1.A Pilot Study Examining If the Additional Use of a Continuous Glucose Monitoring Is Helpful for Glucose Control in Older Adults
Kwang Joon KIM ; Yang Sun PARK ; Eunseo SUN ; Euna JO ; Jiwon SHINN ; Hyeon Woo YIM ; Chang Oh KIM ; Hun-Sung KIM
Yonsei Medical Journal 2025;66(6):346-353
Purpose:
To investigate whether using a continuous glucose monitoring (CGM) for the second time (2nd_CGM) would be effective after using it for the first time (1st_CGM), depending on age.
Materials and Methods:
This study included patients aged ≥40 years who were diagnosed with type 2 diabetes and had used a CGM at least twice between 2017 and 2021. Participants were divided into two groups based on their age: those aged <60 years and those aged ≥60 years. We assessed the glycemic control status of the 1st_CGM and 2nd_CGM, along with the glycemic variability.
Results:
Overall, 15 patients were included in the study. The mean glucose level in users aged <60 years significantly decreased (p<0.001) owing to the CGM use, while it did not increase in those aged ≥60 years. In users aged ≥60 years, the 1st_CGM group showed a significant decrease in blood glucose levels over time (p<0.05), whereas the 2nd_CGM group only showed a non-significant decreasing trend. The time in range tended to increase in those aged <60 years but decreased in those aged ≥60 years. In those aged <60 years, the mean amplitude of glycemic excursions (p<0.001), standard deviation (p<0.05), and coefficient of variation (p<0.001) significantly decreased. In those aged ≥60 years, these parameters exhibited a non-significant decreasing trend.
Conclusion
Glycemic effect and variability improved as expected with 1st_CGM use. However, 2nd_CGM did not significantly improve glycemic effect or variability in users aged ≥60 years, contrary to expectations. To address this issue, further investigation is needed to understand why, compared to 1st_CGM, 2nd_CGM fails to achieve better glycemic control in individuals aged ≥60 years.
2.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
3.Pre-Treatment Perceived Social Support Is Associated With Chemotherapy-Induced Peripheral Neuropathy in Patients With Breast Cancer: A Longitudinal Study
Joon Sung SHIN ; Sanghyup JUNG ; Geun Hui WON ; Sun Hyung LEE ; Jaehyun KIM ; Saim JUNG ; Chan-Woo YEOM ; Kwang-Min LEE ; Kyung-Lak SON ; Jang-il KIM ; Sook Young JEON ; Han-Byoel LEE ; Bong-Jin HAHM
Psychiatry Investigation 2025;22(4):424-434
Objective:
Previous studies have reported an association between cancer-related symptoms and perceived social support (PSS). The objective of this study was to analyze whether Chemotherapy-Induced Peripheral Neuropathy (CIPN), a prevalent side effect of chemotherapy, varies according to PSS level using a validated tool for CIPN at prospective follow-up.
Methods:
A total of 39 breast cancer patients were evaluated for PSS using the Multidimensional Scale of Perceived Social Support (MSPSS) prior to chemotherapy and were subsequently grouped into one of two categories for each subscale: low-to-moderate PSS and high PSS. CIPN was prospectively evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy 20 (CIPN20) at five time points. A linear mixed-effects model with square root transformation was employed to investigate whether the CIPN20 scales varied by PSS level and time point.
Results:
Statistical analysis of the MSPSS total scale and subscales revealed a significant effect of the friends subscale group and time point on the CIPN20 sensory scale. The sensory scale score of CIPN20 was found to be lower in participants with high PSS from friends in comparison to those with low-to-moderate PSS at 1 month post-chemotherapy (p=0.010).
Conclusion
This is the first study to prospectively follow the long-term effect of pre-treatment PSS from friends on CIPN. Further studies based on larger samples are required to analyze the effects of PSS on the pathophysiology of CIPN.
4.Clinical Significance of Various Pathogens Identified in Patients Experiencing Acute Exacerbations of COPD: A Multi-center Study in South Korea
Hyun Woo JI ; Soojoung YU ; Yun Su SIM ; Hyewon SEO ; Jeong-Woong PARK ; Kyung Hoon MIN ; Deog Kyeom KIM ; Hyun Woo LEE ; Chin Kook RHEE ; Yong Bum PARK ; Kyeong-Cheol SHIN ; Kwang Ha YOO ; Ji Ye JUNG
Tuberculosis and Respiratory Diseases 2025;88(2):292-302
Background:
Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD.
Methods:
This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests.
Results:
Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030).
Conclusion
This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.
5.A Pilot Study Examining If the Additional Use of a Continuous Glucose Monitoring Is Helpful for Glucose Control in Older Adults
Kwang Joon KIM ; Yang Sun PARK ; Eunseo SUN ; Euna JO ; Jiwon SHINN ; Hyeon Woo YIM ; Chang Oh KIM ; Hun-Sung KIM
Yonsei Medical Journal 2025;66(6):346-353
Purpose:
To investigate whether using a continuous glucose monitoring (CGM) for the second time (2nd_CGM) would be effective after using it for the first time (1st_CGM), depending on age.
Materials and Methods:
This study included patients aged ≥40 years who were diagnosed with type 2 diabetes and had used a CGM at least twice between 2017 and 2021. Participants were divided into two groups based on their age: those aged <60 years and those aged ≥60 years. We assessed the glycemic control status of the 1st_CGM and 2nd_CGM, along with the glycemic variability.
Results:
Overall, 15 patients were included in the study. The mean glucose level in users aged <60 years significantly decreased (p<0.001) owing to the CGM use, while it did not increase in those aged ≥60 years. In users aged ≥60 years, the 1st_CGM group showed a significant decrease in blood glucose levels over time (p<0.05), whereas the 2nd_CGM group only showed a non-significant decreasing trend. The time in range tended to increase in those aged <60 years but decreased in those aged ≥60 years. In those aged <60 years, the mean amplitude of glycemic excursions (p<0.001), standard deviation (p<0.05), and coefficient of variation (p<0.001) significantly decreased. In those aged ≥60 years, these parameters exhibited a non-significant decreasing trend.
Conclusion
Glycemic effect and variability improved as expected with 1st_CGM use. However, 2nd_CGM did not significantly improve glycemic effect or variability in users aged ≥60 years, contrary to expectations. To address this issue, further investigation is needed to understand why, compared to 1st_CGM, 2nd_CGM fails to achieve better glycemic control in individuals aged ≥60 years.
6.Clinical Efficacy of Intense Pulsed Light Therapy in Treating Meibomian Gland Dysfunction among Glaucoma Patients
Kwang Eon HAN ; Sang Woo MOON ; Su Jin KIM ; Ji Eun LEE
Journal of the Korean Ophthalmological Society 2025;66(5):215-223
Purpose:
To evaluate the clinical efficacy of intense pulsed light (IPL) therapy combined with meibomian gland expression (MGX) in treating meibomian gland dysfunction (MGD) caused by glaucoma eye drops.
Methods:
This study included 20 patients (aged 18-85 years) who were using glaucoma eye drops and exhibited signs of MGD. Participants underwent four sessions of IPL therapy at 3-week intervals, each followed by MGX. Evaluative measures included the Ocular Surface Disease Index (OSDI), best-corrected visual acuity, Schirmer's test, tear break-up time (TBUT), corneal fluorescein staining score (CFS), lid margin abnormalities, meibomian gland expressibility (MGE), meibum quality, lipid layer thickness (LLT), and meiboscore. These assessments were conducted before and after each treatment.
Results:
After treatment, significant improvements were observed across all measured parameters, including OSDI, Schirmer's test, TBUT, CFS, lid margin abnormalities, MGE, meibum quality, LLT, and meiboscore.
Conclusions
IPL therapy combined with MGX was effective in improving ocular surface and eyelid abnormalities among patients with MGD induced by glaucoma eye drops. Our findings support the use of IPL and MGX as safe and effective adjunct therapies for these patients.
7.Risk Factors of FEV 1 /FVC Decline in COPD Patients
Na Young KIM ; Deog Kyeom KIM ; Shinhee PARK ; Yong Il HWANG ; Hyewon SEO ; Dongil PARK ; Seoung Ju PARK ; Jin Hwa LEE ; Kwang Ha YOO ; Hyun Woo LEE
Journal of Korean Medical Science 2025;40(6):e32-
Background:
Factors influencing the decline in forced expiratory volume in one second (FEV1 )/forced vital capacity (FVC) for chronic obstructive pulmonary disease (COPD) progression remain uncertain. We aimed to identify risk factors associated with rapid FEV1 / FVC decline in patients with COPD.
Methods:
This multi-center observational study was conducted from January 2012 to December 2022. Eligible patients were monitored with symptoms, spirometric tests, and treatment patterns over 3 years. Rapid FEV1 /FVC decliners were defined as the quartile of patients exhibiting the highest annualized percentage decline in FEV1 /FVC.
Results:
Among 1,725 patients, 435 exhibited rapid FEV1 /FVC decline, with an annual change of −2.5%p (interquartile range, −3.5 to −2.0). Rapid FEV1 /FVC decliners exhibited lower body mass index (BMI), higher smoking rates, elevated post-bronchodilator (BD) FEV1 , higher post-BD FEV1 / FVC, and a lower prevalence of Staging of Airflow Obstruction by Ratio (STAR) stage IV. Rapid FEV1 /FVC decline was not linked to the annual exacerbation rate, but there was an association with symptom deterioration and FEV1 decline. In multivariable analyses, low BMI, current smoking, increased modified Medical Research Council dyspnoea score, low post-BD FEV1 , low STAR stage, high forced mid-expiratory flow (FEF 25-75% ), accelerated FEV1 decline, and not initiating dual BD therapy were identified as independent risk factors for rapid FEV1 /FVC decline.
Conclusion
We identified the risk factors for rapid FEV1 /FVC decline, including BMI, smoking, symptoms deterioration, FEV1 decline, and adherence to standard inhaler treatment. Our findings underscore the potential benefits of maintaining consistent use of long-acting beta-agonist/long-acting muscarinic antagonist even in the presence of worsening symptoms, in attenuating FEV1 /FVC decline.
8.Risk Factors of FEV 1 /FVC Decline in COPD Patients
Na Young KIM ; Deog Kyeom KIM ; Shinhee PARK ; Yong Il HWANG ; Hyewon SEO ; Dongil PARK ; Seoung Ju PARK ; Jin Hwa LEE ; Kwang Ha YOO ; Hyun Woo LEE
Journal of Korean Medical Science 2025;40(6):e32-
Background:
Factors influencing the decline in forced expiratory volume in one second (FEV1 )/forced vital capacity (FVC) for chronic obstructive pulmonary disease (COPD) progression remain uncertain. We aimed to identify risk factors associated with rapid FEV1 / FVC decline in patients with COPD.
Methods:
This multi-center observational study was conducted from January 2012 to December 2022. Eligible patients were monitored with symptoms, spirometric tests, and treatment patterns over 3 years. Rapid FEV1 /FVC decliners were defined as the quartile of patients exhibiting the highest annualized percentage decline in FEV1 /FVC.
Results:
Among 1,725 patients, 435 exhibited rapid FEV1 /FVC decline, with an annual change of −2.5%p (interquartile range, −3.5 to −2.0). Rapid FEV1 /FVC decliners exhibited lower body mass index (BMI), higher smoking rates, elevated post-bronchodilator (BD) FEV1 , higher post-BD FEV1 / FVC, and a lower prevalence of Staging of Airflow Obstruction by Ratio (STAR) stage IV. Rapid FEV1 /FVC decline was not linked to the annual exacerbation rate, but there was an association with symptom deterioration and FEV1 decline. In multivariable analyses, low BMI, current smoking, increased modified Medical Research Council dyspnoea score, low post-BD FEV1 , low STAR stage, high forced mid-expiratory flow (FEF 25-75% ), accelerated FEV1 decline, and not initiating dual BD therapy were identified as independent risk factors for rapid FEV1 /FVC decline.
Conclusion
We identified the risk factors for rapid FEV1 /FVC decline, including BMI, smoking, symptoms deterioration, FEV1 decline, and adherence to standard inhaler treatment. Our findings underscore the potential benefits of maintaining consistent use of long-acting beta-agonist/long-acting muscarinic antagonist even in the presence of worsening symptoms, in attenuating FEV1 /FVC decline.
9.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
10.Pre-Treatment Perceived Social Support Is Associated With Chemotherapy-Induced Peripheral Neuropathy in Patients With Breast Cancer: A Longitudinal Study
Joon Sung SHIN ; Sanghyup JUNG ; Geun Hui WON ; Sun Hyung LEE ; Jaehyun KIM ; Saim JUNG ; Chan-Woo YEOM ; Kwang-Min LEE ; Kyung-Lak SON ; Jang-il KIM ; Sook Young JEON ; Han-Byoel LEE ; Bong-Jin HAHM
Psychiatry Investigation 2025;22(4):424-434
Objective:
Previous studies have reported an association between cancer-related symptoms and perceived social support (PSS). The objective of this study was to analyze whether Chemotherapy-Induced Peripheral Neuropathy (CIPN), a prevalent side effect of chemotherapy, varies according to PSS level using a validated tool for CIPN at prospective follow-up.
Methods:
A total of 39 breast cancer patients were evaluated for PSS using the Multidimensional Scale of Perceived Social Support (MSPSS) prior to chemotherapy and were subsequently grouped into one of two categories for each subscale: low-to-moderate PSS and high PSS. CIPN was prospectively evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy 20 (CIPN20) at five time points. A linear mixed-effects model with square root transformation was employed to investigate whether the CIPN20 scales varied by PSS level and time point.
Results:
Statistical analysis of the MSPSS total scale and subscales revealed a significant effect of the friends subscale group and time point on the CIPN20 sensory scale. The sensory scale score of CIPN20 was found to be lower in participants with high PSS from friends in comparison to those with low-to-moderate PSS at 1 month post-chemotherapy (p=0.010).
Conclusion
This is the first study to prospectively follow the long-term effect of pre-treatment PSS from friends on CIPN. Further studies based on larger samples are required to analyze the effects of PSS on the pathophysiology of CIPN.

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