Vitamin D deficiency affects >60% of the Korean population. Recent reports in Caucasian, African American, and Chinese populations indicate an association between vitamin D status and related single nucleotide polymorphisms (SNPs), but specific associations differ among study populations. We investigated the relationship between five SNPs involved in the vitamin D metabolic pathway (DHCR7 rs12785878, GC rs2282679, CYP2R1 rs12794714, CYP2R1 rs10741657, and CYP24A1 rs6013897) and serum 25-hydroxyvitamin D [25(OH)D] status in Koreans using the Korea National Health and Nutrition Examination Survey, a nationwide database. Whether the association was modified by demographic and lifestyle factors, including sex, body mass index (BMI), smoking status, drinking status, physical activity, and sun exposure, were also investigated. The results showed the serum level of 25(OH)D was associated with rs12785878, rs2282679, and rs12794714 genotypes, but not with rs10741657 or rs6013897. The genetic risk score (GRS) calculated by summing the number of alleles of these 5 SNPs was associated with low circulating levels of 25(OH)D. However, the negative association between 25(OH)D and GRS was modified by obesity and sun exposure. Specifically, negative associations between 25(OH)D and GRS were present in adults with lower BMI (<25 kg/m²) and longer sun exposure time (≥2 h/day). In conclusion, common variants of vitamin D-related SNPs are associated with vitamin D status in Koreans, and this genetic effect was masked when BMI ≥25 kg/m² or sun exposure <2 h/day. Additionally, seasonal variation must be considered in future studies among Koreans.

Hashimoto’s thyroiditis (HT) is considered a T helper-type 1 (Th1) cytokine-dominant autoimmune thyroid disease. Caveolin-1 (Cav-1), a part of the thyroxisome multiprotein complex, is localized at the apical pole of thyrocytes and is indispensable for synthesis of thyroid hormones and modulation of oxidative stress in order to avoid cell damage and apoptosis. Reduced autophagy induces thyroid follicular cells (TFC) apoptosis by activating reactive oxygen species (ROS) in HT patients. Nevertheless, whether Cav-1 has roles in the regulation of autophagy remains largely unclear. In this study, we examined Th1 cytokines and Cav-1 expression in HT thyroid tissues, determined the effects of interleukin-1beta (IL-1β) and interferon-gamma (IFN-γ) on Cav-1 and autophagy activity in TFC, and investigated the association between Cav-1 and autophagy activity in vitro. Our results indicate that higher levels of IL-1β and IFN-γ and lower levels of Cav-1 were expressed in thyroid tissues of HT patients than in those of normal controls. Cav-1 mRNA and protein levels were significantly decreased in TFC exposed to IL-1β and IFN-γ, accompanied by decreased expression of autophagy-related protein LC3B-II. Interestingly, small interfering RNA (siRNA)-mediated Cav-1 knockdown in TFC reduced LC3B-II protein expression. Taken together, these results suggest that lack of Cav-1 expression inhibited autophagy activity in TFC exposed to Th1 cytokines (IL-1β and IFN-γ), which might be a novel pathogenetic mechanism of HT.

This paper aims to investigate the influence of lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibitor, darapladib, on insulin resistance (IR) in streptozotocin (STZ)-induced diabetic pregnant rats. The rat models were divided into Control (normal pregnancy), STZ + saline (STZ-induced diabetic pregnant rats), STZ + Low-dose and STZ + High-dose darapladib (STZ-induced diabetic pregnant rats treated with low-/high-dose darapladib) groups. Pathological changes were observed by Hematoxylin-eosin (HE) and Immunohistochemistry staining. Lp-PLA2 levels were determined by enzyme-linked immunosorbent assay (ELISA). An automatic biochemical analyzer was used to measure the serum levels of biochemical indicators, and homeostatic model assessment for insulin resistance (HOMA-IR) and insulin sensitivity index (ISI) were calculated. Western blot was applied to determine levels of inflammatory cytokines. Compared with Control group, rats in the STZ + saline group were significantly decreased in body weight, the number of embryo implantation, the number of insulin positive cells and pancreatic islet size as well as the islet endocrine cells, and high-density lipoprotein (HDL-C) level, but substantially increased in Lp-PLA2, low-density lipoprotein (LDL-C), fatty acids (FFA), serum total cholesterol (TC), triglyceride (TG) levels. Moreover, the increased fasting plasma glucose (FPG) and HOMA-IR and inflammatory cytokines but decreased fasting insulin (FINS) and ISI were also found in diabetic pregnant rats. On the contrary, rats in the darapladib-treated groups were just opposite to the STZ + saline group, and STZ + High-dose group improved better than STZ + Low-dose group. Thus, darapladib can improve lipid metabolism, and enhance insulin sensitivity of diabetic pregnant rats by regulating inflammatory cytokines.

Several articles have shown the inverse association between total testosterone (TT) or sex hormone–binding globulin (SHBG) and hepatic steatosis. No articles report associations of TT, SHBG, free testosterone (FT), and bioavailable testosterone (BioT) with aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratios. Therefore, we investigated the associations of TT, FT, BioT and SHBG with hepatic steatosis and AST/ALT ratios. A total of 218 men were enrolled. We diagnosed hepatic steatosis by ultrasound. TT and SHBG showed a reduced risk for hepatic steatosis when analyzed with or without adjusting for age, smoking, alcohol consumption and physical activity. Compared with the lowest quartile, the ORs for hepatic steatosis in the third and fourth quartiles (0.32 [95% CI: 0.14–0.75] and 0.27 [95% CI: 0.10–0.73], respectively) of SHBG were significantly lower after adjustments. The OR for hepatic steatosis in the fourth quartile of TT (0.41 [95% CI: 0.17–0.95]) was significantly lower than in the lowest quartile after adjustments. The mean AST/ALT ratios in men with hepatic steatosis were lower than those without hepatic steatosis (0.83 and 1.04, respectively), due to the elevated ALT levels in hepatic steatosis groups. Furthermore, TT and SHBG were positively associated with AST/ALT ratios with and without adjustments. In conclusion, higher TT and SHBG levels in men are associated with the reduced risk of hepatic steatosis and elevated AST/ALT ratios, independent of age, smoking, alcohol consumption and physical activity.

Previous studies have shown a relationship between type 2 diabetes mellitus and birth weight. We performed this meta-analysis to resolve the problem of inconsistent results. We conducted a literature search of PubMed, Embase and the Cochrane Library using “Diabetes Mellitus, Type 2,” “Birth Weight,” and some related free words. Twenty-one studies were included in accordance with inclusion and exclusion criteria, involving a total of 313,165 participants and 22,341 type 2 diabetes mellitus cases. A modified version of the Newcastle-Ottawa Scale was used to evaluate the methodological quality of studies included. We used Review Manager 5.3 for data merging and statistical analysis. Results were expressed as odds ratio (OR) and 95% confidence interval (95% CI). The risk of diabetes with low birth weight (<2,500 g) was higher than that with birth weight ≥2,500 g, (OR = 1.51, 95% CI: 1.43, 1.58). Compared with normal birth weight (2,500–4,000 g), low birth weight, but not high birth weight, increased the risk of diabetes (OR = 1.41, 95% CI: 1.26, 1.58). There is a negative association between birth weight and the future risk of type 2 diabetes mellitus.

Diagnosis of adrenal insufficiency requires evaluation by dynamic stimulation tests. The insulin tolerance test (ITT) is accepted as the gold-standard test for the evaluation of hypothalamo-pituitary-adrenal (HPA) axis but the test is unpleasant and dangerous. Although it takes more time, glucagon stimulation test (GST) is a good alternative to ITT. The primary aim of this study was to compare the ITT and GSTs in the evaluation of HPA axe in patients with pituitary disorders. We conducted a prospective study in which ITT and GST were performed within 7 days in 81 patients. Serum cortisol was measured. We divided our population in Group 1 (G1): Adrenal Insufficiency (Peak cortisol under ITT <200 ng/mL) and Group 2 (G2): normal response (Peak cortisol under ITT >200 ng/mL). Receiver-operating characteristic (ROC) analysis was performed to identify the thresholds for GST. The mean peak of cortisol under GST was not significantly different from that obtained after ITT in the whole cohort (182.67 ± 89.07 ng/mL vs. 179.75 ± 79.01 ng/mL), and it was significantly reduced in patients of G1 (p < 10^–3). ROC curve analysis showed that the best diagnostic accuracy was obtained with a peak cortisol cut-off to GST of 167 ng/mL (sensitivity, 89%; specificity, 79%). Using this cut-off, 86.4% of the patients were correctly classified. In our prospective series, GST is a potential accurate and safe alternative test for the assessment HPA. Test-specific cut-offs should be applied to avoid misinterpretation.

Type 1 diabetes mellitus (T1DM) is a syndrome of loss of glucose homeostasis caused by the loss of β cell chronic autoimmunity against islet cells. Islet-specific epitopes coupled antigen presenting cells by Ethylenecarbodiimide (ECDI) is a promising strategy to induce antigen-specific tolerance. However, single epitope induced tolerance is insufficient to prevent the onset of T1DM. The aim of this study is to evaluate the efficacy of whole islet antigens in preventing the onset and progression of T1DM and identify the underlying immune mechanism in NOD mice. In this study, the whole islet antigens, derived from islet lysate isolated from BALB/c mice, were coupled to splenocytes of BALB/c mice by ECDI fixation (SP-Islet lysate), and then intravenously administrated to NOD mice. The results showed that, compared with control group, SP-Islet lysate group significantly decreased T1DM incidence and improved the survival of NOD mice. SP-Islet lysate treated mice had reduced insulitis score and autoantibody levels, and improved glucose tolerance and insulin/glucagon production. Furthermore, the effector memory T cells (T_EMs) were downregulated and regulatory T cells (Tregs) were upregulated by the SP-Islet lysate treatment, with reduced populations of Th1&Th17 cells. In conclusion, ECDI-fixed splenocytes carrying whole islet antigens effectively prevented the onset of T1DM in NOD mice, via suppressing the production of autoantibodies and inducing anergy of autoreactive T cells.

Weight reduction is important in patients with sleep-disordered breathing (SDB). In Japanese patients, slight weight reduction is effective for improving the severity of SDB. However, the effect of weight reduction after administration of sodium glucose co-transporter 2 (SGLT2) inhibitor for SDB remains unclear. The aim of this study was to evaluate the improvement of SDB from baseline after administration of dapagliflozin (5 mg) once daily for 24 weeks among Japanese patients with obesity and type 2 diabetes mellitus. Thirty Japanese patients with type 2 diabetes mellitus and SDB were enrolled in a 24-week, prospective, open-label, single-arm, multicentre trial. SDB was defined as at least five 3% oxygen desaturation index (ODI) events per hour, and moderate to severe SDB was defined as at least 15 ODI events per hour. The primary endpoint was the change in 3% ODI between before dapagliflozin administration and at 24 weeks. The prevalence of moderate to severe SDB was 20% in the present study. After administration of dapagliflozin, fasting glucose, HbA1c, aspartate aminotransferase, total cholesterol, low-density lipoprotein cholesterol, and estimated globular filtration rate decreased significantly. The improvement of 3% ODI was observed in patients with moderate to severe SDB but not mild SDB (from 25.0 ± 3.8 at baseline to 18.5 ± 6.1 at 24 weeks, p = 0.017). In conclusion, dapagliflozin might improve moderate to severe SDB but not mild SDB in Japanese patients with obesity and type 2 diabetes mellitus.

Intravenous (i.v.) glucocorticosteroids (GCs) constitute the first-line treatment for active and moderate-to-severe Graves’ orbitopathy (GO). In cases of persistent disease, rituximab, a monoclonal anti-CD20 antibody, may be used, although studies have yielded conflicting results. In case 1, a 50-year-old female heavy smoker presented with severe bilateral disfiguring eyelid edema of four months, bilateral exophthalmos and a clinical activity score (CAS) of 5/7. Laboratory investigation showed thyrotoxicosis and high thyroid-stimulating immunoglobulin (TSI) levels [32 IU/L (normal <1.75]. After minor improvement by i.v. methylprednisolone and standard retrobulbar radiotherapy (20 Gy), her visual acuity progressively declined to “hand motion”. Rituximab was administered (two pulses of 500 mg, two weeks apart), with significant response. At 3 1/2 years of follow-up, CAS is 0/7 and CD20+ lymphocytes remain at the lower normal range. In case 2, a 78-year-old non-smoker male was referred for management of severe active GO, one month after total thyroidectomy for Graves’ thyrotoxicosis (TSI: 6.74 IU/L). Over the preceding two-three months, severe GO manifested with chemosis, constant diplopia, loss of color vision and acuity of 1/10 bilaterally (CAS: 7/7). Following partial response to i.v. methylprednisolone and concomitant radiotherapy, rituximab (two pulses of 500 mg each, two weeks apart), was administered. Vision partially recovered and GO remains in remission one year later, even after ¹³¹I (100 mCi) administration for papillary thyroid carcinoma (TSI: 0.9 IU/L and CD20+ count at the lower normal range). In conclusion, rituximab may be an effective second-line therapy in GO patients, providing long-lasting remission.