Background: PM2.5 (particulate matter less than 2.5 μm) causes various health problems. Recent studies suggest that long-term exposure to PM2.5 may have a negative impact on vision. This study examined the effects of long-term exposure to concentrations of PM2.5 exceeding Korean standards on myopia prevalence. Methods: This study was conducted on adults aged 40–69 years. The PM2.5 concentrations were calculated as the 1–5-year moving averages based on the participants' residential areas. The relationships between the PM2.5 levels, categorized by the annual average concentration standard in Korea, and the prevalence of myopia were analyzed using binary logistic regression. The results were evaluated using the 95% confidence interval. Results: PM2.5 concentrations averaged over 1–3 years were not significantly associated with the prevalence of myopia. On the other hand, the prevalence of myopia was significantly higher in areas where the 4–5-year moving average PM2.5 levels exceeded the Korean standards. These findings suggest that long-term exposure to PM2.5 may have a detrimental effect on vision. Conclusions This study revealed the impact of long-term PM2.5 exposure on the prevalence of myopia, highlighting the importance of managing PM2.5 levels. Nevertheless, further cohort studies focusing on adults and in-depth research into the effects of long-term exposure will be necessary.

Background: Humans are exposed to mercury primarily in its highly toxic form, methyl mercury, which is known to have adverse effects on various organs and systems. The negative impact of mercury exposure on the growth, development, and mental health of children, from infancy to adolescence, is well-documented. However, there are no internationally standardized safe limits for mercury exposure. This study investigated the impact of dietary habits and higher body mass index (BMI) on blood mercury levels in adolescents. Methods: This study analyzed the data from the 4th Korean National Environmental Health Survey (KoNEHS) 2018–2020. The focus was on 825 middle and high school students aged 13–18 years, whose blood mercury levels were measured. A survey on dietary and lifestyle habits was also conducted. Blood mercury levels were categorized by geometric median values, and associations with overweight status and seafood consumption were examined using a generalized linear model. Results: The geometric mean blood mercury level for the entire sample was 1.37 μg/L, with levels of 1.31 μg/L in normal-weight individuals and 1.43 μg/L in overweight individuals, showing a statistically significant difference between the two groups. After adjusting for other variables, blood mercury levels were significantly associated with overweight status (estimate: 0.084; p = 0.018; 95% confidence interval [CI]: 0.015–0.153), consumption of large fish and tuna more than once a week (estimate: 0.18; p = 0.001; 95% CI: 0.077–0.284), and consumption of fish once a week or more (estimate: 0.147; p = 0.004; 95% CI: 0.043–0.250). Conclusions In adolescents, a higher BMI and an increased consumption of large fish, tuna, and fish were associated with higher blood mercury levels. Notably, a stronger association was found between large fish consumption and blood mercury levels in the overweight group. These findings suggest the need to moderate seafood consumption and establish more proactive mercury exposure standards for adolescents.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Background: This study aimed to report the short- and midterm outcomes of arthroscopic rotator cuff repair (ARCR) and reverse shoulder arthroplasty (RSA) in weight-bearing shoulders. Methods: This retrospective multicenter study included 19 cases of ARCR and 10 cases of RSA performed in weight-bearing shoulders from 2009 to 2021. In the ARCR group, postoperative 6-month magnetic resonance imaging confirmed the tendon integrity. In the RSA group, scapular notching, acromial fracture, and implant failure were assessed using plain radiographs, and complications were recorded. In both groups, preoperative and postoperative range of motion and functional scores were documented, along with subjective satisfaction and arm use for weight-bearing on the shoulders. For patients followed up for > 5 years, a midterm analysis was performed. Results: The ARCR group included 8 men and 11 women (average age, 58.8 ± 8.0 years). Initially, Patte types 1, 2, and 3 were noted in 9, 8, and 2 patients, respectively, and 4 patients exhibited full-thickness subscapularis tears. Four patients showed supraspinatus retear, and 2 patients showed subscapularis retear. Retear of any rotator cuff was observed in 5 patients (26.3%). Twelve patients were followed up for > 5 years; 11 (91.7%) used their operated arm for weight-bearing and 9 (75.0%) were satisfied. The RSA group included 5 men and 5 women (average age, 74.3 ± 7.9 years). Procedures included RSAs for cuff tear arthropathy (n = 6), osteoarthritis (n = 3), and fracture nonunion (n = 1). No cases of dislocation, prosthesis loosening, or disassociation were observed throughout the follow-up. However, 1 patient required implant removal due to infection, and 4 patients showed stage 1 scapular notching. Five patients were followed up for > 5 years, all of whom expressed satisfaction and used their operated arms for weight-bearing, despite mean forward flexion (107.5° ± 12.6°) and American Shoulder and Elbow Surgeons score (61.5 ± 5.3) being less than reported patient acceptable symptomatic state (110° and 76, respectively). Conclusions Both ARCR and RSA showed promising outcomes in terms of weight-bearing on the operated arm and subjective satisfaction at short- and midterm follow-up. Therefore, neither of these surgeries should be considered contraindicated for patients with weight-bearing shoulder conditions.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Background: This study aimed to report the short- and midterm outcomes of arthroscopic rotator cuff repair (ARCR) and reverse shoulder arthroplasty (RSA) in weight-bearing shoulders. Methods: This retrospective multicenter study included 19 cases of ARCR and 10 cases of RSA performed in weight-bearing shoulders from 2009 to 2021. In the ARCR group, postoperative 6-month magnetic resonance imaging confirmed the tendon integrity. In the RSA group, scapular notching, acromial fracture, and implant failure were assessed using plain radiographs, and complications were recorded. In both groups, preoperative and postoperative range of motion and functional scores were documented, along with subjective satisfaction and arm use for weight-bearing on the shoulders. For patients followed up for > 5 years, a midterm analysis was performed. Results: The ARCR group included 8 men and 11 women (average age, 58.8 ± 8.0 years). Initially, Patte types 1, 2, and 3 were noted in 9, 8, and 2 patients, respectively, and 4 patients exhibited full-thickness subscapularis tears. Four patients showed supraspinatus retear, and 2 patients showed subscapularis retear. Retear of any rotator cuff was observed in 5 patients (26.3%). Twelve patients were followed up for > 5 years; 11 (91.7%) used their operated arm for weight-bearing and 9 (75.0%) were satisfied. The RSA group included 5 men and 5 women (average age, 74.3 ± 7.9 years). Procedures included RSAs for cuff tear arthropathy (n = 6), osteoarthritis (n = 3), and fracture nonunion (n = 1). No cases of dislocation, prosthesis loosening, or disassociation were observed throughout the follow-up. However, 1 patient required implant removal due to infection, and 4 patients showed stage 1 scapular notching. Five patients were followed up for > 5 years, all of whom expressed satisfaction and used their operated arms for weight-bearing, despite mean forward flexion (107.5° ± 12.6°) and American Shoulder and Elbow Surgeons score (61.5 ± 5.3) being less than reported patient acceptable symptomatic state (110° and 76, respectively). Conclusions Both ARCR and RSA showed promising outcomes in terms of weight-bearing on the operated arm and subjective satisfaction at short- and midterm follow-up. Therefore, neither of these surgeries should be considered contraindicated for patients with weight-bearing shoulder conditions.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.