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.Radial Type Low-Intensity Extracorporeal Shockwave Therapy Enhances Penile Microvascular Perfusion in an Aging Rat Model: A Novel Interventional Strategy to Treat Erectile Dysfunction
Saager Tilak CHAWLA ; Jad SHAHAN ; Nolan SOUTIPAN ; Samuel Ryan SORKHI ; Yong Sun CHOI ; Woong Jin BAE ; Sae Woong KIM ; Tung-Chin HSIEH ; Mahadevan Raj RAJASEKARAN
The World Journal of Men's Health 2025;43(2):396-406
Purpose:
Physiological aging is associated with microvascular dysfunction, including in the penis, and this may contribute to age-related erectile dysfunction (ED). Low-intensity extracorporeal shockwave therapy (Li-ESWT) is a non-invasive intervention for ED, but its effect on penile microvascular function, remains unclear. Our objectives are to (i) evaluate the effect of Li-ESWT (specifically radial type ESWT [rESWT]) on penile microvascular perfusion (PMP) in aging rats, (ii) elucidate a possible mechanism, and (iii) evaluate its impact on angiogenic and smooth muscle biomarkers in cavernosal tissue.
Materials and Methods:
Male rats (n=9; 15–18 months) were anesthetized and subjected to rESWT while monitoring PMP. The nitric oxide (NO) pathway involvement was assessed by measuring the effect of rESWT on PMP following an intracavernosal injection of N(G)-nitroarginine methyl ester (L-NAME) (NO synthase inhibitor). To elucidate the cellular mechanism, another group of rats received repeated rESWT (n=4) or no treatment (n=4) three times/week for two weeks. Rats were euthanized at the end of the study and penile tissues were analyzed for angiogenic markers (vascular endothelial growth factor-A [VEGF-A], endothelial nitric oxide synthase [eNOS]) and smooth muscle content (α-actin) using immunostaining, Western blot, and quantitative polymerase chain reaction (qPCR).
Results:
rESWT resulted in more than a 2-fold increase in PMP (from 68.5 arbitrary units; 163.7 AU). L-NAME injection produced a <40%–50% decrease (185.3 to 101.0 AU) in rESWT-induced PMP response. Immunostaining revealed increased α-actin, eNOS, and VEGF-A in the cavernosum and these findings were confirmed by qPCR and Western blot results.
Conclusions
rESWT improved PMP, which may be mediated via increased VEGF expression, which stimulates the NO/cyclic guanosine monophosphate pathway, resulting in sustained PMP. rESWT devices could offer a safe, non-invasive treatment for age-related ED.
4.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.
5.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.
6.Reducing Healing Period with DDM/rhBMP-2 Grafting for Early Loading in Dental Implant Surgery
Jeong-Kui KU ; Jung-Hoon LIM ; Jung-Ah LIM ; In-Woong UM ; Yu-Mi KIM ; Pil-Young YUN
Tissue Engineering and Regenerative Medicine 2025;22(2):261-271
Background:
Traditionally, dental implants require a healing period of 4 to 9 months for osseointegration, with longer recovery times considered when bone grafting is needed. This retrospective study evaluates the clinical efficacy of demineralized dentin matrix (DDM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) during dental implant placement to expedite the osseointegration period for early loading.
Methods:
Thirty patients (17 male, 13 female; mean age 55.0 ± 8.8 years) requiring bone grafts due to implant fixture exposure (more than four threads; ≥ 3.2 mm) were included, with a total of 96 implants placed. Implants were inserted using a two-stage protocol with DDM/rhBMP-2 grafts. Early loading was initiated at two months postoperatively in the mandible and three months in the maxilla. Clinical outcomes evaluated included primary and secondary stability (implant stability quotient values), healing period, bone width, and marginal bone level assessed via cone-beam computed tomography.
Results:
All implants successfully supported final prosthetics with a torque of 50Ncm, without any osseointegration failures. The average healing period was 69.6 days in the mandible and 90.5 days in the maxilla, with significantly higher secondary stability in the mandible (80.7 ± 6.7) compared to the maxilla (73.0 ± 9.2, p < 0.001). Histological analysis confirmed new bone formation and vascularization.
Conclusion
DDM/rhBMP-2 grafting appears to significantly reduce the healing period, enabling early loading with stable and favorable clinical outcomes.
7.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.
8.Mortality and Risk Factors for Emphysematous Pyelonephritis in Korea: A Multicenter Retrospective Cohort Study
Seung-Kwon CHOI ; Jeong Woo LEE ; Seung Il JUNG ; Eu Chang HWANG ; Joongwon CHOI ; Woong Bin KIM ; Jung Sik HUH ; Jin Bong CHOI ; Yeonjoo KIM ; Jae Min CHUNG ; Ju-Hyun SHIN ; Jae Hung JUNG ; Hong CHUNG ; Sangrak BAE ; Tae-Hyoung KIM
Urogenital Tract Infection 2025;20(1):34-41
Purpose:
Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN.
Materials and Methods:
Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods.
Results:
The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%).
Conclusions
EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.
9.Association between Skeletal Muscle Mass and Ocular Perfusion Pressure in Glaucoma
Jisoo KANG ; Ji Hong KIM ; Yu Jeong KIM ; Han Woong LIM ; Jooyoung YOON ; Won June LEE
Korean Journal of Ophthalmology 2025;39(3):246-260
Purpose:
This study aimed to investigate the relationship between body composition and glaucoma by analyzing the associations between anthropometric and ocular parameters.
Methods:
A total of 494 eyes from 247 patients were reviewed from a general health examination database at a tertiary hospital. Anthropometric parameters were assessed using a multifrequency bioelectrical impedance device. Mean ocular perfusion pressure (MOPP) was calculated based on systolic and diastolic blood pressures and intraocular pressure (IOP). Retinal thickness and other ocular parameters were analyzed for their association with body composition.
Results:
A total of 221 eyes from 221 patients, including 104 with glaucoma, were enrolled in the final analysis. The prevalence of sarcopenia was significantly higher in patients with glaucomatous damage than in those without (p = 0.025). Higher IOP showed significant associations with lower MOPP (p < 0.001), higher body mass index (BMI; p = 0.001), and higher waist to hip ratio (p = 0.001). Retinal thickness was not significantly associated with body composition parameters, including BMI and appendicular lean mass adjusted with squared height. Higher MOPP was significantly correlated with lower IOP (p < 0.001), higher BMI (p < 0.001), higher waist to hip ratio (p < 0.001), and higher appendicular lean mass divided by squared height (p = 0.009).
Conclusions
Skeletal muscle mass and BMI were significantly associated with MOPP. Since low MOPP is a known risk factor for glaucoma, its association with skeletal muscle mass may indicate a relationship between systemic muscle health, ocular blood perfusion, and glaucomatous damage. Further large-scale studies are needed to validate these associations between skeletal muscle mass and glaucoma and explore their clinical implications.
10.Reinjection in Patients with Intraocular Inflammation Development after Intravitreal Brolucizumab Injection
Myung Ae KIM ; Soon Il CHOI ; Jong Min KIM ; Hyun Sub OH ; Yong Sung YOU ; Won Ki LEE ; Soon Hyun KIM ; Oh Woong KWON ; Ju Young KIM
Korean Journal of Ophthalmology 2025;39(3):213-221
Purpose:
To investigate the outcomes of brolucizumab reinjection after intraocular inflammation (IOI) development.
Methods:
This retrospective study analyzed patients with brolucizumab injections from April 2021 to January 2024. Patients who developed IOI after brolucizumab were included and categorized into subgroups depending on reinjection, discontinuation, and further IOI development.
Results:
A total of 472 eyes of 432 patients received brolucizumab injections. Thirty-eight cases developed IOI at least once, and 25 continued brolucizumab. Sixteen cases had no more IOI events, and nine experienced a second or more IOI events. Among the nine cases, three maintained brolucizumab injections despite IOI recurrence. The incidence of IOI was 8.1% based on the number of eyes (38 of 472 eyes) and 2.0% based on the number of brolucizumab injections (50 of 2,468 injections). The incidence of occlusive retinal vasculitis was 0.2% (1 of 472 eyes). The recurrence rate was 23.7% (9 of 38 eyes). The average number of injections between the first brolucizumab injection and the injection date on which IOI first developed was 2.15 times in the no-reinjection group, 3.44 times in the no-IOI-recurrence group, and 2.0 times in the second-IOI-episode group. Time to IOI occurrence in cases with first IOI episode was 18.60 ± 16.73 days, with 15 cases developing IOI within 1 week.
Conclusions
This study elucidates the real-world incidence of brolucizumab associated IOIs, with a description of information related to reinjections after the IOI episodes. A comprehensive understanding of brolucizumab reinjection is essential for its optimal utilization.

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