1.Amelioration of Insulin Resistance after Delivery Is Associated with Reduced Risk of Postpartum Diabetes in Women with Gestational Diabetes Mellitus
Heejun SON ; Joon Ho MOON ; Sung Hee CHOI ; Nam H. CHO ; Soo Heon KWAK ; Hak Chul JANG
Endocrinology and Metabolism 2024;39(5):701-710
Background:
Identifying risk factors for postpartum type 2 diabetes in women with gestational diabetes mellitus (GDM) is crucial for effective interventions. We examined whether changes in insulin sensitivity after delivery affects the risk of type 2 diabetes in women with GDM.
Methods:
This prospective cohort study included 347 women with GDM or gestational impaired glucose tolerance, who attended the follow-up visits at 2 months postpartum and annually thereafter. Changes in insulin sensitivity were calculated using the Matsuda index at GDM diagnosis and at 2 months postpartum (ΔMatsuda index). After excluding women with pregestational diabetes or those followed up only once, we analyzed the risk of postpartum type 2 diabetes based on the ΔMatsuda index tertiles.
Results:
The incidence of type 2 diabetes at the two-month postpartum visit decreased with increasing ΔMatsuda index tertiles (16.4%, 9.5%, and 1.8%, P=0.001). During a 4.1-year follow-up, 26 out of 230 women who attended more than two follow-up visits (11.3%) developed type 2 diabetes. Compared to the lowest tertile, subjects in the highest ΔMatsuda index tertile showed a significantly reduced risk of type 2 diabetes (hazard ratio, 0.33; 95% confidence interval, 0.12 to 0.93; P=0.036) after adjusting for confounders.
Conclusion
Improvement in insulin sensitivity after delivery is associated with a reduced risk of postpartum type 2 diabetes in women with GDM. Postpartum changes in insulin sensitivity could be a useful prediction for future type 2 diabetes development in women with GDM.
2.Genome-Wide Association Study on Longitudinal Change in Fasting Plasma Glucose in Korean Population
Heejin JIN ; Soo Heon KWAK ; Ji Won YOON ; Sanghun LEE ; Kyong Soo PARK ; Sungho WON ; Nam H. CHO
Diabetes & Metabolism Journal 2023;47(2):255-266
Background:
Genome-wide association studies (GWAS) on type 2 diabetes mellitus (T2DM) have identified more than 400 distinct genetic loci associated with diabetes and nearly 120 loci for fasting plasma glucose (FPG) and fasting insulin level to date. However, genetic risk factors for the longitudinal deterioration of FPG have not been thoroughly evaluated. We aimed to identify genetic variants associated with longitudinal change of FPG over time.
Methods:
We used two prospective cohorts in Korean population, which included a total of 10,528 individuals without T2DM. GWAS of repeated measure of FPG using linear mixed model was performed to investigate the interaction of genetic variants and time, and meta-analysis was conducted. Genome-wide complex trait analysis was used for heritability calculation. In addition, expression quantitative trait loci (eQTL) analysis was performed using the Genotype-Tissue Expression project.
Results:
A small portion (4%) of the genome-wide single nucleotide polymorphism (SNP) interaction with time explained the total phenotypic variance of longitudinal change in FPG. A total of four known genetic variants of FPG were associated with repeated measure of FPG levels. One SNP (rs11187850) showed a genome-wide significant association for genetic interaction with time. The variant is an eQTL for NOC3 like DNA replication regulator (NOC3L) gene in pancreas and adipose tissue. Furthermore, NOC3L is also differentially expressed in pancreatic β-cells between subjects with or without T2DM. However, this variant was not associated with increased risk of T2DM nor elevated FPG level.
Conclusion
We identified rs11187850, which is an eQTL of NOC3L, to be associated with longitudinal change of FPG in Korean population.
3.Do Magnets Have the Potential to Serve as a Stabilizer for the Shoulder Joint in Massive Rotator Cuff Tears?: A Biomechanical Cadaveric Study
Yoon Sang JEON ; Sang Hyun KO ; Yun Moon JEON ; Dong Jin RYU ; Jeong Seok KIM ; Hyun Soon PARK ; Min-Shik CHUNG ; Daniel KWAK ; Michelle H. MCGARRY ; Thay Q. LEE
Clinics in Orthopedic Surgery 2023;15(4):616-626
Background:
Disruption of the rotator cuff muscles compromises concavity compression force, which leads to superior migration of the humeral head and loss of stability. A novel idea of using the magnetic force to achieve shoulder stabilization in massive rotator cuff tears (MRCTs) was considered because the magnets can stabilize two separate entities with an attraction force. This study aimed to investigate the biomechanical effect of the magnetic force on shoulder stabilization in MRCTs.
Methods:
Seven fresh frozen cadaveric specimens were used with a customized shoulder testing system. Three testing conditions were set up: condition 1, intact rotator cuff without magnets; condition 2, an MRCT without magnets; condition 3, an MRCT with magnets. For each condition, anterior-posterior translation, superior translation, superior migration, and subacromial contact pressure were measured at 0°, 30°, and 60° of abduction. The abduction capability of condition 2 was compared with that of condition 3.
Results:
The anterior-posterior and superior translations increased in condition 2; however, they decreased compared to condition 2 when the magnets were applied (condition 3) in multiple test positions and loadings (p <0.05). Abduction capability improved significantly in condition 3 compared with that in condition 2, even for less deltoid loading (p < 0.05).
Conclusions
The magnet biomechanically played a positive role in stabilizing the shoulder joint and enabled abduction with less deltoid force in MRCTs. However, to ensure that the magnet is clinically applicable as a stabilizer for the shoulder joint, it is necessary to thoroughly verify its safety in the human body and to conduct further research on technical challenges.
4.Triglyceride-Glucose Index Predicts Future Atherosclerotic Cardiovascular Diseases: A 16-Year Follow-up in a Prospective, Community-Dwelling Cohort Study
Joon Ho MOON ; Yongkang KIM ; Tae Jung OH ; Jae Hoon MOON ; Soo Heon KWAK ; Kyong Soo PARK ; Hak Chul JANG ; Sung Hee CHOI ; Nam H. CHO
Endocrinology and Metabolism 2023;38(4):406-417
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.
5.Oral Glucose Tolerance Testing Allows Better Prediction of Diabetes in Women with a History of Gestational Diabetes Mellitus
Tae Jung OH ; Yeong Gi KIM ; Sunyoung KANG ; Joon Ho MOON ; Soo Heon KWAK ; Sung Hee CHOI ; Soo LIM ; Kyong Soo PARK ; Hak C JANG ; Joon Seok HONG ; Nam H CHO
Diabetes & Metabolism Journal 2019;43(3):342-349
BACKGROUND: We aimed to identify the postpartum metabolic factors that were associated with the development of diabetes in women with a history of gestational diabetes mellitus (GDM). In addition, we examined the role of the oral glucose tolerance test (OGTT) in the prediction of future diabetes. METHODS: We conducted a prospective study of 179 subjects who previously had GDM but did not have diabetes at 2 months postpartum. The initial postpartum examination including a 75-g OGTT and the frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed 12 months after delivery, and annual follow-up visits were made thereafter. RESULTS: The insulinogenic index (IGI30) obtained from the OGTT was significantly correlated with the acute insulin response to glucose (AIRg) obtained from the FSIVGTT. The disposition indices obtained from the OGTT and FSIVGTT were also significantly correlated. Women who progressed to diabetes had a lower insulin secretory capacity including IGI30, AIRg, and disposition indices obtained from the FSIVGTT and OGTT compared with those who did not. However, the insulin sensitivity indices obtained from the OGTT and FSIVGTT did not differ between the two groups. Multivariate logistic regression analysis showed that the 2-hour glucose and disposition index obtained from the FSIVGTT were significant postpartum metabolic risk factors for the development of diabetes. CONCLUSION: We identified a crucial role of β-cell dysfunction in the development of diabetes in Korean women with previous GDM. The 2-hour glucose result from the OGTT is an independent predictor of future diabetes. Therefore, the OGTT is crucial for better prediction of future diabetes in Korean women with previous GDM.
Diabetes Mellitus, Type 2
;
Diabetes, Gestational
;
Female
;
Follow-Up Studies
;
Glucose
;
Glucose Tolerance Test
;
Humans
;
Insulin
;
Insulin Resistance
;
Logistic Models
;
Postpartum Period
;
Pregnancy
;
Prospective Studies
;
Risk Factors
6.Nasopharyngeal Pneumococcal Carriage of Children Attending Day Care Centers in Korea: Comparison between Children Immunized with 7-valent Pneumococcal Conjugate Vaccine and Non-immunized.
Kyung Hyo KIM ; Jung Yun HONG ; Hyunju LEE ; Ga Young KWAK ; Chan Hee NAM ; Soo Young LEE ; Eunsang OH ; Jigui YU ; Moon H NAHM ; Jin Han KANG
Journal of Korean Medical Science 2011;26(2):184-190
To confirm the effect of 7-valent pneumococcal conjugate vaccine (PCV7), pneumococcal nasopharyngeal (NP) carriage was compared between vaccinated (3 + 1 doses PCV7) and non-vaccinated children. Vaccinated subjects were recruited from highly vaccinated regions (> or = 60%), Seoul and Incheon whereas control subjects were recruited from Jeju Island where vaccination rates are low (< 15%). NP swabs were obtained from 400 children aged 18-59 months. Serotype and antibiotic susceptibility was analyzed. Pneumococcal carriage rate was 18.0% (36/200) and 31.5% (63/200) for the vaccinated and control group, respectively. Among those vaccinated, 41.7% (15/36) of the serotypes were vaccine-related type (VRT: 6A, 6C, 19A) with the most common serotype 6C. The next common type was non-typable/non-capsule 30.6% (11/36) followed by non-vaccine type 16.7% (6/36) and vaccine type (VT) serotypes were found in only 11.1% (4/36). In contrast, 52.4% (33/63) of the isolates in the control group were VT. Resistance rates for penicillin and erythromycin were lower in the vaccine group (vaccine vs control; penicillin 45.2% vs 71.4%, erythromycin 74.2% vs 90.5%, P < 0.05). Multi-drug resistance was also lower in vaccinated subjects (vaccine vs control; 45.2% vs 69.8%, P < 0.05). PCV7 reduces carriage in VT which leads to replacement of pneumococci by antibiotic susceptible VRT or non-vaccine type strains.
Adult
;
Carrier State/*immunology/prevention & control
;
Child
;
*Child Day Care Centers
;
Child, Preschool
;
Humans
;
*Immunization
;
Infant
;
Male
;
Microbial Sensitivity Tests
;
Nasopharynx
;
Pneumococcal Infections/*epidemiology/immunology/*prevention & control
;
Pneumococcal Vaccines/*administration & dosage
;
Prospective Studies
;
Republic of Korea/epidemiology
;
Serotyping
;
Streptococcus pneumoniae/*isolation & purification
7.Transcatheter Arterial Embolization in Patients with Kidney Diseases: an Overview of the Technical Aspects and Clinical Indications.
Romaric LOFFROY ; Pramod RAO ; Byung Kook KWAK ; Shinichi OTA ; Ming De LIN ; Eleni LIAPI ; Jean Francois GESCHWIND
Korean Journal of Radiology 2010;11(3):257-268
Therapeutic embolization is defined as the voluntary occlusion of one or several vessels, and this is achieved by inserting material into the lumen to obtain transient or permanent thrombosis in the downstream vascular bed. There are a number of indications for this approach in urological practice, in particular for the patients with parenchymatous or vascular kidney disease. In this review, we present the different embolization techniques and the principally employed occluding agents, and then we present the principal clinical indications and we discuss other pathologies that may benefit from this non-invasive therapy. The complications, side effects and main precautions associated with this approach are also described.
Adenocarcinoma/*therapy
;
Aneurysm/therapy
;
Angiomyolipoma/*therapy
;
Embolization, Therapeutic/*methods
;
Humans
;
Kidney/injuries
;
Kidney Diseases/*therapy
;
Kidney Neoplasms/*therapy
8.Nuclear factor of activated T cells negatively regulates expression of the tumor necrosis factor receptor-related 2 gene in T cells.
Woon Ki KIM ; Ok Ju SUL ; Jung Sook KWAK ; Hye Young HUR ; Anne M LATOUR ; Beverly H KOLLER ; Byoung S KWON ; Choon Soo JEONG
Experimental & Molecular Medicine 2010;42(12):805-810
Tumor necrosis factor receptor-related 2 (TR2, HVEM or TNFRSF-14) plays an important role in immune responses, however, the mechanisms regulating its expression are unclear. To understand the control of TR2 gene expression, we studied the upstream region of the gene. Gel supershift assays revealed inducible binding of nuclear factor of activated T cells (NFAT) to a putative NFAT site within the TR2 promoter. Furthermore, cotransfection of a dominant negative NFAT construct, or siRNA for NFAT, resulted in increased expression of a TR2 reporter gene. Our findings demonstrate that NFAT negatively regulates TR2 expression in activated T cells.
Animals
;
Base Sequence
;
CD4-Positive T-Lymphocytes/metabolism
;
Cells, Cultured
;
Down-Regulation
;
Mice
;
Mice, Inbred C57BL
;
Molecular Sequence Data
;
NFATC Transcription Factors/*physiology
;
Receptors, Tumor Necrosis Factor, Member 14/*biosynthesis
;
T-Lymphocytes/*metabolism
9.Identification of novel substrates for human checkpoint kinase Chk1 and Chk2 through genome-wide screening using a consensus Chk phosphorylation motif.
Myoung Ae KIM ; Hyun Ju KIM ; Alexandra L BROWN ; Min Young LEE ; Yoe Sik BAE ; Joo In PARK ; Jong Young KWAK ; Jay H CHUNG ; Jeanho YUN
Experimental & Molecular Medicine 2007;39(2):205-212
Checkpoint kinase 1 (Chk1) and Chk2 are effector kinases in the cellular DNA damage response and impairment of their function is closely related to tumorigenesis. Previous studies revealed several substrate proteins of Chk1 and Chk2, but identification of additional targets is still important in order to understand their tumor suppressor functions. In this study, we screened novel substrates for Chk1 and Chk2 using substrate target motifs determined previously by an oriented peptide library approach. The potential candidates were selected by genome-wide peptide database searches and were examined by in vitro kinase assays. ST5, HDAC5, PGC-1alpha, PP2A PR130, FANCG, GATA3, cyclin G, Rad51D and MAD1alpha were newly identified as in vitro substrates for Chk1 and/or Chk2. Among these, HDAC5 and PGC-1alpha were further analyzed to substantiate the screening results. Immunoprecipitation kinase assay of full-length proteins and site-directed mutagenesis analysis of the target motifs demonstrated that HDAC5 and PGC-1alpha were specific targets for Chk1 and/or Chk2 at least in vitro.
Amino Acid Motifs
;
Amino Acid Sequence
;
*Consensus Sequence
;
Genome, Human/*genetics
;
Heat-Shock Proteins/chemistry/metabolism
;
Histone Deacetylases/chemistry/metabolism
;
Humans
;
Molecular Sequence Data
;
Peptide Fragments/chemistry/metabolism
;
Phosphorylation
;
Phosphoserine/metabolism
;
Protein Kinases/*metabolism
;
Protein-Serine-Threonine Kinases/*metabolism
;
Substrate Specificity
;
Transcription Factors/chemistry/metabolism
10.Clinical Application of Nutrigenomics.
Mi Sun KWAK ; Ki Baik HAHM ; H J JOUNG
Journal of the Korean Medical Association 2006;49(2):163-172
Nutritional genomics (nutrigenomics) is the application of high-throughput functional genomics technologies to nutritional science lying in the interface between the nutritional environment and genetic process. It seeks to provide a molecular genetic understanding of how common dietary nutrition affects health by altering the expression or structure of an individual's genetic makeup. On the other hand, nutrigenetics is significantly different from nutrigenomics since nutrigenetics has been used for decades in certain rare monogenic diseases such as phenylketonuria, and has the potential to provide a basis for personalized dietary recommendation based on the individual's specific genetic background in order to prevent common multifactorial disorders decades before their clinical manifestation. The human genome maps and SNP databases, together with the rapid development of tools suitable for investigating genetic and epigenetic changes in small tissue biopsies provide the means to begin the test hypothesis about the mechanisms by which diet influences disease risk including cancer directly in human subjects, could be inevitable flatforms for clinical application to achieve targeted therapy in near future.
Biopsy
;
Deception
;
Diet
;
Epigenomics
;
Genetic Processes
;
Genome
;
Genome, Human
;
Genomics
;
Hand
;
Humans
;
Molecular Biology
;
Nutrigenomics*
;
Nutritional Sciences
;
Phenylketonurias

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