Sarcopenia is a major geriatric syndrome characterized by progressive loss of muscle mass and strength, resulting in disability and mortality. This narrative review synthesizes international consensus recommendations and Korean evidence to guide context-specific sarcopenia management strategies. PubMed, Embase, Cochrane Library, and KoreaMed (January 2000–November 2025) were searched, focusing on randomized trials, meta-analyses, systematic reviews, clinical practice guidelines, and large observational studies. Global diagnostic frameworks have evolved from muscle mass-based definitions toward multidimensional models that incorporate muscle strength and physical performance. Exercise and nutrition remain the mainstay treatments, with resistance-based training and adequate protein intake. Currently, pharmacologic options with proven clinical benefit are limited. In Korea, growing evidence supports the effectiveness of community-based sarcopenia interventions, underscoring the need for standardized, integrated delivery models that bridge the fragmented healthcare system and enable sustainable implementation.

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: 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: 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: 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.

Objective: The aim of the study is to evaluate the efficacy of a karaoke-based digital therapeutic program (CogniSong) in patients with mild cognitive impairment (MCI). Methods: In a 12-week single-center, assessor-blinded randomized controlled trial, 36 patients with MCI were randomly assigned to either the CogniSong digital therapeutics (DTx) group (n=18) or standard treatment group (n=18). The intervention group underwent daily 30-minute karaoke game-based cognitive training sessions via a mobile application. The primary outcome was the change in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total score from baseline to week 12. Secondary outcomes included RBANS subdomain index scores, the Seoul-Instrumental Activities of Daily Living, 17-item Hamilton Depression Rating Scale, Neuropsychiatric Inventory, and Clinical Dementia Rating–Sum of Boxes. Results: The DTx group showed a significantly greater improvement in RBANS total score compared to standard treatment group (mean change +5.9 points vs. -0.2 points, p=0.041). However, there were no significant between-group differences in RBANS subdomain scores or secondary outcomes such as daily functioning, mood, neuropsychiatric symptoms, or global clinical status. Conclusion In this randomized controlled trial, a karaoke-based DTx appeared feasible and effective in enhancing global cognition in MCI. The findings support its potential as a complementary intervention for cognitive improvement in MCI patients.

Sarcopenia, which is characterized by an age-related decline in muscle mass and function, poses significant challenges to geriatric care. Its definition has evolved from muscle-specific criteria to include muscle mass, muscle function, and physical performance, recognizing sarcopenia as a physical frailty. Sarcopenia is associated with adverse outcomes, including mortality, falls, fractures, cognitive decline, and admission to long-term care facilities. Neuromechanical factors, protein-energy balance, and muscle protein synthesis-breakdown mechanisms contribute to its pathophysiology. The identification of sarcopenia involves screening tests and a comprehensive assessment of muscle mass, strength, and physical function. Clinical approaches aligned with the principles of comprehensive geriatric assessment prioritize patient-centered care. This assessment aids in identifying issues related to activities of daily living, cognition, mood, nutrition, and social support, alongside other aspects. The general approach to factors underlying muscle loss and functional decline in patients with sarcopenia includes managing chronic diseases and evaluating administered medications, with interventions including exercise and nutrition, as well as evolving pharmacological options. Ongoing research targeting pathways, such as myostatin-activin and exercise mimetics, holds promise for pharmacological interventions. In summary, sarcopenia requires a multifaceted approach, acknowledging its complex etiology and tailoring interventions to individual patient needs.

Background: South Korea faces a critical challenge with its rapidly declining fertility rates and an increasingly aging population, which significantly impacts the country's blood supply and demand. Despite these nationwide trends, regional disparities in blood supply and demand have not been thoroughly studied. Methods: This research utilized blood donation data from the Korean Red Cross and blood transfusion data from the Health Insurance Review and Assessment Service. We analyzed these datasets in conjunction with regional population projections to simulate blood supply and demand from 2021 to 2050 across South Korea. Sensitivity analyses were conducted to assess the impact of various factors, including the number of donors, age eligibility criteria for donations, frequency of donations, and blood discard rates. Results: Our projections indicate a decreasing trend in blood supply, from 2.6 million units in 2021 to 1.4 million units by 2050, while demand is expected to peak at 5.1 million units by 2045 before declining. Metropolitan areas, particularly Gyeonggi Province, are projected to experience the most severe shortages. Sensitivity analyses suggest that increasing the donation frequency of existing donors and relaxing age eligibility criteria are more effective strategies in addressing these imbalances than merely increasing the number of new donors. Blood discard rates showed minimal impact on the overall blood shortage. Conclusion The findings emphasize the urgent need for targeted strategies to mitigate national and regional blood supply shortages in South Korea. Encouraging frequent donations from experienced donors and broadening eligibility criteria are critical steps toward stabilizing the blood supply amidst demographic shifts. These strategies must be prioritized to address the impending regional disparities in blood availability.

Background/Aims: The recent coronavirus disease 2019 (COVID-19) pandemic has been associated with changes in the epidemiology of not only infectious diseases but also several non-infectious conditions. This study investigated changes in the recorded incidence of various rheumatic diseases during the COVID-19 pandemic. Methods: The number of patients for each disease from January 2016 to December 2020 was obtained from the Korean Health Insurance Review and Assessment Service database. We compared the incidence of nine rheumatic diseases (seropositive rheumatoid arthritis, systemic lupus erythematosus [SLE], idiopathic inflammatory myositis [IIM], ankylosing spondylitis [AS], systemic sclerosis, Sjögren’s syndrome, Behçet’s disease [BD], polymyalgia rheumatica, and gout) and hypertensive diseases to control for changes in healthcare utilisation before and after the COVID-19 outbreak. The disease incidence before and after the COVID-19 outbreak was compared using the autoregressive integrated moving average (ARIMA) and quasi- Poisson analyses. Results: Compared with the predicted incidence in 2020 using the ARIMA model, the monthly incidence of SLE, BD, AS, and gout temporarily significantly decreased, whereas other rheumatic diseases and hypertensive diseases were within the 95% confidence interval (CI) of the predicted values in the first half of 2020. In age- and sex-adjusted quasi-Poisson regression analysis, the annual incidences of IIM (rate ratio [RR], 0.473; 95% CI, 0.307 to 0.697), SLE (RR, 0.845; 95% CI, 0.798 to 0.895), and BD (RR, 0.850; 95% CI, 0.796 to 0.906) were significantly decreased compared with those in the previous 4 years. Conclusions The recorded annual incidence of some rheumatic diseases, including IIM, SLE, and BD, decreased during the COVID-19 pandemic.

Background: Despite the protective effects of stromal cell-derived factor 1 (SDF-1) in stimulating muscle regeneration shown in experimental research, there is a lack of clinical studies linking circulating SDF-1 concentrations with muscle phenotypes. In order to elucidate the role of SDF-1 as a potential biomarker reflecting human muscle health, we investigated the association of plasma SDF-1 levels with sarcopenia in older adults. Methods: This cross-sectional study included 97 community-dwelling participants who underwent a comprehensive geriatric assessment at a tertiary hospital in South Korea. Sarcopenia was defined by specific cutoff values applicable to the Asian population, whereas plasma SDF-1 levels were determined using an enzyme immunoassay. Results: After accounting for sex, age, and body mass index, participants with sarcopenia and low muscle mass exhibited plasma SDF-1 levels that were 21.8% and 18.3% lower than those without these conditions, respectively (P=0.008 and P=0.009, respectively). Consistently, higher plasma SDF-1 levels exhibited a significant correlation with higher skeletal muscle mass index (SMI) and gait speed (both P=0.043), and the risk of sarcopenia and low muscle mass decreased by 58% and 55% per standard deviation increase in plasma SDF-1 levels, respectively (P=0.045 and P=0.030, respectively). Furthermore, participants in the highest SDF-1 tertile exhibited significantly higher SMI compared to those in the lowest tertile (P=0.012). Conclusion These findings clinically corroborate earlier experimental discoveries highlighting the muscle anabolic effects of SDF- 1 and support the potential role of circulating SDF-1 as a biomarker reflecting human muscle health in older adults.