Triglyceride-Glucose Index Predicts Future Atherosclerotic Cardiovascular Diseases: A 16-Year Follow-up in a Prospective, Community-Dwelling Cohort Study

Background@#While the triglyceride-glucose (TyG) index is a measure of insulin resistance, its association with cardiovascular disease (CVD) has not been well elucidated. We evaluated the TyG index for prediction of CVDs in a prospective large communitybased cohort. @*Methods@#Individuals 40 to 70 years old were prospectively followed for a median 15.6 years. The TyG index was calculated as the Ln [fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2]. CVDs included any acute myocardial infarction, coronary artery disease or cerebrovascular disease. We used a Cox proportional hazards model to estimate CVD risks according to quartiles of the TyG index and plotted the receiver operating characteristics curve for the incident CVD. @*Results@#Among 8,511 subjects (age 51.9±8.8 years; 47.5% males), 931 (10.9%) had incident CVDs during the follow-up. After adjustment for age, sex, body mass index, diabetes mellitus, hypertension, total cholesterol, smoking, alcohol, exercise, and C-reactive protein, subjects in the highest TyG quartile had 36% increased risk of incident CVD compared with the lowest TyG quartile (hazard ratio, 1.36; 95% confidence interval, 1.10 to 1.68). Carotid plaque, assessed by ultrasonography was more frequent in subjects in the higher quartile of TyG index (P for trend=0.049 in men and P for trend <0.001 in women). The TyG index had a higher predictive power for CVDs than the homeostasis model assessment of insulin resistance (HOMA-IR) (area under the curve, 0.578 for TyG and 0.543 for HOMA-IR). Adding TyG index on diabetes or hypertension alone gave sounder predictability for CVDs. @*Conclusion@#The TyG index is independently associated with future CVDs in 16 years of follow-up in large, prospective Korean cohort.

Protocol for a Korean Multicenter Prospective Cohort Study of Active Surveillance or Surgery (KoMPASS) in Papillary Thyroid Microcarcinoma

Background@#A Korean Multicenter Prospective cohort study of Active Surveillance or Surgery (KoMPASS) for papillary thyroid microcarcinomas (PTMCs) has been initiated. The aim is to compare clinical outcomes between active surveillance (AS) and an immediate lobectomy for low-risk PTMCs. We here outline the detailed protocol for this study. @*Methods@#Adult patients with a cytopathologically confirmed PTMC sized 6.0 to 10.0 mm by ultrasound (US) will be included. Patients will be excluded if they have a suspicious extra-thyroidal extension or metastasis of a PTMC or multiple thyroid nodules or other thyroid diseases which require a total thyroidectomy. Printed material describing the prognosis of PTMCs, and the pros and cons of each management option, will be provided to eligible patients to select their preferred intervention. For the AS group, thyroid US, thyroid function, and quality of life (QoL) parameters will be monitored every 6 months during the first year, and then annually thereafter. Disease progression will be defined as a ≥3 mm increase in maximal diameter of a PTMC, or the development of new thyroid cancers or metastases. If progression is detected, patients should undergo appropriate surgery. For the lobectomy group, a lobectomy with prophylactic central neck dissection will be done within 6 months. After initial surgery, thyroid US, thyroid function, serum thyroglobulin (Tg), anti-Tg antibody, and QoL parameters will be monitored every 6 months during the first year and annually thereafter. Disease progression will be defined in these cases as the development of new thyroid cancers or metastases. @*Conclusion@#KoMPASS findings will help to confirm the role of AS, and develop individualized management strategies, for low-risk PTMCs.

Association between Thyroid Function and Heart Rate Monitored by Wearable Devices in Patients with Hypothyroidism

Background@#Heart rate (HR) monitored by a wearable device (WD) has demonstrated its clinical feasibility for thyrotoxicosis subjects. However, the association of HR monitored by wearables with hypothyroidism has not been examined. We assessed the association between serum thyroid hormone concentration and three WD-HR parameters in hypothyroid subjects. @*Methods@#Forty-four subjects scheduled for radioactive iodine therapy (RAI Tx) after thyroid cancer surgery were included. Thirty subjects were prepared for RAI Tx by thyroid hormone withdrawal (hypothyroidism group) and 14 subjects by recombinant human thyrotropin (control group). Three WD-HR parameters were calculated from the HR data collected during rest, during sleep, and from 2:00 AM to 6:00 AM, respectively. We analyzed the changes in conventionally measured resting HR (On-site rHR) and WDHR parameters relative to thyroid hormone levels. @*Results@#Serum free thyroxine (T4) levels, On-site rHR, and WD-HR parameters were lower in the hypothyroid group than in the control group at the time of RAI Tx. WD-HR parameters also reflected minute changes in free T4 levels. A decrease in On-site rHR and WD-HR parameters by one standard deviation (On-site rHR, approximately 12 bpm; WD-HR parameters, approximately 8 bpm) was associated with a 0.2 ng/dL decrease in free T4 levels (P<0.01) and a 2-fold increase of the odds ratio of hypothyroidism (P<0.01). WD-HR parameters displayed a better goodness-of-fit measure (lower quasi-information criterion value) than On-site rHR in predicting the hypothyroidism. @*Conclusion@#This study identified WD-HR parameters as informative and easy-to-measure biomarkers to predict hypothyroidism.

Protocol for a Korean Multicenter Prospective Cohort Study of Active Surveillance or Surgery (KoMPASS) in Papillary Thyroid Microcarcinoma

Background@#A Korean Multicenter Prospective cohort study of Active Surveillance or Surgery (KoMPASS) for papillary thyroid microcarcinomas (PTMCs) has been initiated. The aim is to compare clinical outcomes between active surveillance (AS) and an immediate lobectomy for low-risk PTMCs. We here outline the detailed protocol for this study. @*Methods@#Adult patients with a cytopathologically confirmed PTMC sized 6.0 to 10.0 mm by ultrasound (US) will be included. Patients will be excluded if they have a suspicious extra-thyroidal extension or metastasis of a PTMC or multiple thyroid nodules or other thyroid diseases which require a total thyroidectomy. Printed material describing the prognosis of PTMCs, and the pros and cons of each management option, will be provided to eligible patients to select their preferred intervention. For the AS group, thyroid US, thyroid function, and quality of life (QoL) parameters will be monitored every 6 months during the first year, and then annually thereafter. Disease progression will be defined as a ≥3 mm increase in maximal diameter of a PTMC, or the development of new thyroid cancers or metastases. If progression is detected, patients should undergo appropriate surgery. For the lobectomy group, a lobectomy with prophylactic central neck dissection will be done within 6 months. After initial surgery, thyroid US, thyroid function, serum thyroglobulin (Tg), anti-Tg antibody, and QoL parameters will be monitored every 6 months during the first year and annually thereafter. Disease progression will be defined in these cases as the development of new thyroid cancers or metastases. @*Conclusion@#KoMPASS findings will help to confirm the role of AS, and develop individualized management strategies, for low-risk PTMCs.

Changes of Nodular Size and Its Risk Factors in Iodine-Sufficient Area: a Retrospective Cohort Analysis of 7753 Thyroid Nodules

Background and Objectives@#Iodine is known to be an important factor in the occurrence of goiter, and South Korea is a region with sufficient iodine supplementation. In this regard, we checked the size change of thyroid nodules found by health check-up in Koreans and examined which risk factors influence the size change. @*Materials and Methods@#A total 7753 subjects who underwent thyroid sonography two or more times were included. We defined that there was a change in the size of the nodule when the difference in diameter identified in the last ultrasound was more than 3 mm. @*Results@#Thyroid nodules were decreased in 895 subjects (11.5%) and increased in 1041 subjects (13.5%). The rate of increased nodule was on an increasing trend according to the duration (annual percent change 2.6%, p＜0.001). In contrast, the rate of decreased nodule was unchanged. Predictive factors related to decrease of the nodule size were young age, male sex, larger initial nodule size and thyroiditis. Similarly, young age, larger initial nodule size and diffuse parenchymal abnormality were significant predictive factors for increased nodules. However, diffuse parenchymal abnormality was not a predictive factor when we analyzed only thyroid nodules larger than 1 cm. @*Conclusion@#In our study, 11.5-13.5% of benign thyroid nodules were increased or decreased during median 27 months of follow-up in iodine sufficient condition. Young age, larger initial size and diffuse parenchymal abnormality were common predictive factor affecting both the increase and decrease of thyroid nodules.

Subclinical Hypothyroidism Affects the Long-Term Outcomes of Patients Who Undergo Coronary Artery Bypass Grafting Surgery but Not Heart Valve Surgery

Background@#The aim of this study was to determine the associations between subclinical hypothyroidism (SCH) and long-term cardiovascular outcomes after coronary artery bypass grafting (CABG) or heart valve surgery (HVS). @*Methods@#We retrospectively reviewed and compared all-cause mortality, cardiovascular mortality, and cardiovascular events in 461 patients who underwent CABG and 104 patients who underwent HVS. @*Results@#During a mean±standard deviation follow-up duration of 7.6±3.8 years, there were 187 all-cause deaths, 97 cardiovascular deaths, 127 major adverse cardiovascular events (MACE), 11 myocardial infarctions, one unstable angina, 70 strokes, 30 hospitalizations due to heart failure, 101 atrial fibrillation, and 33 coronary revascularizations. The incidence of all-cause mortality after CABG was significantly higher in patients with SCH (n=36, 55.4%) than in euthyroid patients (n=120, 30.3%), with a hazard ratio of 1.70 (95% confidence interval, 1.10 to 2.63; P=0.018) after adjustment for age, sex, current smoking status, body mass index, underlying diseases, left ventricular dysfunction, and emergency operation. Interestingly, low total triiodothyronine (T3) levels in euthyroid patients who underwent CABG were significantly associated with increased risks of all-cause mortality, cardiovascular mortality, and MACE, but those associations were not observed in HVS patients. Both free thyroxine and thyroid-stimulating hormone levels in euthyroid patients were not related with any cardiovascular outcomes in either the CABG or HVS group. @*Conclusion@#SCH or low total T3 might be associated with a poor prognosis after CABG, but not after HVS, implying that preoperative thyroid hormonal status may be important in ischemic heart disease patients.

Digital Medicine in Thyroidology: A New Era of Managing Thyroid Disease

Digital medicine has the capacity to affect all aspects of medicine, including disease prediction, prevention, diagnosis, treatment, and post-treatment management. In the field of thyroidology, researchers are also investigating potential applications of digital technology for the thyroid disease. Recent studies using artificial intelligence (AI)/machine learning (ML) have reported reasonable performance for the classification of thyroid nodules based on ultrasonographic (US) images. AI/ML-based methods have also shown good diagnostic accuracy for distinguishing between benign and malignant thyroid lesions based on cytopathologic findings. Assistance from AI/ML methods could overcome the limitations of conventional thyroid US and fine-needle aspiration cytology. A web-based database has been developed for thyroid cancer care. In addition to its role as a nationwide registry of thyroid cancer, it is expected to serve as a clinical platform to facilitate better thyroid cancer care and as a research platform providing comprehensive disease-specific big data. Evidence has been found that biosignal monitoring with wearable devices may predict thyroid dysfunction. This real-world thyroid function monitoring could aid in the management and early detection of thyroid dysfunction. In the thyroidology field, research involving the range of digital medicine technologies and their clinical applications is expected to be even more active in the future.

Corrigendum to “Evaluation of Potency on Diphtheria and Tetanus Toxoid for Adult Vaccines by In Vivo Toxin Neutralization Assay Using National Reference Standards”Osong Public Health Res Perspect 2018;9(5):278–82

The authors wanted to include the statement along with the existing sentence in the Acknowledgments section.

Evaluation of Potency on Diphtheria and Tetanus Toxoid for Adult Vaccines by In Vivo Toxin Neutralization Assay Using National Reference Standards

OBJECTIVES: Vaccinations against diphtheria and tetanus are essential in providing immunity against these bacterial infections. The potency of diphtheria and tetanus toxoid vaccines can be measured using the in vivo toxin neutralization assay. The limit of potency of this assay was determined only for children. Therefore, we assessed the potency of adult vaccines using this assay to identify the feasibility of limit for adult vaccines. METHODS: Fifteen lots of tetanus-reduced diphtheria and tetanus-diphtheria-acellular pertussis vaccines were used. In vivo toxin neutralization and lethal challenge assays were conducted on each vaccine to calculate the potencies of the toxoids. National reference standards for toxins and antitoxins were used for in vivo toxin neutralization assay. RESULTS: All 15 lots satisfied the limits of potency for lethal challenge assay. The potency of diphtheria and tetanus toxoids exceeded 1 and 8 units/mL, respectively, for in vivo toxin neutralization assay. CONCLUSION: Although additional studies are required for new assays and limits, the current level of potency for adult vaccines as determined by in vivo toxin neutralization assay, was demonstrated in this study. Such efforts to improve assays are expected to promote the development of diphtheria and tetanus vaccines for adults and to contribute to vaccine self-sufficiency.

Corrigendum: Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

No abstract available.

Diagnosis and treatment of low-risk papillary thyroid microcarcinoma

Recent guidelines for the treatment of thyroid nodules and differentiated thyroid cancer include active surveillance as an alternative option for the treatment of low-risk papillary thyroid microcarcinoma (PTMC). PTMC is defined as having a tumor diameter of ≤1 cm, and low-risk PTMC is defined as PTMC without currently known risk factors (e.g., metastases, local invasion, or cytologic evidence of aggressive disease). Some researchers have suggested that active surveillance can be the first-line treatment of low risk PTMC based on reports showing that the oncological outcomes of active surveillance and immediate surgery were similarly excellent and that immediate surgery can occasionally be accompanied by surgical complications. Nonetheless, many concerns still exist about the full implementation of active surveillance in current clinical practice because the biology of PTMC still has not been fully elucidated and there is little evidence regarding the long-term prognosis of active surveillance. In this review, we discuss the current concept of low-risk PTMC and its treatment modalities, comparing immediate surgery and active surveillance in terms of clinical applications, prognosis, adverse effects, quality of life, and medical costs. This review aims to enable healthcare providers to provide patients with well-balanced information about immediate surgery and active surveillance for the treatment of low-risk PTMC.

Diagnosis and treatment of low-risk papillary thyroid microcarcinoma

Recent guidelines for the treatment of thyroid nodules and differentiated thyroid cancer include active surveillance as an alternative option for the treatment of low-risk papillary thyroid microcarcinoma (PTMC). PTMC is defined as having a tumor diameter of ≤1 cm, and low-risk PTMC is defined as PTMC without currently known risk factors (e.g., metastases, local invasion, or cytologic evidence of aggressive disease). Some researchers have suggested that active surveillance can be the first-line treatment of low risk PTMC based on reports showing that the oncological outcomes of active surveillance and immediate surgery were similarly excellent and that immediate surgery can occasionally be accompanied by surgical complications. Nonetheless, many concerns still exist about the full implementation of active surveillance in current clinical practice because the biology of PTMC still has not been fully elucidated and there is little evidence regarding the long-term prognosis of active surveillance. In this review, we discuss the current concept of low-risk PTMC and its treatment modalities, comparing immediate surgery and active surveillance in terms of clinical applications, prognosis, adverse effects, quality of life, and medical costs. This review aims to enable healthcare providers to provide patients with well-balanced information about immediate surgery and active surveillance for the treatment of low-risk PTMC.

Validity and Reliability of the Korean Version of the Hyperthyroidism Symptom Scale

BACKGROUND: Thyrotoxicosis is a common disease resulting from an excess of thyroid hormones, which affects many organ systems. The clinical symptoms and signs are relatively nonspecific and can vary depending on age, sex, comorbidities, and the duration and cause of the disease. Several symptom rating scales have been developed in an attempt to assess these symptoms objectively and have been applied to diagnosis or to evaluation of the response to treatment. The aim of this study was to assess the reliability and validity of the Korean version of the hyperthyroidism symptom scale (K-HSS). METHODS: Twenty-eight thyrotoxic patients and 10 healthy subjects completed the K-HSS at baseline and after follow-up at Seoul National University Bundang Hospital. The correlation between K-HSS scores and thyroid function was analyzed. K-HSS scores were compared between baseline and follow-up in patient and control groups. Cronbach's α coefficient was calculated to demonstrate the internal consistency of K-HSS. RESULTS: The mean age of the participants was 34.7±9.8 years and 13 (34.2%) were men. K-HSS scores demonstrated a significant positive correlation with serum free thyroxine concentration and decreased significantly with improved thyroid function. K-HSS scores were highest in subclinically thyrotoxic subjects, lower in patients who were euthyroid after treatment, and lowest in the control group at follow-up, but these differences were not significant. Cronbach's α coefficient for the K-HSS was 0.86. CONCLUSION: The K-HSS is a reliable and valid instrument for evaluating symptoms of thyrotoxicosis in Korean patients.

Prevalence of thyroid nodules and their associated clinical parameters: a large-scale, multicenter-based health checkup study

BACKGROUND/AIMS: We evaluated the prevalence and characteristics of thyroid nodules detected by thyroid ultrasound (US) at health checkups and the associated clinical parameters. METHODS: A total of 72,319 subjects who underwent thyroid US at three health checkup centers in Korea from January 2004 to December 2010 were included in this study. The correlations between the presence of thyroid nodules and other clinical parameters were analyzed. RESULTS: The prevalence of thyroid nodules and cysts was 34.2% (n = 24,757). Thyroid nodules were more prevalent in women and older age groups. Among the subjects with thyroid nodules with size information (n = 24,686), 18,833 (76.3%) had nodules measuring ≤ 1.0 cm. Women and older age groups showed higher proportion of larger nodules. Percentage of women, age, body mass index (BMI), waist circumference, body fat composition, blood pressure, and the level of fasting glucose, total cholesterol, and low density lipoprotein cholesterol were higher in the subjects with thyroid nodules compared to those without nodules. The prevalence of metabolic syndrome and overt/subclinical thyrotoxic state was higher in the subjects with thyroid nodules. In the multivariable logistic regression analysis, women, age, BMI, metabolic syndrome, and thyrotoxicosis were independently associated with the presence of thyroid nodules. CONCLUSIONS: The high prevalence of thyroid nodules in people who underwent thyroid US at a health checkup suggests that increased detection of thyroid nodules resulted in an increased prevalence in the general population. However, metabolic disturbances may also have contributed to the increase in thyroid nodule prevalence in Korea.

Star-Shaped Intense Uptake of ¹³¹I on Whole Body Scans Can Reflect Good Therapeutic Effects of Low-Dose Radioactive Iodine Treatment of 1.1 GBq

BACKGROUND: After initial radioactive iodine (RAI) treatment in differentiated thyroid cancer patients, we sometimes observe a star-shaped region of intense uptake of 131I on whole body scans (WBSs), called a ‘star artifact.’ We evaluated the clinical implications of star artifacts on the success rate of remnant ablation and long-term prognosis. METHODS: Total 636 patients who received 131I dose of 1.1 GBq for the initial RAI therapy and who did not show distant metastasis at the time of diagnosis were retrospectively evaluated. A negative second WBS was used for evaluating the ablation efficacy of the RAI therapy. Among them, 235 patients (36.9%) showed a star artifact on their first WBS. RESULTS: In patients with first stimulated thyroglobulin (sTg) levels ≤2 ng/mL, patients with star artifacts had a higher rate of negative second WBS compared with those without star artifacts (77.8% vs. 63.9%, P=0.044), and showed significantly higher recurrence-free survival (P=0.043) during the median 8.0 years (range, 1.0 to 10.0) of follow-up. The 5- and 10-year recurrence rates (5YRR, 10YRR) were also significantly lower in patients with star artifacts compared with those without (0% vs. 4.9%, respectively, P=0.006 for 5YRR; 0% vs. 6.4%, respectively, P=0.005 for 10YRR). However, ablation success rate or recurrence-free survival was not different among patients whose first sTg levels >2 ng/mL regardless of star artifacts. CONCLUSION: Therefore, star artifacts at initial RAI therapy imply a good ablation efficacy or a favorable long-term prognosis in patients with sTg levels ≤2 ng/mL.

Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

BACKGROUND: The ongoing Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) aims to observe the natural course of papillary thyroid microcarcinoma (PTMC), develop a protocol for active surveillance (AS), and compare the long-term prognosis, quality of life, and medical costs between the AS and immediate surgery groups. METHODS: This multicenter prospective cohort study of PTMC started in June 2016. The inclusion criteria were suspicious of malignancy or malignancy based on fine needle aspiration or core needle biopsy, age of ≥18 years, and a maximum diameter of ≤1 cm. If there was no major organ involvement, no lymph node/distant metastasis, and no variants with poor prognosis, the patients were explained of the pros and cons of immediate surgery and AS before selecting AS or immediate surgery. Follow-up visits (physical examination, ultrasonography, thyroid function, and questionnaires) are scheduled every 6 months during the first 2 years, and then every 1 year thereafter. Progression was defined as a maximum diameter increase of ≥3, ≥2 mm in two dimensions, suspected organ involvement, or lymph node/distant metastasis. RESULTS: Among 439 enrolled patients, 290 patients (66.1%) chose AS and 149 patients (33.9%) chose immediate surgery. The median follow-up was 6.7 months (range, 0.2 to 11.9). The immediate surgery group had a larger maximum tumor diameter, compared to the AS group (7.1±1.9 mm vs. 6.6±2.0 mm, respectively; P=0.014). CONCLUSION: The results will be useful for developing an appropriate PTMC treatment policy based on its natural course and risk factors for progression.

Utility of Quantitative Parameters from Single-Photon Emission Computed Tomography/Computed Tomography in Patients with Destructive Thyroiditis

OBJECTIVE: Quantitative parameters from Tc-99m pertechnetate single-photon emission computed tomography/computed tomography (SPECT/CT) are emerging as novel diagnostic markers for functional thyroid diseases. We intended to assess the utility of SPECT/CT parameters in patients with destructive thyroiditis. MATERIALS AND METHODS: Thirty-five destructive thyroiditis patients (7 males and 28 females; mean age, 47.3 ± 13.0 years) and 20 euthyroid patients (6 males and 14 females; mean age, 45.0 ± 14.8 years) who underwent Tc-99m pertechnetate quantitative SPECT/CT were retrospectively enrolled. Quantitative parameters from the SPECT/CT (%uptake, standardized uptake value [SUV], thyroid volume, and functional thyroid mass [SUVmean × thyroid volume]) and thyroid hormone levels were investigated to assess correlations and predict the prognosis for destructive thyroiditis. The occurrence of hypothyroidism was the outcome for prognosis. RESULTS: All the SPECT/CT quantitative parameters were significantly lower in the 35 destructive thyroiditis patients compared to the 20 euthyroid patients using the same SPECT/CT scanner and protocol (p < 0.001 for all parameters). T3 and free T4 did not correlate with any SPECT/CT parameters, but thyroid-stimulating hormone (TSH) significantly correlated with %uptake (p = 0.004), SUVmean (p < 0.001), SUVmax (p = 0.002), and functional thyroid mass (p < 0.001). Of the 35 destructive thyroiditis patients, 16 progressed to hypothyroidism. On univariate and multivariate analyses, only T3 levels were associated with the later occurrence of hypothyroidism (p = 0.002, exp(β) = 1.022, 95% confidence interval: 1.008 – 1.035). CONCLUSION: Novel quantitative SPECT/CT parameters could discriminate patients with destructive thyroiditis from euthyroid patients, suggesting the robustness of the quantitative SPECT/CT approach. However, disease progression of destructive thyroiditis could not be predicted using the parameters, as these only correlated with TSH, but not with T3, the sole predictor of the later occurrence of hypothyroidism.

Novel Application of Quantitative Single-Photon Emission Computed Tomography/Computed Tomography to Predict Early Response to Methimazole in Graves' Disease

OBJECTIVE: Since Graves' disease (GD) is resistant to antithyroid drugs (ATDs), an accurate quantitative thyroid function measurement is required for the prediction of early responses to ATD. Quantitative parameters derived from the novel technology, single-photon emission computed tomography/computed tomography (SPECT/CT), were investigated for the prediction of achievement of euthyroidism after methimazole (MMI) treatment in GD. MATERIALS AND METHODS: A total of 36 GD patients (10 males, 26 females; mean age, 45.3 ± 13.8 years) were enrolled for this study, from April 2015 to January 2016. They underwent quantitative thyroid SPECT/CT 20 minutes post-injection of (99m)Tc-pertechnetate (5 mCi). Association between the time to biochemical euthyroidism after MMI treatment and %uptake, standardized uptake value (SUV), functional thyroid mass (SUVmean × thyroid volume) from the SPECT/CT, and clinical/biochemical variables, were investigated. RESULTS: GD patients had a significantly greater %uptake (6.9 ± 6.4%) than historical control euthyroid patients (n = 20, 0.8 ± 0.5%, p < 0.001) from the same quantitative SPECT/CT protocol. Euthyroidism was achieved in 14 patients at 156 ± 62 days post-MMI treatment, but 22 patients had still not achieved euthyroidism by the last follow-up time-point (208 ± 80 days). In the univariate Cox regression analysis, the initial MMI dose (p = 0.014), %uptake (p = 0.015), and functional thyroid mass (p = 0.016) were significant predictors of euthyroidism in response to MMI treatment. However, only %uptake remained significant in a multivariate Cox regression analysis (p = 0.034). A %uptake cutoff of 5.0% dichotomized the faster responding versus the slower responding GD patients (p = 0.006). CONCLUSION: A novel parameter of thyroid %uptake from quantitative SPECT/CT is a predictive indicator of an early response to MMI in GD patients.

Application of the 2013 American College of Cardiology/American Heart Association Cholesterol Guideline to the Korean National Health and Nutrition Examination Surveys from 1998 to 2012

BACKGROUND: The 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline for the treatment of blood cholesterol recommends statin therapy for individuals at high risk of atherosclerotic cardiovascular disease (ASCVD). The aim of this study was to investigate serial trends in the percentages of Korean adults considered eligible for statin therapy according to the new ACC/AHA cholesterol guideline. METHODS: Data from the Korean National Health and Nutrition Examination Survey (KNHANES) I (1998, n=7,698), II (2001, n=5,654), III (2005, n=5,269), IV (2007 to 2009, n=15,727), and V (2010 to 2012, n=16,304), which used a stratified, multistage, probability sampling design, were used as representative of the entire Korean population. RESULTS: The percentage of adults eligible for statin therapy according to the ACC/AHA cholesterol guideline increased with time: 17.0%, 19.0%, 20.8%, 20.2%, and 22.0% in KNHANES I, II, III, IV, and V, respectively (P=0.022). The prevalence of ASCVD was 1.4% in KNHANES I and increased to 3.3% in KNHANES V. The percentage of diabetic patients aged 40 to 75 years with a low density lipoprotein cholesterol levels of 70 to 189 mg/dL increased from 4.8% in KNHANES I to 6.1% in KNHANES V. People with an estimated 10-year ASCVD risk ≥7.5% and aged 40 to 75 years accounted for the largest percentage among the four statin benefit groups: 9.1% in KNHANES I and 11.0% in KNHANES V. CONCLUSION: Application of the 2013 ACC/AHA guideline has found that the percentage of Korean adults in the statin benefit groups has increased over the past 15 years.

Endocrine Risk Factors for Cognitive Impairment

Cognitive impairment, including Alzheimer's disease and other kinds of dementia, is a major health problem in older adults worldwide. Although numerous investigators have attempted to develop effective treatment modalities or drugs, there is no reasonably efficacious strategy for preventing or recovering from cognitive impairment. Therefore, modifiable risk factors for cognitive impairment have received attention, and the growing literature of metabolic risk factors for cognitive impairment has expanded from epidemiology to molecular pathogenesis and therapeutic management. This review focuses on the epidemiological evidence for the association between cognitive impairment and several endocrine risk factors, including insulin resistance, dyslipidemia, thyroid dysfunction, vitamin D deficiency, and subclinical atherosclerosis. Researches suggesting possible mechanisms for this association are reviewed. The research investigating modifiable endocrine risk factors for cognitive impairment provides clues for understanding the pathogenesis of cognitive impairment and developing novel treatment modalities. However, so far, interventional studies investigating the beneficial effect of the "modification" of these "modifiable risk factors" on cognitive impairment have reported variable results. Therefore, well-designed, randomized prospective interventional studies are needed.