1.A Nomogram for End-Stage Renal Disease Prediction in Patients with Type 2 Diabetes Mellitus: A Nationwide Cohort Study in Korea
Inha JUNG ; Bong-Seong KIM ; So Young PARK ; Da Young LEE ; Ji Hee YU ; Ji A SEO ; Kyung-Do HAN ; Nan Hee KIM
Endocrinology and Metabolism 2026;41(2):245-255
Background:
Despite the rising incidence of end-stage renal disease (ESRD) among individuals with type 2 diabetes mellitus (T2DM) in Korea, no predictive model or nomogram has been developed using a nationwide cohort. In this study, we developed a nomogram to predict the long-term risk of ESRD in patients with T2DM using a large-scale, population-based Korean database.
Methods:
Using the Korean National Health Insurance Database, patients with T2DM who underwent health examinations between 2015 and 2016 were assigned as development (n=1,744,277) and validation (n=747,407) cohorts. New ESRD cases were identified using codes for renal replacement therapy. A Cox proportional hazards regression model was used to derive a risk-scoring system, and 13 variables were selected. A risk score nomogram was then created to estimate the risk of ESRD.
Results:
In the development cohort, 8,631 patients with T2DM developed ESRD during a follow-up period of 4.8±0.9 years. After multivariable adjustment, significant predictors of ESRD included male sex, current smoking, physical inactivity, low income, low body mass index, hypertension, low-density lipoprotein cholesterol ≥160 mg/dL, chronic kidney disease, insulin use, and longer duration of T2DM. A final nomogram incorporating 13 variables was developed to estimate the individual probability of ESRD. The concordance index for ESRD prediction in the validation cohort was 0.906 (95% confidence interval, 0.9 to 0.912).
Conclusion
This 13-variable nomogram provides a simple tool for identifying patients with T2DM at high risk of ESRD and may aid in early intervention.
2.Poor Prognosis of Pneumococcal Co-Infection in Hospitalized Patients with COVID-19: A Propensity Score-Matched Analysis
Soyoon HWANG ; Eunkyung NAM ; Shin-Woo KIM ; Hyun-Ha CHANG ; Yoonjung KIM ; Sohyun BAE ; Nan Young LEE ; Yu Kyung KIM ; Ji Sun KIM ; Han Wook PARK ; Joon Gyu BAE ; Juhwan JEONG ; Ki Tae KWON
Infection and Chemotherapy 2025;57(1):172-178
The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.
3.Poor Prognosis of Pneumococcal Co-Infection in Hospitalized Patients with COVID-19: A Propensity Score-Matched Analysis
Soyoon HWANG ; Eunkyung NAM ; Shin-Woo KIM ; Hyun-Ha CHANG ; Yoonjung KIM ; Sohyun BAE ; Nan Young LEE ; Yu Kyung KIM ; Ji Sun KIM ; Han Wook PARK ; Joon Gyu BAE ; Juhwan JEONG ; Ki Tae KWON
Infection and Chemotherapy 2025;57(1):172-178
The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.
4.Poor Prognosis of Pneumococcal Co-Infection in Hospitalized Patients with COVID-19: A Propensity Score-Matched Analysis
Soyoon HWANG ; Eunkyung NAM ; Shin-Woo KIM ; Hyun-Ha CHANG ; Yoonjung KIM ; Sohyun BAE ; Nan Young LEE ; Yu Kyung KIM ; Ji Sun KIM ; Han Wook PARK ; Joon Gyu BAE ; Juhwan JEONG ; Ki Tae KWON
Infection and Chemotherapy 2025;57(1):172-178
The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.
5.Raynaud’s Phenomenon: A Current Update on Pathogenesis, Diagnostic Workup, and Treatment
Hirut Yadeta TURE ; Nan Young LEE ; Na Ri KIM ; Eon Jeong NAM
Vascular Specialist International 2024;40(3):26-
Raynaud’s phenomenon (RP) is a condition characterized by episodic, excessive vasoconstriction in the fingers and toes, triggered by cold or stress. This leads to a distinctive sequence of color changes in the digits. Pallor indicates reduced blood flow due to oxygen deprivation, while erythema appears as reperfusion. RP can be primary, with no identifiable underlying cause, or secondary, associated with other conditions. These conditions include autoimmune diseases, most commonly systemic sclerosis, vascular diseases; and neurological conditions. While the exact cause of RP remains unclear, genetic and hormonal (estrogen) factors are likely contributors. The pathogenesis of RP involves a complex interaction between the vascular wall, nerves, hormones, and humoral factors, disrupting the balance between vasoconstriction and vasodilation. In primary RP, the vascular abnormalities are primarily functional. However, in secondary RP, both functional and structural components occur in blood vessels. This explains why digital tissue damage frequently occurs in secondary RP but not primary RP. Diagnosis of RP is primarily clinical. Recent advancements in imaging techniques have aided in diagnosis and monitoring, but nail fold capillaroscopy remains the gold standard for distinguishing between primary and secondary RP. If there are signs of acute ischemic injury, vascular imaging, particularly preoperatively, is crucial to rule out other vasoocclusive conditions. Management of RP focuses on alleviating symptoms and preventing tissue damage. Vasodilator medications are the first-line treatment when general measures like warmth and stress management are not sufficient. Dihydropyridine calcium channel blockers (CCBs), such as nifedipine, are commonly used for vasodilation. Phosphodiesterase-5 inhibitors and prostaglandin analogs are alternative options for patients who do not respond to CCBs or have ischemic tissue damage. Bosentan, an endothelin-1 receptor antagonist, has shown effectiveness in treating and preventing digital ulcers, especially in patients with multiple ulcers. For severe cases, botulinum toxin injections or sympathectomy surgery can be used to control RP symptoms. However, botulinum toxin injections require repeated administration, and sympathectomy’s long-term effectiveness is uncertain.Fat grafting is a promising surgical therapy for promoting healing and preventing tissue injury.
6.Risk of Death From Various Causes According to Prevalent Atrial Fibrillation: A Nationwide Population-Based Study
Young-Kwan KIM ; So-Ryoung LEE ; Eue-Keun CHOI ; Hyun Jin AHN ; Nan Young BAE ; Kyung-Yeon LEE ; JungMin CHOI ; Hyo-Jeong AHN ; Soonil KWON ; Kyungdo HAN ; Seil OH ; Gregory Y. H. LIP
Journal of Korean Medical Science 2024;39(47):e306-
Background:
Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort.
Methods:
Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model.
Results:
In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7.
Conclusion
Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.
7.Risk of Death From Various Causes According to Prevalent Atrial Fibrillation: A Nationwide Population-Based Study
Young-Kwan KIM ; So-Ryoung LEE ; Eue-Keun CHOI ; Hyun Jin AHN ; Nan Young BAE ; Kyung-Yeon LEE ; JungMin CHOI ; Hyo-Jeong AHN ; Soonil KWON ; Kyungdo HAN ; Seil OH ; Gregory Y. H. LIP
Journal of Korean Medical Science 2024;39(47):e306-
Background:
Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort.
Methods:
Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model.
Results:
In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7.
Conclusion
Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.
8.Reference Intervals for Research Parameters of Reticulocyte Hemoglobin and Platelet Clumps in Healthy Korean Adults
Miyoung KIM ; Miyoung KIM ; Sangkyoon HONG ; Sangkyoon HONG ; Nan Young KIM ; Nan Young KIM ; Kibum JEON ; Kibum JEON ; Jiwon LEE ; Jiwon LEE ; Han-Sung KIM ; Han-Sung KIM ; Hee Jung KANG ; Hee Jung KANG ; Young Kyung LEE
Journal of Laboratory Medicine and Quality Assurance 2024;46(1):38-42
Background:
Automated hematology analyzers report various research parameters. Certain parameters may have clinical implications, whereas others are used to set flags in automated hematology analyzers. In this study, we established sex-specific reference intervals for one reticulocyte parameter and two platelet clump parameters in Korean adults and examined the necessity of separate reference intervals for each sex.
Methods:
A total of 264 healthy adults (157 men and 107 women) aged between 18 and 65 years who underwent regular health check-ups were enrolled. Complete blood cell count was measured using Advia2120i (Siemens, Germany) within 4 hours of phlebotomy. Reference intervals were established according to the Clinical and Laboratory Standards Institute EP28-A3 guideline, and the necessity of separate sex-specific reference intervals was examined according to the method outlined by Harris and Boyd.
Results:
The reference intervals for each parameter were as follows:reticulocyte hemoglobin (g/L), 132.8–172.0 (men), 96.7–162.8 (women); the number of platelet clumps (# platelet clumps), 10.8–61.0 (men), -22.5–64.4 (women); and %platelet clumps, 0.20–1.49 (men), -0.57–1.53 (women).Reticulocyte hemoglobin showed a significant difference between men and women, whereas # platelet clumps and %platelet clumps did not; however, all three parameters needed separate sex-specific reference intervals.
Conclusions
We established sex-specific reference intervals for a reticulocyte parameter and platelet clumps parameters in Korean adults for the first time.The results could provide helpful information in clinical decision-making and instrument setting.
9.Metabolic Dysfunction-Associated Steatotic Liver Disease in Type 2 Diabetes Mellitus: A Review and Position Statement of the Fatty Liver Research Group of the Korean Diabetes Association
Jaehyun BAE ; Eugene HAN ; Hye Won LEE ; Cheol-Young PARK ; Choon Hee CHUNG ; Dae Ho LEE ; Eun-Hee CHO ; Eun-Jung RHEE ; Ji Hee YU ; Ji Hyun PARK ; Ji-Cheol BAE ; Jung Hwan PARK ; Kyung Mook CHOI ; Kyung-Soo KIM ; Mi Hae SEO ; Minyoung LEE ; Nan-Hee KIM ; So Hun KIM ; Won-Young LEE ; Woo Je LEE ; Yeon-Kyung CHOI ; Yong-ho LEE ; You-Cheol HWANG ; Young Sang LYU ; Byung-Wan LEE ; Bong-Soo CHA ;
Diabetes & Metabolism Journal 2024;48(6):1015-1028
Since the role of the liver in metabolic dysfunction, including type 2 diabetes mellitus, was demonstrated, studies on non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) have shown associations between fatty liver disease and other metabolic diseases. Unlike the exclusionary diagnostic criteria of NAFLD, MAFLD diagnosis is based on the presence of metabolic dysregulation in fatty liver disease. Renaming NAFLD as MAFLD also introduced simpler diagnostic criteria. In 2023, a new nomenclature, steatotic liver disease (SLD), was proposed. Similar to MAFLD, SLD diagnosis is based on the presence of hepatic steatosis with at least one cardiometabolic dysfunction. SLD is categorized into metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-related/-associated liver disease, alcoholrelated liver disease, specific etiology SLD, and cryptogenic SLD. The term MASLD has been adopted by a number of leading national and international societies due to its concise diagnostic criteria, exclusion of other concomitant liver diseases, and lack of stigmatizing terms. This article reviews the diagnostic criteria, clinical relevance, and differences among NAFLD, MAFLD, and MASLD from a diabetologist’s perspective and provides a rationale for adopting SLD/MASLD in the Fatty Liver Research Group of the Korean Diabetes Association.
10.Association of Succinate and Adenosine Nucleotide Metabolic Pathways with Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus
Inha JUNG ; Seungyoon NAM ; Da Young LEE ; So Young PARK ; Ji Hee YU ; Ji A SEO ; Dae Ho LEE ; Nan Hee KIM
Diabetes & Metabolism Journal 2024;48(6):1126-1134
Background:
Although the prevalence of diabetic kidney disease (DKD) is increasing, reliable biomarkers for its early detection are scarce. This study aimed to evaluate the association of adenosine and succinate levels and their related pathways, including hyaluronic acid (HA) synthesis, with DKD.
Methods:
We examined 235 participants and categorized them into three groups: healthy controls; those with diabetes but without DKD; and those with DKD, which was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. We compared the concentrations of urinary adenosine, succinate, and HA and the serum levels of cluster of differentiation 39 (CD39) and CD73, which are involved in adenosine generation, among the groups with DKD or albuminuria. In addition, we performed multiple logistic regression analysis to evaluate the independent association of DKD or albuminuria with the metabolites after adjusting for risk factors. We also showed the association of these metabolites with eGFR measured several years before enrollment. This study was registered with the Clinical Research Information Service (https://cris.nih.go.kr; Registration number: KCT0003573).
Results:
Urinary succinate and serum CD39 levels were higher in the DKD group than in the control and non-DKD groups. Correlation analysis consistently linked urinary succinate and serum CD39 concentrations with eGFR, albuminuria, and ΔeGFR, which was calculated retrospectively. However, among the various metabolites studied, only urinary succinate was identified as an independent indicator of DKD and albuminuria.
Conclusion
Among several potential metabolites, only urinary succinate was independently associated with DKD. These findings hold promise for clinical application in the management of DKD.

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