1.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
2.Clinical outcomes of esophageal squamous cell carcinoma in patients aged over 80 years
Dae Gon RYU ; Cheol Woong CHOI ; Su Jin KIM ; Su Bum PARK ; Jin Ook JANG ; Bong Soo SON
The Korean Journal of Internal Medicine 2025;40(2):230-242
Background/Aims:
The clinical outcomes and optimal treatment of esophageal squamous cell carcinoma (ESCC) in elderly patients are unclear. This study aimed to assess the clinical outcomes of ESCC in patients aged ≥ 80 years.
Methods:
Medical records of patients diagnosed with ESCC between December 2008 and February 2024 were retrospectively reviewed. In total, 479 patients with ESCC were included and divided into the elderly (n = 52) and younger (n = 427) groups based on age. The clinical outcomes and survival rates, according to treatment, were compared between the two groups.
Results:
The median ages of the two groups were 82 years (range, 80–95 yr) and 66 years (41–79 yr). The overall survival was slightly lower in the elderly group; however, no statistical significance (hazard ratio [HR] 1.27, 95% confidence interval [CI] 0.85−1.91; p = 0.238) was observed. No differences were observed in the outcomes or survival between the two groups according to the treatment method (surgery, chemoradiotherapy or radiotherapy alone, and endoscopic resection). The elderly group was more likely to receive no treatment for cancer (30.8% vs. 13.6%, p = 0.002) than the younger group. However, when there was no treatment for cancer in the elderly group, survival was significantly lower than when treatment was administered (HR 0.08, 95% CI 0.03−020; p < 0.001).
Conclusions
In patients with ESCC aged ≥ 80 years, active cancer treatment was beneficial, and the results did not differ from those of younger patients.
3.Comparison of Finasteride and Dutasteride on Risk of Prostate Cancer in Patients with Benign Prostatic Hyperplasia: A Pooled Analysis of 15Real-world Databases
Dae Yul YANG ; Won-Woo SEO ; Rae Woong PARK ; Sang Youl RHEE ; Jae Myung CHA ; Yoon Soo HAH ; Chang Won JEONG ; Kyung-Jin KIM ; Hyeon-Jong YANG ; Do Kyung KIM ; Ji Yong HA
The World Journal of Men's Health 2025;43(1):188-196
Purpose:
Finasteride and dutasteride are used to treat benign prostatic hyperplasia (BPH) and reduce the risk of developing prostate cancer. Finasteride blocks only the type 2 form of 5-alpha-reductase, whereas dutasteride blocks both type 1 and 2 forms of the enzyme. Previous studies suggest the possibility that dutasteride may be superior to finasteride in preventing prostate cancer. We directly compared the effects of finasteride and dutasteride on the risk of prostate cancer in patients with BPH using a pooled analysis of 15 real-world databases.
Materials and Methods:
We conducted a multicenter, cohort study of new-users of finasteride and dutasteride. We include patients who were prescribed 5 mg finasteride or dutasteride for the first time to treat BPH and had at least 180 days of prescription. We excluded patients with a history of prostate cancer or a prostate-specific antigen level ≥ 4 ng/mL before the study drug prescription. Cox regression analysis was performed to examine the hazard ratio (HR) for prostate cancer after propensity score (PS) matching.
Results:
A total of 8,284 patients of new-users of finasteride and 8,670 patients of new-users of dutasteride were included across the 15 databases. In the overall population, compared to dutasteride, finasteride was associated with a lower risk of prostate cancer in both on-treatment and intent-to-treat time-at-risk periods. After 1:1 PS matching, 4,897 patients using finasteride and 4,897 patients using dutasteride were enrolled in the present study. No significant differences were observed for risk of prostate cancer between finasteride and dutasteride both on-treatment (HR=0.66, 95% confidence interval [CI]: 0.44–1.00; p=0.051) and intent-to-treat time-at-risk periods (HR=0.87, 95% CI: 0.67–1.14; p=0.310).
Conclusions
Using real-world databases, the present study demonstrated that dutasteride was not associated with a lower risk of prostate cancer than finasteride in patients with BPH.
4.Cannabidiol Alleviates Chronic Prostatitis and Chronic Pelvic Pain Syndrome via CB2 Receptor Activation and TRPV1 Desensitization
Jun Jie PIAO ; Soomin KIM ; Dongho SHIN ; Hwa Jong LEE ; Kyung-Hwa JEON ; Wen Jie TIAN ; Kyung Jae HUR ; Jong Soo KANG ; Hyun-Je PARK ; Joo Young CHA ; Aeri SONG ; Sang-Hyuck PARK ; Mahadevan RAJASEKARAN ; Woong Jin BAE ; Sungjoo KIM YOON ; Sae Woong KIM
The World Journal of Men's Health 2025;43(1):228-238
Purpose:
This study elucidates the mechanism of the physiological effect of cannabidiol (CBD) by assessing its impact on lipopolysaccharide (LPS)-induced inflammation in RWPE-1 cells and prostatitis-induced by 17β-estradiol and dihydrotestosterone in a rat model, focusing on its therapeutic potential for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).
Materials and Methods:
RWPE-1 cells were stratified in vitro into three groups: (1) controls, (2) cells with LPS-induced inflammation, and (3) cells with LPS-induced inflammation and treated with CBD. Enzyme-linked immunosorbent assays and western blots were performed on cellular components and supernatants after administration of CBD. Five groups of six Sprague–Dawley male rats were assigned: (1) control, (2) CP/CPPS, (3) CP/CPPS and treated with 50 mg/kg CBD, (4) CP/CPPS and treated with 100 mg/kg CBD, and (5) CP/CPPS and treated with 150 mg/kg CBD. Prostatitis was induced through administration of 17β-estradiol and dihydrotestosterone. After four weeks of CBD treatment, a pain index was evaluated, and prostate tissue was collected for subsequent histologic examination and western blot analysis.
Results:
CBD demonstrated efficacy in vivo for CP/CPPS and in vitro for inflammation. It inhibited the toll-like receptor 4 (TLR4)uclear factor-kappa B (NF-κB) pathway by activating the CB2 receptor, reducing expression of interleukin-6, tumor necrosis factor-alpha, and cyclooxygenase-2 (COX2) (p<0.01). CBD exhibited analgesic effects by activating and desensitizing the TRPV1 receptor.
Conclusions
CBD inhibits the TLR4/NF-κB pathway by activating the CB2 receptor, desensitizes the TRPV1 receptor, and decreases the release of COX2. This results in relief of inflammation and pain in patients with CP/CPPS, indicating CBD as a potential treatment for CP/CPPS.
5.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.
6.Validation of Devices for the Five Times Sit To Stand Test:Comparing Plantar Pressure and Head Motion Analysis with Manual Measurement
Sanghyun JEE ; Chan Woong JANG ; Kyoungmin PARK ; Sanghoon SHIN ; Min-Chul PAEK ; Jung Hyun PARK
Yonsei Medical Journal 2025;66(1):51-57
Purpose:
This study aims to evaluate a new method for the five times sit to stand test (FTSST), crucial for addressing frailty in an aging population. It utilizes a smart insole for plantar pressure analysis and a marker-less motion capture device for head height analysis.
Materials and Methods:
Thirty-five participants aged 50 years or older underwent FTSST assessment using three methods: manual measurement with a stopwatch (FTSST-M), plantar pressure analysis with smart insoles (FTSST-P), and head height analysis with a marker-less motion capture device (FTSST-H). Simultaneous measurements using three methods were done. Correlation between results of these methods were analyzed using intraclass correlation coefficient (ICC) and κ coefficient. Comprehensive clinical examinations were conducted with ethical approval.
Results:
Participants’ mean scores for FTSST-M, FTSST-P, and FTSST-H were 2.43±1.20, 2.43±1.29, and 2.37±1.31, respectively. Correlations of the times and corresponding scores between FTSST-P and FTSST-M, as well as FTSST-H and FTSST-M, exceeded 0.9 (ICC and κ coefficients, p<0.001). Using an FTSST score of 3 or less to indicate vulnerability, the κ value for vulnerability classification between two measurements was 0.886 (p<0.001).
Conclusion
This study showed strong correlation between FTSST results using smart insoles and marker-less motion capture, compared to conventional methods. These findings highlight the potential of these technologies for precise FTSST measurements, offering convenience and cost-effectiveness. Simultaneous use of these devices enables diverse analyses, enhancing our understanding of frailty.
7.Exploring methylation signatures for high de novo recurrence risk in hepatocellular carcinoma
Da-Won KIM ; Jin Hyun PARK ; Suk Kyun HONG ; Min-Hyeok JUNG ; Ji-One PYEON ; Jin-Young LEE ; Kyung-Suk SUH ; Nam-Joon YI ; YoungRok CHOI ; Kwang-Woong LEE ; Young-Joon KIM
Clinical and Molecular Hepatology 2025;31(2):563-576
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits high de novo recurrence rates post-resection. Current post-surgery recurrence prediction methods are limited, emphasizing the need for reliable biomarkers to assess recurrence risk. We aimed to develop methylation-based markers for classifying HCC patients and predicting their risk of de novo recurrence post-surgery.
Methods:
In this retrospective cohort study, we analyzed data from HCC patients who underwent surgical resection in Korea, excluding those with recurrence within one year post-surgery. Using the Infinium Methylation EPIC array on 140 samples in the discovery cohort, we classified patients into low- and high-risk groups based on methylation profiles. Distinctive markers were identified through random forest analysis. These markers were validated in the cancer genome atlas (n=217), Validation cohort 1 (n=63) and experimental Validation using a methylation-sensitive high-resolution melting (MS-HRM) assay in Validation cohort 1 and Validation cohort 2 (n=63).
Results:
The low-risk recurrence group (methylation group 1; MG1) showed a methylation average of 0.73 (95% confidence interval [CI] 0.69–0.77) with a 23.5% recurrence rate, while the high-risk group (MG2) had an average of 0.17 (95% CI 0.14–0.20) with a 44.1% recurrence rate (P<0.03). Validation confirmed the applicability of methylation markers across diverse populations, showing high accuracy in predicting the probability of HCC recurrence risk (area under the curve 96.8%). The MS-HRM assay confirmed its effectiveness in predicting de novo recurrence with 95.5% sensitivity, 89.7% specificity, and 92.2% accuracy.
Conclusions
Methylation markers effectively classified HCC patients by de novo recurrence risk, enhancing prediction accuracy and potentially offering personalized management strategies.
8.Reliability of Ultrasound Elastography According to Experience Level and Anatomic Location
Seul-Gi KIM ; Bongkyung PARK ; Kyosun HWANG ; Woong Kyo JEONG
Clinics in Orthopedic Surgery 2025;17(1):166-173
Background:
Strain elastography (SE) and shear wave elastography (SWE) are emerging techniques for evaluating the elasticity of soft tissue. This study aimed to determine interobserver and intraobserver reliability for elasticity measurements of different tissues and anatomic locations using SE and SWE.
Methods:
Ten healthy adult male individuals with 20 upper extremities participated in this study. The elasticities of the wrist extensor muscle, the common extensor tendon, and supraspinatus tendon were measured. Strain ratio and shear wave velocity were measured twice by 2 different examiners (examiner 1 with over 20 years of experience in musculoskeletal sonography and examiner 2 with 1 year of experience). Interobserver and intraobserver reliability was assessed using the intraclass correlation coefficient (ICC).
Results:
The 10 individuals’ age ranged from 28 to 35 years. In SE, interobserver reliabilities at the 3 anatomic locations (wrist extensor muscle, common extensor tendon, and supraspinatus tendon) showed fair to moderate agreement (ICC = 0.489, p = 0.076;ICC = 0.408, p = 0.131; and ICC = 0.296, p = 0.711, respectively). The intraobserver reliabilities of examiner 1 were moderate to substantial only at the wrist extensor muscle and the common extensor tendon (ICC = 0.563, p = 0.039 and ICC = 0.702, p = 0.006, respectively). In SWE, interobserver reliabilities for the wrist extensor muscle and the supraspinatus tendon were moderate to substantial (ICC = 0.756, p = 0.002 and ICC = 0.565, p = 0.039, respectively). The intraobserver reliabilities of examiner 1 at the 3 anatomic locations were almost perfect (ICC = 0.843, p = 0.001; ICC = 0.800, p = 0.001; and ICC = 0.825, p = 0.001, respectively).The results of examiner 2 showed almost perfect agreement at the wrist extensor muscle (ICC = 0.886, p = 0.001) and moderate to substantial agreement at the tendons of the common extensor and supraspinatus (ICC = 0.592, p = 0.029 and ICC = 0.682, p = 0.008, respectively).
Conclusions
SWE is a reliable method for assessing the flexibility of soft tissue, but it is affected by expertise and the specific anatomical site.
9.Korean Registry on the Current Management of Helicobacter pylori (K-Hp-Reg): Interim Analysis of Adherence to the Revised Evidence-Based Guidelines for First-Line Treatment
Hyo-Joon YANG ; Joon Sung KIM ; Ji Yong AHN ; Ok-Jae LEE ; Gwang Ha KIM ; Chang Seok BANG ; Moo In PARK ; Jae Yong PARK ; Sun Moon KIM ; Su Jin HONG ; Joon Hyun CHO ; Shin Hee KIM ; Hyun Joo SONG ; Jin Woong CHO ; Sam Ryong JEE ; Hyun LIM ; Yong Hwan KWON ; Ju Yup LEE ; Seong Woo JEON ; Seon-Young PARK ; Younghee CHOE ; Moon Kyung JOO ; Dae-Hyun KIM ; Jae Myung PARK ; Beom Jin KIM ; Jong Yeul LEE ; Tae Hoon OH ; Jae Gyu KIM ;
Gut and Liver 2025;19(3):364-375
Background/Aims:
The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea.
Methods:
This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form.
Results:
A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001).
Conclusions
The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.
10.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.

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