In recent decades, attention has been directed toward the effects of bisphenol A (BPA) on human health. BPA has estrogenic activity and is regarded as a representative endocrine disruptor. In addition, mounting evidence indicates that BPA can disrupt thyroid hormone and its action. This review examined human epidemiological studies to investigate the association between BPA exposure and thyroid hormone levels, and analyzed in vivo and in vitro experiments to identify the causal relationship and its mechanism of action. BPA is involved in thyroid hormone action not only as a thyroid hormone receptor antagonist, but also through several other mechanisms. Since the use of bisphenols other than BPA has recently increased, we also reviewed the effects of other bisphenols on thyroid hormone action.

Most people are now familiar with the concepts of big data, deep learning, machine learning, and artificial intelligence (AI) and have a vague expectation that AI using medical big data can be used to improve the quality of medical care. However, the expectation that big data could change the field of medicine is inconsistent with the current reality. The clinical meaningfulness of the results of research using medical big data needs to be examined. Medical staff needs to be clear about the purpose of AI that utilizes medical big data and to focus on the quality of this data, rather than the quantity. Further, medical professionals should understand the necessary precautions for using medical big data, as well as its advantages. No doubt that someday, medical big data will play an essential role in healthcare; however, at present, it seems too early to actively use it in clinical practice. The field continues to work toward developing medical big data and making it appropriate for healthcare. Researchers should continue to engage in empirical research to ensure that appropriate processes are in place to empirically evaluate the results of its use in healthcare.

Primary aldosteronism (PA) results from excess production of mineralocorticoid hormone aldosterone by the adrenal cortex. It is normally caused either by unilateral aldosterone-producing adenoma (APA) or by bilateral aldosterone excess as a result of bilateral adrenal hyperplasia. PA is the most common cause of secondary hypertension and associated morbidity and mortality. While most cases of PA are sporadic, an important insight into this debilitating disease has been derived through investigating the familial forms of the disease that affect only a minor fraction of PA patients. The advent of gene expression profiling has shed light on the genes and intracellular signaling pathways that may play a role in the pathogenesis of these tumors. The genetic basis for several forms of familial PA has been uncovered in recent years although the list is likely to expand. Recently, the work from several laboratories provided evidence for the involvement of mammalian target of rapamycin pathway and inflammatory cytokines in APAs; however, their mechanism of action in tumor development and pathophysiology remains to be understood.

Background: Impairment of quality of life (QOL) is a key clinical characteristic of patients with end-stage renal disease (ESRD), and can be especially severe in the presence of secondary hyperparathyroidism (SHPT). Despite the proven success of parathyroidectomy (PTX) in controlling biochemical parameters in patients with severe SHPT, evidence is lacking regarding the effects of PTX on various clinical outcomes, including QOL.
Methods: Twenty ESRD patients on maintenance hemodialysis with SHPT who underwent subtotal PTX were included in an observational longitudinal study. All studied patients underwent history-taking, clinical examinations, and laboratory investigations, including a complete blood count and measurements of serum calcium, phosphorus, magnesium, parathyroid hormone (PTH), and albumin levels preoperatively and at 3 months postoperatively. QOL was assessed before surgery and at 3 months after surgery using the Kidney Disease Quality of Life 36-Item Short-Form instrument.
Results: After PTX, significant decreases in serum PTH and phosphorus levels were observed, as well as a significant increase in serum magnesium levels. Significant weight gain and improvements of QOL were also detected postoperatively.
Conclusion: Subtotal PTX seems to be an efficient alternative to medical management in uncontrolled cases of SHPT, as it is capable of controlling the biochemical derangements that occur in hyperparathyroidism. Furthermore, PTX had a beneficial effect on clinical outcomes, as shown by weight gain and improvements in all QOL scales.

Background: The modified Ferriman-Gallwey (mFG) score is the gold standard for the clinical evaluation of hirsutism. However, racial variations in terminal hair growth limit this tool. This study aimed to determine the mFG cut-off score among Filipino women and its association with biochemical hyperandrogenism.
Methods: A total of 128 Filipino women were included in this prospective cross-sectional study and were divided into two groups: a polycystic ovary syndrome (PCOS) group (n=28) and a non-PCOS group (n=100). The participants underwent mFG score determination, ovarian ultrasound conducted by a single sonographer, and hormone testing. The mFG cut-off score was determined based on the 95th percentile of the non-PCOS group. Logistic regression was used to analyze the relationship between mFG score and biochemical hyperandrogenism.
Results: Although the mFG score was generally low in both the PCOS and non-PCOS groups, the former exhibited a higher mean score than the latter (4.3±3.0 vs. 2.0±2.2, P<0.001). Normal values for the total mFG score ranged from 0 to 7. Using a cut-off score of 7, a higher proportion of hirsute women (mFG score ≥7) was observed in the PCOS group versus the non-PCOS group (17.9% vs. 5.0%, P=0.025). Elevated calculated free testosterone (FT) was also found to be significantly associated with hirsutism (odds ratio, 6.2; 95% confidence interval, 1.2 to 32.4 pmol/L; P=0.030).
Conclusion: A score of 7 and above constitutes hirsutism in this population of Filipino women. Hirsute women are more likely than non-hirsute women to have elevated calculated FT.

Background: Conflicting results have been reported on the efficacy of insulin degludec/insulin aspart (IDegAsp) compared to basal insulin in type 2 diabetes. We investigated the effects of changing basal insulin to IDegAsp on glycemic control and sought to identify factors related to those effects.
Methods: In this retrospective study of patients from three referral hospitals, patients with type 2 diabetes using basal insulin with hemoglobin A1c (HbA1c) levels less than 11.0% were enrolled. Basal insulin was replaced with IDegAsp, and data were analyzed from 3 months before to 3 months after the replacement.
Results: Eighty patients were recruited (52.5% male; mean age, 67.0±9.8 years; mean duration of diabetes, 18.9±8.5 years; mean HbA1c, 8.7%±1.0%). HbA1c levels increased during 3 months of basal insulin use, but significantly decreased after changing to IDegAsp (8.28%±1.10%, P=0.0001). The reduction was significant at 6 months in 35 patients whose longer-term data were available. Patients with a measured fasting plasma glucose (m-FPG) lower than their predicted FPG (p-FPG) by regression from HbA1c showed a significant HbA1c reduction caused by the change to IDegAsp, even without a significantly increased insulin dose. However, patients whose m-FPG was higher than their p-FPG did not experience a significant HbA1c reduction, despite a significantly increased insulin dose. Furthermore, the HbA1c reduction caused by IDegAsp was significant in patients with low fasting C-peptide levels and high insulin doses.
Conclusion: We observed a significant glucose-lowering effect by replacing basal insulin with IDegAsp, especially in patients with a lower m-FPG than p-FPG.

Background: The aim of this study was to determine whether there is a positive correlation between gamma-glutamyltransferase (GGT) levels and the prevalence of metabolic syndrome and whether GGT can be used as an easily checkable metabolic index using data from the large-scale Korean Genome and Epidemiology Study (KoGES).
Methods: We obtained data of 211,725 participants of the KoGES. The collected data included age, sex, height, weight, waist circumference, and various biochemical characteristics, including serum GGT levels. The data of study participants who ingested more than 40 g/day of alcohol and who were diagnosed with metabolic syndrome at baseline was excluded. We analyzed the prevalence of metabolic syndrome according to GGT quartiles in both genders.
Results: The GGT level was significantly higher in subjects with metabolic syndrome compared to normal subjects (37.92±48.20 mg/dL vs. 25.62±33.56 mg/dL). The prevalence of metabolic syndrome showed a stepwise increase with GGT quartiles in both male and female subjects. Compared to the lowest GGT quartile, the odds ratio was 1.534 (95% confidence interval [CI], 1.432 to 1.643), 1.939 (95% CI, 1.811 to 2.076), and 2.754 (95% CI, 2.572 to 2.948) in men and 1.155 (95% CI, 1.094 to 1.218), 1.528 (95% CI, 1.451 to 1.609), and 2.022 (95% CI, 1.921 to 2.218) in women with increasing GGT quartile. The cutoff value of GGT predicting risk of metabolic syndrome was 27 IU/L in men and 17 IU/L in women.
Conclusion: We suggested that GGT could be an easily checkable marker for the prediction of metabolic syndrome.

Background: To evaluate the changes in cardiovascular risk markers including pulse wave velocity (PWV), microalbuminuria, inflammatory cytokines, and adhesion molecules after treatment with beraprost sodium (BPS) in patients with diabetic nephropathy
Methods: This was a multicenter, prospective, randomized, double-blind, placebo-controlled trial. Type 2 diabetes mellitus patients with microalbuminuria were included. The primary endpoints were changes in microalbuminuria in spot urine and PWV after BPS or placebo (PCB) treatment for 24 weeks. The secondary endpoints were changes in clinical and metabolic parameters.
Results: A total of 52 patients completed the 24-week trial. Changes in PWV were not different significantly in the BPS and PCB groups (right, P=0.16; left, P=0.11). Changes in microalbuminuria were 14.2±157.0 and 34.5±146.6 (μg/mg Cr) in the BPS and PCB groups, respectively (P=0.63). Subgroup analysis in the high blood pressure (BP) group (baseline systolic BP >120 mm Hg and diastolic BP >80 mm Hg), showed that microalbuminuria decreased by -47.6 in the BPS group compared with an increase by 116.4 (μg/mg Cr) in the PCB group (P=0.04). Also, in the large waist circumference group (>95 cm), microalbuminuria decreased significantly in the BPS group (P=0.04).
Conclusion: Short-term treatment of BPS for patients with diabetic nephropathy did not show significant improvement in various cardiovascular risk factors. However, BPS significantly decreased microalbuminuria in study subjects with higher cardiovascular risk such as high BP or large waist circumference.

Background: Metabolically healthy obese (MHO) is regarded as a transient concept. We examined the effect of the dynamic change of metabolic health status on the incidence of type 2 diabetes mellitus (T2DM) both in obese and normal weight individuals.
Methods: We analyzed 3,479,514 metabolically healthy subjects aged over 20 years from the Korean National Health Screening Program, who underwent health examination between 2009 and 2010, with a follow-up after 4 years. The relative risk for T2DM incidence until the December 2017 was compared among the four groups: stable metabolically healthy normal weight (MHNW), unstable MHNW, stable MHO, and unstable MHO.
Results: During the 4 years, 11.1% of subjects in the MHNW group, and 31.5% in the MHO group converted to a metabolically unhealthy phenotype. In the multivariate adjusted model, the unstable MHO group showed the highest risk of T2DM (hazard ratio [HR], 4.67; 95% confidence interval [CI], 4.58 to 4.77). The unstable MHNW group had a higher risk of T2DM than stable MHO group ([HR, 3.23; 95% CI, 3.16 to 3.30] vs. [HR, 1.81; 95% CI, 1.76 to 1.85]). The stable MHO group showed a higher risk of T2DM than the stable MHNW group. The influence of the transition into a metabolically unhealthy phenotype on T2DM incidence was greater in subjects with aged <65 years, women, and those with weight gain.
Conclusion: Metabolically healthy phenotype was transient both in normal weight and obese individuals. Maintaining metabolic health was critical for the prevention of T2DM, irrespective of their baseline body mass index.

Background: To evaluate the imaging features, clinical manifestations, and prognosis of patients with thyroid nodule rupture after radiofrequency ablation (RFA).
Methods: The records of 12 patients who experienced thyroid nodule rupture after RFA at four Korean thyroid centers between March 2010 and July 2017 were retrospectively reviewed. Clinical data evaluated included baseline patient characteristics, treatment methods, initial presenting symptoms, imaging features, treatment, and prognosis.
Results: The most common symptoms of post-RFA nodule rupture were sudden neck bulging and pain. Based on imaging features, the localization of nodule rupture was classified into three types: anterior, posterolateral, and medial types. The anterior type is the most often, followed by posterolateral and medial type. Eight patients recovered completely after conservative treatment. Four patients who did not improve with conservative management required invasive procedures, including incision and drainage or aspiration.
Conclusion: Thyroid nodule rupture after RFA can be classified into three types based on its localization: anterior, posterolateral, and medial types. Because majority of thyroid nodule ruptures after RFA can be managed conservatively, familiarity with these imaging features is essential in avoiding unnecessary imaging workup or invasive procedures.