Coronary artery calcification (CAC) is highly prevalent in patients with chronic kidney disease (CKD) and is associated with major adverse cardiovascular events and metabolic disturbances. The triglyceride-glucose index (TyGI), a novel surrogate marker of metabolic syndrome and insulin resistance, is associated with CAC in the general population and in patients with diabetes. This study investigated the association between the TyGI and CAC progression in patients with CKD, which is unknown. Methods: A total of 1,154 patients with CKD (grades 1–5; age, 52.8 ± 11.9 years; male, 688 [59.6%]) were enrolled from the KNOWCKD (KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease). The TyGI was calculated as follows: ln (fasting triglycerides × fasting glucose/2). Patients were classified into tertiles (low, intermediate, high) based on the TyGI. The primary outcome was annualized percentage change in CAC score [(percent change in CAC score + 1)12/follow-up months – 1] of ≥15%, defined as CAC progression. Results: During the 4-year follow-up, the percentage of patients with CAC progression increased across TyGI groups (28.6%, 37.5%, and 46.2% in low, intermediate, and high groups, respectively; p < 0.001). A high TyGI was associated with an increased risk of CAC progression (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.14–3.88; p = 0.02) compared to the low group. Moreover, a 1-point increase in the TyGI was related to increased risk of CAC progression (OR, 1.55; 95% CI, 1.06–1.76; p = 0.02) after adjustment. Conclusion: A high TyGI may be a useful predictor of CAC progression in CKD.

Background: The optimal level of glycosylated hemoglobin (HbA1c) to prevent adverse clinical outcomes is unknown in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). Methods: We analyzed 707 patients with CKD G1-G5 without kidney replacement therapy and T2DM from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD), a nationwide prospective cohort study. The main predictor was time-varying HbA1c level at each visit. The primary outcome was a composite of development of major adverse cardiovascular events (MACEs) or all-cause mortality. Secondary outcomes included the individual endpoint of MACEs, all-cause mortality, and CKD progression. CKD progression was defined as a ≥50% decline in the estimated glomerular filtration rate from baseline or the onset of end-stage kidney disease. Results: During a median follow-up of 4.8 years, the primary outcome occurred in 129 (18.2%) patients. In time-varying Cox model, the adjusted hazard ratios (aHRs) for the primary outcome were 1.59 (95% confidence interval [CI], 1.01 to 2.49) and 1.99 (95% CI, 1.24 to 3.19) for HbA1c levels of 7.0%–7.9% and ≥8.0%, respectively, compared with <7.0%. Additional analysis of baseline HbA1c levels yielded a similar graded association. In secondary outcome analyses, the aHRs for the corresponding HbA1c categories were 2.17 (95% CI, 1.20 to 3.95) and 2.26 (95% CI, 1.17 to 4.37) for MACE, and 1.36 (95% CI, 0.68 to 2.72) and 2.08 (95% CI, 1.06 to 4.05) for all-cause mortality. However, the risk of CKD progression did not differ between the three groups. Conclusion This study showed that higher HbA1c levels were associated with an increased risk of MACE and mortality in patients with CKD and T2DM.

The new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations without a race coefficient have gained recognition across the United States. We aimed to test whether these new equations performed well in Korean patients with chronic kidney disease (CKD). Methods: This study included 2,149 patients with CKD G1–G5 without kidney replacement therapy from the Korean Cohort Study for Outcome in Patients with CKD (KNOW-CKD). The estimated glomerular filtration rate (eGFR) was calculated using the new CKD-EPI equations with serum creatinine and cystatin C. The primary outcome was 5-year risk of kidney failure with replacement therapy (KFRT). Results: When we adopted the new creatinine equation [eGFRcr (NEW)], 81 patients (23.1%) with CKD G3a based on the current creatinine equation (eGFRcr) were reclassified as CKD G2. Accordingly, the number of patients with eGFR of <60 mL/min/1.73 m2 decreased from 1,393 (64.8%) to 1,312 (61.1%). The time-dependent area under the receiver operating characteristic curve for 5-year KFRT risk was comparable between the eGFRcr (NEW) (0.941; 95% confidence interval [CI], 0.922–0.960) and eGFRcr (0.941; 95% CI, 0.922–0.961). The eGFRcr (NEW) showed slightly better discrimination and reclassification than the eGFRcr. However, the new creatinine and cystatin C equation [eGFRcr-cys (NEW)] performed similarly to the current creatinine and cystatin C equation. Furthermore, eGFRcr-cys (NEW) did not show better performance for KFRT risk than eGFRcr (NEW). Conclusion: Both the current and the new CKD-EPI equations showed excellent predictive performance for 5-year KFRT risk in Korean patients with CKD. These new equations need to be further tested for other clinical outcomes in Koreans.

Purpose: Alpha-fetoprotein (AFP) is a prognostic marker for hepatocellular carcinoma (HCC). We investigated the prognostic value of AFP levels in patients who achieved complete response (CR) to transarterial chemoembolization (TACE) for HCC. Materials and Methods: Between 2005 and 2018, 890 patients with HCC who achieved a CR to TACE were recruited. An AFP responder was defined as a patient who showed elevated levels of AFP (>10 ng/mL) during TACE, but showed normalization or a >50% reduction in AFP levels after achieving a CR. Results: Among the recruited patients, 569 (63.9%) with naïve HCC and 321 (36.1%) with recurrent HCC after complete resection were treated. Before TACE, 305 (34.3%) patients had multiple tumors, 219 (24.6%) had a maximal tumor size >3 cm, and 22 (2.5%) had portal vein tumor thrombosis. The median AFP level after achieving a CR was 6.36 ng/mL. After a CR, 473 (53.1%) patients experienced recurrence, and 417 (46.9%) died [median progression-free survival (PFS) and overall survival (OS) of 16.3 and 62.8 months, respectively]. High AFP levels at CR (>20 ng/mL) were independently associated with a shorter PFS [hazard ratio (HR)=1.403] and OS (HR=1.284), together with tumor multiplicity at TACE (HR=1.518 and 1.666, respectively). AFP non-responders at CR (76.2%, n=359 of 471) showed a shorter PFS (median 10.5 months vs. 15.5 months, HR=1.375) and OS (median 41.4 months vs. 61.8 months, HR=1.424) than AFP responders (all p=0.001). Conclusion High AFP levels and AFP non-responders were independently associated with poor outcomes after TACE. AFP holds clinical implications for detailed risk stratification upon achieving a CR after TACE.

Purpose: In young patients with varicocele, preservation of the internal spermatic artery may be advantageous for catch-up growth, but it may also increase the likelihood of treatment failure. Intraoperative venography reduces the likelihood that unsealed veins will remain after varicocelectomy. We analyzed the characteristics of remnant veins visualized through intraoperative venography to investigate the cause of surgical failure in artery-sparing varicocelectomy (ASV). Materials and Methods: We retrospectively analyzed clinical characteristics and outcomes of patients aged 18 years or younger who underwent varicocelectomy with intraoperative venography from January 2005 to December 2017. During varicocelectomy, intraoperative venography was performed to distinguish veins from other structures. Any unsealed veins that were discovered were ligated and classified using the Bähren system. Results: One hundred and sixty-two patients underwent intraoperative venography: 153 cases (94.4%) were for primary varicocelectomy, and 9 cases (5.6%) were for repeat varicocelectomy. Open varicocelectomy was performed in 105 cases (64.8%), and laparoscopic varicocelectomy was performed in 57 cases (35.2%). Venography revealed remnant veins after the first ligation in 51 cases (31.2%), 46 (90.2%) and 5 (9.8%) of which were Bähren types 3 and 4, respectively. Five patients (3.1%) experienced varicocele recurrence, classified as persistence in 1 patient (0.6%) and relapse in 4 patients (2.5%). Conclusion Remnant collateral veins of the internal spermatic vein (ISV) (Bähren type 3) are the most common cause of failure in ASV. In a few patients, an external spermatic vein merges with the ISV at a higher level (Bähren type 4) and is unidentifiable without venography.

Purpose: In young patients with varicocele, preservation of the internal spermatic artery may be advantageous for catch-up growth, but it may also increase the likelihood of treatment failure. Intraoperative venography reduces the likelihood that unsealed veins will remain after varicocelectomy. We analyzed the characteristics of remnant veins visualized through intraoperative venography to investigate the cause of surgical failure in artery-sparing varicocelectomy (ASV). Materials and Methods: We retrospectively analyzed clinical characteristics and outcomes of patients aged 18 years or younger who underwent varicocelectomy with intraoperative venography from January 2005 to December 2017. During varicocelectomy, intraoperative venography was performed to distinguish veins from other structures. Any unsealed veins that were discovered were ligated and classified using the Bähren system. Results: One hundred and sixty-two patients underwent intraoperative venography: 153 cases (94.4%) were for primary varicocelectomy, and 9 cases (5.6%) were for repeat varicocelectomy. Open varicocelectomy was performed in 105 cases (64.8%), and laparoscopic varicocelectomy was performed in 57 cases (35.2%). Venography revealed remnant veins after the first ligation in 51 cases (31.2%), 46 (90.2%) and 5 (9.8%) of which were Bähren types 3 and 4, respectively. Five patients (3.1%) experienced varicocele recurrence, classified as persistence in 1 patient (0.6%) and relapse in 4 patients (2.5%). Conclusion Remnant collateral veins of the internal spermatic vein (ISV) (Bähren type 3) are the most common cause of failure in ASV. In a few patients, an external spermatic vein merges with the ISV at a higher level (Bähren type 4) and is unidentifiable without venography.

Background: Since September 2015, the initiation of antiviral therapy (AVT) for patients with chronic hepatitis B (CHB)-related cirrhosis has been reimbursed according to the revised Korean Association for the Study of Liver (KASL) guideline, if the patient had hepatitis B virus DNA level ≥ 2,000 IU/L, regardless of aminotransferase or alanine aminotransferase levels. This study investigated whether the KASL guideline implementation reduced the risk of CHB-related hepatocellular carcinoma (HCC) in patients with cirrhosis in South Korea. Methods: A total of 429 patients with CHB-related cirrhosis who initiated AVT between 2014 and 2016 were recruited. The risk of HCC development was compared between patients who initiated AVT before and after September 2015 (pre-guideline [n = 196, 45.7%] vs. postguideline implementation [n = 233, 54.3%]). Results: Univariate analysis showed that AVT initiation before guideline implementation, older age, male gender, and diabetes significantly predicted increased risk of HCC development (all P < 0.05). Subsequent multivariate analysis showed that AVT initiation before guideline implementation (HR = 1.941), older age (HR = 5.762), male gender (HR = 2.555), and diabetes (HR = 1.568) independently predicted increased risk of HCC development (all P < 0.05). Additionally, multivariate analysis showed that AVT initiation before guideline implementation (HR = 2.309), male gender (HR = 3.058), and lower platelet count (HR = 0.989) independently predicted mortality (P < 0.05). The cumulative incidences of HCC and mortality were significantly higher in patients who initiated AVT before guideline implementation than in those who initiated AVT after guideline implementation (all P < 0.05, log-rank test). Conclusion The prognosis of patients with CHB-related cirrhosis who initiated AVT improved after guideline implementation according to the revised KASL guideline.

Background: Since September 2015, the initiation of antiviral therapy (AVT) for patients with chronic hepatitis B (CHB)-related cirrhosis has been reimbursed according to the revised Korean Association for the Study of Liver (KASL) guideline, if the patient had hepatitis B virus DNA level ≥ 2,000 IU/L, regardless of aminotransferase or alanine aminotransferase levels. This study investigated whether the KASL guideline implementation reduced the risk of CHB-related hepatocellular carcinoma (HCC) in patients with cirrhosis in South Korea. Methods: A total of 429 patients with CHB-related cirrhosis who initiated AVT between 2014 and 2016 were recruited. The risk of HCC development was compared between patients who initiated AVT before and after September 2015 (pre-guideline [n = 196, 45.7%] vs. postguideline implementation [n = 233, 54.3%]). Results: Univariate analysis showed that AVT initiation before guideline implementation, older age, male gender, and diabetes significantly predicted increased risk of HCC development (all P < 0.05). Subsequent multivariate analysis showed that AVT initiation before guideline implementation (HR = 1.941), older age (HR = 5.762), male gender (HR = 2.555), and diabetes (HR = 1.568) independently predicted increased risk of HCC development (all P < 0.05). Additionally, multivariate analysis showed that AVT initiation before guideline implementation (HR = 2.309), male gender (HR = 3.058), and lower platelet count (HR = 0.989) independently predicted mortality (P < 0.05). The cumulative incidences of HCC and mortality were significantly higher in patients who initiated AVT before guideline implementation than in those who initiated AVT after guideline implementation (all P < 0.05, log-rank test). Conclusion The prognosis of patients with CHB-related cirrhosis who initiated AVT improved after guideline implementation according to the revised KASL guideline.

Background: Higher statin intensity is associated with a lower risk of mortality in patients with cardiovascular disease. However, little is known about the relationship between statin intensity and chronic kidney disease (CKD) progression. Methods: We studied whether statin intensity affects kidney function decline in 1,073 patients from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease. The participants were classified based on statin intensity as low, moderate, and high. The study endpoint was CKD progression (composite of doubling of serum creatinine, ≥ 50% decrease in estimated glomerular filtration rate [eGFR] from baseline, or end-stage renal disease). Results: The mean age was 56.0 ± 11.4 years, and 665 (62.0%) participants were male. The mean eGFR was 51.7 ± 26.7 mL/min/1.73 m2; there were no differences in baseline eGFR among statin intensity groups. During the median follow-up of 39.9 (25.4-61.6) months, 255 (23.8%) patients reached the study endpoint. In multivariable Cox model after adjustment of confounders, the hazard ratios (95% confidence interval) for adverse kidney outcome were 0.97 (0.72-1.30) and 1.15 (0.60-2.20) in moderate and high statin intensity groups, respectively, compared with the low intensity group. In addition, no significant association was observed in subgroups stratified by age, sex, eGFR, and atherosclerotic cardiovascular disease risk scores. Conclusion We did not observe any significant association between intensity of statin therapy and progression of CKD. Long-term kidney outcomes may not be affected by statin intensity.