Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly. Methods: We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease. Results: During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001). Conclusion In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.

Background: This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea. Methods: Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB. Results: Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB. Conclusion Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.

Background: In Korea, the patterns of prevalence of gynecological cancers have shifted due to rising obesity-related cancer cases. We evaluated the associations of body mass index (BMI) and waist circumference (WC) with the risk of gynecological malignancy in Korean women. Methods: Using National Health Insurance Service cohort data, we analyzed 365,581 participants among the 1,999,980 women aged ≥ 19 years who underwent health check-ups at the baseline year 2009–2010, excluding those who died, those with prior cancer diagnoses, underwent hysterectomy and/or salpingo-oophorectomy before the index date (January 1st, 2011), or missing/outliers BMI and WC values. Follow-up extended to December 31st, 2021, evaluating the incidences of endometrial, ovarian, and cervical cancer. The hazard ratios (HRs) and 95% confidence intervals (CIs) for each gynecological malignancy according to BMI and WC were calculated using Cox proportional hazard regression. Results: Among the 365,581 participants, 898, 1,268, and 873 cases of endometrial, ovarian, and cervical cancer occurred, respectively. HRs (95% CIs) for endometrial cancer were 1.37 (1.15–1.63), 1.63 (1.38–1.94), and 3.64 (2.81–4.70) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend < 0.001). HRs (95% CIs) for ovarian cancer were 1.16 (1.00–1.33), 1.19 (1.03–1.37), and 1.49 (1.12–1.98) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend = 0.002). No significant association was found between BMI and the risk for cervical cancer (P for trend = 0.266). HRs (95% CIs) for endometrial cancer were 1.35 (1.09–1.66), 1.41 (1.14–1.74), and 1.90 (1.55–2.34) for the 2nd, 3rd, and 4th quartiles of WCs compared to the 1st quartile (P for trend <0.001). Ovarian cancer tended to increase and cervical cancer tended to decrease as WC increased (P for trend = 0.035 for ovarian cancer, P for trend = 0.034 for cervical cancer). Conclusion In Korean women, the risks of endometrial and ovarian cancers increased significantly from the pre-obese level as BMI and WC increased, while cervical cancer risk tended to increase as WC decreased. Management of obesity should be reinforced for the prevention of obesity-related gynecological cancers, considering the increasing incidence of these cancers among Korean women.

Background: This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea. Methods: Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB. Results: Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB. Conclusion Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.

Background: In Korea, the patterns of prevalence of gynecological cancers have shifted due to rising obesity-related cancer cases. We evaluated the associations of body mass index (BMI) and waist circumference (WC) with the risk of gynecological malignancy in Korean women. Methods: Using National Health Insurance Service cohort data, we analyzed 365,581 participants among the 1,999,980 women aged ≥ 19 years who underwent health check-ups at the baseline year 2009–2010, excluding those who died, those with prior cancer diagnoses, underwent hysterectomy and/or salpingo-oophorectomy before the index date (January 1st, 2011), or missing/outliers BMI and WC values. Follow-up extended to December 31st, 2021, evaluating the incidences of endometrial, ovarian, and cervical cancer. The hazard ratios (HRs) and 95% confidence intervals (CIs) for each gynecological malignancy according to BMI and WC were calculated using Cox proportional hazard regression. Results: Among the 365,581 participants, 898, 1,268, and 873 cases of endometrial, ovarian, and cervical cancer occurred, respectively. HRs (95% CIs) for endometrial cancer were 1.37 (1.15–1.63), 1.63 (1.38–1.94), and 3.64 (2.81–4.70) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend < 0.001). HRs (95% CIs) for ovarian cancer were 1.16 (1.00–1.33), 1.19 (1.03–1.37), and 1.49 (1.12–1.98) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend = 0.002). No significant association was found between BMI and the risk for cervical cancer (P for trend = 0.266). HRs (95% CIs) for endometrial cancer were 1.35 (1.09–1.66), 1.41 (1.14–1.74), and 1.90 (1.55–2.34) for the 2nd, 3rd, and 4th quartiles of WCs compared to the 1st quartile (P for trend <0.001). Ovarian cancer tended to increase and cervical cancer tended to decrease as WC increased (P for trend = 0.035 for ovarian cancer, P for trend = 0.034 for cervical cancer). Conclusion In Korean women, the risks of endometrial and ovarian cancers increased significantly from the pre-obese level as BMI and WC increased, while cervical cancer risk tended to increase as WC decreased. Management of obesity should be reinforced for the prevention of obesity-related gynecological cancers, considering the increasing incidence of these cancers among Korean women.

Background: This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea. Methods: Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB. Results: Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB. Conclusion Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.

Background: This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea. Methods: Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB. Results: Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB. Conclusion Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.

Background: In Korea, the patterns of prevalence of gynecological cancers have shifted due to rising obesity-related cancer cases. We evaluated the associations of body mass index (BMI) and waist circumference (WC) with the risk of gynecological malignancy in Korean women. Methods: Using National Health Insurance Service cohort data, we analyzed 365,581 participants among the 1,999,980 women aged ≥ 19 years who underwent health check-ups at the baseline year 2009–2010, excluding those who died, those with prior cancer diagnoses, underwent hysterectomy and/or salpingo-oophorectomy before the index date (January 1st, 2011), or missing/outliers BMI and WC values. Follow-up extended to December 31st, 2021, evaluating the incidences of endometrial, ovarian, and cervical cancer. The hazard ratios (HRs) and 95% confidence intervals (CIs) for each gynecological malignancy according to BMI and WC were calculated using Cox proportional hazard regression. Results: Among the 365,581 participants, 898, 1,268, and 873 cases of endometrial, ovarian, and cervical cancer occurred, respectively. HRs (95% CIs) for endometrial cancer were 1.37 (1.15–1.63), 1.63 (1.38–1.94), and 3.64 (2.81–4.70) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend < 0.001). HRs (95% CIs) for ovarian cancer were 1.16 (1.00–1.33), 1.19 (1.03–1.37), and 1.49 (1.12–1.98) for BMIs of 23.0–24.9, 25.0–29.9, and ≥ 30 kg/m2 compared to BMI of 18.5–22.9 kg/m2 (P for trend = 0.002). No significant association was found between BMI and the risk for cervical cancer (P for trend = 0.266). HRs (95% CIs) for endometrial cancer were 1.35 (1.09–1.66), 1.41 (1.14–1.74), and 1.90 (1.55–2.34) for the 2nd, 3rd, and 4th quartiles of WCs compared to the 1st quartile (P for trend <0.001). Ovarian cancer tended to increase and cervical cancer tended to decrease as WC increased (P for trend = 0.035 for ovarian cancer, P for trend = 0.034 for cervical cancer). Conclusion In Korean women, the risks of endometrial and ovarian cancers increased significantly from the pre-obese level as BMI and WC increased, while cervical cancer risk tended to increase as WC decreased. Management of obesity should be reinforced for the prevention of obesity-related gynecological cancers, considering the increasing incidence of these cancers among Korean women.