Min-Uk Cha

Body mass index is inversely associated with mortality in patients with acute kidney injury undergoing continuous renal replacement therapy

Background Many epidemiologic studies have reported on the controversial concept of the obesity paradox. The presence of acute kidney injury (AKI) can accelerate energy-consuming processes, particularly in patients requiring continuous renal replacement therapy (CRRT). Thus, we aimed to investigate whether obesity can provide a survival benefit in this highly catabolic condition. Methods We conducted an observational study in 212 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. The study end point was defined as death that occurred within 30 days after the initiation of CRRT. Results Patients were categorized into three groups according to tertiles of body mass index (BMI). During ≥30 days after the initiation of CRRT, 39 patients (57.4%) in the highest tertile died, as compared with 58 patients (78.4%) in the lowest tertile (P = 0.02). In a multivariable analysis adjusted for cofounding factors, the highest tertile of BMI was significantly associated with a decreased risk of death (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.37–0.87; P = 0.01). This significant association remained unaltered for 60-day (HR, 0.64; 95% CI, 0.43–0.94; P = 0.03) and 90-day mortality (HR, 0.66; 95% CI, 0.44–0.97; P = 0.03). Conclusion This study showed that a higher BMI confer a survival benefit over a lower BMI in AKI patients undergoing CRRT.

Effects of Coffee Intake on Incident Chronic Kidney Disease: Community-Based Prospective Cohort Study

BACKGROUND Drinking coffee can raise public health problems, but the association between coffee and kidney disease is unknown. We studied whether coffee intake can affect the development of chronic kidney disease in the general population. METHODS We analyzed 8717 subjects with normal renal function recruited from the Korean Genome and Epidemiology Study (KoGES) cohort. Based on a food frequency questionnaire, coffee consumption was categorized into 5 groups: 0 per week, <1 cup per week, 1-6 cups per week, 1 cup per day, and ≥2 cups per day. The primary outcome was incident chronic kidney disease, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. RESULTS The mean age (standard deviation) of study subjects was 52.0 (8.8) years, and 47.8% were male. Among the subjects, 52.8% were daily coffee consumers. During a mean follow-up of 11.3 (range, 5.9-11.5) years, 9.5% of participants developed chronic kidney disease. The incident chronic kidney disease occurred less in daily coffee consumers. Unadjusted hazard ratios (HRs) was significantly lower in daily coffee consumers. In multivariable Cox model even after adjustment of blood pressure, hypertension, cardiovascular disease, diabetes, and amount of daily intake for caffeine-containing foods such as tea and chocolate, coffee consumers with 1 cup per day (HR, 0.76; 95% confidence interval, 0.63-0.92) and ≥2 cups per day (HR, 0.80; 95% confidence interval, 0.65-0.98) were associated with a lower risk of chronic kidney disease development than nondrinkers. Time-averaged and time-varying Cox models yielded similar results. The rates of decline in glomerular filtration were lower in daily coffee consumers. CONCLUSIONS Our findings suggest that daily coffee intake is associated with decreased risk of the development of chronic kidney disease.

Microscopic hematuria is a risk factor of incident chronic kidney disease in the Korean general population: a community-based prospective cohort study

Background Although asymptomatic microscopic hematuria (MH) is a common finding in clinical practice, its long-term outcome remains unknown. Aim This study evaluated the clinical implication of MH in the general population using a large-scale long-term longitudinal cohort database. Methods This study included 8719 participants from the Korean Genome and Epidemiology Study between 2001 and 2014. MH was defined as ≥5 red blood cells per high-power field in random urinalysis without evidence of pyuria. The primary study outcome measure was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate <60 ml min-1⋅1.73⋅m-2. Results During a median follow-up of 11.7 years, CKD occurred in 677 (7.8%) subjects. In Cox regression after adjustment for multiple confounders, subjects with MH had a significantly higher risk of incident CKD than those without [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.12-1.87; P = 0.005]. Isolated MH without proteinuria was also a risk factor of incident CKD (HR 1.37, 95% CI 1.04-1.79; P = 0.023) and the risk was further increased in MH with concomitant proteinuria (HR 5.41, 95% CI 2.54-11.49; P < 0.001). In propensity score matching analysis after excluding subjects with proteinuria, multi-variable stratified Cox regression analysis revealed that subjects with isolated MH had a significantly higher risk of incident CKD than those without (HR 1.83, 95% CI 1.14-2.94; P = 0.012). Conclusion The presence of MH is associated with an increased risk of incident CKD in the general population. Therefore, attentive follow-up is warranted in persons with MH for early detection of CKD.

Neck circumference predicts renal function decline in overweight women: A community-based prospective cohort study

AbstractChronic kidney disease (CKD) is characterized by increased risks of morbidity and mortality. Upper-body subcutaneous fat, which is commonly estimated from the neck circumference (NC), was revealed to be the main reservoir of circulating nonesterified fatty acids in overweight patients. Despite a close association between NC and metabolic complications, the relationship of NC with renal function has not been fully investigated. In this study, the impact of NC on the development of incident CKD was elucidated.The data were retrieved from the Korean Genome and Epidemiology Study cohort. The subjects were followed at 2-year intervals from 2003 to 2011. Overweight was defined as a body mass index of ≥23 kg/m2. A total of 4298 cohort subjects were screened. After exclusion, 2268 overweight subjects were included for the final analysis. The primary end point was incident CKD, which was defined as a composite of estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or the development of proteinuria.The mean patient age was 36.3 ± 3.0 years, and 1285 (56.7%) were men. They were divided into 2 groups according to the median NC in male and female subjects, separately. In both sexes, hypertension (men, P < 0.001; women, P = 0.009) and diabetes (men, P = 0.002; women, P < 0.001) were significantly more prevalent in the big NC group than in the small NC group. In contrast, eGFR was significantly lower only in male subjects of the big NC group (P < 0.001), whereas it was comparable between the small and big NC groups (P = 0.167). In multivariate Cox proportional hazards regression analysis, NC values were independently associated with incident CKD development in female subjects after adjusting for multiple confounding factors (per 1 cm increase, hazard ratio [95% confidence interval] = 1.159 [1.024–1.310], P = 0.019) but not in male subjects.NC is independently associated with the development of CKD in overweight female subjects, suggesting that it could be a practical risk factor for CKD.

PS 11-15 HIGH ANKLE-BRACHIAL INDEX (ABI) REFLECTS INCREASED TRADITIONAL CARDIOVASCULAR RISK FACTORS, BUT LOW ABI IS ASSOCIATED WITH VASCULAR CALCIFICATION IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Objective: Ankle-brachial index (ABI) is a method for predicting vascular dysfunction. Previous reports demonstrated the proportion of high (≥1.3) as well as low (⩽0.9) ABI increases as decreasing estimated glomerular filtration rate (eGFR) and abnormal ABI is associated with cardiovascular (CV) risks in CKD population. The aim of this study was to investigate the association between ABI and CV risks in patients with CKD. Design and Method: Data was recruited from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD), a prospective cohort study, enrolls subjects with CKD (predialysis). The patients were divided into three groups according to ABI; low (⩽0.9), high (≥1.3), or normal ABI group. Multiple logistic regression analysis was used to identify the association between abnormal ABI and CV risks. Results: A total of 1,818 patients were enrolled. The mean age was 53.5 ± 12.3 years. Abnormal ABI group showed significantly older age (low vs normal vs high: 58.5 ± 11.9 vs 52.7 ± 12.3 vs 59.5 ± 9.6 years, P < 0.001), more male (71.4 vs 59.7 vs 77.4%, P < 0.001), prevalent diabetes (53.6 vs 29.0 vs 48.8%, P < 0.001), higher left ventricular mass index (LVMI) (104 ± 30 vs 93 ± 25 vs 106 ± 25 g/m3, P < 0.001), and log coronary calcium score (logCCS) (4.8 ± 2.0 vs 3.4 ± 1.6 vs 4.3 ± 1.8, P < 0.001), while eGFR was significantly lower in abnormal ABI group (41.8 ± 24.1 vs 51.2 ± 30.3 vs 41.1 ± 26.3 ml/min/1.73m2, P < 0.001). In multiple logistic regression, older (odds ratio [OR], 1.060; 95% confidence interval [CI], 1.029–1.091, P < 0.001), male (OR, 4.731; 95% CI, 2.169–10.317, P < 0.001), smoking (OR, 0.502; 95% CI, 0.267–0.945, P = 0.033), and LVMI (OR, 1.016; 95% CI, 1.005–1.028, P = 0.005) were associated with higher ABI group, while logCCS (OR, 1.313; 95% CI, 1.082–1.592, P = 0.006) was independently associated with low ABI group. Conclusions: Abnormal ABI is associated with CV risks in patients with CKD. However, present study suggests that high and low ABI might have substantial difference from pathophysiological mechanisms in CKD patients.

Low Dentin Matrix Protein 1 Is Associated With Incident Cardiovascular Events in Peritoneal Dialysis Patients

Recent reports demonstrated that dentin matrix protein 1 (DMP1) acts as an inhibitor of vascular calcification and might be a potential biomarker for chronic kidney disease‐mineral and bone disorder; however, no clinical investigations regarding DMP1 have been performed in dialysis patients. We investigated the prognostic value of DMP1 on cardiovascular outcomes in prevalent peritoneal dialysis patients. We recruited 223 prevalent peritoneal dialysis patients and divided them into high and low DMP1 groups according to log‐transformed plasma DMP1 levels. Lateral lumbar spine radiographs were used for measurement of vascular calcification. Major cardiovascular events were compared between the two groups. A Cox proportional hazards analysis determined DMP1 was independently associated with cardiovascular outcomes. In vitro mouse osteocytes were cultured in media containing indoxyl sulfate (IS), and the expressions of DMP1 were examined. The mean age was 52.1 ± 11.8 years, and 116 (52.0%) patients were male. The median value of log DMP1 was 0.91 (0.32–2.81 ng/mL). The multiple logistic regression analysis indicated that DMP1 levels were independently associated with the presence of vascular calcification after adjustment for multiple confounding factors (odds ratio = 0.719; 95% confidence interval [CI] 0.522–0.989; p = 0.043). During a mean follow‐up duration of 34.6 months, incident cardiovascular events were observed in 41 (18.4%) patients. A Kaplan‐Meier plot showed that the low DMP1 group had a significantly higher rate of incident cardiovascular events compared with the high DMP1 group (log‐rank test, p = 0.026). In addition, multiple Cox analysis showed that low DMP1 was significantly associated with incident cardiovascular events (log 1 increase: hazard ratio = 0.855; 95% CI 0.743–0.984; p = 0.029) after adjustment for multiple confounding factors. In IS‐stimulated osteocytes, mRNA and protein expression levels of DMP1 were significantly decreased compared with control osteocytes. We showed that low DMP1 levels were significantly associated with presence of vascular calcification and were independently associated with the incident cardiovascular events in prevalent peritoneal dialysis patients. DMP1 might be a potential factor contributing to cardiovascular complications in dialysis patients.