Outcomes of Thyroid Dysfunction in People Aged Eighty Years and Older: An Individual Patient Data Meta-Analysis of Four Prospective Studies (Towards Understanding Longitudinal International Older People Studies Consortium)

Background: Subclinical and overt thyroid dysfunction is easily detectable, often modifiable, and, in younger age groups, has been associated with clinically relevant outcomes. Robust associations in very old persons, however, are currently lacking. This study aimed to investigate the associations between (sub-)clinical thyroid dysfunction and disability in daily living, cognitive function, depressive symptoms, physical function, and mortality in people aged 80 years and older. Methods: Four prospective cohorts participating in the Towards Understanding Longitudinal International older People Studies (TULIPS) consortium were included. We performed a two-step individual participant data meta-analysis on source data from community-dwelling participants aged 80 years and older from the Netherlands, New Zealand, United Kingdom, and Japan. Outcome measures included disability in daily living (disability in activities of daily living [ADL] questionnaires), cognitive function (Mini-Mental State Examination [MMSE]), depressive symptoms (Geriatric Depression Scale [GDS]), physical function (grip strength) at baseline and after 5 years of follow-up, and all-cause five-year mortality. Results: Of the total 2116 participants at baseline (mean age 87 years, range 80-109 years), 105 participants (5.0%) were overtly hypothyroid, 136 (6.4%) subclinically hypothyroid, 1811 (85.6%) euthyroid, 60 (2.8%) subclinically hyperthyroid, and 4 (0.2%) overtly hyperthyroid. Participants with thyroid dysfunction at baseline had nonsignificantly different ADL scores compared with euthyroid participants at baseline and had similar MMSE scores, GDS scores, and grip strength. There was no difference in the change of any of these functional measures in participants with thyroid dysfunction during five years of follow-up. Compared with the euthyroid participants, no 5-year survival differences were identified in participants with overt hypothyroidism (hazard ratio [HR] 1.0, 95% confidence interval [CI 0.6-1.6]), subclinical hypothyroidism (HR 0.9 [CI 0.7-1.2]), subclinical hyperthyroidism (HR 1.1 [CI 0.8-1.7]), and overt hyperthyroidism (HR 1.5 [CI 0.4-5.9]). Results did not differ after excluding participants using thyroid-influencing medication. Conclusions: In community-dwelling people aged 80 years and older, (sub-)clinical thyroid dysfunction was not associated with functional outcomes or mortality and may therefore be of limited clinical significance.

The impact of subclinical hypothyroidism on long-term outcomes in older patients undergoing percutaneous coronary intervention

BACKGROUND

Subclinical hypothyroidism (SCH) is reportedly associated with an increased risk of adverse events in patients undergoing percutaneous coronary intervention (PCI). The prognostic significance of SCH in the elderly was poorly defined. The purpose of this study was to evaluate the association between SCH and long-term outcomes in older patients undergoing PCI.

METHODS

Three thousand one hundred sixty-eight patients aged 65 years or older who underwent PCI from January 2012 to October 2014 were included. Patients were divided into SCH group (n = 320) and euthyroidism (ET) group (n = 2848) based on thyroid function test. Cox proportional hazard regression analyses were used to estimate the relative risks (RRs) of all-cause death and cardiac death for patients with SCH during a 4-year follow-up period.

RESULTS

There were 227 deaths during the follow-up period including 124 deaths caused by cardiac events. There was no significant difference in mortality rate between the SCH group and the ET group (p > 0.05). After adjustment for covariates, compared with patients with ET, the RRs of death from all-cause and cardiac in patients with SCH were 1.261 (95%CI: 0.802-1.982, p = 0.315) and 1.231 (95%CI: 0.650-2.334, p = 0.524), respectively. When SCH was stratified by age, gender, and degree of thyroid-stimulating hormone elevation, no significant associations were also found in any stratum.

CONCLUSION

Our investigation revealed that SCH was negatively associated with the outcome of PCI in older patients.

Recent evidence sets therapeutic targets for levothyroxine-treated patients with primary hypothyroidism based on risk of death

Since the introduction of sensitive assays for serum thyroid-stimulating hormone (TSH) clinicians have advised hypothyroid patients to adjust the dose of levothyroxine (L-T4) in order to achieve a normal serum TSH. A minority of patients are dissatisfied with this treatment strategy and experience symptoms. Some indirect evidence suggests that a normal serum TSH may not necessarily reflect euthyroidism at the tissue level in patients treated with L-T4. Increasingly hypothyroid patients demand higher doses of L-T4 or liothyronine (L-T3) or animal thyroid extract, often purchased online, and titrate the dose against symptoms, although ample evidence suggests that combination treatment (L-T4 with L-T3) is no more effective than L-T4 alone. Community surveys show that up to 53% of treated hypothyroid patients at any time have a serum TSH outside the normal range. The recommendation by guidelines that the upper limit of the normal range for serum TSH should not be exceeded is supported by robust evidence and is generally accepted by clinicians and patients. However, until recently the lower limit of serum TSH for optimal L-T4 replacement has been controversial. New evidence obtained by two independent large population studies over the past two years has shown that mortality of hypothyroid patients treated with levothyroxine is increased when the serum TSH exceeds or is reduced outside the normal reference range. It is estimated that the implementation of a policy of normalising serum TSH in hypothyroid patients will reduce the risk of death of 28.3 million people in the USA and Europe alone.

Risk of All-Cause Mortality in Levothyroxine-Treated Hypothyroid Patients: A Nationwide Korean Cohort Study

BACKGROUND

Although hypothyroidism is associated with various comorbidities, its relationship with increased all-cause mortality remains controversial. The aim of this nationwide retrospective cohort study was to investigate whether hypothyroid patients treated with levothyroxine had increased mortality compared to controls.

METHODS

Hypothyroid subjects were identified through the Korean National Health Insurance Service Claims database between 2008 and 2017. Hypothyroidism in this study was defined as overt hypothyroidism treated with long-term prescription of levothyroxine (>6 months). After 1:3 age-, sex- and index year-matching, 501,882 patients with newly diagnosed hypothyroidism and 1,505,646 controls without hypothyroidism were included.

RESULTS

During a mean follow-up of 6 years, 25,954 (5.2%) hypothyroid patients and 59,105 (3.9%) controls died. Hypothyroidism was significantly associated with increased all-cause mortality (adjusted hazard ratio [HR], 1.14; 95% confidence interval [CI] 1.12-1.16) even with levothyroxine treatment. When stratified by age, sex, and cardiovascular disease risk, independent associations between hypothyroidism and mortality remained significant in all subgroups. The risk of mortality was higher in the < 65 age group (HR: 1.25, 95% CI: 1.22-1.29), men (HR: 1.28, 95% CI: 1.25-1.31), and the high cardiovascular disease risk group (HR: 1.31, 95% CI: 1.29-1.34). The mortality rate of hypothyroid patients was highest within 1 year of treatment and decreased with time.

CONCLUSION

This nationwide, population-based cohort study showed that all-cause mortality was significantly higher in levothyroxine-treated hypothyroid patients than in non-hypothyroid controls. This association remained significant regardless of age, sex, and cardiovascular disease risk.

Association of Thyroid Hormone Therapy with Mortality in Subclinical Hypothyroidism: A Systematic Review and Meta-Analysis

CONTEXT

Benefits of thyroid hormone therapy on mortality in adults with subclinical hypothyroidism remain undetermined.

OBJECTIVE

To summarize the impact of thyroid hormone therapy on mortality in adults with subclinical hypothyroidism.

DATA SOURCES

PubMed, Embase, Scopus, Web of Science, and Clinicaltrials.gov from inception until April 25, 2020.

STUDY SELECTION

Studies comparing the effect of thyroid hormone therapy with that of placebo or no therapy in adults with subclinical hypothyroidism on all-cause and/or cardiovascular mortality.

DATA EXTRACTION

Two reviewers independently extracted data and performed quality assessments. Random-effects models for meta-analyses were used.

DATA SYNTHESIS

Five observational studies and 2 randomized controlled trials with 21 055 adults were included. Overall, thyroid hormone therapy was not significantly associated with all-cause (pooled relative risk [RR] = 0.95, 95% confidence interval [CI]: 0.75-1.22, P = .704) or cardiovascular (pooled RR = 0.99, 95% CI: 0.82-1.20, P = .946) mortality. Subgroup analyses revealed that in younger adults (aged <65-70 years), thyroid hormone therapy was significantly associated with a lower all-cause (pooled RR = 0.50, 95% CI: 0.29-0.85, P = .011) and cardiovascular (pooled RR = 0.54, 95% CI: 0.37-0.80, P = .002) mortality. However, no significant association between thyroid hormone therapy and mortality was observed in older adults (aged ≥65-70 years).

CONCLUSIONS

Use of thyroid hormone therapy does not provide protective effects on mortality in older adults with subclinical hypothyroidism. However, thyroid hormone therapy for subclinical hypothyroidism may show benefits on morality in adults aged <65 to 70 years.

Association of Hypothyroidism and Mortality in the Elderly Population: A Systematic Review and Meta-Analysis

CONTEXT

The evidence of whether hypothyroidism increases mortality in the elderly population is currently inconsistent and conflicting.

OBJECTIVE

The objective of this meta-analysis is to determine the impact of hypothyroidism on mortality in the elderly population.

DATA SOURCES

PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases were searched from inception until May 10, 2019.

STUDY SELECTION

Studies evaluating the association between hypothyroidism and all-cause and/or cardiovascular mortality in the elderly population (ages ≥ 60 years) were eligible.

DATA EXTRACTION

Two reviewers independently extracted data and assessed the quality of the studies. Relative risk (RR) was retrieved for synthesis. A random-effects model for meta-analyses was used.

DATA SYNTHESIS

A total of 27 cohort studies with 1 114 638 participants met the inclusion criteria. Overall, patients with hypothyroidism experienced a higher risk of all-cause mortality than those with euthyroidism (pooled RR = 1.26, 95% CI: 1.15-1.37); meanwhile, no significant difference in cardiovascular mortality was found between patients with hypothyroidism and those with euthyroidism (pooled RR = 1.10, 95% CI: 0.84-1.43). Subgroup analyses revealed that overt hypothyroidism (pooled RR = 1.10, 95% CI: 1.01-1.20) rather than subclinical hypothyroidism (pooled RR = 1.14, 95% CI: 0.92-1.41) was associated with increased all-cause mortality. The heterogeneity primarily originated from different study designs (prospective and retrospective) and geographic locations (Europe, North America, Asia, and Oceania).

CONCLUSIONS

Based on the current evidence, hypothyroidism is significantly associated with increased all-cause mortality instead of cardiovascular mortality among the elderly. We observed considerable heterogeneity, so caution is needed when interpreting the results. Further prospective, large-scale, high-quality studies are warranted to confirm these findings.

Association of Subclinical Hypothyroidism and Cardiovascular Disease With Mortality

IMPORTANCE

Subclinical hypothyroidism is a common clinical entity among US adults associated in some studies with an increase in the risk of cardiovascular disease (CVD) and mortality. However, the extent to which CVD mediates the association between elevated serum thyrotropin (TSH) and mortality has not yet been well established or sufficiently quantified.

OBJECTIVE

To elucidate the extent to which subclinical hypothyroidism, elevated serum TSH and normal serum free thyroxine, or high-normal TSH concentrations (ie, upper normative-range TSH concentrations) are associated with mortality through CVD among US adults.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study relied on representative samples of US adults enrolled in the National Health and Nutrition Examination Survey in 2001 to 2002, 2007 to 2008, 2009 to 2010, and 2011 to 2012 and their mortality data through 2015. Data were analyzed from January to August 2019.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards regression models were used to investigate associations between the TSH concentration category (subclinical hypothyroidism or tertiles of serum TSH concentrations within the reference range; low-normal TSH, 0.34-1.19 mIU/L; middle-normal TSH, 1.20-1.95 mIU/L; and high-normal TSH, 1.96-5.60 mIU/L) and all-cause mortality. Mediation analysis was used within the counterfactual framework to estimate natural direct associations (not through CVD) and indirect associations (through CVD).

RESULTS

Of 9020 participants, 4658 (51.6%) were men; the mean (SD) age was 49.4 (17.8) years. Throughout follow-up (median [interquartile range], 7.3 [5.4-8.3] years), serum thyroid function test results consistent with subclinical hypothyroidism and high-normal TSH concentrations were both associated with increased all-cause mortality (subclinical hypothyroidism: hazard ratio, 1.90; 95% CI, 1.14-3.19; high-normal TSH: hazard ratio, 1.36; 95% CI, 1.07-1.73) compared with the middle-normal TSH group. Cardiovascular disease mediated 14.3% and 5.9% of the associations of subclinical hypothyroidism and high-normal TSH with all-cause mortality, respectively, with the CVD mediation being most pronounced in women (7.5%-13.7% of the association) and participants aged 60 years and older (6.0%-14.8% of the association).

CONCLUSIONS AND RELEVANCE

In this study, CVD mediated the associations of subclinical hypothyroidism and high-normal TSH concentrations with all-cause mortality in the US general population. Further studies are needed to examine the clinical benefit of thyroid hormone replacement therapy targeted to a middle-normal TSH concentration or active CVD screening for people with elevated TSH concentrations.

Outcomes of Patients With Hypothyroidism and COVID-19: A Retrospective Cohort Study

Coronavirus diseases (COVID-19) is associated with high rates of morbidity and mortality and worse outcomes have been reported for various morbidities. The impact of pre-existing hypothyroidism on COVID-19 outcomes remains unknown. The aim of the present study was to identify a possible association between hypothyroidism and outcomes related to COVID-19 including hospitalization, need for mechanical ventilation, and all-cause mortality. All patients with a laboratory confirmed COVID-19 diagnosis in March 2020 in a large New York City health system were reviewed. Of the 3703 COVID-19 positive patients included in present study, 251 patients (6.8%) had pre-existing hypothyroidism and received thyroid hormone therapy. Hypothyroidism was not associated with increased risk of hospitalization [Adjusted Odds Ratio (OR_adj): 1.23 (95% Confidence Interval (CI): 0.88- 1.70)], mechanical ventilation [OR_adj: 1.17 (95% CI: 0.81-1.69)] nor death [OR_adj: 1.07 (95% CI: 0.75-1.54)]. This study provides insight into the role of hypothyroidism on the outcomes of COVID-19 positive patients, indicating that no additional precautions or consultations are needed. However, future research into the potential complications of COVID-19 on the thyroid gland and function is warranted.

Association of Hypothyroidism With All-Cause Mortality: A Cohort Study in an Older Adult Population

CONTEXT

Although hypothyroidism is associated with many comorbidities, the evidence for its association with all-cause mortality in older adults is limited.

OBJECTIVE

To evaluate the association between hypothyroidism and all-cause mortality in older adults.

DESIGN

Population-based retrospective cohort study.

SETTING

National Health Insurance Research Database in Taiwan.

PATIENTS

After 1:10 age/sex/index year matching, 2029 patients aged ≥65 years who received a new diagnosis of hypothyroidism between 2001 and 2011 and 20,290 patients without hypothyroidism or other thyroid diseases were included in the hypothyroidism and nonhypothyroidism cohorts, respectively.

MAIN OUTCOME MEASURES

All-cause mortality was defined as the primary outcome. Cox proportional hazards regression models were used to calculate the hazard ratios of mortality. To further evaluate the effect of thyroxine replacement therapy (TRT) on mortality, we divided patients with hypothyroidism into two groups: patients who received TRT and those who did not.

RESULTS

Hypothyroidism was associated with an increased risk of all-cause mortality [adjusted hazard ratio (aHR), 1.82; 95% CI, 1.68 to 1.98; P < 0.001]. Patients with hypothyroidism who received TRT had a lower risk of mortality than patients who did not receive TRT (aHR, 0.57; 95% CI, 0.49 to 0.66; P < 0.001). Similar results were obtained after further propensity score matching in age-, sex-, and comorbidity-stratified analyses.

CONCLUSIONS

Hypothyroidism was independently associated with increased all-cause mortality in older adults. In patients with hypothyroidism, TRT was associated with a lower risk of all-cause mortality.

Subclinical Hypothyroidism and the Risk of Cardiovascular Disease and All-Cause Mortality: A Meta-Analysis of Prospective Cohort Studies

OBJECTIVES

To determine the impact of subclinical hypothyroidism (SCH) on the risk of cardiovascular disease (CVD) and all-cause mortality, a comprehensive meta-analysis was performed according to the age or coexisting CVD risk status of the participants.

METHODS

Studies regarding the association of SCH with all-cause mortality from PubMed and Embase databases were included. The pooled relative risk (RR) of CVD and all-cause mortality was calculated using the Mantel-Haenszel method. A subgroup analysis of participants with high CVD risk was conducted, including history of coronary, cerebral, or peripheral artery disease; dilated cardiomyopathy; heart failure; atrial fibrillation; venous thromboembolism; diabetes mellitus; or chronic kidney disease.

RESULTS

In total, 35 eligible articles incorporating 555,530 participants were included. SCH was modestly associated with CVD and all-cause mortality (RR for CVD = 1.33 [confidence interval (CI) 1.14-1.54]; RR for all-cause mortality = 1.20 [CI 1.07-1.34]). However, the association was not observed in participants aged ≥65 years. Subgroup analysis showed that participants with SCH and high CVD risk showed a significantly higher risk of all-cause mortality (RR for CVD = 2.20 [CI 1.28-3.77]; RR for all-cause mortality = 1.66 [CI 1.41-1.94]), whereas those with SCH and low CVD risk did not. Additional subgroup analysis of six studies with a mean participant age of ≥65 years and high CVD risk showed a significant high risk of all-cause mortality in the SCH group (RR = 1.41 [CI 1.08-1.85]; I² = 0%).

CONCLUSIONS

SCH is associated with an increased CVD risk and all-cause mortality, particularly in participants with high CVD risk.

Mortality in Children With Early-Detected Congenital Central Hypothyroidism

CONTEXT

Approximately 60% to 80% of patients with congenital central hypothyroidism (CH-C) have multiple pituitary hormone deficiencies (MPHDs), making CH-C a potentially life-threatening disease. Data on mortality in patients with CH-C are lacking.

OBJECTIVE

To study the mortality rate in pediatric patients with early-detected and treated CH-C in the Netherlands and to investigate whether causes of death were related to pituitary hormone deficiencies.

METHODS

Overall mortality rate, infant mortality rate (IMR), and under-5 mortality rate were calculated in all children with CH-C detected by neonatal screening between 1 January 1995 and 1 January 2013. Medical charts were reviewed to establish causes of death.

RESULTS

A total of 139 children with CH-C were identified, of which 138 could be traced (82 with MPHD, 56 with isolated CH-C). Total observation time was 1414 years with a median follow-up duration of 10.2 years. The overall mortality rate was 10.9% (15/138). IMR and under-5 mortality rate were 65.2/1000 (9/138) and 101.4/1000 (14/138), respectively, compared with an IMR of 4.7/1000 and under-5 mortality of 5.4/1000 live-born children in the Netherlands during the same time period (P < 0.0001). Main causes of death were severe congenital malformations in six patients, asphyxia in two patients, and congenital or early neonatal infection in two patients. Pituitary hormone deficiency was noted as cause of death in only one infant.

CONCLUSION

We report an increased mortality rate in patients with early-detected CH-C that does not seem to be related to endocrine disease. This suggests that mortality due to pituitary insufficiency is low in patients with early-detected and early-treated CH-C.

Thyroid Status and Death Risk in US Veterans With Chronic Kidney Disease

OBJECTIVE

Given that patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) have a disproportionately higher prevalence of hypothyroidism compared with their non-CKD counterparts, we sought to determine the association between thyroid status, defined by serum thyrotropin (TSH) levels, and mortality among a national cohort of patients with NDD-CKD.

PATIENTS AND METHODS

Among 227,422 US veterans with stage 3 NDD-CKD with 1 or more TSH measurements during the period October 1, 2004, to September 30, 2012, we first examined the association of thyroid status, defined by TSH categories of less than 0.5, 0.5 to 5.0 (euthyroidism), and more than 5.0 mIU/L, with all-cause mortality. We then evaluated 6 granular TSH categories: less than 0.1, 0.1 to less than 0.5, 0.5 to less than 3.0, 3.0 to 5.0, more than 5.0 to 10.0, and more than 10.0 mIU/L. We concurrently examined thyroid status, thyroid-modulating therapy, and mortality in sensitivity analyses.

RESULTS

In expanded case-mix adjusted Cox analyses, compared with euthyroidism, baseline and time-dependent TSH levels of more than 5.0 mIU/L were associated with higher mortality (adjusted hazard ratios [aHRs] [95% CI], 1.19 [1.15-1.24] and 1.23 [1.19-1.28], respectively), as were baseline and time-dependent TSH levels of less than 0.5 mIU/L (aHRs [95% CI], 1.18 [1.15-1.22] and 1.41 [1.37-1.45], respectively). Granular examination of thyroid status showed that incrementally higher TSH levels of 3.0 mIU/L or more were associated with increasingly higher mortality in baseline and time-dependent analyses, and TSH categories of less than 0.5 mIU/L were associated with higher mortality (reference, 0.5-<3.0 mIU/L) in baseline analyses. In time-dependent analyses, untreated and undertreated hypothyroidism and untreated hyperthyroidism were associated with higher mortality (reference, spontaneous euthyroidism), whereas hypothyroidism treated-to-target showed lower mortality.

CONCLUSION

Among US veterans with NDD-CKD, high-normal TSH (≥3.0 mIU/L) and lower TSH (<0.5 mIU/L) levels were associated with higher death risk. Interventional studies identifying the target TSH range associated with the greatest survival in patients with NDD-CKD are warranted.

Over- and Under-Treatment of Hypothyroidism Is Associated with Excess Mortality: A Register-Based Cohort Study

OBJECTIVE

This study investigated the association between hypothyroidism and mortality in both treated and untreated hypothyroid patients, and the consequences of over- and under-treatment with respect to mortality.

PATIENTS AND METHODS

This was a register-based cohort study of 235,168 individuals who had at least one serum thyrotropin (TSH) during 1995-2011 (median follow-up 7.2 years). Hypothyroidism was defined as at least two measurements of TSH >4.0 mIU/L within a half year spaced by at least 14 days, or one measurement of TSH >4.0 mIU/L and two filled prescriptions of levothyroxine the following year. All-cause mortality rates were calculated using multivariable Cox regression analysis adjusted for age, sex, and comorbidities using the Charlson Comorbidity Index.

RESULTS

Mortality was increased in untreated hypothyroid individuals (n = 673; hazard ratio [HR] = 1.46 [confidence interval (CI) 1.26-1.69]; p < 0.001) compared to euthyroid controls. Results remained significant even when subdividing according to mild (TSH >4.0 mIU/L and ≤10 mIU/L; p < 0.001) and marked hypothyroidism (TSH >10 mIU/L; p = 0.002). Mortality was increased in both treated and untreated hypothyroid individuals for each six months a patient had increased TSH (HR = 1.05 [CI 1.02-1.07], p < 0.0001, and HR = 1.05 [CI 1.02-1.07], p = 0.0009, respectively). In patients who received levothyroxine, the HR for mortality increased by a factor 1.18 ([CI 1.15-1.21]; p < 0.0001) for each six months a patient exhibited decreased TSH. This finding was essentially unchanged after stratification by disease severity (mild or marked hypothyroidism) and age (older and younger than 65 years).

CONCLUSIONS

Mortality was increased in untreated but not in treated hypothyroid individuals, independently of age and severity of hypothyroidism. Duration of decreased TSH in treated individuals had a greater impact on mortality than did duration of elevated TSH. These results stress the need for close monitoring of treatment in individuals receiving thyroid hormone replacement therapy.

Treatment with levothyroxin in subclinical hypothyroidism is associated with increased mortality in the elderly

INTRODUCTION

It is uncertain whether subclinical hypothyroidism should be treated with levothyroxine, particularly in the elderly. This study evaluated the association between levothyroxine treatment and mortality in individuals 65years or older with subclinical hypothyroidism and TSH values <10mIU/L.

METHODS

A case-control study in which patients 65years or older with TSH levels of 4.2-10mIU/L who died in the years 2012-2016 ('cases') were compared with matched individuals who did not die during this period ('controls'). Matching was based on gender, age, Charlson comorbidity index, date of TSH testing, duration of follow-up and TSH quartile. All cases of known thyroid disease or cases in which anti-thyroid medications or glucocorticoids were dispensed in the year preceding the TSH evaluation were excluded. Use of levothyroxine was compared between groups.

RESULTS

During the follow-up period, 419 individuals died and these were matched with 1558 individuals who did not. Factors found to be associated with mortality were age, senile dementia, congestive heart failure, chronic renal failure and a history of cerebrovascular disease. On multivariate analysis, treatment with levothyroxine was associated with significantly increased mortality (HR=1.19 CI 1.03-1.38). Femoral fractures and atrial fibrillation following initiation of levothyroxine therapy were not more prevalent in individuals who died during the follow-up period.

CONCLUSIONS

Treatment with levothyroxine is associated with significantly increased mortality in individuals 65years or older with subclinical hypothyroidism and TSH<10.

Hypothyroidism During Tyrosine Kinase Inhibitor Therapy Is Associated with Longer Survival in Patients with Advanced Nonthyroidal Cancers

BACKGROUND

Tyrosine kinase inhibitor (TKI)-induced thyroid dysfunction is recognized as a common adverse effect of treatment, but the importance of incident hypothyroidism during TKI therapy remains unclear. This study analyzed the prognostic significance of hypothyroidism during TKI therapy in cancer patients.

METHODS

This was a retrospective cohort study of adult patients with advanced nonthyroidal cancer treated with TKI and available thyroid function testing at three affiliated academic hospitals from 2000 to 2017. Patients with preexisting thyroid disease were excluded. Demographic, clinical, and cancer treatment data were collected. Thyroid status with TKI treatment was determined from thyroid function testing and initiation of thyroid medication, and classified as euthyroid (thyrotropin [TSH] normal), subclinical hypothyroidism (SCH; TSH 5-10 mIU/L, or higher TSH if free thyroxine normal), or overt hypothyroidism (OH; TSH >10 mIU/L, low free thyroxine, or requiring replacement). Multivariate models were used to evaluate the effect of TKI-related hypothyroidism on overall survival (OS).

RESULTS

Of 1120 initial patients, 538 remained after exclusion criteria. SCH occurred in 72 (13%) and OH in 144 (27%) patients with TKI therapy. Patients with hypothyroidism had significantly longer OS, with median OS in euthyroid patients of 685 days [confidence interval (CI) 523-851] compared to 1005 days [CI 634-1528] in SCH and 1643 days [CI 1215-1991] in OH patients (p < 0.0001). After adjustment for age, sex, race/ethnicity, cancer type, cancer stage, ECOG performance status, and checkpoint inhibitor therapy, OH remained significantly associated with OS (hazard ratio = 0.561; p < 0.0001), whereas SCH did not (hazard ratio = 0.796; p = 0.165). Analysis of hypothyroid patients (SCH and OH) with TSH >5 and <10 mIU/L stratified by hormone replacement status showed improved survival associated with hormone replacement.

CONCLUSIONS

New hypothyroidism in cancer patients treated with TKI is associated with significantly improved OS, should not necessitate TKI dose reduction or discontinuation, and may provide independent prognostic information.

Pre-admission TSH levels predict long-term mortality in adults treated for hypothyroidism

CONTEXT

Limited data is available regarding the association between pre-admission thyroid function and prognosis of hospitalized patients treated for hypothyroidism.

OBJECTIVE

Evaluate an association between thyroid stimulating hormone (TSH) levels and mortality in hospitalized levothyroxine-treated patients.

DESIGN AND SETTING

Observational data of patients admitted to medical wards between 2011 and 2013. TSH levels obtained up to 180 days prior to admission were stratified as follows: low (≤0.5 mIU/L), normal (0.5-5 mIU/L), high (>5 mIU/L).

PATIENTS

Patients aged 60-80 years with available thyroid function tests were matched with controls without hypothyroidism.

MAIN OUTCOME

All-cause mortality up to 66-months following discharge.

RESULTS

One thousand and fifty seven patients (73% females, mean (SD) age 71 ± 6 years) were matched with controls without hypothyroidism. Mean hospital stay and in-hospital mortality were not different between groups. Mortality risk at the end-of-follow-up was 41% (438/1057) and 37% (392/1057) for patients with and without hypothyroidism (p < 0.05). TSH levels were classified as follows: low, 84 patients (8%); normal, 667 patients (63%); high, 306 patients (29%). Length of hospitalization and in-hospital mortality were not different between TSH categories. Mortality risk at the end-of-follow-up was 30, 39, and 50% with low, normal and elevated TSH, respectively. Adjusted hazard ratio (95% CI) of mortality at the end-of-follow-up was of 2.2 (1.2-3.8) for high vs. low TSH levels, and 1.4 (1.1-1.9) for high vs. normal TSH levels.

CONCLUSION

In treated hypothyroid adult patients, increased TSH up to 6 months prior to admission is associated with increased mortality. Treatment should aim at achieving euthyroidism to improve survival.

Hypothyroidism in hospitalized elderly patients: a sign of worse prognosis

PURPOSE

Overt hypothyroidism has adverse clinical consequences and might worsen prognosis in critically ill elderly patients. However, the difficult interpretation of thyroid function tests (TFT) due to non-thyroidal illness (NTI) has led to discouragement of screening for thyroid dysfunction. Our aim was to determine the prevalence of TFT compatible with hypothyroidism and to study its influence on mortality among hospitalized elderly patients.

METHODS

In this prospective study we consecutively included all patients ≥60 years admitted by the Internal Medicine Department to the hospital ward (n = 451) of the Cesar Milstein Hospital in Buenos Aires, Argentina. TFT were done on day 1 and 8. Thyroid function categories were defined as overt and subclinical hypothyroidism, overt and subclinical hyperthyroidism, euthyroidism and NTI. Stage of chronic kidney disease (CKD), Adult Comorbidity Evaluation (ACE)-27, and intra-hospital mortality were recorded. The association between mortality and TFT categories was studied by Cox regression.

RESULTS

Out of 451 patients (77.0 ± 7.9 years, 54% females) 76% were categorized as NTI, 4% as overt hypothyroid, 10% as subclinical hypothyroid, 1% as subclinical hyperthyroid and 9% as euthyroid. Overt hypothyroid patients showed significantly higher mortality than the rest of the groups (25%, p < 0.05) while ACE-27 was similar among all of them (p = 0.658). In addition, patients within the overt hypothyroid category showed a higher mortality rate than NTI in a model adjusted by Stage 5-CKD, ACE-27, sex and age [HR 3.1 (1.14-8.41), p < 0.026].

CONCLUSION

Overt hypothyroidism during hospitalization was associated with elevated mortality. Further studies would reveal if TFT alterations compatible with hypothyroidism should be diagnosed/treated in hospitalized elderly patients.

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.

Elevated TSH in adults treated for hypothyroidism is associated with increased mortality

CONTEXT

Numerous studies investigated the link between hypothyroidism and mortality, but a definite conclusion is hard to reach as these were limited by a number of factors, including age of participants, comorbidities and single measurement of thyroid function.

OBJECTIVE

To evaluate the association between TSH and fT4 levels and mortality in patients with levothyroxine-treated hypothyroidism.

DESIGN AND SETTING

Observational data of hospitalized patients (2011-2014). TSH and fT4 levels obtained between at least 30 days after discharge and until death or end of follow-up were collected. Median TSH and fT4 levels were stratified into categories.

PATIENTS

In total, 611 patients with treated hypothyroidism, aged 60-80 years (72% females, mean age 71 ± 6 years) were included in the study.

MAIN OUTCOME MEASURE

All-cause mortality up to 66 months after discharge, by TSH and fT4 categories.

RESULTS

During follow-up, the average numbers of TSH and fT4 measurements were 5.5 ± 3.8 and 2.5 ± 4.2 per patient respectively. Mortality rates were 28%, 29% and 54% with median TSH of 0.5-2.5, 2.5-5.0 and 5.0-10.0 IU/L respectively. Adjusted hazard ratios for mortality with median TSH between 5.0 and 10.0 IU/L were 2.3 (95% CI: 1.6-3.4) and 2.2 (95% CI: 1.6-3.2) compared with patients with TSH between 0.5-2.5 IU/L and 2.5-5 IU/L respectively. There was no difference in mortality between patients with median fT4 10-15 or 15-20 pmol/L.

CONCLUSION

In treated hypothyroid adult patients and serial measurements of thyroid function tests, median TSH levels of 5-10 IU/L are associated with increased mortality with no effect of fT4 levels. Treatment should aim at achieving euthyroidism to improve survival.

Thyroid Functional Disease and Mortality in a National Peritoneal Dialysis Cohort

CONTEXT AND OBJECTIVE

End-stage renal disease patients have a higher risk of thyroid disease compared with those without kidney disease. Although thyroid dysfunction is associated with higher death risk in the general population and those undergoing hemodialysis, little is known about the effect of thyroid disease upon mortality in patients treated with peritoneal dialysis (PD).

DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME

We examined the association of thyroid status, assessed by serum TSH, with all-cause mortality among PD patients from a large national dialysis organization who underwent one or more TSH measurements over 5 years (January 2007 to December 2011). Thyroid status was categorized as overt-hyperthyroid, subclinical-hyperthyroid, low-normal, high-normal, subclinical-hypothyroid, and overt-hypothyroid range (TSH < 0.1, 0.1–<0.5, 0.5–<3.0, 3.0–<5.0, 5.0–<10.0, and ≥10.0 mIU/L, respectively). We examined the association between TSH and mortality using case mix–adjusted time-dependent Cox models to assess short-term thyroid function–mortality associations and to account for changes in thyroid function over time.

RESULTS

Among 1484 patients, 7 and 18% had hyperthyroidism and hypothyroidism, respectively, at baseline. We found that both lower and higher time-dependent TSH levels were associated with higher mortality (reference: TSH, 0.5-<3.0 mIU/L): adjusted hazard ratios (95% confidence intervals) 2.09 (1.08-4.06), 1.53 (0.87-2.70), 1.05 (0.75-1.46), 1.63 (1.11-2.40), and 3.11 (2.08-4.63) for TSH levels, <0.1, 0.1-<0.5, 0.5-<3.0, 3.0-<5.0, 5.0-<10.0, and ≥10.0 mIU/L, respectively.

CONCLUSION

Time-dependent TSH levels < 0.1 mIU/L and ≥ 5.0 mIU/L were associated with higher mortality, suggesting hyper- and hypothyroidism carry short-term risk in PD patients. Additional studies are needed to determine mechanisms underlying the thyroid dysfunction-mortality association, and whether normalization of TSH with treatment ameliorates mortality in this population.

Association Between Serum Thyrotropin Levels and Mortality Among Euthyroid Adults in the United States

BACKGROUND

Low thyroid function within the euthyroid range, as well as overt and subclinical hypothyroidism, reportedly increases the risk of cardiovascular disease and mortality. However, the association between low normal thyroid function and mortality remains controversial. This study was performed to elucidate the association between low normal thyroid function and all-cause and/or cause-specific mortalities among U.S. adults.

METHODS

A prospective cohort study was conducted using a nationally representative sample of 12,584 U.S. adults aged ≥20 years with thyrotropin (TSH) levels within the reference range from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994). Associations between TSH tertiles (high, medium, and low normal TSH groups) and mortalities (all-cause, cardiovascular, and cancer) were investigated using multivariable Cox models. Stratum-specific analyses were estimated within subgroups defined according to sex (male or female) and baseline age (age <60 years or age ≥60 years). Further, the same analysis was conducted using continuous NHANES 2001-2002, 2007-2008, and 2009-2010 cohorts, which included data on free thyroxine levels.

RESULTS

The median follow-up period was 19.1 years, with 3395 all-cause deaths. A significantly higher risk of all-cause mortality (adjusted hazard ratio [HR] 1.27; [confidence interval (CI) 1.10-1.47]), and cardiovascular mortality (HR 1.30 [CI 1.02-1.67]), and cancer mortality (HR 1.43 [CI 1.01-2.01]) was observed in the high normal TSH group than in the medium normal TSH group. Additionally, the low normal TSH group had an increased risk of all-cause mortality. In stratum-specific analyses, a significant association was found between high normal TSH levels and all-cause mortality among males, females, and participants <60 years. Continuous NHANES cohorts demonstrated a non-significant increase in the HR for all-cause mortality in the high normal TSH group.

CONCLUSIONS

High normal TSH levels compared with medium normal TSH levels were associated with increased risk of all-cause, cardiovascular, and cancer mortalities over a long-term follow-up period among U.S. adults. This study indicates that the reference range for TSH levels may require re-evaluation.

Subclinical Hypothyroidism in Childhood Cancer Survivors

PURPOSE

In childhood cancer survivors, the most common late effect is thyroid dysfunction, most notably subclinical hypothyroidism (SCH). Our study evaluated the risk factors for persistent SCH in survivors.

MATERIALS AND METHODS

Survivors (n=423) were defined as patients who survived at least 2 years after cancer treatment completion. Thyroid function was assessed at this time and several years thereafter. Two groups of survivors with SCH were compared: those who regained normal thyroid function during the follow-up period (normalized group) and those who did not (persistent group).

RESULTS

Overall, 104 of the 423 survivors had SCH. SCH was observed in 26% of brain or nasopharyngeal cancer survivors (11 of 43) and 21.6% of leukemia survivors (35 of 162). Sixty-two survivors regained normal thyroid function, 30 remained as persistent SCH, and 12 were lost to follow-up. The follow-up duration was 4.03 (2.15-5.78) years. Brain or nasopharyngeal cancer and Hodgkin disease were more common in the persistent group than in the normalized group (p=0.002). More patients in the persistent group received radiation (p=0.008). Radiation to the head region was higher in this group (2394±2469 cGy) than in the normalized group (894±1591 cGy; p=0.003). On multivariable analysis, lymphoma (p=0.011), brain or nasopharyngeal cancer (p=0.039), and head radiation dose ≥1800 cGy (p=0.039) were significant risk factors for persistent SCH.

CONCLUSION

SCH was common in childhood cancer survivors. Brain or nasopharyngeal cancer, lymphoma, and head radiation ≥1800 cGy were significant risk factors for persistent SCH.

Subclinical hypothyroidism and mortality in a large Austrian cohort: a possible impact on treatment?

BACKGROUND

Clinical implications of subclinical hypothyroidism (SCH) are still matter of intense debate, resulting in the controversial discussion whether subclinical hypothyroidism should be treated. We performed a cohort study to evaluate the impact of subclinical hypothyroidism on vascular and overall mortality.

METHODS

Between 02/1993 and 03/2004, a total of 103,135 persons attending the General Hospital Vienna with baseline serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxin (fT4) measurements could be enrolled in a retrospective cohort study. Subclinical hypothyroidism was defined by elevated TSH ranging from 4.5 to 20.0 mIU/L and normal fT4 concentration (0.7-1.7 ng/dL). Overall and vascular mortality as primary endpoints were assessed via record linkage with the Austrian Death Registry.

RESULTS

A total of 80,490 subjects fulfilled inclusion criteria of whom 3934 participants (3.7%) were classified as SCH (868 males and 3066 females, median age 48 years). The mean follow-up among the 80,490 subjects was 4.1 years yielding an observation period of 373,301 person-years at risk. In a multivariate Cox regression model adjusted for age and gender TSH levels showed a dose-dependent association with all-cause mortality. The association between SCH and overall or vascular mortality was stronger in men below 60 years compared to older males or females.

CONCLUSION

Our data support the hypothesis that SCH might represent an independent risk factor for overall and vascular mortality, especially in men below 60 years. Whether this group would benefit from replacement therapy should be evaluated in interventional studies.

Risk factors for mortality in Down syndrome

BACKGROUND

Down syndrome is a genetic condition that contributes to a significantly shorter life expectancy compared with the general population. We investigated the most common comorbidities in a population of acute hospital patients with Down syndrome and further explored what the most common risk factors for mortality are within this population.

METHOD

From our database of one million patients admitted to National Health Service (NHS) Trusts in northern England, we identified 558 people who had Down syndrome. We compared this group with an age- and gender-matched control group of 5580 people.

RESULTS

The most prevalent comorbid diseases within the Down's population were hypothyroidism (22.9%) and epilepsy (20.3%). However, the conditions that had the highest relative risks (RRs) in the Down's population were septal defects and dementia. Respiratory failure, dementia and pneumonia were the most significantly related comorbidities to mortality in the Down syndrome population. In the control population, respiratory failure, dementia and renal failure were the most significant disease contributors. When these contributors were analysed using multivariate analysis, heart failure, respiratory failure, pneumonia and epilepsy were the identified risk factors for in-hospital mortality in the Down syndrome population. Respiratory failure was the sole risk factor for mortality in the Down syndrome population [RR = 9.791 (1.6-59.9) P ≤ 0.05], when compared with the risk factors for mortality in the control population.

CONCLUSIONS

There is significant medical morbidity in Down syndrome. This morbidity contributes to the lower life expectancy. Respiratory failure is a risk factor for mortality in Down syndrome. We need to thoroughly investigate people with Down syndrome to ensure any treatable illnesses are well managed.

Low Triiodothyronine Syndrome and Long-Term Cardiovascular Outcome in Incident Peritoneal Dialysis Patients

BACKGROUND AND OBJECTIVES

A direct association between low triiodothyronine (T3) syndrome and cardiovascular (CV) mortality has been reported in hemodialysis patients. However, the implications of this syndrome in peritoneal dialysis (PD) patients have not been properly investigated. This study examined the association between low T3 syndrome and CV mortality including sudden death in a large cohort of incident PD patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This prospective observational study included 447 euthyroid patients who started PD between January 2000 and December 2009. Measurement of thyroid hormones was performed at baseline. All-cause and cause-specific deaths were registered during the median 46 months of follow-up. The survival rate was compared among three groups based on tertile of T3 levels.

RESULTS

In Kaplan-Meyer analysis, patients with the lowest tertile were significantly associated with higher risk of all-cause and CV mortality including sudden death (P<0.001 for trend). In Cox analyses, T3 level was a significant predictor of all-cause mortality (per 10-unit increase, adjusted hazard ratio [HR], 0.86; 95% confidence interval [95% CI], 0.78 to 0.94; P=0.002), CV death (per 10-unit increase, adjusted HR, 0.84; 95% CI, 0.75 to 0.98; P=0.01), and sudden death (per 10-unit increase, adjusted HR, 0.69; 95% CI, 0.56 to 0.86; P=0.001) after adjusting for well known risk factors including inflammation and malnutrition. The higher T3 level was also independently associated with lower risk for sudden death (per 10-unit increase, adjusted HR, 0.71; 95% CI, 0.56 to 0.90; P=0.01) even when accounting for competing risks of death from other causes.

CONCLUSIONS

T3 level at the initiation of PD was a strong independent predictor of long-term CV mortality, particularly sudden death, even after adjusting well known risk factors. Low T3 syndrome might represent a factor directly implicated in cardiac complications in PD patients.

Association of thyroid functional disease with mortality in a national cohort of incident hemodialysis patients

CONTEXT

Hypothyroidism is a common condition that disproportionately affects hemodialysis patients. In the general population, hypothyroidism is associated with higher mortality, particularly in populations with underlying cardiovascular risk. Despite their heightened cardiovascular mortality, the impact of hypothyroidism on the survival of hemodialysis patients remains uncertain.

OBJECTIVE

To examine whether hypothyroidism is independently associated with higher mortality in hemodialysis patients.

DESIGN, SETTING, AND PATIENTS

Among 8840 incident hemodialysis patients receiving care from a large national dialysis provider from January 2007 to December 2011, we examined the association of hypothyroidism (TSH >5.0 mIU/L) with mortality.

MAIN OUTCOME MEASURES

Associations between baseline and time-dependent hypothyroidism with all-cause mortality were determined using case-mix adjusted Cox models. In secondary analyses, we examined the impact of low-normal, upper-normal, subclinical range, and overt range TSH levels (TSH ≥ 0.5-3.0, >3.0-5.0, >5.0-10.0, and >10.0 mIU/L, respectively) on mortality risk.

RESULTS

The study population consisted of 1928 (22%) hypothyroid and 6912 (78%) euthyroid patients. Baseline and time-dependent hypothyroidism were associated with higher mortality: adjusted hazard ratios (95% confidence intervals) were 1.47 (1.34-1.61) and 1.62 (1.45-1.80), respectively. Compared to low-normal TSH, upper-normal, subclinical hypothyroid, and overt hypothyroid TSH levels were associated with incrementally higher adjusted death risk in baseline and time-dependent analyses. In time-dependent analyses, the hypothyroidism-mortality association was increasingly stronger across higher body mass index strata.

CONCLUSIONS

Hypothyroidism as well as upper-normal TSH levels are associated with higher mortality in hemodialysis patients. Further studies are needed to determine whether restoration of TSH to low-normal levels with thyroid hormone replacement therapy ameliorates adverse outcomes in hemodialysis patients.

Subclinical hypothyroidism is associated with increased risk for cancer mortality in adult Taiwanese-a 10 years population-based cohort

BACKGROUND

The association between subclinical hypothyroidism (SCH) and cancer mortality is seldom discussed.

METHODS

A total of 115,746 participants without thyroid disease history, aged 20 and above, were recruited from four nationwide health screening centers in Taiwan from 1998 to 1999. SCH was defined as a serum thyroid-stimulating hormone (TSH) level of 5.0-19.96 mIU/L with normal total thyroxine concentrations. Euthyroidism was defined as a serum TSH level of 0.47-4.9 mIU/L. Cox proportional hazards regression analyses were used to estimate the relative risks (RRs) of death from cancer for adults with SCH during a 10-year follow-up period.

RESULTS

Among 115,746 adults, 1,841 had SCH (1.6%) and 113,905 (98.4%) had euthyroidism. There were 1,532 cancer deaths during the 1,034,082 person-years follow-up period. Adjusted for age, gender, body mass index, diabetes, hypertension, dyslipidemia, smoking, alcohol drinking, betel nut chewing, physical activity, income, and education level, the RRs (95% confidence interval) of cancer deaths among subjects with SCH versus euthyroid subjects were 1.51 (1.06 to 2.15). Cancer site analysis revealed a significant increased risk of bone, skin and breast cancer among SCH subjects (RR 2.79, (1.01, 7.70)). The risks of total cancer deaths were more prominent in the aged (RR 1.71, (1.02 to 2.87)), in females (RR 1.69 (1.08 to 2.65)), and in heavy smokers (RR 2.24, (1.19 to 4.21)).

CONCLUSIONS

Subjects with SCH had a significantly increased risk for cancer mortality among adult Taiwanese. This is the first report to demonstrate the association between SCH and cancer mortality.

Medically induced euthyroid hypothyroxinemia may extend survival in compassionate need cancer patients: an observational study

BACKGROUND

Clinical studies have shown that interventional lowering of serum free thyroxine (FT4) may be associated with extended survival in patients with some terminal cancers. The report of success with this approach in glioblastoma multiforme caused involvement of the author (A.H.) in the prospective consultative management of 23 end-stage solid tumor patients in whom hypothyroxinemia was induced to prolong life.

PATIENTS AND METHODS

Patients were self-referred or recommended by attending physicians to the author (A.H.) and had advanced cancers of the brain, ovary, lung, pancreas, salivary gland, and breast or had mesothelioma or soft-tissue sarcoma. Hypothyroxinemia was achieved in euthyroid patients by using methimazole, with the addition of 3,3',5-triiodo-L-thyronine (L-T3) to prevent hypothyroidism and suppress endogenous thyrotropin (TSH). In patients with pre-existent primary hypothyroidism, T3 administration was substituted for T4 replacement. Serum FT4 and TSH concentrations were serially monitored to enable adjustments to drug therapy and prevent clinical hypothyroidism. Survival was measured from the date of hypothyroxinemia induction with T3 or methimazole plus T3. Outcomes were compared with the odds of death based on the Surveillance Epidemiology and End Results and American Joint Committee on Cancer databases and literature reports.

RESULTS

The survival time of 83% (19 of 23) of patients exceeded the 20% expected 1-year survival for this hypothyroxinemic, end-stage cancer group. The difference between actual and expected survival was significant.

CONCLUSION

Although this is an uncontrolled observational experience with frank limitations, compassionate medical induction of hypothyroxinemia should be considered for patients with advanced cancers to whom other avenues of treatment are closed.

Thyroid antibody status, subclinical hypothyroidism, and the risk of coronary heart disease: an individual participant data analysis

CONTEXT

Subclinical hypothyroidism has been associated with increased risk of coronary heart disease (CHD), particularly with thyrotropin levels of 10.0 mIU/L or greater. The measurement of thyroid antibodies helps predict the progression to overt hypothyroidism, but it is unclear whether thyroid autoimmunity independently affects CHD risk.

OBJECTIVE

The objective of the study was to compare the CHD risk of subclinical hypothyroidism with and without thyroid peroxidase antibodies (TPOAbs).

DATA SOURCES AND STUDY SELECTION

A MEDLINE and EMBASE search from 1950 to 2011 was conducted for prospective cohorts, reporting baseline thyroid function, antibodies, and CHD outcomes.

DATA EXTRACTION

Individual data of 38 274 participants from six cohorts for CHD mortality followed up for 460 333 person-years and 33 394 participants from four cohorts for CHD events.

DATA SYNTHESIS

Among 38 274 adults (median age 55 y, 63% women), 1691 (4.4%) had subclinical hypothyroidism, of whom 775 (45.8%) had positive TPOAbs. During follow-up, 1436 participants died of CHD and 3285 had CHD events. Compared with euthyroid individuals, age- and gender-adjusted risks of CHD mortality in subclinical hypothyroidism were similar among individuals with and without TPOAbs [hazard ratio (HR) 1.15, 95% confidence interval (CI) 0.87-1.53 vs HR 1.26, CI 1.01-1.58, P for interaction = .62], as were risks of CHD events (HR 1.16, CI 0.87-1.56 vs HR 1.26, CI 1.02-1.56, P for interaction = .65). Risks of CHD mortality and events increased with higher thyrotropin, but within each stratum, risks did not differ by TPOAb status.

CONCLUSIONS

CHD risk associated with subclinical hypothyroidism did not differ by TPOAb status, suggesting that biomarkers of thyroid autoimmunity do not add independent prognostic information for CHD outcomes.

Thyroid dysfunction and ischemic heart disease--clinical correlations, progressive implications and impact on the prognosis

Thyroid dysfunctions are associated with systolic and diastolic heart dysfunction, hypertension, rhythm disorders, etc. Clinically significant hyperthyroidism and hypothyroidism may have an impact on the patients with ischemic heart disease.

OBJECTIVES

Investigation of the risk of developing ischemic heart disease, of the evolution and prognosis in relation to the entire spectrum of thyroid dysfunctions.

MATERIALS AND METHODS

All participants included in the study were selected from among subjects with heart disorders who were controlled with concern to the thyroid hormonal condition and who hadn't been treated previously for thyroid functional disorders. Based on these criteria we defined a study group made out of 791 subjects, divided into five lots based on the level of thyroid hormones. Once the group was formed, we conducted evaluations of the cardiovascular and thyroid status at 6 and 12 months, respectively.

RESULTS

In the witness lot, during monitoring 49% of the patients showed an ischemic heart disease. The main risk factors were: heart frequency of over 80 beats/min (RR = 1.83), age over 60 (RR = 1.47), female sex (RR = 1.21) and values of triglycerides over 160 mg/dl (RR = 1.23). In the group of patients with overt clinic hyperthyroidism, during monitoring 46.1% showed ischemic heart disease. The main risk factors were: heart frequency over 80 beats/min (RR = 2.41), age over 60 (RR = 1.67), high level of LDL-cholesterol (RR = 1.53) and female sex (RR = 1.31). Among the patients with overt clinical hyperthyroidism, during monitoring 53.3% showed ischemic heart disease. The main risk factors identified were: heart frequency over 80 beats/min (RR = 2.01), age over 60 (RR = 1.42), high levels of triglycerides (RR = 1.42) and LDL-cholesterol (RR = 1.32), as well as the presence of hypertension in the health records (RR = 1.31).

CONCLUSIONS

Thyroid dysfunction is a common clinical condition with a key role in the regulation of the cardiovascular system and may contribute to the evolution of the ischemic heart disease and which should be taken into consideration when patients with heart disease are treated. In this light, thyroid function needs to be evaluated for all patients with a risk for ischemic heart disease.

Thyroid function tests and mortality in aged hospitalized patients: a 7-year prospective observational study

CONTEXT

Several alterations in thyroid function test (TFT) results have been associated with mortality in elderly patients.

OBJECTIVE

Our aim was to investigate the relationship between TFT results and all-cause and cardiovascular (CV) mortality in aged hospitalized patients.

DESIGN

A 7-year prospective observational study was conducted. TFTs were performed at hospital admission, and mortality was registered in the follow-up period.

PATIENTS

Participants were 404 patients aged >65 years admitted to the Department of Geriatrics, Hospital General, Segovia, Spain, for any reason during 2005.

MAIN OUTCOME MEASURES

The study evaluated the association between TFT results and mortality from all causes and CV diseases.

METHODS

TSH, free T₄, and free T₃ (FT₃) were measured on the first day of admission. In-hospital and total survival times, number of deaths, and all-cause and CV mortality were registered until the census date on January 1, 2012.

RESULTS

During the study, 323 patients (80%) died. Kaplan-Meier analysis showed that median survival time for all-cause mortality was significantly lower in patients in the first tertile of serum FT₃, in the first tertile of TSH, and in the first tertile of serum free T₄ concentrations. Multivariate adjusted Cox regression analysis showed that the history of cancer (hazard ratio, 1.60; 95% confidence interval, 1.12-2.28; P = .009), age (1.03; 1.01-1.06; P = .003), and FT₃ levels (0.72; 0.63-0.84; P < .001) were significant factors related to all-cause mortality. The cause of death was known in 202 patients. Of this group, 61 patients (30.2%) died of CV disease. Patients in the first tertile of TSH and FT₃ exhibited a significant higher mortality due to CV disease. In the adjusted Cox regression analysis, FT₃ was a significant predictor of CV mortality (0.76; 0.63-0.91; P = .004).

CONCLUSIONS

Alterations in TFT results during hospitalization are associated with long-term mortality in elderly patients. In particular, low FT₃ levels are significantly related to all-cause and CV mortality.

Higher free thyroxine levels are associated with all-cause mortality in euthyroid older men: the Health In Men Study

OBJECTIVE

Thyroid dysfunction predicts poorer health outcomes, but the relationship between thyroid hormone levels within the reference range and mortality in older adults remains unclear. In this study, we examined the associations between the concentrations of free thyroxine (FT4) and TSH and all-cause mortality in older men without thyroid disease.

SUBJECTS AND METHODS

We performed a longitudinal study in community-dwelling men aged 70-89 years. Men with thyroid disease or taking thyroid-related medications were excluded. Baseline FT4 and TSH levels were assayed. Incident deaths were ascertained using data linkage.

RESULTS

There were 3885 men without thyroid disease followed for (means.d.) 6.41.5 years, during which time 837 had died (21.5%). men who had died had higher baseline ft4 levels (16.22.3 vs 15.82.1 pmol/l, p0.001), but comparable tsh levels (2.41.5 vs 2.31.5 miu/l, P=0.250). After accounting for age, smoking, physical factors and medical comorbidities, higher circulating ft4 levels predicted all-cause mortality (quartile Q4 vs quartiles Q1Q3: FT4 levels ≥ 17.32 vs <17.32 pmol/l: adjusted hazard ratio (HR)=1.19, 95% CI=1.02-1.39, P=0.025). TSH levels did not predict mortality. After excluding men with subclinical hyperthyroidism or hypothyroidism, there were 3442 men and 737 who had died (21.4%). In these men, higher FT4 levels remained independently associated with all-cause mortality (quartile Q4 vs quartiles Q1-Q3: adjusted HR=1.19, 95% CI=1.02-1.41, P=0.032).

CONCLUSIONS

Higher FT4 levels are associated with all-cause mortality in euthyroid older men, independently of conventional risk factors and medical comorbidities. Additional research is needed to determine whether or not this relationship is causal and to clarify the utility of thyroid function testing to stratify mortality risk in ageing men.

Subclinical hypothyroidism and survival: the effects of heart failure and race

CONTEXT

Studies examining the association between subclinical hypothyroidism and mortality have yielded conflicting results. Emerging data suggest these associations may depend upon underlying congestive heart failure (CHF) and/or race, but this has not been empirically determined.

OBJECTIVE

Our objective was to examine the association between subclinical hypothyroidism and hypothyroidism overall with mortality according to pre-existing CHF and race.

DESIGN AND PARTICIPANTS

We examined the associations of subclinical hypothyroidism (TSH higher than assay upper limit of normal; total T4 within reference) and hypothyroidism overall (TSH higher than assay upper limit of normal; total T4 below lower limit of normal or within reference) with all-cause mortality among Third National Health and Nutrition Examination Survey participants stratified by CHF and race using multivariable Cox models. To confirm whether differences between strata were statistically significant, we tested for interaction on the basis of CHF (separately) and race by likelihood ratio testing.

RESULTS

There were 14 130 (95.0%) euthyroid controls and 749 (5.0%) participants with hypothyroidism, 691 (4.6%) of whom had subclinical disease. Subclinical hypothyroidism vs euthyroidism was associated with greater mortality in those with CHF but not in those without: adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) = 1.44 (1.01-2.06) and 0.97 (0.85-1.11), respectively (P interaction = .03). Similar findings were observed for hypothyroidism overall. Hypothyroidism overall vs euthyroidism was associated with greater mortality in Black participants (HR = 1.44 [95% CI = 1.03-2.03]) but not in non-Blacks (HR = 0.95 [95% CI = 0.83-1.08]) (P interaction = .03).

CONCLUSION

Among participants with CHF, subclinical hypothyroidism and hypothyroidism overall are associated with greater death risk. Additional studies are needed to confirm findings and explore possible mechanisms for the differential hypothyroidism-mortality association across race.

Death rates for acquired hypothyroidism and thyrotoxicosis in English populations (1979-2010): comparison of underlying cause and all certified causes

BACKGROUND

Overt hypothyroidism and thyrotoxicosis have widespread systemic effects and are associated with increased mortality. Most death certificates that include them do not have the thyroid disease coded as the underlying cause of death.

AIM

To describe regional (1979-2010) and national (1995-2010) trends in mortality rates for acquired hypothyroidism and thyrotoxicosis, analysing all certified causes of death (termed 'mentions') and not just the underlying cause.

DESIGN

Analysis of death registration data.

METHODS

Analysis of data for the Oxford region (mentions available from 1979) and English national data (mentions available from 1995). The data were grouped in periods defined by different national rules for selecting the underlying cause of death (1979-83, 1984-92, 1993-2000 and 2001-10) and were also analysed as single calendar years.

RESULTS

Mentions mortality for acquired hypothyroidism in the Oxford region declined significantly from 1979 to 2010: the average annual percentage change (AAPC) was -2.6% (95% confidence intervals -3.5, -1.8). Most of the decrease occurred during the 1980s. The AAPC in rates for later years in England (1995-2010) was non-significant at 0.2% (-0.7, 1.0). Mortality rates for thyrotoxicosis decreased significantly: the AAPC was -2.8% (-4.1, -1.5) in the Oxford region and -3.8% (-4.7, -3.0) in England. In England, between 2001 and 2010, hypothyroidism or thyrotoxicosis was coded as the underlying cause of death on, respectively, 17 and 24% of death certificates that included them.

CONCLUSION

Mortality rates for hypothyroidism and thyrotoxicosis have fallen substantially. The fall is probably wholly or mainly a result of improved care.

Excess mortality in patients diagnosed with hypothyroidism: a nationwide cohort study of singletons and twins

BACKGROUND

Although hypothyroidism is associated with increased morbidity, an association with increased mortality is still debated. Our objective was to investigate, at a nationwide level, whether a diagnosis of hypothyroidism influences mortality.

METHODS

In an observational cohort study from January 1, 1978 until December 31, 2008 using record-linkage data from nationwide Danish health registers, 3587 singletons and 682 twins diagnosed with hypothyroidism were identified. Hypothyroid individuals were matched 1:4 with nonhypothyroid controls with respect to age and gender and followed over a mean period of 5.6 years (range 0-30 years). The hazard ratio (HR) for mortality was calculated using Cox regression analyses. Comorbidity was evaluated using the Charlson score (CS).

RESULTS

In singletons with hypothyroidism, the mortality risk was increased (HR 1.52; 95% confidence interval [CI]: 1.41-1.65). Although the effect attenuated, hypothyroidism remained associated with increased mortality when evaluating subjects with a CS = 0 (HR 1.23; 95% CI: 1.05-1.44). In twin pairs discordant for hypothyroidism, the hypothyroid twin had excess mortality compared with the corresponding euthyroid cotwin (HR 1.40; 95% CI 0.95-2.05). However, after stratifying for zygosity, hypothyroidism was associated with excess mortality in dizygotic twin pairs (HR 1.61; 95% CI 1.00-2.58), whereas the association attenuated in monozygotic pairs (HR 1.06; 95% CI 0.55-2.05).

CONCLUSIONS

Hypothyroidism is associated with an excess mortality of around 50%, which to some degree is explained by comorbidity. In addition, the finding of an association between hypothyroidism and mortality within disease discordant dizygotic but not monozygotic twin pairs indicates that the association between hypothyroidism and mortality is also influenced by genetic confounding.

A review of the evidence for and against increased mortality in hypothyroidism

The lifetime risk of overt hypothyroidism is around 5%, and this disease is usually preceded by subclinical hypothyroidism, which has an even higher prevalence (estimated to be up to 9%). Hypothyroidism has been linked with cardiac dysfunction, atherosclerosis, hypertension and coagulopathy. Intuitively, this increased morbidity is expected to shorten patients' lifespan, but definitive data are lacking on whether either of these hypothyroid states (particularly overt hypothyroidism) increase mortality. Study findings are inconsistent and, overall, the pooled data do not demonstrate increased mortality in patients with either subclinical or overt hypothyroidism. However, none of the available studies was adequately designed to answer this question. This Review discusses major shortcomings in those studies, such as population dissimilarities, hypothyroid state classification and misclassification, the inclusion of nonthyroidal illness, drug interference from concurrent therapies, serious comorbidities (for example, cardiovascular disease), differences in duration of follow-up and the number of levothyroxine-treated individuals. Taken together, the data exhibit little evidence of systematic bias and no strong scientific proof of increased mortality related to either subclinical or overt hypothyroidism. Future studies, however, should take the above-mentioned shortcomings and potential genetic confounding into consideration.

Endogenous subclinical thyroid disorders, physical and cognitive function, depression, and mortality in older individuals

OBJECTIVE

To what extent endogenous subclinical thyroid disorders contribute to impaired physical and cognitive function, depression, and mortality in older individuals remains a matter of debate.

DESIGN

A population-based, prospective cohort of the Longitudinal Aging Study Amsterdam.

METHODS

TSH and, if necessary, thyroxine and triiodothyronine levels were measured in individuals aged 65 years or older. Participants were classified according to clinical categories of thyroid function. Participants with overt thyroid disease or use of thyroid medication were excluded, leaving 1219 participants for analyses. Outcome measures were physical and cognitive function, depressive symptoms (cross-sectional), and mortality (longitudinal)

RESULTS

Sixty-four (5.3%) individuals had subclinical hypothyroidism and 34 (2.8%) individuals had subclinical hyperthyroidism. Compared with euthyroidism (n=1121), subclinical hypo-, and hyper-thyroidism were not significantly associated with impairment of physical or cognitive function, or depression. On the contrary, participants with subclinical hypothyroidism did less often report more than one activity limitation (odds ratio 0.44, 95% confidence interval (CI) 0.22-0.86). After a median follow-up of 10.7 years, 601 participants were deceased. Subclinical hypo- and hyper-thyroidism were not associated with increased overall mortality risk (hazard ratio 0.89, 95% CI 0.59-1.35 and 0.69, 95% CI 0.40-1.20 respectively).

CONCLUSIONS

This study does not support disadvantageous effects of subclinical thyroid disorders on physical or cognitive function, depression, or mortality in an older population.

Thyroid hormone, amiodarone therapy, and prognosis in left ventricular systolic dysfunction

BACKGROUND

Amiodarone protects patients with left ventricular systolic dysfunction (LVSD) against serious arrhythmias, but it also has numerous side effects on non-cardiac organs, such as the thyroid. Indeed, amiodarone may inhibit the peripheral conversion of T₄ into T₃. Pathologically reduced serum levels of T₃ - the so-called "low T₃ syndrome" (LOWT3) - increase mortality in patients with LVSD and not on amiodarone.

AIM

The aim of the study was to examine the relationship between thyroid hormone status, amiodarone therapy, and outcome in a population with LVSD. MATERIAL/ SUBJECTS AND METHODS: A total of 2344 patients with LVSD and free of overt hyper- and hypothyroidism were enrolled. The population was divided into 4 groups: group 1 (LOWT3 and amiodarone therapy, no.=126), group 2 (isolated amiodarone therapy, no.=74), group 3 (isolated LOWT3, no.=682), group 4 (controls, no.=1462).

RESULTS

Kaplan-Meier curves showed, after a mean follow-up of 31 months, increased total and cardiac mortality in groups 1 (30% and 20%, respectively), 2 (23%, 11%), and 3 (22%, 12%) compared to group 4 (total mortality log-rank 82.8, p<0.0001; cardiac mortality log-rank 63.1, p<0.0001). At Cox analysis, adjusted for several clinical variables, survival was reduced in groups 1 and 3 compared to group 4. Group 2 had a similar mortality to group 4, although the number of patients was too limited to accurately assess the effect of amiodarone on long-term prognosis.

CONCLUSIONS

LOWT3 exerts an adverse impact on prognosis in LVSD, which is not influenced by concomitant amiodarone therapy.

The incidence of ischemic heart disease and mortality in people with subclinical hypothyroidism: reanalysis of the Whickham Survey cohort

CONTEXT

The Whickham Survey evaluated vascular events over 20 yr in community-dwelling subjects stratified by thyroid function and thyroid autoantibody status. No association between ischemic heart disease (IHD) and a composite autoimmune thyroid disease group, comprising individuals with subclinical hypothyroidism (SCH), with positive thyroid antibodies or those using levothyroxine, was found. This result appears to be at odds with the findings of other cohort studies.

OBJECTIVE

The objective of the study was to evaluate incident IHD and mortality in participants in relation to their thyroid status. OUTCOMES, DESIGN, AND PARTICIPANTS: Data were reanalyzed assessing incident IHD events and mortality during 20 yr of follow-up in individuals with endogenous SCH (n = 97; TSH 6.0-15 mIU/liter) vs. the euthyroid group (n = 2279), who were IHD free at baseline.

RESULTS

Incident IHD was significantly higher in the SCH group [adjusted hazard ratio 1.76 (95% confidence interval 1.15-2.71); P = 0.01]. IHD mortality was also increased in the SCH group [hazard ratio of 1.79 (1.02-3.56); P = 0.05]. These findings lost their significance when subsequent treatment with levothyroxine was excluded from the regression model. There was no difference in all-cause mortality between the groups.

CONCLUSION

In the Whickham Survey, there is an association between incident IHD events and IHD-related mortality with SCH over the 20 yr of follow-up. Furthermore, subsequent treatment of SCH with levothyroxine appears to attenuate IHD-related morbidity and mortality, and this may explain why some other longitudinal studies of SCH have not shown such an association; properly designed controlled trials of treatment of SCH are required to answer this question definitively.

Subclinical thyroid dysfunction and mortality: an estimate of relative and absolute excess all-cause mortality based on time-to-event data from cohort studies

OBJECTIVES

To what extent persons with subclinical hyper- or hypothyroidism are more (or less) likely to die than euthyroid control subjects remains a matter of controversy.

METHODS

We searched electronic reference databases up to July 31, 2007. Three reviewers independently assessed eligibility. Cohort studies published in full that reported data on the hazard ratio (HR) for mortality from all causes in persons with subclinical thyroid dysfunction versus euthyroid controls were included.

RESULTS

Based on seven cohorts including 290 participants with subclinical hyperthyroidism, random-effects models estimated that the pooled HR for all-cause mortality was 1.41 (95% confidence interval (CI), 1.12-1.79; P=0.004). Using the pooled HR and standard life-table methods applied to a US reference population, we estimated that a white US woman, when diagnosed with subclinical hyperthyroidism at age of 70, has an excess mortality of 1.5, 4.0, and 8.7% at 2, 5, and 10 years respectively after diagnosis. Likewise, a white US man has an excess mortality of 2.3, 5.7, and 10.7%. For the nine cohorts including 1580 participants with subclinical hypothyroidism, observed heterogeneity (Q test P=0.006; I(2)=63%) disappeared after pooling cohorts in predefined subgroups according to the presence or absence of a comorbid condition. In doing so, the pooled HR for all-cause mortality was 1.03 (95% CI, 0.78-1.35; P=0.83) in cohorts from the community and 1.76 (95% CI, 1.36-2.30; P<0.001) in cohorts of participants with comorbidities (P=0.014 for heterogeneity among study groups).

CONCLUSIONS

Individuals with subclinical hyperthyroidism demonstrate a 41% increase in relative mortality from all causes versus euthyroid control subjects. Mathematical modeling suggests that absolute excess mortality after diagnosis might depend on age, with an increase beyond the age of 60, especially in aging men. For patients with subclinical hypothyroidism, the relative risk of all-cause mortality is increased only in patients with comorbid conditions.

Low triiodothyronine: a strong predictor of outcome in acute stroke patients

BACKGROUND

Low triiodothyronine (T3) has been associated with increased short-term mortality in intensive care unit patients and long-term mortality in patients with heart disease. The objective of this study was to investigate possible associations of thyroid hormone status with clinical outcome in patients admitted for acute stroke.

MATERIALS AND METHODS

A total of 737 consecutive patients with acute first ever stroke who presented within 24 h from symptoms' onset were studied. Total T3, thyroxin (T4) and thyroid-stimulating hormone (TSH) levels were assessed in the morning following admission. Cases with T3 values < or = 78 ng dL(-1) (1.2 nmol L(-1)) (median) were characterized as 'low T3'. Cases with T4 values < or = 4.66 microg dL(-1) (60 nmol L(-1)) were characterized as 'low T4'. Basic and clinical characteristics, stroke risk factors, and brain imaging were evaluated. Neurological impairment was assessed using the Scandinavian Stroke Scale.

RESULTS

Four hundred and seventeen (56%) patients had T3 values < or = 78 ng dL(-1) and 320 had normal T3 values. The 1-year mortality was 27.34% for low T3 and 19.37% for normal T3 cases (P = 0.006). A smaller percentage of patients with low T3 values were independent at 1 year compared to those with normal T3 values [54.2% vs. 68.7%, chi(2) = 12.09, P < 0.001, odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.37-0.76]. Cox regression analysis revealed that increased age, haemorrhagic stroke, low Scandinavian Stroke Scale score, increased glucose and low T3 values (hazards ratio 0.69, CI = 0.48-0.98, P = 0.041) were significant predictors of 1-year mortality.

CONCLUSIONS

A high proportion of patients with acute stroke were found soon after the event with low T3 values. The low-T3 syndrome is an independent predictor of early and late survival in patients with acute stroke, and predicts handicap at 1 year.

Long-term outcomes after allogeneic stem cell transplantation for children with hematological malignancies

We analyzed long-term outcomes and psycho-social aspects in 112 children with malignancies surviving 1 year after hematopoietic stem cell transplantation. At 10 years, overall survival was 75+/-5%, TRM 18+/-4% and relapse 14+/-3%; 10-year cumulative incidence of infections was 31+/-4%, cataract 44+/-4%, pulmonary dysfunction 20+/-4%, bone and joint complications 29+/-5%, hypothyroidism 36+/-4%, cardiac complications 11+/-3% and secondary malignancies 7+/-3%. Total body irradiation (TBI) was the most significant risk factor associated with cataract, pulmonary impairment, osteoarticular complications and hypothyroidism. Chronic graft-versus-host disease was associated with higher incidence of pulmonary dysfunction. The number of complications per patient increased with time. Half of the patients had psychological disturbance, 13 signs of depression and 16 a history of eating behavior disorders; 54% of patients with one or more long-term complications had psychological problems. Sixty-nine patients had learning difficulties and 36 achieved normal scholarship. With increased follow-up, development of late effects and of psycho-social disturbance are of major concern. While the use of single-dose TBI has now been abandoned, other risk factors are still of concern in the early 2000s.

Subclinical hypothyroidism is linked to micro-inflammation and predicts death in continuous ambulatory peritoneal dialysis

BACKGROUND

Low T3 is a frequent alteration in patients with ESRD. This derangement has been recently linked to inflammation in haemodialysis patients. Whether this association holds true in peritoneal dialysis patients has not been studied.

METHODS

We investigated the relationship between low-grade inflammation [IL-6, C-reactive protein (CRP) and serum albumin levels] and free tri-iodothyronine (fT3) in a cohort of 41 CAPD patients (mean age, 66 years; M, 26; F, 15) without heart failure and inter-current illnesses.

RESULTS

CAPD patients had lower fT3 levels (2.7 +/- 0.8 pg/ml) than healthy subjects (3.7 +/- 1.0 pg/ml, P < 0.001) of similar age. Free T3 levels were directly related to those of serum albumin (r = 0.52, P = 0.001) and inversely to IL-6 (r = -0.30, P = 0.05) and CRP (r = -0.54, P < 0.001). Age (r = -0.61, P < 0.001), haemoglobin levels (r = 0.32, P = 0.05) and diastolic blood pressure (r = 0.50, P = 0.001) were also related to fT3. In multiple regression models adjusting for all variables related to fT3, CRP and albumin were retained as independent correlates of fT3. During the follow-up (2.8 +/- 1.7 years) 27 patients died. Plasma fT3 levels were lower in patients who died (2.5 +/- 0.8 pg/ml) compared with survivors (3.3 +/- 0.5 pg/ml P = 0.001). In Cox analyses, fT3 was a significant predictor of mortality independent of the main traditional as well as non-traditional risk factors.

CONCLUSIONS

The relationship between fT3, CRP and serum albumin suggests that inflammation-malnutrition might be involved in the low T3 syndrome in CAPD patients. Thyroid dysfunction might be implicated in the pathogenic pathway which links micro-inflammation to survival in PD patients.

Low triiodothyronine and survival in end-stage renal disease

Plasma triiodothyronine (fT3) is a strong predictor of adverse clinical outcomes in various clinical conditions. Since fT3 in patients with end-stage renal diseases (ESRD) is frequently reduced and is associated with inflammation and cardiovascular damage, we prospectively tested the hypothesis that it predicts death in a cohort of 200 hemodialysis patients. Plasma fT3 was lower in ESRD patients (P<0.001) than in healthy subjects and in clinically euthyroid patients with normal renal function. During the follow-up 102 patients died. Patients who died had significantly lower plasma fT3 than those who survived (P<0.001) and in a Kaplan-Meyer analysis plasma fT3 was associated with death (P<0.001). On multivariate Cox's regression analyses, adjusting for a series of traditional and emerging risk factors including inflammation markers, patients with relatively higher plasma fT3 (hazard ratio (HR) (1 pg/ml increase in fT3)) had a 50% reduction in the risk of death (HR=0.50, 95% CI: 0.35-0.72) as compared to those having relatively lower fT3 levels. Of note, plasma fT3 captured most of the predictive power of interleukin-6 (IL-6) because this latter variable emerged as a significant predictor of death only in a model excluding fT3. Low fT3 is an independent predictor of death in hemodialysis patients. These data lend support to the hypothesis that thyroid dysfunction is implicated in the high risk of the ESRD population.

Mortality and vascular outcomes in patients treated for thyroid dysfunction

CONTEXT

There are limited studies describing mortality and morbidity in patients treated for hyperthyroidism, and no data exist for people with treated hypothyroidism.

OBJECTIVE

The objective of the study was to describe all-cause mortality and vascular mortality and morbidity in patients after treatment for hyperthyroidism and hypothyroidism.

DESIGN

This was a population-based cohort study from 1994 to 2001.

SETTING

The study was conducted in Tayside, Scotland.

PATIENTS

All patients were treated for thyroid dysfunction.

INTERVENTION(S)

Event rates among patients with thyroid dysfunction were compared with rates in the general population. We measured standardized mortality ratio and standardized incidence ratio (SIR).

MAIN OUTCOME MEASURE(S)

The primary outcome was all-cause mortality. The secondary outcome was serious vascular event, the composite end point of nonfatal myocardial infarction, nonfatal stroke, or vascular death.

RESULTS

There were 15,889 primary hypothyroid and 3,888 hyperthyroid patients. There were 3,116,719 patient-years of follow-up in 524,152 subjects in the general population. No increase was found in all-cause mortality or serious vascular events in patients with treated hypothyroidism or hyperthyroidism. Nonfatal ischemic heart disease [SIR 1.23, 95% confidence interval (CI) 1.10-1.36] and dysrhythmias (SIR 1.32, 95% CI 1.11-1.57) were increased in treated hypothyroidism when adjusted for age, sex, diabetic status, and previous vascular disease. In treated stabilized hyperthyroidism, only the risk of dysrhythmias was increased (SIR 2.71, 95% CI 1.63-4.24). Risk of heart failure or cerebrovascular disease was not increased in either patient group.

CONCLUSIONS

We found no increase in all-cause mortality in subjects with treated thyroid disease. However, there was increased risk of cardiovascular morbidity in patients with treated primary hypothyroidism and dysrhythmias in treated hyperthyroidism.