Levothyroxine dose and fracture risk according to the osteoporosis status in elderly women

Evaluation of Bone Health in Postmenopausal Women Using Long-Term Levothyroxine Treatment Due to Post-Procedural Hypothyroidism

Purpose

The connection between thyroid disorders and the health of bone is an endocrinological dilemma for physicians. Several studies have been conducted to examine the correlation between levothyroxine use and the risk of fracture. Different results have been obtained in these studies. The objective of the present study is to evaluate the impact of prolonged thyroid hormone replacement therapy on bone health in postmenopausal women.

Patients and Methods

We obtained demographic data, laboratory results, and anthropometric measurements of patients from the hospital database. After the exclusion of patients, 59 patients with post-procedural hypothyroidism (n = 59) and a control group (n = 45) were evaluated. The patient group consisted of individuals who had undergone thyroid surgery for a benign condition and had been on levothyroxine treatment for a minimum of 5 years. Densitometric measurements of bone mass in the hip and spine were performed by bone mineral densitometry.

Results

Groups were similar in age, PTH, vitamin D, bone-specific ALP, and BMI (p>0.05). The control group had a significantly lower total T score-F than the hypothyroidism group (-0.77±1.3 to -0.29±1.02, p= 0.041). However, total T score-LV, total gr/cm2-LV, and total gr/cm2-F were similar in both groups.

Conclusion

This study showed that long-term levothyroxine therapy, which aims to maintain TSH levels within the normal reference range, is associated with increased bone mineral density (BMD) in postmenopausal women compared with the control group. Thus, to maintain bone health and prevent osteoporosis, it is important that postmenopausal women on long-term levothyroxine replacement undergo medical follow-up to prevent TSH suppression.

Hypopituitarism and bone disease: pathophysiology, diagnosis and treatment outcomes

Hypopituitarism is a rare but significant endocrine disorder characterized by the inadequate secretion of one or more pituitary hormones. The intricate relationship between hypopituitarism and bone health is a topic of growing interest in the medical community. In this review the authors explore associations between hypopituitarism and bone health, with specific examination of the impact of growth hormone deficiency, central hypogonadism, central hypocortisolism, and central hypothyroidism. Pathogenesis, diagnosis, and treatment options as well as challenges posed by osteopenia, osteoporosis, and fractures in hypopituitarism are discussed.

Refractory hypothyroidism in children: an overview

Refractory hypothyroidism (RF) defined as raised serum levels of thyroid stimulating hormone (TSH) above upper limit of the reference range with or without the persistence of hypothyroid symptoms following a 6-week interval after the dosage was last increased to upper limits of dose per age. The most common cause of RH is inadequate compliance. In addition, diet, concomitant medication interactions, and gastrointestinal diseases can all result in l-thyroxine (LT4) malabsorption, which can cause RH. Moreover, weight gain, switching brands of LT4, poor storage of LT4, chronic liver disorders, cystic fibrosis, nephrotic syndrome, consumptive hypothyroidism, Addison's disease are significant contributors to RF in children. RH in children is frequently asymptomatic, when symptoms do occur, they are typically minor and resemble those of hypothyroidism. It is essential to identify RH early and treat its underlying cause in order to avoid overusing LT4, which can lead to cardiac and bone problems. Endocrinologists should handle children who they suspect of having RH methodically after making sure there is enough compliance. Searching for undiagnosed illnesses and/or other factors that can affect LT4 absorption could be part of this. We present this review after an extensive literature search and long-standing clinical experience. This review's objective is to shed light on the causes, clinical manifestations, investigations, and treatment of RH in children.

Association Between Periodontal Diseases and Hypothyroidism: A Case-Control Study

Objective

Periodontal diseases are chronic inflammatory disorders influenced by systemic health of the individual. This study aimed to investigate the association between hypothyroidism and periodontal disease in a cohort of adult Saudi population.

Methods

This case-control study included 201 adults with hypothyroidism on hormone replacement therapy and 188 healthy controls. The medical files of patients were reviewed to check thyroid stimulation hormone (TSH) and free thyroxine (FT4) levels. Participants completed a questionnaire on demographic and health information, followed by a comprehensive periodontal examination. Pearson chi-square and binary logistic regression analyses determined associations, with a significance set at p ≤0.05.

Results

Gingivitis was found in 20.9% of cases and 58% of controls. Periodontitis stages I, II, III and IV were in general higher in cases compared to controls (23.4%, 27.9%, 21.9%, 6% in cases versus 13.8%, 17%, 9.6%, 1.6% in controls, respectively). Mean PPD and CAL values were higher in cases (5.54 ± 2.5 and 3.88 ± 3.1) than in controls (4.03 ± 1.6 and 1.72 ± 2.4). Significant associations between periodontal status and hypothyroidism were found (p < 0.0001). The periodontal status in hypothyroid cases correlated significantly with hormone replacement therapy dose and duration (p < 0.0001).

Conclusion

The findings of the current study showed that, in a cohort of adult Saudi subjects, patients with hypothyroidism have higher prevalence and more severe periodontal disease symptoms compared to controls, suggesting significant association.

Diversity of the diet is correlated with osteoporosis in post-menopausal women: an Iranian case-control study

Background

Proper nutrition is a crucial factor in preventing osteoporosis, a significant pathological cause linked to skeletal weakness; this study investigated the relationship between dietary diversity score and food group diversity score with osteoporosis in postmenopausal women.

Methods

This case-control study was conducted on 378 menopausal women aged 45-85 in Tehran, Iran. The age-matching method to control the confounding effect of age was used. The method of dual-energy X-ray absorptiometry (DXA) was used for assessing the bone mineral density of lumbar vertebrae and femoral neck. The bone mass status was evaluated with WHO criteria. All subjects were divided into the osteoporosis group and the non-osteoporosis group according to their T-score. A convenience sampling method was utilized to select the participants, which included two groups: case (n = 189) and control (n = 189). Data was collected using demographic and anthropometric information questionnaires, a valid 147 item food frequency questionnaire, and a physical activity questionnaire. Statistical analyses were conducted using SPSS-26, and p-values less than 0.05 were deemed to be statistically significant.

Results

The results indicated significant differences in weight, body mass index, physical activity, smoking, and alcohol use between the two groups. The mean ± standard deviation of dietary diversity score (DDS) was lower in participants with osteoporosis (case) (3.31 ± 1.26) than in control (4.64 ± 1.33) (p < 0.001). The mean ± standard deviation of diversity score of cereals, fruits, and vegetables in the osteoporosis group (respectively: 0.71 ± 0.21, 0.94 ± 0.76, and 0.45 ± 0.44) was less than the control group (respectively: 0.80 ± 0.21, 1.64 ± 0.55 and 0.87 ± 0.42) (p < 0.001). After adjusting the confounding variables, the risk of osteoporosis had an inverse relationship with the diversity score of vegetable (OR = 0.16; 95%CI: 0.07-0.35), bread and cereal (OR = 0.21; 95% CI: 0.05-0.87) and fruit (OR = 0.35; 95%CI: 0.22-0.56) (p < 0.05). Nevertheless, no discernible correlation was seen between the tertiles of DDS, dairy and meat diversity score, and osteoporosis.

Conclusion

We found a correlation between the diversity score of fruits, vegetables, and grains and osteoporosis. However, there is no significant correlation between the DDS triads and the diversity score of dairy products and meats with osteoporosis.

Diagnosis and therapeutic approach to bone health in patients with hypopituitarism

The results of many studies in recent years indicate a significant impact of pituitary function on bone health. The proper function of the pituitary gland has a significant impact on the growth of the skeleton and the appearance of sexual dimorphism. It is also responsible for achieving peak bone mass, which protects against the development of osteoporosis and fractures later in life. It is also liable for the proper remodeling of the skeleton, which is a physiological mechanism managing the proper mechanical resistance of bones and the possibility of its regeneration after injuries. Pituitary diseases causing hypofunction and deficiency of tropic hormones, and thus deficiency of key hormones of effector organs, have a negative impact on the skeleton, resulting in reduced bone mass and susceptibility to pathological fractures. The early appearance of pituitary dysfunction, i.e. in the pre-pubertal period, is responsible for failure to achieve peak bone mass, and thus the risk of developing osteoporosis in later years. This argues for the need for a thorough assessment of patients with hypopituitarism, not only in terms of metabolic disorders, but also in terms of bone disorders. Early and properly performed treatment may prevent patients from developing the bone complications that are so common in this pathology. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary disease.

Refractory Hypothyroidism: Unraveling the Complexities of Diagnosis and Management

INTRODUCTION

Refractory hypothyroidism (RH) represents a challenge in the diagnosis and treatment within the field of thyroidology. It is defined as the inability to achieve disease control despite using levothyroxine (LT4) doses of 1.9 μg/kg/d or higher.

METHODS

A comprehensive review, encompassing 103 articles, was conducted using the Scielo, Scopus, and EMBASE databases, providing an approach to evaluation and diagnosis of this condition.

RESULTS

LT4 disintegrates and dissolves within an acidic gastric environment before being absorbed in the jejunum and ileum. It then extensively binds to serum transporter proteins and undergoes deiodination to yield tri-iodothyronine, the biologically active hormone. There are various nonpathological causes of RH, such as noncompliance with treatment, changes in the brand of LT4, food and drug interferences, as well as pregnancy. Pathological causes include lactose intolerance, Helicobacter pylori infection, giardiasis, among others. The diagnosis of RH involves conducting a thorough medical history and requesting relevant laboratory tests to rule out causes of treatment resistance. The LT4 absorption test allows for the identification of cases of malabsorption. The treatment of RH involves identifying and addressing the underlying causes of noncompliance or malabsorption. In cases of pseudomalabsorption, supervised and weekly administration of LT4 may be considered.

DISCUSSION

Early recognition of RH and correction of its underlying cause are of utmost importance, as this avoids the use of excessive doses of LT4 and prevents cardiovascular and bone complications associated with this condition.

Assessing the cardiovascular effects of levothyroxine use in an ageing United Kingdom population (ACEL-UK) protocol: a cohort and target trial emulation study

BACKGROUND

Subclinical hypothyroidism is diagnosed when serum thyroid stimulating hormone levels are higher whilst free thyroxine levels remain within their respective reference ranges. These reference ranges are uniformly applied in all adults, despite serum thyroid stimulating hormone levels naturally increasing with age. Research has found that mildly elevated thyroid stimulating hormone levels may be associated with some benefits in ageing patients, including reduced mortality and better cardiorespiratory fitness. Levothyroxine is typically prescribed to patients with hypothyroidism, but no conclusive evidence exists on whether levothyroxine therapy is beneficial or detrimental in older subclinical hypothyroid patients. Despite this, prescriptions for levothyroxine are increasing year-on-year. This study aims to determine if receiving levothyroxine affects the cardiovascular and bone health outcomes of subclinical patients in primary care aged 50 years and over.

METHODS

This project includes a retrospective cohort analysis and a target trial emulation study using electronic patient records collected between 2006 and 2021 and recorded in The Health Improvement Network database. The primary outcome of this study is to compare the cardiovascular outcomes of subclinical hypothyroid patients aged over 50 years treated with levothyroxine compared to those untreated. Secondary outcomes are bone health and all-cause mortality outcomes. Descriptive and inferential statistics will both be employed to analyse the data. Secondary analysis will explore confounding factors, including age, sex, smoking status, body mass index, co-morbidities, and levothyroxine dosage.

DISCUSSION

There needs to be a greater understanding of the potential risks of the current treatment for older patients with subclinical hypothyroidism in a primary care setting. We will investigate the clinical importance of this issue and whether older subclinical hypothyroid patients have poorer outcomes when treated. Clarifying this concern may help address the healthcare resource implications of ageing patients being misclassified as having mild hypothyroidism, as these patients are more likely to repeat their blood tests. This could reduce prescription wastage and improve patient outcomes and quality of life in the ageing population.

TRIAL REGISTRATION

Not applicable.

Evaluation and Management of Bone Health in Patients with Thyroid Diseases: A Position Statement of the Korean Thyroid Association

Thyroid hormones play an important physiological role in maintaining adult bone structure and strength. Consequently, thyroid dysfunction is related to skeletal outcomes. Overt hyperthyroidism is an established cause of high bone turnover with accelerated bone loss, leading to osteoporosis and increased fracture risk. Hyperthyroidism induced by thyroid-stimulating hormone-suppressive therapy in patients with differentiated thyroid cancer is a cause of secondary osteoporosis. In contrast, there is a lack of evidence on the negative impact of hypothyroidism on bone health. Considering the clinical updates on the importance of bone health in thyroid dysfunction, the Task Force from the Clinical Practice Guidelines Development Committee of the Korean Thyroid Association recently developed a position statement on the evaluation and management of bone health of patients with thyroid diseases, particularly focused on endogenous hyperthyroidism and thyroid-stimulating hormone-suppressive therapy-associated hyperthyroidism in patients with differentiated thyroid cancer. Herein, we review the Korean Thyroid Association's position statement on the evaluation and management of bone health associated with thyroid diseases.

Understanding Worry About Risks Associated With Thyroid Hormone Therapy: A National Survey of Endocrinologists, Family Physicians, and Geriatricians

OBJECTIVE

Thyroid hormone use is widespread, and prior studies have shown that over- and undertreatment with thyroid hormone are common. Our objective was to understand physician worry regarding risks associated with thyroid hormone therapy, specifically overtreatment or undertreatment.

METHODS

A nationwide survey was administered to physician members of the Endocrine Society, the American Academy of Family Practice, and the American Geriatrics Society. Participants were asked how often they were worried about various risks that may be associated with thyroid hormone over- or undertreatment, that is, cardiovascular complications, bone complications, and poor quality of life due to overtreatment or undertreatment with thyroid hormone. Multivariable regression analyses were conducted to determine physician characteristics associated with each worry.

RESULTS

The response rate was 63% (359 of 566); of those who responded, 128 (36%) were primary care physicians, 114 (32%) were endocrinologists, and 113 (32%) were geriatricians. Overall, 74 (21%) physicians reported that they frequently or always worried about cardiovascular complications, 74 (21%) about bone complications, 111 (31%) about the poor quality of life due to symptoms from undertreatment with thyroid hormone, and 87 (24%) about the poor quality of life due to symptoms from overtreatment with thyroid hormone. Endocrinologists were more likely to frequently or always worry about the patients' poor quality of life due to symptoms from overtreatment (odds ratio, 2.05; 95% confidence interval, 1.09-3.93) compared with primary care physicians.

CONCLUSION

Up to one third of the physicians frequently or always worried about risks resulting from the thyroid hormone overtreatment or undertreatment. More research is needed across specialties to understand physician perceptions of how thyroid hormone therapy impacts the patients' quality of life.

Systemic medicines taken by adult special care dental patients and implications for the management of their care

Introduction Significant changes have taken place in the profile of prescription medicines being taken by the adult UK population over the last decade. The aims of this article are to review the literature to understand the overall trends and underlying factors, and then to compare this with the medication profile of a cohort of adult special care dental (SCD) patients. Materials and method Five hundred patient records were examined and retrospective data on systemic medicines being taken were obtained and classified according to the index used in the British National Formulary (BNF).Results The results revealed a high level of polypharmacy with 57% of SCD patients taking three or more medicines compared to 24% of the population in England. Antiepileptic drugs were the most frequently taken group of medicines (42%), followed by antidepressants (39.7%) and antipsychotics (37.6%). Conclusions Our results demonstrate the medical complexity of patients in this cohort and enable clinicians to increase their familiarity with the most commonly taken medicines and the tools available to manage the implications for dental care.

Levothyroxine Therapy in Elderly Patients With Hypothyroidism

Levothyroxine (L-T4) treatment of overt hypothyroidism can be more challenging in elderly compared to young patients. The elderly population is growing, and increasing incidence and prevalence of hypothyroidism with age are observed globally. Elderly people have more comorbidities compared to young patients, complicating correct diagnosis and management of hypothyroidism. Most importantly, cardiovascular complications compromise the usual start dosage and upward titration of L-T4 due to higher risk of decompensating cardiac ischemia and -function. It therefore takes more effort and care from the clinician, and the maintenance dose may have to be lower in order to avoid a cardiac incidence. On the other hand, L-T4 has a beneficial effect on cardiac function by increasing performance. The clinical challenge should not prevent treating with L-T4 should the patient develop e.g., cardiac ischemia. The endocrinologist is obliged to collaborate with the cardiologist on prophylactic cardiac measures by invasive cardiac surgery or medical therapy against cardiac ischemic angina. This usually allows subsequent successful treatment. Management of mild (subclinical) hypothyroidism is even more complex. Prevalent comorbidities in the elderly complicate correct diagnosis, since many concomitant morbidities can result in non-thyroidal illness, resembling mild hypothyroidism both clinically and biochemically. The diagnosis is further complicated as methods for measuring thyroid function (thyrotropin and thyroxine) vary immensely according to methodology and background population. It is thus imperative to ensure a correct diagnosis by etiology (e.g., autoimmunity) before deciding to treat. Even then, there is controversy regarding whether or not treatment of such mild forms of hypothyroidism in elderly will improve mortality, morbidity, and quality of life. This should be studied in large cohorts of patients in long-term placebo-controlled trials with clinically relevant outcomes. Other cases of hypothyroidism, e.g., medications, iodine overload or hypothalamus-pituitary-hypothyroidism, each pose specific challenges to management of hypothyroidism; these cases are also more frequent in the elderly. Finally, adherence to treatment is generally challenging. This is also the case in elderly patients, which may necessitate measuring thyroid hormones at individually tailored intervals, which is important to avoid over-treatment with increased risk of cardiac morbidity and mortality, osteoporosis, cognitive dysfunction, and muscle deficiency.

TSH suppressive therapy and bone

Thyroid hormones stimulate bone turnover in adults by increasing osteoclastic bone resorption. TSH suppressive therapy is usually applied in patients with differentiated thyroid cancer (DTC) to improve the disease outcome. Over the last decades several authors have closely monitored the potential harm suffered by the skeletal system. Several studies and meta-analyses have shown that chronic TSH suppressive therapy is safe in premenopausal women and men. Conversely, in postmenopausal women TSH suppressive therapy is associated with a decrease of bone mineral density, deterioration of bone architecture (quantitative CT, QCT; trabecular bone score, TBS), and, possibly, an increased risk of fractures. The TSH receptor is expressed in bone cells and the results of experimental studies in TSH receptor knockout mice and humans on whether low TSH levels, as opposed to solely high thyroid hormone levels, might contribute to bone loss in endogenous or exogenous thyrotoxicosis remain controversial. Recent guidelines on the use of TSH suppressive therapy in patients with DTC give value not only to its benefit on the outcome of the disease, but also to the risks associated with exogenous thyrotoxicosis, namely menopause, osteopenia or osteoporosis, age >60 years, and history of atrial fibrillation. Bone health (BMD and/or preferably TBS) should be evaluated in postmenopausal women under chronic TSH suppressive therapy or in those patients planning to be treated for several years. Antiresorptive therapy could also be considered in selected cases (increased risk of fracture or significant decline of BMD/TBS during therapy) to prevent bone loss.

The Influence of Thyroid Pathology on Osteoporosis and Fracture Risk: A Review

Thyroid hormones are important factors that regulate metabolism and cell differentiation throughout the human body. A complication of thyroid pathology is represented by an alteration of the bone metabolism which can lead to osteoporosis and fragility fractures, known to have a high mortality rate. Although there is a consensus on the negative impact of hyperthyroidism on bone metabolism, when referring to hypothyroidism, subclinical hypothyroidism, or subclinical hyperthyroidism, there is no general agreement. The aim of our review was to update clinicians and researchers about the current data regarding the bone health in hypothyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism patients. Thyroid disorders have an important impact on bone metabolism and fracture risk, such that hyperthyroidism, hypothyroidism, and subclinical hyperthyroidism are associated with a decreased bone mineral density (BMD) and increased risk of fracture. Subclinical hypothyroidism, on the other hand, is not associated with osteoporosis or fragility fractures, and subclinical hyperthyroidism treatment with radioiodine could improve bone health.

Comparison of the efficacy between once-monthly oral ibandronate and risedronate among Korean women with osteoporosis: a nationwide population-based study

Using a nationwide database from the Korean National Health Insurance Service, this study showed that once-monthly oral ibandronate (150 mg) had better anti-fracture efficacy than once-monthly oral risedronate (150 mg), as seen on assessing overall and non-vertebral fractures among Korean elderly women with osteoporosis.

INTRODUCTION

Once-monthly oral bisphosphonates have been used widely without appropriate comparison. Therefore, we aimed to compare the anti-fracture efficacy of once-monthly ibandronate (150 mg) and once-monthly risedronate (150 mg).

METHODS

We conducted a retrospective cohort study among Korean women aged ≥ 60 years from 2006 to 2015 using a nationwide database from the National Health Insurance Service Senior Cohort. The primary outcome was the first occurrence of fracture related to osteoporosis after the initial prescription of bisphosphonates. A Cox proportional model was used to estimate the incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for overall and site-specific fractures between the two treatments, after adjusting for possible confounding factors.

RESULTS

After propensity score matching, the ibandronate and risedronate groups, with 3454 patients each, were assembled from 36,701 new once-monthly ibandronate or risedronate users. After 4 years of follow-up, the ibandronate group had significantly lower incidence rates of overall and non-vertebral fractures than the risedronate group (IRR 0.822, 95% CI 0.698-0.968, P = 0.919 and IRR 0.798, 95% CI 0.647-0.985, P = 0.036, respectively).

CONCLUSIONS

Once-monthly ibandronate (150 mg) shows better anti-fracture efficacy than once-monthly risedronate (150 mg). However, further large-scale studies are required to confirm our findings and to determine site-specific differences, especially regarding the vertebral and hip areas.

The effect of thyroid functions on osteopenia of prematurity in preterm infants

Background It is known that thyroid hormones have effects on bone development. In particular, the effect of thyroid hormones on osteopenia of prematurity (OOP) has not been examined in preterm infants. Our study aimed to examine the relationship between OOP and congenital hypothyroidism (CH) in preterm infants. Methods Very low birth weight infants (VLBW, <1500 g) were included in the study. Thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels were measured on postnatal day 5. Serum calcium, phosphorus and alkaline phosphatase (ALP) levels were studied as standard screening parameters for OOP at postnatal week 4. Patients with serum ALP level >700 IU/L were included in the OOP group. We intended to figure out the relationship between OOP and CH in infants. Results In our study, OOP frequency was 14.9% among 543 VLBW infants. There was no statistically significant difference between groups with and without CH (21.7% and 14.8%, respectively) in terms of OOP (p=0.632). Gestational age (GA) was significantly lower in infants with diagnosed OOP (p<0.001, p<0.001, respectively). In addition, the prevalence rates of mothers with preeclampsia, small for gestational age (SGA), respiratory support requirement, late-onset neonatal sepsis (LOS), bronchopulmonary dysplasia (BPD) and full enteral feeding time were found to be higher in the OOP group (p<0.05). Conclusions We found that thyroid hormones had no effect on OOP in preterm infants. Therefore, future randomized controlled studies as well as long-term outcome studies are warranted on this topic.

The relationship between subclinical thyroid dysfunction and the risk of fracture or low bone mineral density: a systematic review and meta-analysis of cohort studies

Our aim was to assess the risk of fractures or low bone mineral density (BMD) associated with subclinical thyroid dysfunction among cohorts. We systematically searched Medline (via PubMed), EMBASE, Cochrane Library, Web of Science, CENTRAL and SinoMed up to 31 July 2016 to identify cohort studies which have analyzed associations between subclinical thyroid dysfunction and fracture or BMD. A total of 19 population-based cohorts including 79,368 participants with relationships between subclinical thyroid dysfunction and fractures or BMD were identified as eligible for this meta-analysis. Subclinical hypothyroidism was associated with relative risks (RRs) of 1.34 (95% confidence interval [CI] 1.14, 1.58; I ² = 32%) for hip fracture, 1.27 (95% CI 1.02, 1.58; I ² = 51.9%) for any location of fracture, and 1.25 (95% CI 1.04, 1.50) for forearm fracture. Subclinical hyperthyroidism was associated with RRs of 1.71 (95% CI 1.06, 2.76; I ² = 0.0%) for spine fracture, 1.20 (95% CI 1.03, 1.39; I ² = 0.0%) for non-spine fracture, 1.44 (95% CI 1.21, 1.71; I ² = 0.0%) for hip fracture, and 1.38 (95% CI 1.21, 1.58; I ² = 0.0%) for any location of fracture. Subgroup analysis was conducted according to whether thyroid/anti-thyroid drug users were excluded or not and the results were similar. The change in BMD at the hip (weighted mean difference [WMD] = -0.060, 95% CI -0.116, -0.004; I ² = 0.0%) and femoral neck (WMD = -0.046, 95% CI -0.077, -0.015; I ² = 0.0%) was significantly decreased in the subclinical hyperthyroidism group compared with the euthyroidism groups in females. We failed to find any associations between the change in BMD and subclinical hypothyroidism. The overall quality of evidence was low in all outcomes. Subclinical hyperthyroidism and subclinical hypothyroidism were associated with an increased risk of fractures. Although subclinical hyperthyroidism was related to reduced BMD, no evidence could prove a definite association between subclinical hypothyroidism and the risk of low BMD.

High Prevalence of Radiological Vertebral Fractures in Women on Thyroid-Stimulating Hormone-Suppressive Therapy for Thyroid Carcinoma

CONTEXT

Bone loss and nonvertebral fractures have been reported in patients with differentiated thyroid carcinoma (DTC) undergoing thyroid-stimulating hormone (TSH) suppressive therapy. Radiological vertebral fractures (VFs) are an early and clinically crucial marker of bone fragility.

OBJECTIVE AND DESIGN

A cross-sectional study to evaluate the prevalence and determinants of radiological VFs in women receiving l-thyroxine (L-T4) therapy for DTC.

PATIENTS AND INTERVENTIONS

A total of 179 consecutive women (median age, 59 years; n = 178 postmenopausal) who had undergone thyroidectomy for DTC and were currently receiving L-T4 were evaluated for radiological VFs and bone mineral density (BMD). There were three TSH target levels [<0.5 mU/L, group 1 (n = 83); 0.5 to 1.0 mU/L, group 2 (n = 50); >1.0 mU/L, group 3 (n = 46)].

RESULTS

VFs were found in 51 patients (28.5%), with significantly (P < 0.001) higher prevalence in group 1 (44.6%) as compared with group 2 (24.0%) and group 3 (4.3%). VF prevalence was not significantly different among patients in group 1 with normal BMD, osteopenia, or osteoporosis, whereas in groups 2 and 3, VFs were more frequent in patients with osteoporosis than in those with either osteopenia or normal BMD. In the whole population, VFs were significantly and independently associated with TSH level <1.0 mU/L; densitometric diagnosis of osteoporosis at lumbar spine, femoral neck, or total hip; age of patients; and duration of L-T4 therapy.

CONCLUSION

The prevalence of VFs was high in women with DTC who were undergoing long-term, suppressive L-T4 therapy.

Thyroid Hormone Signaling in the Development of the Endochondral Skeleton

Thyroid hormone (TH) is an established regulator of skeletal growth and maintenance both in clinical studies and in laboratory models. The clinical consequences of altered thyroid status on the skeleton during development and in adulthood are well known, and genetic mouse models in which elements of the TH signaling axis have been manipulated illuminate the mechanisms which underlie TH regulation of the skeleton. TH is involved in the regulation of the balance between proliferation and differentiation in several skeletal cell types including chondrocytes, osteoblasts, and osteoclasts. The effects of TH are mediated primarily via the thyroid hormone receptors (TRs) α and β, ligand-inducible nuclear receptors which act as transcription factors to regulate target gene expression. Both TRα and TRβ signaling are important for different stages of skeletal development. The molecular mechanisms of TH action in bone are complex and include interaction with a number of growth factor signaling pathways. This review provides an overview of the regulation and mechanisms of TH action in bone, focusing particularly on the role of TH in endochondral bone formation during postnatal growth.

MANAGEMENT OF ENDOCRINE DISEASE: l-Thyroxine replacement therapy in the frail elderly: a challenge in clinical practice

The number of elderly people, mostly aged over 85 years (the 'oldest old'), is increasing worldwide. As a consequence, accompanying morbidity and disability have been increasing, and frailty, defined as an age-related condition of decline of physiological reserves and vulnerability, represents an emerging problem. Caring for older frail people may represent a challenge, since the elderly differ significantly from younger adults in terms of comorbidity, polypharmacy, pharmacokinetics and greater vulnerability to adverse drug reactions. Specific criteria of therapeutic appropriateness and modified goals of care are needed in such patients, also in endocrine care settings. Indeed, thyroid dysfunctions are among the most common conditions in older, multimorbid populations. The prevalence of overt and subclinical hypothyroidism is as high as 20% and thyroid hormone prescription is common in the elderly, with a trend toward levothyroxine treatment of more marginal degrees of hypothyroidism. In addition, older patients have the highest rate of overtreatment during replacement therapy and are more susceptible to developing adverse effects from thyroid hormone excess. Recently, results of a multicentric randomized controlled trial, the TRUST-IEMO collaboration trial, added further insights to the debated question of whether and when levothyroxine treatment is required and if it is beneficial in the elderly. With this in mind, we revised the relevant literature on the impact of thyroid dysfunction and replacement therapy among older people, with the aim to better define indications, benefits and risks of l-T4 replacement therapy in the frail elderly.

Comparative clinicopathological and outcome analysis of differentiated thyroid cancer in Saudi patients aged below 60 years and above 60 years

INTRODUCTION

The aim of this study was to evaluate the treatment outcomes of differentiated thyroid cancer in Saudi patients aged above 60 years.

MATERIALS AND METHODS

Comparative analysis was performed in 252 patients aged 46-60 years (Group A) and 118 patients aged above 60 years (Group B), who had thyroidectomy, radioactive iodine-131, and thyroid-stimulating hormone suppression therapy between July 2000 and December 2012. Different clinicopathological features, treatment, complications, disease-free survival, and overall survival rates were compared.

RESULTS

Mean age of patients in Group A was 51.9 years (range: 46-60), and mean age of those in Group B was 68.6 years (range: 62-97). Group B patients had higher positive lymph nodes (43.2%), P=0.011. The frequency of extrathyroidal extension, multifocality, and lymphovascular space invasion was seen more in Group B than in Group A. Postsurgical complications (permanent hypoparathyroidism, bleeding, and wound infections) were also seen more in Group B (P=0.043, P=0.011, and P=0.021, respectively). Group B patients experienced more locoregional recurrences (11.0%, P=0.025); similarly, more distant metastases were observed in Group B (15.3%, P=0.003). The 10-year disease-free survival rates were 87.6% in Group A and 70.8% in Group B (P<0.0001).

CONCLUSION

Differentiated thyroid cancer in patients aged above 60 years are more aggressive biologically and associated with a worse prognosis, and the morbidity is significantly high as compared to patients aged below 60 years.

Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

The skeleton is an exquisitely sensitive and archetypal T3-target tissue that demonstrates the critical role for thyroid hormones during development, linear growth, and adult bone turnover and maintenance. Thyrotoxicosis is an established cause of secondary osteoporosis, and abnormal thyroid hormone signaling has recently been identified as a novel risk factor for osteoarthritis. Skeletal phenotypes in genetically modified mice have faithfully reproduced genetic disorders in humans, revealing the complex physiological relationship between centrally regulated thyroid status and the peripheral actions of thyroid hormones. Studies in mutant mice also established the paradigm that T3 exerts anabolic actions during growth and catabolic effects on adult bone. Thus, the skeleton represents an ideal physiological system in which to characterize thyroid hormone transport, metabolism, and action during development and adulthood and in response to injury. Future analysis of T3 action in individual skeletal cell lineages will provide new insights into cell-specific molecular mechanisms and may ultimately identify novel therapeutic targets for chronic degenerative diseases such as osteoporosis and osteoarthritis. This review provides a comprehensive analysis of the current state of the art.

THE IMPACT OF AGE IN THE MANAGEMENT OF HYPOTHYROIDISM: RESULTS OF A NATIONWIDE SURVEY

OBJECTIVE

Evidence exists that thyroid-stimulating hormone (TSH) increases with age and lowering the TSH goal in older patients on thyroid hormone may cause over-treatment. Risks of overtreatment include cardiac and skeletal events. We assessed practice patterns regarding TSH goals and explored factors influencing physicians' decision making when managing hypothyroidism.

METHODS

Members of the American College of Physicians, the American Academy of Family Practice, and the Endocrine Society were surveyed to determine goal TSH when treating hypothyroidism.

RESULTS

Fifty-three percent of physicians reported factoring patient age into their decision making when managing hypothyroidism. Patient age was prioritized third (53%), following patient symptoms (69.2%) and cardiac arrhythmias (65.7%). In multivariable analysis, endocrinologists (P = .002), internists (P = .049), physicians in academic settings (P = .003), and high-volume physicians (P = .021) were more likely to consider patient age when determining goal TSH. When presented with scenarios differing in patient gender and age, 90% of physicians targeted a TSH ≤3.0 mIU/L in 30-year-old patients. Fifty-three percent of respondents targeted a TSH ≤3.0 mIU/L in octogenarians, but 90% targeted a TSH >1.5 mIU/L in this group. Regardless of gender, physician-reported TSH goal ranges (0.1 to 0.5, 0.6 to 1.5, 1.6 to 3.0, and 3.1 to 5.0 mIU/L) increased in a direct relationship to patient age (P<.001).

CONCLUSION

Just over half of physicians consider patient age when determining TSH goal. When presented with scenarios differing in patient age and gender, physicians targeted a higher TSH goal in octogenarians. This may indicate an attempt to avoid overtreatment in this group. Consensus is needed among physicians regarding the role of patient age in hypothyroidism management.

ABBREVIATIONS

TSH = thyroid-stimulating hormone.