Does Subclinical Hypothyroidism Add Any Symptoms? Evidence from a Danish Population-Based Study

The dangerous trend of levothyroxine medicalization

Thyroid hormone replacement is paramount in overt hypothyroidism; recently, however, thyroid hormone substitution is increasingly prescribed to patients with normal thyroid hormone levels. This forum article discusses the complex causes and the possible negative effects of overusing thyroid hormone replacement drugs.

Determinants for Thyroid Hormone Replacement Therapy in Subclinical Hypothyroidism: A Multicenter Electronic Health Records-Based Study

Background: The frequency and factors associated with thyroid hormone replacement therapy among patients with subclinical hypothyroidism (SCH) remain uncertain. Methods: In this electronic health records-based observational cohort study, we included adults diagnosed with SCH from four academic centers (the United States and Mexico) from January 1, 2016, to December 31, 2018. We aimed to identify the determinants of thyroid hormone replacement therapy for SCH and the frequency of treated SCH. Results: A total of 796 patients (65.2% women) had SCH, and 165 (20.7%) were treated with thyroid hormone replacement therapy. The treated group was younger [51.0 (standard deviation {SD} 18.3) vs. 55.3 (SD 18.2) years, p = 0.008] and had a higher proportion of women (72.7% vs. 63.2%, p = 0.03) compared with the untreated group. Only 46.7% of patients in the treated group and 65.6% in the untreated group had confirmatory thyroid function tests (TFTs) before the decision to start thyroid hormone replacement therapy was made. There was no difference in the frequency of thyroid autoimmunity evaluation, but a positive thyroid autoimmunity test was more frequent in the treated group compared with the untreated group (48.2% vs. 20.3%, p < 0.001). In a multivariable logistic regression model, female sex (odds ratio [OR] = 1.71 [CI 1.13-2.59], p = 0.01) and index thyrotropin (TSH) level (OR = 1.97 [CI 1.56-2.49], p < 0.001 for every SD [2.75 mIU/L] change) were associated with higher odds of treatment. Conclusions: Among patients with SCH, female sex and index TSH level were associated with higher odds of treatment. Moreover, in our population, the decision to treat or not to treat SCH was often based on only one set of abnormal TFTs, and thyroid autoimmunity assessment was underused.

Hypothyroidism and Somatization: Results from E-Mode Patient Self-Assessment of Thyroid Therapy, a Cross-Sectional, International Online Patient Survey

Background: Between 10% and 15% of hypothyroid patients experience persistent symptoms despite achieving biochemical euthyroidism. Unexplained persistent symptoms can be a sign of somatization. This is associated with distress and high health care resource use and can be classified as somatic symptom disorder (SSD). Prevalence rates for SSD differ depending on classification criteria and how they are ascertained, varying between 4% and 25%. As this has not been studied in hypothyroid patients before, the aim of this study was to document somatization in people with hypothyroidism and to explore associations with other patient characteristics and outcomes. Methods: Online, multinational cross-sectional survey of individuals with self-reported, treated hypothyroidism, which included the validated Patient Health Questionnaire-15 (PHQ-15) for assessment of somatization. Chi-squared tests with the Bonferroni correction were used to explore outcomes for respondents with a PHQ-15 score ≥10 (probable somatic symptom disorder [pSSD]) versus a PHQ-15 score <10 (absence of SSD). Results: A total of 3915 responses were received, 3516 of which contained the valid PHQ-15 data (89.8%). The median score was 11.3 (range 0-30 [confidence interval 10.9-11.3]). The prevalence of pSSD was 58.6%. Associations were found between pSSD and young age (p < 0.001), women (p < 0.001), not working (p < 0.001), having below average household income (p < 0.001), being treated with levothyroxine (LT4) (rather than combination of LT4 and L-triiodothyronine [LT3], LT3 alone, or desiccated thyroid extract) (p < 0.001), expression of the view that the thyroid medication taken did not control the symptoms of hypothyroidism well (p < 0.001), and with number of comorbidities (p < 0.001). pSSD was associated with respondent attribution of most PHQ-15 symptoms to the hypothyroidism or its treatment (p < 0.001), dissatisfaction with care and treatment of hypothyroidism (p < 0.001), a negative impact of hypothyroidism on daily living (p < 0.001), and with anxiety and low mood/depression (p < 0.001). Conclusions: This study demonstrates a high prevalence of pSSD among people with hypothyroidism and associations between pSSD and negative patient outcomes, including a tendency to attribute persistent symptoms to hypothyroidism or its treatment. SSD may be an important determinant of dissatisfaction with treatment and care among some hypothyroid patients.

Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement

Persistent symptoms in patients treated for hypothyroidism are common. Despite more than 20 years of debate, the use of liothyronine for this indication remains controversial, as numerous randomised trials have failed to show a benefit of treatment regimens that combine liothyronine (T3) with levothyroxine over levothyroxine monotherapy. This consensus statement attempts to provide practical guidance to clinicians faced with patients who have persistent symptoms during thyroid hormone replacement therapy. It applies to non-pregnant adults and is focussed on care delivered within the UK National Health Service, although it may be relevant in other healthcare environments. The statement emphasises several key clinical practice points for patients dissatisfied with treatment for hypothyroidism. Firstly, it is important to establish a diagnosis of overt hypothyroidism; patients with persistent symptoms during thyroid hormone replacement but with no clear biochemical evidence of overt hypothyroidism should first have a trial without thyroid hormone replacement. In those with established overt hypothyroidism, levothyroxine doses should be optimised aiming for a TSH in the 0.3-2.0 mU/L range for 3 to 6 months before a therapeutic response can be assessed. In some patients, it may be acceptable to have serum TSH below reference range (e.g. 0.1-0.3 mU/L), but not fully suppressed in the long term. We suggest that for some patients with confirmed overt hypothyroidism and persistent symptoms who have had adequate treatment with levothyroxine and in whom other comorbidities have been excluded, a trial of liothyronine/levothyroxine combined therapy may be warranted. The decision to start treatment with liothyronine should be a shared decision between patient and clinician. However, individual clinicians should not feel obliged to start liothyronine or to continue liothyronine medication provided by other health care practitioners or accessed without medical advice, if they judge this not to be in the patient's best interest.

Treating subclinical hypothyroidism in individuals with or without mental health problems -A Delphi based expert consensus study in two countries

Background

Subclinical hypothyroidism (SCH) is a common endocrine problem with prevalence estimates between 4% and 20%. Symptoms are often non-specific but can substantially affect well-being leading to repeated medical consultations. The effect of thyroid hormone replacement therapy (THRT) in patients with SCH remains uncertain. Current guidelines, limited by the lack of high-quality evidence, have been controversial with limited adherence in clinical practice.

Methods

Three-round modified Delphi method to establish consensus regarding diagnosis and treatment of individuals with SCH with and without affective disorder or anxiety, conducted with clinicians from three specialties, general practice, endocrinology and psychiatry, and two countries, Sweden and the United Kingdom.

Results

Sixty clinicians, 20 per specialty, were recruited. Fifty-three (88%) participants completed all three rounds. The participants reached consensus on five of the 26 practice statements that (a) repeated testing was required for the diagnosis of subclinical hypothyroidism, (b) antibody screening should usually occur, and (c and d) antibody screening would strengthen the indication for thyroid hormone replacement therapy in both individuals with or without affective disorder or anxiety. The participants disagreed with (e) a requirement of a TSH threshold ≥ 20 mIU/L for thyroid hormone replacement therapy start. Psychiatrists and GPs but not endocrinologists, agreed that there was a frequent discrepancy between laboratory results and clinical symptoms, and disagreed that testing for thyroid dysfunction was overused in patients presenting with depression or anxiety, or fatigue.

Conclusions

In many aspects, attitudes toward diagnosing and treating SCH remain diverse. The inability of our Delphi panel to achieve consensus on most items and the disagreement with a TSH ≥ 20 mIU/L threshold for treatment suggest that the concept of SCH may need rethinking with a better understanding of the hypothalamic-pituitary-thyroid physiology. Given that the scientific evidence is currently not conclusive, guidelines in this area should not be taken as definitive.

Hypothyroidism: The difficulty in attributing symptoms to their underlying cause

Common symptoms of overt hypothyroidism are non-specific and include fatigue, lethargy, and dry skin. Although the diagnosis is considered to be straightforward, no single symptom can be used to identify patients with overt hypothyroidism, while many patients with subclinical hypothyroidism are asymptomatic. A large population-based study on the spectrum of symptoms in subclinical hypothyroidism showed similar rates of thyroid disease-related symptoms compared with euthyroid subjects, while the TSH concentration had no impact on symptom score. Together, these findings make it challenging to attribute symptoms to their underlying cause. This is also true in the case of unexplained persistent symptoms in levothyroxine-treated patients. Although generally considered a life-long replacement therapy, successful thyroid hormone discontinuation resulting in euthyroidism has been reported in approximately one third of patients. Thus, we overtreat patients with (subclinical) hypothyroidism, highlighting the importance of reliable diagnostic criteria. The diagnostic process, including the implementation of robust TSH and FT4 reference intervals, is especially challenging in specific situations including aging, pregnancy, non-thyroidal illness, and central hypothyroidism. There is a clear need for improved adherence to current guidelines from scientific societies and for willingness to manage symptoms without a clear pathological correlate, especially in the case of mild TSH elevations. This review will highlight recent literature on this topic and offers some practice points.

Use of thyroid hormones in hypothyroid and euthyroid patients: a 2020 THESIS questionnaire survey of members of the Hellenic Endocrine Society

PURPOSE

To investigate current practices of specialists in the use of thyroid hormone preparations in Greece as part of an ongoing international survey, namely THESIS-Treatment of Hypothyroidism in Europe by Specialists: an International Survey.

METHODS

An electronic link leading to an anonymized questionnaire was sent to all (n = 837) members of the Hellenic Endocrine Society.

RESULTS

In total, 501 respondents participated in the survey, though only part of the questionnaire was filled in by some participants. A total of 88.2% were endocrinologists and 57.9% worked in private practice. Levothyroxine (LT4) was the first-line choice (98.6%) for the treatment of hypothyroid patients. In total, 70.2% preferred LT4 soft-gel capsules for patients reporting intolerance to various foods. Soft-gel capsules were the preferred LT4 formulation for patients on generic LT4 and with unexplained poor biochemical control of hypothyroidism (66.3%) or inability to take LT4 fasted and separate from food/drink (68.3%). It was found that 48.4% would never use combined LT4 + LT3. However, 25% would use combination therapy for a short period in patients recovering from protracted hypothyroidism or in patients with normal serum TSH but persistent symptoms. Concerning euthyroid individuals, 31.9% considered treatment with thyroid hormones in infertile females with positive thyroid antibodies and 24.4% in patients with growing goiter. Selenium or iodine supplementation was used occasionally, mostly in patients with coexisting autoimmune thyroiditis.

CONCLUSIONS

LT4 tablets are the treatment of choice for hypothyroidism in Greece. Several conditions may lead to various other practices, some of which deviate from current evidence-based guidelines and need more scrutiny.

Treating hypothyroidism is not always easy: When to treat subclinical hypothyroidism, TSH goals in the elderly, and alternatives to levothyroxine monotherapy

The majority of patients with hypothyroidism feel better when levothyroxine treatment restores thyroid-stimulating hormone (TSH) concentrations to normal. Increasingly, a significant minority of patients remain symptomatic and are dissatisfied with their treatment. Overzealous treatment of symptomatic patients with subclinical hypothyroidism may contribute to dissatisfaction among hypothyroidism patients, as potential hypothyroid symptoms in patients with minimal hypothyroidism rarely respond to treatment. Thyroid hormone prescriptions have increased by 30% in the United States in the last decade. The diagnosis of subclinical hypothyroidism should be confirmed by repeat thyroid function tests ideally obtained at least 2 months later, as 62% of elevated TSH levels may revert to normal spontaneously. Generally, treatment is not necessary unless the TSH exceeds 7.0-10 mIU/L. In double-blinded randomized controlled trials, treatment does not improve symptoms or cognitive function if the TSH is less than 10 mIU/L. While cardiovascular events may be reduced in patients under age 65 with subclinical hypothyroidism who are treated with levothyroxine, treatment may be harmful in elderly patients with subclinical hypothyroidism. TSH goals are age dependent, with a 97.5 percentile (upper limit of normal) of 3.6 mIU/L for patients under age 40, and 7.5 mIU/L for patients over age 80. In some hypothyroid patients who are dissatisfied with treatment, especially those with a polymorphism in type 2 deiodinase, combined treatment with levothyroxine and liothyronine may be preferred.

Local symptoms of Hashimoto's thyroiditis: A systematic review

OBJECTIVE

Hashimoto's thyroiditis (HT) is the most common type of thyroid disease and can cause many different manifestations. The local symptoms of HT are an under-studied area of research. Therefore, the purpose of this study was to investigate the local symptoms of HT and their prevalence.

METHODS

A systematic review was performed to find articles in PubMed that discuss the local symptoms of HT. Relevant vocabulary terms and key terms included: autoimmune thyroid disease (AITD), hyperthyroidism, hypothyroidism, neck, throat, pharynx, airway, esophagus, breathe, swallow, globus, sleep apnea, symptoms, and quality of life. Two investigators independently screened the eligible studies.

RESULTS

A total of 54 articles fulfilled the inclusion criteria. Of these, 25 were clinical studies, 24 were case reports, and five were reviews. These clinical studies and case reports included a total of 2660 HT patients. There were eight local symptoms related to HT: neck pain (0.02%~16%), voice changes (7%~30%), throat discomfort (20%~43.7%), shortness of breath (28%~50%), dysphagia (29%), goiter-related symptoms (69.44%), sleep apnea, and generally defined compressive symptoms. Due to the use of different outcome measures among all the studies, a meta-analysis of the data could not be performed.

CONCLUSION

Goiter symptoms, which are an item on the ThyPRO scales, are the most frequent local symptoms in HT patients, and include neck pain, voice changes, throat discomfort, and dysphagia. These local symptoms should be identified in the clinic and included in the early diagnosis and management of HT, as well as evaluated further to understand their relevance in the pathogenesis of HT.

Underlying conditions contributing to breathlessness in the population

PURPOSE OF REVIEW

Assessment of underlying conditions that contribute to breathlessness is fundamental for symptom management. This review aims to summarize the knowledge from the past two years on the most common underlying conditions among individuals with breathlessness in the general population and to identify research gaps.

RECENT FINDINGS

Nine studies from the last two years were included in the review; two studies systematically assessed underlying conditions among breathless individuals in the general population. The modified Medical Research Council (mMRC) scale was used in eight of nine studies. Respiratory diseases were the main underlying condition (40-57%), of which asthma was the most common (approx. 25%), and chronic obstructive pulmonary disease was particularly strongly associated with breathlessness. Other conditions prevalent among breathless individuals included heart diseases, anxiety, depression, and obesity, and several conditions often co-existed.

SUMMARY

Breathlessness in the general population is common and associated with several underlying conditions. Respiratory disease is the most commonly reported underlying condition. Refined methods such as machine learning could be useful to study the complex interplay between multiple underlying causes of breathlessness and impact on outcomes such as quality of life and survival.