Screening for hypothyroidism in elderly inpatients

Disease-modifying antirheumatic drugs and risk of thyroxine-treated autoimmune thyroid disease in patients with rheumatoid arthritis

BACKGROUND

Autoimmune thyroid disease (AITD) and rheumatoid arthritis (RA) share a genetic background, and the prevalence of AITD in RA patients is increased. Whereas immunomodulatory treatments are used in RA, they are rarely used in AITD.

OBJECTIVES

We hypothesized that disease-modifying antirheumatic drugs (DMARDs) as used in RA might lower the risk of incident AITD.

METHODS

A nationwide cohort study including 13,731 patients with new-onset RA from the Swedish Rheumatology Quality Register 2006-2018 and 63,201 matched general population comparators linked to national registers to identify AITD. We estimated relative risks (hazard ratios) of AITD after RA diagnosis in RA patients compared to the general population, and in relation to DMARD treatment, using Cox regression.

RESULTS

Following RA diagnosis, 321 (2.3%) of the RA patients and 1838 (2.9%) of the population comparators developed AITD, corresponding to an incidence of 3.7 versus 4.6 per 1000 person-years, hazard ratio, 0.81; 95% CI, 0.72-0.91. The decreased risk of incident AITD among RA patients compared to the general population was most pronounced among biologic DMARD (bDMARD) treated patients, with a hazard ratio of 0.54; 95% CI, 0.39-0.76. Among RA patients, subgrouped by bDMARD use, TNF-inhibitors were associated with the most pronounced decrease, hazard ratio, 0.67; 95% CI, 0.47-0.96.

CONCLUSIONS

In contrast to the increased prevalence of AITD in RA patients at diagnosis, our results indicate that the risk of AITD decreases following RA diagnosis. This decrease is especially pronounced in RA patients treated with bDMARDs. These findings support the hypothesis that DMARDs might have a preventive effect on AITD.

Does autoimmune thyroid disease affect rheumatoid arthritis disease activity or response to methotrexate?

OBJECTIVE

To investigate if autoimmune thyroid disease (AITD) impacts rheumatoid arthritis (RA) disease activity or response to methotrexate.

METHODS

A nationwide register-based cohort study of 9 004 patients with new-onset RA from the Swedish Rheumatology Quality Register year 2006-2016, with linkage to other nationwide registers to identify comorbidity with AITD defined as thyroxine prescription before RA diagnosis, excluding non-autoimmune causes. We compared RA disease activity using 28-joint Disease Activity Score (DAS28) and its components, and EULAR response, between patients with and without AITD, using logistic regression.

RESULTS

At diagnosis, patient reported outcome measures (PROMs; patient global, Health Assessment Questionnaire Disability Index and pain) but not objective disease activity measures (erythrocyte sedimentation rate and swollen joint count) were significantly higher (p<0.05 for all PROMs) among RA patients with AITD compared with those without. The level of DAS28 was 5.2 vs 5.1. By contrast, AITD had little influence on EULAR response to methotrexate at 3 months (OR of non/moderate response=0.95, 95% CI 0.8 to 1.1), nor at 6 months. When stratified by age, however, AITD was more common among EULAR non/moderate responders at 3 and 6 months in patients below 45 years resulting in ORs of non/moderate response of 1.44 (0.76-2.76) and 2.75 (1.04-7.28).

CONCLUSION

At diagnosis, RA patients with concomitant AITD score worse on patient reported but not on objective RA disease activity measures, while DAS28 was only marginally elevated. The overall chance of achieving a EULAR good response at 3 or 6 months remains unaffected, although among a limited subgroup of younger patients, AITD may be a predictor for an inferior primary response.

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.

Risk of Thyroxine-Treated Autoimmune Thyroid Disease Associated With Disease Onset in Patients With Rheumatoid Arthritis

IMPORTANCE

Autoimmune thyroid disease ([AITD] including hypothyroidism and hyperthyroidism) is the most common organ-specific autoimmune disorder and is more prevalent among patients with rheumatoid arthritis (RA). Real-world studies on when and how this increased risk of AITD develops, in association with the time before or after the onset of RA, are lacking.

OBJECTIVE

To estimate the risk of thyroxine-treated AITD among patients with RA at different time points before and after the diagnosis of RA.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide register-based case-control and cohort study was conducted between January 1, 2006, and June 30, 2013, with a maximum follow-up time of 7 years before and 8 years after diagnosis of RA. The study used the Swedish Rheumatology Quality Register and linkage to other nationwide registers to identify 8090 adults with new-onset RA and a random population-based sample of 80 782 referents matched by age, sex, and residential area. Statistical analysis was performed from July 1, 2015, to June 30, 2017.

EXPOSURES

Presence of AITD in the participants in the case-control design and RA in the participants in the cohort design.

MAIN OUTCOMES AND MEASURES

Prevalence and relative risk of incident AITD before (odds ratios) and after (hazard ratios) diagnosis of RA compared with the population as reference.

RESULTS

There were 8090 patients with RA (5529 women and 2561 men; mean [SD] age, 58.3 [15.2] years) and 80 782 population-based participants as reference who were identified. By the time of diagnosis of RA, the prevalence of AITD was 10.3% among the patients with RA (n = 832) vs 7.1% among the controls (5725 of 80 350) (odds ratio, 1.5; 95% CI, 1.4-1.7). This increased risk of AITD developed during the 5 years (range, 2-5 years) before diagnosis of RA (odds ratio, 1.5; 95% CI, 1.2-1.8) and peaked by the time of diagnosis of RA (range, 0-3 months before diagnosis of RA) (odds ratio, 5.3; 95% CI, 3.7-7.6). From diagnosis of RA and onward, the risk of developing AITD decreased (range, 2-5 years after diagnosis of RA) (hazard ratio, 0.7; 95% CI, 0.5-1.0).

CONCLUSIONS AND RELEVANCE

Compared with the general population, Swedish patients with RA appear to have a higher prevalence of thyroxine-treated AITD at diagnosis of RA and an increased incidence of AITD during the 5-year period before diagnosis of RA. After diagnosis of RA, the risk of developing AITD is suggested to decrease below the expected rate. Besides temporal changes in diagnostic intensity, this pattern of risk raises the question whether AITD may influence the pathogenesis of RA (or vice versa) and, conversely, the question whether antirheumatic therapies may prevent AITD.

Unravelling thyroid dysfunction in rheumatoid arthritis: History matters

AIM

Autoimmune thyroid disease (AITD) frequently coexists with other systemic autoimmune conditions such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Due to the overlapping and nonspecific nature of symptoms, it is difficult to clinically uncover thyroidal illnesses in RA patients. This study was conducted to estimate the prevalence of thyroid dysfunction including the presence of anti-thyroid peroxidase (antiTPO) autoantibodies in patients with RA and to analyze symptomatology of thyroid dysfunction in patients diagnosed with RA.

METHODOLOGY

This cross-sectional, prospective study was conducted on 100 patients with RA, attending the Rheumatology Outpatient Department at St John's Medical College and Hospital, Bangalore, India.

RESULTS

Twenty-two patients had biochemical evidence of thyroid dysfunction, hypothyroidism being the commonest (15/22 patients). Although fatigue and hair loss were the most common symptoms, only weight gain and cold intolerance were found to be statistically significant (P < 0.05) predictors of hypothyroidism and 32 patients were antiTPO positive. It was observed that equal numbers of patients developed hypothyroidism after diagnosis of RA and vice versa.

CONCLUSION

History taking at the bedside to elicit symptoms, especially weight gain and cold intolerance, is quintessential to ensure timely diagnosis of hypothyroidism.

Hypothyroid Symptoms Fail to Predict Thyroid Insufficiency in Old People: A Population-Based Case-Control Study

BACKGROUND

Clinic-based studies have indicated that older hypothyroid patients may present only few symptoms.

METHODS

In this population-based study of hypothyroidism, we investigated how the power of symptom presence predicts overt hypothyroidism in both young and older subjects. We identified patients newly diagnosed with overt autoimmune hypothyroidism in a population (n = 140, median thyroid-stimulating hormone, 54.5; 95% confidence interval [CI], 28.3-94.8; median total T4, 37; 95% CI, 18-52) and individually matched each patient with 4 controls free of thyroid disease (n = 560). Participants filled out questionnaires concerning the presence and duration of symptoms. We compared the usefulness of hypothyroidism-associated symptoms in predicting overt hypothyroidism in different age groups (young: <50 years, middle age: 50-59 years, old: ≥60 years) also taking various confounders into account.

RESULTS

In young hypothyroid patients, all 13 hypothyroidism-associated symptoms studied were more prevalent than in their matched controls, whereas only 3 of those (tiredness, shortness of breath, and wheezing) were more prevalent in old patients. The mean numbers of symptoms presented at disease onset were 6.2, 5.0, and 3.6 at the ages of 0 to 49 years, 50 to 59 years, and 60+ years, respectively. In young versus old people with 0 to 1 symptoms, the odds ratio for being hypothyroid was 0.04 (95% CI, 0.007-0.18) versus 0.34 (95% CI, 0.15-0.78) (reference all other groups). In young versus old subjects reporting ≥4 symptoms, the odds ratio for being hypothyroid was 16.4 (95% CI, 6.96-40.0) versus 2.22 (95% CI, 1.001-4.90). Receiver operating characteristic analyses revealed that the symptom score was an excellent tool for predicting hypothyroidism in young men (area under the receiver operating characteristic curve, 0.91; 95% CI, 0.82-0.998), whereas it was poor in evaluating older women (area under the receiver operating characteristic curve, 0.64; 95% CI, 0.54-0.75).

CONCLUSION

Hypothyroid symptom score is a good discriminating tool to identify hypothyroidism in young patients but fails to identify hypothyroidism in the elderly. Thus, thyroid function should be tested on wide indications in old age.

Thyroxin substitution and the risk of developing rheumatoid arthritis; results from the Swedish population-based EIRA study

OBJECTIVES

Hypothyroidism in iodine-repleted areas is usually of autoimmune nature and leads to chronic thyroxin substitution. It shares some risk factors with anti-citrullinated peptide antibodies (ACPA)-positive rheumatoid arthritis (RA). We asked whether thyroxin substitution associated with risk of ACPA-positive or ACPA-negative RA, and whether interactions with established risk factors were present.

METHODS

Data from a population-based case-control study with incident RA cases were analysed (1998 adult cases, 2252 controls). Individuals reporting thyroxin substitution were compared with those without thyroxin, by calculating OR with 95% CI, excluding participants reporting non-autoimmune causes for thyroxin substitution (thyroid cancer, iodine-containing drugs). Interaction was evaluated by attributable proportion (AP) with 95% CI.

RESULTS

Thyroxin substitution was associated with a twofold risk of both ACPA-positive (OR=1.9, 95% CI 1.4 to 2.6) and ACPA-negative RA (OR=2.1, 95% CI 1.5 to 3.1). For ACPA-positive RA, the risk associated with the combination thyroxin+ HLA-DRB1 shared epitope alleles (SE) was much higher (OR=11.8, 95% CI 6.9 to 20.0) than for thyroxin (OR=1.4, 95% CI 0.7 to 3.0) or SE (OR=5.7, 95% CI 4.6 to 6.9) alone, indicating a strong interaction (AP=0.5, 95% CI 0.2 to 0.8). Thyroxin substitution interacted non-significantly with smoking (AP=0.4, 95% CI 0.0 to 0.7; OR thyroxin+smoking=3.6, thyroxin only=1.5, smoking only=1.8). Thyroxin did not interact with the PTPN22*R620W allele.

CONCLUSIONS

Thyroxin users had a doubled risk of both ACPA-positive and ACPA-negative RA. The risk of ACPA-positive RA was manifold if they smoked or carried the SE. Furthermore, although joint symptoms can be a manifestation of hypothyroidism, physicians might consider whether it could be an early manifestation of RA.

Prevalence of thyroid disorders among older people: results from the São Paulo Ageing & Health Study

This study aimed to estimate prevalence of thyroid disorders in the São Paulo Ageing & Health Study, an epidemiological study addressing several health-adverse outcomes among elderly people living in a poor area of São Paulo, Brazil. All participants answered a questionnaire and had a blood sample collected to assess levels of tireotropic hormone and free-thyroxine. Among 1,373 people (60.8% women), prevalence rates (95% confidence interval) for thyroid dysfunction (%) were: overt hyperthyroidism, 0.7% (0.2-1.1)[women: 0.8% (0.2-1.5); men: 0.4% (0.01-0.9)]; overt hypothyroidism, 5.7% (4.5-6.9) [women: 5.9% (4.3-7.5); men: 5.4% (3.5-7.3)]; subclinical hyperthyroidism, 2.4% (1.6-3.2) [women: 2.8% (1.6-3.9); men: 1.9% (0.7-3.0)]; and subclinical hypothyroidism, 6.5% (5.2-7.8) [women: 6.7% (5.0-8.4); men: 6.1% (4.1-8.2)]. There was no difference in prevalence rates according to gender, but almost 40% of women were diagnosed and under treatment compared to 9% of men. The burden of thyroid disorders in this sample is high and most participants were not aware of them.

Screening of an elderly female population for hypo- and hyperthyroidism by use of a thyroid hormone panel

The elderly female population living in a rural primary health care district in the south of Sweden was screened for hypo- and hyperthyroidism. A total of 1 442 (97.3%) of the 1 482 women 60 years of age or older attended the study. By use of a computer-evaluated thyroid hormone panel, 178 women (12.3%) were identified as probably abnormal. Among them, 8 women (0.55% of total) with previously unknown thyroid disease were detected as overtly hypothyroid. If also 13 women with spontaneous subclinical hypothyroidism were included, the prevalence of earlier unknown hypothyroidism was 21/1 442 (1.5%). The number of subjects with hyperthyroidism discovered by screening was 28/1 442 (1.9%). Although much remains to be elucidated regarding medical, social and economic factors, the high figures obtained for newly discovered abnormal thyroid function suggest that screening for hyper- and hypothyroidism may be worthwhile in such an elderly female population.

Can thyroid dysfunction explicate severe menopausal symptoms?

Many of the menopausal manifestations look like those accredited to thyroid hyperfunction or hypofunction. Can thyroid dysfunction explicate severe menopausal symptoms? The study comprised 350 women with different menopausal symptoms. All women had serum TSH, T3 and free T4 estimated. Women with thyroid dysfunction were appropriately treated and other women were treated with ERT. The study showed that 21 women (6%) had hypothyroidism and 18 (5.1%) had hyperthyroidism. Marked improvement in the menopausal-like symptoms occurred after treatment of the thyroid dysfunction. Elderly women with severe or resistant menopausal symptoms can be offered TSH, T3 and T4 assays to rule out the thyroid disturbances before attempting hormone replacement therapy.

Subclinical hypothyroidism and the risk of coronary heart disease: a meta-analysis

PURPOSE

Subclinical hypothyroidism has been associated with elevated cholesterol and increased risk for atherosclerosis, but data on the risk of coronary heart disease (CHD) are conflicting. We performed a systematic review to determine whether subclinical hypothyroidism is associated with CHD in adults.

METHODS

We searched MEDLINE from 1966 to April 2005, and the bibliographies of key articles to identify studies that provided risk estimates for CHD or cardiovascular mortality associated with subclinical hypothyroidism. Two authors independently reviewed each potential study for eligibility, assessed methodologic quality, and extracted the data.

RESULTS

We identified 14 observational studies that met eligibility criteria. Subclinical hypothyroidism increased the risk of CHD (summary odds ratio [OR]: 1.65, 95% confidence interval [CI], 1.28-2.12). The summary OR for CHD was 1.81 (CI, 1.38-2.39) in 9 studies adjusted or matched for demographic characteristics, and 2.38 (CI, 1.53-3.69) after pooling the studies that adjusted for most cardiovascular risk factors. Sensitivity analyses including only population-based studies and those with formal outcome adjudication procedures yielded similar results. Subgroup analyses by type of study design showed a similar trend, but lower risk, in the 5 prospective cohort studies (OR 1.42, CI, 0.91-2.21), compared with the case-control and cross-sectional studies (OR 1.72, CI, 1.25-2.38).

CONCLUSION

Our systematic review indicates that subclinical hypothyroidism is associated with an increased risk of CHD. Clinical trials are needed to assess whether thyroxine replacement reduces the risk of CHD in subjects with subclinical hypothyroidism.

Low yield of thyroid-stimulating hormone testing in elderly patients with depression

Although hypothyroidism is purportedly an important cause of depression, prior studies have involved small samples of young people and produced conflicting results. We examined the yield of thyroid-stimulating hormone (TSH) testing in a large group of elderly patients with major depression or dysthymic disorder. The study sample comprised 883 outpatients aged 60 years or older from 18 primary care sites enrolled in the intervention arm of a clinical trial of depression management. Thyroid function was assessed by a single TSH value. Depressive diagnoses were confirmed with the Structured Clinical Interview for DSM-IV (SCID) and depression severity was assessed with the HSCL-20, a modified depression scale of the Hopkins Symptom Checklist. TSH results were available for 725 (82.1%) participants. Although 32 (4.4%) of those tested had TSH>5 mIU/L, the vast majority (27/32) had marginally elevated results (5.1-9.4 mIU/L). Only five patients (0.7%) had TSH levels >10 mIU/L. Patients with elevated TSH did not differ from those with TSH < or = 5 mIU/L in the severity or symptom pattern of depression as measured by the baseline HSCL-20 score (P=.37) or SCID score (P=.44). These findings should caution physicians against acceptance of borderline TSH values as the primary cause of a patient's clinical depression.

Hypothyroidism and Parkinson's disease and the issue of diagnostic confusion

Development of hypothyroidism may easily be overlooked when occurring together with Parkinson's disease (PD), because many of the symptoms of the two disorders are similar. We report on a case of a woman suffering from both PD and hypothyroidism and review the literature on the subject.

Crohn’s disease and risk of fracture: does thyroid disease play a role?

AIM: To assess the role of thyroid disease as a risk for fractures in Crohn’s patients.

METHODS: A cross-sectional study was conducted from 1998 to 2000. The study group consisted of 210 patients with Crohn’s disease. A group of 206 patients without inflammatory bowel disease served as controls. Primary outcome was thyroid disorder. Secondary outcomes included use of steroids, immunosuppressive medications, surgery and incidence of fracture.

RESULTS: The prevalence of hyperthyroidism was similar in both groups. However, the prevalence of hypothyroidism was lower in Crohn’s patients (3.8% vs 8.2%, P = 0.05). Within the Crohn’s group, the use of immunosuppressive agents (0% vs 11%), steroid usage (12.5% vs 37%), small bowel surgery (12.5% vs 28%) and large bowel surgery (12.5% vs 27%) were lower in the hypothyroid subset as compared to the euthyroid subset. Seven (3.4%) Crohn’s patients suffered fracture, all of whom were euthyroid.

CONCLUSION: Thyroid disorder was not found to be associated with Crohn’s disease and was not found to increase the risk for fractures. Therefore, screening for thyroid disease is not a necessary component in the management of Crohn’s disease.

Estudo da Função Tiroideana em Uma População com Mais de 50 Anos

Com objetivo de analisar a freqüência de disfunção tiroideana e de identificar possíveis alterações hormonais decorrentes do envelhecimento, estudamos 198 indivíduos com idade variando de 50 a 85 anos e 106 filhos com idade entre 11 e 49 anos. A prevalência de disfunção tiroideana foi semelhante em ambos grupos (12,6% no grupo de estudo e 14,1% entre os filhos). A presença de um ou dois anticorpos antitiroideanos positivos foi também semelhante entre os grupos (9,1% e 12,3% para os idosos e filhos respectivamente), embora sem correlação disfunção tiroideana. nos idosos. Os níveis séricos de T3 e FT4 foram significantemente menores entre os indivíduos mais velhos quando comparados com os filhos (1,27±0,27 x 1,39±0,31 ng/ml e 0,97±0,29 x 1,18±0,76 ng/dl, respectivamente). Não houve diferença entre os grupos quanto aos níveis de TSH, T4 total e TBG. Concluímos que a prevalência de disfunção tiroideana não foi diferente entre os grupos e que a presença de anticorpos antitiroideanos esteve associada com disfunção da tiróide apenas nos indivíduos mais jovens. A correlação inversa dos níveis de T3 e FT4 com a idade pode refletir uma adaptação à menor necessidade dos hormônios com o envelhecimento.

[Is cognitive change related to hypothyroidism reversible with replacement therapy?]

PURPOSE

Although cognitive impairment related to hypothyroidism has been investigated, issues regarding treatment have been less extensively studied. The aim of this study was to assess cognitive function in patients with hypothyroidism just before treatment and after hypothyroidism had resolved.

METHODS

Standardized psychometric assessment (including ten tests) was done in 30 outpatients with biochemical evidence of hypothyroidism (TSH = 92.1 mU/L, range: 11.4-400) and in 30 control subjects matched for age and gender with normal thyroid function. These tests were repeated twice before treatment and after hypothyroidism had been cured. Statistical analysis was done using the Mann-Whitney U test.

RESULTS

The baseline characteristic of patients with hypothyroidism showed that attention, motor speed, memory and visual-spatial organization were significantly impaired. Cognitive decline was significantly greater with increasing age. Cognitive impairment significantly decreased after hypothyroidism had been cured, reaching values obtained in age-matched control subjects.

CONCLUSION

Attention, motor speed, memory and visual-spatial organization are significantly impaired in hypothyroidism, particularly in the elderly, suggesting that ageing could have potential effects on cognitive functions. Hormone-replacement therapy leads to normalization of the cognitive functions.

Evaluation of the elderly patient with weakness: an evidence based approach

Because of the altered physiology of the elderly population, either as a result of aging or as a result of other disease processes, many illnesses may present with features that are either atypical or nonspecific in nature. Difficult and nonspecific complaints such as weakness in an elderly patient must be handled in a judicious, cost-effective, comprehensive, and expeditious manner that benefits both the patient and the emergency department. This article addresses the evaluation of the elderly patient who presents to the ED complaining of weakness.

An investigation of neural networks in thyroid function diagnosis

We investigate the potential of artificial neural networks in diagnosing thyroid diseases. The robustness of neural networks with regard to sampling variations is examined using a cross-validation method. We illustrate the link between neural networks and traditional Bayesian classifiers. Neural networks can provide good estimates of posterior probabilities and hence can have better classification performance than traditional statistical methods such as logistic regression. The neural network models are further shown to be robust to sampling variations. It is demonstrated that for medical diagnosis problems where the data are often highly unbalanced, neural networks can be a promising classification method for practical use.

Do traditional symptoms of hypothyroidism correlate with biochemical disease?

OBJECTIVE

Hypothyroidism often remains undetected because of the difficulty associating symptoms with disease. To determine the relation between symptoms and biochemical disease, we assessed symptoms and serum thyroid function tests, concurrently, for patients with and without hypothyroidism.

DESIGN

Cross-sectional study.

SETTING/PATIENTS

Seventy-six newly diagnosed case patients with overt hypothyroidism and 147 matched control patients identified through outpatient laboratories in Michigan and Colorado.

MEASUREMENTS AND MAIN RESULTS

Patient symptoms were assessed by questionnaire. Case patients reported a higher proportion of hypothyroid symptoms than did control patients (30.2% vs 16.5%, p < .0001). Univariate analysis identified three significant predictors of an elevated level of thyroid-stimulating hormone (TSH) (p < .05), and 13 symptoms which, when they had changed in the past year, were reported more often by case patients with hypothyroidism than by control patients (p < .005). Individuals reporting changes in 7 or more symptoms were significantly more likely to have hypothyroidism (likelihood ratio [LR] = 8.7, 95% confidence interval [CI] 3.8, 20.2); those reporting changes in 2 or fewer symptoms were less likely to have hypothyroidism (LR = 0.5, 95% CI 0.4, 0.7).

CONCLUSIONS

In this sample, the number of hypothyroid symptoms reported was directly related to the level of TSH. The association was stronger when more symptoms were reported. Symptoms that had changed in the past year were more powerful than symptoms reported present at the time of testing. This suggests that traditional symptoms are valuable when deciding which patients to test for hypothyroidism.

Normal thyroxine and elevated thyrotropin concentrations: evolving hypothyroidism or persistent euthyroidism with reset thyrostat

BACKGROUND

The natural course in subjects manifesting normal serum thyroxine (T4), and triiodothyronine (T3), with an elevated thyrotropin (TSH) level demonstrated two distinct outcomes, one progressing to well defined hypothyroidism as expressed by onset of subnormal T4, T3 and a further rise in TSH and the other remaining in the same state. However, thyroid hormone concentrations at the time of diagnosis fail to distinguish between the two groups. Therefore, we examined the influence of alteration in circulating TSH levels on thyroid gland function at the time of diagnosis in subjects with this syndrome to assess the role of pituitary thyroid axis in these different outcomes.

METHODS

24 hour 131I thyroidal uptake was determined in 14 men and 3 women manifesting normal T4, T3 and elevated TSH prior to and again after 1) subcutaneous administration of bovine TSH, 10 units daily for 3 days and 2) daily oral administration of L-triiodothyronine 75 micrograms for 7 days in a randomized sequence at interval of 4 weeks. Subjects were then followed for up to 16 years to assess the natural course.

RESULTS

Basal 24 hour 131I uptake values were within the normal range (10-35%) in all subjects and increased on TSH administration and declined following LT3 administration. However, in eight subjects, these responses were markedly lower (< 20%) when compared with the minimum change (50%) noted in normal volunteers. These subjects progressed to manifest hypothyroidism requiring LT4 therapy within two years as reflected by a progressive decrease to subnormal T4 levels with a further rise in serum TSH. The remaining nine subjects, demonstrated normal responses (> 50%) and only one of these became hypothyroid during the follow-up period of 16 years.

CONCLUSION

All subjects with normal T4 and T3 with elevated TSH do not manifest "subclinical or evolving hypothyroidism". Two distinct populations seem to exist, one with inhibited pituitary thyroid axis progressing to hypothyroidism or true "subclinical hypothyroidism" at the time of diagnosis and the other with normal pituitary thyroid axis, a state of euthyroidism with "reset thyrostat" at a higher TSH concentration, a state probably persisting for their remaining life span.

Clinical epidemiology of endocrine disorders in the elderly

Many epidemiologic studies have examined age-related processes in humans. Some of the difficulties with these studies are noted. Endocrinologic changes of aging often are compensated for by feedback mechanisms and do not cause dysfunction. Common aging changes are reviewed.

Does treatment with L-thyroxine influence health status in middle-aged and older adults with subclinical hypothyroidism?

OBJECTIVE

To determine if health-related quality of life (HRQL) in patients of middle age and older with elevated thyroid-stimulating hormone (TSH) and normal total thyroid hormone levels-subclinical hypothyroidism-improves with L-thyroxine replacement therapy.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Outpatient clinic.

PATIENTS

Thirty-seven patients with subclinical hypothyroidism, most with symptoms consistent with hypothyroidism, over 55 years of age.

INTERVENTIONS

Placebo or L-thyroxine replacement therapy to achieve normal TSH level.

MEASUREMENTS AND MAIN RESULTS

Disease-specific and general HRQL, cognitive function, bone mineral density, lipid levels. The mean daily dose of L-thyroxine replacement in the active group was 68 +/- 21 micrograms. TSH decreased by 8.6 mIU/L (95% confidence interval [CI] 4.1 to 13.1) and T4 increased by 27.9 nmol/L (95% CI 14.8 to 41.2). There was a statistically significant improvement in a composite psychometric memory score in treated versus control patients; all other outcomes showed similar findings in the two groups. Although confidence intervals for most measures did not exclude an important improvement in HRQL with thyroid replacement, no measure of symptoms or HRQL either showed clinically important trends in favor of treatment, or approached conventional levels of statistical significance.

CONCLUSIONS

In middle-aged and older patients with elevated TSH and normal T4, it may not be harmful to follow biochemical and clinical status even in the presence of nonspecific symptoms potentially associated with hypothyroidism.

Association between dementia and elevated TSH: a community-based study

We report on 194 individuals (96 men and 98 women), aged 65 and over, who had dementia assessments and basal TSH measurements as part of an ongoing epidemiological study of dementing disorders in a larger population. Dementia was diagnosed according to DSM-III-R and measured by the Clinical Dementia Rating scale; CDR scores of 0, 0.5, and > or = 1, represent individuals with no dementia (n = 122), possible dementia (n = 29), and definite dementia (n = 43), respectively. The odds ratio for the association of elevated TSH with definite dementia (CDR > or = 1) was 3.8 (95% confidence interval = 1.6, 9.1) and with possible and/or definite dementia (CDR > or = 0.5) was 3.8 (95% confidence interval = 1.6, 9.2), after adjusting for the effects of age, gender, and level of education. This is the first community-based study to report an association between TSH elevation and dementia. Our findings are consistent with recent evidence that subclinical hypothyroidism is associated with cognitive impairment, and that thyroidal state may influence cerebral metabolism.

Does age play a role in clinical presentation of hypothyroidism?

OBJECTIVE

To determine if aging modifies the clinical presentation of hypothyroidism.

DESIGN

Comparison of 24 clinical signs of hypothyroidism between elderly patients (> or = 70 years of age) and younger patients (< or = 55 years of age).

SETTING

Prospective study of patients with chemically confirmed overt hypothyroidism.

PATIENTS

Sixty seven elderly patients (79.3 +/- 6.7 years) and 54 younger patients (40.8 +/- 9 years) were included in the study.

RESULTS

Neither mean duration of evolution nor mean thyroid-stimulating hormone (TSH) level were different between the 2 groups. Two signs were found in more than 50% of the elderly patients (fatigue and weakness). Four signs were significantly less frequent in elderly patients (chilliness, paresthesiae, weight gain, and cramps). Mean number of clinical signs in the elderly (6.6 +/- 4) was significantly smaller than in young patients (9.3 +/- 4.7) (P < 0.01).

CONCLUSIONS

Our results suggest that the presentation of hypothyroidism is altered in the elderly in comparison with young patients in that there are (1) fewer signs or symptoms and (2) diminished frequency of some classical signs. Our results underline the importance of TSH measurement in the elderly.

Parkinson's disease camouflaging early signs of hypothyroidism

Development of hypothyroidism in a patient with Parkinson's disease may be overlooked because the clinical manifestations of the two disorders are similar. In addition, drugs used to treat Parkinson's disease may mask the slight rise in thyrotropin level that is characteristic of the early stages of hypothyroidism. In this article, the authors discuss a case in which the diagnosis of hypothyroidism was delayed in a patient who had previously been diagnosed with signs and symptoms of Parkinson's disease.

The relationship between sleep apnea syndrome and hypothyroidism

To evaluate the prevalence of obstructive sleep apnea syndrome (OSAS) in patients with hypothyroidism, the prevalence of hypothyroidism in patients with OSAS, the possible factors predisposing to sleep-related breathing disorder in hypothyroid patients, and the effect of thyroid hormone in treating hypothyroidism associated with OSAS, we studied 65 patients with proven OSAS (apnea index [AI] > 5) and 20 hypothyroid patients. All patients were monitored for one overnight sleep study using polysomnography (Grass 78). We found only two (3.1 percent) of 65 OSAS patients had thyroid hypofunction. Of 20 patients with hypothyroidism, two showed moderate to severe OSAS and three had mild OSAS. Patients with both hypothyroidism and OSAS had impaired respiratory drive, but this was corrected by thyroid hormone therapy. Patients with hypothyroidism without OSAS were younger and had a lower percentage of ideal body weight than those with both hypothyroidism and OSAS. All hypothyroid patients were snorers. Thyroid hormone replacement was effective in correcting snoring only after one year of therapy. We conclude the following: (1) an overnight sleep study is not necessary in every case of hypothyroidism; (2) thyroid function studies need not be done routinely for every OSAS patient; (3) thyroid hormone therapy is effective for OSAS but it takes longer to correct the snore than respiratory drive; and (4) age and body weight are related to the development of OSAS.

Common thyroid disorders in the elderly

Thyroid disease in the elderly is common but often has an insidious onset with symptoms that mimic those of normal aging. Understanding the significance of thyroid function test results requires an appreciation of the normal physiologic variations of aging and the complicating effects of diseases and medications; only then can one accurately discriminate between various disease processes, order additional appropriate tests, and deliver rational management. The increasing prevalence of thyroid disorders with age, coupled with the current and future dramatic growth of the elderly population, demands that primary care providers be vigilant to the likelihood of thyroid disease and informed as to its most proper, expedient, and cost-effective diagnosis and management.

Prevalence of thyroid dysfunction in elderly subjects from the general population in an iodine deficiency area

The prevalence of thyroid disorders was investigated in 466 (403 female, 63 male) subjects over the age of 60 years (79.2 +/- 7.5 years; mean +/- SD) from the general population in an area of iodine deficiency. In addition to thyroid hormone assays, thyroid antibodies and urinary iodine excretion were determined. In cases with thyroid dysfunction, ultrasound investigations were performed. Twenty-two of the 466 subjects (4.7%) showed hyper- or hypothyroidism; 7 subjects were hyperthyroid (1.5%), 5 had primary hypothyroidism (1.1%), and 10 showed "subclinical" hypothyroidism (2.2%). The latter constellation is defined as an elevation of thyrotropin (TSH) with normal values for thyroxine and triiodothyronine. Most subjects with hyperthyroidism had a goiter by palpation (6/7); thyroid volume by ultrasound (median) was 26.2 mL with an inhomogeneous echo pattern in 6 of the 7 subjects. In 4 cases, a rise in urinary iodine excretion was documented; none had TSH-receptor antibodies. Most subjects with overt or subclinical hypothyroidism had a homogeneous or low-echogenic pattern by ultrasound; thyroid volume (median) was 12.9 mL and 12.7 mL, respectively. By palpation, 8 of the 15 subjects had no goiter. In general, these persons had no rise in urinary iodine excretion (11/13), but most showed an elevation of antibodies against the microsomal antigen and/or thyroglobulin (11/15).(ABSTRACT TRUNCATED AT 250 WORDS)

Thyroid disease in middle-aged and elderly Swedish women: thyroid-related hormones, thyroid dysfunction and goitre in relation to age and smoking

The prevalence of thyroid disease and the concentration of thyroid hormones and thyrotropin were studied in a random population sample of 1154 women, aged 50-72 years, with special reference to the effect of age and smoking. The prevalence of spontaneous hypothyroidism was 3.3% (previously unknown overt and mild disease 1.3%) and the prevalence of hyperthyroidism was 2.5% (previously unknown disease 0.2%). Clinically suspected hyper- or hypothyroidism (very weak to strong) was recorded in 288 women, but was only verified in three cases. The prevalence of visible and palpable thyroid enlargement was 2.1% and 13-14%, respectively. Total thyroxine concentrations increased and free tri-iodothyronine levels decreased significantly with age (P less than 0.001). The serum thyrotropin concentrations were lower in smoking women than in non-smokers in the 50- and 58-year age groups (P less than 0.05). There was no increase in the prevalence of thyroid disease or goitre in the women who were smokers at the time of the study.

Thyroid hormone use: trends in the United States from 1960 through 1988

Thyroid hormone preparations comprised over 1% of all prescriptions filled by retail pharmacies during 1988 in the conterminous United States, i.e., the 48 contiguous states. Their large market share gives the patterns of their use substantial public health importance. This article describes prescription thyroid hormone use in the United States from 1960 through 1988, using pharmaceutical marketing research data collected from panels of retail pharmacies and office-based physicians. Although the use of natural products has declined by over 50% since 1960, about one fourth of all thyroid hormone prescriptions were for natural preparations as recently as 1988. Per capita thyroid mentions (i.e., patient-physician contacts during which a thyroid agent of any kind was recommended, prescribed, dispensed, administered, ordered to be given by a hospital, or given as a sample) doubled during this period among those over 59 years old. Per capita mentions for synthetic thyroid products increased fourfold and tenfold among men and women in this age group, respectively. Use for weight loss, despite the label's boxed warning indicating it to be ineffective and potentially dangerous, has diminished but persists. Obesity was second only to hypothyroidism among the diagnoses underlying thyroid product mentions.

Vitamin B12 deficiency. Important new concepts in recognition

Vitamin B12 deficiency develops over a slowly progressive continuum. Early manifestations may be generalized weakness or fatigue, indigestion, diarrhea, or depression. Pernicious anemia is considered the classic cause, but others include malabsorption because of achlorhydria or other gastric dysfunction, fish tapeworm infection, and strict vegetarianism. Iron deficiency often coexists. Because presentation is often atypical, vitamin B12 deficiency is a diagnostic consideration whenever neuropsychiatric signs or symptoms are unexplained.

Hypothyroidism in the elderly

This review describes the changes in thyroid physiology with aging and notes that normal thyroid status is maintained with advanced age. The increased frequency of hypothyroidism in the elderly is stressed with consideration given to the multiple possible etiologies. The natural history of hypothyroidism is considered as evidenced by the various hormonal abnormalities in subjects with autoimmune thyroiditis and patients previously treated with radioiodine. The potential significance of subclinical hypothyroidism is discussed in regard to nonspecific symptoms and subtle cardiovascular manifestations. The problems in the clinical and laboratory diagnosis of hypothyroidism are reviewed with emphasis on the high index of suspicion and cautious interpretation of plasma thyroxine and thyroid-stimulating hormone (TSH) levels required. Finally the potential problems in treating hypothyroidism in the elderly are discussed in regard to dosage requirements and the need to avoid subclinical hypothyroidism by using the ultrasensitive TSH assay.

Value of screening thyroid function in acute medical admissions to hospital

During a 4-month period an audit was performed to assess the value of thyroid function test (TFT) screening of all medical admissions, without known thyroid disease, to a single hospital. Abnormal TFTs were found in 125 of the 630 patients admitted (20%). Carbimazole or thyroxine was started in 13 patients (2.1%) discovered to have thyrotoxicosis (n = 4) or hypothyroidism (n = 9). In only four of these patients was the diagnosis of thyroid disease apparent clinically. The sick euthyroid state was found in 73 patients (11.6%), while the TSH compensated hypothyroid state was detected in 39 patients (6.2%). The low detection rate of new thyroid disease would suggest that unselective screening of all admissions is unjustified. However, the problem of diagnosing thyroid disease and the morbidity of untreated thyroid disease suggests that biochemical screening of TFTs in a selective group of medical patients admitted to hospital may be justified.

A sensitive thyroid stimulating hormone assay for screening of thyroid functional disorder in elderly Japanese

The use of a screening test for thyroid functional disorder by sensitive thyroid stimulating hormone assay in the elderly was investigated. The basal thyroid stimulating hormone levels predicted the response of thyroid stimulating hormone to thyrotropin releasing hormone; it was suppressed in 99 (99.0%) of 100 hyperthyroid patients. Therefore, not only primary hypothyroidism but also hyperthyroidism can be excluded when the serum thyroid stimulating hormone levels are normal. An epidemiological study was then performed on 2,421 (76.7%) of the Japanese general population aged 40 or over recruited from the residents in Hisayama town and also in 122 residents between 20 and 40 years of age. Additional free T4 measurement was necessary in about 10% of the residents with abnormal TSH levels to confirm the diagnosis of hyperthyroidism or distinguish latent from overt hypothyroidism. There was a significant correlation between age and serum thyroid stimulating hormone levels after logarithmic conversion (r = 0.1533, P less than .001). The prevalence of thyroid dysfunction found in 1,026 males and in 1,395 females aged 40 or over was, respectively: hyperthyroidism, less than 0.1% and 0.2%, latent (subclinical) hypothyroidism, 3.2% and 5.5%, and overt hypothyroidism, 0.4% and 0.7%. We conclude that the screening with this sensitive thyroid stimulating hormone assay and additional free T4 measurement is useful for detection of patients with thyroid functional disorder.

Sensitive thyrotropin assays: analytic and clinical performance criteria

Thyrotropin (TSH) measurements in serum traditionally have been used for the diagnosis and management of hypothyroidism; the availability of highly sensitive TSH assays has expanded the utility of these measurements to include detection of hyperthyroidism, monitoring of thyroxine replacement therapy, and front-line assessment of thyroid function. The analytic advancement that has expanded TSH utility is the noncompetitive "sandwich" immunoassay, which is faster and more sensitive than traditional radioimmunoassays. All such assays, however, are not equivalent; therefore, we have developed analytic and clinical performance criteria for evaluating sensitive TSH assays. These criteria are as follows: (1) the overlap between the assay detection limit and the lower limit of normal should be less than 1%, (2) basal TSH measurements should predict the TSH response to thyrotropin releasing hormone stimulation at least 95% of the time, and (3) basal TSH measurements should be 95% sensitive and 95% specific for detecting hyperthyroidism. Three allegedly sensitive TSH assays were evaluated: (1) the Hybritech two-step Tandem-R method (assay A), (2) the semiautomated Boots-Celltech Sucrosep method (assay B), and (3) a modified Ciba Corning Magic Lite method (assay C). Both assay B and assay C fulfilled out criteria for a sensitive assay; assay B had slightly better performance, and assay C was easier to perform.

The epidemiology of hypothyroidism--an update

Comparison of studies of the prevalence and incidence of hypothyroidism is hampered by differing definitions and population samples. Using a uniform set of diagnostic criteria, the prevalence of previously undiagnosed, spontaneous, overt hypothyroidism in community-based studies has been estimated between 2-4/1000 total population world-wide. If all cases of previously diagnosed hypothyroidism, previous thyroid surgery and radioiodine treatment are included, this prevalence rises to approximately 10/1000, and if subclinical cases are included, then the prevalence is probably over 50/1000 total population. The annual incidence of overt hypothyroidism is between 1-2/1000 for female and around 2/10,000 for males, with individuals having previously elevated TSH and positive circulating thyroid autoantibodies, being particularly at risk. The question of widespread population screening for hypothyroidism is unsettled, but it is probably not cost-effective unless incorporated as part of a screening programme for other conditions such as cervical cancer, or targeted at high risk groups such as post-menopausal women. The combination of serum TSH estimation and a high clinical index of suspicion should detect most patients with thyroid dysfunction, although detailed studies on the use of the more sensitive assays in the detection of both hyper- and hypothyroidism have yet to be published.

Thyroid screening in elderly hospital patients

A screening programme of thyroid disease in 214 elderly patients attending hospital was undertaken incorporating clinical and biochemical assessment. The prevalence of untreated hypothyroidism was 2.8%, treated hypothyroidism 2.8%, untreated hyperthyroidism 0.9%, sub-clinical hypothyroidism 4.7%, and non-thyroidal illness 3.3%. One patient with hypopituitarism was identified. Clinical judgement alone was poor. The costs of such a screening programme are discussed and the benefits highlighted.

Thyroid disease in the elderly. Special features, changes in management

Many changes in thyroid physiology occur with aging. These changes correlate with major alterations in the normal physiologic functioning of the thyroid and with changes in thyroid hormone levels as measured by radioimmunoassay. Clinical manifestations of thyroid disease in elderly patients may be somewhat different than in younger patients. Both hyperthyroidism and hypothyroidism can be more difficult to diagnose in elderly patients because of subtle changes in disease presentation. The incidence of certain thyroid diseases, from benign single nodules to malignant anaplastic carcinoma, increases with age. A deliberate and cautious approach is needed when treating thyroid disease in the elderly, who are inherently more fragile than younger patients.