Prevalence of subclinical thyroid dysfunction and its relation to socioeconomic deprivation in the elderly: a community-based cross-sectional survey

Changes in thyroid function and evolution of subclinical thyroid disease in older men

OBJECTIVE

Prevalence of subclinical thyroid disease increases with age, but optimal detection and surveillance strategies remain unclear particularly for older men. We aimed to assess thyroid stimulating hormone (TSH) and free thyroxine (FT4) concentrations and their longitudinal changes, to determine the prevalence and incidence of subclinical thyroid dysfunction in older men.

DESIGN, PARTICIPANTS AND MEASUREMENTS

Longitudinal study of 994 community-dwelling men aged ≥70 years without known or current thyroid disease, with TSH and FT4 concentrations assessed at baseline and follow-up (after 8.7 ± 0.9 years). Factors associated with incident subclinical thyroid dysfunction were examined by logistic regression and receiver operating characteristic analyses.

RESULTS

At baseline, 85 men (8.6%) had subclinical hypothyroidism and 10 (1.0%) subclinical hyperthyroidism. Among 899 men euthyroid at baseline (mean age 75.0 ± 3.0 years), 713 (79.3%) remained euthyroid, 180 (20.0%) developed subclinical/overt hypothyroidism, and 6 (0.7%) subclinical/overt hyperthyroidism. Change in TSH correlated with baseline TSH (r = .16, p < .05). Change in FT4 correlated inversely with baseline FT4 (r = -0.35, p < .05). Only higher age and baseline TSH predicted progression from euthyroid to subclinical/overt hypothyroidism (fully-adjusted odds ratio [OR] per year=1.09, 95% confidence interval [CI] = 1.02-1.17, p = .006; per 2.7-fold increase in TSH OR = 65.4, CI = 31.9-134, p < .001). Baseline TSH concentration ≥2.34 mIU/L had 76% sensitivity and 77% specificity for predicting development of subclinical/overt hypothyroidism.

CONCLUSIONS

In older men TSH concentration increased over time, while FT4 concentration showed little change. Subclinical or overt hypothyroidism evolved in one fifth of initially euthyroid men, age and higher baseline TSH predicted this outcome. Increased surveillance for thyroid dysfunction may be justified in older men, especially those with high-normal TSH.

Prevalence of thyroid dysfunction and its relationship to income level and employment status: a nationwide population-based study in Spain

PURPOSE

The influence of socioeconomic conditions on the prevalence of thyroid dysfunction in the population has been scarcely studied to date. The aim of this study has been to evaluate the influence of income level and employment status on the prevalence of hypothyroidism and hyperthyroidism.

METHODS

A cross-sectional study was performed using the population-based database BDCAP (Base de Datos Clínicos de Atención Primaria, Primary Care Clinical Database) to analyze the prevalence of thyroid dysfunction in the Spanish population classified by income groups and employment status.

RESULTS

Of the 40,613,229 people registered in the BDCAP in 2020, there were 2,596,041 (6.39%) with a diagnosis of hypothyroidism and 418,722 (1.03%) with hyperthyroidism. The prevalence of hypothyroidism in people with high income (≥ 100,000 euros/year), medium income (18,000-99,999 euros/year), low income (< 18,000 euros/year), and very low income were, respectively, 4.23%, 5.74%, 6.75%, and 7.01% (P < 0.001). The prevalence of hyperthyroidism in the same income groups also showed an increasing trend as income decreased (0.65%, 0.94%, 1.08%, and 1.10%; P < 0.001). Unemployed people had higher frequencies of hypothyroidism (7.35%) and hyperthyroidism (1.22%) than working people (5.80 and 1.00%, respectively) and inactive people (4.21 and 0.52%, respectively; P < 0.001).

CONCLUSION

Socioeconomic conditions are related to the prevalence of thyroid dysfunction. Low-income or unemployed people have a higher frequency of both hypothyroidism and hyperthyroidism.

Prevalence and risk factors of untreated thyroid dysfunctions in the older Caucasian adults: Results of PolSenior 2 survey

Introduction

To determine the prevalence of treated and untreated thyroid dysfunction and to identify factors associated with increased risk of undiagnosed thyroid dysfunction in older adults.

Methods

The population of 5987 community-dwelling Polish Caucasian seniors aged 60 years and above who participated in the PolSenior 2 study (2018–2019). Population-based cross-sectional multidisciplinary study in design. Data from structured questionnaires, geriatric tests, and scales were obtained from all study participants who underwent anthropometric and blood pressure measurements during three home visits. Assessment of thyroid function was based on TSH serum measurements.

Results

The prevalence of thyroid dysfunction in the Polish population aged 60 years or above was estimated at 15.5% (21.5% in women and 7.2% in men), with 3.2% of undiagnosed individuals among them. The prevalence of hypothyroidism and hyperthyroidism in the studied group was 13.9% (19.4% in women and 6.3% in men) and 1.6% (2.1% in women and 0.9% in men) respectively, untreated hypothyroidism was revealed in 21.9% (in 160 out of 732 subjects) and untreated hyperthyroidism in 34.2% of subjects (in 41 out of 120 participants). In multiple regression analysis independent risk factors for thyroid disorders being untreated were older age (> 75 years), male sex, a low education level (primary or lower), and low utilization of medical services.

Conclusions

One-fifth of Polish Caucasian seniors with hypothyroidism and one-third with hyperthyroidism are untreated. Older, poorly educated and rarely utilizing medical services seniors, especially men, are more frequently untreated for thyroid dysfunction and some of them do not benefit from contemporary achievements in medicine.

Association of Elevated Thyroid Stimulating Hormone with Atherosclerotic Cardiovascular Disease and Its Mortality in Elderly Community-Dwelling Chinese

Purpose

With increase of population aging, the prevalence of atherosclerotic cardiovascular disease (ASCVD) and elevated serum thyroid stimulating hormone (TSH) in elderly is increasing. High TSH level was reported to be associated with ASCVD and CVD mortality; however, few are studied in Chinese population, especially in the elderly. This study aimed to investigate the prevalence of elevated serum TSH and ASCVD in an elderly population of Chinese community and to explore the association between high serum TSH and ASCVD or CVD mortality.

Patients and Methods

We conducted a study involving 3814 adults who were at least 60 years of age. Questionnaires, physical examinations, and laboratory blood samples were collected in 2014, and a 78-months follow-up for cardiovascular and all-cause mortality was performed till December of 2020. Logistics regression was used to analyze the association between TSH and ASCVD. We used Cox models to assess the hazard ratios (HRs) for all-cause and CVD mortality across changes in serum TSH.

Results

In this study, the prevalence of the elevated serum TSH was 19.8%, and significantly higher in women than in men (24.5% vs 13.9%, p < 0.001). The prevalence of ASCVD was 21.7%. In logistics regression models, elevated TSH was associated with ASCVD after adjusting for the risk factors of ASCVD in people over the age of 70 years (adjusted OR 1.054, P = 0.014). After a follow-up of 6.5 years, total 441 (11.6%) all-cause death and 174 (4.6%) death of CVD were observed. In Cox regression model, no significant correlation was found between TSH and all-cause mortality or CVD mortality in the elderly population.

Conclusion

In the elderly population, there is high prevalence of elevated serum TSH and ASCVD. Elevated TSH seemed to be not associated with risk of all-cause or CVD mortality.

Economic and Cardiometabolic Risk Factors Are Predictors of Lower Thyroid Stimulating Hormone (TSH) Levels in Hispanic/Latinx Adults with Euthyroidism-A Community-Based Study

Thyroid hormone abnormalities are among the most common endocrine disorders comorbidly suffered alongside metabolic syndrome and type 2 diabetes mellitus (T2DM), and within the euthyroid range they may also impact other outcomes, such as mood disorders. This study aimed to observationally examine the relationship between TSH and social determinants of health and clinical measures in a euthyroid Hispanic/Latinx patient sample with a diagnosis of anxiety and/or depression disorders from a community health clinic. A needs assessment was completed using a random sample of 100 de-identified medical records of individuals who received free medical care, including mental health, at a community-based clinic. Those with low normal TSH (<2 mIU/L) compared with high normal TSH (≥2 mIU/L) had a greater odds of food insecurity (p = 0.016) and being at 100% of the federal poverty level (p = 0.015). The low normal TSH group had significantly higher fasting glucose (p = 0.046), hemoglobin A1c (p = 0.018), and total cholesterol (p = 0.034) compared with the high normal TSH group. In those with T2DM, individuals with low normal TSH had six-times greater odds of having high fasting glucose (p = 0.022) and high hemoglobin A1c (p = 0.029). These relationships warrant further study, to inform future public health policies and follow-up care for underserved and vulnerable communities.

Transient high thyroid stimulating hormone and hypothyroidism incidence during follow up of subclinical hypothyroidism

Objectives. Given the high prevalence of subclinical hypothyroidism (SCH), defined as high thyroid stimulating hormone (TSH) and normal free thyroxine (FT4), and uncertainty on treatment, one of the major challenges in clinical practice is whether to initiate the treatment for SCH or to keep the patients under surveillance. There is no published study that has identified predictors of short-term changes in thyroid status amongst patients with mild elevation of TSH (4.5-10 mIU/L). Subjects and Results. A cohort study was conducted on patients with SCH detected through a general population screening program, who were followed for six months. This project identified factors predicting progression to hypothyroid status, persistent SCH and transient cases. A total of 656 participants joined the study (431 controls and 225 were patients with SCH). A part of participants (12.2%) developed biochemical hypothyroidism during the follow-up, while 73.8% of the subjects became euthyroid and the remained ones (13.4%) stayed in the SCH status. The incidence of overt hypothyroidism for participants with TSH above 6.9 mIU/L was 36.7%, with incidence of 42.3% for females. Anti-thyroid peroxidase antibodies (TPO) positivity is an important predictor of development of hypothyroidism; however, it could be also positive due to transient thyroiditis. Conclusions. It can be concluded that females with TSH above 6.9 mIU/L, particularly those with free triiodothyronine (FT3) and FT4 in the lower half of the reference range, are more likely to develop biochemical hypothyroidism. Therefore, it is recommended to give them a trial of levothyroxine replacement. It is also recommended to repeat TSH after six months for male subjects and participants with baseline TSH equal or less than 6.9 mIU/L.

Reinterpreting patterns of variation in human thyroid function: An evolutionary ecology perspective

Thyroid hormone reference intervals—used to determine normal thyroid function —currently don’t take into account many significant factors that can cause variation in thyroid hormone levels. These factors include age, sex, ethnicity, season, time of day, iodine content in the diet, socioeconomic status, stress levels, body composition, immune status, menstrual cycle phase, and overall health status. This paper shows how early life experiences as well as short term stressors may affect variation in thyroid function. These are energetic challenges to which the thyroid physiology can respond to. Our investigation shows that much variation in thyroid function is natural. It may result from a complex interplay of evolutionary, genetic, developmental, and physiological factors in response to energetic challenges in the environment, beyond what is currently considered in biomedicine. A new research agenda for thyroid health should explore the way that diversity in thyroid function has evolved as a response to different contexts people live in—like focusing on how people’s metabolisms adapt to the energetic requirements of their environments.

Two hundred million people worldwide experience some form of thyroid disorder, with women being especially at risk. However, why human thyroid function varies between populations, individuals, and across the lifespan has attracted little research to date. This limits our ability to evaluate the conditions under which patterns of variation in thyroid function are best understood as ‘normal’ or ‘pathological’. In this review, we aim to spark interest in research aimed at understanding the causes of variation in thyroid phenotypes. We start by assessing the biomedical literature on thyroid imbalance to discuss the validity of existing reference intervals for diagnosis and treatment across individuals and populations. We then propose an evolutionary ecological framework for understanding the phylogenetic, genetic, ecological, developmental, and physiological causes of normal variation in thyroid function. We build on this approach to suggest testable predictions for how environmental challenges interact with individual circumstances to influence the onset of thyroid disorders. We propose that dietary changes, ecological disruptions of co-evolutionary processes during pregnancy and with pathogens, emerging infections, and exacerbated stress responses can contribute to explaining the onset of thyroid diseases. For patients to receive the best personalized care, research into the causes of thyroid variation at multiple levels is needed.

Birth control pills and risk of hypothyroidism: a cross-sectional study of the National Health and Nutrition Examination Survey, 2007-2012

OBJECTIVE

The association between use of birth control pills and thyroid function in women has not ever been well studied, but potential risk has been implicated by small sample-sized studies. We aimed to determine this association using a large epidemiological survey.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey conducted in the USA from 2007 to 2012.

PARTICIPANTS

Female respondents aged 18+ who had data on history of taking birth control pills and thyroid function were included. History of taking birth control pills was based on responses on the reproductive health questionnaire. Participants not on antithyroid medication with thyroid-stimulating hormone (TSH) >5.6 mIU/L and those on thyroid hormone replacement regardless of TSH were categorised as hypothyroid. Participants not on thyroid hormone replacement or antithyroid medication who had TSH between 0.34 mIU/L and 5.6 mIU/L were classified as euthyroid.

PRIMARY AND SECONDARY OUTCOME MEASURES

Association between use of birth control pills and hypothyroidism based on multivariate logistic regression analysis.

RESULTS

A total of 5116 female adults with history of taking birth control pills (n=3034) and without (n=2082) were included. A higher prevalence of hypothyroidism was found in those who have ever taken birth control pills (17.7% vs 14.1%; p=0.003). Multivariate logistic regression adjusted for confounding covariables, including age, race, education, body mass index, smoking status, alcohol use, history of thyroid disease, current thyroid disease, first menstrual age, pregnancy history, menopause status and history of hormone replacement use, demonstrated a significant association between history of taking birth control pills for more than 10 years and hypothyroidism (OR, 3.837; 95% CI 1.402 to 10.500; p=0.009).

CONCLUSIONS

Longer history of using birth control pills was strongly associated with hypothyroidism, especially for more than 10 years.

Influence of educational level on test and treatment for incident hypothyroidism

OBJECTIVE

The incidence of hypothyroidism is not expected to differ by socioeconomic factors. However, the decision to test and initiate treatment may differ. We aimed to examine whether educational level influences the probability of thyroid stimulation hormone (TSH)-measurement and initiation of levothyroxine treatment.

DESIGN

Citizens in the greater Copenhagen Area during 2001-2015 were included. Individual-level data on educational level, diagnoses, GP-contact, TSH-measurement and medication were derived from administrative and healthcare registers. The relative risks (RR) between educational levels of annual TSH-measurement and treatment initiation following a TSH-measurement were analysed in Poisson regression models with generalized estimation equations.

RESULTS

A TSH-measurement was performed in 19% of 9,390,052 person years. The probability of TSH-measurement was higher with short (RR 1.16 [95% CI 1.15-1.16]) and medium (RR 1.11 [95% CI 1.06-1.12]) compared with long education. Treatment was initiated after 0.8% of 2,049,888 TSH-measurements. For TSH < 5 mIU/L, RR for treatment initiation ranged between 0.47 (95%CI 0.39-0.57) and 0.78 (95%CI 0.67-0.91) for short and medium compared with long education. For TSH 5-10 mIU/L, there was no statistically significant difference. For TSH > 10 mIU/L, RR was 1.07 (95% CI 1.02-1.12) for short and 1.08 (95% CI 1.03-1.13) for medium compared with long education.

CONCLUSION

The probability of TSH-measurement was higher with shorter education, and the probability of treatment initiation with TSH > 10 mIU/L was marginally higher with short-medium education compared with long education. However, the probability of treatment initiation with TSH < 5 mIU/L, that is treatment incongruous with guidelines, was substantially higher in persons with long education.

Clinical Parameters Are More Likely to Be Associated with Thyroid Hormone Levels than with Thyrotropin Levels: A Systematic Review and Meta-Analysis

Background: Though the functional states of other endocrine systems are not defined on the basis of levels of controlling hormones, the assessment of thyroid function is based on levels of the controlling hormone thyrotropin (TSH). We, therefore, addressed the question as to whether levels of thyroid hormones [free thyroxine (fT4), total triiodothyronine (TT3)/free triiodothyronine (fT3)], or TSH levels, within and beyond the reference ranges, provide the better guide to the range of clinical parameters associated with thyroid status. Methods: A PubMed/MEDLINE search of studies up to October 2019, examining associations of levels of thyroid hormones and TSH, taken simultaneously in the same individuals, with clinical parameters was performed. We analyzed atrial fibrillation, other cardiac parameters, osteoporosis and fracture, cancer, dementia, frailty, mortality, features of the metabolic syndrome, and pregnancy outcomes. Studies were assessed for quality by using a modified Newcastle-Ottawa score. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. A meta-analysis of the associations was performed to determine the relative likelihood of fT4, TT3/fT3, and TSH levels that are associated with the clinical parameters. Results: We identified 58 suitable articles and a total of 1880 associations. In general, clinical parameters were associated with thyroid hormone levels significantly more often than with TSH levels-the converse was not true for any of the clinical parameters. In the 1880 considered associations, fT4 levels were significantly associated with clinical parameters in 50% of analyses. The respective frequencies for TT3/fT3 and TSH levels were 53% and 23% (p < 0.0001 for both fT4 and TT3/fT3 vs. TSH). The fT4 and TT3/fT3 levels were comparably associated with clinical parameters (p = 0.71). More sophisticated statistical analyses, however, indicated that the associations with TT3/fT3 were not as robust as the associations with fT4. Conclusions: Thyroid hormones levels, and in particular fT4 levels, seem to have stronger associations with clinical parameters than do TSH levels. Associations of clinical parameters with TSH levels can be explained by the strong negative population correlation between thyroid hormones and TSH. Clinical and research components of thyroidology currently based on the measurement of the thyroid state by reference to TSH levels warrant reconsideration.

Thyrotoxicosis in an Indigenous New Zealand Population - a Prospective Observational Study

Background

Reported international incidence rates of thyrotoxicosis vary markedly, ranging from 6 to 93 cases per 100 000 per annum. Along with population demographics, exposures, and study design factors, ethnicity is increasingly being recognized as a potential factor influencing incidence. This study aimed to document the epidemiology and clinical presentation of thyrotoxicosis for Māori, the indigenous population in New Zealand.

Methods

A prospective study of adult patients presenting with a first diagnosis of thyrotoxicosis between January 2013 and October 2014 to a single New Zealand center. Demographic data were collected, and detailed clinical assessment performed.

Results

With 375 patients, an incidence rate of thyrotoxicosis of 73.0 per 100 000 per annum was identified. Of these, 353 (94.1%) participated in the study. The median age of the cohort was 47 years, 81% were female, and 58% had Graves disease. The overall incidence of thyrotoxicosis for Māori, the indigenous people of New Zealand, was higher than non-Māori (123.9 vs 57.3 per 100 000 per annum). Rates of both Graves disease and toxic multinodular goiter were higher in Māori as compared to non-Māori (incidence rate ratios of 1.9 [1.4, 2.6] and 5.3 [3.4, 8.3], respectively), with this increase being maintained after controlling for age, deprivation, and smoking.

Conclusions

Māori, the indigenous people of New Zealand, have an increased incidence of thyrotoxicosis compared to non-Māori and, in particular, toxic multinodular goiter. A greater understanding of the epidemiology of thyrotoxicosis in other indigenous and marginalized ethnic groups may help to optimize therapeutic pathways, equitable care and outcomes.

Subclinical thyroid dysfunction symptoms in older adults: cross-sectional study in UK primary care

BACKGROUND

Subclinical thyroid dysfunction - abnormal serum thyrotrophin (thyroid-stimulating hormone; TSH) concentrations with normal free thyroxine (FT4) is common in older people. It remains unclear whether individuals with subclinical serum status experience an increased symptom profile.

AIM

To compare the prevalence of those symptoms typically associated with overt thyroid dysfunction in older individuals with a subclinical and euthyroid serum profile.

DESIGN AND SETTING

Cross-sectional study, nested within the Birmingham Elderly Thyroid Study (BETS); from 19 UK general practices.

METHOD

Adults living in a community setting (aged ≥65 years), without overt thyroid dysfunction or associated treatment, self-reported the presence or absence of 18 symptoms (while serum result naïve). Serum concentrations of TSH and FT4 were measured to establish thyroid status.

RESULTS

A total of 2870 individuals were screened: 2703 (94%) were categorised as euthyroid (normal), 29 (1%) subclinically hyperthyroid, and 138 (5%) subclinically hypothyroid. Symptoms were common in all groups. No significant differences in the prevalence of individual symptoms were observed between the euthyroid and subclinically hypothyroid groups nor in comparison with the subclinically hyperthyroid group. Multivariate logistic regression analysis failed to reveal an association between individual or multiple symptoms and subclinical status.

CONCLUSION

Findings suggest that subclinical thyroid dysfunction does not confer a symptom burden in older individuals and support adherence to guidelines in the non-treatment of subclinical thyroid dysfunction. GPs may use the findings to reassure older people presenting with symptoms that subclinical thyroid dysfunction is an unlikely explanation. The presence of persistently abnormal TSH concentrations may be linked to long-term risks of cardiovascular disease, especially atrial fibrillation, but whether this should prompt treatment and whether such treatment alters vascular outcomes is unknown.

Levothyroxine for the Treatment of Subclinical Hypothyroidism and Cardiovascular Disease

Subclinical hypothyroidism is a biochemical condition defined by elevated serum thyroid-stimulating hormone levels in the setting of normal levels of the peripheral thyroid hormones, thyroxine and triiodothyronine. Thyroid hormones act on the heart through various mechanisms and subclinical hypothyroidism has been associated with risk factors for cardiovascular disease, such as hypertension and dyslipidemia. In addition, evidence from multiple studies supports an association between subclinical hypothyroidism and cardiovascular disease. However, the use of levothyroxine in subclinical hypothyroidism to reduce cardiovascular disease risk is not clearly beneficial. Treatment with levothyroxine may only provide benefit in certain subgroups, such as patients who are younger or at higher risk of cardiovascular disease. At present, most of the international societal guidelines advise that treatment decisions should be individualized based on patient age, degree of serum thyroid-stimulating hormone (TSH) elevation, symptoms, cardiovascular disease (CVD) risk, and other co-morbidities. Further study in this area is recommended.

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

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

Iodine status and characteristics of Korean adolescents and their parents based on urinary iodine concentration: a nationwide cross-sectional study

PURPOSE

Iodine is a major component of thyroid hormones. Both deficiency and excess of iodine are major risk factors for thyroid disease, making it important to accurately assess iodine level in the human body. Urinary iodine concentration (UIC) is a commonly used measure of iodine status. However, there is little research on iodine status and related characteristics in Korean adolescents.

METHODS

Using data from the sixth Korea National Health and Nutrition Examination Survey (KNHANES VI) for the years 2013-2015, we analyzed UIC and thyroid function test results in adolescents aged 10-18 years and their parents. We also investigated the influence of socioeconomic factors and family history of thyroid disease on iodine status.

RESULTS

Mean UIC in Korean adolescents was 963.5±55.7 μg/L. Among evaluated subjects, 6.6%±1.0%, 29.8%±1.7%, and 63.9%±1.9% had low (UIC&lt;100 μg/L), adequate (UIC: 100-299.9 μg/L), and excess (UIC≥300 μg/L) iodine concentrations, respectively. Based on regional trends, the incidence of iodine deficiency exceeded 10% in several regions, even though there was a dominance of regions with excess iodine. Parental UIC, female sex, average monthly income, and expenditure were all found to affect the iodine status of Korean adolescents.

CONCLUSION

Although regional differences exist, the iodine status in Korean adolescents is mainly affected by the eating habits of their families and socioeconomic factors. Therefore, monitoring of iodine status is necessary in this population.

Hypothyroidism in the older population

BACKGROUND

Both overt hypothyroidism as well as minor elevations of serum thyrotropin (TSH) levels associated with thyroid hormones within their respective reference ranges (termed subclinical hypothyroidism) are relatively common in older individuals. There is growing evidence that treatment of subclinical hypothyroidism may not be beneficial, particularly in an older person. These findings are relevant at a time when treatment with thyroid hormones is increasing and more than 10-15% of people aged over 80 years are prescribed levothyroxine replacement therapy.

MAIN BODY

The prevalence of hypothyroidism increases with age. However, the reference range for TSH also rises with age, as the population distribution of TSH concentration progressively rises with age. Furthermore, there is evidence to suggest that minor TSH elevations are not associated with important outcomes such as impaired quality of life, symptoms, cognition, cardiovascular events and mortality in older individuals. There is also evidence that treatment of mild subclinical hypothyroidism may not benefit quality of life and/or symptoms in older people. It is unknown whether treatment targets should be reset depending on the age of the patient. It is likely that some older patients with non-specific symptoms and incidental mild subclinical hypothyroidism may be treated with thyroid hormones and could potentially be harmed as a result. This article reviews the current literature pertaining to hypothyroidism with a special emphasis on the older individual and assesses the risk/benefit impact of contemporary management on outcomes in this age group.

CONCLUSIONS

Current evidence suggests that threshold for treating mild subclinical hypothyroidism in older people should be high. It is reasonable to aim for a higher TSH target in treated older hypothyroid patients as their thyroid hormone requirements may be lower. In addition, age-appropriate TSH reference ranges should be considered in the diagnostic pathway of identifying individuals at risk of developing hypothyroidism. Appropriately designed and powered randomised controlled trials are required to confirm risk/benefit of treatment of subclinical hypothyroidism in older people. Until the results of such RCTs are available to guide clinical management international guidelines should be followed that advocate a conservative policy in the management of mild subclinical hypothyroidism in older individuals.

Overt and Subclinical Hypothyroidism in the Elderly: When to Treat?

Hypothyroidism is characterized by increased thyrotropin (TSH) levels and reduced free thyroid hormone fractions while, subclinical hypothyroidism (sHT) by elevated serum TSH in the face of normal thyroid hormones. The high frequency of hypothyroidism among the general population in Western Countries made levothyroxine (LT4) one of the 10 most prescribed drugs. However, circulating TSH has been demonstrated to increase with aging, regardless the existence of an actual thyroid disease. Thus, when confronting an increase in circulating TSH levels in the elderly, especially in the oldest old, it is important to carry an appropriate diagnostic path, comprehensive of clinical picture as well as laboratory and imaging techniques. In the current review, we summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly-therapy. The treatment of choice for hypothyroid patients is hormone replacement with LT₄ but, it is important to consider multiple factors before commencing the therapy, from the age dependent TSH increase to the presence of an actual thyroid disease and comorbidities. When treatment is necessary, a tailored therapy should be chosen, considering poly-pharmacy and frailty. A careful follow-up and treatment re-assessment should be always considered to avoid the risk of over-treatment. It is important to stress the need of educating the patient for a correct administration of LT₄, particularly when poly-therapy is in place, and the importance of a tailored therapeutic approach and follow-up, to avoid overtreatment.

An Age-Specific Serum Thyrotropin Reference Range for the Diagnosis of Thyroid Diseases in Older Adults: A Cross-Sectional Survey in China

Background: The fact that serum thyrotropin (TSH) levels increase with age may influence the diagnosis of thyroid diseases in older adults. This study aimed to establish an age-specific serum TSH reference range, examine the prevalence of thyroid diseases in older adults ≥65 years, and analyze the risk factors. Methods: A cross-sectional study of adult populations in 10 cities in China was conducted from 2010 to 2011. A total of 15,008 subjects were randomly selected and completed the present study. Urinary iodine concentration, serum TSH, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) titers were measured. Thyroid ultrasonography and questionnaires were completed by all the subjects. When the TSH level was abnormal, free thyroxine and/or free triiodothyronine levels were measured. Results: When the reference range of the general population was used, the prevalence rates of overt hypothyroidism (Ohypo) and subclinical hypothyroidism (Shypo) in older adults ≥65 years were significantly higher than those in younger adults <65 years (2.09% vs. 0.80% and 19.87% vs. 16.23%, respectively; p < 0.001). Positive TPOAb and positive TgAb were associated with the prevalence of Shypo in older adults. An age-specific serum TSH reference range was formulated according to guidelines set forth by the National Academy of Clinical Biochemistry. Both the median and upper limit values of serum TSH in older adults were higher than those in younger adults (2.58 [0.75-8.86] mIU/L vs. 2.38 [0.76-6.57] mIU/L; p < 0.001). Using the age-specific serum TSH reference range, the prevalence of Shypo in older adults was 3.3%, which was significantly lower than the prevalence based on the reference range of the general population (3.3% vs. 19.87%). The prevalence rates of Ohypo, overt hyperthyroidism (Ohyper), and subclinical hyperthyroidism (Shyper) did not change much (Ohypo: 1.6% vs. 2.09%; Ohyper: 0.7% vs. 0.52%; and Shyper: 3.8% vs. 0.73%). Positive TPOAb, but not positive TgAb, was also associated with the prevalence of Shypo as diagnosed with the age-specific serum TSH reference range. Conclusion: The serum TSH level increases with age, which may represent a normal compensatory phenomenon in older adults ≥65 years. To prevent misdiagnosis and mistreatment, the use of an age-specific serum TSH reference range is recommended in older adults for the diagnosis of thyroid diseases.

Hypothyroidism in the Elderly: Who Should Be Treated and How?

Hypothyroidism is among the most frequent chronic diseases in the elderly, and levothyroxine (l-T4) is worldwide within the 10 drugs more prescribed in the general population. Hypothyroidism is defined by increased serum thyroid-stimulating hormone (TSH) values and reduced circulating free thyroid hormones, whereas subclinical hypothyroidism (sHT) is characterized by free hormone fractions within the normal ranges and has been divided into two classes, depending on circulating TSH levels (above or below 10 mIU/L). Given that during aging, a natural trend toward higher values of circulating TSH has been reported, it is necessary to verify carefully the diagnosis of sHT to tailor an appropriate follow-up and ad hoc therapy, avoiding unnecessary or excessive treatment. In the current review, we evaluate the state of the art on hypothyroidism in the elderly with special focus on the effect of sHT on cognition and the cardiovascular system function. We also summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with an elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly therapy. In conclusion, personalized therapy is crucial in good clinical practice, and in the management of older patients with sHT, multiple factors must be considered, including age-dependent TSH cutoffs, thyroid autoimmunity, the burden of comorbidities, and the possible presence of frailty. l-T4 is the drug of choice for the treatment of hypothyroid older people, but the risk of overtreatment, potential adverse drug reactions, and patient compliance should always be considered and thyroid status periodically reassessed.

Graves' disease: Introduction, epidemiology, endogenous and environmental pathogenic factors

Graves' disease is the most frequent cause of hyperthyroidism. Many questions remain about the choice of diagnostic evaluations and treatment strategy according to clinical context (age, gender, pregnancy, etc.) and about the best management of the main extrathyroidal complication that is Graves orbitopathy. The exact pathogenic mechanisms are not fully clear. They associate genetic factors, interactions between endogenous and environmental factors, and immune system dysregulation. Graves' orbitopathy is one of the consequences of this partial understanding. Iatrogenic Graves' disease induced by the new targeted therapies are described and could help to better understand the molecular pathways involved in the disease and to develop new therapeutic approaches.

Prevalence of thyroid dysfunction in a Large Southern European Population. Analysis of modulatory factors. The APNA study

CONTEXT

To study the prevalence of thyroid dysfunction in a very large unselected population.

OBJECTIVE

To determine the prevalence of abnormal thyroid function and evaluate potential modulatory factors.

DESIGN AND SETTING

The Estudio de Atención Primaria de Navarra, The APNA Study, is a cross-sectional study conducted in northern Spain. It involved 303 883 people, of 20 years of age and older, who live in the Navarra region. Participants are covered by the public healthcare system and medical records are digitalized.

MAIN OUTCOME MEASURES

The information was gathered from e-registered data regarding serum thyrotropin (TSH), thyroid hormones, thyroid antibody concentration and clinical context. Measurements were logged (demographic information and potential thyroid function modulatory factors).

RESULTS

Serum TSH (mU/L) normal range was established at 0.7-4.28. At the time of the study, 87% of the Navarra population had a TSH level within the normal range. Mean serum TSH in euthyroid individuals was higher in women (2.15) than in men (1.96) (P < .001) and higher in the obese with body mass index (BMI) ≥30 kg/m² (2.12) as compared to the non-obese BMI <30 kg/m² (2.06) (P < .001). Mean TSH for the entire population was 1.9. The native Spanish population had statistically significantly lower TSH (1.87) than non-native Spanish (2.15) (P < .001). Additionally, we observed that serum TSH levels decreased with age and an increase in the prevalence of hypothyroidism in the elderly and among people with low-income levels. The prevalence of thyroid dysfunction in Navarra was 12.3%. The prevalence of hypothyroidism (or high TSH) in the population was 8.8% (13.3% in women, 4.2% in men), and the prevalence of hyperthyroidism (or low TSH) was 4.3% (5.6% in women, 3.0% in men).

CONCLUSIONS

Nearly 15% of the general population suffers from biochemical thyroid dysfunction. The serum TSH level appears to be influenced by sex, BMI, age, ethnic origin and socio-economic status.

Stability of thyroid function in older adults: the Birmingham Elderly Thyroid Study

BACKGROUND

Thyroid function tests (TFTs) are among the most requested tests internationally. However, testing practice is inconsistent, and potentially suboptimal and overly costly. The natural history of thyroid function remains poorly understood.

AIM

To establish the stability of thyroid function over time, and identify predictors of development of overt thyroid dysfunction.

DESIGN AND SETTING

Longitudinal follow-up in 19 general practices in the UK.

METHOD

A total of 2936 participants from the Birmingham Elderly Thyroid Study (BETS 1) with a baseline TFT result indicating euthyroid or subclinical state were re-tested after approximately 5 years. Change in thyroid-stimulating hormone (TSH), free thyroxine (FT₄), and thyroid status between baseline and follow-up was determined. Predictors of progression to overt dysfunction were modelled.

RESULTS

Participants contributed 12 919 person-years; 17 cases of overt thyroid dysfunction were identified, 13 having been classified at baseline as euthyroid and four as having subclinical thyroid dysfunction. Individuals with subclinical results at baseline were 10- and 16-fold more likely to develop overt hypothyroidism and hyperthyroidism, respectively, compared with euthyroid individuals. TSH and FT₄ demonstrated significant stability over time, with 61% of participants having a repeat TSH concentration within 0.5 mIU/L of their original result. Predictors of overt hypothyroidism included new treatment with amiodarone (odds ratio [OR] 92.1), a new diagnosis of atrial fibrillation (OR 7.4), or renal disease (OR 4.8).

CONCLUSION

High stability of thyroid function demonstrated over the 5-year interval period should discourage repeat testing, especially when a euthyroid result is in the recent clinical record. Reduced repeat TFTs in older individuals is possible without conferring risk, and could result in significant cost savings.

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.

MANAGEMENT OF ENDOCRINE DISEASE: Subclinical thyrotoxicosis: prevalence, causes and choice of therapy

Subclinical thyrotoxicosis is a condition affecting up to 10% of the population in some studies. We have reviewed literature and identified studies describing prevalences, causes and outcomes of this condition. Treatment should be considered in all subjects if this biochemical abnormality is persistent, especially in case of symptoms of thyrotoxicosis or in the presence of any complication. In particular, treatment should be offered in those subclinically thyrotoxic patients with a sustained serum TSH below 0.1 U/L. However it is important to recognise that there are no large controlled intervention studies in the field and thus there is no high quality evidence to guide treatment recommendations. In particular, there is no evidence for therapy and there is weak evidence of harm from thyrotoxicosis if serum TSH is in the 0.1-0.4 IU/L range. In this review, we describe the different causes of subclinical thyrotoxicosis, and how treatment should be tailored to the specific cause. We advocate radioactive iodine treatment to be the first-line treatment in majority of patients suffering from subclinical thyrotoxicosis due to multinodular toxic goitre and solitary toxic adenoma, but we do generally not recommend it as the first-line treatment in patients suffering from subclinical Graves' hyperthyroidism. Such patients may benefit mostly from antithyroid drug therapy. Subclinical thyrotoxicosis in early pregnancy should in general be observed, not treated. Moreover, we advocate a general restriction of therapy in cases where no specific cause for the presumed thyroid hyperactivity has been proven.

Thyroid hormones in extreme longevity

The aim of the present review was to summarize knowledge about thyroid hormones (THs) and longevity. Longevity is a complex multifactorial phenomenon on which specific biological pathways, including hormonal networks involved in the regulation of homeostasis and survival, exert a strong impact. THs are the key responsible for growth, metabolism rate and energy expenditure, and help in maintaining cognition, bone and cardiovascular health. THs production and metabolism are fine tuned, and may help the organism to cope with a variety of environmental challenges. Experimental evidence suggests that hypothyroid state may favor longevity by reducing metabolism rate, oxidative stress and cell senescence. Data from human studies involving healthy subjects and centenarians seem to confirm this view, but THs changes observed in older patients affected by chronic diseases cannot be always interpreted as a protective adaptive mechanism aimed at reducing catabolism and prolonging survival. Medications, selected chronic diseases and multi-morbidity can interfere with thyroid function, and their impact is still to be elucidated.

Comorbidities, Concomitant Medications, and Diet as Factors Affecting Levothyroxine Therapy: Results of the CONTROL Surveillance Project

Background

The CONTROL Surveillance Project was a comprehensive patient-based survey conducted among hypothyroid patients undergoing treatment. The primary objective of the study was to specifically quantify the prevalence of factors adversely affecting levothyroxine therapy.

Methods

Participants were selected from a large proprietary database. Those eligible for the study completed a 21-question survey.

Results

Of the eligible hypothyroid patients, 925 (92.5 %) were being treated with levothyroxine monotherapy. The mean age was 60.4 years; 755 (81.6 %) were female and 168 (18.2 %) were male. Almost half of those receiving levothyroxine (435, 47.0 %) had at least one comorbid condition that could adversely affect its absorption: gastroesophageal reflux disease (33.8 % of patients), irritable bowel syndrome (9.7 %), lactose intolerance (7.8 %), or a history of gastric bypass surgery or bowel resection (3.0 %). Other factors reported by many patients that could adversely affect levothyroxine absorption included use of prescription medications (20.6 %) and over-the-counter medications (34.3 %) used to treat comorbid gastrointestinal (GI) conditions; use of dietary supplements (51.8 %, primarily calcium and iron); and intake of foods/beverages high in fiber, iodine, or soy (68.0 %). Of the 13.4 % who reported difficulty controlling their hypothyroid symptoms, significantly more patients with comorbid GI conditions reported such difficulty (7.8 versus 5.6 %, P < 0.01). Frequent changes in levothyroxine dosing (two or more dose changes in the past year) were reported by 8.0 % of survey participants. Those with GI comorbidities were nearly twice as likely to have such changes (5.0 versus 3.0 %, P < 0.01).

Conclusion

Better initial workup of patients, including identification of relevant GI comorbidities and allergies, may help in the early detection of factors that may affect the performance of levothyroxine.

International variation in GP treatment strategies for subclinical hypothyroidism in older adults: a case-based survey

BACKGROUND

There is limited evidence about the impact of treatment for subclinical hypothyroidism, especially among older people.

AIM

To investigate the variation in GP treatment strategies for older patients with subclinical hypothyroidism depending on country and patient characteristics.

DESIGN AND SETTING

Case-based survey of GPs in the Netherlands, Germany, England, Ireland, Switzerland, and New Zealand.

METHOD

The treatment strategy of GPs (treatment yes/no, starting-dose thyroxine) was assessed for eight cases presenting a woman with subclinical hypothyroidism. The cases differed in the patient characteristics of age (70 versus 85 years), vitality status (vital versus vulnerable), and thyroid-stimulating hormone (TSH) concentration (6 versus 15 mU/L).

RESULTS

A total of 526 GPs participated (the Netherlands n = 129, Germany n = 61, England n = 22, Ireland n = 21, Switzerland n = 262, New Zealand n = 31; overall response 19%). Across countries, differences in treatment strategy were observed. GPs from the Netherlands (mean treatment percentage 34%), England (40%), and New Zealand (39%) were less inclined to start treatment than GPs in Germany (73%), Ireland (62%), and Switzerland (52%) (P = 0.05). Overall, GPs were less inclined to start treatment in 85-year-old than in 70-year-old females (pooled odds ratio [OR] 0.74 [95% confidence interval [CI] = 0.63 to 0.87]). Females with a TSH of 15 mU/L were more likely to get treated than those with a TSH of 6 mU/L (pooled OR 9.49 [95% CI = 5.81 to 15.5]).

CONCLUSION

GP treatment strategies of older people with subclinical hypothyroidism vary largely by country and patient characteristics. This variation underlines the need for a new generation of international guidelines based on the outcomes of randomised clinical trials set within primary care.

Socioeconomic conditions across life related to multiple measures of the endocrine system in older adults: Longitudinal findings from a British birth cohort study

Background

Little is known about how socioeconomic position (SEP) across life impacts on different axes of the endocrine system which are thought to underlie the ageing process and its adverse consequences. We examined how indicators of SEP across life related to multiple markers of the endocrine system in late midlife, and hypothesized that lower SEP across life would be associated with an adverse hormone profile across multiple axes.

Methods

Data were from a British cohort study of 875 men and 905 women followed since their birth in March 1946 with circulating free testosterone and insulin-like growth factor-I (IGF-I) measured at both 53 and 60–64 years, and evening cortisol at 60–64 years. Indicators of SEP were ascertained prospectively across life—paternal occupational class at 4, highest educational attainment at 26, household occupational class at 53, and household income at 60–64 years. Associations between SEP and hormones were investigated using multiple regression and logistic regression models.

Results

Lower SEP was associated with lower free testosterone among men, higher free testosterone among women, and lower IGF-I and higher evening cortisol in both sexes. For example, the mean standardised difference in IGF-I comparing the lowest with the highest educational attainment at 26 years (slope index of inequality) was −0.4 in men (95% CI -0.7 to −0.2) and −0.4 in women (−0.6 to −0.2). Associations with each hormone differed by SEP indicator used and sex, and were particularly pronounced when using a composite adverse hormone score. For example, the odds of having 1 additional adverse hormone concentration in the lowest compared with highest education level were 3.7 (95% CI: 2.1, 6.3) among men, and 1.6 (1.0, 2.7) among women (P (sex interaction) = 0.02). We found no evidence that SEP was related to apparent age-related declines in free testosterone or IGF-I.

Conclusions

Lower SEP was associated with an adverse hormone profile across multiple endocrine axes. SEP differences in endocrine function may partly underlie inequalities in health and function in later life, and may reflect variations in biological rates of ageing. Further studies are required to assess the likely functional relevance of these associations.

•

Socioeconomic position (SEP) across life was related to multiple hormone measures.

•

Lower SEP was related to lower testosterone in men, higher testosterone in women.

•

Lower SEP was related to lower IGF-I and higher evening cortisol in both sexes.

•

SEP differences in multiple hormone axes may underlie later life health inequality.

Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water

BACKGROUND

While previous research has suggested that there is an association between fluoride ingestion and the incidence of hypothyroidism, few population level studies have been undertaken. In England, approximately 10% of the population live in areas with community fluoridation schemes and hypothyroidism prevalence can be assessed from general practice data. This observational study examines the association between levels of fluoride in water supplies with practice level hypothyroidism prevalence.

METHODS

We used a cross-sectional study design using secondary data to develop binary logistic regression models of predictive factors for hypothyroidism prevalence at practice level using 2012 data on fluoride levels in drinking water, 2012/2013 Quality and Outcomes Framework (QOF) diagnosed hypothyroidism prevalence data, 2013 General Practitioner registered patient numbers and 2012 practice level Index of Multiple Deprivation scores.

FINDINGS

We found that higher levels of fluoride in drinking water provide a useful contribution for predicting prevalence of hypothyroidism. We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area).

INTERPRETATION

In many areas of the world, hypothyroidism is a major health concern and in addition to other factors-such as iodine deficiency-fluoride exposure should be considered as a contributing factor. The findings of the study raise particular concerns about the validity of community fluoridation as a safe public health measure.

Multiple hormonal dysregulation as determinant of low physical performance and mobility in older persons

Mobility-disability is a common condition in older individuals. Many factors, including the age-related hormonal dysregulation, may concur to the development of disability in the elderly. In fact, during the aging process it is observed an imbalance between anabolic hormones that decrease (testosterone, dehydroepiandrosterone sulphate (DHEAS), estradiol, insulin like growth factor-1 (IGF-1) and Vitamin D) and catabolic hormones (cortisol, thyroid hormones) that increase. We start this review focusing on the mechanisms by which anabolic and catabolic hormones may affect physical performance and mobility. To address the role of the hormonal dysregulation to mobility-disability, we start to discuss the contribution of the single hormonal derangement. The studies used in this review were selected according to the period of time of publication, ranging from 2002 to 2013, and the age of the participants (≥65 years). We devoted particular attention to the effects of anabolic hormones (DHEAS, testosterone, estradiol, Vitamin D and IGF-1) on both skeletal muscle mass and strength, as well as other objective indicators of physical performance. We also analyzed the reasons beyond the inconclusive data coming from RCTs using sex hormones, thyroid hormones, and vitamin D (dosage, duration of treatment, baseline hormonal values and reached hormonal levels). We finally hypothesized that the parallel decline of anabolic hormones has a higher impact than a single hormonal derangement on adverse mobility outcomes in older population. Given the multifactorial origin of low mobility, we underlined the need of future synergistic optional treatments (micronutrients and exercise) to improve the effectiveness of hormonal treatment and to safely ameliorate the anabolic hormonal status and mobility in older individuals.

The Role of the Multiple Hormonal Dysregulation in the Onset of "Anemia of Aging": Focus on Testosterone, IGF-1, and Thyroid Hormones

Anemia is a multifactorial condition whose prevalence increases in both sexes after the fifth decade of life. It is a highly represented phenomenon in older adults and in one-third of cases is "unexplained." Ageing process is also characterized by a "multiple hormonal dysregulation" with disruption in gonadal, adrenal, and somatotropic axes. Experimental studies suggest that anabolic hormones such as testosterone, IGF-1, and thyroid hormones are able to increase erythroid mass, erythropoietin synthesis, and iron bioavailability, underlining a potential role of multiple hormonal changes in the anemia of aging. Epidemiological data more consistently support an association between lower testosterone and anemia in adult-older individuals. Low IGF-1 has been especially associated with anemia in the pediatric population and in a wide range of disorders. There is also evidence of an association between thyroid hormones and abnormalities in hematological parameters under overt thyroid and euthyroid conditions, with limited data on subclinical statuses. Although RCTs have shown beneficial effects, stronger for testosterone and the GH-IGF-1 axis and less evident for thyroid hormones, in improving different hematological parameters, there is no clear evidence for the usefulness of hormonal treatment in improving anemia in older subjects. Thus, more clinical and research efforts are needed to investigate the hormonal contribution to anemia in the older individuals.

The second wave of the Controlled Antenatal Thyroid Screening (CATS II) study: the cognitive assessment protocol

BACKGROUND

Children whose mothers had low thyroid hormone levels during pregnancy have been reported to have decreased cognitive function. The reported research is part of the follow-on study of the Controlled Antenatal Thyroid Screening Study (CATS I), a randomised controlled trial which investigated the impact of treated vs. untreated low thyroid hormone level in women during pregnancy with the primary outcome being the child's IQ at age 3. No significant differences in IQ were found between the treated and untreated groups. These children are now aged between 7 and 10 years and aspects of their cognitive functioning including their IQ are being reassessed as part of CATS II.

METHODS/DESIGN

Cognitive assessments generate an IQ score and further tests administered will investigate long term memory function and motor coordination. The aim is to complete the assessments with 40% of the children born to mothers either in the treated or untreated low thyroid hormone groups (n = 120 per group). Also children born to mothers who had normal thyroid functioning during CATS I are being assessed for the first time (n = 240) to provide a comparison. Assessments are conducted either in the research facility or the participant's home.

DISCUSSION

The study is designed to assess the cognitive functioning of children born to mothers with low thyroid hormone levels and normal thyroid functioning during pregnancy. This is the largest study of its type and also is distinguishable in its longitudinal design. The research has the potential to have a significant impact on public health policy in the UK; universal screening of thyroid hormone levels in pregnancy may be the recommendation.

The burden of common chronic disease on health-related quality of life in an elderly community-dwelling population in the UK

BACKGROUND

Given the high prevalence of chronic conditions and multimorbidity in the elderly, there is a need to determine which chronic conditions have the greatest impact on health-related quality of life (HRQL) and identify where additional intervention may be required.

OBJECTIVE

To explore the impact of a range of common chronic conditions on HRQL in a community-based population aged 65 years or more in the UK.

METHODS

Secondary analysis of data derived from a large (n = 5849) cross-sectional study. HRQL was assessed using the EuroQoL EQ-5D. Multivariable models were used to estimate the relative effect of 15 individual common chronic conditions and combinations of these conditions on HRQL.

RESULTS

Mean age of participants was 74.6 years, 49.2% were male. The mean EQ-5D index score was 0.78 (standard deviation 0.2), range -0.43 to 1.00. Overall, 53% (n = 3078) of the cohort reported problems with pain, 39% (n = 2273) with mobility and 9% (n = 529) with self-care. Multivariate modelling demonstrated that impaired HRQL was significantly associated with 13 of the 15 common chronic conditions studied. Clinically meaningful reductions in EQ-5D index scores were observed for osteoarthritis (-0.081, P = 0.0006), neurological disease (-0.172, P < 0.0001) and depression (-0.269, P < 0.001).

CONCLUSIONS

This study quantifies the relative impact of 13 common chronic conditions on HRQL in a UK-based community-dwelling ageing population. Findings indicate that osteoarthritis, depression and neurological disease have a strong clinically important negative effect on HRQL. These findings may help clinical decision making and priority setting for management of individuals with multimorbidity.

Changes in the prevalence of hypothyroidism: the HUNT Study in Norway

OBJECTIVE

Untreated hypothyroidism is common in iodine-replete areas. Frequent thyroid function testing and use of levothyroxine treatment for subclinical hypothyroidism suggest that the prevalence may have decreased. Therefore, in this study, we examined changes in the prevalence of hypothyroidism in a Norwegian county from 1995-1997 to 2006-2008.

DESIGN

Population surveys of 33,917 individuals in 1995-1997 and 49,180 individuals in 2006-2008 were carried out.

METHODS

We compared the prevalence of untreated overt, untreated subclinical, and treated hypothyroidism between 1995-1997 and 2006-2008.

RESULTS

The prevalence of untreated overt hypothyroidism among women decreased by 84% from 1995-1997 (0.75%) to 2006-2008 (0.12%) (prevalence ratio (PR) 0.16; 95% CI 0.10-0.26). The corresponding decrease among men was 43% from 0.21 to 0.12% (PR 0.57; 95% CI 0.28-1.16). The prevalence of untreated subclinical hypothyroidism decreased by 64% from 3.0 to 1.1% in women (PR 0.36; 95% CI 0.31-0.42) and decreased by 54% from 2.1 to 1.0% in men (PR 0.46; 95% CI 0.38-0.56). Conversely, the prevalence of treated hypothyroidism among women increased by 60% from 5.0 to 8.0% (PR 1.60, 95% CI 1.50-1.71), and the corresponding prevalence in men doubled from 1.0 to 2.0% (PR 1.96; 95% CI 1.59-2.41). The prevalence of any form of hypothyroidism remained essentially similar at 9% in women and 3% in men.

CONCLUSIONS

The prevalence of untreated hypothyroidism in this Norwegian county decreased strongly from 1995-1997 to 2006-2008. The findings suggest that the prevalence of untreated hypothyroidism in populations with easy access to thyroid function testing and levothyroxine treatment may now be low.

Progesterone therapy increases free thyroxine levels--data from a randomized placebo-controlled 12-week hot flush trial

OBJECTIVE

Thyroid hormones and progesterone both influence core temperature, metabolism and are crucial during pregnancy. Our objective was to discover whether progesterone therapy caused changes in thyroid physiology compared with placebo.

DESIGN

Post hoc analysis from a randomized (1:1) placebo-controlled 12-week trial of oral micronized progesterone (Progesterone, 300 mg/d at bedtime) for hot flushes (vasomotor symptoms, VMS) conducted in an academic medical centre.

PATIENTS

Postmenopausal euthyroid, healthy (without cardiovascular diseases or risks) women, 1-11 years since last flow on no thyroid or ovarian hormone therapy with VMS participated.

MEASUREMENTS

Primary outcomes were final and 12-week changes in TSH, FreeT3 and FreeT4 on progesterone vs placebo.

RESULTS

Women with thyroid data (69 of 133 in original trial) were randomized to progesterone (n = 39) or placebo (n = 30)-baseline thyroid values were normal. There were no VMS-thyroid interactions-VMS Score (number × intensity) did not correlate with TSH, FreeT3 or FreeT4 (Spearman's rank correlations: -0.03 to -0.19, respectively; all P > 0.15). At 12 weeks on progesterone, TSH levels tended to be lower (1.7 mU) than on placebo (2.2), P = 0.06; FreeT4 levels were higher (16.4 pmol/l) than on placebo (15.3), P = 0.02. FreeT3 was unchanged throughout. Analysis of covariance showed a significant increase in FreeT4 on progesterone (+2.5 pmol/l; 1.9-3.0) vs on placebo (+1.7; 1.1-2.4) with 95% CI of difference = 0.8 pmol/l [0.0, 1.6], P = 0.04.

CONCLUSIONS

Progesterone caused a significant FreeT4 increase that was discovered during this randomized controlled VMS trial. The clinical importance of this increased FreeT4 level remains to be documented. Registered at ClinialTrials.gov#NCT00152438.

Comparison of mortality in hyperthyroidism during periods of treatment with thionamides and after radioiodine

CONTEXT

Hyperthyroidism is common, but opinions regarding optimal therapy with antithyroid drugs or radioiodine (131-I) differ. There are no randomized trials comparing these options in terms of mortality.

OBJECTIVE

The aim of the study was to determine whether mortality associated with hyperthyroidism varies with treatment administered or other factors.

DESIGN, SETTING, AND PATIENTS

We conducted a prospective observational population-based study of 1036 subjects aged ≥ 40 years presenting to a single specialist clinic from 1989-2003 with a first episode of hyperthyroidism who were followed until June 2012.

INTERVENTIONS

Antithyroid drugs or radioiodine (131-I) were administered.

MAIN OUTCOME MEASURES

We compared causes of death with age-, sex-, and period-specific mortality in England and Wales and used within-cohort analysis of influence of treatment modality, outcome, disease etiology, severity and control, and comorbidities.

RESULTS

In 12 868 person-years of follow-up, 334 died vs 290.6 expected (standardized mortality ratio [SMR], 1.15 [95% confidence interval (CI),1.03-1.28]; P = .01). Increased all-cause mortality largely reflected increased circulatory deaths (SMR, 1.20 [95% CI, 1.01-1.43]; P = .04). All-cause mortality was increased for the person-years accumulated during thionamide treatment (SMR, 1.30 [95% CI, 1.05-1.61]; P = .02) and after 131-I not associated with hypothyroidism (SMR, 1.24 [95% CI, 1.04-1.46]; P = .01) but not during T₄ replacement for 131-I-induced hypothyroidism (SMR, 0.98 [95% CI, 0.82-1.18]; P = .85). Within-cohort analysis comparing mortality during thionamide treatment showed a similar hazard ratio (HR) for all-cause mortality when 131-I did not result in hypothyroidism (HR, 0.95 [95% CI, 0.70-1.29]), but reduced mortality with 131-I-induced hypothyroidism (HR, 0.70 [95% CI, 0.51-0.96]). Reduced mortality associated with hypothyroidism was seen only in those without significant comorbidities and not in those with other serious diseases. Atrial fibrillation at presentation (P = .02) and an increment of 10 pmol/L in serial free T₄ concentration during follow-up (P = .009) were independently associated with mortality.

CONCLUSIONS

Among hyperthyroid subjects aged 40 years or older, mortality was increased during periods of thionamide treatment and after radioiodine not resulting in hypothyroidism, but not during follow-up after radioiodine-induced hypothyroidism. Independent associations of mortality with atrial fibrillation and incomplete biochemical control during treatment indicate potential causative links with poor outcome.

Circadian rhythm of TSH levels in subjects with Alzheimer's disease (AD)

OBJECTIVES

The circadian rhythm of serum thyroid stimulating hormone (TSH) levels in patients with Alzheimer's disease was measured by means of a case-control study.

METHODS

Serum samples from cases and controls were collected continuously for 2 days, and then once every 2 h (even number time-point during the first day and odd number time-point in the second). TSH was detected by radioimmunoassay.

RESULTS

AD patients had no significant circadian rhythm in serum TSH levels, whereas normal controls did. In normal controls, serum TSH levels from 19:00 to 20:00 were the lowest (19:00, 3.89 ± 0.97 mIU/L; 20:00, 3.76 ± 0.84 mIU/L) and those in the period 2:00-4:00 were the highest (2:00, 6.15 ± 0.94 mIU/L; 3:00, 6.32 ± 1.04 mIU/L; 4:00, 6.39 ± 1.13 mIU/L; F = 6.762, df = 23, P = 0.002). However, in AD patients, 24-h serum TSH levels were 3.80-4.03 mIU/L (F = 0.897, df = 23, P = 0.996). At the 24 time-points, except for the four time-points from 16:00 to 19:00, TSH levels in AD patients were significantly lower than those in normal controls.

CONCLUSIONS

The circadian rhythm of serum TSH levels in AD patients did not appear, and their serum TSH levels were significantly lower than those in normal controls.

SIGNIFICANCE

The circadian rhythm in serum TSH levels in AD patients differs greatly from that of the general population.

Childhood weight gain and thyroid autoimmunity at age 60-64 years: the 1946 British birth cohort study

BACKGROUND

Complex bidirectional relationships have been described between body weight, thyroid function, and risk of thyroid disorders, including thyroid autoimmunity. We used a life-course approach to examine the potential association of childhood or adult body weight with the risk of thyroid autoimmunity and other thyroid disorders at age 60-64 years in a large population-based birth cohort study.

METHODS

In the UK Medical Research Council 1946 British Birth Cohort study, at age 60-64 years, 1277 women and 1185 men (78% of the target sample) responded to a postal questionnaire, which included questions on thyroid disease and thyroid medication. Circulating antithyroid peroxidase antibodies, free T4, and TSH concentrations were measured in 1057 women and 997 men at a subsequent clinic visit. Birth weight was recorded, and height and weight were measured at ages 2, 4, 6, 7, 11, 15 years and also repeatedly in adulthood.

RESULTS

At age 60-64 years, 10.9% of women (139 of 1277) and 2.3% of men (27 of 1185) reported they were taking T4, and 11.5% of women (122 of 1057) and 3.3% of men (33 of 997) had positive anti-TPO antibodies (>100 IU/mL), consistent with thyroid autoimmunity. Among women, both T4 use and positive anti-TPO antibodies at age 60-64 years were positively associated with childhood body weight, childhood overweight, and adult body mass index. Childhood weight gain between 0 and 14 years of age was positively associated with later T4 use (odds ratio 1.21, 95% confidence interval 1.03-1.42) and positive anti-TPO antibodies (1.21, 1.00-1.47). Women who were overweight or obese at age 14 years (127 of 972) had a higher risk of later positive anti-TPO antibodies (2.05, 1.12-3.76). In men and women without any thyroid disorders, serum free T4 concentrations were inversely associated with concurrent body mass index (P = .002).

CONCLUSIONS

Childhood weight gain and childhood overweight conferred an increased susceptibility to later hypothyroidism and thyroid autoimmunity, particularly in women.

Thyroid dysfunction in the elderly

Thyroid dysfunction is common in the general population, and mild or subclinical forms can be present in more than 10% of individuals aged >80 years. The diagnosis of abnormal thyroid hormone concentrations in people aged >60 years poses a challenge, as the clinical presentation of thyroid dysfunction is usually nonspecific, and ageing is associated with a number of physiological changes that can affect thyroid function test results. Furthermore, the presence of acute or chronic nonthyroidal illnesses and the use of medications that interfere with thyroid function tests are common confounders in the determination of thyroid status in the elderly. Early diagnosis and treatment of overt thyroid dysfunction is crucial in this population in view of the marked effects of abnormal circulating thyroid hormone levels on a number of organ systems, including the heart, the skeleton and the neurological system. The clinical significance of mild thyroid overactivity and underactivity remains uncertain, and the need for treatment of subclinical thyroid dysfunction is much debated. A number of large epidemiological studies have identified associations between mild thyroid dysfunction and short-term as well as long-term adverse outcomes, and a small but increasing number of randomized controlled intervention studies have been reported. Guidelines recommend treatment of thyroid dysfunction on the basis of the degree of abnormal serum TSH concentrations, patient age and associated comorbidities. This Review describes the current evidence on the prevalence, diagnosis, management and long-term consequences of thyroid dysfunction in the elderly.

The thyroid--too much and too little across the ages. The consequences of subclinical thyroid dysfunction

Mild thyroid dysfunction is common, and more prevalent than overt hyper- and hypothyroidism. Subclinical (mild) thyroid dysfunction is a biochemical entity characterized by an abnormality of serum TSH associated with normal serum thyroid hormone concentrations. Subclinical hyperthyroidism is thus defined as low or suppressed serum TSH with normal serum-free T4 and T3, while subclinical hypothyroidism is defined as raised serum TSH with normal circulating T4. These biochemical abnormalities are part of the much wider spectrum of thyroid dysfunction which includes overt hyperthyroidism and overt hypothyroidism, but by no means always indicate underlying thyroid disease. There is much debate about the significance of mild abnormalities of thyroid function in terms of symptoms and potential associations with long-term morbidity and mortality and hence much debate about whether to screen for these abnormalities, and, once identified, whether to treat or monitor, and if so, how? Our knowledge base has increased significantly in recent years, principally because studies of large cohorts have begun to define the epidemiology and associations of mild thyroid dysfunction (including short-term and long-term outcomes) and a small but increasing number of randomized-controlled intervention studies have been reported. There is, however, much to learn about these disorders and, given their prevalence, their impact on health.

Thyroid-stimulating hormone is significantly associated with bone health status in men

BACKGROUND AND AIM

Recent studies revealed a novel association between thyroid-stimulating hormone (TSH) and bone health status in healthy male populations. The present study aimed to validate this association and provide new information on the relationship between TSH levels and calcaneal speed of sound (SOS) in men.

METHODS

This cross-sectional study recruited 681 men with complete data of calcaneal SOS, body anthropometry, serum TSH, free triiodothyronine (FT3) and free thyroxine (FT4) levels.

RESULTS

All subjects had FT3 and FT4 levels within the in-house reference range and 13 subjects had lower than normal TSH levels. The results revealed that the SOS value of subjects was significantly associated with TSH after multiple adjustments (p<0.05). When subjects were divided into quintiles according to their TSH levels, the difference of SOS between men with low-normal TSH and high-normal TSH contributed significantly to the association between TSH and bone health status (p<0.05). The significance of the association persisted with the inclusion and exclusion of subclinical hyperthyroid subjects.

CONCLUSIONS

There was a significant association between TSH levels and bone health status in men as assessed by quantitative ultrasound. This age-independent association between TSH and SOS might explain some of the individual variation of bone health status in men.

Clinical disorders in a post war British cohort reaching retirement: evidence from the First National Birth Cohort study

BACKGROUND

The medical needs of older people are growing because the proportion of the older population is increasing and disease boundaries are widening. This study describes the distribution and clustering of 15 common clinical disorders requiring medical treatment or supervision in a representative British cohort approaching retirement, and how health tracked across adulthood.

METHODS AND FINDINGS

The data come from a cohort of 2661 men and women, 84% of the target sample, followed since birth in England, Scotland and Wales in 1946, and assessed at 60-64 years for: cardio and cerebro-vascular disease, hypertension, raised cholesterol, renal impairment, diabetes, obesity, hypothyroidism, hyperthyroidism, anaemia, respiratory disease, liver disease, psychiatric problems, cancers, atrial fibrillation on ECG and osteoporosis. We calculated the proportions disorder-free, with one or more disorders, and the level of undiagnosed disorders; and how these disorders cluster into latent classes and relate to health assessed at 36 years. Participants had, on average, two disorders (range 0-9); only 15% were disorder-free. The commonest disorders were hypertension (54.3%, 95% CI 51.8%-56.7%), obesity (31.1%, 28.8%-33.5%), raised cholesterol (25.6%, 23.1-28.26%), and diabetes or impaired fasting glucose (25.0%, 22.6-27.5%). A cluster of one in five individuals had a high probability of cardio-metabolic disorders and were twice as likely than others to have been in the poorest health at 36 years. The main limitations are that the native born sample is entirely white, and a combination of clinical assessments and self reports were used.

CONCLUSIONS

Most British people reaching retirement already have clinical disorders requiring medical supervision. Widening disease definitions and the move from a disease-based to a risk-based medical model will increase pressure on health services. The promotion of healthy ageing should start earlier in life and consider the individual's ability to adapt to and self manage changes in health.

Why are GPs treating subclinical hypothyroidism? Case note review and GP survey

BACKGROUND

Subclinical hypothyroidism (SCHo) is a common biochemical diagnosis in older age. Evidence of impact is inconclusive and guidelines are inconsistent. With increasing numbers of thyroid function tests (TFTs) performed, GPs frequently have to make management decisions regarding this diagnosis. However, little is known about how SCHo is currently being managed in primary care.

AIM

To explore management of SCHo in primary care and GP reported rationale for treatment of SCHo in older individuals.

DESIGN

Descriptive study using retrospective case note review and GP survey.

SETTING

Nineteen General Practices, Central England, UK.

METHODS

Follow-up of a large cohort with subsequent detailed review of individuals for whom therapy had been initiated following diagnosis of SCHo. Data on practice policies, and rationale behind treatment were collected via GP questionnaire.

RESULTS

Forty-two individuals were treated following identification of SCHo. Factors regarded as supporting instigation of therapy recorded by practitioners included symptoms, a positive antithyroid antibody test and history of radioiodine therapy. In all, 55% were registered at 3/19 practices suggesting significant between practice variation. Reasons for testing included chronic disease check-up (n = 14), presenting 'thyroid symptoms' (n = 5) and presenting other symptoms (n = 9). Reasons for therapy initiation were only recorded in 26 cases and included presence of symptoms, persistently high or increasing serum thyroid stimulating hormone concentration and patient request. Only 2/15 GPs reported having practice guidelines on management.

CONCLUSION

Results suggest that GPs are uncertain how to interpret symptoms and TFT results in older individuals. There is considerable variation in management of SCHo between GPs with some GPs treating patients outside of all guideline recommendations.

Serum thyrotrophin at baseline predicts the natural course of subclinical hyperthyroidism

OBJECTIVE

Optimal therapeutic strategies for subclinical hyperthyroidism are undecided. Overt disease develops in a minority of cases, but the risk factors for progression remain unclear. We examined whether a baseline thyrotrophin (TSH) predicted progression to overt hyperthyroidism in asymptomatic individuals with subclinical hyperthyroidism.

DESIGN, PATIENTS AND MEASUREMENTS

This was a retrospective study of 323 patients with subclinical hyperthyroidism seen in our institution from 2003 to 2010 (mean age 71 years, males 26·9%, females 73·1%, mean follow-up duration 32 months, range 6-93 months). Serum TSH and free thyroxine (FT4) were documented at baseline and during follow-up. After excluding individuals with nonthyroid causes of low TSH, patients were grouped according to initial TSH as: TSH 0·10-0·39 mU/l (grade I) and TSH < 0·10 mU/l (grade II).

RESULTS

Only 38 patients (11·8%) developed overt hyperthyroidism with annual progression rates of 0·6-3·7%. Most patients reverted to normal thyroid status (31·6%) or remained subclinically hyperthyroid (56·7%). Progression to frank hyperthyroidism was higher in grade II than in grade I patients (20·3% vs 6·8%, P < 0·001, Chi square test). Kaplan-Meier curves showed faster progression rates in grade II than grade I (P < 0·001, log rank test). In stepwise multivariate Cox regression analysis, TSH < 0·1 mU/l was associated with overt hyperthyroidism (hazard ratio 3·4, confidence interval 1·6-7·0), whereas age, gender, FT4 and aetiological diagnosis were not associated with hyperthyroidism.

CONCLUSIONS

Thyrotrophin predicts overt hyperthyroidism in asymptomatic individuals with subclinical hyperthyroidism. Patients with TSH < 0·10 mU/l have a higher risk of progressing to hyperthyroidism than those with TSH 0·10-0·39 mU/l.

The incidence of thyroid function abnormalities and natural course of subclinical thyroid disorders, Tehran, I.R. Iran

BACKGROUND

Despite the high prevalence of thyroid dysfunction, the epidemiology and natural course of these disorders have not been identified yet.

AIM

The present survey was conducted to determine the incidence of thyroid dysfunction and natural course of subclinical thyroid disorders in an urban community of Tehran, I.R. Iran.

SUBJECTS AND METHODS

Serum TSH and thyroperoxidase antibody (TPOAb) were measured at baseline and after 6.7 yr from a sample of 1999 randomly selected subjects aged≥20 yr, participants of the Tehran Lipid and Glucose Study (TLGS). Median TSH value and 2.5, 5, 95, and 97.5 TSH percentiles were determined at baseline using data obtained from 808 negative TPOAb subjects with no history of any thyroid disease or surgery, goiter, nodule, taking thyroid hormone preparations or anti-thyroid drugs. In those with abnormal TSH level, total T4 and T3 uptake were measured and free T4 index was calculated.

RESULTS

Normal TSH reference range was 0.4-5.8 μU/ml according to the 2.5 and 97.5 TSH percentiles. The incidence rates of thyroid function abnormalities in 1000 subjects per year were as follows: clinical hypothyroidism: 0.28 in women and 0.21 in men; subclinical hypothyroidism: 11.59 in women and 4.69 in men; clinical hyperthyroidism: 1.4 in women and 0.21 in men; and subclinical hyperthyroidism: 5.72 in women and 3.62 in men. A significant increase was found in the frequency of positive TPOAb in women from 15.9 to 17.7% (p=0.006). Of 8 women with subclinical hypothyroidism at baseline, 5 remained unchanged, 1 became normal, and 1 developed clinical hypothyroidism at followup. Two women with subclinical hyperthyroidism normalized at follow-up. Of 2 men with subclinical hypothyroidism at baseline, 1 remained unchanged, whereas the other progressed to clinical hypothyroidism.

CONCLUSION

After a 6.7 yr follow-up significant increase in the incidence of subclinical thyroid disorders was observed in both men and women, as compared to overt thyroid dysfunction. Increase in the prevalence of TPOAb positivity was observed only in women.

Health history after intrahepatic cholestasis of pregnancy

OBJECTIVE

To establish whether intrahepatic cholestasis of pregnancy (ICP) is associated with other diseases during a woman's lifetime.

DESIGN

Prospective controlled cohort study.

SETTING

University Hospital in Finland.

POPULATION

A total of 575 women with ICP and 1374 control women, all having delivered in 1969-1988. Questionnaires were sent to 544 ICP patients and 1235 control women. Responses were received from 1178 (66.4%).

METHODS

Questionnaire survey in autumn 2010.

MAIN OUTCOME MEASURES

Perceived health, symptoms and complaints, diseases diagnosed by a doctor and use of medicines.

RESULTS

No statistically significant differences were detected in perceived health. Differences in recent symptoms and complaints were small. Diagnoses made by a doctor showed higher frequencies in the ICP group than in control women for other hepatobiliary diseases, breast cancer and hypothyreosis. Diagnosed hypertension and high cholesterol requiring medication as well as cardiac arrhythmia were less frequent in the ICP group. Women in this group used antacid medicines more often than control women.

CONCLUSIONS

There were few differences between the ICP patients and control women except for a higher frequency of later hepatobiliary disease, breast cancer and hypothyreosis. Women with a history of ICP should be screened for hypothyreosis more readily than those without. The higher frequency of breast cancer warrants further research.