Prevalence, incidence and associated comorbidities of treated hypothyroidism: an update from a European population

Thyroid diseases and female sexual dysfunctions

INTRODUCTION

Female sexual dysfunctions (FSDs) have received little attention in the context of thyroid diseases, despite the high prevalence of both conditions.

OBJECTIVES

This review aims to update and summarize the state of knowledge on the association between thyroid diseases and FSDs and to investigate the complex mechanisms through which thyroid hormone imbalance can impact female sexual health in the context of the biopsychosocial model.

METHODS

A comprehensive literature search was performed through the PubMed, MEDLINE, and Scopus databases, using the following keywords: "female sexual function," "sexual dysfunction," "hypoactive sexual desire disorder," "thyroid disease," "thyroiditis," "hypothyroidism," and "hyperthyroidism."

RESULTS

To date, well-designed studies that describe the relationship between FSDs and thyroid disorders are lacking. However, despite the limitations on available studies, current data indicate that sexual alterations are frequently associated with thyroid diseases in women. A complex interplay of direct and indirect hormonal and nonhormonal mechanisms has been hypothesized, including hormonal changes, neurotransmitter imbalance, reduced nitric oxide release, mood disorders, and other systemic consequences of both hypothyroidism and hyperthyroidism. Thyroid hormone receptors have also been identified in the genitourinary system.

CONCLUSIONS

In a clinical setting, physicians should investigate the sexuality of patients consulting for thyroid disease. At the same time, an evaluation of thyroid function should be performed in patients presenting with FSD, especially after menopause, when the risk of thyroid diseases and FSDs increases strongly.

Scientific yoga module for hypothyroidism: A study protocol for tele-yoga RCT

Background

Management of thyroid dysfunction has a direct effect on the quality of life and studies have recognized that hypothyroidism has become a public health challenge. Although conventional medicine is widely used, its long-term side effects are elucidated. This study aims to conduct a randomized controlled trial (RCT) through tele-mode to assess the effectiveness of the newly developed and validated "Scientific Yoga Module" as a telehealth concept for improving the quality of life in patients with hypothyroidism along with management of other symptoms as compared to the standard of care.

Method

This is a single-blinded, two-arm, parallel-group RCT in which at least a total of 120 primary hypothyroid subjects both male and female between the age group 18 to 60 will be recruited from the database of Swami Vivekananda Yoga Anusandhana Samsthana (SVYASA). Participants will be randomly divided into a yoga intervention group (n = 60) and a waitlist control group (n = 60) as per the inclusion and exclusion criteria of the study. A tele-yoga intervention for six months will be administered and pre-interim-post data will be recorded for both groups. This protocol is designed to study the effect of Scientific Yoga Module intervention on primary assessments of SF-36 scale [health-related quality of life (HRQOL) that includes physical, mental, emotional, and social states] along with secondary assessments on the biochemical test of thyroid profile-{Triiodothyronine (T³), Thyroxine (T⁴), Thyroid Stimulating Hormones (TSH)}, Body Mass Index (BMI), Blood Pressure (BP), Fatigue Assessment Scale (FAS), Perceived Stress Scale (PSS), Gita Inventory of personality scale (GIP).

Conclusion

To the best of our knowledge, this tele-yoga RCT for hypothyroidism will be the first clinical trial to analyze the effectiveness of a "Scientific Yoga Module" imparted through tele-mode.

Coexistence of TSH-secreting adenoma and primary hypothyroidism: a case report and review of literature

BACKGROUND

Thyrotropin-secreting adenoma (TSHoma) is the least common type of pituitary adenoma, these patients often present with symptoms of hyperthyroidism. When TSHoma patients combined with autoimmune hypothyroidism, it is critically difficult to diagnose for the specific confusion in the results of thyroid function test.

CASE PRESENTATION

One middle-aged male patient was presented with a sellar tumor on cranial MRI for headache symptoms. After hospitalization, a significant increase in thyrotropin (TSH) was revealed by the endocrine tests, while free thyronine (FT3) and free thyroxine (FT4) decreased, and the diffuse destruction of thyroid gland was revealed by thyroid ultrasound. Based on the endocrine test results, the patient was diagnosed as autoimmune hypothyroidism. After the multidisciplinary discussion, the pituitary adenoma was removed by endoscopic transnasal surgery, until the tumor was completely excised, for which TSHoma was revealed by postoperative pathology. A significant decrease of TSH was revealed by the postoperative thyroid function tests, the treatment for autoimmune hypothyroidism was conducted. After 20 months of follow-up, the thyroid function of patient had been improved significantly.

CONCLUSION

When the thyroid function test results of patients with TSHoma are difficult to interpret, the possibility of combined primary thyroid disease should be considered. TSHoma combined with autoimmune hypothyroidism is rare, which is difficult to diagnose. The multidisciplinary collaborative treatment could help to improve the outcomes of treatment.

Diagnosis and Treatment of Nonfunctioning Pituitary Adenomas with Thyroid Disorders

OBJECTIVE

Patients with nonfunctioning pituitary adenoma (NFPA) can present with different types of thyroid disorders, which are easily misdiagnosed or missed and can even result in serious clinical consequences. This study was to summarize the different types of thyroid disorders in patients with NFPA with the aim of providing references for the diagnosis and treatment of such patients.

MATERIALS AND METHODS

The data of pituitary adenoma (PA) patients who underwent surgical treatment at Xuanwu Hospital, Capital Medical University, from 2017 to 2021 were retrospectively analyzed, and NFPA patients with preoperative thyroid disorders were screened out to analyze their imaging, endocrine, treatment, and prognosis data. Also, thyroid disorders were classified to summarize diagnostic methods and treatment principles for different types of thyroid disorders.

RESULTS

A total of 399 NFPA patients were included in this study, of which 67 (16.8%) had thyroid disorders before surgery. Fifty-four patients had (13.5%) central hypothyroidism (CH) caused by NFPA and were treated with levothyroxine (L-T4) supplementation before and after operation. Eleven patients (2.8%) had primary hypothyroidism and were treated with L-T4 during the perioperative period, and long-term treatment of primary hypothyroidism was provided after surgery. Two NFPA patients (0.5%) were combined with primary hyperthyroidism and treated with medication for primary hyperthyroidism after tumor resection.

CONCLUSION

Thyroid disorders are relatively common in patients with NFPA, but are difficult to be diagnosed due to their different types. CH is the most common type of thyroid disorder, which requires aggressive L-T4 supplementation during the preoperative period. The primary disease of the thyroid gland is easily missed when NFPA is combined with primary hypothyroidism or primary hyperthyroidism, and the thyroid function test results require to be analyzed carefully for continued treatment for thyroid disease after resection of the NFPA.

Benign paroxysmal positional vertigo: is hypothyroidism a risk factor for recurrence?

OBJECTIVE

To investigate the relationship between risk of Benign Paroxysmal Positional Vertigo (BPPV) recurrence and hypothyroidism treated with hormone replacement therapy (HRT).

METHODS

797 patients with idiopathic BPPV were divided into two groups: 250 patients with recurrence of BPPV (R-BPPV) and 547 patients without recurrence (NR-BPPV). Regarding patients with thyroid disease on HRT, we collected serum test results of thyroid-stimulating hormone (TSH), free triiodothyronine f-T3, free thyroxine f-T4, thyroglobulin antibodies (TG-Ab) and thyroid peroxidase antibodies (TPO-Ab).

RESULTS

Hypothyroidism in long-term HRT was found in 61/250 (24.4%) patients of the R-BPPV group vs 79/547 (14.4%) of the NR-BPPV-group (p = 0.0006). Hashimoto thyroiditis (HT) was associated with recurrence (p < 0.0001). A significant correlation was found between recurrence and level of serum TPO-Ab (p = 0.0117) and TG-Ab (p = 0.0025), but not with mean serum TSH, f-T3 and f-T4.

CONCLUSIONS

We assume that patients with hypothyroidism in HRT have an increased risk of BPPV recurrence, which is particularly strong for patients with HT and positive thyroid antibodies, suggesting an association between autoimmunity and recurrent vertigo.

Shared etiology of type 1 diabetes and Hashimoto's thyroiditis: a population-based twin study

OBJECTIVE

Type 1 diabetes and Hashimoto's thyroiditis frequently cluster in individuals and in families, indicating shared origins. The objective of this study was to investigate familial co-aggregation of these diseases and to quantify shared genetic and environmental factors.

DESIGN

This study is a twin cohort study.

METHODS

National health registers were used to identify cases among 110 814 Swedish twins. Co-aggregation was calculated as risk ratios for type 1 diabetes among co-twins of individuals with Hashimoto's thyroiditis, and vice-versa. Variance explained by genetics (i.e. heritability), and the proportions thereof shared between the diseases, was estimated by contrasting associations in monozygotic and dizygotic twins using structural equation models.

RESULTS

Individuals with one disease were at a high risk for the other disease (adjusted risk ratio: 11.4 (95% CI: 8.5-15.3)). Co-aggregation was more common in monozygotic than in dizygotic pairs, with adjusted risk ratios of 7.0 (95% CI: 3.2-15.1) and 1.7 (95% CI: 0.7-4.1), respectively. Genetic effects shared across diseases accounted for 11% of the variance for type 1 diabetes and 9% of the variance for Hashimoto's thyroiditis, while environmental factors unique to individual twins, but shared across diseases, accounted for 10% of the variance for type 1 diabetes and 18% of the variance for Hashimoto's thyroiditis.

CONCLUSIONS

Both genes and environment unique to individual twins contribute to considerable etiologic overlap between type 1 diabetes and Hashimoto's thyroiditis. These findings add to the current knowledge on the mechanisms behind autoimmune disease clustering and could guide future research aimed at identifying pathophysiological mechanisms and intervention targets.

T4+T3 Combination Therapy: An Unsolved Problem of Increasing Magnitude and Complexity

Thyroxine (T4)+triiodothyronine (T3) combination therapy can be considered in case of persistent symptoms despite normal serum thyroid stimulating hormone in levothyroxine (LT4)-treated hypothyroid patients. Combination therapy has gained popularity in the last two decades, especially in countries with a relatively high gross domestic product. The prevalence of persistent symptoms has also increased; most frequent are complaints about energy levels and fatigue (80% to 90%), weight management (70% to 75%), memory (60% to 80%), and mood (40% to 50%). Pathophysiological explanations for persistent problems are unrealistic patient expectations, comorbidities, somatic symptoms, related disorders (Diagnostic and Statistical Manual of Mental Disorders [DSM-5]), autoimmune neuroinflammation, and low tissue T3. There is fair circumstantial evidence for the latter cause (tissue and specifically brain T3 content is normalized by T4+T3, not by T4 alone), but the other causes are viewed as more relevant in current practice. This might be related to the 'hype' that has emerged surrounding T4+T3 therapy. Although more and better-designed trials are needed to validate the efficacy of T4+T3 combination, the management of persistent symptoms should also be directed towards alternative causes. Improving the doctor-patient relationship and including more and better information is crucial. For example, dissatisfaction with the outcomes of T4 treatment for subclinical hypothyroidism can be anticipated as recent trials have demonstrated that LT4 is hardly effective in improving symptoms associated with subclinical hypothyroidism.

Liothyronine and levothyroxine prescribing in England: A comprehensive survey and evaluation

INTRODUCTION

The approach to thyroid hormone replacement varies across centres, but the extent and determinants of variation is unclear. We evaluated geographical variation in levothyroxine (LT4) and liothyronine (LT3) prescribing across General Practices in England and analysed the relationship of prescribing patterns to clinical and socioeconomic factors.

METHODS

Data was downloaded from the NHS monthly General Practice Prescribing Data in England for the period 2011-2020.

RESULTS

The study covered a population of 19.4 million women over 30 years of age, attending 6,660 GP practices and being provided with 33.7 million prescriptions of LT4 and LT3 at a total cost of £90million/year. Overall, 0.5% of levothyroxine treated patients continue to receive liothyronine. All Clinical Commission Groups (CCGs) in England continue to have at least one liothyronine prescribing practice and 48.5% of English general practices prescribed liothyronine in 2019-2020. Factors strongly influencing more levothyroxine prescribing (model accounted for 62% of variance) were the CCG to which the practice belonged and the proportion of people with diabetes registered on the practice list plus antidepressant prescribing, with socioeconomic disadvantage associated with less levothyroxine prescribing. Whereas factors that were associated with increased levels of liothyronine prescribing (model accounted for 17% of variance), were antidepressant prescribing and % of type 2 diabetes mellitus individuals achieving HbA1c control of 58 mmol/mol or less. Factors that were associated with reduced levels of liothyronine prescribing included smoking and higher obesity rates.

CONCLUSION

In spite of strenuous attempts to limit prescribing of liothyronine in general practice a significant number of patients continue to receive this therapy, although there is significant geographical variation in the prescribing of this as for levothyroxine, with specific general practice and CCG-related factors influencing prescribing of both levothyroxine and liothyronine across England.

Presence of risk factors for thyroid cancer does not improve the performance of ultrasound screening for thyroid nodules in patients with obesity

PURPOSE

It has been suggested, on a theoretical basis, that ultrasound screening of thyroid nodules in obese patients with additional risk factors (family history, chronic autoimmune thyroiditis or high thyrotropin) might be cost-effective for the early detection and treatment of thyroid cancer. The present study evaluates if this approach can be validated in a real clinical setting.

METHODS

Patients with obesity who attended hospital-based clinics were evaluated for risk factors of thyroid cancer and ultrasound screened for thyroid nodularity. Detected nodules were evaluated according to current guidelines.

RESULTS

A total of 429 patients were evaluated (70.2% women, mean age 49.1 ± 11.0, mean body mass index 42.6 ± 5.8 kg/m² ). Risk factors were present in 129 (30.1%) patients. Thyroid nodules with indication for fine-needle aspiration biopsy were detected in 69 (16.1%). We did not find differences in the risk of harbouring thyroid nodules according to the presence of risk factors (no risk factors 16.6%, risk factors 14.1%, P = .64). No single risk factor conferred an increased risk for thyroid nodules During the screening procedure, four cases of thyroid cancer were detected, none of them with the evaluated risk factors.

CONCLUSION

The presence of known risk factors for thyroid cancer does not improve the performance of a US screening strategy aimed at the detection of thyroid nodules in obese patients. According to current guidelines, screening for thyroid nodules in obese patients is not recommended regardless of the presence of thyroid cancer risk factors.

The Burden of Hormonal Disorders: A Worldwide Overview With a Particular Look in Italy

Endocrine diseases have a considerable impact on public health from an epidemiological point of view and because they may cause long-term disability, alteration of the quality-of-life of the affected patients, and are the fifth leading cause of death. In this extensive review of the literature, we have evaluated the prevalence of the different disorders of endocrine interest in the world and Italy, highlighting their epidemiological, clinical, and economic impact.

Analyses of the Relation between BPPV and Thyroid Diseases: A Nested Case-Control Study

BACKGROUND

This study investigated relationship between multiple thyroid disorders and benign paroxysmal positional vertigo (BPPV), adjusting for levothyroxine medication.

METHODS

The Korean National Health Insurance Service-Health Screening Cohort data from 2002 to 2015 were used. A total of 19,071 patients with BPPV were matched with 76,284 participants of a control group in a ratio of 1:4 for age, sex, income, and region of residence. The previous histories of thyroid disorders such as goiter, hypothyroidism, thyroiditis, hyperthyroidism, and autoimmune thyroiditis were investigated in both the BPPV and control groups. The odds ratios (ORs) for BPPV in thyroid diseases were calculated using conditional logistic regression analyses.

RESULTS

The histories of goiter (5.5% vs. 4.1%), hypothyroidism (4.7% vs. 3.7%), thyroiditis (2.1% vs. 1.6%), and hyperthyroidism (3.1% vs. 2.5%) were higher in the BPPV group than in the control group (all p < 0.001). Goiter, hypothyroidism, thyroiditis, and hyperthyroidism were associated with BPPV (adjusted OR = 1.28 (95% CI = 1.17-1.39) for goiter, 1.23 (95% CI = 1.10-1.37) for hypothyroidism, 1.13 (95% CI = 1.02-1.26) for hyperthyroidism, each p < 0.05).

CONCLUSIONS

BPPV was associated with thyroid disorders such as goiter, hypothyroidism, thyroiditis, and hyperthyroidism.

Incidence, prevalence and mortality of systemic sclerosis in Italy: a nationwide population-based study using administrative health data

To study incidence, prevalence and mortality of systemic sclerosis (SSc) in Italy, assessing epidemiological differences between men and women and in distinct age groups. We performed a nationwide population-based study using administrative health data from regional co-payment exemption registries. Patients entitled with SSc-specific co-payment exemption were included. Fourteen of the 20 Italian regions contributed data covering a population of over 45 million individuals. Crude annual incidence rate, annual prevalence, crude annual mortality rate and standardised mortality ratio (SMR) were calculated. In 2016, the overall crude incidence rate of SSc was 18.5 (95% CI 16.9-20.2) per million per year. Incidence rate was 31.0 (95% CI 28.1-34.1) per million in women, and 4.3 (95% CI 3.2-5.6) per million in men. Peak incidence was observed in the age range 55-69 years. Overall annual prevalence was 306.1 (95% CI 301.1-311.2) per million. Prevalence was 530.8 (95% CI 521.5-540.2) per million in women and 67.8 (95% CI 64.4-71.3) per million in men, with a female to male ratio of 7.8:1. Highest prevalence was observed in the range 70-84 years. Crude annual mortality rate was 27.9 (95% CI 24.9-31.1) per 1000 patients. Overall SMR in patients with SSc was 2.8 (95% CI 1.9-3.8). SMR was 3.8 (95% CI 2.9-5.1) in men and 2.6 (95% CI 1.8-3.6) in women. We provided updated estimates on epidemiology of SSc in Italy. Our findings on incidence, prevalence and mortality of SSc are consistent with previously published literature.

The Effect of Hypothyroidism on Bone Loss at Dental Implants

Hypothyroidism (HT) is an endocrine disorder characterized by abnormally reduced thyroid gland activity and is most commonly of autoimmune etiology. HT is associated with alterations in bone metabolism, and HT patients typically experience decreased bone resorption. The objective of this study was to use dental implants as standardized reference markers to compare the extent of alveolar bone loss in implant patients with and without HT. We examined medical and dental history records and radiographic data from 635 patients receiving 1480 implants during 2000–2017. The rate of bone loss was calculated from differences in radiographic bone levels over time, corrected for radiographic distortion. Peri-implant bone loss from patients with HT was significantly lower than for those without HT (t1252= −3.42; 95% confidence interval= 0.47–1.73; P &lt; .001; M = 0.53 and 1.63 mm/yr, respectively). A similar relationship persisted after excluding smokers and diabetics and after additionally excluding those on systemic steroids, hormone replacement therapy, hormone medications, or autoimmune diseases other than HT. Our data suggest that patients with HT have a decreased rate of bone loss around dental implants and may not be at increased risk for dental implant failure. The decreased bone metabolic rate among patients with HT might contribute to those findings.

Incidence and prevalence of hyperthyroidism: a population-based study in the Piedmont Region, Italy

PURPOSE

Unrecognized and untreated hyperthyroidism leads to serious clinical complications with adverse outcomes for patients and increasing costs for the health care system. Hence, adequate knowledge of the epidemiological features of such condition is desirable to plan effective interventions. The aim of our study was to estimate incidence and prevalence of hyperthyroidism in the mildly iodine-deficient Italian Region of Piedmont.

METHODS

A retrospective cohort study was conducted using Administrative Health Databases of the Piedmont Region, Italy (2012-2018). Hyperthyroidism cases were defined as the subjects who had at least one of the following claims: (i) hospital discharge records with hyperthyroidism diagnosis code; (ii) exemption from co-payment for hyperthyroidism; (iii) prescription of one of the following medications: methimazole, propylthiouracil, or potassium perchlorate.

RESULTS

The overall prevalence was 756 per 100,000 inhabitants [95% CI 748-764], and the overall incidence was 81 per 100,000-person year [95% CI 80-82]. The prevalence and incidence increased with age and were two-fold higher among women than men. Women also showed two distinct peaks in incidence at the age of 30 and 50; after the age of 60, the trend became similar between sexes. With regard to the geographic distribution, an increasing gradient of incidence was observed from the northern to the south-western areas of the Region.

CONCLUSION

This is the first Italian study based on health databases to estimate the incidence and prevalence of hyperthyroidism in the general population. This approach can represent an inexpensive and simple method to monitor patterns of hyperthyroidism in iodine-deficient areas.

Hypothyroidism and Kidney Function: A Mendelian Randomization Study

Background: Uncertainty in the mechanism and directionality of observational associations between thyroid function and kidney function may be addressed by genetic analysis with an instrumental variable method termed bidirectional Mendelian randomization (MR). Methods: In the Women's Genome Health Study (WGHS), observational associations between thyroid measures and kidney function were evaluated. Genetic instruments for MR were from recent genome-wide association studies (GWAS) of hypothyroidism, thyrotropin (TSH), and free thyroxine (fT4) concentrations within the reference range, thyroid peroxidase antibodies (TPOAb), estimated glomerular filtration rate from creatinine (eGFR_crea), eGFR from cystatin C (eGFR_cys), and chronic kidney disease (CKD). In WGHS individual-level data, these instruments were used for bidirectional MR between thyroid (N = 3336) and kidney (N = 23,186) functions. To increase power, MR was also performed using GWAS summary statistics from the Chronic Kidney Disease Genetics Consortium (CKDGen) for eGFR_crea (N = 567,460), eGFR_cys (N = 24,063), CKD [N(total) = 480,698, N(cases) = 41,395], and urinary albumin/creatinine ratio (UACR/N = 54,450). Results: In the WGHS, hypothyroidism was observationally associated with decreased eGFR_crea [beta (standard error, SE): -0.024 (0.009) ln(mL/min/1.73 m²), p = 0.01]. By MR, hypothyroidism was associated with decreased eGFR_crea in the WGHS [beta (SE): -0.007 (0.002) per doubled odds hypothyroidism, p = 1.7 × 10^-3] and in CKDGen [beta (SE): -0.004 (0.0005), p = 2.0 × 10^-22], and robust to sensitivity analysis. Hypothyroidism was also associated by MR with increased CKD in CKDGen (odds ratio, OR [confidence interval, CI]: 1.05 [1.03-1.08], p = 3.3 × 10^-5), but not in the WGHS (OR [CI]: 1.02 [0.95-1.10], p = 0.57). Increased TSH within the reference range had an MR association with increased eGFR_crea in the WGHS [beta (SE): -0.018 (0.007) ln(mL/min/1.73 m²)/standard deviation, SD, p = 6.5 × 10^-3] and CKDGen [beta (SE): -0.008 (0.001) ln(mL/min/1.73 m²)/SD, p = 6.8 × 10^-17], and with CKD in CKDGen (OR [CI]: 1.10 [1.04-1.15], p = 3.1 × 10^-4). There were no MR associations of hypothyroidism or TSH with eGFR_cys or UACR, and MR associations of fT4 in the reference range with kidney function were inconsistent in both the WGHS and CKDGen. However, by MR in CKDGen, TPOAb were robustly associated with decreased eGFR_crea [beta (SE): -0.041 (0.009), p = 6.2 × 10^-6] and decreased eGFR_cys [beta (SE): -0.294 (0.065), p = 6.2 × 10^-6]. TPOAb were less robustly associated with CKD but not associated with UACR. In reverse MR in the WGHS, kidney function was not consistently associated with thyroid function. Conclusions: Bidirectional MR supports a directional association from hypothyroidism, increased TSH, and TPOAb, but not fT4, to decreased eGFR_crea and increased CKD.

Prevalence of Undiagnosed Hypothyroidism in Europe: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with undiagnosed hypothyroidism are not treated for the disease and are at high risk of developing serious complications, with major impact on public health. There is a need to systematically review the available evidence on this topic.

OBJECTIVE

To identify the prevalence of undiagnosed hypothyroidism in Europe.

METHODS

A systematic review of the literature (Medline, EMBASE, and Cochrane Central) was performed to identify epidemiological studies on the prevalence of undiagnosed hypothyroidism among European populations published between January 2008 and April 2018. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Random-effects meta-analyses were performed to pool estimates of proportions (with 95% confidence intervals [CIs]) of undiagnosed (1) subclinical, (2) overt, and (3) total hypothyroidism.

RESULTS

The search returned 15,565 citations (4,526 duplicates). Twenty papers were included in the study. Fourteen and 6 studies were of good and moderate methodological quality, respectively. The results of the meta-analyses were as follows for the prevalence of undiagnosed hypothyroidism: subclinical, 4.11% (95% CI 3.05-5.31%, I2 = 99.32%); overt, 0.65% (95% CI 0.38-0.99%, I2 = 96.67%); and total, 4.70% (95% CI 2.98-6.79%, I2 = 99.53%). According to the sensitivity analysis, the prevalence of hypothyroidism tends to be higher in female patients, in those aged ≥65 years, among studies with lower sample sizes, in those with thyroid-stimulating hormone levels <4.5 mIU/L, and in Eastern and Southern Europe.

CONCLUSIONS

The current evidence suggests that a considerable proportion of the European population has hypothyroidism, particularly subclinical hypothyroidism, which is undiagnosed. This issue deserves further investigation because of possible deleterious consequences for public health.

Adherence to thyroid hormone replacement therapy: a retrospective, claims database analysis

OBJECTIVE

The objective of this analysis was to compare adherence at 6 months and 12 months across levothyroxine formulations for patients with hypothyroidism.

METHODS

This retrospective analysis utilized insurance claims data from a commercially insured population from January 1, 2000 through March 31, 2016. Patients were included if they were diagnosed with hypothyroidism and initiated treatment with generic levothyroxine, Levoxyl, Synthroid, Unithroid, or Tirosint. Patients were excluded if they were younger than age 18, were diagnosed with thyroid cancer, received a prescription for liothyronine, or did not have continuous insurance coverage over the study period. Adherence, defined by the proportion of days covered (PDC) ≥ 80%, was examined using multivariable analyses for both 6 and 12 months post-initiation on therapy Results: The study identified 580,331 patients who fit the study criteria. At 6 months, 40.3% of patients were found to be non-adherent, while 51.9% were non-adherent at 12 months. Synthroid was associated with significantly higher adherence compared to all other levothyroxine formulations at both 6 and 12 months. Compared to generic levothyroxine, the likelihood of being adherent at 12 months was highest for Synthroid (OR = 1.44; 95% CI = 1.43-1.46), followed by Levoxyl (OR = 1.20 95% CI = 1.17-1.23). Tirosint and Unithroid were associated with significantly lower adherence at 12 months compared to generic levothyroxine (OR = 0.65; 95% CI = 0.57-0.75 and OR = 0.79; 95% CI = 0.71-0.89, respectively).

CONCLUSIONS

This large, retrospective real-world study demonstrated that adherence to levothyroxine remains a concern among patients with hypothyroidism, and that differences in adherence may exist across levothyroxine formulations.

Evidence of earlier thyroid dysfunction in newly diagnosed oral lichen planus patients: a hint for endocrinologists

The association between oral lichen planus (OLP) and hypothyroidism has been debated with conflicting results: some authors detected a statistically significant association between these two, while others did not confirm it. The aim of this study was to evaluate the thyroid status in patients with newly diagnosed OLP to test the null hypothesis that thyroid disease is not associated with an increased incidence of oral lesions, with a prospective case-control approach. A total of 549 patients have been evaluated, of whom 355 were female. Odds ratio (OR) and 95% confidence intervals (CIs) were obtained. Patients suffering from thyroid diseases were associated with an almost 3-fold increased odds of having OLP (OR 2.85, 95% CI: 1.65-4.94), after adjusting this analysis for age, gender, body mass index, smoking status, diabetes, hypertension and hepatitis C infection. It would be appropriate to further investigate the possible concomitance of OLP among patients with thyroid disorder; endocrinologists should be aware of this association, especially because OLP is considered a potentially malignant oral disorder.