Alcohol consumption is associated with reduced prevalence of goitre and solitary thyroid nodules

Cancer Risk According to Alcohol Consumption Trajectories: A Population-based Cohort Study of 2.8 Million Korean Men

BACKGROUND

Alcohol drinking behaviors change temporally and can lead to changes in related cancer risks; previous studies have been unable to identify the association between the two using a single-measurement approach. Thus, this study aimed to investigate the association of drinking trajectories with the cancer risk in Korean men.

METHODS

A trajectory analysis using group-based trajectory modeling was performed on 2,839,332 men using data on alcohol drinking levels collected thrice during the Korean National Health Insurance Service's general health screening program conducted between 2002 and 2007. Cox proportional hazards regression was performed to evaluate the associations between drinking trajectories and cancer incidence, after adjustments for age, income, body mass index, smoking status, physical activity, family history of cancer, and comorbidities.

RESULTS

During 10.5 years of follow-up, 189,617 cancer cases were recorded. Six trajectories were determined: non-drinking, light, moderate, decreasing-heavy, increasing-heavy, and steady-heavy. Light-to-heavy alcohol consumption increased the risk for all cancers combined in a dose-dependent manner (adjusted hazard ratio [aHR] 1.03; 95% confidence interval [CI], 1.02-1.05 for light drinking, aHR 1.06; 95% CI 1.05-1.08 for moderate drinking, aHR 1.19; 95% CI, 1.16-1.22 for decreasing-heavy drinking, aHR 1.23; 95% CI, 1.20-1.26 for increasing-heavy drinking, and aHR 1.33; 95% CI, 1.29-1.38 for steady-heavy drinking [P-trend <0.001]). Light-to-heavy alcohol consumption was linked to lip, oral cavity, pharyngeal, esophageal, colorectal, laryngeal, stomach, and gallbladder and biliary tract cancer risks, while heavy alcohol consumption was associated with hepatic, pancreatic, and lung cancer risks. An inverse association was observed for thyroid cancer. The cancer risks were lower for decreasing-heavy drinkers, compared to steady-heavy drinkers.

CONCLUSION

No safe drinking limits were identified for cancer risks; reduction in heavy intake had protective effects.

Thyroid hormone action and liver disease, a complex interplay

Thyroid hormone action is involved in virtually all physiological processes. It is well known that the liver and thyroid are intimately linked, with thyroid hormone playing important roles in de novo lipogenesis, beta-oxidation (fatty acid oxidation), cholesterol metabolism, and carbohydrate metabolism. Clinical and mechanistic research studies have shown that thyroid hormone can be involved in chronic liver diseases, including alcohol-associated or NAFLD and HCC. Thyroid hormone action and synthetic thyroid hormone analogs can exert beneficial actions in terms of lowering lipids, preventing chronic liver disease and as liver anticancer agents. More recently, preclinical and clinical studies have indicated that some analogs of thyroid hormone could also play a role in the treatment of liver disease. These synthetic molecules, thyromimetics, can modulate lipid metabolism, particularly in NAFLD/NASH. In this review, we first summarize the thyroid hormone signaling axis in the context of liver biology, then we describe the changes in thyroid hormone signaling in liver disease and how liver diseases affect the thyroid hormone homeostasis, and finally we discuss the use of thyroid hormone-analog for the treatment of liver disease.

Association Between Genetic Risk, Adherence to Healthy Lifestyle Behavior, and Thyroid Cancer Risk

Importance

Genetic and lifestyle factors are related to thyroid cancer (TC). Whether a healthy lifestyle is associated with TC and could attenuate the influence of genetic variants in TC remains equivocal.

Objectives

To examine the associations between genetics and healthy lifestyle with incident TC and whether adherence to a healthy lifestyle modifies the association between genetic variants and TC.

Design, Setting, and Participants

A prospective cohort study using UK Biobank data recruited 502 505 participants aged 40 to 69 years between March 13, 2006, and October 1, 2010. A total of 307 803 participants of European descent were recruited at baseline, and 264 956 participants were available for the present study. Data analysis was conducted from November 1, 2021, to April 22, 2022.

Exposures

Lifestyle behaviors were determined by diet index, physical activity, weight, smoking, and alcohol consumption. Lifestyle was categorized as unfavorable (scores 0-1), intermediate (score 2), and favorable (scores 3-5). The polygenic risk score (PRS) was derived from a meta-genome-wide association study using 3 cohorts and categorized as low, intermediate, and high.

Main Outcomes and Measures

Thyroid cancer was defined using the International Classification of Diseases, Ninth Revision (code 193), International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (code C73), and self-report (code 1065).

Results

Of 264 956 participants, 137 665 were women (52%). The median age was 57 (IQR, 49-62) years. During a median follow-up of 11.1 (IQR, 10.33-11.75) years (2 885 046 person-years), 423 incident TCs were ascertained (14.66 per 100 000 person-years). Higher PRSs were associated with TC (hazard ratio [HR], 2.25; 95% CI, 1.91-2.64; P = 8.65 × 10-23). An unfavorable lifestyle was also associated with a higher risk of TC (HR, 1.93; 95% CI, 1.50-2.49; P < .001). When stratified by PRS, unfavorable lifestyle was associated with TC in the higher PRS group (favorable vs unfavorable HR, 0.52; 95% CI, 0.37-0.73; P < .001). Furthermore, participants with both a high PRS and unfavorable lifestyle had the highest risk of TC (HR, 4.89; 95% CI, 3.03-7.91; P < .001).

Conclusions and Relevance

In this prospective cohort study, genetic and lifestyle factors were independently associated with incident TC, which suggests that a healthier lifestyle may attenuate the deleterious influence of genetics on the risk of TC in individuals of European descent.

Illustration of Gut-Thyroid Axis in Alcohol Use Disorder: Interplay of Gut Dysfunction, Pro-Inflammatory Responses, and Thyroid Function

(1) Background: Heavy and chronic alcohol drinking leads to altered gut dysfunction, coupled with a pro-inflammatory state. Thyroid-associated hormones and proteins may be dysregulated by heavy and chronic alcohol intake; however, the mechanism for altered gut-derived changes in thyroid function has not been studied thus far. This study investigates the role of alcohol-induced gut dysfunction and pro-inflammatory cytokine profile in the thyroid function of patients with alcohol use disorder (AUD). (2) Methods: Male and female AUD patients (n = 44) were divided into Gr.1, patients with normal thyroid-stimulating hormone (TSH) levels (n = 28, 0.8 ≤ TSH ≤ 3 mIU/L); and Gr.2, patients with clinically elevated TSH levels (n = 16, TSH > 3 mIU/L). Demographics, drinking measures, comprehensive metabolic panels, and candidate thyroid markers (TSH, circulating triiodothyronine (T3), and free thyroxine (fT4)) were analyzed. Gut-dysfunction-associated markers (lipopolysaccharide (LPS), LPS-binding protein (LBP), and soluble LPS-induced pathogen-associated protein (sCD14)), and candidate pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-8, MCP-1, PAI-1) were also evaluated. (3) Results: Patients in both groups presented with a borderline overweight BMI category. Gr.2 reported numerically higher indices of chronic and heavy drinking patterns than Gr.1. The fT4 levels were elevated, while T3 was within normal limits in both groups. The gut dysfunction markers LBP and sCD14 were numerically elevated in Gr.2 vs. Gr.1, suggesting subtle ongoing changes. Candidate pro-inflammatory cytokines were significantly elevated in Gr.2, including IL-1 β, MCP-1, and PAI-1. Gr.2 showed a strong and statistically significant effect on the gut–immune–thyroid response (r = 0.896, 36 p = 0.002) on TSH levels in a multivariate regression model with LBP, sCD14, and PAI-1 levels as upstream variables in the gut–thyroid pathway. In addition, AUROC analysis demonstrated that many of the cytokines strongly predicted TSH in Gr.2, including IL-6 (area = 0.774, 39 p < 0.001) and TNF-α (area = 0.708, p = 0.017), among others. This was not observed in Gr.1. Gr.2 demonstrated elevated fT4, as well as TSH, which suggests that there was subclinical thyroiditis with underlying CNS dysfunction and a lack of a negative feedback loop. (4) Conclusions: These findings reveal the toxic effects of heavy and chronic drinking that play a pathological role in thyroid gland dysregulation by employing the gut–brain axis. These results also emphasize potential directions to carefully evaluate thyroid dysregulation in the overall medical management of AUD.

The Prevalence and Risk Factors Associated with Iodine Deficiency in Canadian Adults

Iodine is a trace micronutrient that is critical for normal thyroid function and human health. Inadequate dietary intake is associated with cognitive impairment, infertility, growth retardation and iodine deficiency disorders in affected populations. Herein, we examined the prevalence of iodine deficiency in adults (median age of 61 years) based on the analysis of 24 h urine samples collected from 800 participants in four clinical sites across Canada in the Prospective Urban and Rural Epidemiological (PURE) study. Urinary iodide together with thiocyanate and nitrate were measured using a validated capillary electrophoresis assay. Protective/risk factors associated with iodine deficiency were identified using a binary logistic regression model, whereas daily urinary iodine concentration (24 h UIC, μg/L) and urinary iodine excretion (24 h UIE, μg/day) were compared using complementary statistical methods with covariate adjustments. Overall, our Canadian adult cohort had adequate iodine status as reflected by a median UIC of 111 μg/L with 11.9% of the population <50 μg/L categorized as having moderate to severe iodine deficiency. Iodine adequacy was also evident with a median 24 h UIE of 226 μg/day as a more robust metric of iodine status with an estimated average requirement (EAR) of 7.1% (< 95 μg/day) and a tolerable upper level (UL) of 1.8% (≥1100 μg/day) based on Canadian dietary reference intake values. Participants taking iodine supplements (OR = 0.18; p = 6.35 × 10−5), had greater 24 h urine volume (OR = 0.69; p = 4.07 × 10−4), excreted higher daily urinary sodium (OR = 0.71; p = 3.03 × 10−5), and/or were prescribed thyroxine (OR = 0.33; p = 1.20 × 10−2) had lower risk for iodine deficiency. Self-reported intake of dairy products was most strongly associated with iodine status (r = 0.24; p = 2.38 × 10−9) after excluding for iodine supplementation and T4 use. Participants residing in Quebec City (OR = 2.58; p = 1.74 × 10−4) and Vancouver (OR = 2.54; p = 3.57 × 10−4) were more susceptible to iodine deficiency than Hamilton or Ottawa. Also, greater exposure to abundant iodine uptake inhibitors from tobacco smoking and intake of specific goitrogenic foods corresponded to elevated urinary thiocyanate and nitrate, which were found for residents from Quebec City as compared to other clinical sites. Recent public health policies that advocate for salt restriction and lower dairy intake may inadvertently reduce iodine nutrition of Canadians, and further exacerbate regional variations in iodine deficiency risk.

Adherence to the Mediterranean Diet as a Modifiable Risk Factor for Thyroid Nodular Disease and Thyroid Cancer: Results From a Pilot Study

Iodine deficiency is the most important established nutritional risk factor for the development of thyroid nodular disease. Nevertheless, to the best of our knowledge, to date no study focused on the association between the adherence to the Mediterranean diet (MD) and thyroid nodular disease. Adherence to the MD was evaluated using the PREvención con DIetaMEDiterránea (PREDIMED) questionnaire. Physical activity, smoking habits, and anthropometric parameters were studied. PREDIMED was used to evaluate the degree of adherence to the MD. Evaluation of fine needle aspiration cytology of thyroid lesions based on 2013 Italian thyroid cytology classification system. Cytology of thyroid nodules was carried out through sonography-guided fine-needle aspiration and patients were divided into 5 categories: TIR2, TIR3a, TIR3b, TIR4, and TIR5. The study population consisted of 794 subjects (554 females, 69.8%), aged 18–65 years, with BMIs ranging from 19.4 to 55.3 kg/m². Thyroid nodular disease was present in 391 participants (49.2%), and the most frequent cytological categories was TIR2 (18.3 %), followed by a TIR4 (8.9 %). The presence of thyroid nodules was also significantly associated with the lowest adherence to the MD (OR 6.16, p < 0.001). Patients with TIR5 had the lower adherence to the MD (2.15 ± 1.12 score) compared to other TIRs (p < 0.001). The cytological category with high-risk of malignancy (TIR4/TIR5) was significantly associated with the lowest adherence to the MD (OR 137.55, p < 0.001) and PREDIMED score (OR = 0.33, p < 0.001, 95% IC = 0.26–0.41, R² = 0.462). At multiple regression analysis, PREDIMED score was the main predictor of both the presence of nodules (p < 0.001) and the cytological category with high-risk of malignancy (p < 0.001). At ROC analysis PREDIMED score ≤ 5 and ≤ 4 (p = 0.001) were the values that predicted the presence of thyroid nodular disease and cytological category with high-risk of malignancy, respectively. In conclusion, our study demonstrated that the low adherence to the MD is associated with the presence of thyroid nodular disease and in particular with those at high-risk of malignancy.

Thyroid dysfunction in Greece: Results from the national health examination survey EMENO

Background

Nationwide data on thyroid disease prevalence in Greece is lacking. Using the national health examination survey EMENO data resources, we aimed to estimate the prevalence of hypothyroidism and hyperthyroidism and associated risk factors in adults living in Greece.

Methods

A random sample of the adults (≥18 years) living in Greece was drawn by multi-stage stratified random sampling based on the 2011 census. During home visits, trained interviewers administered a standardized questionnaire to study participants. All participants answered questions concerning demographic parameters (e.g., age, sex, degree of urbanization, income) and questions concerning smoking habits, alcohol, dietary habits and psychological parameters such as anxiety and thyroid disease. Weighted logistic regression models were fitted to assess factors associated with thyroid disease.

Results

In total, 6006 individuals were recruited in the Greek Health Examination Survey EMENO (response rate 72%) of whom 5981 were eligible for this study. The prevalence of thyroid disease was 9%, where 0.4% was related to hyperthyroidism and 8.6% to hypothyroidism. The prevalence of thyroid disease was higher in women (14.9%) than men (2.7%) (p<0.001). The highest rates of thyroid disease were observed in former iodine-deficient areas. A decrease in the prevalence of thyroidopathies with increasing alcohol consumption was found. Thyroid disease was associated with anxiety in men. Multivariable regression analysis showed that age, geographic area, and smoking were related to thyroid disease.

Conclusion

The prevalence of thyroid disease in Greece is higher in women. Age, habits, and characteristics of geographic areas determine the distribution of thyroidopathies in Greece.

Recent advancements in the measurement of pathogenic airborne viruses

Air-transmissible pathogenic viruses, such as influenza viruses and coronaviruses, are some of the most fatal strains and spread rapidly by air, necessitating quick and stable measurements from sample air volumes to prevent further spread of diseases and to take appropriate steps rapidly. Measurements of airborne viruses generally require their collection into liquids or onto solid surfaces, with subsequent hydrosolization and then analysis using the growth method, nucleic-acid-based techniques, or immunoassays. Measurements can also be performed in real time without sampling, where species-specific determination is generally disabled. In this review, we introduce some recent advancements in the measurement of pathogenic airborne viruses. Air sampling and measurement technologies for viral aerosols are reviewed, with special focus on the effects of air sampling on damage to the sampled viruses and their measurements. Measurement of pathogenic airborne viruses is an interdisciplinary research area that requires understanding of both aerosol technology and biotechnology to effectively address the issues. Hence, this review is expected to provide some useful guidelines regarding appropriate air sampling and virus detection methods for particular applications.

Changes in Smoking, Alcohol Consumption, and the Risk of Thyroid Cancer: A Population-Based Korean Cohort Study

Simple Summary

The inverse association between smoking, alcohol intake, and thyroid cancer has been suggested by observational studies. From the representative data in Korea, we identified the epidemiologic evidence to elucidate the true effect between smoking, alcohol intake, and thyroid cancer incidence by exploring the effect of changes in smoking and alcohol consumption habits.

Abstract

To elucidate potential causality between smoking and alcohol intake on thyroid cancer incidence, we explored the effect of changes in smoking and alcohol consumption habits. From the Korean National Health Insurance database, we identified 4,430,070 individuals who participated in the national health screening program in 2009 and 2011. The level of smoking and alcohol consumption was measured twice, once in 2009 and again in 2011. The risk of thyroid cancer according to their changes was estimated using the Cox proportional hazard model. During the mean follow-up period of 6.32 ± 0.72 years, 29,447 individuals were diagnosed with thyroid cancer. Compared to those who sustained not smoking, non-smokers who initiated smoking to light (adjusted hazard ratio (aHR) 0.96, 95% confidence interval (CI) 0.81–1.15), moderate (aHR 0.90, 95% CI 0.78–1.04), and heavy level (aHR 0.81, 95% CI 0.69–0.96) had a decreased risk of thyroid cancer. Heavy smokers who quit smoking had an increased risk of thyroid cancer (aHR 1.23, 95% CI 1.06–1.42) compared to those who sustained heavy smoking. Change in drinking status was not significantly associated with thyroid cancer risk compared to drinking at the same level, although a non-significant trend of increased risk was noted in quitters. Participants who initiated both smoking and drinking (HR 0.80, 95% CI 0.69–0.93) had a lower risk of thyroid cancer compared with those who continued not to smoke and drink. Our findings provide further evidence that smoking, and possibly alcohol consumption, would have true protective effects on the development of thyroid cancer.

Diet as a possible influencing factor in thyroid cancer incidence: the point of view of the nutritionist

The incidence of differentiated thyroid cancer has increased in the last decades all over the world. Different environmental factors are possible perpetrators of this exponential growth. Nutritional factors are among the main environmental factors studied for thyroid cancer in recent years. This review aims to overview the main dietary factors involved in thyroid cancer risk, providing specific nutrition recommendations from the endocrinological Nutritionist point of view. Among the single food, fish and shellfish are the primary natural source of iodine, selenium and vitamin D in the human diet. These nutrients are essential for the synthesis of thyroid hormones; however, their consumption is not consistently related to thyroid cancer risk. The high intake of fruit and vegetables, probably due to their vitamin and antioxidant content, shows a weak inverse association with thyroid cancer risk. Alcohol, meat, or other food groups/nutrients showed no significant effect on thyroid cancer. In conclusion, to date, no definite association among dietary factors, specific dietary patterns, and thyroid cancer, and its clinical severity and aggressiveness have been found. However, it is essential to underline that in the future, prospective studies should be carried out to precisely evaluate the qualitative and quantitative intake of nutrients by patients to establish with more confidence a potential correlation between food intake and the occurrence and development of thyroid cancer.

Obesity is positively related and tobacco smoking and alcohol consumption are negatively related to an increased risk of thyroid cancer

The purpose of this study was to evaluate the relationships of smoking, alcohol consumption, and obesity with thyroid cancer in Korean residents. The Korean National Health Insurance Service-Health Screening Cohort includes individuals ≥ 40 years who were assessed from 2002 to 2013. In total, 4977 thyroid cancer participants were matched with respect to age, sex, income, and region of residence with 19,908 controls at a ratio of 1:4. Crude and adjusted (for the Charlson comorbidity index, smoking status, frequency of alcohol consumption, and obesity) odds ratios (ORs) were analyzed using conditional logistic regression analyses. Additionally, 95% confidence intervals (CIs) were calculated. The adjusted OR of smoking for thyroid cancer was 0.62 (95% CI 0.54–0.72, P < 0.001), and that of alcohol consumption was 0.83 (95% CI 0.75–0.92, P < 0.001). The adjusted ORs of the BMI categories were 1.13 (95% CI 1.05–1.22, P = 0.002) for obese I, and 1.24 (95% CI 1.04–1.47, P = 0.014) for obese II. The ORs of smoking and alcohol consumption were lower, and those of overweight and obesity were higher in thyroid cancer patients than in individuals in the control group.

An evaluation of urine and serum iodine status in the population of Tibet, China: No longer an iodine-deficient region

OBJECTIVES

Iodine is a critical trace element for the synthesis of thyroid-related hormones, and either low or high iodine status can lead to thyroid dysfunction. This study aimed to evaluate the iodine status of the Tibetan population.

METHODS

From September 2016 to August 2018, we enrolled 1499 healthy adults from three areas of varying altitudes in Tibet. Urine iodine concentrations (UICs), adjusted UICs, and serum iodine concentrations (SICs) were measured using inductively coupled plasma mass spectrometry.

RESULTS

The median UIC, adjusted UIC, and SIC was 137.9 μg/L, 118.4 µg/gCr, and 58.3 μg/L, respectively. Of the participants, 30.4% had UICs <100 µg/L, 63.0% had UICs ranging from 100 to 300 µg/L, and 9.6% had UICs >300 µg/L. The correlation between UIC, adjusted UIC, and SIC was good (r > 0.65, P < 0.01). The SICs were more stable than the UICs, and were not associated with age or sex. The prevalence of clinical hyperthyroidism, clinical hypothyroidism, subclinical hyperthyroidism, subclinical hypothyroidism, positive thyroid peroxide antibody, positive thyroglobulin antibody, either positive and both positive was 0.5%, 1.3%, 1.7% and 17.9%, 9.3%, 6.5%, 12.5%, and 2.5%, respectively. The prevalence of almost all thyroid disorders was higher in women than in men.

CONCLUSION

This multicenter cross-sectional study found that the human iodine status of adults in Tibet was considered adequate, based on the World Health Organization's criteria.

AATF and SMARCA2 are associated with thyroid volume in Hashimoto's thyroiditis patients

Thyroid volume of Hashimoto’s thyroiditis (HT) patients varies in size over the course of disease and it may reflect changes in biological function of thyroid gland. Patients with subclinical hypothyroidism predominantly have increased thyroid volume whereas patients with more pronounced hypothyroidism have smaller thyroid volumes. Suggested mechanism for thyroid atrophy is thyrocyte death due to apoptosis. We performed the first genome-wide association study (GWAS) of thyroid volume in two groups of HT patients, depending on levothyroxine (LT4) therapy, and then meta-analysed across. Study included 345 HT patients in total and 6 007 322 common autosomal genetic variants. Underlying hypothesis was that genetic components that are involved in regulation of thyroid volume display their effect in specific pathophysiologic conditions of thyroid gland of HT patients. We additionally performed immunohistochemical analysis using thyroid tissues and analysed differences in expression levels of identified proteins and apoptotic marker between HT patients and controls. We found genome-wide significant association of two loci, both involved in apoptosis, with thyroid volume of HT patients: rs7212416 inside apoptosis-antagonizing transcription factor AATF (P = 8.95 × 10⁻⁹) and rs10738556 near chromatin-remodeling SMARCA2 (P = 2.83 × 10⁻⁸). In immunohistochemical analysis we observed that HT patients with homozygous AATF risk genotypes have decreased AATF expression (0.46-fold, P < 0.0001) and increased apoptosis (3.99-fold, P = 0.0001) in comparison to controls. HT patients with heterozygous SMARCA2 genotypes have decreased SMARCA2 expression, albeit without reaching statistical significance (1.07-fold, P = 0.5876), and significantly increased apoptosis (4.11-fold, P < 0.0001). By two lines of evidence we show that two highly plausible genetic loci, AATF and SMARCA2, may be involved in determining the thyroid volume of HT patients. The results of our study significantly add to the current knowledge of disturbed biological mechanisms in thyroid gland of HT patients.

Hypothyroidism and nonalcoholic fatty liver disease - a chance association?

Background Nonalcoholic fatty liver disease (NAFLD) defines the clinical-pathological spectrum of hepatic lipotoxicity, which may progress to hepatic fibrosis and its complications. Thyroid hormone is a master regulator of cell metabolism and body fat distribution. Whether hypothyroidism is associated or not with an increased risk of developing NAFLD and its fibrotic progression is both clinically and physiopathologically relevant. Indeed, answering this research question would carry major pathogenic and therapeutic implications. Method PubMed database was searched using relevant key-words such as hypothyroidism; NAFLD; nonalcoholic steatohepatitis; cirrhosis; hepatocellular carcinoma; epidemiology; pathogenesis; natural history. The epidemiological studies and the meta-analyses published so far were identified as well as those studies addressing the physiopathology underlying this association. Results Many observational studies have investigated the association between either subclinical or overt hypothyroidism and NAFLD. Data are conflicting: some original and meta-analytical studies demonstrated that hypothyroidism, (mainly subclinical hypothyroidism), was common, occurring in approximately 25% of individuals with imaging-defined or biopsy-proven NAFLD; other studies, however, failed to identify a significant association between hypothyroidism and NAFLD. Moreover, such an association is biologically plausible based on the specific physiopathological impact of thyroid hormone and thyroid stimulating hormone (TSH) on metabolism of hepatocytes and accumulation and distribution of body fat. Conclusions The findings from the present review support a significant association between primary hypothyroidism and risk of development and progression of NAFLD. However, further studies evaluating the relative importance of subclinical versus overt hypothyroidism as well as addressing the mechanisms underlying the association of hypothyroidism with NAFLD are eagerly awaited.

Thyroid nodules in centenarians: prevalence and relationship to lifestyle characteristics and dietary habits

Background

Thyroid nodules (TNs) are common thyroid lesions in older population. Few studies have focused on the prevalence of TNs and their relationship to lifestyle characteristics and dietary habits in centenarians. The current study aimed at determining the prevalence of TNs in Chinese centenarians by using high-resolution ultrasound (US) equipment and at investigating its relationship to lifestyle characteristics and dietary habits.

Participants and methods

The current study was part of the China Hainan Centenarian Cohort Study that was conducted in Hainan, an iodine-sufficient region in People’s Republic of China. A total of 874 permanent residents aged ≥100 years (mean age =102.8±2.8 years) without any missing data were included in the analysis.

Results

Among the participants, 649 of them were detected at least one TN under the US examinations. The overall prevalence rate of TNs was 74.3%. The prevalence of TNs was higher in participants who were women, had hypertension, had diabetes, and were underweight compared with their counterparts. Multivariate logistic regression analyses showed that being female, hypertensive, and diabetic; betel quid consumption; and red meat consumption were independent risk factors, while being underweight and nut consumption were independent protective factors for TNs.

Conclusion

Our findings indicate that the presence of TNs was highly prevalent in Chinese centenarians, particularly in women. In addition to gender, having hypertension, having diabetes, and being underweight, the presence of TNs was independently associated with betel quid, red meat, and nut consumption. Further prospective studies are warranted to verify these associations in populations from different age strata, races, cultures, and iodine supplementation.

Interaction between alcohol consumption and methylenetetrahydrofolate reductase polymorphisms in thyroid cancer risk: National Cancer Center cohort in Korea

The effect of alcohol intake on thyroid cancer is unestablished, and its interaction effects with genetic susceptibility are unclear. In this case-control study, the relationship among alcohol intake, the methylenetetrahydrofolate reductase (MTHFR) gene, and thyroid cancer risk has been evaluated. In total, 642 cases and 642 controls of Korean origin were included, and the genetic variants C677T and A1298C of the MTHFR gene were analysed. The interactions between alcohol-consumption behaviour and genetic variants were analysed with a likelihood ratio test, wherein a multiplicative interaction term was added to a logistic regression model. There was an independent association between the C677T polymorphism and thyroid cancer risk but not for drinking history. For C677T C/C homozygotes, individuals with a history of alcohol consumption showed a protective OR (95% CI) of 0.42 (0.15–1.13) when never drinkers were used as the reference. However, this protective association was not observed among individuals with a T+ allele with an OR (95% CI) of 1.27 (0.89–1.82), showing different directions for the association between genotypes with a significant interaction (P_interaction = 0.009). Based on the genetic characteristics of individuals included, an interaction between alcohol intake and MTHFR C677T may modify the risk of thyroid cancer.

Trends in Costs of Thyroid Disease Treatment in Denmark during 1995-2015

BACKGROUND

Iodine fortification (IF) may contribute to changes in costs of thyroid disease treatment through changes in disease patterns. From a health economic perspective, assessment of the development in costs of thyroid disease treatment in the population is pertinent.

OBJECTIVES

To assess the trends in annual medicine and hospital costs of thyroid disease treatment during 1995-2015 in Denmark, i.e., before and after the introduction of mandatory IF in 2000.

METHODS

Information on treatments for thyroid disease (antithyroid medication, thyroid hormone therapy, thyroid surgery, and radioiodine treatment) was obtained from nationwide registers. Costs were valued at 2015 prices using sales prices for medicines and the Danish Diagnosis-Related Group (DRG) and Danish Ambulatory Grouping System (DAGS) tariffs of surgeries/radioiodine treatments. Results were adjusted for changes in population size and age and sex distribution.

RESULTS

The total direct medicine and hospital costs of thyroid disease treatment increased from EUR ∼190,000 per 100,000 persons in 1995 to EUR ∼270,000 per 100,000 persons in 2015. This was mainly due to linearly increased costs of thyroid hormone therapy and increased costs of thyroid surgery since 2008. Costs of antithyroid medication increased slightly and transiently after IF, while costs of radioiodine treatment remained constant. Costs of thyroid hormone therapy and thyroid surgery did not follow the development in the prevalence of hypothyroidism and structural thyroid diseases observed in concurrent studies.

CONCLUSION

The costs of total direct medicine and hospital costs for thyroid disease treatment in Denmark increased from 1995 to 2015. This is possibly due to several factors, e.g., changes in treatment practices, and the direct effect of IF alone remains to be estimated.

A meta-analysis of alcohol consumption and thyroid cancer risk

Background

It is still inconclusive whether alcohol consumption affects the risk of thyroid cancer. We conducted a meta-analysis of available epidemiological data to address this issue.

Results

Compared with nondrinkers, the pooled relative risks (RRs) and corresponding 95% confidential intervals (CIs) of thyroid cancer were 0.80 (95% CI 0.71-0.90) for any drinkers, 0.81 (95% CI 0.70-0.93) for light and 0.71 (95% CI 0.63-0.79) for moderate drinkers. The dose–response analysis suggested that there is no evidence of a dose-risk relationship between alcohol intaking and thyroid cancer risk (P = 0.112).

Methods

Eligible studies were identified by searching PubMed and EMbase databases. A total of 24 studies, included 9,990 cases with thyroid cancer, were included in this meta-analysis. We defined light alcohol intake as ≤ one drink/day and moderate as >one drink/day. The summary risk estimates were calculated by the random effects model. A dose-response analysis was also conducted for modeling the dose-risk relation.

Conclusion

This meta-analysis confirmed an inverse association between alcohol consumption and thyroid cancer risk. Further studies are needed to better understand the potential mechanisms underlying this association.

Thyroid Hormone Levels in Chronic Alcoholic Liver Disease Patients Before and After Treatment

INTRODUCTION

Alcoholic liver disease affects almost all aspects of the thyroid gland including the thyroid hormone levels and the thyroid gland size. The altered thyroid hormone levels in alcoholic liver disease may affect alcohol abstinence in withdrawal period by changing hormone milieu in brain, increasing withdrawal dysphoria and increasing craving.

AIM

The aim of the present study was to assess and compare the levels of thyroid hormones- free T3, free T4, Thyroid Stimulating Hormone (TSH) and Gamma Glutamyl Transferase (GGT) in chronic alcoholic liver disease patients before and after treatment.

MATERIALS AND METHODS

This study was conducted on 70 alcoholic liver disease patients. Two serum samples were taken from the patient once at the time of admission and the other at the time of discharge after atleast ten days of treatment. Serum free T3, free T4, TSH and GGT were assessed on auto analyzer Beckman Coulter. Statistical analysis is done by paired t-test and Pearson's Correlation test.

RESULTS

In present study, serum GGT levels decreased significantly (before treatment-207.46±66.90 U/L; after treatment-78.47±19.71 U/L) and free T3 levels increased significantly with treatment (before treatment-2.54±0.48 pg/mL; after treatment-2.88±0.37 pg/mL). Free T4 levels are also increased with treatment (before treatment-0.78±0.19 ng/dL; after treatment-0.88±0.13 ng/dL) and TSH levels are not altered significantly with treatment (before treatment-3.34±1.62 μIU/mL; after treatment-3.32±1.51 μIU/mL). Additionally, free T3 showed a significant correlation with GGT before (p-value<0.001) and after treatment (p-value-0.003) and free T4 and TSH showed a significant correlation with GGT after treatment (free T4: p-value<0.001) (TSH: p-value <0.001) and a suggestive significance exists before treatment (free T4: p-value= 0.098) (TSH: p-value=0.062).

CONCLUSION

Thyroid hormones levels, particularly free T3 and free T4, need to be evaluated in chronic alcoholic liver disease patients. Free T3 could be used as a marker of alcoholism and is very useful in assessing the treatment efficacy in chronic alcoholic liver disease. Also, assessing free thyroid hormones is necessary during the withdrawal and abstinent periods as decreased hormone levels may increase withdrawal effects and craving for alcohol.

Comparison of breast-milk iodine concentration of lactating women in Australia pre and post mandatory iodine fortification

OBJECTIVE

To compare the breast-milk iodine concentrations (BMIC) of lactating women before and after the mandatory iodine fortification of bread in Australia in 2009.

DESIGN

Cross-sectional study. Breast milk samples were collected from two cohorts of women in South Australia within 7 d of delivery to determine BMIC. The percentage of samples with iodine concentration below 100 µg/l, a level considered adequate for breast-fed infants, was calculated. Sociodemographic information and intake of dietary supplements were obtained from all women.

SETTING

The breast milk samples were collected between 2006 and 2007 in the pre-fortification cohort and between 2012 and 2013 in the post-fortification cohort.

RESULTS

The median (interquartile range) BMIC was higher in the post-fortification samples compared with samples collected in the pre-fortification period (187 (130-276) v. 103 (73-156) µg/l; P<0·05). Overall, the percentage of women with BMIC <100 µg/l was lower in the post-fortification cohort than in the pre-fortification cohort (13 v. 49 %; P<0·01). The percentage of women with BMIC <100 µg/l in the post-fortification cohort was lower among women who took iodine supplements in pregnancy (12 v. 29 %; P<0·01).

CONCLUSIONS

Mandatory iodine fortification of bread has resulted in an increase in the iodine content of breast milk in Australian women. However, iodine supplementation may still be required in some women post-iodine fortification to reach the level of BMIC that is considered adequate to meet the iodine requirement of full-term infants.

Alcohol Intake and Risk of Thyroid Cancer: A Meta-Analysis of Observational Studies

Purpose

The purpose of this study was to assess whether alcohol intake is associated with the risk of thyroid cancer by a meta-analysis of observational studies.

Materials and Methods

We searched PubMed and EMBASE in June of 2015 to locate eligible studies. We included observational studies such as cross-sectional studies, case-control studies, and cohort studies reporting odd ratios (ORs) or relative risk (RRs) with 95% confidence intervals (CIs).

Results

We included 33 observational studies with two cross-sectional studies, 20 case-controls studies, and 11 cohort studies, which involved a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer in the final analysis. In the fixed-effect model meta-analysis of all 33 studies, we found that alcohol intake was consistently associated with a decreased risk of thyroid cancer (OR or RR, 0.74; 95% CI, 0.67 to 0.83; I²=38.6%). In the subgroup meta-analysis by type of study, alcohol intake also decreased the risk of thyroid cancer in both case-control studies (OR, 0.77; 95% CI, 0.65 to 0.92; I²=29.5%; n=20) and cohort studies (RR, 0.70; 95% CI, 0.60 to 0.82; I²=0%; n=11). Moreover, subgroup meta-analyses by type of thyroid cancer, gender, amount of alcohol consumed, and methodological quality of study showed that alcohol intake was significantly associated with a decreased risk of thyroid cancer.

Conclusion

The current meta-analysis of observational studies found that, unlike most of other types of cancer, alcohol intake decreased the risk of thyroid cancer.

Risk Factors for Thyroid Cancer: A Hospital-Based Case-Control Study in Korean Adults

PURPOSE

Although the incidence of thyroid cancer in Korea has rapidly increased over the past decade, few studies have investigated its risk factors. This study examined the risk factors for thyroid cancer in Korean adults.

MATERIALS AND METHODS

The study design was a hospital-based case-control study. Between August 2002 and December 2011, a total of 802 thyroid cancer cases out of 34,211 patients screened from the Cancer Screenee. Cohort of the National Cancer Center in South Korea were included in the analysis. A total of 802 control cases were selected from the same cohort, and matched individually (1:1) by age (±2 years) and area of residence for control group 1 and additionally by sex for control group 2.

RESULTS

Multivariate conditional logistic regression analysis using the control group 1 showed that females and those with a family history of thyroid cancer had an increased risk of thyroid cancer, whereas ever-smokers and those with a higher monthly household income had a decreased risk of thyroid cancer. On the other hand, the analysis using control group 2 showed that a family history of cancer and alcohol consumption were associated with a decreased risk of thyroid cancer, whereas higher body mass index (BMI) and family history of thyroid cancer were associated with an increased risk of thyroid cancer.

CONCLUSION

These findings suggest that females, those with a family history of thyroid cancer, those with a higher BMI, non-smokers, non-drinkers, and those with a lower monthly household income have an increased risk of developing thyroid cancer.

Constraints on Biological Mechanism from Disease Comorbidity Using Electronic Medical Records and Database of Genetic Variants

Patterns of disease co-occurrence that deviate from statistical independence may represent important constraints on biological mechanism, which sometimes can be explained by shared genetics. In this work we study the relationship between disease co-occurrence and commonly shared genetic architecture of disease. Records of pairs of diseases were combined from two different electronic medical systems (Columbia, Stanford), and compared to a large database of published disease-associated genetic variants (VARIMED); data on 35 disorders were available across all three sources, which include medical records for over 1.2 million patients and variants from over 17,000 publications. Based on the sources in which they appeared, disease pairs were categorized as having predominant clinical, genetic, or both kinds of manifestations. Confounding effects of age on disease incidence were controlled for by only comparing diseases when they fall in the same cluster of similarly shaped incidence patterns. We find that disease pairs that are overrepresented in both electronic medical record systems and in VARIMED come from two main disease classes, autoimmune and neuropsychiatric. We furthermore identify specific genes that are shared within these disease groups.

The Prevalence of Thyroid Nodules and an Analysis of Related Lifestyle Factors in Beijing Communities

Thyroid nodules (TNs) have annual increasing trends worldwide, and large-scale investigations on the prevalence of TNs in Beijing communities have not been conducted since the introduction of salt iodization in 1995. We performed a cross-sectional study to determine the prevalence of TNs, their epidemiological characteristics, and their correlation with lifestyle factors. A total of 6324 permanent residents aged 18 years or older (mean age, 52.15 ± 11.58 years) from seven representative communities in Beijing were included in the analyses. Once informed consent was obtained, the subjects were asked to complete questionnaires, a physical examination, and thyroid ultrasound. A total of 3100 cases had TNs. The overall prevalence rate was 49.0%, and the age-standardized prevalence was 40.1%, which increased significantly as age increased (p < 0.001). The prevalence was significantly higher in females compared to males (p < 0.001), and it was significantly higher among female current smokers and former smokers compared to non-smokers (p = 0.007). There was no correlation between alcohol consumption and TNs, and there were no significant differences in the prevalence among different groups of taste preference. The prevalence decreased with an increased frequency of seafood intake (p = 0.015) and with higher literacy levels (p < 0.001). The Cochran-Armitage trend test showed that the prevalence significantly increased with decreased physical labor and exercise intensity (p < 0.001, p = 0.009). Logistic regression analysis showed that age (Odds ratio (OR) = 1.039 (1.034-1.044), p < 0.001), the female sex (OR = 1.789 (1.527-2.097)), Body mass index (BMI) (OR = 1.019 (1.005-1.034)), and current smoking habits (OR = 1.246 (1.046-1.483)) were independent risk factors for TNs. Our findings indicate that there is a high prevalence of TNs in Beijing, with a higher prevalence in females than in males. Moreover, the prevalence increases as age increases. Smoking and BMI are independent risk factors for TNs. Therefore, intervention against smoking and weight loss might help reduce the risk of TN occurrence.

Alcoholic beverage consumption contributes to caloric and moisture intakes and body weight status

OBJECTIVES

This study provides cross-sectional information on alcoholic beverages as potential sources of moisture and calories for drinkers in the United States. Associations between number of drinks per day and body weight status were also studied.

METHODS

Multivariable regression models were used to ascertain associations while controlling for potential confounders.

RESULTS

Compared to nondrinkers, daily moisture intake increased as the number of drinks increased. Increase in daily moisture intake of drinkers remained significant even after correcting for diuretic effects of ethanol (men: 270.6 g [95% confidence interval (CI), 115.7-425.4], P = 0.001) and (women: 193.0 g [95% CI, 76.8-309.4], P = 0.002). The increase in daily moisture intake after correcting for diuretic losses were men: 3.9% to 9.6%; and women: 4.1% to 12.8% depending on number of drinks. The increase in calorie intake was 6.7% to 16.2% of men's, and 6.4% to 16.0% of women's daily intake. Compared to nondrinking counterparts, men who consumed 2 or more drinks per day were more likely to be overweight whereas men who consumed 4 or more drinks per day were more likely to be obese (odds ratio: 1.63 [95% CI, 1.10-2.40], P = 0.015). Women at all levels of drinking were less likely to be obese (odds ratio: 0.70 [95% CI, 0.55-0.88], P = 0.004) compared to nondrinking counterparts.

CONCLUSION

Alcoholic beverages contribute to moisture intake despite the diuretic effect of their ethanol content. Calorie intake increase with increasing alcohol intake among men and women but only men associate with increased likelihood of overweight and obesity. Women drinkers associate with lower body mass index and are less likely to be overweight or obese.

Modifiable risk factors and thyroid cancer

OBJECTIVE

To evaluate the association between modifiable patient risk factors including tobacco use, alcohol consumption, body mass index (BMI), and thyroid cancer.

STUDY DESIGN

Retrospective study with chart review.

SETTING

Midwest university hospital.

SUBJECTS AND METHODS

Retrospective study comparing Midwest patients with thyroid cancer from our Thyroid Tumor and Cancer Registry with Midwest controls without a personal history of cancer. Descriptive statistics were created from patient questionnaires and chart reviews. Odds ratios (ORs) were reported for significant associations.

RESULTS

There were 467 patients with cancer and 255 controls. The thyroid cancer group included 404 papillary, 47 follicular, 13 medullary, and 3 anaplastic cancers. When comparing all patients with cancer with controls, smoking more than 100 lifetime cigarettes was associated with a reduced cancer risk (OR, 0.68; 95% confidence interval [CI], 0.50-0.94). Secondhand smoke exposure did not show a statistically significant relationship to thyroid cancer. Compared with never drinking, current drinking was associated with a reduced cancer risk (OR, 0.46; 95% CI, 0.29-0.73) as was consuming 1 to 2 drinks daily compared to drinking <1 drink daily (OR, 0.58; 95% CI, 0.34-0.89). There was no difference between median BMI at age 20 years, lifetime maximum BMI, or current BMI between patients with cancer and controls.

CONCLUSION

Our data showed no positive correlation between tobacco use, alcohol consumption, or obesity and thyroid cancer risk. Our data suggest that tobacco use and mild alcohol consumption may be associated with a slightly reduced risk of thyroid cancer. There was no association between BMI and thyroid cancer in our study population.

Evolution of benign thyroid nodules under levothyroxine non-suppressive therapy

BACKGROUND

Non-suppressive or partially suppressive L-T4 treatment demonstrated to be effective in reducing the volume of the nodules. However, studies with long follow-up are lacking and significant controversy exists regarding the efficacy of non-suppressive L-T4 treatment in benign nodular goiter.

AIM

The goal of this study was to determine the evolution of thyroid nodules in subjects treated with a non-suppressive levothyroxine (L-T4) dose, compared to untreated subjects.

DESIGN AND PATIENTS

We followed for a period of 1-9 years the thyroid nodule size in 356 female patients in the age range 19-45 at study entry, of which 201 untreated (Group 0) and 165 treated with a non-suppressive L-T4 dose (Group L-T4).

MEASUREMENTS

We determined the volume of thyroid nodules by ultrasonography.

RESULTS

The initial mean nodule volume in Group 0 and Group L-T4 was 3.91 ± 6.87 and 4.01 ± 7.35 mL, respectively. Nodule volume increase was inversely correlated to the initial volume. The final volume was slightly higher in untreated than in L-T4 treated subjects (5.37 ± 8.49 and 4.39 ± 6.72 mL). In both groups, the mean of annual fold increase of nodule volume was inversely correlated with the follow-up duration (P < 0.0046), indicating a slower growth as time advances. In the subjects treated with L-T4, the mean annual increase of nodule volume was significantly minor compared to untreated subjects. Concomitant nodules in ten multinodular goiters exhibited totally independent evolution, demonstrating that intranodular factors are more important for the nodule behavior than extra nodular factors.

CONCLUSIONS

Our study demonstrates that the growth of benign thyroid nodules is inversely correlated to their size, benign nodules naturally growth slowly as time advances, and that a chronic treatment with L-T4 at a non-TSH-suppressive dose significantly reduces their growth.

Genetic and non-iodine-related factors in the aetiology of nodular goitre

Genetic and a large number of environmental non-iodine-related factors play a role in the cause of nodular goitre. Most evidence for the influence of genetic and environmental factors in the cause of goitre is from cross-sectional, population-based studies. Only a few studies have included prospective data on risk factors for nodular goitre, although few prospective data are available on the effect of iodine and tobacco smoking on goitre development. Goitre is not one single phenotype. Many epidemiological studies do not distinguish diffuse from nodular goitre, as the investigated parameter is often thyroid volume or frequency with increased thyroid volume. Moreover, information on the presence and effect of gene-environment, gene-gene, and environment-environment effect modifications is limited. Thus, firm conclusions about the relative contributions and causality of the investigated risk factors should be made with caution. Smoking seems to be an established risk factor for nodular goitre, possibly with effect modification from iodine intake, as the risk associated with smoking is smaller or absent in areas with sufficient iodine intake. The use of oral contraceptives might have protective effects against goitre, and childbirth is an increased risk factor for goitre in areas with non-optimal iodine intake. Insulin resistance is a recently investigated risk factor, and the risk of goitre may be reversible with metformin treatment. Iodine remains the major environmental risk factor for nodular goitre.

Wine, Food and Health

Wine has historically been associated with religious rights, used as a salubrious beverage, employed as a medication as well as a medicinal solvent, and consumed as a food accompaniment. It is the latter that is most intimately associated in the minds of most modern consumers. Despite this, there is little flavor commonality on which pairing could be based. The first section of the chapter examines this feature, and wine’s primary role as a palate cleanser and food condiment. The synergistic role of food and wine in suppressing each other’s least pleasant attributes is also explained. The final section deals with the latest evidence relating to the many beneficial health effects of moderate wine consumption, shortfalls in the data, headache induction, dental erosion, and conditions under which wine intake is contraindicated.

Impact of alcohol use on thyroid function

Alcohol is one of the commonest illicit psychoactive substances consumed globally and is the world's third largest risk factor for disease and disability. It has been reported to have multiple effects on the hypothalamo-pituitary-thyroid axis and the functioning of the thyroid gland. It has been reported to cause direct suppression of thyroid function by cellular toxicity, and indirect suppression by blunting thyrotropin-releasing hormone response. It causes a decrease of peripheral thyroid hormones during chronic use and in withdrawal. Alcohol use may also confer some protective effect against thyroid nodularity, goiter, and thyroid cancer. This article presents a review of the clinically relevant effects of alcohol on the functioning of the thyroid gland and also discusses the effect of medication used in treatment of alcohol dependence on thyroid function.

Prevention of autoimmune hypothyroidism by modifying iodine intake and the use of tobacco and alcohol is manoeuvring between Scylla and Charybdis

Although autoimmune hypothyroidism has generally been considered to be a disease that mainly develops because of genetic aberrations and for which adjustment of environment would bring about but slight risk modification, this understanding is increasingly appearing to be incorrect. We describe how iodine intake, smoking cessation and alcohol intake are all strong modifiers of risk that, combined, may influence risk by a factor of up to 30. Unfortunately, promotion of an environment leading to substantial lowering of the risk of autoimmune hypothyroidism (i.e. improvement of dietary iodine deficiency, decrease or cessation of smoking, and moderate alcohol intake) is not incorporated within current public health promoting programs. Nevertheless, it is increasingly becoming evident that knowledge of the importance of these factors for disease development is likely to assist in the planning of health promotion programs, while it will surely also be of value in the care of individual patients.

Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.

Moderate alcohol consumption may protect against overt autoimmune hypothyroidism: a population-based case-control study

OBJECTIVE

Alcohol consumption is an important protective risk factor for many autoimmune diseases. We wished to study the association between alcohol consumption and autoimmune hypothyroidism.

DESIGN

Population-based, case-control study, 1997-2001, Denmark.

METHODS

Patients with newly diagnosed autoimmune overt hypothyroidism (n=140) were prospectively identified in a population (2 027 208 person-years of observation), and their matched controls with normal thyroid function (n=560) were recruited simultaneously from the same population. Participants gave information on alcohol intake, smoking, previous diseases, education, and family history of hypothyroidism. The association between alcohol intake and development of hypothyroidism was analyzed in conditional regression models.

RESULTS

Hypothyroid cases had reported a lower alcohol consumption than controls (median units of alcohol (12 g) per week: 3 vs 5, P=0.002). In a multivariate regression model, alcohol consumption was associated with a reduction in risk for development of overt autoimmune hypothyroidism. Odds ratios (95% confidence interval) compared with the reference group with a recent (last year) consumption of 1-10 units of alcohol per week were as follows: 0 units/week, 1.98 (1.21-3.33); 11-20 units/week, 0.41 (0.20-0.83); and ≥21 units/week, 0.90 (0.41-2.00). Similar results were found for maximum previous alcohol consumption during a calendar year. No interaction was found with type of alcohol consumed (wine vs beer), sex, or region of inhabitancy.

CONCLUSIONS

Alcohol consumption seems to confer considerable protection against development of overt autoimmune hypothyroidism irrespective of sex and type of alcohol consumed.

Cigarette smoking, alcohol intake, and thyroid cancer risk: a pooled analysis of five prospective studies in the United States

OBJECTIVE

We examined the associations between cigarette smoking, alcohol intake, and thyroid cancer risk in a pooled analysis of five prospective studies.

METHODS

Data from five prospective U.S. studies were standardized and then combined into one aggregate dataset (384,433 men and 361,664 women). Pooled hazard ratios (HR) and 95 % confidence intervals (CI) for thyroid cancer were estimated from mutually adjusted models of cigarette smoking and alcohol intake, which were additionally adjusted for age, sex, education, race, marital status, body mass index, and cohort.

RESULTS

Over follow-up, 1,003 incident thyroid cancer cases (335 men and 668 women) were identified. Compared to never smokers, current smoking was associated with reduced risk of thyroid cancer (HR = 0.68, 95 % CI 0.55-0.85); this association was slightly stronger among non-drinkers (HR = 0.46, 95 % CI 0.29-0.74). No reduction in risk was observed for former, compared to never, smokers. Greater smoking intensity, duration, and pack-years were associated with further reductions in risk among former and current smokers. Alcohol intake was also inversely associated with thyroid cancer risk (≥7 drinks/week versus 0, HR = 0.72, 95 % CI 0.58-0.90, p trend = 0.002). Inverse associations with smoking and alcohol were more pronounced for papillary versus follicular tumors.

CONCLUSION

The results of this pooled analysis suggest that both cigarette smoking and alcohol consumption are associated with reduced risks of papillary thyroid cancer and, possibly, follicular thyroid cancer.

Prevalence of hypothyroidism in nonalcoholic fatty liver disease

BACKGROUND

A possible association between nonalcoholic fatty liver disease (NAFLD) and hypothyroidism has been suggested. The recognized link between hypothyroidism and elements of the metabolic syndrome may explain this association.

AIM

The purpose of this study was to determine the prevalence of hypothyroidism in a cohort of patients with NAFLD and analyze the potential factors associated with hypothyroidism in this patient population.

METHODS

Two hundred forty-six patients with biopsy-proven NAFLD attending hepatology clinics at the Cleveland Clinic between October 2006 and June 2009, and 430 age-, gender-, race- and BMI-matched control subjects seen in the general internal medicine clinic were included. Patients with a clinical diagnosis of hypothyroidism who were on thyroid replacement therapy were considered to be hypothyroid.

RESULTS

Hypothyroidism was more frequent among patients with NAFLD (21% vs. 9.5%; P < 0.01) compared to controls, and was higher in NASH patients than NAFLD patients without NASH (25% vs. 12.8%, P = 0.03). Subjects with hypothyroidism were 2.1 (95% CI 1.1-3.9, P = 0.02) and 3.8 (95% CI 2-6.9, P < 0.001) times more likely to have NAFLD and NASH, respectively. By multivariate analysis, female gender (P < 0.001) and increased BMI (P = 0.03) were associated with hypothyroidism. NAFLD subjects who reported mild alcohol consumption were less likely to have hypothyroidism compared to those who reported complete abstinence (OR 0.37, P = 0.008).

CONCLUSIONS

A higher prevalence of hypothyroidism was demonstrated in patients with NAFLD compared to controls. Among subjects with NALFD, female gender, increased BMI and history of abstinence from alcohol were associated with hypothyroidism. Patients with hypothyroidism were also more likely to have NASH.

Alcohol intake and risk of thyroid cancer in the NIH-AARP Diet and Health Study

Background:

Certain studies suggest that alcohol may reduce the risk of thyroid cancer in women, but the effect in men remains unclear.

Methods:

We analysed the association between alcohol and thyroid cancer in a large (n=490 159) prospective NIH-AARP Diet and Health Study with self-reported beer, wine, and liquor intakes.

Results:

Over 7.5 years of follow-up (median), 170 men and 200 women developed thyroid cancer. Overall, the thyroid cancer risk decreased with greater alcohol consumption (⩾2 drinks per day vs none, relative risk=0.57, 95% CI 0.36–0.89, P-trend=0.01).

Conclusions:

These results suggest a potential protective role for alcohol consumption in thyroid cancer.

Effects of light to moderate alcohol consumption on thyroid volume and thyroid function

OBJECTIVE

To examine a possible relationship between alcohol consumption and thyroid volume and function.

SUBJECTS

A total of 1493 subjects (599 males aged 45-60 years and 894 females aged 35-60 years) with no known thyroid disorders who were participating in the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study.

MEASURES

Daily dietary intakes and alcohol consumption in grams per day were based on five 24-h dietary records. Thyroid volume and structure were measured by ultrasonography. At baseline, TSH and free T4 (FT4) were measured.

RESULTS

Male and female drinkers consumed (mean +/- SD), respectively, 30.6 +/- 23.3 and 14.2 +/- 13.4 g of ethanol per day. There was a decrease in carbohydrate intake with higher alcohol consumption among both male (P = 0.0001) and female drinkers (P = 0.06). Alcohol intake was associated with higher thyroid volume in males and females independently of iodine status. Multivariate odds ratios (ORs, with 95% confidence intervals) of thyroid enlargement (sex-specific 85th percentile values of > or = 20 ml for males, > or = 14 ml for females) in males and females who drank > or = 45 and > or = 20 g/day, respectively, were 2.22 (1.10-4.47) and 2.11 (1.15-3.90) compared with low drinkers, and 11.75 (2.15-64.12) and 2.03 (1.04-3.96) compared with abstainers. ORs were slightly increased when smokers were excluded. Alcohol intake was associated with low FT4 levels in male drinkers independently of TSH.

CONCLUSIONS

An increasing dose-response relationship was found between alcohol intake levels and ORs for thyroid enlargement in both males and females. Alcohol consumption was strongly associated with a higher risk in females.

Alcoolização de nódulo tiroidiano em região endêmica de bócio colóide

A doença nodular tiroidiana é problema clínico comum, principalmente em regiões com carência de iodo. Esse estudo avaliou a eficácia da injeção percutânea de etanol (IPE) no tratamento de nódulos tiroidianos únicos, múltiplos, sólidos, císticos, de diferentes tamanhos com ou sem disfunção glandular, em região endêmica de bócio. Quarenta e dois pacientes com diagnóstico de bócio colóide ou hiperplasia nodular colóide, na punção biópsia aspirativa por agulha fina (PBAAF), foram selecionados para análise após terem sido submetidos a pelo menos duas IPEs. Os nódulos tiroidianos eram múltiplos (sólidos e ou císticos) em 52,4% dos pacientes, únicos e sólidos ou mistos em 35,7% e únicos e císticos em 11,9%. A redução média dos nódulos após injeção de etanol foi de 58,2% para os únicos e 60,8% nos císticos. Nos nódulos múltiplos, avaliou-se a redução de todo o lobo tiroidiano, alcançando 52,4% de redução. Os efeitos colaterais registrados foram decorrentes apenas do desconforto na aplicação. Este estudo indica que a injeção percutânea de etanol (IPE), alcançando reduções médias de volume que variam de 49 a 60%, é método seguro, eficaz e simples para o tratamento de nódulos tiroidianos benignos.

An Investigation of Epidemiologic Factors Associated With Large Nodular Goiter

BACKGROUND

Sporadic nodular goiter is a common problem in the United States and significant compressive symptoms may occur with progression to a critical size.

METHODS

Potential epidemiological variables associated with the development of large unilateral (> or = 50 g) and bilateral (> or = 100 g) nodular goiter were investigated including: age, gender, race, body mass index (BMI), family history of thyroid disease, pregnancy at time of diagnosis, insurance status, and tobacco or alcohol use. Data were obtained from an IRB-approved thyroid database and retrospective chart review of consecutive patients operated on for nodular goiter from 1990 through 2005. A univariate and multivariate analysis of epidemiological variables in patients with "large" versus "small" nodular goiter was completed.

RESULTS

Of the 488 patients operated on for nodular goiter, 113 (23%) were classified as "large," 43 with unilateral (mean 106 +/- 72 g) and 70 with bilateral enlargement (mean 173 +/- 92 g) and 375 (77%) were classified as "small," 179 with unilateral (18 +/- 10 g) and 196 with bilateral (37 +/- 24 g) enlargement. Based on univariate analysis, African-American race, age > or = 40 years, BMI > or = 30 kg/m2, and lack of insurance were associated with an increased risk of large nodular goiter (P < or = 0.001), whereas alcohol use was protective (P = 0.002). A multivariate analysis revealed that African-American race [adjusted odds ratio (adj. OR) 3.3, 95% CI = 2.0-5.4], age > or = 40 years (adj. OR 2.1, 95% CI = 1.2-3.8), and BMI > or = 30 kg/m2 (adj. OR 2.5, 95% CI = 1.5-4.0) were independently associated with large nodular goiter. No significant differences were observed in gender, family history of thyroid disease, pregnancy, or tobacco use (P > 0.1).

CONCLUSIONS

African-American race, obesity, and increasing age are independent risk factors for the development of large nodular goiter. These results may be helpful in determining how best to monitor patients with nodular goiter, with earlier intervention to help prevent progressive enlargement and its sequelae.

Risk factors for thyroid cancer: a prospective cohort study

Given the higher incidence rate of thyroid cancer among women compared to men and evidence that smoking and alcohol consumption may be inversely related to thyroid cancer risk, we examined thyroid cancer risk in association with menstrual, reproductive and hormonal factors, and cigarette and alcohol consumption, in a prospective cohort study of 89,835 Canadian women aged 40-59 at recruitment who were enrolled in the National Breast Screening Study (NBSS). Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths from all causes, respectively, with follow-up ending between 1998 and 2000. Cox proportional hazards models (using age as the time scale) were used to estimate hazard ratios and 95% confidence intervals for the association between each of the potential risk factors and risk of thyroid cancer overall and by the main histologic subtypes. During a mean of 15.9 years of follow-up, we observed 169 incident thyroid cancer cases. There was no evidence of altered overall thyroid cancer risk with any of the menstrual, reproductive, or hormonal factors. There was evidence of a decreased risk of papillary thyroid cancer among women with 5 or more live births (vs. nulliparous). Age at which smoking commenced, duration of smoking, number of cigarettes smoked per day, pack-years of smoking and alcohol consumption were not associated with altered thyroid cancer risk. The present study provides little support for associations with hormonal factors, smoking, or alcohol consumption, but there is a need for additional prospective data.

A population study of the association between thyroid autoantibodies in serum and abnormalities in thyroid function and structure

OBJECTIVE

Patients with autoimmune overt hypothyroidism may present with goitrous Hashimoto's disease or autoimmune atrophic thyroiditis. Little is known about the prevalence of subclinical autoimmune hypothyroidism. The aims of this study were to evaluate the association between thyroid autoantibodies in serum and abnormalities in thyroid function and structure, and to study the thyroid volume in subjects with subclinical autoimmune hypothyroidism.

DESIGN

A population study including 4649 randomly selected subjects.

MEASUREMENTS

Blood tests were used to analyse for thyroid peroxidase autoantibodies (TPO-Ab), thyroglobulin autoantibodies (Tg-Ab), TSH, fT3 and fT4.

RESULTS

Thyroid volume was categorized as small (< 6.6 ml) in 4.7%, normal (6.6-14.9 ml) in 60.4% and large (> 14.9 ml) in 34.9% of participants. Thyroid nodules were found in 29.7%. Serum TSH was low (< 0.4 mIU/l) in 4.7%, normal (0.4-3.6) in 91.0% and high (> 3.6) in 4.3%. The prevalence rate of subclinical goitrous Hashimoto's disease was 0.62% and of subclinical autoimmune atrophic thyroiditis 0.24%. There was a strong association between large volume and autoantibodies, but only in subjects with elevated TSH (P < 0.001). An association between thyroid nodules and TPO-Ab in univariate analyses (P < 0.001) was due to confounding by sex and age (multivariate model, P = 0.23).

CONCLUSION

We identified a subgroup of the population with subclinical goitrous Hashimoto's disease and a smaller subgroup with subclinical autoimmune atrophic thyroiditis. This relationship between small and large thyroid volume in subclinical disease is opposite to that in overt disease, which may suggest that the period between development of a small volume with circulating autoantibodies and overt hypothyroidism is relatively short.

Glutathione S-transferase polymorphisms in thyroid cancer patients

Glutathione S-transferases (GST) are enzymes involved in the metabolism of many carcinogens and mutagens, also acting as important free-radical scavengers. The existence of different genetic polymorphisms in human populations has proven to be a susceptibility factor for different tumours. Nevertheless, as far as we know, for thyroid cancer no study has been conducted until now linking its incidence to genetic susceptibility biomarkers. The present investigation has been conducted to detect the possible association between polymorphism at the GSTM1, GSTT1 and GSTP1 genes and thyroid cancer incidence. Thus, 134 thyroid cancer patients and 116 controls, all from the urban district of Barcelona (Spain), have been included in this study. The results indicate that, according to the calculated odds ratio, the frequencies of the different genotypes found in the group of cancer patients do not significantly differ from those values obtained in the controls. This is true for the overall data as well as for the tumour characterization as follicular and papillar types. In addition, none of the possible combinations of mutant genotypes were shown to be risk factors. Finally, when the sex of the patients, the age of tumour onset, and life-style habits were also taken into account, no influence was observed related to the different genotypes. In conclusion, the results obtained in this study clearly suggest that those susceptibility factors related to the different GST polymorphic enzymes are not a predisposing factor in thyroid cancer disease.