Well-being, health-related quality of life and cardiovascular disease risk profile in women with subclinical thyroid disease - a community-based study

The enigma of persistent symptoms in hypothyroid patients treated with levothyroxine: A narrative review

A significant minority of patients with hypothyroidism report persistent symptoms despite achieving normal thyroid biochemistry after levothyroxine (L-T4) replacement. Four principal lines of thinking, which are not mutually exclusive, may explain this enigma. The 'low tissue liothyronine hypothesis' emphasizes the potential imperfections of L-T4 replacement therapy that may lead to hypothyroidism in some tissues such as the brain, while others (eg hypothalamus) are euthyroid. The 'Somatic Symptom and Related Disorders hypothesis' draws attention to an incidental coexistence of a diagnosis of Somatic Symptom and Related Disorders in patients with treated hypothyroidism. The 'autoimmune neuroinflammation hypothesis' highlights the potential consequences of inflammatory mediators due to thyroid autoimmunity (the commonest cause of hypothyroidism) on the brain. The 'comorbidities and psychosocial hypothesis' implicates a variety of physical and psychosocial factors that have been noted to be associated with a diagnosis of hypothyroidism, which may be primarily the cause of persistent complaints. Over the past twenty years, a great deal of time and effort has been expended pursuing the 'low tissue liothyronine hypothesis', which has failed to yield results that translate to patient benefits. This has skewed the balance in clinical practice, in favour of pursuing answers relating to L-T4 and liothyronine combination treatment, while the alternative explanations have been downplayed and potentially useful interventions have been given insufficient attention.

Hypothyroidism and Diabetes-Related Dementia: Focused on Neuronal Dysfunction, Insulin Resistance, and Dyslipidemia

The incidence of dementia is steadily increasing worldwide. The risk factors for dementia are diverse, and include genetic background, environmental factors, sex differences, and vascular abnormalities. Among the subtypes of dementia, diabetes-related dementia is emerging as a complex type of dementia related to metabolic imbalance, due to the increase in the number of patients with metabolic syndrome and dementia worldwide. Thyroid hormones are considered metabolic regulatory hormones and affect various diseases, such as liver failure, obesity, and dementia. Thyroid dysregulation affects various cellular mechanisms and is linked to multiple disease pathologies. In particular, hypothyroidism is considered a critical cause for various neurological problems-such as metabolic disease, depressive symptoms, and dementia-in the central nervous system. Recent studies have demonstrated the relationship between hypothyroidism and brain insulin resistance and dyslipidemia, leading to diabetes-related dementia. Therefore, we reviewed the relationship between hypothyroidism and diabetes-related dementia, with a focus on major features of diabetes-related dementia such as insulin resistance, neuronal dysfunction, and dyslipidemia.

Lipid profile in mild subclinical hypothyroidism: systematic review and meta-analysis

INTRODUCTION

Only severe subclinical hypothyroidism (SSCH) with TSH above 10 mIU/L is considered a risk factor of hyperlipidemia and cardiovascular disease. The results of published papers on mild subclinical hypothyroidism (MSCH) with TSH below10 mIU/L are contradictory. The objective of the study was to conduct a systematic review and meta-analysis on lipid profiles in a population of patients with MSCH (TSH10> mIU/L and normal T3, T4) in comparison with euthyroid subjects.

EVIDENCE ACQUISITION

The electronic databases PubMed, CIANHL, Scopus, and Web of Science were searched systematically between August 20, 2018 and September 15, 2018, without limitation on the date of publication or the language. Titles, abstracts and articles were reviewed to identify papers that evaluated lipid profiles in patients with MSCH compared to euthyroid.

EVIDENCE SYNTHESIS

A systematic review of the studies and a meta-analysis using R software (version 3.6.1) were performed. Thirty-five case control and cohort studies were included in the meta-analysis. Total cholesterol (TC), low density lipoprotein (LDL), and triglycerides (TG) were significantly higher and high-density lipoprotein (HDL) was significantly lower in MSCH patients compared to euthyroid individuals. Mean differences (MD) [95% CI] were 12.75 [6.02, 19.48], 10.95 [6.37, 15.54], 19.27 [10.90, 27.64], and -1.81 [-3.38, -0.23], respectively. No significant difference was observed for very low-density lipoproteins (VLDL), apolipoprotein A1 (apoA1), or apolipoprotein B (apoB). The studies were of fair to good quality.

CONCLUSIONS

MSCH is associated with an increase in major atherogenic lipoproteins and should be viewed as a cardiovascular risk factor.

Menopausal Impact on the Association Between Thyroid Dysfunction and Lipid Profiles: A Cross-Sectional Study

BACKGROUND

Both dyslipidemia and thyroid dysfunction have a high prevalence rate and are important risk factors for cardiovascular diseases. However, the relationship between blood lipids and thyroid dysfunction is still controversial. This study aims to analyze the blood lipids in people with different thyroid functions.

METHODS

A total of 80937 adults were included in this population-based cross-sectional TIDE survey, which collected demographic and clinical data on thyroid function, blood lipid levels and other metabolic indicators. After screening, the final analysis included 10,747 participants, who were divided into hypothyroidism (n=311), subclinical hypothyroidism (n=5015), hyperthyroidism (n=203), subclinical hyperthyroidism (n=118) and control (n=5100) groups. The risk of dyslipidemia was analyzed by a logistic regression model and divided into groups of female menopausal.

RESULTS

After full adjustment, significant associations were found between hypothyroidism and hypertriglyceridemia. Subclinical hypothyroidism was associated with a significantly higher risk of hypertriglyceridemia and hyper-low density lipoprotein cholesterolemia. Hyperthyroidism was significantly correlated with a reduced risk of hypercholesterolemia and hyper-low density lipoprotein cholesterolemia but positively correlated with the risk of low-high density lipoprotein cholesterolemia. There was no significant association between subclinical hyperthyroidism and blood lipids. Hypothyroidism increased the risk of hypertriglyceridemia in both premenopausal and postmenopausal females. Subclinical hypothyroidism was significantly associated with increased hypertriglyceridemia and low-high density lipoprotein cholesterolemia in premenopausal females. Hyperthyroidism was significantly associated with a reduced risk of hypercholesterolemia and hyper-low density lipoprotein cholesterolemia in premenopausal females and an increased risk of low-high density lipoprotein cholesterolemia in postmenopausal female.

CONCLUSION

Abnormal thyroid function has an important effect on blood lipids and is closely related to female menopause.

A longitudinal population-based study of progression rates for borderline TSH abnormalities

CONTEXT

Current guidelines recommend TSH for initial biochemical evaluation of thyroid function, with borderline TSH abnormalities a common finding. The likelihood of a borderline TSH progressing to overt abnormality is not well characterised at the population level.

OBJECTIVE

To determine risk factors and likelihood for progression of borderline TSH to overt abnormality.

DESIGN, SETTING, PARTICIPANTS, & INTERVENTION

Population-based retrospective longitudinal data-linkage study for TSH tests performed in Tasmania (1996-2013). Kaplan-Meier methodology was used to summarise conversion time for overt TSH elevation (≥10mU/L) and overt suppression (≤0.1mU/L) in patients whose initial TSH was borderline elevated (BeTSH) (4.0-9.99mU/L) and borderline suppressed (BsTSH) (0.10-0.39mU/L) respectively.

MAIN OUTCOME MEASURES

Progression from borderline to overt TSH abnormality.

RESULTS

A total of 1,296,060 TSH tests were performed on 367,917 patients. Of these, 14,507 (3.9%) patients had BeTSH on initial assessment; mean age 51.4±21.8 years and median TSH of 5.0mU/L (IQR 4.4, 5.2). Patients aged ≥80 years were most likely to progress (HR=2.09 compared to age ≤20 years reference group [95% CI: 1.64, 2.68]). Patients aged 20-39 years had the second highest rate of progression (HR=1.49 [95% CI: 1.18, 1.88]). 7,883 (2.14%) patients had BsTSH; mean age 50.7±22.1 years and median TSH 0.30mU/L (IQR 0.22, 0.35). Patients aged 60-79 years had the highest rate of progression to overt TSH suppression (HR = 2.47 compared to age ≤20 years reference group [95% CI: 1.88, 3.22]).

CONCLUSIONS

Follow-up intervals for patients with borderline TSH abnormalities should take into account patient age as a progression risk factor. This article is protected by copyright. All rights reserved.

The impact of subclinical hypothyroidism on health-related quality of life: a narrative review

A biochemical diagnosis of subclinical hypothyroidism is defined by an elevated serum thyroid-stimulating hormone (TSH) with a normal serum free thyroxine (FT4). This paper discusses SCH in the Australian population, the impact of SCH on health-related quality of life (HRQoL), and the evidence for thyroid hormone therapy as well as exercise therapy to improve HRQoL in SCH. The prevalence of SCH in Australia is approximately 4-5% and is higher in females and the elderly. Current evidence suggests thyroid hormone therapy is not associated with an improvement in HRQoL. However, there does appear to be a subgroup of those with SCH that experience an impairment in HRQoL who may potentially benefit from treatment. Because the majority of research to date has been done in elderly, largely asymptomatic individuals, this may not be representative of the entire SCH population. Additionally, alternative treatments such as exercise therapy have not been well explored in the literature, despite exercise therapy's effects on HRQoL in other populations. Further research is required to clearly define which individuals with SCH are likely to experience an impaired HRQoL, as well as explore the effects of thyroid hormone therapy and exercise therapy in these individuals. This article is protected by copyright. All rights reserved.

Alexithymia, Emotional Distress, and Perceived Quality of Life in Patients With Hashimoto's Thyroiditis

Emotion-processing impairment represents a risk factor for the development of somatic illness, affecting negatively both health-related quality of life (HRQoL) and disease management in several chronic diseases. The present pilot study aims at (i) investigating the associations between alexithymia and depression, anxiety, and HRQoL in patients with Hashimoto's thyroiditis (HT); (ii) examining the association between these three psychological conditions together with HRQoL, and thyroid autoantibodies status as well as thyroid echotexture in patients with HT; and (iii) comparing the intensity of all these clinical psychological features in patients with HT versus controls. Twenty-one patients with serologically or ultrasonographically verified HT and 16 controls with non-toxic goiter or postsurgical hypothyroidism were recruited for this study. Serum thyrotropin (TSH) and free thyroxine, as well as thyroid autoantibodies (thyroglobulin antibodies and thyroid peroxidase antibodies), were assayed. Alexithymia, depression, anxiety, and HRQoL were assessed with Toronto Alexithymia Scale; Beck Depression Inventory, second edition; Hamilton Anxiety Rating Scale; and Health Survey Short-Form 36, respectively. A negative relationship between the difficulty to describe feelings and the cognitive component of depression was found (r = -0.46, p = 0.04). Besides, patients with seronegative HT had lower somatic anxiety than patients with HT who tested positive (r = -0.68, p = 0.01 and r = -0.59, p = 0.04, respectively). Besides, no statistically significant difference was found between patients with HT and controls with regard to somatic anxiety. The present study suggests the relevance of alexithymia in patients suffering from HT, which may be intertwined with a possible state of underreported depression that is mainly expressed through physical complaints. Promoting the capability to describe and communicate feelings could contribute to psychological elaboration and coping with the disease and, consequently, to the improvement of self-management and perceived HRQoL.

The relation between thyroid dysregulation and impaired cognition/behaviour: An integrative review

Despite decades of research on the relation between thyroid diseases and cognition, the nature of this relationship remains elusive. An increasing prevalence of cognitive impairment and thyroid dysfunction has been consistently observed with ageing. Also, there appears to be an association between thyroid disorders and cognitive decline. Given the increasing global burden of dementia, elucidating the relationship between thyroid disorders as a potentially modifiable risk factor of cognitive impairment was the main goal of this review. We summarise the current literature examining the relationship between thyroid hormonal dysregulation and cognition or behaviour. We present the available imaging and pathological findings related to structural and functional brain changes related to thyroid hormonal dysregulation. We also propose potential mechanisms of interaction between thyroid hormones, autoantibodies and cognition/behaviour. Effects of gender, ethnicity and environmental factors are also briefly discussed. This review highlights the need for long-term prospective studies to capture the course of brain functional changes associated with the incidence and progression of thyroid dysregulations along with the confounding effects of non-modifiable risk factors such as gender and ethnicity. Moreover, double-blind controlled clinical trials are necessary to devise appropriate treatment plans to prevent cognitive consequences of over or undertreatment of thyroid disorders.

Subclinical Thyroid Dysfunction and the Risk of Cardiovascular Disease

The prevalence of subclinical hypothyroidism (SH) is 3-10%. The prevalence of subclinical hyperthyroidism (SHr) is 0.7-9.7%. Thyroid hormones affect cardiac electrophysiology, contractility, and vasculature. SH is associated with an increased risk of coronary heart disease (CHD), especially in subjects under 65. SHr seems to be associated with a slightly increased risk of CHD and an increase in CHD-related mortality. Both SH and SHr carry an increased risk of developing heart failure (HF), especially in those under 65. Both SH and SHr are associated with worse prognoses in patients with existing HF. SH is probably not associated with atrial fibrillation (AF). SHr, low normal thyroid-stimulating hormone (TSH) and high normal free thyroxine (FT4) are all associated with the increased risk of AF. An association between endothelial dysfunction and SH seems to exist. Data regarding the influence of SHr on the peripheral vascular system are conflicting. SH is a risk factor for stroke in subjects under 65. SHr does not increase the risk of stroke. Both SH and SHr have an unfavourable effect on cardiovascular disease (CVD) and all-cause mortality. There is a U-shaped curve of mortality in relation to TSH concentrations. A major factor that modifies the relation between subclinical thyroid disease (SCTD) and mortality is age. SH increases blood pressure (BP). SHr has no significant effect on BP. Lipids are increased in patients with SH. In SHr, high-density lipoprotein cholesterol and lipoprotein( a) are increased. SCTD should be treated when TSH is over 10 mU/l or under 0.1 mU/l. Treatment indications are less clear when TSH is between normal limits and 0.1 or 10 mU/L. The current state of knowledge supports the understanding of SCTD's role as a risk factor for CVD development. Age is a significant confounding factor, probably due to age-associated changes in the TSH reference levels.

Subclinical Hypothyroidism and Associated Cardiovascular Risk Factor in Perimenopausal Females

Background

Perimenopause refers to the period around menopause (40-55 years). This includes the period before menopause and the first year after menopause. Perimenopausal age is an important stage in a women's life. Many women are diagnosed with hypothyroidism at midlife. Hypothyroidism - both overt and subclinical are associated with increased risk of CVS diseases. Subclinical hypothyroidism is more important as this stage is usually ignored from treatment point of view and if early intervention is done in SCH worsening of metabolic derangement may be avoided.

Objectives

The present study was aimed to know the prevalence of subclinical hypothyroidism and associated dyslipidemia in perimenopausal females.

Material and Methods

In our retrospective study we took 100 perimenopausal females (40-55years) who were investigated for thyroid and lipid profile. Atherogenic indices like TC/HDL-c, LDL-c/HDL-c, TG/HDL-c ratios were calculated from the individual lipid profile parameters. The reference guidelines for lipid profile was according to NCEP ATP III.

Result

Subclinical hypothyroidism was found to be present in 18% of perimenopausal females The mean TSH levels were found to be higher in SCH as compared to euthyroid females with a mean value of 7.56±3.54(μIU/ ml). Dyslipidemia was seen in patients with SCH. TSH levels were found to be positively correlated with total cholesterol.

Conclusion

We conclude that subclinical hypothyroidism is present in 18% females of perimenopausal age group. Increased TSH levels are associated with hypertension, hypertriglyceridemia, and elevated TC/HDL-C ratio and non cholesterol HDL. In perimenopausal women the condition is usually underdiagnosed and ignored but subclinical hypothyroidism in these females should be screened and treated timely to decrease the risk of accelerated atherosclerosis and premature coronary artery disease in them.

The Association Between Prolactin and Metabolic Parameters in PCOS Women: A Retrospective Analysis

Background: The aim of this retrospective study was to analyze the association between prolactin (PRL) and metabolic parameters in infertile patients with polycystic ovary syndrome (PCOS). Methods: A total of 2,052 patients with PCOS and 9,696 patients with tubal infertility (non-PCOS) undergoing in vitro fertilization and embryo transfer (IVF-ET) at the reproductive medicine center of the first affiliated hospital of Wenzhou Medical University from January 2007 to July 2017 were enrolled in this study. Serum PRL, basic endocrine hormones, fasting plasma lipid, fasting plasma glucose (FPG), liver function, thyroid hormone and other parameters were measured and analyzed. Result: PRL levels were significantly lower in PCOS patients than controls over all age groups (p < 0.05). In the PCOS patients, serum PRL was significantly and positively correlated with FPG, serum TSH and serum FT4, and significantly and negatively correlated with LH, LH/FSH, TC, TG, LDL-C, AST, ALT, γ-GGT, FT3, and FT3/FT4 (p < 0.05 or 0.01). After adjusted for age and body mass index (BMI), serum PRL was positively correlated with FPG, TSH, and FT4, and negatively correlated with LH and LH/FSH. Conclusion: Low serum PRL may be an important cause of metabolic risk in infertile patients with PCOS.

No Effect of Thyroid Dysfunction and Autoimmunity on Health-Related Quality of Life and Mental Health in Children and Adolescents: Results From a Nationwide Cross-Sectional Study

Background: In adults, a significant impact of thyroid dysfunction and autoimmunity on health-related quality of life (HRQoL) and mental health is described. However, studies in children and adolescents are sparse, underpowered, and findings are ambiguous. Methods: Data from 759 German children and adolescents affected by thyroid disease [subclinical hypothyroidism: 331; subclinical hyperthyroidism: 276; overt hypothyroidism: 20; overt hyperthyroidism: 28; Hashimoto's thyroiditis (HT): 68; thyroid-peroxidase antibody (TPO)-AB positivity without apparent thyroid dysfunction: 61] and 7,293 healthy controls from a nationwide cross-sectional study ("The German Health Interview and Examination Survey for Children and Adolescents") were available. Self-assessed HRQoL (KINDL-R) and mental health (SDQ) were compared for each subgroup with healthy controls by analysis of covariance considering questionnaire-specific confounding factors. Thyroid parameters (TSH, fT4, fT3, TPO-AB levels, thyroid volume as well as urinary iodine excretion) were correlated with KINDL-R and SDQ scores employing multiple regression, likewise accounting for confounding factors. Results: The subsample of participants affected by overt hypothyroidism evidenced impaired mental health in comparison to healthy controls, but SDQ scores were within the normal range of normative data. Moreover, in no other subgroup, HRQoL or mental health were affected by thyroid disorders. Also, there was neither a significant relationship between any single biochemical parameter of thyroid function and HRQoL or mental health, nor did the combined thyroid parameters account for a significant proportion of variance in either outcome measure. Importantly, the present study was sufficiently powered to identify even small effects in children and adolescents affected by HT, subclinical hypothyroidism, and hyperthyroidism. Conclusions: In contrast to findings in adults, and especially in HT, there was no significant impairment of HRQoL or mental health in children and adolescents from the general pediatric population affected by thyroid disease. Moreover, mechanisms proposed to explain impaired mental health in thyroid dysfunction in adults do not pertain to children and adolescents in the present study.

Screening for thyroid dysfunction and treatment of screen-detected thyroid dysfunction in asymptomatic, community-dwelling adults: a systematic review

BACKGROUND

This systematic review was conducted to inform the Canadian Task Force on Preventive Health Care recommendations on screening for thyroid dysfunction (TD). The review sought to answer key questions on the benefits and harms of screening for TD, patients' values and preferences for screening, and the benefits and harms of treating screen-detected TD.

METHODS

This review followed Canadian Task Force on Preventive Health Care methods, which include the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The search strategy used for benefits and harms of screening and treatment was an update to the 2014 review by the US Preventive Services Task Force and searched MEDLINE and the Cochrane Library. MEDLINE, Embase, ProQuest Public Health, and SCOPUS were searched for patients' values and preferences for screening. Outcomes of interest included all-cause mortality, deaths due to cardiovascular diseases, fatal and non-fatal cardiovascular events, atrial fibrillation, fractures, quality of life, cognitive function, and harms due to TD treatment. Two reviewers independently screened abstracts and full texts according to pre-determined inclusion criteria and assessed the risk of bias for each study included. Strength and quality of the evidence was assessed for each outcome. A narrative synthesis was conducted due to heterogeneity of the included studies.

RESULTS

No studies were found on screening for TD, treatment of subclinical hyperthyroidism, or patients' values and preferences for screening for TD. Twenty-two studies (from 24 publications) on the treatment of TD in patients with screen-detected subclinical hypothyroidism were included. Results from the included randomized controlled trials suggested no benefit of treatment for subclinical hypothyroidism for the large majority of outcomes. We found very low-quality evidence (from two cohort studies) for a small reduction in all-cause mortality among adults < 65 or 40-70 years who were treated for TD compared to those who were not.

CONCLUSIONS

This review found moderate to very low-quality evidence on the benefits and harms of treatment for subclinical hypothyroidism, with most of the evidence showing no benefit of treatment.

FABP4 levels in hypothyroidism and its relationship with subclinical atherosclerosis

Background/aim

The aim of this study is to evaluate the relationship between serum fatty acid binding protein 4 (FABP4) levels and carotid intima media thickness (CIMT) in patients with hypothyroidism.

Materials and methods

Forty subclinical hypothyroidism patients, 40 overt hypothyroidism patients, and 40 healthy controls were enrolled in the study. Blood pressure, body mass index, CIMT, fasting blood sugar, creatine, alanine aminotransferase, lipid parameters, insulin, free thyroxine, triiodothyronine, thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), high-sensitivity C-reactive protein (Hs-CRP), and FABP4 levels of all participants were measured.

Results

Serum FABP4 levels were significantly higher in patients with subclinical and overt hypothyroidism than healthy controls (HCs) (P = 0.044 and P = 0.014, respectively). There was no significant difference in terms of FABP4 levels between patients with subclinical and overt hypothyroidism (P = 0.641). Serum TSH levels and serum FABP4 levels were positively correlated (r = 0.201, P = 0.039). CIMT was found to be higher in patients with subclinical and overt hypothyroidism than in HCs (P = 0.042 and P < 0.001, respectively). No correlation was found between CIMT and FABP4 levels (r = 0.038, P = 0.702). There was a positive correlation between CIMT and TSH, anti-TPO, anti-TG, triglycerides (TG), and total cholesterol levels. It was found that high TG levels were an independent factor that increased CIMT (r = 0.382, r2 = 0.146).

Conclusion

In patients with subclinical and overt hypothyroidism, the level of FABP4 increases and this increase is correlated with the increase in TSH level. It is thought that FABP4 does not play a role in atherosclerosis development in patients with hypothyroidism without metabolic disorder.

High Normal Range of Free Thyroxine is Associated with Decreased Triglycerides and with Increased High-Density Lipoprotein Cholesterol Based on Population Representative Data

Background: We aimed to evaluate the association between thyroid hormone (free thyroxine, free T4) level and lipid profiles in nationally representative data. Methods: This study was based on cross-sectional survey data from the sixth Korea National Health and Nutrition Examination Survey IV. After exclusion of subjects with a history of thyroid disease or abnormal thyroid function test and those on medication for dyslipidemia and/or cardiovascular disease, a total of 3548 subjects were included in the study. Results: There was a significant decrease in serum triglyceride levels and increase in serum high-density lipoprotein (HDL) cholesterol levels with high free T4 quartiles after adjustment for confounding factors (p for trend = 0.001 and p for trend = 0.014, respectively). Risk of hypertriglyceridemia was significantly decreased (odds ratio of 0.72 (95% confidential interval 0.53-0.98)) in the highest free T4 quartile compared to the lowest free T4 quartile, p = 0.044). Conclusions: Serum free T4 levels within normal range negatively correlated with serum triglyceride level and positively correlated with HDL-cholesterol level. Therefore, a close surveillance in terms of lipid profiles could be considered in subjects with low normal serum free T4 levels.

Trend of lipid and thyroid function tests in adults without overt thyroid diseases: A cohort from Tehran thyroid study

CONTEXT

While the role of overt hypothyroidism in lipid disorders is clear, the association between dyslipidemia and subclinical thyroid diseases remains unclarified.

OBJECTIVE

To examine lipid trends based on thyroid function over a 10-year period.

DESIGN

This is a prospective population based cohort study.

SETTING

General community.

PARTICIPANTS

2383 euthyroid participants, as well as those with subclinical thyroid diseases, in all residents of district 13 of Tehran were examined. Subjects who were on levothyroxine, anti-hyperthyroid drugs, and glucocorticoids, those with a history of thyroid surgery or RAI and pregnant women were excluded.

MAIN OUTCOME MEASURES

Lipid trends in Model 1 were adjusted for age and follow up duration, and in Model 2 gender-specific multivariate adjustments were performed for thyroid status, diabetes mellitus, smoking status, education, BMI, lipid lowering medications, age and follow up duration by using generalized estimating equations.

RESULTS

In every four years of assessments, there were significant decreases in levels of all lipid parameters (all Ps <0.001) except for HDL-C, in which a decrescendo-crescendo trend was observed. The results did not change after adjusting for thyroid status, consumption of lipid lowering drugs during the follow-up period, or other variables. There were significant decreases in the prevalence of hypercholesterolemia and hypertriglyceridemia (all Ps <0.001) during the follow-up period.

CONCLUSION

During a 10 year follow-up, decrescendo trends were observed in levels of total cholesterol, triglycerides, which were not be accounted for by the consumption of lipid lowering drugs and thyroid status.

Low fT3 is associated with diminished health-related quality of life in patients with acute coronary syndrome treated with drug-eluting stent: a longitudinal observational study

Acute coronary syndrome (ACS) patients with low triiodothyronine (T3) syndrome characterized by low free T3 (fT3) levels with normal thyroxine (T4) and thyroid-stimulating hormone (TSH) have a higher rate of death. The impact of fT3 on Health related quality of life (HRQOL) in patients with ACS is still unknown. 528 ACS patients treated with drug-eluting stent (DES) were included in this prospective, observational study. Patients were classified into low fT3 group (n=126) and normal fT3 group (n=402) according to serum fT3 level. Every patient was prospectively interviewed at baseline and 1 year following percutaneous coronary intervention (PCI). HRQOL was assessed with the use of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Low fT3 patients had poorer HRQOL than normal fT3 patients both at baseline and 1-year follow-up (all p<0.05). During 1-year follow-up, HRQOL scores for all patients were significantly higher than baseline. Low fT3 patients had lesser gains in physical functioning, bodily pain, general health, vitality, social functioning and role emotional (all p<0.05). Generally, low fT3 patients demonstrated less improvement in Physical Component Score (PCS) (p=0.008) and Mental Component Score (MCS) (p=0.001). The percentage of patients reaching MCID for PCS and MCS was lower in low fT3 group than that in normal fT3 group (p<0.001). Multivariate linear regression analyses showed that low level of fT3 was an independent risk factor for PCS and MCS improvements. In conclusion, a low fT3 level is a predictor of worse HRQOL improvement in ACS patients treated with DES.

Subclinical hypothyroidism: to treat or not to treat, that is the question! A systematic review with meta-analysis on lipid profile

Previous studies suggested that subclinical hypothyroidism has a detrimental effect on cardiovascular risk factors, and that its effective treatment may have a beneficial impact on overall health. The main purpose of this review and meta-analysis was to assess whether subclinical hypothyroidism treatment is of clinical relevance, based on cardiovascular risk parameters correction. A systemic research of the literature using MEDLINE tool was performed to identify the relevant studies. Only placebo-controlled randomized control trials were included. A quantitative analysis was also performed. This systematic review and meta-analysis of randomized placebo-controlled trials assess the different impact of levothyroxine vs placebo treatment. A significant decrease in serum thyroid-stimulating hormone and total and low-density lipoprotein cholesterol was obtained with levothyroxine therapy (66, 9 and 14%, respectively) and, although modest, this could be significant in terms of reduction of the incidence of coronary artery disease. Other significant results of lipid parameters were not obtained. This systematic review provides a strong evidence-based data in favour of specific changes and beneficial effects of levothyroxine treatment.

The Effects of Altered Membrane Cholesterol Levels on Sodium Pump Activity in Subclinical Hypothyroidism

BACKGROUND

Metabolic dysfunctions characteristic of overt hypothyroidism (OH) start at the early stage of subclinical hypothyroidism (SCH). Na⁺/K⁺-ATPase (the sodium pump) is a transmembrane enzyme that plays a vital role in cellular activities in combination with membrane lipids. We evaluated the effects of early changes in thyroid hormone and membrane cholesterol on sodium pump activity in SCH and OH patients.

METHODS

In 32 SCH patients, 35 OH patients, and 34 euthyroid patients, sodium pump activity and cholesterol levels in red blood cell membranes were measured. Serum thyroxine (T₄) and thyroid stimulating hormone (TSH) levels were measured using enzyme-linked immunosorbent assays. Differences in their mean values were analysed using post hoc analysis of variance. We assessed the dependence of the sodium pump on other metabolites by multiple regression analysis.

RESULTS

Sodium pump activity and membrane cholesterol were lower in both hypothyroid groups than in control group, OH group exhibiting lower values than SCH group. In SCH group, sodium pump activity showed a significant direct dependence on membrane cholesterol with an inverse relationship with serum TSH levels. In OH group, sodium pump activity depended directly on membrane cholesterol and serum T₄ levels. No dependence on serum cholesterol was observed in either case.

CONCLUSION

Despite the presence of elevated serum cholesterol in hypothyroidism, membrane cholesterol contributed significantly to maintain sodium pump activity in the cells. A critical reduction in membrane cholesterol levels heralds compromised enzyme activity, even in the early stage of hypothyroidism, and this can be predicted by elevated TSH levels alone, without any evident clinical manifestations.

The effect of glycaemic control in type 2 diabetic patients with subclinical hypothyroidism

OBJECTIVE

The purpose of this study was to investigate the effect of glycaemic control on subclinical hypothyroidism (SCH) in Chinese type 2 diabetic patients.

METHODS

The study included 476 diabetic patients with SCH admitted for treatment of type 2 diabetes. The controls were selected euthyroid patients with similar characteristics regarding [age, body mass index (BMI), gender, previous hypertension or duration of diabetes, and smoke]. Total cholesterol (TC), LDL cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), the homeostatic model assessment of insulin resistance ratio (HOMA-IR), fasting plasma glucose, hemoglobin A_1c (HbA_1c), as well as plasma levels of thyrotrophin, and free thyroxine (FT4) were assessed at baseline and after 6 months of glycaemic control treatment.

RESULTS

The LDL-C level and HOMA-IR value were significantly higher in the SCH group. Glycaemic control reduced HOMA-IR, HbA_1c, LDL-C, and TG level in patients with SCH. Furthermore, glycaemic control plays a negative effect on thyrotrophin in the SCH group, while this effect was not observed in euthyroid subjects. HbA_1c plays a positive correlation with HOMA-IR (r = 0.048, p < 0.001), fasting plasma glucose (r = 0.086, p < 0.001), LDL-C (r = 0.062, p < 0.001) and TG (r = 0.021, p = 0.009).

CONCLUSION

Our study shows that glycaemic control may bring some benefits to type 2 diabetic patients with SCH.

Comorbidities and characteristics of coronary heart disease patients: their impact on health-related quality of life

BACKGROUND

Patients with coronary heart disease (CHD) commonly present with more than one comorbid condition, contributing to poorer health-related quality of life (HRQoL). The aim of our study was to identify the associations between HRQoL and patient characteristics, vascular comorbidities and anxiety/depression disorders.

METHODS

This observational study was conducted in 36 family medicine practices selected by random stratified sampling from all regions of Slovenia. HRQoL was assessed using the European Quality of Life - 5 Dimensions (EQ-5D) questionnaire and EQ Visual Analogue Scale (EQ-VAS). The associations between HRQoL and patient characteristics stratified by demographics, vascular comorbidities, health services used, their assessment of chronic illness care, and anxiety/depression disorders were identified by ordinal logistic regression and linear regression models.

RESULTS

The final sample included 423 CHD patients with a mean age of 68.0 ± SD 10.8 years; 35.2% were female. Mean EQ-VAS score was 58.6 ± SD 19.9 (median: 60 with interquartile range of 45-75), and mean EQ-5D index was 0.60 ± SD 0.19 (median: 0.56 with interquartile range of 0.41-0.76). The statistically significant predictors of a lower EQ-VAS score were higher family physician visit frequency, heart failure (HF) and anxiety/depression disorders (R² 0.240; F = 17.368; p < 0.001). The statistically significant predictor of better HRQoL, according to EQ-5D was higher patient education, whereas higher family physician visit frequency, HF and peripheral artery disease (PAD) were predictors of poorer HRQoL (Nagelkerke R 2 = 0.298; χ 2 = 148.151; p < 0.001).

CONCLUSIONS

Results of our study reveal that comorbid conditions (HF and PAD), family physician visit frequency and years in education are significant predictors of HRQoL in Slovenian CHD patients.

Hypothyroidism and Lipid Levels in a Community Based Study (TTS)

BACKGROUND

Thyroid hormones play an important role in lipid metabolism. Overt hypothyroidism is known to be associated with increased lipid profiles, but the effect of subclinical hypothyroidism (SCH) on lipid profile remains controversial.

OBJECTIVES

The aim of this study was to assess the association between thyroid disorders and serum lipid levels.

MATERIALS AND METHODS

The present study was conducted within the framework of Tehran lipid and glucose study (TLGS). Serum concentrations of TSH and FT4, cholesterol, triglycerides and HDL-C were measured in 5786 randomly selected subjects. Serum LDL was calculated according to the Friedwald formula.

RESULTS

The study assessed 5154 subjects including 42.5% males and 57.5% females, with a mean age of 39.71 ± 14.2 years (ranged 20 - 90 years). Serum cholesterol was significantly higher in overt hypothyroidism in comparison to subclinical hypothyroidism (P = 0.003). Serum cholesterol, HDL -C, LDL-C and TG did not differ between subclinical hypothyroid and control groups. Among euthyroid men, serum FT4 levels were inversely correlated with serum cholesterol and TG. In euthyroid women, serum FT4 levels were correlated positively with serum HDL-C and negatively correlated with TG and TG/HDL-C ratio and TSH levels were associated negatively with, HDL-C.

CONCLUSIONS

No differences existed in lipid profiles between subclinical hypothyroidism and euthyroid subjects. There are correlations between serum FT4 and TSH and lipid profiles.

The Effects of Six-Month L-Thyroxine Treatment on Cognitive Functions and Event-Related Brain Potentials in Children with Subclinical Hypothyroidism

OBJECTIVE

The aim of this study was to investigate the cognitive status of children with subclinical hypothyroidism (SH) before and after L-thyroxine (L-T4) treatment using event-related potentials (ERPs) and neuropsychological tests.

METHODS

This prospective study was conducted on a series of 20 children with mild SH (free T4 normal and thyroid-stimulating hormone level within 5-10 µIU/L) who underwent clinical and cognitive assessment before L-T4 treatment and 6 months afterwards. The recordings of ERPs were done at the time of diagnosis and after 6 months of euthyroid state. Neuropsychiatric tests for attention, perception, close and remote memory were performed on all patients and on the control group which consisted of 20 healthy children of normal intelligence.

RESULTS

While pretreatment verbal memory (VM) and verbal recall (VR) scores of the SH group were significantly lower than those of the control group (p=0.004 and 0.012, respectively), no significant differences between the post-treatment and control groups were found in these scores after 6 months of L-T4 treatment. Post-treatment VM and VR scores were significantly higher than the pretreatment scores in the SH group (p=0.008 and p=0.0001). There were no significant differences between the pre-and post-treatment values of electrophysiological evaluation in N1, P2, P3 latencies or P3 amplitude (p>0.05), although there was a significant decrease in N2 latency in the post-treatment group (p=0.03).

CONCLUSION

SH affects cognition in children and L-T4 replacement therapy leads to normalization of cognitive functions. Neuropsychological tests can be used as complementary measures in the evaluation of children with SH. Determining the association between ERPs and SH would contribute to the comprehensive evaluation of these children.

Protective Role of Bilirubin Against Increase in hsCRP in Different Stages of Hypothyroidism

In conjunction with thyroxine, bilirubin may play an important role for regulation of hsCRP level and a consequent pro-inflammatory condition in hypothyroidism. In present study we evaluated the dependence of hsCRP changes on total bilirubin (BT) and fT4 level in thirty overt (OH) and thirty subclinical hypothyroidism (SH). Serum BT, hsCRP, thyroxine and TSH were measured in both groups and compared with forty control subjects. Serum values of TSH, hsCRP showed raised (P < 0.001 for both) values with lower levels for fT4 and BT (P < 0.001 and 0.03 respectively) in hypothyroid patients compared to the controls. ANOVA showed significant increments in TSH and hsCRP values with decreases in fT4 among the control, SH and OH groups respectively (P < 0.001). BT values showed decrease in OH group only in comparison to controls (P = 0.04). Regression analysis revealed that hsCRP was negatively dependent on fT4 (β = -0.35, P = 0.002) and serum bilirubin (β = -0.40 and P < 0.001 respectively). Univariate general linear model analysis showed this dependence persisted even when carried out distinctly in SH and OH groups separately (P < 0.001). TSH did not show any significant predictive value on the hsCRP level in either of these two tests. From these analyses we suggest that serum hsCRP is closely integrated to a lowered synthesis of bilirubin and fT4 in hypothyroid patients. Furthermore, this causal relationship is not only limited to overt but also extends to the SH.

Incidence of subclinical hypothyroidism in renal transplant patients

Thyroid disorders are common in chronic kidney disease.

THE AIM

The purpose of this study was to compare thyroid gland disorders among healthy participants and renal transplant patients and to assess the duration of dialysis on thyroid disorders before transplantation.

MATERIAL AND METHODS

Prospective study during 12 months period included 80 participants divided into two groups. Study group of 40 patients with transplanted kidney was divided in two subgroups, according to the time spent on dialysis (i.e. under and over 72 months). The control group included 40 healthy participants. The exclusion criteria was represented by the previous thyroid disorders and systemic illnesses and treatment with drugs that interfere with thyroid function (amiodarone, propranolol, lithium). The blood samples were taken for standard laboratory analysis, total thyroid hormone levels. Serum level of free thyroxine (T4) and free triiodothyronine (T3) were assayed by RIA using commercially available kits. Subclinical hypothyroidism is defined by the finding of elevated thyroid-stimulating hormone (TSH) > 4.4 mmol/L and normal values of T3 and T4.

RESULTS

The relative distribution of the functional thyroid disorders is statistically significantly higher in the experimental group: the low T3 syndrome in 12.5% (n = 5) patients (p = 0.017); low T4 syndrome in 7.5% (n = 3) patients (p = 0.072) and subclinical hypothyroidism in 17.5% (n = 7) patients (p = 0.021). There is statistically significant difference in the relative representation (percentage) between respondents to 72 months and respondents over 72 months duration of hemodialysis, namely: low T3 syndrome, which is a higher percentage was recorded in patients up to 72 months duration of dialysis (19.23%), then subclinical hypothyroidism where a greater percentage recorded in subjects over 72 months duration of dialysis (35.71%) before transplantation.

CONCLUSION

Considering that we are found in kidney transplant patients a significant link of subclinical hypothyroidism with decreased level of T3 and higher incidence of low T3 syndrome, which are associated with increased cardiovascular mortality and morbidity, and act as markers of survival patients after transplantation, it is necessary to conduct a periodically measuring levels of T3, T4 and TSH in these patients in order to assess the relationship between thyroid dysfunction and mortality risk in this population.

Psychiatric and cognitive manifestations of hypothyroidism

PURPOSE OF REVIEW

Overt hypothyroidism has major effects on neuropsychiatric function, but patients with mild hypothyroidism may attribute unrelated neuropsychiatric symptoms to their thyroid condition. This review will summarize data on neuropsychiatric effects of hypothyroidism, and provide guidelines regarding the relationship between hypothyroidism and neuropsychiatric issues, and treatment indications.

RECENT FINDINGS

Clinical investigations and functional imaging studies confirm that overt hypothyroidism is associated with affective and cognitive decrements, largely reversible with treatment. In contrast, subclinical hypothyroidism is not associated with major neuropsychiatric deficits, although studies utilizing sensitive measures show small deficits in memory and executive function. Neuropsychiatric complaints are more common when patients are aware of their thyroid disease, regardless of their thyroid function at the time of testing.

SUMMARY

Neuropsychiatric dysfunction is common in overt hypothyroidism and will improve (perhaps not completely resolve) with therapy. Deficits related to thyroid dysfunction are usually mild in subclinical hypothyroidism, and realistic expectations need to be set regarding symptom reversibility with treatment. Patients with mild hypothyroidism and significant distress related to neuropsychiatric symptoms, most likely, have independent diagnoses that should be evaluated separately.

Alteration of lipid profile in subclinical hypothyroidism: a meta-analysis

BACKGROUND

Previous studies yielded controversial results about the alteration of lipid profiles in patients with subclinical hypothyroidism. We performed a meta-analysis to investigate the association between subclinical hypothyroidism and lipid profiles.

MATERIAL AND METHODS

We searched PubMed, Cochrane Library, and China National Knowledge Infrastructure articles published January 1990 through January 2014. Dissertation databases (PQDT and CDMD) were searched for additional unpublished articles. We included articles reporting the relationship between subclinical hypothyroidism and at least 1 parameter of lipid profiles, and calculated the overall weighted mean difference (WMD) with a random effects model. Meta-regression was used to explore the source of heterogeneity among studies, and the Egger test, Begg test, and the trim and fill method were used to assess potential publication bias.

RESULTS

Sixteen observational studies were included in our analysis. Meta-analysis suggested that the serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and total triglyceride levels were significantly increased in patients with subclinical hypothyroidism compared with euthyroidism individuals; the WMD were 12.17 mg/dl, 7.01 mg/dl, and 13.19 mg/dl, respectively (P<0.001 for all). No significant difference was observed for serum high-density lipoprotein cholesterol (HDL-C). Match strategy was the main source of heterogeneity among studies in TC and LDL-C analysis. Potential publication bias was found in TC and LDL-C analysis by the Egger test or Begg test and was not confirmed by the trim and fill method.

CONCLUSIONS

Subclinical hypothyroidism may correlate with altered lipid profile. Previous studies had limitations in the control of potential confounding factors and further studies should consider those factors.

Serum Phospholipase A2-IIA, hs-CRP, and Lipids in Women With Subclinical Hypothyroidism

BACKGROUND

Subclinical hypothyroidism (SCH) is a metabolic disorder characterized by elevated TSH level but normal T4 level. Some previous studies suggest that SCH is associated with inflammation.

OBJECTIVES

The present study aimed to compare lipid serum levels in SCH patients and normal participants, also explore possible association between SCH and the two inflammatory markers hs-CRP and PLA2-IIA.

PATIENTS AND METHODS

This study was performed on 77 women aged 20-45 (39 with SCH and 38 in the control group). TSH and T4 levels were measured by electrochemiluminescenceassay. Lipid profiles were analyzed using enzymatic-colorimetric methods. Hs-CRP and PLA2-IIA were determined using the ELISA method. IBM SPSS 19.0 was used for statistical analysis.

RESULTS

Serum levels of TG, cholesterol, and LDL were higher in the SCH group than the control group. However, there was no significant difference between the two groups for HDL level. Likewise, no difference was observed for the serum level of hs-CRP. PLA2-IIA mean value was higher in the SCH group.

CONCLUSIONS

SCH is associated with increased level of PLA2-IIA, which is independent of BMI. The stronger association of SCH with PLA2-IIA than with hs-CRP indicates that PLA2-IIA is an inducer of inflammation while hs-CRP is not.

Prevalence and risk factors of subclinical thyroid disease

Subclinical thyroid disease is defined biochemically by an abnormal thyrotropin (TSH) level and normal serum-free thyroxine level. The prevalence of this condition varies according to the reference range for TSH and geographic or demographic factors. Recently, several studies, including our community-based cohort studies, have reported on the incidence of subclinical thyroid disease in Korea. Using these studies, we reviewed the prevalence and risk factors of subclinical thyroid disease, focusing on subclinical hypothyroidism.

Cardiovascular risk and quality of life in elderly people with mild thyroid hormone deficiency

Subclinical hypothyroidism (sHT) is a common condition in the general population, the prevalence increases with age, especially in women. An association between sHT and increased coronary heart disease (CHD) and heart failure (HF) risk and mortality has been described. However, this association is far to be established in older people (>65 years), especially in the oldest old (>85 years). Individuals with sHT may experience symptoms that resemble those observed in the overt form of the disease, leading to an impaired quality of life (QoL). Although very old people are frequently frail and potentially more susceptible to the effects of a disease, few studies were designed to assess the effect of sHT on QoL in this subset of population. Interestingly, the serum TSH concentration curve of general population has a skewed distribution with a "tail" toward higher values, which is amplified with aging. Thus, the diagnosis of sHT and the interpretation of its potential effects on CV function and QoL in older people may be a challenge for the clinician. Giving these premises, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) since 1980 regarding hypothyroidism, sHT, elderly, cardiovascular risk, CHD or HF events and mortality, health-related QoL, and LT4 therapy. Consistent results among large prospective cohort studies suggest an age-independent relationship between sHT and HF progression, while an impact of sHT on CHD events and mortality is essentially reported in young adults (aged below 65-70 years) with long-lasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described.

Thyroid hormone status and health-related quality of life in the LifeLines Cohort Study

BACKGROUND

Thyroid disorders are prevalent in Western society, yet many subjects experience limited symptoms at diagnosis, especially in hypothyroidism. We hypothesize that health-related quality of life (HR-QOL) is more severely impaired in subjects with more abnormal thyroid hormone function tests.

METHODS

This is a cross-sectional study of Dutch adults participating in the LifeLines Cohort Study between December 2009 and August 2010. In 9491 Western European participants (median age 45 years; 3993 men and 5498 women), without current or former use of thyroid medication, we compared HR-QOL using the RAND 36-Item Health Survey between subjects with normal thyrotropin (TSH) values and subjects with disturbed thyroid hormone status (serum TSH, free thyroxine, and free triiodothyronine). The influence of possible confounders (age, smoking, co-morbidity) on HR-QOL was evaluated as well.

RESULTS

Suppressed TSH values (TSH < 0.5 mU/L) were found in 114 (1.2%), while 8334 (88.8%) had TSH within the normal range, 973 participants (10.3%) had TSH between 4 and 10 mU/L, and 70 (0.7%) had TSH > 10 mU/L. Men had a higher HR-QOL than women (70-92 vs. 65-89; p < 0.001), except for the domain "general health" (72 vs. 72; p = 0.692). Men with suppressed or elevated TSH values did not score significantly lower than euthyroid men for any of nine domains of the RAND 36-Item Health Survey. Compared with euthyroid women, women with suppressed TSH scored significantly lower in the domains "physical functioning" (84 vs. 89, p = 0.013) and "general health" (67 vs. 72, p = 0.036). Women with markedly elevated TSH (> 10 mU/L) had a score in all HR-QOL domains that was similar to that of women with normal TSH values. There were no differences in the physical component score and the mental component score between any of the TSH groups. Physical component score and mental component score were mainly determined by smoking status, co-morbidity, and body mass index or waist circumference.

CONCLUSIONS

In this population-based study, HR-QOL scores of subjects with suppressed TSH values or markedly elevated TSH values were generally not significantly lower than those of subjects with normal or mildly elevated TSH values.

Patient-reported outcomes in adequately treated hypothyroidism - insights from the German versions of ThyDQoL, ThySRQ and ThyTSQ

BACKGROUND

Disease-specific patient-reported outcome measures (PROMs) have been developed as important research tools in the study of various diseases. For hypothyroidism there exist three validated disease-specific questionnaires in English: the Thyroid-Dependent Quality of Life Questionnaire (ThyDQoL), the Underactive Thyroid Symptom Rating Questionnaire (ThySRQ) and the Thyroid Treatment Satisfaction Questionnaire (ThyTSQ). We report psychometric properties of new German versions of the questionnaires including construct validity from two independent samples.

METHODS

230 envelopes with ThyDQoL, ThySRQ and ThyTSQ were given out to patients receiving levothyroxine for diagnosed hypothyroidism. Reliability and factor analyses were performed, correlations and hypothesised subgroup differences calculated to assess psychometric properties. Independently, 18 patients with treated hypothyroidism for autoimmune thyroiditis (Hashimoto’s disease) and 18 healthy control subjects were enrolled in a clinical study. Participants filled in the above questionnaires alongside well-known generic PROMs, e.g. the Beck Depression Inventory, the 12-item Well-Being Questionnaire and the Short-Form-36. Two blood samples were taken. Groups were compared and correlations between disease-specific and generic instruments analysed. Relationships between PROMs and biochemically determined thyroid hormone status were investigated.

RESULTS

102 patients returned completed questionnaires (response rate 44%). The newly translated questionnaires had satisfactory psychometric properties. Cronbach’s alpha was 0.92 for ThyDQoL, 0.81 for ThySRQ and 0.86 for ThyTSQ. For each of the questionnaires, a single factor structure explained the data best. Adequately treated patients with thyroid stimulating hormone levels in the upper normal range reported more symptoms in the ThySRQ. Those with autoimmune hypothyroidism reported being more bothered by depressive symptoms. Within the clinical sample, correlation with well-known generic instruments revealed good construct validity. In the clinical sample patients reported more symptoms in the ThySRQ, being more bothered by tiredness, higher depression and reduced well-being despite biochemically adequate treatment. Correlations between PROMs and biochemical thyroid hormone status revealed moderate though consistent associations.

CONCLUSIONS

Psychometric properties including construct validity of German versions of the ThyDQoL, ThySRQ and ThyTSQ are satisfactory. Feasibility and sensitivity in a clinical sample could be shown. We encourage the use of disease-specific PROMs in future studies as important additions to generic instruments in clinical research on hypothyroidism.

Secondary prevention in patients with coronary heart diseases: what factors are associated with health status in usual primary care?

Background

For patients with coronary heart diseases a substantial part of secondary prevention is delivered in primary care. Along with the growing importance of prevention, health-related quality of life (HRQoL) is an indicator of patient-centered care that has gained increased attention. Different approaches for reorganization in primary care have been associated with improvements in HRQoL. However, these are often results of complex interventions. Evidence on aspects concerning usual primary care that actually have an impact on HRQoL remains scarce. Therefore, this observational study aimed to identify factors which are associated with HRQoL in usual primary care at practice and patient-level.

Methods

This observational study was conducted in eight European countries. We were able to match data from survey instruments for 3505 patients with coronary heart disease (CHD) in 228 practices. A multilevel analysis was performed to identify associations of EQ-5D scores at patient and practice-level.

Results

After dropping patients with missing information, our cohort consisted of 2656 patients. In this sample, 30.5% were female and the mean age was 67.5 years (SD 10.1). The final model included a total set of 14 potential explanatory variables. At practice-level no variable was associated with EQ-5D. At patient-level, lower education (r = −0.0381, p<0.0001), female gender (r = −0.0543, p<0.0001) and a higher number of other conditions (r = −0.0340, p<0.0001), had a strong negative effect on HRQoL. Strong positive associations with HRQoL were found for a good medication adherence (Morisky) (r = 0.0195, p<0.0001) and more positive evaluations of physicians' clinical behavior (r = 0.0282, p = 0.002). In terms of HRQoL no differences between single-handed and group practices exist.

Conclusion

The results of our study suggest that a better patient-physician relationship rather than organization of CHD care is associated with higher HRQOL in the primary care setting. The results may imply that interventions to improve HRQoL require a strong patient-centered approach.

Elevated thyroid stimulating hormone is associated with elevated cortisol in healthy young men and women

BACKGROUND

Recent attention has been given to subclinical hypothyroidism, defined as an elevation of TSH (4.5-10 uIU/L) with T4 and T3 levels still within the normal range. Controversy exists about the proper lower limit of TSH that defines patients in the subclinical hypothyroidism range and about if/when subclinical hypothyroidism should be treated. Additional data are needed to examine the relationship between markers of thyroid function in the subclinical hypothyroidism range, biomarkers of health and ultimately health outcomes.

OBJECTIVE

We aimed to assess the relationship between serum TSH levels in the 0.5-10 uIU/L range and serum cortisol in a cohort of healthy young men and women without clinical evidence of hypothyroidism. Based on data in frank hypothyroidism, we hypothesized that serum TSH levels would be positively correlated with serum cortisol levels, suggesting derangement of the cortisol axis even in subclinical hypothyroidism.

METHODS

We conducted a cross sectional study in 54 healthy, young (mean 20.98 +/- 0.37 yrs) men (19) and women (35). Lab sessions took place at 1300 hrs where blood was drawn via indwelling catheter for later assessment of basal serum TSH, free T3, free T4, and cortisol levels.

RESULTS

All but 1 participant had free T3 levels within the normal reference intervals; free T4 levels for all participants were within the normal reference intervals. Linear regression modeling revealed that TSH levels in the 0.5-10 uIU/L were significantly and positively correlated with cortisol levels. This positive TSH-cortisol relationship was maintained below the accepted 4.5 uIU/L subclinical hypothyroid cutoff. Separate regression analyses conducted by systematically dropping the TSH cutoff by 0.50 uIU/L revealed that the TSH-cortisol relationship was maintained for TSH levels (uIU/L) ≤4.0, ≤3.5, ≤3.0, and ≤2.5 but not ≤2.0. Linear regression modeling did not reveal a relationship between free T3 or free T4 levels and cortisol levels.

CONCLUSIONS

Results suggest a positive relationship between TSH and cortisol in apparently healthy young individuals. In as much as this relationship may herald a pathologic disorder, these preliminary results suggest that TSH levels > 2.0 uIU/L may be abnormal. Future research should address this hypothesis further, for instance through an intervention study.

Lipid abnormalities and cardiometabolic risk in patients with overt and subclinical thyroid disease

Dyslipidemia is a common finding in patients with thyroid disease, explained by the adverse effects of thyroid hormones in almost all steps of lipid metabolism. Not only overt but also subclinical hypo- and hyperthyroidism, through different mechanisms, are associated with lipid alterations, mainly concerning total and LDL cholesterol and less often HDL cholesterol, triglycerides, lipoprotein (a), apolipoprotein A1, and apolipoprotein B. In addition to quantitative, qualitative alterations of lipids have been also reported, including atherogenic and oxidized LDL and HDL particles. In thyroid disease, dyslipidemia coexists with various metabolic abnormalities and induce insulin resistance and oxidative stress via a vice-vicious cycle. The above associations in combination with the thyroid hormone induced hemodynamic alterations, might explain the increased risk of coronary artery disease, cerebral ischemia risk, and angina pectoris in older, and possibly ischemic stroke in younger patients with overt or subclinical hyperthyroidism.

The TSH upper reference limit: where are we at?

The diagnosis of subclinical hypothyroidism--serum TSH levels above and T(4) levels within the laboratory reference ranges--depends critically on the upper limit of the TSH reference interval. Calls have been made to lower the current upper TSH reference limit of 4.0 mU/l to 2.5 mU/l to exclude patients with occult hypothyroidism. However, data from population studies do not indicate that the distribution of TSH is altered owing to inclusion of such individuals. The opposite suggestion has also been put forward; the TSH upper reference limit is often too low, especially in the elderly, in women and in white individuals, which may lead to unnecessary or even harmful therapy. Studies in elderly individuals have shown that although aging may be associated with increased TSH levels, paradoxically, overt hypothyroidism in this population may be associated with a less robust TSH response than in young individuals. This Review highlights the interindividual and intraindividual variability of TSH levels and discusses the current controversy that surrounds the appropriateness of reference ranges defined on the basis of age, race, sex and amount of iodine intake. Moreover, the current evidence on lowering or increasing the upper limit of the TSH reference interval is reviewed and the need to individualize levothyroxine treatment in patients with elevated TSH levels is discussed.