stimulating hormone (TSH) that increase the proportion of abnormal results. We evaluated the population-level change in levothyroxine prescribing and TSH testing after a minor planned decrease in the upper limit of the reference range for TSH in a large urban centre with a single medical laboratory.

METHODS

Using provincial administrative data, we compared predicted volumes of TSH tests with actual TSH test volumes before and after a planned change in the TSH reference range. We also determined the number of new levothyroxine prescriptions for previously untreated patients and the rate of changes to the prescribed dose for those on previously stable, long-term levothyroxine therapy before and after the change in the TSH reference range.

RESULTS

Before the change in the TSH reference range, actual and predicted monthly volumes of TSH testing followed an identical course. After the change, actual test volumes exceeded predicted test volumes by 7.3% (95% confidence interval [CI] 5.3%-9.3%) or about 3000 to 5000 extra tests per month. The proportion of patients with newly "abnormal" TSH results almost tripled, from 3.3% (95% CI 3.2%-3.4%) to 9.1% (95% CI 9.0%-9.2%). The rate of new levothyroxine prescriptions increased from 3.24 (95% CI 3.15-3.33) per 1000 population in 2013 to 4.06 (95% CI 3.96-4.15) per 1000 population in 2014. Among patients with preexisting stable levothyroxine therapy, there was a significant increase in the number of dose escalations (p < 0.001) and a total increase of 500 new prescriptions per month.

INTERPRETATION

Our findings suggest that clinicians may have responded to mildly elevated TSH results with new or increased levothyroxine prescriptions and more TSH testing. Knowledge translation efforts may be useful to accompany minor changes in reference ranges.

Thyroid Dysfunction in Children with Idiopathic Nephrotic Syndrome Attending a Paediatric Hospital in Qazvin, Iran

Objectives

Nephrotic syndrome is a glomerular disease characterised by a loss of albumin and high-molecular-weight proteins such as thyroxine-binding globulin and thyroid hormones, potentially resulting in subclinical or even overt hypothyroidism. This study aimed to compare thyroid hormone levels between nephrotic children and healthy controls as well as between nephrotic children in the active phase of the disease and those in remission.

Methods

This case-control study was conducted between March 2016 and 2018 at a paediatric hospital in Qazvin, Iran. A total of 73 nephrotic children comprised the case group—including 49 with active disease and 24 in remission—while the control group included 74 healthy children. Thyroid function was assessed according to levels of thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4), total T4, total T3 and anti-thyroid peroxidase.

Results

All of the controls had normal total T4 levels. Elevated TSH levels were more frequent in nephrotic children compared to controls (34.2% versus 10.8%; P = 0.001). A significantly lower number of patients with active disease were euthyroid compared to those in remission (51% versus 95.8%; P = 0.001). Moreover, 7 (9.5%) of patients in the active and no patient in remission phase had abnormal total T4 levels (P <0.001), while 14.3% and 0% had highly elevated TSH levels (P = 0.002).

Conclusion

Due to the prevalence of subclinical and even overt hypothyroidism, thyroid screening tests may be required for nephrotic children. However, further research is needed to confirm these findings.

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

Background

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

Objectives

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

Method

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

Results

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

Conclusion

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

Cystatin C, a Controversial Biomarker in Hypothyroid Patients under Levothyroxine Therapy: THYRenal, a Pilot Cohort Observational Study

BACKGROUND

Cystatin C (Cys-C) is recognized as one of the most reliable renal function parameters in the general population, although it might be biased by thyroid status. Herein, we tested Cys-C and conventional renal parameters in a cohort of hypothyroid patients treated with Levothyroxine.

METHODS

Eighty-four hypothyroid patients were recruited and subgrouped according to their serum thyroid-stimulating hormone (TSH) values as a paradigm for therapeutic targeting (n = 54, optimal TSH range = 0.5-2 µIU/mL; n = 30, TSH > 2µIU/mL). Serum Cys-C, creatinine, measured and estimated glomerular filtration rates (mGFR and eGFR) were assessed. Results-mGFR and eGFR were comparable among the two subgroups, whereas Cys-C was significantly higher in patients with suboptimal TSH values (>2 µIU/mL) (p < 0.0001). TSH significantly correlated with Cys-C in the overall patient group, and in the subgroup with TSH above the target value (>2 µIU/mL). Out of 20 patients with abnormal Cys-C, 19 had suboptimal TSH levels. Receiver operating characteristic (ROC) analysis indicated Cys-C as a moderately accurate diagnostic tool (AUC = 0.871) to assess Levothyroxine replacement efficacy in hypothyroid patients (63% sensitivity, and 98% specificity).

CONCLUSIONS

The observation of increased serum Cys-C in patients with suboptimal TSH would suggest the importance of a careful interpretation by clinicians of this biomarker in the case of hypothyroid patients.

The current debate over treatment of subclinical hypothyroidism to prevent cardiovascular complications

BACKGROUND

Subclinical hypothyroidism (SCH) is an asymptomatic condition associated with increased thyroid-stimulating hormone (TSH) >4 mIU/L with normal thyroxine (T4) and triidothyronine (T3) levels. It is more common in older subjects and especially in women with an overall incidence of 10%.

OBJECTIVE

Because the normal TSH levels increase with age up to 7.5 mIU/L in older people, several studies have reported either no benefits whereas others have reported the benefits of treatment. These studies have caused a great debate over the treatment of SCH, especially in older subjects. Therefore, the objective of this study was to review the current evidence over this debate by reviewing the recent literature on the subject to discern whether treatment of SCH is necessary and under what circumstances.

METHODS

To get a better perspective on the current debate over treatment of SCH, a focused Medline search of the English language literature was conducted from 2012 to 2019 using the terms, hypothyroidism, subclinical, dyslipidaemia, cardiovascular disease, heart failure and 38 papers with pertinent information were selected.

RESULTS

The analysis of results from these papers indicated that the normal levels of TSH are increasing with the advancement of age from 4 mIU/L up to 7.5 mIU/L for patients ≥75 years of age. Also, several of reviewed studies have shown no benefits of treatment whereas, others have shown definite benefits of treatment with levothyroxine supplementation on the clinical and metabolic effects of SBH with reductions in CVD, HF and mortality. The treatment is more effective in younger persons and less so in older persons.

CONCLUSIONS

Based on the overall evidence, treatment of SCH is indicated in younger persons with a TSH level >4.0 mIU/L. In older subjects, treatment should be individualised and based on the presence of symptoms, the level of TSH, and initiated at TSH levels ≥10 mIU/L and at low doses to avoid adverse cardiovascular effects from overtreatment.

Effect of Thyroid Hormones on Kidney Function in Patients after Kidney Transplantation

Elevated levels of thyroid-stimulating-hormone (TSH) are associated with reduced glomerular filtration rate (GFR) and increased risk of developing chronic kidney disease even in euthyroid patients. Thyroid hormone replacement therapy has been shown to delay progression to end-stage renal disease in sub-clinically hypothyroid patients with renal insufficiency. However, such associations after kidney transplantation were never investigated. In this study the association of thyroid hormones and estimated GFR (eGFR) in euthyroid patients after kidney transplantation was analyzed. In total 398 kidney transplant recipients were assessed retrospectively and association between thyroid and kidney function parameters at and between defined time points, 12 and 24 months after transplantation, was studied. A significant inverse association was shown for TSH changes and eGFR over time between months 12 and 24 post transplantation. For each increase of TSH by 1 µIU/mL, eGFR decreased by 1.34 mL/min [95% CI, −2.51 to −0.16; p = 0.03], corresponding to 2.2% eGFR decline, within 12 months. At selected time points 12 and 24 months post transplantation, however, TSH was not associated with eGFR. In conclusion, an increase in TSH between 12 and 24 months after kidney transplantation leads to a significant decrease in eGFR, which strengthens the concept of a kidney-thyroid-axis.

Idiopathic post prandial glucose lowering, a whistle blower for subclinical hypothyroidism and insulin resistance. A cross-sectional study in Tertiary Care Centre of northeast India

Background and Aims:

There has been a lot of confusion in management of apparently healthy individuals whose post prandial plasma glucose levels were lower than fasting levels. It has been observed that many clinicians do send for repeat tests to rule out analytical error since there is common knowledge that post prandial glucose should be higher than fasting glucose level. Blood glucose level is regulated by a fully integrated mechanism with complex interplay of hormones and enzymes on metabolic pathways. Increase or decrease of thyroid hormones can break this equilibrium leading to alterations of carbohydrate metabolism. The objective for this study was to look for subclinical hypothyroidism (SCH) and insulin resistance (IR) in Idiopathic Post prandial glucose lowering and the correlation between thyroid stimulating hormone (TSH) with IR in them.

Methods:

A cross-sectional study with subgroup analysis, 34 cases and 34 controls. Cases comprises of otherwise healthy individuals whose post prandial glucose is lower than fasting glucose and controls as those healthy individual whose post prandial glucose is higher than fasting. Thyroid hormones and insulin were measured in fasting serum samples. Homeostasis model assessment for IR was calculated as per formula.

Results:

Among the 34 cases with idiopathic post prandial glucose lowering, 76% (n = 26) had subclinical hypothyroidism and 61% (n = 21) had insulin resistance. A positive correlation (r = 0.55) was observed between Thyroid-Stimulating hormone (TSH) and Index of insulin resistance and homeostatic model assessment (HOMA-IR) and was statistically significant with P < 0.1.

Conclusions:

The study highlights the importance of evaluating glycoregulatory hormones like thyroid hormones and insulin in cases with idiopathic post prandial glucose lowering for early diagnosis and prevention of overt clinical diseases like Hypothyroidism and Diabetes Mellitus.

Assessment of subclinical hypothyroidism for a clinical score and thyroid peroxidase antibody: a comparison with euthyroidism grouped by different thyroid-stimulating hormone levels

Background

Subclinical hypothyroidism (SCH) might have many symptoms of hypothyroidism. The controversy appears to lower the level of thyroid-stimulating hormone (TSH) and group subjects with TSH of more than 3 or even 2.5 mIU/L as SCH subjects.

Objectives

To assess SCH subjects both clinically using Zulewski clinical score and biochemically and to evaluate whether the euthyroid subjects with high-normal TSH (HNT) have any clinical symptom or subnormal biochemical finding.

Methods

A prospective cross-sectional study of 233 subjects, 67 with SCH and 166 euthyroidism, was conducted. Euthyroid subjects were divided according to the level of TSH as HNT (>2.5 mIU/L) and low-normal TSH (0.5–2.5 mIU/L). The subjects were examined for clinical feature including Zulewski clinical score and biochemical evaluations including thyroid peroxidase antibody (TPO-Ab) titer. The comparisons between groups were assessed using independent sample t test, and correlations between variables were evaluated using Pearson correlation.

Results

A significantly higher clinical score and higher frequencies of symptoms were found in the SCH group compared to the euthyroid group. The most frequent symptom was fatigue. Euthyroid subjects with HNT were found to have higher TPO-Ab titers than those with low-normal TSH, P < 0.05. The Zulewski clinical score was positively correlated with TSH and TPO-Ab titer but negatively correlated with the FT4 level, P < 0.05.

Conclusions

Zulewski clinical score is higher in SCH subjects compared to euthyroid subjects and can aid in assessing SCH subjects. A significant correlation exists between Zulewski clinical score and each of the TSH, FT4, and TPO-Ab titer levels. The frequency of TPO-Ab positivity is high in SCH. Additionally, euthyroid with higher TSH levels has higher level of TPO-Ab titer but not higher clinical score.

Thyroid stimulating hormone values of clinical decisions of hypothyroidism measurement by three different automated immunoassays

Background: An accurate measurement of serum thyroid stimulating hormone (TSH) is crucial for a thyroid disorder diagnosis and management. We compared the values of TSH between three automated immunoassays with aims to provide insights into variations in TSH levels that are important for a clinical decision: 2.50 mIU/L, 4.00 mIU/L and 10.00 mIU/L.Methods: We measured TSH with three different fully automated immunoassays: Abbott (Architect ci8200), Siemens (ADVIA Centaur XP) and Roche (Cobas e411). Serum was collected from 110 patients between August 2018 and January 2019. The results were compared using the Passing-Bablok regression method. Additionally, linear regression coefficients were calculated after logarithmic transformation of data.Results: Although all three regression coefficients were high (r² > 0.98), the slopes from Passing-Bablok plots for the correlation of Abbott with either Roche or Siemens were merely 0.66 and 0.73, respectively. The slope for the correlation of Roche and Siemens was 1.11. Consecutively, the results obtained by the Roche and Siemens methods were proportionally higher than those obtained by the Abbott method (38% and 52%, respectively) at all measured ranges.Conclusions: Although immunoassays correlated among themselves, they cannot achieve the same values for clinical decisions for hypothyroidism (clinical requirements). Clinicians should be conscious of these limitations. A harmonisation of the methods is needed to meet clinical requirements and to enable appropriate clinical decisions in cases of hypothyroidism.Likewise, we suggest the introduction of borderline and high risk values of TSH for hypothyroidism depending on immunoassays to avoid misdiagnosis.

Thyroid disease and the metabolic syndrome

PURPOSE OF REVIEW

To summarize recent developments in the association of thyroid function with metabolic syndrome (MetS).

RECENT FINDINGS

Although thyroid hormones even within low normal range are associated with various metabolic abnormalities, the risk of MetS remains a controversial issue. Hyperthyroid state might be associated only with insulin resistance and dysglycemia. Autoimmune thyroid diseases may be a potential risk factor for metabolic abnormalities even in those with low normal thyroid function.

SUMMARY

The interrelation between thyroid stimulating hormone, free T3, freeT4 and metabolic parameters is complex and might be affected by age, sex, BMI, insulin resistance, smoking, iodine intake and inflammatory markers.

A Cross-Sectional Study to Assess the Prevalence of Adult Thyroid Dysfunction Disorders in Jordan

Background: Insufficient production of thyroid hormones results in hypothyroidism, while overproduction results in hyperthyroidism. These are common adult disorders, with hypothyroidism more common in the elderly. Jordan has had past problems with dietary iodine deficiency but there are no published studies assessing the population prevalence of these disorders in the Arab Middle East. Methods: A cross-sectional study was conducted in three representative areas of Jordan. There were 7085 participants with a mean age of 40.8 years. Participants completed a questionnaire and had blood taken for thyroid analysis. Results:Hypothyroidism: The prevalence of any hypothyroidism (already diagnosed and/or identified by blood testing) was 17.2% in females and 9.1% in males. Undiagnosed prevalence was 8% and 6.2% for females and males, respectively. The prevalence of subclinical hypothyroidism, defined as high serum thyrotropin (TSH) and normal serum-free thyroxine (fT4), was 5.98% among females and 4.40% among males. The prevalence of overt hypothyroidism, defined as high TSH and low fT4, was 2.00% among females and 1.80% among males. Only 53.5% (55.3% for females, 42.1% males) of those previously diagnosed with hypothyroidism had TSH levels within the appropriate range. Hyperthyroidism: The prevalence of any hyperthyroidism (already diagnosed and/or identified by blood testing) was 1.8% in females and 2.27% in males. The undiagnosed prevalence was 1.4% and 2.1% for females and males, respectively. The prevalence of subclinical hyperthyroidism (low TSH and normal fT4) was 1.20% and 1.80% among males and females accordingly. The prevalence of overt hyperthyroidism (low TSH and high fT4) was 0.2% among females and 0.3% among males. About 85.7% (83.3% for females, 100% males) of those previously diagnosed with hyperthyroidism had TSH levels within the appropriate range. Conclusions: The results of this study reveal that the total prevalence of thyroid dysfunction among adult females and males in Jordan is very high compared with international statistics, particularly in the rates of undiagnosed cases. This indicates the need for further assessment of the value of screening for adult hypothyroidism in Jordan.

Significance of Anti-TPO as an Early Predictive Marker in Thyroid Disease

Even though most thyroid subjects are undiagnosed due to nonspecific symptoms, universal screening for thyroid disease is not recommended for the general population. In this study, our motive is to showcase the early appearance of thyroid autoantibody, anti-TPO, prior to the onset of thyroid hormone disruption; hence the addition of anti-TPO in conjunction with traditional thyroid markers TSH and FT4 would aid to reduce the long-term morbidity and associated health concerns. Here, a total of 4581 subjects were tested multiple times for TSH, FT4, anti-TPO, and anti-Tg and followed up for 2 years. We streamlined our subjects into two groups, A1 (euthyroid at first visit, but converted to subclinical/overt hypothyroidism in follow-up visits) and A2 (euthyroid at first visit, but converted to hyperthyroidism in follow-up visits). According to our results, 73% of hypothyroid subjects (from group A1) and 68.6% of hyperthyroid subjects (from group A2) had anti-TPO 252 (±33) and 277 (±151) days prior to the onset of the thyroid dysfunction, respectively. Both subclinical/overt hypothyroidism and hyperthyroidism showed a significantly higher percentage of subjects who had anti-TPO prior to the onset of thyroid dysfunction compared to the combined control group. However, there was no significant difference in the subjects who had anti-Tg earlier than the control group. Further assessment showed that only anti-TPO could be used as a standalone marker but not anti-Tg. Our results showcase that anti-TPO appear prior to the onset of thyroid hormone dysfunction; hence testing anti-TPO in conjunction with TSH would greatly aid to identify potentially risk individuals and prevent long-term morbidity.

The effect of levothyroxine treatment on left ventricular function in subclinical hypothyroidism

OBJECTIVE

Treatment of subclinical hypothyroidism (ScH), especially the mild form of ScH, is controversial because thyroid hormones influence cardiac function. We investigate left ventricular systolic and diastolic function in ScH and evaluate the effect of 5-month levothyroxine treatment.

SUBJECTS AND METHODS

Fifty-four patients with newly diagnosed mild ScH (4.2 <TSH < 10.0 mU/L) and 30 euthyroid subjects matched by age were analysed. Laboratory analyses and an echocardiography study were done at the first visit and after 5 months in euthyroid stage in patients with ScH.

RESULTS

Compared to healthy controls, patients with ScH had a lower E/A ratio (1.03 ± 0.29 vs. 1.26 ± 0.36, p < 0.01), higher E/e' sep. ratio (762 ± 2.29 vs. 6.04 ± 1.64, p < 0.01), higher myocardial performance index (MPI) (0.47 ± 0.08 vs. 0.43 ± 0.07, p < 0.05), lower global longitudinal strain (GLS) (-19.5 ± 2.3 vs. -20.9 ± 1.7%, p < 0.05), and lower S wave derived by tissue Doppler imaging (0.077 ± 0.013 vs. 0.092 ± 0.011 m/s, p < 0.01). Levothyroxine treatment in patients with ScH contributed to higher EF (62.9 ± 3.9 vs. 61.6 ± 4.4%, p < 0.05), lower E/e' sep. ratio (6.60 ± 2.06 vs. 762 ± 2.29, p < 0.01), lower MPI (0.43 ± 0.07 vs. 0.47 ± 0.08%, p < 0.01), and improved GLS (-20.07 ± 2.7 vs. -19.55 ± 2.3%, p < 0.05) compared to values in ScH patients at baseline. Furthermore, in all study populations (ScH patients before and after levothyroxine therapy and controls), TSH levels significantly negatively correlated with EF (r = -0.15, p < 0.05), E/A (r = -0.14, p < 0.05), GLS (r = -0.26, p < 0.001), and S/TDI (r = -0.22, p < 0.01) and positively correlated with E/e' sep. (r = 0.14, p < 0.05).

CONCLUSION

Patients with subclinical hypothyroidism versus healthy individuals had subtle changes in certain parameters that indicate involvement of systolic and diastolic function of the left ventricle. Although the values of the parameters were in normal range, they were significantly different compared to ScH and the control group at baseline, as well as to the ScH groups before and after treatment.The results of our study suggest that patients with ScH must be followed up during treatment to assess improvement of the disease. Some of the echocardiography obtained parameters were reversible after levothyroxine therapy.

The role of functional thyroid capacity in pituitary thyroid feedback regulation

BACKGROUND

Thyroid feedback regulation and equilibria between thyroid hormones differ in the presence or absence of a functioning thyroid remnant.

MATERIALS AND METHODS

This study examines the relationship between the sensitivity of TSH feedback and thyroid capacity in untreated patients with thyroid autoimmune disease (n = 86) and healthy controls (n = 271). Functional capacity was estimated at maximum TSH stimulation, and pituitary TSH response was FT4-standardised with two established indices, the TSH index and the thyrotroph thyroid hormone resistance index.

RESULTS

The two indices correlated inversely with thyroid volume and functional thyroid capacity. Relationships were shifted upwards in patients with thyroid autoimmune disease. This positioned patients with thyroid autoimmune disease predominantly at the lower capacity range and upper part of TSH index. The relationship was modulated by serum FT3 concentrations, shifting 0.19 [95%CI: 0.12, 0.26] mIU/L per pmol FT3 increase. FT3 correlated with TSH index in total group ( τ  = 0.09, P = 0.009) and both subgroups. FT3 levels were maintained despite a substantial capacity loss by progressively increasing conversion rates of T3 from T4, only collapsing at capacities below <1.5 pmol/s.

CONCLUSION

Functional thyroid capacity and preferential T3 generation are essential elements in adjusting the sensitivity of hypothalamic-pituitary-thyroid feedback control and balancing system equilibria. This suggests that the indirect regulatory role of glandular T3 co-secretion exceeds its quantitative contribution to the thyroid hormone pool. Implications for clinical practice extend to the diagnostic use of TSH in patients with impaired thyroid reserve.

The association between subclinical hypothyroidism and erectile dysfunction

Objectives

Erectile dysfunction (ED) is highly prevalent among males, and hypothyroidism is previously reported to be related with ED. However there have been rare studies to investigate the association between subclinical hypothyroidism (SCH) and ED, hence our objective was to fill this gap.

Methods

ED patients who visited the Urology Outpatients Clinic owere recruited consecutively, and males from the Health Manage Center were included as the controls. Serum thyroid and sexual hormones were estimated, and the International Index of Erectile Function (IIEF-5) questionnaires were evaluated as well. Subjects with normal sexual hormones were included for statistical analysis.

Results

One hundred nine ED patients and 32 healthy controls were included in this study. The ratio of SCH and euthyroidism in ED males was 29.36% and 66.06% respectively. The IIEF-5 scores in ED patients with SCH were significantly lower than the controls with euthyroidism (P<0.05). The serum concentrations of TSH and prolactin were significantly higher and free thyroxine lower in ED patients with SCH when compared with the controls with euthyroidism (all p<0.05), and no significant differences of estradiol and total testosterone were found between those two groups. However the IIEF-5 scores were not significantly different between males with SCH and euthyroidism among ED patients (P>0.05).

Conclusions

SCH is common in ED patients and may be associated with ED, whereas the severity of ED is not related to SCH. Screening for thyroid dysfunction in men presenting with ED is recommended.

Treatment with levothyroxin in subclinical hypothyroidism is associated with increased mortality in the elderly

INTRODUCTION

It is uncertain whether subclinical hypothyroidism should be treated with levothyroxine, particularly in the elderly. This study evaluated the association between levothyroxine treatment and mortality in individuals 65years or older with subclinical hypothyroidism and TSH values <10mIU/L.

METHODS

A case-control study in which patients 65years or older with TSH levels of 4.2-10mIU/L who died in the years 2012-2016 ('cases') were compared with matched individuals who did not die during this period ('controls'). Matching was based on gender, age, Charlson comorbidity index, date of TSH testing, duration of follow-up and TSH quartile. All cases of known thyroid disease or cases in which anti-thyroid medications or glucocorticoids were dispensed in the year preceding the TSH evaluation were excluded. Use of levothyroxine was compared between groups.

RESULTS

During the follow-up period, 419 individuals died and these were matched with 1558 individuals who did not. Factors found to be associated with mortality were age, senile dementia, congestive heart failure, chronic renal failure and a history of cerebrovascular disease. On multivariate analysis, treatment with levothyroxine was associated with significantly increased mortality (HR=1.19 CI 1.03-1.38). Femoral fractures and atrial fibrillation following initiation of levothyroxine therapy were not more prevalent in individuals who died during the follow-up period.

CONCLUSIONS

Treatment with levothyroxine is associated with significantly increased mortality in individuals 65years or older with subclinical hypothyroidism and TSH<10.

Evaluation of renal function in subclinical hypothyroidism

INTRODUCTION

Patients with subclinical hypothyroidism (SCH) have a few or no symptoms or signs of thyroid dysfunction and thus by its very nature, SCH is a laboratory diagnosis. Serum creatinine is elevated and glomerular filtration rate (GFR) values are reversibly reduced in overt hypothyroid patients. We hypothesize that SCH also may be associated with low GFR.

AIMS AND OBJECTIVES

The objective of this study was (1) to know the effect of SCH on kidney function, (2) to find the correlation between the renal function parameter creatinine, estimated GFR (eGFR), and thyroid-stimulating hormone (TSH), and (3) to know if creatinine values can be predicted by TSH values in SCH cases.

MATERIALS AND METHODS

This is a hospital-based cross-sectional study for 1 year. A total of 608 subjects of either sex were included in the study and were divided into 3 groups: (1) SCH, (2) overt hypothyroidism (OHT), and (3) euthyroidism (ET). TSH, free triiodothyronine, free thyroxine, and serum creatinine were estimated and eGFR was calculated using modification of diet in renal disease study equation and the chronic kidney disease epidemiology collaboration equations.

RESULTS

Serum creatinine levels were higher and eGFR was lower significantly in the subclinical hypothyroid group when compared to the control ET group (P < 0.001). The overtly hypothyroid group had significantly higher levels of serum creatinine and lower eGFR when compared to both the groups (P < 0.001). Significant correlation between TSH, creatinine, and eGFR was found in OHT group only. Linear regression analysis showed the regression in creatinine upon TSH is attributable to 44.5% among OHT group, 48.2% in SCH group.

CONCLUSION

It can be concluded that the SCH group behaves biochemically similar to OHT group and changes in serum creatinine reflect tissue hypothyroidism in SCH cases.

Vitamin E improved redox homeostasis in heart and aorta of hypothyroid rats

OBJECTIVES

The objective of this study was to evaluate the effect of vitamin E on the oxidative stress parameters and antioxidant defense enzymes in the heart and aorta of 6-n-propylthiouracil (PTU)-induced hypothyroid rats.

METHODS

The animals were divided into 4 experimental groups: Group 1 (Euthyroid) received tap water, Group 2 (Hypothyroid) received 0.05 % of PTU in dissolved in their drinking water, Group 3 (PTU+Vit E) hypothyroid rats treated with vitamin E, and Group 4 (Euthyroid+Vit E). Vitamin E was injected daily (20 mg/kg) to groups 3 and 4 via daily gavage for 6 weeks. Malondialdehyde (MDA) levels, total thiol levels, and the activities of Cu, Zn-superoxide dismutase (SOD) and catalase (CAT) were evaluated in the aortic and cardiac tissues.

RESULTS

A significant decrease of thyroxine (T4) serum levels confirmed hypothyroidism in rats, which received PTU. The MDA level increased and total thiol level decreased in the hypothyroid group compared to control group (p<0.001). Th e activities of SOD and CAT significantly decreased in the hypothyroid rats in comparison to the control. Vitamin E treatment resulted in increased levels of total thiol, SOD, and CAT within aortic and cardiac tissues and decreased levels of MDA in comparison with the hypothyroid group (p<0.01-p<0.001).

CONCLUSIONS

PTU-induced hypothyroidism resulted in oxidative stress. Chronic administration of vitamin E to hypothyroid rats decreased the oxidative stress markers in the aortic and cardiac tissues.

Subclinical Hypothyroidism - Whether and When To Start Treatment?

Subclinical hypothyroidism represents a state with increased values of thyroid stimulating hormone (TSH) and normal values of thyroxine (T4) and triiodothyronine (T3). The disorder is asymptomatic, and the diagnosis is made based on the results of laboratory findings when the level of TSH reaches values above 4.0 mU/l. It is still subject to debate whether patients with subclinical hypothyroidism are at increased risk of cardiovascular disease, neuropsychiatric and neuromuscular disorders. Studies have shown that the appearance of general symptoms and complications are more common in patients whose values of TSH are above 10 mU/l. Therefore, the initiation of therapy with levothyroxine, which is the foundation of substitution therapy, is advised in patients whose TSH is >10 mU/l. As for patients whose values of TSH are from 4.0 to 10.0 mU/l and who make up 90% of the patients with subclinical hypothyroidism, further research is needed to determine the effects of the disorder and levothyroxine therapy on the health. Until then, the introduction of the substitution therapy in patients with TSH which is <10 mU/l should be considered in the case of the presence of general symptoms, anti-thyroid antibodies, increased lipids and other risk factors, goitre, pregnancy, ovarian dysfunction and infertility.

Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial

BACKGROUND

Subclinical hypothyroidism, a thyroid disorder without obvious symptoms of thyroid deficiency, occurs in 3%-8% of the global population. Ashwagandha [Withania somnifera (L.) Dunal], a traditional medicine in Ayurveda, is often prescribed for thyroid dysfunctions.

OBJECTIVE

This pilot study was designed to evaluate the efficacy and safety of ashwagandha root extract in subclinical hypothyroid patients.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, randomized, double-blind, single-center placebo-controlled study was performed at Sudbhawana Hospital, Varanasi, India between May 2016 and September 2016. Fifty subjects with elevated serum thyroid stimulating hormone (TSH) levels (4.5-10 μIU/L) aged between 18 and 50 were randomized in either treatment (n = 25) or placebo (n = 25) groups for an 8-week treatment period.

INTERVENTIONS

Ashwagandha root extract (600 mg daily) or starch as placebo. Efficacy Variables: Serum TSH, serum triiodothyronine (T3), and thyroxine (T4) levels.

RESULTS

A total of four subjects (two from each group) withdrew their consent before the second visit. Eight weeks of treatment with ashwagandha improved serum TSH (p < 0.001), T3 (p = 0.0031), and T4 (p = 0.0096) levels significantly compared to placebo. Ashwagandha treatment effectively normalized the serum thyroid indices during the 8-week treatment period in a significant manner (time-effects: TSH [p < 0.001], T3 [p < 0.001], and T4 [p < 0.001]). Four subjects (8%) (ashwagandha: 1[4%]; Placebo: 3[12%]) out of 50 reported few mild and temporary adverse effects during this study.

CONCLUSION

Treatment with ashwagandha may be beneficial for normalizing thyroid indices in subclinical hypothyroid patients.

The debate on treating subclinical hypothyroidism

Subclinical hypothyroidism (SCH) represents a mild or compensated form of primary hypothyroidism. The diagnosis of SCH is controversial, as its symptoms are non-specific and its biochemical diagnosis is arbitrary. The treatment of SCH was examined among non-pregnant adults, pregnant adults and children. In non-pregnant adults, treatment of SCH may prevent its progression to overt hypothyroidism, reduce the occurrence of coronary heart disease, and improve neuropsychiatric and musculoskeletal symptoms associated with hypothyroidism. These benefits are counteracted by cardiovascular, neuropsychiatric and musculoskeletal side effects. SCH is associated with adverse maternal and fetal outcomes that may improve with treatment. Treating SCH in children is safe and may improve growth. Importantly, the evidence in this field is largely from retrospective and prospective studies with design limitations, which precludes a conclusive recommendation for the treatment of SCH.

Echocardiographic evaluation of left ventricular diastolic dysfunction in subclinical hypothyroidism: A case-control study

PURPOSE

To study the prevalence of left ventricular diastolic dysfunction (LVDD) in patients with subclinical hypothyroidism (SCH) and the response of LVDD to L-thyroxine therapy.

MATERIALS AND METHODS

This cross-sectional case-control study with one longitudinal arm included 67 patients with SCH attending a tertiary care hospital in Uttarakhand, India, and 67 age- and sex-matched healthy controls. LVDD was assessed by 2D, pulsed-wave Doppler (PWD), continuous wave Doppler (CWD), and tissue Doppler echocardiography (TDE). Patients with LVDD received L-thyroxine therapy with reassessment for LVDD 6 months later.

RESULTS

SCH patients had a higher prevalence of LVDD than controls (13.43% versus 1.49%; p = 0.017). LVDD showed a significant association with gender (p = 0.004) and serum FT4 (p = 0.001). E velocity, E' velocity, A' velocity, iso-volumetric relaxation time (IVRT), E/A, and E'/A' ratios were significantly lower, while A velocity, deceleration time (DT), E/E' ratio, left atrial (LA) volume index, and peak tricuspid regurgitation (TR) velocity were significantly higher in cases than controls (p < 0.05 each). The E/A ratio correlated significantly with age, serum very low-density lipoprotein (VLDL), triglycerides (TG), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and high-density lipoprotein (HDL) (p < 0.05 each). E' velocity correlated significantly with age, serum total cholesterol, VLDL, and TG (p < 0.05 each), DT with serum total cholesterol (p = 0.047), and LA volume index with age (p = 0.021). Age (p = 0.016) and serum HDL (p = 0.029) were independent predictors of E/A ratio. Gender was an independent predictor for LVDD (p = 0.003). Echocardiographic indices for LVDD showed significant improvement after 6 months of L-thyroxine therapy (p < 0.05 each).

CONCLUSIONS

LVDD occurs commonly in SCH patients. It can be detected timely using echocardiography and may be reversed by L-thyroxine therapy.

Association of Thyroid-Stimulating Hormone Levels with Microvascular Complications in Type 2 Diabetes Patients

BACKGROUND Subclinical hypothyroidism (SCH) is typically featured by elevated serum concentration of thyroid-stimulating hormone (TSH). This study aimed to determine the relationship between TSH levels and microvascular complications in type 2 diabetes patients. MATERIAL AND METHODS A total of 860 type 2 diabetes patients were enrolled in this cross-sectional study. Subjects were evaluated for anthropometric measurements, thyroid function, diabetic retinopathy, and diabetic kidney disease. TSH was divided into 3 levels: 0.27-2.49 mU/l, 2.5-4.2 mU/l, and >4.2 mU/l. RESULTS Among the participants, 76 subjects (8.8%) were diagnosed with subclinical hypothyroidism (SCH) (male: 6.6% and female: 11.8%). The prevalence of diabetic retinopathy did not differ among the groups (P=0.259). Of the 860 type 2 diabetic subjects, we further excluded invalid or missing data. Therefore, 800 and 860 subjects were included in our study of diabetic retinopathy (DR) and diabetic kidney disease (DKD), respectively. The frequencies of microalbuminuria and macroalbuminuria differed significantly among the different groups. The frequency of DKD was significantly different among the 3 groups (P=0.001) and was higher in subjects with higher TSH levels. After an adjustment for confounding variables, TSH levels were significantly associated with DKD (P<0.001). When compared with subjects with TSH 0.27-2.49 mU/l, the frequency of DKD was higher in subjects with TSH >4.20 mU/l (OR 1.531, 95% CI 1.174-1.997) and with TSH 2.50-4.20 mU/l (OR 1.579, 95% CI 1.098-2.270). However, TSH levels was not significantly correlated with DR (P=0.126). CONCLUSIONS Type 2 diabetic patients with higher TSH values had a higher prevalence of DKD.

The TSH levels and risk of hypothyroidism: Results from a population based prospective cohort study in an Iranian adult's population

OBJECTIVE

The aim of current study was to assess the relationship between serum TSH levels and hypothyroidism risk in the euthyroid population.

METHODS

In a population-based cohort study, a total of 615 individuals with a normal baseline TSH, from of total population (n=2254) in 2006, were followed up for 6years. TSH, total T4, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured. The relative risk (RR) and 95% confidence interval (95%CI) were calculated based on logistic regression. The Receiver Operating Characteristic (ROC) analysis along with area under the curve (AUC) was used to prediction of future hypothyroidism.

RESULTS

TSH level in 2006 was a significant predictor for overt hypothyroidism, in the total population (RR=3.5) and female (RR=1.37) (all, P value<0.05). A cutoff value of TSH at 2.05mIU/L [AUC: (CI95 %), 0.68 (0.44-0.92; P=0.05)] was obtained for differentiating the patients with overt hypothyroidism from euthyroid. However, this cut off was not observed when we included only negative TPO and TgAbs people in 2006. The RR of hypothyroidism increased gradually when TSH level increased from 2.06-3.6mIU/L to >3.6mIU/L in the total population and both sexes. In women, the risk of overt hypothyroidism was significantly higher in subjects with TSH above 3.6 than those subject with THS levels≤2.05 [RR: (CI95 %), 20.57(2.-207.04), P value<0.05].

CONCLUSION

A cutoff value of TSH at 2.05mIU/L could predict the development of overt hypothyroidism in future. However, it was not applicable for people with negative TPOAb and negative TgAb.

The Thyroid Registry: Clinical and Hormonal Characteristics of Adult Indian Patients with Hypothyroidism

OBJECTIVES

Appropriate treatment of hypothyroidism requires accurate diagnosis. This registry aimed to study the disease profile and treatment paradigm in hypothyroid patients in India.

MATERIALS AND METHODS

We registered 1500 newly diagnosed, treatment-naïve, adult hypothyroid males and nonpregnant females across 33 centers and collected relevant data from medical records. The first analysis report on baseline data is presented here.

RESULTS

The mean age of the study population was 41.1 ± 14.01 years with a female to male ratio of 7:3. The most frequently reported symptoms and signs were fatigue (60.17%) and weight gain with poor appetite (36.22%). Menstrual abnormalities were reported in all women (n = 730) who had not attained menopause. Grades 1 and 2 goiter (as per the WHO) were observed in 15.41% and 3.27% patients, respectively. Comorbidities were reported in 545 patients (36.36%), type 2 diabetes mellitus being the most prevalent (13.54%) followed by hypertension (11.34%). Total serum thyroxine (T4) and thyroid-stimulating hormone (TSH) levels were assessed in 291 (19.47%) patients only. In majority of patients (81%), treatment was based on serum TSH levels alone. The dose of levothyroxine ranged from 12.5 to 375 mcg.

CONCLUSIONS

Guidelines suggest a diagnosis of hypothyroidism based on TSH and T4 levels. However, most of the patients as observed in this registry received treatment with levothyroxine based on TSH levels alone, thus highlighting the need for awareness and scientific education among clinicians in India. The use of standard doses (100, 75, and 25 mcg) of levothyroxine may point toward empirical management practices.

Cholesterol Synthesis Increased in the MMI-Induced Subclinical Hypothyroidism Mice Model

Subclinical hypothyroidism (SCH) is defined as increased serum thyroid-stimulating hormone (TSH) concentrations and normal serum thyroid hormone (TH) levels as well as an increased serum cholesterol level, which is an important cause of secondary hypercholesterolemia and cardiovascular diseases. Some studies have demonstrated a direct effect of TSH on cholesterol metabolism via in vivo and in vitro experiments. However, because no suitable SCH model has been established until now, the changes in cholesterol synthesis that occur in SCH patients remain unknown. Here, we establish an SCH mouse model by using long-term low-dose MMI administered in drinking water. Compared with the control group, the MMI-treated mice had elevated circulating TSH levels, but the serum FT3 levels in these mice did not change. Additionally, the TC levels increased in both the serum and liver of the experimental mice. Both the protein expression and activity of hepatic HMGCR, the rate-limiting enzyme for cholesterol synthesis in the liver, increased in these mice. We also found that the SCH mice had decreased phospho-HMGCR and phospho-AMPK expression, while the expression of AMPK showed no change. In conclusion, we established a suitable SCH model in which cholesterol synthesis is increased.

Chiropractic Management of a Patient With Chronic Fatigue: A Case Report

OBJECTIVE

The purpose of this case report was to describe the examination and management of a patient with chronic fatigue.

CLINICAL FEATURES

A 34-year-old woman presented to a chiropractic clinic with complaints of fatigue and inability to lose weight for 2 years. When tested, she was found to have high serum thyroglobulin antibodies, low serum vitamin D3, low saliva dehydroepiandrosterone-sulfate, and low saliva total and diurnal cortisol.

INTERVENTION AND OUTCOME

The patient was placed on an anti-inflammatory ancestral diet and given recommendations to decrease the aerobic intensity of her exercise routine. On the basis of the result of conventional and functional laboratory tests, she was prescribed a treatment plan of targeted supplementation. After 12 weeks of application of dietary, lifestyle, and supplementation recommendations, the patient reported experiencing increased energy and weight loss of 15 pounds. Her thyroglobulin antibodies returned within reference range, salivary cortisol increased and closely followed the proper circadian rhythm, and dehydroepiandrosterone-sulfate increased.

CONCLUSIONS

This report describes improvement in a patient with chronic fatigue with the use of nonpharmaceutical polytherapy involving dietary changes, lifestyle modification, and supplementation.

Preservation of renal function by thyroid hormone replacement in elderly persons with subclinical hypothyroidism

INTRODUCTION

The treatment of subclinical hypothyroidism in elderly persons is controversial. Previous studies have shown that there are interactions between kidney and thyroid function, but data regarding interventions that target thyroid function in elderly patients are scarce. We aimed to investigate the impact of thyroid hormone therapy on the estimated glomerular filtration rate (eGFR) in elderly patients.

MATERIAL AND METHODS

Ninety elderly patients aged ≥ 65 years with subclinical hypothyroidism were followed for 36 months in our case-control study. The changes in the eGFR in patients with and without thyroid hormone replacement therapy were compared. The adverse effects during the treatment period were noted.

RESULTS

The eGFR of both groups was similar at the beginning of the study (43.4 ±6.1 vs. 42.8 ±5.9 ml/min/1.73 m(2); p = 0.62). With the decline in thyroid stimulating hormone levels after treatment, the eGFR of the treatment group significantly improved compared with the control group (45.8 ±4.8 vs. 35.8 ±5.3 ml/min/1.73 m(2); p < 0.001); the eGFR increased rapidly over the first 6 months and then plateaued. No patients withdrew from the study, but the therapeutic dose was decreased in two patients due to angina pectoris.

CONCLUSIONS

Thyroid hormone therapy preserved renal function in elderly patients. Appropriate individual treatment should be considered in elderly patients with subclinical hypothyroidism.

Poor glycemic control is associated with the risk of subclinical hypothyroidism in patients with type 2 diabetes mellitus

BACKGROUND/AIMS

Overt hypothyroidism is frequently found in patients with type 2 diabetes mellitus (T2DM), but it remains unknown the relationship between subclinical hypothyroidism (SCH) and T2DM. We attempt to evaluate the difference in prevalence of SCH between patients with T2DM and general population, and the association between SCH and glycemic control status ofdiabetic patients.

METHODS

This was cross-sectional study. Total 8,528 subjects who visited for health check-up were recruited. SCH was defined as an elevated level of serum thyroid stimulating hormone (> 4.0 mIU/L) with a normal level of free thyroxine. T2DM group was categorized into three groups by glycosylated hemoglobin (HbA1c): < 7% (reference), ≥ 7% and < 9%, ≥ 9%.

RESULTS

Finally, 7,966 subjects were included. The prevalence of SCH was not different between healthy controls and subjects with T2DM (8.1% vs. 7.4%, p = 0.533; in men, 5.7% vs. 5.1%, p = 0.573; in women, 10.9% vs. 11.7%, p = 0.712), but it was increased with highest HbA1c group more than well controlled group, especially in women. The risk of SCH was increased by group with poorer glycemic control; the odds ratio for HbA1c ≥ 9% compared to < 7% was 2.52 (95% confidence interval [CI], 1.09 to 5.86; p = 0.031), and 4.58 (95% CI, 1.41 to 14.87; p = 0.011) in women, but not significant in men.

CONCLUSIONS

The prevalence of SCH was similar between T2DM and healthy group. Poor glycemic control in T2DM was obviously associated with the risk of SCH, especially in elderly women. These results suggest SCH as comorbidity may be considered in elderly women with poor glycemic control.

Subclinical Hypothyroidism after 131I-Treatment of Graves' Disease: A Risk Factor for Depression?

Objectives

Although it is well accepted that there is a close relationship between hypothyroidism and depression, previous studies provided inconsistent or even opposite results in whether subclinical hypothyroidism (SCH) increased the risk of depression. One possible reason is that the etiology of SCH in these studies was not clearly distinguished. We therefore investigated the relationship between SCH resulting from ¹³¹I treatment of Graves’ disease and depression.

Design And Methods

The incidence of depression among 95 patients with SCH and 121 euthyroid patients following ¹³¹I treatment of Graves’ disease was studied. The risk factors of depression were determined with multivariate logistic regression analysis. Thyroid hormone replacement therapy was performed in patients with thyroid-stimulating hormone (TSH) levels exceeding 10 mIU/L.

Results

Patients with SCH had significantly higher Hamilton Depression Scale scores, serum TSH and thyroid peroxidase antibody (TPOAb) levels compared with euthyroid patients. Multivariate logistic regression analysis revealed SCH, Graves’ eye syndrome and high serum TPO antibody level as risk factors for depression. L-thyroxine treatment is beneficial for SCH patients with serum TSH levels exceeding 10 mIU/L.

Conclusions

The results of the present study demonstrated that SCH is prevalent among ¹³¹I treated Graves’ patients. SCH might increase the risk of developing depression. L-thyroxine replacement therapy helps to resolve depressive disorders in SCH patients with TSH > 10mIU/L. These data provide insight into the relationship between SCH and depression.

A high thyroid stimulating hormone level is associated with diabetic peripheral neuropathy in type 2 diabetes patients

AIM

The association between thyroid stimulating hormone (TSH) and type 2 diabetes mellitus (T2DM) is well known. However, whether TSH is related to diabetic peripheral neuropathy (DPN) has not been studied. The aim of this study was to explore the relationship between TSH and DPN in Chinese patients with T2DM.

METHODS

In this cross-sectional study, 605 patients with T2DM were enrolled. Subclinical hypothyroidism (SCH) was defined as an elevated TSH level (>4.0mIU/L) and a normal free thyroxine level. DPN was evaluated by neurological symptoms, neurological signs, and electromyogram.

RESULTS

Serum TSH levels were significantly higher in DPN and signs of DPN compared with non-DPN T2DM patients (both P<0.01).The prevalence of DPN and signs of DPN in SCH subjects was higher than that in euthyroid subjects (both P<0.01). Spearman's correlation analysis showed that the serum TSH level was positively associated with DPN (r=0.172, P<0.01). A significant independent association between TSH and DPN was found by multiple logistic regression analysis after adjusting for potential confounding variables [odds ratio (OR)=1.365, P<0.01]. The patients were sequentially assigned to quartiles according to TSH level. Compared with quartile 1, patients in quartile 2 (P<0.01), quartile 3 (P=0.01), and quartile 4 (P<0.01) had a higher risk of DPN. Receiver-operating characteristic curve analysis revealed that the optimal cutoff point of TSH to indicate DPN was 3.045mIU/L in men and 2.94mIU/L in women.

CONCLUSION

TSH level is independently associated with DPN in Chinese population with T2DM. A high serum TSH level may be a potential risk factor for DPN.

Pediatric Goiter: Can Thyroid Disorders Be Predicted at Diagnosis and in Follow-Up?

OBJECTIVE

To investigate the prevalence of thyroid dysfunction, autoimmune thyroid disease (AITD), and simple goiter at goiter diagnosis, and to analyze the natural course of simple goiter and predictors for progression to AITD and/or thyroid dysfunction.

STUDY DESIGN

In total, 939 patients (770 females, 5.0-17.9 years) with goiter were reviewed retrospectively. Anthropometrics, pubertal status, goiter grade, and family history (FH) of thyroid disease were investigated. Simple goiter was defined as euthyroid goiter without pathologic cause, after excluding AITD and isolated nonautoimmune hyperthyrotropinemia (iso-NAHT).

RESULTS

At diagnosis, 36.9% of children showed thyroid dysfunction and/or AITD (euthyroid AITD [9.9%], hyper- or hypothyroid AITD [18.4%], iso-NAHT [8.6%]). Risk for subsequent medication was higher in euthyroid AITD than simple goiter (20.4% vs 0.3%, P < .001). Hashimoto thyroiditis (HT) and iso-NAHT developed in 5.2% and 6.6% of patients initially diagnosed with simple goiter during the median 2.0-year follow-up. Compared with the persistent simple goiter group, the HT group had greater FH (54.8% vs 23.6%) and unchanged or increasing goiter size (89.3% vs 71.8%), and the iso-NAHT group had a higher proportion of patients within the upper tertile range of baseline thyrotropin levels (71.8% vs 24.9%) and unchanged or increasing goiter size (86.8% vs 71.8%; all P < .05).

CONCLUSIONS

Thyroid disorders were detected in one-third of pediatric patients presenting with goiter. The higher risk for thyroid dysfunction needing medication in patients with euthyroid AITD emphasizes the importance of autoantibody evaluation at diagnosis. During simple goiter follow-up, progression to HT or iso-NAHT occurs, especially in patients with FH or persistent goiter.

Clinical outcomes of patients with hypothyroidism undergoing percutaneous coronary intervention

AIMS

The aim of this study was to investigate the association between hypothyroidism and major adverse cardiovascular and cerebral events (MACCE) in patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Two thousand four hundred and thirty patients who underwent PCI were included. Subjects were divided into two groups: hypothyroidism (n = 686) defined either as a history of hypothyroidism or thyroid-stimulating hormone (TSH) ≥5.0 mU/mL, and euthyroidism (n = 1744) defined as no history of hypothyroidism and/or 0.3 mU/mL ≤ TSH < 5.0 mU/mL. Patients with hypothyroidism were further categorized as untreated (n = 193), or those taking thyroid replacement therapy (TRT) with adequate replacement (0.3 mU/mL ≤ TSH < 5.0 mU/mL, n = 175) or inadequate replacement (TSH ≥ 5.0 mU/mL, n = 318). Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. Median follow-up was 3.0 years (interquartile range, 0.5-7.0). After adjustment for covariates, the risk of MACCE and its constituent parts was higher in patients with hypothyroidism compared with those with euthyroidism (MACCE: HR: 1.28, P = 0.0001; myocardial infarction (MI): HR: 1.25, P = 0.037; heart failure: HR: 1.46, P = 0.004; revascularization: HR: 1.26, P = 0.0008; stroke: HR: 1.62, P = 0.04). Compared with untreated patients or those with inadequate replacement, adequately treated hypothyroid patients had a lower risk of MACCE (HR: 0.69, P = 0.005; HR: 0.78, P = 0.045), cardiac death (HR: 0.43, P = 0.008), MI (HR: 0.50, P = 0.0004; HR: 0.60, P = 0.02), and heart failure (HR: 0.50, P = 0.02; HR: 0.52, P = 0.017).

CONCLUSION

Hypothyroidism is associated with a higher incidence of MACCE compared with euthyroidism in patients undergoing PCI. Maintaining adequate control on TRT is beneficial in preventing MACCE.

Evaluation of Subclinical Hypothyroidism in Children and Adolescents: A Single-Center Study

The main purpose of our retrospective study was to evaluate the medical care of the patients with subclinical hypothyroidism (sHT) and to investigate the rationale for administering L-thyroxine (LT-4) to young sHT patients. Patients and Methods. Based on a retrospective review of the charts of 261 patients referred to the Endocrinology Outpatient Clinic between 2009 and 2014 with suspicion of sHT, 55 patients were enrolled for further analysis. Data collected was baseline age, anthropometric measurements, serum TSH, fT4, fT3, anti-thyroid autoantibodies, positive family history, absence/presence of clinical symptoms, length of follow-up, and data concerning LT-4 therapy (therapy: T1; no therapy: T0). Results. T1 encompassed 33 (60.0%) patients. There were no differences between T1 and T0 (p > 0.05) with regard to age, TSH concentrations, BMI Z-score, and hSDS values, though follow-up was longer in T1 (p < 0.01). Four (11.8%) children in T1 and none in T0 had a positive family history of thyroid disorders. Fifteen (68.2%) patients in group T0 became euthyroid. One (1.8%) girl (T1) developed overt hypothyroidism. Conclusions. A small percentage of patients can proceed to overt hypothyroidism. Only positive family history seemed to influence the decision to initiate LT-4 therapy. Further prospective studies are warranted in order to establish treatment indications, if any, and the mean recommended dosage of LT-4.

Cardiovascular Risk Factors in Subclinical Hypothyroidism: A Case Control Study in Nepalese Population

Objectives. To assess cardiovascular risk factors in Nepalese population with subclinical hypothyroidism as compared to age and sex matched controls. Materials and Methods. A case control study was conducted among 200 subjects (100 subclinical hypothyroid and 100 euthyroid) at B.P. Koirala Institute of Health Sciences, Dharan, Nepal. Demographic and anthropometric variables including systolic and diastolic blood pressure (BP) were taken. Blood samples were assayed for serum free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and high sensitivity C reactive protein (hs-CRP). Results. Subclinical hypothyroid patients had significantly higher diastolic BP, total cholesterol, LDL cholesterol, and hs-CRP than controls. The odds ratio of having hypercholesterolemia (>200 mg/dL), low HDL cholesterol (<40 mg/dL), undesirable LDL-cholesterol (>100 mg/dL), high hs-CRP (>1 mg/L), and high diastolic BP (>80 mmHg) and being overweight (BMI ≥ 23 Kg/m²) in subclinical hypothyroidism was 2.29 (95% CI; 1.2–4.38, p = 0.011), 1.73 (95% CI; 0.82–3.62, p = 0.141), 3.04 (95% CI; 1.66–5.56, p < 0.001), 2.02 (95% CI; 1.12–3.64, p = 0.018), 3.35 (95% CI; 1.72–6.55, p < 0.001), and 0.9 (95% CI; 0.48–1.67, p = 0.753), respectively, as compared to controls. Conclusion. Subclinical hypothyroid patients are associated with higher risk for cardiovascular disease than euthyroid subjects.

Subclinical hypothyroidism and the associations with macrovascular complications and chronic kidney disease in patients with Type 2 diabetes

AIMS

The prevalence of subclinical hypothyroidism (SCH) is high among patients with diabetes, although the relationship between SCH and diabetic vascular complications is unknown. This study aimed to determine the relationship between SCH and vascular complications in patients with Type 2 diabetes.

METHODS

In this cross sectional study, 991 patients with Type 2 diabetes were screened for thyroid function at their admission to the Second Affiliated Hospital of Chongqing Medical University. We compared the prevalence of coronary heart disease (CHD), ischaemic stroke and chronic kidney disease (CKD) with the prevalence of euthyroidism and SCH.

RESULTS

Among the 991 patients, 126 (12.7%) patients had SCH. The prevalence of CHD was significantly higher in the SCH group than in the euthyroid group (22.2% and 15.0%, respectively; P = 0.039). In the logistic regression analyses, SCH was associated with CHD [odds ratio (OR): 1.993; 95% confidence interval (CI): 1.135-3.497; P = 0.016]. This association was stronger in patients aged ≥ 65 years than in younger patients [2.474 (1.173-5.220); P = 0.017]. No significant association was found between SCH and ischaemic stroke. Patients with severe SCH had a high risk of CKD [1.842 (1.120-3.029); P = 0.016].

CONCLUSIONS

This study provides evidence that SCH in patients with Type 2 diabetes is associated with a high prevalence of CHD (and CKD in severe SCH), although not with ischaemic stroke.

Relationship between Diabetic Retinopathy and Subclinical Hypothyroidism: a meta-analysis

Several epidemiological studies have found a positive association between diabetic retinopathy (DR) and subclinical hypothyroidism (SCH), but the findings are varied or even contradictory. In the work, we performed a meta-analysis to ascertain the relationship between DR and SCH. We searched relevant studies on the relationship between DR and SCH. All English reports were used Medline, EMbase, Web of Science, Google scholar, and all Chinese ones used CBMDisc (Chinese Biochemical Literature on Disc) and CNKI (China National Knowledge Infrastructure) database. Meta-analysis was performed using RevMan 5.1 software. We obtained eight observational studies. Random-effects meta-analysis indicated a significant association between DR and SCH (odds ratio = 2.13, 95% confidence interval = 1.41 – 3.23, p < 0.001). Based on currently evidence, SCH is probably a significant risk factor for DR.

Comparison of pre- and post-levothyroxine high-sensitivity c-reactive protein and fetuin-a levels in subclinical hypothyroidism

OBJECTIVE

The objective of this trial was to determine the levels of inflammatory markers, high-sensitivity C-reactive protein and fetuin-A pre- and post-levothyroxine treatment in cases of subclinical hypothyroidism.

MATERIALS AND METHODS

A total of 32 patients with a diagnosis of subclinical hypothyroidism and a control group of 30 healthy individuals were tested for high-sensitivity C-reactive protein and fetuin-A, followed by the administration of 50 µg of levothyroxine in the patient group for 3 months. During the post-treatment stage, high-sensitivity C-reactive protein and fetuin-A levels in the patient group were re-assessed and compared with pre-treatment values.

RESULTS

Pre-treatment levels of both high-sensitivity C-reactive protein and fetuin-A were observed to be higher in the patient group than in the control group. The decrease in high-sensitivity C-reactive protein levels during the post-treatment stage was not statistically significant. However, the decrease observed in post-treatment fetuin-A levels was found to be statistically significant.

CONCLUSION

The decrease in fetuin-A levels in subclinical hypothyroidism cases indicates that levothyroxine treatment exerts anti-inflammatory and anti-apoptotic effects. Although the decrease in high-sensitivity C-reactive protein levels was statistically non-significant, it is predicted to reach significance with sustained treatment.