My Wife Is My Insurance Policy: Household Bargaining and Couples' Purchase of Long-Term Care Insurance.

This paper examines household decisions over long-term care insurance (LTCI) purchases through a bargaining lens. Long-term care insurance purchase is a discrete decision around which spouses' interests may diverge substantially. The cost of buying LTCI is typically borne by both spouses, but the benefits of LTCI go disproportionately to women, who are more likely to need long-term care for themselves, and to benefit from the asset protection and other support LTCI offers in the event their husband needs care. Using panel data on married couples ages 50-75 from the US Health and Retirement Study (HRS), we test and find support for the hypothesis that spouses' relative bargaining power is related to LTCI purchase decisions. In particular, when husbands have final say in household decisions, LTCI coverage is less likely. The findings suggest that spouse's relative bargaining power matters for health care choices and, therefore, for the welfare of older men and women.

Generation of iPSC-derived insulin-producing cells from patients with type 1 and type 2 diabetes compared with healthy control.

For alternative sources of ß cells, patient-specific induced pluripotent stem cells (iPSCs) could be promising, as cells derived from the "self" allow autologous transplantation. However, only a few studies have investigated insulin-producing cells (IPCs) using iPSCs of patients with type 1 diabetes (T1D). In this study, we generated IPCs using iPSCs derived from patients with T1D and type 2 diabetes (T2D) and compared them with IPCs from a non-diabetic (ND) individual. To facilitate differentiation of human iPSCs into IPCs, we induced PDX-1 gene expression using Ad-PDX-1/VP16. IPCs derived from T1D- and T2D-specific iPSCs expressed islet-specific markers such as Pdx-1, MafA, Beta2/NeuroD, and insulin, similar to IPCs derived from ND-specific iPSCs. In addition, IPCs derived from T1D- and T2D-specific iPSCs showed comparable glucose-stimulated insulin secretion as IPCs derived from ND-specific iPSCs. These results suggest the potential for autologous transplantation using patient-specific iPSCs in patients with T1D and T2D. This study was clinically significant because the majority of people with diabetes have T2D and insulin secretion declines over time in T2D. To the best of our knowledge, this is the first study to generate and simultaneously compare IPCs from ND-, T1D-, and T2D-specific iPSCs.

Efficacies of Stem Cell Therapies for Functional Improvement of the ß Cell in Patients with Diabetes: A Systematic Review of Controlled Clinical Trials.

BACKGROUND AND OBJECTIVES: This study was performed to investigate whether stem cell therapy enhances ß cell function by meta-analysis with proper consideration of variability of outcome measurements in controlled trial of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) patients. METHODS: A systematic search was performed from inception to January 2018 in PubMed, EMBASE, and Cochrane databases. ß cell function was assessed by stimulated C-peptide, fasting C-peptide, normal glycosylated hemoglobin levels (HbA1C), and exogenous insulin dose patterns. The quality of the studies were assessed by both the Cochrane Collaboration's Risk of Bias (ROB) for Randomized controlled trials and the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) for non-randomized controlled trials. RESULTS: From the selected final 15 articles, total of 16 trials were analyzed. There were 6 T1DM trials (total 153 cases) and 10 T2DM trials (total 457 cases). In T2DM patients, the changes in stimulated C-peptide, HbA1c, and exogenous insulin dose versus baseline showed a favorable pattern with a significant heterogeneity in stem cell therapy. In T1DM, there was no significant difference between control group and stem cell therapy group in three indicators except for HbA1c. Most of the studies were rated as having high risk of bias in the quality assessment. CONCLUSIONS: The stem cell therapy for DM patients is not effective in T1DM but seems to be effective in improving the ß cell function in T2DM. However the observed effect should be interpreted with caution due to the significant heterogeneity and high risk of bias within the studies. Further verification through a rigorously designed study is warranted.

Metabolic health is more closely associated with decrease in lung function than obesity.

OBJECTIVE: Previous studies have evaluated the link between metabolic syndrome and obesity with impaired lung function, however findings have been controversial. We aimed to compare lung function among subjects with different metabolic health and obesity status. METHODS: Total 10,071 participants were evaluated at the Health Promotion Center in Seoul St. Mary's Hospital between January 2012 and December 2014. Being metabolically healthy was defined as having fewer than three of the following risk factors: high blood pressure, high fasting blood glucose, high triglyceride, low high-density lipoprotein cholesterol and abdominal obesity. Obesity status was defined as body mass index (BMI) higher than 25 kg/m2. Analyses of pulmonary function were performed in four groups divided according to metabolic health and obesity: metabolically healthy non-obese (MHNO), metabolically health obese (MHO), metabolically unhealthy non-obese (MUHNO), and metabolically unhealthy obese (MUHO). RESULTS: Metabolically unhealthy subjects were more prone to decreased lung function compared with their metabolically healthy counterparts, regardless of obesity status. When multinomial logistic regression analysis was performed according to quartiles of forced vital capacity (FVC) or forced expiratory volume in 1 second (FEV1) (% pred), after adjusting for age, sex, and smoking status, odds ratio (OR) for the lowest FVC and FEV1 (% pred) quartiles were significantly higher in MUHO subjects (1.788 [95% CI, 1.531-2.089] and 1.603 [95% CI, 1.367-1.881]) and lower in MHO subjects (0.768 [95% CI, 0.654-0.902] and 0.826 [95% CI, 0.700-0.976]) with MHNO group as the reference, when OR for highest FVC and FEV1 quartiles were considered as 1.0. CONCLUSION: Metabolic health is more closely associated with impaired lung function than obesity.

Acarbose Add-on Therapy in Patients with Type 2 Diabetes Mellitus with Metformin and Sitagliptin Failure: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study.

BACKGROUND: We evaluated the efficacy and safety of acarbose add-on therapy in Korean patients with type 2 diabetes mellitus (T2DM) who are inadequately controlled with metformin and sitagliptin. METHODS: A total of 165 subjects were randomized to metformin and sitagliptin (Met+Sita, n=65), metformin, sitagliptin, and acarbose (Met+Sita+Acarb, n=66) and sitagliptin and acarbose (Sita+Acarb, exploratory assessment, n=34) therapy in five institutions in Korea. After 16 weeks of acarbose add-on or metformin-switch therapy, a triple combination therapy was maintained from week 16 to 24. RESULTS: The add-on of acarbose (Met+Sita+Acarb group) demonstrated a 0.44%±0.08% (P<0.001 vs. baseline) decrease in glycosylated hemoglobin (HbA1c) at week 16, while changes in HbA1c were insignificant in the Met+Sita group (-0.09%±0.10%, P=0.113). After 8 weeks of triple combination therapy, HbA1c levels were comparable between Met+Sita and Met+Sita+Acarb group (7.66%±0.13% vs. 7.47%±0.12%, P=0.321). Acarbose add-on therapy demonstrated suppressed glucagon secretion (area under the curve of glucagon, 4,726.17±415.80 ng·min/L vs. 3,314.38±191.63 ng·min/L, P=0.004) in the absence of excess insulin secretion during the meal tolerance tests at week 16 versus baseline. The incidence of adverse or serious adverse events was similar between two groups. CONCLUSION: In conclusion, a 16-week acarbose add-on therapy to metformin and sitagliptin, effectively lowered HbA1c without significant adverse events. Acarbose might be a good choice as a third-line therapy in addition to metformin and sitagliptin in Korean subjects with T2DM who have predominant postprandial hyperglycemia and a high carbohydrate intake.

Study Time after School and Habitual Eating Are Associated with Risk for Obesity among Overweight Korean Children: A Prospective Study.

OBJECTIVE: To investigate behavioral factors that contribute to the development of obesity among overweight children. METHODS: Among a community sample of 884 children aged 9-13 years, 833 children completed a baseline and 1-year follow-up examination that included anthropometrics, physical fitness, and behavioral factors. RESULTS: During the follow-up period, BMI for most children with normal weight or obesity did not change. However, among overweight children (n = 100), about one-third developed obesity (n = 26), while the others were categorized as normal weight (n = 32) or overweight (n = 42) after 1 year. Characteristics of overweight children at baseline and follow-up were analyzed. Those who developed obesity showed a notable increase in blood pressure as well as in BMI, waist circumference, and body fat over 1 year. At baseline, this group spent more time studying after school compared to overweight children who did not develop obesity, while there were no differences in time spent viewing television or engaging in vigorous physical activity. Eating outside the home, fast food consumption, and habitual eating in the absence of hunger were more common at baseline in those who did versus those who did not develop obesity. After adjusting for age, sex, and BMI, spending more time studying after school and habitual eating without hunger were associated with the development of obesity. CONCLUSION: Among Korean overweight children, study time after school and habitual eating without hunger were associated with an increased risk for development of obesity.

Reliability and Validity of the Korean Version of the General-Food Craving Questionnaire-Trait for Children.

OBJECTIVE: The General-Food Craving Questionnaire-Trait (G-FCQ-T) is a validated, assessment scale for food craving. The aim of this study was to measure its reliability and validity for Korean children. METHODS: A total of 172 children (94 boys and 78 girls) were selected to fill out a set of questionnaires, including the G-FCQ-T, the Children's version of the Dutch Eating Behavior Questionnaire (DEBQ-C), and the Three-Factor Eating Questionnaire (TFEQ) in the Korean language. RESULTS: The internal consistency (Cronbach's alpha=0.933) and test-retest reliability (r=0.653) were satisfactory. The G-FCQ-T showed a significantly positive correlation with the DEBQ-C (r=0.560) and the TFEQ (r=0.397). The optimum cutoff score of the G-FCQ-T set by Receiver Operating Characteristics analysis was 51, with sensitivity and specificity of 0.833 and 0.825, respectively, for children. CONCLUSION: The G-FCQ-T showed good reliability and validity for assessing food craving for children and could become a practial instrument in clinical and research settings.

Factors associated with greater benefit of a national reimbursement policy for blood glucose test strips in adult patients with type 1 diabetes: A prospective cohort study.

AIMS/INTRODUCTION: We aimed to identify factors independently associated with greater benefit of a national reimbursement policy for blood glucose test strips in adult patients with type 1 diabetes, in terms of glycemic control and the rate of severe hypoglycemia. MATERIALS AND METHODS: This was a prospective cohort study of 466 adult patients with type 1 diabetes from five tertiary referral hospitals who registered for a national reimbursement program for blood glucose strips and were then followed-up for 12 months. Factors associated with a > 5% reduction in glycated hemoglobin (HbA1c) and decreased rate of severe hypoglycemia (SH) at 12 months from baseline were evaluated. RESULTS: At the end of the 12 months of follow up, 158 of 466 patients (33.9%) achieved >5% reduction in HbA1c, and 47 of 111 patients (42.3%) had a decreased rate of SH relative to baseline. Higher HbA1c (P < 0.001), lower total daily insulin dose at baseline (P = 0.048) and an increase in self-monitoring of blood glucose (SMBG) frequency during follow up (P = 0.001) were independently associated with >5% reduction in HbA1c. A higher SMBG frequency (P < 0.001), higher rate of SH at baseline (P = 0.029) and lack of hypoglycemic unawareness (P = 0.044) were independently associated with an increase in the frequency of SMBG during follow up. Higher SMBG frequency at baseline (P < 0.001) was independently associated with a decreased rate of SH. CONCLUSIONS: Several factors, including higher SMBG frequency at baseline, were independently associated with reduced HbA1c and a decreased rate of severe hypoglycemia, showing that patients with these characteristics derive the most benefit from reimbursement of blood glucose test strips.

Physician-Directed Diabetes Education without a Medication Change and Associated Patient Outcomes.

BACKGROUND: When patients with diabetes mellitus (DM) are first referred to a hospital from primary health care clinics, physicians have to decide whether to administer an oral hypoglycemic agent (OHA) immediately or postpone a medication change in favor of diabetes education regarding diet or exercise. The aim of this study was to determine the effect of diabetes education alone (without alterations in diabetes medication) on blood glucose levels. METHODS: The study was conducted between January 2009 and December 2013 and included patients with DM. The glycosylated hemoglobin (HbA1c) levels were evaluated at the first visit and after 3 months. During the first medical examination, a designated doctor also conducted a diabetes education session that mainly covered dietary management. RESULTS: Patients were divided into those who received no diabetic medications (n=66) and those who received an OHA (n=124). Education resulted in a marked decrease in HbA1c levels in the OHA group among patients who had DM for <1 year (from 7.0%±1.3% to 6.6%±0.9%, P=0.0092) and for 1 to 5 years (from 7.5%±1.8% to 6.9%±1.1%, P=0.0091). Those with DM >10 years showed a slightly lower HbA1c target achievement rate of <6.5% (odds ratio, 0.089; P=0.0024). CONCLUSION: For patients who had DM for more than 5 years, higher doses or changes in medication were more effective than intensive active education. Therefore, individualized and customized education are needed for these patients. For patients with a shorter duration of DM, it may be more effective to provide initial intensive education for diabetes before prescribing medicines, such as OHAs.

DNA Methylation Profiles of Blood Cells Are Distinct between Early-Onset Obese and Control Individuals.

Obesity is a highly prevalent, chronic disorder that has been increasing in incidence in young patients. Both epigenetic and genetic aberrations may play a role in the pathogenesis of obesity. Therefore, in-depth epigenomic and genomic analyses will advance our understanding of the detailed molecular mechanisms underlying obesity and aid in the selection of potential biomarkers for obesity in youth. Here, we performed microarray-based DNA methylation and gene expression profiling of peripheral white blood cells obtained from six young, obese individuals and six healthy controls. We observed that the hierarchical clustering of DNA methylation, but not gene expression, clearly segregates the obese individuals from the controls, suggesting that the metabolic disturbance that occurs as a result of obesity at a young age may affect the DNA methylation of peripheral blood cells without accompanying transcriptional changes. To examine the genome-wide differences in the DNA methylation profiles of young obese and control individuals, we identified differentially methylated CpG sites and investigated their genomic and epigenomic contexts. The aberrant DNA methylation patterns in obese individuals can be summarized as relative gains and losses of DNA methylation in gene promoters and gene bodies, respectively. We also observed that the CpG islands of obese individuals are more susceptible to DNA methylation compared to controls. Our pilot study suggests that the genome-wide aberrant DNA methylation patterns of obese individuals may advance not only our understanding of the epigenomic pathogenesis but also early screening of obesity in youth.

Antifibrotic effect of rapamycin containing polyethylene glycol-coated alginate microcapsule in islet xenotransplantation.

Islet microencapsulation is an attractive strategy for the minimization or avoidance of life-long immunosuppression after transplantation. However, the clinical implementation of this technique is currently limited by incomplete biocompatibility. Thus, the aim of the present study was to demonstrate the improved biocompatibility of rapamycin-containing polyethylene glycol (Rapa-PEG)-coating on alginate microcapsules containing xenogeneic islets. The Rapa-PEG-coating on the alginate layer was observed using scanning electron microscopy (SEM) and the molecular cut-off weight of the microcapsules was approximately 70 kDa. The viabilities of the alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets were lower than the viability of the naked islets just after encapsulation, but these the differences diminished over time in culture dishes. Rapa-PEG-coating on the alginate capsules effectively decreased the proliferation of macrophage cells compared to the non-coating and alginate coating of xenogeneic pancreas tissues. Glucose-stimulated insulin secretion did not significantly differ among the groups prior to transplantation. The random blood glucose levels of diabetic mice significantly improved following the transplantation of alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets, but there were no significant differences between these two groups. However, there was a significant decrease in the number of microcapsules with fibrotic cell infiltration in the Rapa-PEG-coated alginate microcapsule group compared to the alginate microcapsule group. In conclusion, Rapa-PEG-coating might be an effective technique with which to improve the biocompatibility of microcapsules containing xenogeneic islets. Copyright © 2015 John Wiley & Sons, Ltd.

An Internet-based health gateway device for interactive communication and automatic data uploading: Clinical efficacy for type 2 diabetes in a multi-centre trial.

Introduction The aim of this study was to improve the quality of diabetes control and evaluate the efficacy of an Internet-based integrated healthcare system for diabetes management and safety. Methods We conducted a large-scale, multi-centre, randomized clinical trial involving 484 patients. Patients in the intervention group ( n = 244) were treated with the Internet-based system for six months, while the control group ( n = 240) received the usual outpatient management over the same period. HbA1c, blood chemistries, anthropometric parameters, and adverse events were assessed at the beginning of the study, after three months, and the end of the study. Results There were no initial significant differences between the groups with respect to demographics and clinical parameters. Upon six-month follow-up, HbA1c levels were significantly decreased from 7.86 ± 0.69% to 7.55 ± 0.86% within the intervention group ( p < 0.001) compared to 7.81 ± 0.66% to 7.70 ± 0.88% within the control group. Postprandial glucose reduction was predominant. A subgroup with baseline HbA1c higher than 8% and good compliance achieved a reduction of HbA1c by 0.8 ± 1.05%. Glucose control and waist circumference reduction were more effective in females and subjects older than 40 years of age. There were no adverse events associated with the intervention. Discussion This e-healthcare system was effective for glucose control and body composition improvement without associated adverse events in a multi-centre trial. This system may be effective in improving diabetes control in the general population.

Differential association of body mass index on glycemic control in type 1 diabetes.

BACKGROUND: In contrast to type 2 diabetes, the association of body mass index (BMI) with glycemic control in type 1 diabetes (T1D) remains unclear. We investigated the relationship between BMI and average HbA1c levels in subjects with T1D. METHOD: In this multi-centre observational study, we analysed 719 subjects with T1D aged ≥18 years. Average HbA1c levels over 18 months and other clinical and laboratory parameters were evaluated. RESULTS: The mean age and duration of diabetes at baseline were 41.5 ± 13.9 and 11.3 ± 8.7 years, respectively. A U-shaped correlation between BMI and 18-month average HbA1c levels was documented by a spline curve. Based on this finding, subjects were divided into three groups according to BMI (group I, <21; group II, 21-23; and group III, ≥23 kg/m2 ). In group I, the BMI negatively correlated with average HbA1c (r = -0.172, p = 0.011), while a positive relationship was observed (r = 0.162, p = 0.012) in group III. Average HbA1c levels were lower and the proportion of individuals with well-controlled glycemia (HbA1c <7%) were increased in the higher BMI tertile group among subjects with group I as well as in the lower BMI tertile group among subjects with group III BMI. After adjustment with additional covariates in the multiple regression model, these associations between BMI and HbA1c levels according to the different BMI ranges remained significant. CONCLUSIONS: In Korean subjects with T1D, an inverse relationship of BMI with HbA1c levels was observed in the low BMI group, while a positive correlation was shown in the high BMI group. Copyright © 2016 John Wiley & Sons, Ltd.

Suppression of ROS Production by Exendin-4 in PSC Attenuates the High Glucose-Induced Islet Fibrosis.

Pancreatic stellate cells (PSCs) play a major role to fibrotic islet destruction observed in diabetic patients and animal model of diabetes. Exendin-4 (Ex-4) is a potent insulinotropic agent and has been approved for the treatment of type 2 diabetes. However, there have been no reports demonstrating the effects of Ex-4 on pancreatic islet fibrosis. In this study, Ex-4 treatment clearly attenuated fibrotic islet destruction and improved glucose tolerance and islet survival. GLP-1 receptor expression was upregulated during activation and proliferation of PSCs by hyperglycemia. The activation of PKA pathway by Ex-4 plays a role in ROS production and angiotensin II (Ang II) production. Exposure to high glucose stimulated ERK activation and Ang II-TGF- ß1 production in PSCs. Interestingly, Ex-4 significantly reduced Ang II and TGF-ß1 production by inhibition of ROS production but not ERK phosphorylation. Ex-4 may be useful not only as an anti-diabetic agent but also as an anti-fibrotic agent in type 2 diabetes due to its ability to inhibit PSC activation and proliferation and improve islet fibrosis in OLETF rats.

Reduction of Sulfonylurea with the Initiation of Basal Insulin in Patients with Inadequately Controlled Type 2 Diabetes Mellitus Undergoing Long-Term Sulfonylurea-Based Treatment.

BACKGROUND: There were a limited number of studies about ß-cell function after insulin initiation in patients exposed to long durations of sulfonylurea treatment. In this study, we aimed to evaluate the recovery of ß-cell function and the efficacy of concurrent sulfonylurea use after the start of long-acting insulin. METHODS: In this randomized controlled study, patients with type 2 diabetes mellitus (T2DM), receiving sulfonylurea for at least 2 years with glycosylated hemoglobin (HbA1c) >7%, were randomly assigned to two groups: sulfonylurea maintenance (SM) and sulfonylurea reduction (SR). Following a 75-g oral glucose tolerance test (OGTT), we administered long-acting basal insulin to the two groups. After a 6-month follow-up, we repeated the OGTT. RESULTS: Among 69 enrolled patients, 57 completed the study and were analyzed: 31 in the SM and 26 in the SR group. At baseline, there was no significant difference except for the longer duration of diabetes and lower triglycerides in the SR group. After 6 months, the HbA1c was similarly reduced in both groups, but there was little difference in the insulin dose. In addition, insulin secretion during OGTT was significantly increased by 20% to 30% in both groups. A significant weight gain was observed in the SM group only. The insulinogenic index was more significantly improved in the SR group. CONCLUSION: Long-acting basal insulin replacement could improve the glycemic status and restore ß-cell function in the T2DM patients undergoing sulfonylurea-based treatment, irrespective of the sulfonylurea dose reduction. The dose reduction of the concurrent sulfonylurea might be beneficial with regard to weight grain.

Triglyceride glucose index, a marker of insulin resistance, is associated with coronary artery stenosis in asymptomatic subjects with type 2 diabetes.

BACKGROUND: Insulin resistance is one of the most important contributing factors to cardiovascular disease. This study aimed to investigate the association between coronary artery stenosis (CAS) and triglyceride glucose index (TyG index), a simple insulin resistance marker, in asymptomatic subjects with type 2 diabetes. METHODS: We recruited asymptomatic adults with type 2 diabetes but without previous history of coronary heart disease (n = 888). Significant CAS was defined as maximum intraluminal stenosis ≥70 % by coronary CT angiography. TyG index was calculated as log [fasting triglycerides (mg/dl) x fasting glucose (mg/dl)/2]. RESULTS: Mean age was 63.8 ± 9.5 and 58.9 % of the subjects were men. We analyzed the participants according to the tertile of TyG index. The TyG index was correlated with HOMA-IR (r = 0.397, P < 0.001), and subjects with higher tertile of TyG index were younger but showed worse clinical and metabolic parameters. The prevalence of CAS was higher in subjects with higher tertile of TyG compared with those with lower tertile of TyG (14 % vs. 7.8 %, P = 0.022). On multiple regression analysis, the highest tertile of TyG index was an independent risk factor for CAS after adjustment for other confounders (odds ratio, 3.19 [95 % CI, 1.371-7.424]). Subgroup analysis showed that TyG index showed more significant association with CAS in patients with risk factors such as old age, longer duration of diabetes, poor glycemic control, no statin use, and male gender. CONCLUSION: Higher TyG index is associated with increased risk of CAS in asymptomatic subjects with type 2 diabetes, particularly when they have risk factors for cardiovascular disease. TRIAL REGISTRATION: This study was retrospectively registered in ClinicalTrials. gov with the registration number of NCT02070926 in Feb 23, 2014.

Obesity, metabolic health, and mortality in adults: a nationwide population-based study in Korea.

BMI, metabolic health status, and their interactions should be considered for estimating mortality risk; however, the data are controversial and unknown in Asians. We aimed to investigate this issue in Korean population. Total 323175 adults were followed-up for 96 (60-120) (median [5-95%]) months in a nationwide population-based cohort study. Participants were classified as "obese" (O) or "non-obese" (NO) using a BMI cut-off of 25 kg/m(2). People who developed ≥1 metabolic disease component (hypertension, diabetes, dyslipidaemia) in the index year were considered "metabolically unhealthy" (MU), while those with none were considered "metabolically healthy" (MH). The MUNO group had a significantly higher risk of all-cause (hazard ratio, 1.28 [95% CI, 1.21-1.35]) and cardiovascular (1.88 [1.63-2.16]) mortality, whereas the MHO group had a lower mortality risk (all-cause: 0.81 [0.74-0.88]), cardiovascular: 0.73 [0.57-0.95]), compared to the MHNO group. A similar pattern was noted for cancer and other-cause mortality. Metabolically unhealthy status was associated with higher risk of all-cause and cardiovascular mortality regardless of BMI levels, and there was a dose-response relationship between the number of incident metabolic diseases and mortality risk. In conclusion, poor metabolic health status contributed more to mortality than high BMI did, in Korean adults.

Preadipocyte factor 1 induces pancreatic ductal cell differentiation into insulin-producing cells.

The preadipocyte factor 1 (Pref-1) is involved in the proliferation and differentiation of various precursor cells. However, the intracellular signaling pathways that control these processes and the role of Pref-1 in the pancreas remain poorly understood. Here, we showed that Pref-1 induces insulin synthesis and secretion via two independent pathways. The overexpression of Pref-1 activated MAPK signaling, which induced nucleocytoplasmic translocation of FOXO1 and PDX1 and led to the differentiation of human pancreatic ductal cells into ß-like cells and an increase in insulin synthesis. Concurrently, Pref-1 activated Akt signaling and facilitated insulin secretion. A proteomics analysis identified the Rab43 GTPase-activating protein as a downstream target of Akt. A serial activation of both proteins induced various granular protein syntheses which led to enhanced glucose-stimulated insulin secretion. In a pancreatectomised diabetic animal model, exogenous Pref-1 improved glucose homeostasis by accelerating pancreatic ductal and ß-cell regeneration after injury. These data establish a novel role for Pref-1, opening the possibility of applying this molecule to the treatment of diabetes.

Predictive Value of Glucose Parameters Obtained From Oral Glucose Tolerance Tests in Identifying Individuals at High Risk for the Development of Diabetes in Korean Population.

Previous studies suggest that the future risk for type 2 diabetes is not similar among subjects in the same glucose tolerance category. In this study, we aimed to evaluate simple intuitive indices to identify subjects at high risk for future diabetes development by using 0, 30, 120 minute glucose levels obtained during 75 g OGTTs from participants of a prospective community-based cohort in Korea.Among subjects enrolled at the Chungju Metabolic disease Cohort, those who performed an OGTT between 2007 and 2010 and repeated the test between 2011 and 2014 were recruited after excluding subjects with diabetes at baseline. Subjects were categorized according to their 30 minute glucose (G30) and the difference between 120 and 0 minute glucose (G(120-0)) levels with cutoffs of 9.75 and 2.50 mmol/L, respectively.Among 1126 subjects, 117 (10.39%) developed type 2 diabetes after 4 years. In diabetes nonconverters, increased insulin resistance was accompanied by compensatory insulin secretion, but this was not observed in converters during 4 years of follow-up. Subjects with G(120-0) ≥ 2.50 mmol/L or G30 ≥ 9.75 mmol/L demonstrated lower degrees of insulin secretion, higher degrees of insulin resistance, and ∼6-fold higher risk of developing future diabetes compared to their lower counterparts after adjustment for possible confounding factors. Moreover, subjects with high G(120-0) and high G30 demonstrated 22-fold higher risk for diabetes development compared to subjects with low G(120-0) and low G30.By using the G(120-0) and G30 values obtained during the OGTT, which are less complicated measurements than previously reported methods, we were able to select individuals at risk for future diabetes development. Further studies in different ethnicities are required to validate our results.

Long-term Efficacy and Biocompatibility of Encapsulated Islet Transplantation With Chitosan-Coated Alginate Capsules in Mice and Canine Models of Diabetes.

BACKGROUND: Clinical application of encapsulated islet transplantation is hindered by low biocompatibility of capsules leading to pericapsular fibrosis and decreased islet viability. To improve biocompatibility, we designed a novel chitosan-coated alginate capsules and compared them to uncoated alginate capsules. METHODS: Alginate capsules were formed by crosslinking with BaCl2, then they were suspended in chitosan solution for 10 minutes at pH 4.5. Xenogeneic islet transplantation, using encapsulated porcine islets in 1,3-galactosyltransferase knockout mice, and allogeneic islet transplantation, using encapsulated canine islets in beagles, were performed without immunosuppressants. RESULTS: The chitosan-alginate capsules showed similar pore size, islet viability, and insulin secretory function compared to alginate capsules, in vitro. Xenogeneic transplantation of chitosan-alginate capsules demonstrated a trend toward superior graft survival (P = 0.07) with significantly less pericapsular fibrosis (cell adhesion score: 3.77 ± 0.41 vs 8.08 ± 0.05; P < 0.001) compared to that of alginate capsules up to 1 year after transplantation. Allogeneic transplantation of chitosan-alginate capsules normalized the blood glucose level up to 1 year with little evidence of pericapsular fibrotic overgrowth on graft explantation. CONCLUSIONS: The efficacy and biocompatibility of chitosan-alginate capsules were demonstrated in xenogeneic and allogeneic islet transplantations using small and large animal models of diabetes. This capsule might be a potential candidate applicable in the treatment of type 1 diabetes mellitus patients, and further studies in nonhuman primates are required.