Thyroid dysfunction and anemia in a large population-based study.

OBJECTIVE AND BACKGROUND Anemia and thyroid dysfunction are common and often co-occur. Current guidelines recommend the assessment of thyroid function in the work-up of anemia, although evidence on this association is scarce. PATIENTS AND METHODS In the "European Prospective Investigation of Cancer" (EPIC)-Norfolk population-based cohort, we aimed to examine the prevalence and type of anemia (defined as hemoglobin <13 g/dl for men and <12 g/dl for women) according to different thyroid function groups. RESULTS The mean age of the 8791 participants was 59.4 (SD 9.1) years and 55.2% were women. Thyroid dysfunction was present in 437 (5.0%) and anemia in 517 (5.9%) participants. After excluding 121 participants with three most common causes of anemia (chronic kidney disease, inflammation, iron deficiency), anemia was found in 4.7% of euthyroid participants. Compared with the euthyroid group, the prevalence of anemia was significantly higher in overt hyperthyroidism (14.6%, P < .01), higher with borderline significance in overt hypothyroidism (7.7%, P = .05) and not increased in subclinical thyroid dysfunction (5.0% in subclinical hypothyroidism, 3.3% in subclinical hyperthyroidism). Anemia associated with thyroid dysfunction was mainly normocytic (94.0%), and rarely macrocytic (6.0%). CONCLUSION The prevalence of anemia was higher in overt hyperthyroidism, but not increased in subclinical thyroid dysfunction. Systematic measurement of thyroid-stimulating hormone in anemic patients is likely to be useful only after excluding common causes of anemia.

Subclinical Thyroid Dysfunction and Frailty Among Older Men

CONTEXT Both subclinical thyroid dysfunction and frailty are common among older individuals, but data on the relationship between these 2 conditions are conflicting. OBJECTIVE The purpose of this study was to assess the cross-sectional and prospective associations between subclinical thyroid dysfunction and frailty and the 5 frailty subdomains (sarcopenia, weakness, slowness, exhaustion, and low activity). SETTING AND DESIGN The Osteoporotic Fractures in Men Study is a prospective cohort study. PARTICIPANTS Men older than 65 years (n = 1455) were classified into 3 groups of thyroid status: subclinical hyperthyroidism (n = 26, 1.8%), subclinical hypothyroidism (n = 102, 7.0%), and euthyroidism (n = 1327, 91.2%). MAIN OUTCOME MEASURES Frailty was defined using a slightly modified Cardiovascular Health Study Index: men with 3 or more criteria were considered frail, men with 1 to 2 criteria were considered intermediately frail, and men with no criteria were considered robust. We assessed the cross-sectional relationship between baseline thyroid function and the 3 categories of frailty status (robust/intermediate/frail) as well as the prospective association between baseline thyroid function and subsequent frailty status and mortality after a 5-year follow-up. RESULTS At baseline, compared with euthyroid participants, men with subclinical hyperthyroidism had an increased likelihood of greater frailty status (adjusted odds ratio, 2.48; 95% confidence interval, 1.15-5.34), particularly among men aged <74 years at baseline (odds ratio for frailty, 3.63; 95% confidence interval, 1.21-10.88). After 5 years of follow-up, baseline subclinical hypothyroidism and hyperthyroidism were not consistently associated with overall frailty status or frailty components. CONCLUSION Among community-dwelling older men, subclinical hyperthyroidism, but not subclinical hypothyroidism, is associated with increased odds of prevalent but not incident frailty.

Association between thyroid dysfunction and venous thromboembolism in the elderly: a prospective cohort study.

BACKGROUND Venous thromboembolism (VTE) and subclinical thyroid dysfunction (SCTD) are both common in elderly patients. SCTD has been related to a hypercoagulable state and increased thromboembolic risk. However, prospective data on the relationship between SCTD and VTE are lacking. OBJECTIVES To investigate the relationship between SCTD and recurrent VTE (rVTE), all-cause mortality, and thrombophilic biomarkers. PATIENTS Elderly participants with VTE. METHODS In a prospective multicenter cohort, thyroid hormones and thrombophilic biomarkers were measured 1 year after acute VTE, as both may be influenced by acute thrombosis. We defined subclinical hypothyroidism (SHypo) as elevated thyroid stimulating hormone levels (TSH=4.50-19.99 mIU/l), and subclinical hyperthyroidism (SHyper) as TSH<0.45, both with normal free thyroxine levels. Outcomes were incidence of rVTE and overall mortality during follow-up starting after the 1-year blood sampling. RESULTS Of 561 participants (58% with anticoagulation), 6% had SHypo and 5% SHyper. After 20.8 months of mean follow-up, 9% developed rVTE and 10% died. rVTE incidence rate was 7.2 (95% confidence interval:2.7-19.2) per 100 patient-years in SHypo, 0.0 (0.0-7.6) in SHyper and 5.9 (4.4-7.8) in euthyroid participants. In multivariate analyses, the sub-hazard ratio [SHR] for rVTE was 0.00 (0.00-0.58) in SHyper and 1.50 (0.52-4.34) in SHypo compared to euthyroids, without increased thrombophilic biomarkers. SHyper (HR 0.80,0.23-2.81) and SHypo (HR 0.99,0.30-3.29) were not associated with mortality. CONCLUSION In elderly patients, SHyper may be associated with lower rVTE risks. SHypo showed a non-statistically significant pattern of an association with rVTE, without increased mortality or differences in thrombophilic biomarkers. This article is protected by copyright. All rights reserved.

Thyroid disruption in zebrafish (Danio rerio) larvae: Different molecular response patterns lead to impaired eye development and visual functions

The vertebrate thyroid system is important for multiple developmental processes, including eye development. Thus, its environmentally induced disruption may impact important fitness-related parameters like visual capacities and behaviour. The present study investigated the relation between molecular effects of thyroid disruption and morphological and physiological changes of eye development in zebrafish (Danio rerio). Two test compounds representing different molecular modes of thyroid disruption were used: propylthiouracil (PTU), which is an enzyme-inhibitor of thyroid hormone synthesis, and tetrabromobisphenol A (TBBPA), which interacts with the thyroid hormone receptors. Both chemicals significantly altered transcript levels of thyroid system-related genes (TRα, TRβ, TPO, TSH, DIO1, DIO2 and DIO3) in a compound-specific way. Despite these different molecular response patterns, both treatments resulted in similar pathological alterations of the eyes such as reduced size, RPE cell diameter and pigmentation, which were concentration-dependent. The morphological changes translated into impaired visual performance of the larvae: the optokinetic response was significantly and concentration-dependently decreased in both treatments, together with a significant increase of light preference of PTU-treated larvae. In addition, swimming activity was impacted. This study provides first evidence that different modes of molecular action of the thyroid disruptors can be associated with uniform apical responses. Furthermore, this study is the first to show that pathological eye development, as it can be induced by exposure to thyroid disruptors, indeed translates into impaired visual capacities of zebrafish early life stages.

Comparison of multiple comparison methods for identifying differential gene expression in simulated and real papillary thyroid cancer microarray data

The difficulty of detecting differential gene expression in microarray data has existed for many years. Several correction procedures try to avoid the family-wise error rate in multiple comparison process, including the Bonferroni and Sidak single-step p-value adjustments, Holm's step-down correction method, and Benjamini and Hochberg's false discovery rate (FDR) correction procedure. Each multiple comparison technique has its advantages and weaknesses. We studied each multiple comparison method through numerical studies (simulations) and applied the methods to the real exploratory DNA microarray data, which detect of molecular signatures in papillary thyroid cancer (PTC) patients. According to our results of simulation studies, Benjamini and Hochberg step-up FDR controlling procedure is the best process among these multiple comparison methods and we discovered 1277 potential biomarkers among 54675 probe sets after applying the Benjamini and Hochberg's method to PTC microarray data.^

Socioeconomic disparities in thyroid cancer incidence within the Surveillance, Epidemiology, and End Results (SEER) registry, 1980--2008

Background. In the past two decades, the incidence of thyroid cancer in the United States (US) has been increasing. There has been debate on whether the increase is real or an artifact of improved diagnostic scrutiny. Methods. We linked SEER9 database with 2000 US Census to obtain county-level SES (Socioeconomic Status) and compared thyroid cancer incidence trends between high and low SES counties. Joinpoint analysis was used to assess the thyroid cancer incidence trends. Annual Percentage Changes (APCs) were calculated to evaluate incidence trends. Results . The thyroid cancer incidence in high SES counties increased moderately (APC1=+2.5*, *P<0.05) before late 1990s and dramatically increased (APC2=+6.3*) after late 1990s, whereas incidence in low SES counties increased moderately (APC=+3.5*) during the entire time period (1980–2008). For smaller tumors (≤4cm), the APCs in high and low SES counties are similar to each other before late 1990s, but the incidence in high SES counties increased dramatically after late 1990s while that in low SES counties continued at a moderate increase. For large tumors (>4cm), the incidence trends in high SES counties are similar to those of low SES counties, which had a steady moderate increase. Conclusion. Our findings indicate that enhanced detection likely contributed to the increased thyroid cancer incidence in the past decades but cannot fully explain the increase, suggesting that a true increase also exists. Efforts should be made on identifying the cause of this observed increased incidence as well as more refined/selected screening and prevention measures.^

THE IMPACT OF FAMILY HISTORY ON MEDULLARY THYROID CANCER IN MEN2A PATIENTS

The American Thyroid Association recently classified all MEN2A-associated codons into increasing risk levels A-C and stated that some patients may delay prophylactic thyroidectomy if certain criteria are met. One criterion is a less aggressive family history of MTC but whether families with the same mutated codon have variable MTC aggressiveness is not well described. We developed several novel measures of MTC aggressiveness and compared families with the same mutated codon to determine if there is significant inter-familial variability. Pedigrees of families with MEN2A were reviewed for codon mutated and proportion of RET mutation carriers with MTC. Individuals with MTC were classified as having local or distant MTC and whether they had progressive MTC. MTC status and age were assessed at diagnosis and most advanced MTC stage. For those without MTC, age was recorded at prophylactic thyroidectomy or last follow-up if the patient did not have a thyroidectomy. For each pedigree, the mean age of members without MTC, with MTC, and the proportion of RET mutation carriers with local or distant and progressive MTC were calculated. We assessed differences in these variables using ANOVA and the Fisher’s exact test. Sufficient data for analysis were available for families with mutated codons 609 (92 patients from 13 families), 618 (41 patients from 7 families), and 634 (152 patients from 13 families). The only significant differences found were the mean age of patients without MTC between families with codon 609 and 618 mutations even after accounting for prophylactic thyroidectomy (p=0.006 and 0.001, respectively), and in the mean age of MTC diagnosis between families with codon 618 and 634 mutations even after accounting for symptomatic presentation (p=0.023 and 0.014, respectively). However, these differences may be explained by generational differences in ascertainment of RET carriers and the availability of genetic testing when the proband initially presented.

(Table 2) Radiolaria species in nodule samples from the Clarion-Clipperton province, Pacific Ocean

Radiolaria were studied in 19 manganese nodules raised from the bottom. The nodules occurred mainly on the surface of thin Quaternary sediments covering Tertiary deposits of various ages (Middle Eocene to Early Miocene). Radiolaria in nodule cores and in inner and surface layers were studied. We found 85 radiolaria species and groups of species. Usually 1-4 to 6-19 radiolaria species were detected in each of the samples. Species belonging to Middle Eocene, Late Miocene to Early Oligocene, and Oligocene to Early Miocene were found. Rare Neogene species were revealed only in fractured surface layers. Age of the nodules is mainly Oligocene. Seismic waves cause sediment vibration, loosening disintegration, and removal of suspension by bottom currents. The vibration effect causes ancient nodules to float up to the surface of Quaternary sediment. This hypothesis suggests the reason for characteristics of the Clarion-Clipperton zone: regional stratigraphic hiatus, accumulation of residual fields of nodules, and the ''floating up'' of nodules to the surface of the Quaternary sediments.

(Table S2, page 46-47) Manganese nodule sampling station data

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