Blood pressure prior to percutaneous coronary intervention is associated with the risk of end-stage renal disease: a nationwide population based-cohort study

Background

Hypertension is the most important modifiable risk factor for mortality and morbidity in chronic kidney disease and coronary artery syndrome. The effect of hypertension prior to percutaneous coronary intervention (PCI) on the development of end-stage renal disease (ESRD) is unknown.

Methods

We used nationally representative data from the Korean National Health Insurance System-140,164 subjects were enrolled during 2010-2015; they were free of ESRD at enrolment, underwent PCI, and were followed up until 2017. Blood pressure (BP) was measured within at least 2 years prior to PCI. The primary outcome was the development of ESRD.

Results

During a median follow-up of 5.4 years, 2,082 participants (1.5%) developed ESRD. The highest systolic BP group (>160 mmHg) showed a higher hazard ratio (3.69; 95% confidence interval, 2.61-5.23) than the reference group (110-119 mmHg). Similar results were observed in the highest diastolic BP group (>120 mmHg), which showed a higher hazard ratio than the reference group (70-79 mmHg). However, ESRD risk showed a J-shaped relationship with baseline systolic and diastolic BP at 113 and 74 mmHg in diabetes mellitus subgroup, respectively, after adjustment for potential confounders.

Conclusion

Our study showed that a high systolic or diastolic BP prior to PCI was independently associated with an increased incidence of ESRD.

Retroperitoneal emphysema caused by a renal abscess: a case report

We report a case of retroperitoneal emphysema caused by a renal abscess. A 45-year-old man with underlying type 2 diabetes mellitus visited the emergency department with right flank pain and a fever. On physical examination, right costovertebral tenderness in the ipsilateral flank was noted. Leukocytosis and high inflammatory marker levels were observed. Urinalysis showed pyuria and glucosuria. Urine culture was positive for Streptococcus agalactiae. A computed tomography scan of the abdomen showed a focal, lowattenuation lesion in the right kidney with a 3 cm, exophytic, high-attenuation lesion in the right kidney upper pole and gas-containing fluid collection within the retroperitoneal space. The diagnosis was retroperitoneal emphysema caused by a renal abscess. As the vital signs were stable and the patient refused puncture, we decided on a course of antibiotics alone with follow-up without percutaneous drainage or surgery. The patient improved without any complications. This is a rare case of a renal abscess penetrating the renal fascia and progressing to a posterior paranephric emphysema. The patient was treated with antibiotics alone and cured successfully. Early diagnosis and proper treatment are needed, and percutaneous drainage or urgent surgery would be beneficial for such cases depending on the patient's condition.

MO104RISK OF END-STAGE RENAL DISEASE: PREDICTION USING CUMULATIVE NUMBER OF HYPERTENSION DIAGNOSES

Background and Aims

Hypertension is the leading risk factor for end-stage renal disease (ESRD). However, the association between repeated measurements of high blood pressure and ESRD is not well-established. This study investigated whether the cumulative number of diagnoses of hypertension is a substantial risk factor for ESRD.

Method

The incidence of ESRD among 2,144,801 participants, identified from the Korean National Health Insurance Service database, who did not have a history of antihypertensive therapy and had documented blood pressure assessments for 4 consecutive years was determined retrospectively. Data were extracted from the database where events of hypertension were defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg.

Results

Over a median follow-up of 7.2 years, ESRD was identified in 1758 of the 2,144,801 participants. In a multivariable Cox model adjusted for age, sex, smoking, alcohol consumption, exercise, and history of diabetes and chronic kidney disease, a positive dose-dependent relationship between the cumulative number of diagnoses of hypertension and ESRD was found (adjusted hazard ratio for ESRD, 2.70 in 4 cumulative number of diagnoses of hypertension compared to no history of hypertension). This association was maintained for the cumulative number of diagnoses of both systolic and diastolic hypertension.

Conclusion

The cumulative number of diagnoses of systolic or diastolic hypertension increases the risk of ESRD. Therefore, preventive treatment to avoid repetitive events of systolic or diastolic hypertension may be important to lower the risk of ESRD in this clinical population.

Effect of urinary angiotensinogen and high-salt diet on blood pressure in patients with chronic kidney disease: results from the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease (KNOW-CKD)

BACKGROUND/AIMS

This study aimed to investigate whether urinary angiotensinogen (UAGT) excretion was associated with elevated blood pressure in patients with chronic kidney disease (CKD) and to evaluate the relationship among blood pressure, intra-renal renin-angiotensin system (RAS) activity, and dietary sodium in patients with CKD.

METHODS

Participants from the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease (KNOW-CKD) were included. Of the total cohort of 2,238 individuals with CKD, we included 1,955 participants who underwent complete 24-hour urinary sodium (24-hour UNa) analysis. They were categorized into three groups according to three tertiles of their 24-hour UNa, reflecting daily salt intake. To measure intra-renal RAS activity, the UAGT excretion was assayed with an enzyme-linked immunosorbent assay.

RESULTS

Elevated 24-hour UNa levels, logarithm of UAGT-to-creatinine ratio (UAGT/Cr), increased waist-to-hip ratio, and decreased estimated glomerular filtration rate were the risk factors for increased systolic blood pressure. Systolic blood pressure showed a positive correlation with 24-hour UNa levels and logarithm of UAGT/Cr.

CONCLUSION

UAGT and urinary sodium excretion are independent determinants of systolic blood pressure in patients with CKD. These findings suggest that increased systolic blood pressure in CKD patients is associated with both increased dietary sodium levels and intra-renal RAS activity. The risk of elevated systolic blood pressure in the 3rd tertile of both the UAGT/Cr and 24-hour UNa groups was about 2.3 times higher than that in the reference group.

Trends in the incidence and prevalence of end-stage renal disease with hemodialysis in entire Korean population: A nationwide population-based study

Data on the overall epidemiology and temporal trends of end-stage renal disease (ESRD) requiring hemodialysis in Korea are scarce. We aimed to estimate the prevalence and incidence of ESRD requiring hemodialysis in Korea between 2002 and 2017.Using the National Health Insurance Service database, we analyzed data from the entire Korean population between 2002 and 2017. Hemodialysis patients were identified using rare incurable disease codes (V001) or prescription of medical fee codes of hemodialysis (O7020 and O7021). We only included patients who had been maintained on hemodialysis for more than 90 days from the date of dialysis initiation, to exclude patients who required short-term dialysis for acute kidney injury, conversion to peritoneal dialysis, or kidney transplantation.During the 16-year follow-up, the number of hemodialysis patients in Korea has steadily increased from 11,215 in 2002 to 67,486 in 2017. The mean age of these patients has gradually increased from 55.57 ± 13.31 years in 2002 to 62.13 ± 13.23 years in 2017. In 2017, the crude prevalence rate of hemodialysis was 1303.4 per million population. Overall, the number of men tended to be somewhat higher than that of women, and the proportion of men increased slightly from 55.56% in 2002 to 58.45% in 2017. The proportion of diabetic patients increased rapidly from 23.84% to 47.84%, and the percentage of dyslipidemic patients rose from 18.9% to 86.7%. The number of incident hemodialysis patients increased significantly from 4406 in 2003 to 12,134 in 2014, and then decreased to 8090 in 2017. In the incident cases of hemodialysis, the observed increase in the proportion of male patients and in diabetes and dyslipidemia were similar to that of prevalent patients. The more recent era of hemodialysis initiation, the better 5-year survival rates were observed.The prevalence and incidence of hemodialysis in Korea gradually increased between 2002 and 2017. The proportion of men, and patients with diabetes and dyslipidemia requiring hemodialysis also increased continuously. The survival rate of hemodialysis patients was gradually improving. These findings may serve as a reference for future epidemiological studies on hemodialysis in Korea.

Chronic Kidney Disease Risk of Isolated Systolic or Diastolic Hypertension in Young Adults: A Nationwide Sample Based-Cohort Study

Background

Hypertension among young adults is common. However, the effect of isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), or systolic and diastolic hypertension (SDH) among young adults on chronic kidney disease (CKD) development is unknown.

Methods and Results

From a nationwide health screening database, we included 3 030 884 participants aged 20 to 39 years who were not taking antihypertensives at baseline examination in 2009 to 2010. Participants were categorized as having normal blood pressure (BP), elevated BP, stage 1 IDH, stage 1 ISH, stage 1 SDH, stage 2 IDH, stage 2 ISH, and stage 2 SDH. The primary outcome was incident CKD. A total of 5853 (0.19%) CKD events occurred. With normal BP as the reference, multivariable‐adjusted hazard ratios (HRs) (95% CIs) for CKD were 1.14 (95% CI, 1.04–1.26), elevated BP; 1.19 (95% CI, 1.10–1.28), stage 1 IDH; 1.24 (95% CI, 1.08–1.42), stage 1 ISH; 1.39 (95% CI, 1.28–1.51), stage 1 SDH; 1.88 (95% CI, 1.63–2.16), stage 2 IDH; 1.84 (95% CI, 1.54–2.19), stage 2 ISH; 2.70 (95% CI, 2.44–2.98), stage 2 SDH. The HRs for CKD were attenuated in the patients who were antihypertensive and began medication within 1 year of medical checkup than in those without antihypertensives.

Conclusions

Among Korean young adults, those with elevated BP, stage 1 IDH, stage 1 ISH, stage 1 SDH, stage 2 IDH, stage 2 ISH, and stage 2 SDH were associated with a higher CKD risk than those with normal BP. The CKD risk in ISH and IDH groups was similar but lower than that in the SDH group. Antihypertensives attenuated the risk of CKD in young adults with hypertension.

Kidney-accumulating olmesartan-loaded nanomicelles ameliorate the organ damage in a murine model of Alport syndrome

ACE inhibitors or angiotensin II receptor blockers (ACEi/ARBs) have been a cornerstone of the management in kidney disease, but their use is often limited by undesired systemic effects, such as symptomatic hypotension. To minimize the extra-renal effects of ACEi/ARBs, we formulated hydrophobically modified glycol chitosan (HGC) nanomicelles releasing olmesartan (HGC-Olm) that specifically accumulated in the kidney, and investigated whether kidney-specific delivery of olmesartan by HGC nanomicelles could ameliorate organ damage in Col4a3^-/- mouse, a murine model of progressive chronic kidney disease mimicking human Alport syndrome. Ex vivo tracing demonstrated that intravenously injected HGC-Olm nanomicelles were specifically delivered to the kidney, with sustained release of olmesartan for more than 48 h. Contrary to the conventional delivery of olmesartan via oral route, injection of HGC-Olm nanomicelles did not alter blood pressure in Col4a3^-/- mice. Immunohistochemistry revealed that HGC nanomicelles were diffusely distributed from the cortex and glomeruli to the outer medulla, sparing the inner medulla. Phenotypic analysis showed that the attenuation of kidney fibrosis in the kidney of Col4a3^-/- mice by HGC-Olm nanomicelles was comparable to that noted with conventionally delivered olmesartan. Therefore, our results suggest that HGC-Olm nanomicelles could be a safe and effective alternative drug delivery system for kidney diseases.

Obesity, Abdominal Obesity and Chronic Kidney Disease in Young Adults: A Nationwide Population-Based Cohort Study

Obesity has become a pandemic. It is one of the strongest risk-factors of new-onset chronic kidney disease (CKD). However, the effects of obesity and abdominal obesity on the risk of developing CKD in young adults has not been elucidated. From a nationwide health screening database, we included 3,030,884 young adults aged 20–39 years without CKD during a baseline examination in 2009–2010, who could follow up during 2013–2016. Patients were stratified into five levels based on their baseline body mass index (BMI) and six levels based on their waist circumference (WC; 5-cm increments). The primary outcome was the development of CKD. During the follow up, until 2016, 5853 (0.19%) participants developed CKD. Both BMI and WC showed a U-shaped relationship with CKD risk, identifying the cut-off values as a BMI of 21 and WC of 72 cm in young adults. The obesity group (odd ratio [OR] = 1.320, 95% confidence interval [CI]: 1.247–1.397) and abdominal obesity group (male WC ≥ 90, female WC ≥ 85) (OR = 1.208, 95%CI: 1.332–1.290) showed a higher CKD risk than the non-obesity or non-abdominal obesity groups after adjusting for covariates. In the CKD risk by obesity composite, the obesity displayed by the abdominal obesity group showed the highest CKD risk (OR = 1.502, 95%CI: 1.190–1.895), especially in those under 30 years old. During subgroup analysis, the diabetes mellitus (DM) group with obesity or abdominal obesity paradoxically showed a lower CKD risk compared with the non-obesity or non-abdominal obesity group. Obesity and abdominal obesity are associated with increased risk of developing CKD in young adults but a decreased risk in young adults with diabetes.

Parental educational status independently predicts the risk of prevalent hypertension in young adults

Identification of individuals at risk of hypertension development based on socio-economic status have been inconclusive, due to variable definitions of low socio-economic status. We investigated whether educational status of individuals or their parents predicts prevalent hypertension in young adult population, by analyzing data of more than 37,000 non-institutionalized subjects from Korea National Health and Nutrition Examination Survey 2008 to 2017. Although low educational status of individual subjects was robustly associated with elevation of systolic blood pressure and increased prevalence of hypertension in general population, its impact on prevalent hypertension differed across age subgroups, and was remarkably attenuated in young adults. Parental educational status was significantly associated with prevalent hypertension in young adults, but not or only marginally in elderly population. Low parental educational status was also associated with high sodium intake in young adults, irrespective of subject’s own educational status. These collectively indicate that parental educational status, rather than individual’s own educational status, better and independently predicts prevalent hypertension in young adults, and that young adults with low parental educational status are prone to intake more sodium, possibly contributing to the increased risk of hypertension development. We expect that our findings could help define young individuals at risk of high sodium intake and hypertension.

Atypical hemolytic uremic syndrome after childbirth: a case report

We report a case of atypical hemolytic uremic syndrome (HUS) that occurred after childbirth. A 33-year-old female was admitted to the emergency room, complaining of abdominal pain six days after giving birth to twins. The patient was diagnosed with hemoperitoneum due to hepatic hemangioma rupture and a left lateral hepatectomy was performed. Angioembolization was performed for the accompanying uterine artery bleeding. After that, her kidney function worsened after the 12th day postpartum. Microangiopathic anemia, thrombocytopenia and renal dysfunction were observed. Shiga toxin-producing Escherichia coli was negative in the stool. Plasma ADMATS 13 activity was normal. After transfer to the nephrology department with suspected atypical HUS, the patient underwent fresh frozen plasma (FFP) transfusion with three hemodialysis sessions. The patient improved without additional dialysis, but a renal biopsy was performed because of persistent proteinuria. Renal pathologic findings were compatible with thrombotic microangiopathy. A genetic test for atypical HUS revealed variants of uncertain significance in the complement factor H related (CFHR) 4 gene and the presence of CFHR3-CFHR1 copy number gain. The CFHR3-CFHR1 copy number gain found in this case is a rare causative mutation of atypical HUS. This case suggests that genetic testing of atypical HUS should include analysis of CFH-CFHR rearrangements as well as general screening for complement-associated genes.

Incidence and risk factors for osteoporotic fractures in patients with systemic lupus erythematosus versus matched controls

BACKGROUND/AIMS

Despite recent improvements in the quality of life of patients with systemic lupus erythematosus (SLE), osteoporosis, and osteoporotic fractures are one of the major complications of SLE. Furthermore, limited data are available on the incidence and predictor of osteoporotic fractures in Korean patients with SLE. Herein, we aimed to assess the incidence and risk factors for osteoporotic fractures in Korean SLE patients compared to those without SLE.

METHODS

SLE patients aged ≥ 40 years (n = 10,434; mean age, 51.3 ± 9.1 years; women, 89.7%) were selected from the Korean National Health Insurance Service database, spanning a period from 2008 to 2014. Age- and sex-matched controls (n = 52,170) were randomly sampled in a 5:1 ratio from non-SLE individuals. The primary outcome was the first occurrence of osteoporotic fracture.

RESULTS

The incidence of osteoporotic fractures was significantly higher in the SLE patients (19.085 per 1,000 person-years) than in matched controls (6.530 per 1,000 person-years). According to the multivariable Cox proportional analysis, patients with SLE exhibited a higher osteoporotic fracture rate than the control group (hazards ratio, 2.964; 95% confidence interval, 2.754 to 3.188), even after adjustment for confounding variables. In the subgroup analysis, male SLE patients or SLE patients aged 40 to 65 years were associated with a higher osteoporotic fracture rate than women SLE patients or SLE patients aged ≥ 65 years, respectively.

CONCLUSION

We found a 2.964-fold increased risk of osteoporotic fracture in SLE patients compared to age- and sex-matched non-SLE controls. Male or middle-aged SLE patients had a relatively higher fracture risk among patients with SLE.

A Case Report of Very Severe Hyperphosphatemia (19.3 mg/dL) in a Uremic Patient Taking Honey and Persimmon Vinegar

We report a case of severe hyperphosphatemia in advanced CKD with poor compliance. A 55-year-old male patient with underlying type 2 diabetes mellitus, hypertension, and chronic kidney disease presented emergently with general weakness and altered mental status. The creatinine level was 14 mg/dL (normal range: 0.5-1.3 mg/dL) 2 months prior to consultation, and he was advised initiation of hemodialysis, which he refused. Subsequently, the patient stopped taking all prescribed medications and self-medicated with honey and persimmon vinegar with the false belief it was detoxifying. At the time of admission, he was delirious, and his laboratory results showed blood urea nitrogen level of 183.4 mg/dL (8-23 mg/dL), serum creatinine level of 26.61 mg/dL (0.5-1.3 mg/dL), serum phosphate level of 19.3 mg/dL (2.5-5.5 mg/dL), total calcium level of 4.3 mg/dL (8.4-10.2 mg/dL), vitamin D (25(OH)D) level of 5.71 ng/mL (30-100 ng/mL) and parathyroid hormone level of 401 pg/ml (9-55 pg/mL). Brain computed tomography revealed non-traumatic spontaneous subdural hemorrhage, presumably due to uremic bleeding. Emergent hemodialysis was initiated, and hyperphosphatemia and hypocalcemia were rectified; calcium acetate and cholecalciferol were administered. The patient’s general condition and laboratory results improved following dialysis. Strict dietary restrictions with patient education were implemented. Multifaceted interventions, including dietary counseling, administration of phosphate-lowering drugs, and lifestyle modifications, should be implemented when encountering patients with CKD, considering the extent of the patient’s adherence.

Molecular insights into the development of hepatic metastases in colorectal cancer: a metastasis prediction study

OBJECTIVE

Colorectal cancer is presently the third most commonly diagnosed cancer in the United States. In this study, we identified molecular differences between hepatic and non-hepatic metastases in colorectal cancer and evaluated their prognostic significance.

MATERIALS AND METHODS

We downloaded primary data from the NCBI Gene Expression Omnibus (GSE6988, GSE62321, GSE50760, and GSE28722). To identify the molecular differences, we used the Significance Analysis of Microarray method. We selected nine prognostic genes (SYTL2, PTPLAD1, CDS1, RNF138, PIGR, WDR78, MYO7B, TSPAN3, and ATP5F1) with hepatic metastasis prediction score in colorectal cancer (hereafter referred to as LASSO Score). We confirmed the prognostic significance of the LASSO Score by using Kaplan-Meier survival analysis, multivariate analysis, the time-dependent area under the curve (AUC) of Uno's C-index, and the AUC of the receiver operating characteristic curve at 1-5 years.

RESULTS

Survival analysis revealed that a high LASSO Score is associated with a poor prognosis in colorectal cancer patients with hepatic metastases (p = 0). Analysis of C-indices and AUC values from the receiver operating characteristic curve further supported this prediction by the LASSO Score. Multivariate analysis confirmed the prognostic significance of the LASSO Score (p = 1.13e-06).

CONCLUSIONS

This study reveals the biological mechanisms underlying hepatic metastases in colorectal cancer and will help in developing targeted therapies for colorectal cancer.

Treatment of hyperlipidemia with proprotein convertase subtilisin/kexin type 9 inhibitor in a patient with nephrotic syndrome: a case report

We report the case of a patient with nephrotic syndrome and toxic epidermal necrolysis (TEN) caused by statin use. The associated hyperlipidemia was controlled using proprotein convertase subtilisin/ kexin type 9 (PCSK9) inhibitors. This is a unique case of treating hyperlipidemia with PCSK9 inhibitor in patient with nephrotic syndrome with TEN. A 54-year-old woman was admitted owing to generalized edema. She had massive proteinuria and was diagnosed with minimal change disease through kidney biopsy. Statins were used for treatment of hyperlipidemia associated with nephrotic syndrome; however, she developed a skin rash, which progressed to TEN. After discontinuation of statins, her skin symptoms improved; however, hyperlipidemia persisted. Because statins could not be administered, we injected evolocumab, a PCSK9 inhibitor, every 2 weeks. Since then, hyperlipidemia has been well controlled without any side effects. Thus, PCSK9 inhibitors may be a good alternative to control hyperlipidemia in patients with statin intolerance or serious side effects.

Extremely Severe Hypernatremia Caused by Wrong Belief in a Patient with Cervical Cancer

A 56-year old female patient who was undergoing follow-up for cervical cancer in our oncology center was presented to the emergency center with anxiety and excessive thirst. The initial serum sodium level of the patient exceeded 200mEq/L, rising up to 238mEq/L during hospitalization. The extremely severe hypernatremia was caused by patient's wrong belief that bay salt would cure the cancer. The patient was treated with hypotonic solution and finally with appropriate hydration, she was fully recovered without any neurological complications.

Association of Hypertension and Blood Pressure With Kidney Cancer Risk: A Nationwide Population-Based Cohort Study

Data regarding health behavior-related factors and systolic or diastolic blood pressure to evaluate the association between blood pressure and kidney cancer are lacking. Using nationally representative data from the Korean National Health Insurance System, 9 746 445 participants without kidney cancer between January 1, 2006 and December 31, 2009 were followed up until December 31, 2017 to obtain data regarding cancer incidence. Participants were categorized, according to blood pressure, as normal (<120/80 mm Hg), elevated (120-129/<80 mm Hg), and hypertensive (≥130/80 mm Hg) with or without antihypertensive medication, according to the 2017 American College of Cardiology and American Heart Association blood pressure guidelines. Kidney cancer was noted in 11 083 participants during the 8-year follow-up. Participants with hypertension were at higher risk for kidney cancer than those without hypertension. Participants with hypertension using medication had a higher cancer risk than those not using medication and those with elevated blood pressure. The risk of kidney cancer significantly increased with higher systolic or diastolic blood pressure, in a dose-dependent manner, even after adjusting for antihypertensive medication use. Therefore, hypertension and high systolic or diastolic blood pressure, compared with normal blood pressure, were associated with an increased risk of kidney cancer.

P0708ASSOCIATION OF OBESITY WITH KIDNEY CYST GROWTH IN PATIENTS WITH AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE; RESULTS FROM KNOW-CKD COHORT DATA

Background and Aims

Overweight or obese patients with autosomal dominant polycystic kidney disease (ADPKD) are associated with the decline of glomerular filtration rate. However, little is known about the annual rate of change in total kidney volume (TKV) in patients with ADPKD according to the body mass index (BMI) corrected by TKV and total liver volume (TLV).

Method

We analyzed 364 patients with ADPKD from the KoreaN Cohort Study for Outcomes in Patients with Chronic Kidney Disease. We compared the changes in TKV in less than 1-year, 2-years and 4-year follow-up from patients by dividing baseline body mass index (BMI) by 18.5 to 22.9 (normal), 23 to 24.9 (overweight), and &gt; 25 kg/m2 (obesity).

Results

During the 4-year follow-up period, TKV tended to increase statistically with increasing BMI (P = 0.032). Similarly, higher BMI group showed higher TKV than lower BMI group (P = 0.016). Conventional BMI is affected by TKV and TLV in advanced ADPKD patients. Therefore, we reclassified patients by corrected BMI using the adjusted body weight (body weight – TKV – TLV). Although the statistical significances between absolute value of TKV and corrected BMI groups were disappeared during the follow-up, TKV% change/year showed significantly higher in ADPKD patients with obesity among corrected BMI groups (normal; 20.2%, overweight; 17.6% and obesity; 30.6%, P for trend = 0.022)

Conclusion

Even after correcting the TKV and TVL, obese patients showed a high of TKV% change/year compared to non-obese patients with ADPKD.

P0376EFFECTS OF HYPERURICEMIA ON THE PROGNOSIS OF IGA NEPHROPATHY AND ITS SEX DIFFERENCE

Background and Aims

Hyperuricemia is a potential risk factor for immunoglobulin A nephropathy (IgAN) progression, but its sex-specific effects on IgAN progression remain unclear. This study aimed to determine the effect of serum uric acid on IgAN progression and whether its effect varied according to sex.

Method

A total of 4339 patients were retrospectively analyzed at a university medical school. We assessed the effect of serum uric acid on IgAN progression using Kaplan–Meier survival analyses and Cox proportional hazards models. The study’s primary end point was IgAN progression that was defined as a 50% decline in the estimated glomerular filtration rate or the initiation of dialysis.

Results

On average, the serum uric acid levels were higher in the men than in the women. In the fully adjusted Cox proportional hazards model that considered all subjects, the risk of IgAN progression increased by about 25.6% for every 1 mg/dL increase in the baseline uric acid level. The serum uric acid level was an independent risk factor for IgAN progression in both sexes, but its effect was more pronounced in the women (hazard ratio [HR], 1.383; confidence interval [CI],1.263 to 1.514; P&lt;0.001) than in the men (HR, 1.181; CI, 1.097 to 1.272; P&lt;0.001) (Pinteraction &lt;0.001). A sensitivity analysis involving serum uric acid quartiles generated consistent and robust results.

Conclusion

The serum uric acid level was an independent risk factor for IgAN progression, and its effect was more pronounced among the women compared with that among the men.

P1496TRENDS IN THE INCIDENCE AND PREVALENCE OF END-STAGE RENAL DISEASE PATIENTS WITH HEMODIALYSIS IN ENTIRE KOREAN POPULATION: A NATIONWIDE POPULATION-BASED STUDY

Background and Aims

Data on the epidemiology and temporal trends of end-stage renal disease (ESRD) with hemodialysis are not well established in the entire Korean population. We aimed to estimate the incidence and prevalence of ESRD with hemodialysis in Korea between 2002 and 2017.

Method

Using the National Health Insurance Service database, we analyzed entire Korean population from 2002 to 2017. Hemodialysis patients was identified by using rare incurable disease codes (V001) or prescription of medical fee code of hemodialysis (O7020, O7021). We only included patients who have been maintained hemodialysis more than 90 days from the date of dialysis initiation to exclude short-term dialysis due to acute kidney injury or patients who converted to peritoneal dialysis or kidney transplantation.

Results

During the 16-year follow-up, the number of hemodialysis patients in Korea has steadily increased from 11,251 in 2002 to 67,486 in 2017. The mean age of hemodialysis patients has gradually increased from 55.57±13.31 years in 2002 to 62.13±13.23 years in 2017. Overall, the number of men tended to be somewhat higher than that of women, and the proportion of men increased slightly from 55.56% in 2002 to 58.45% in 2017. The proportion of diabetic patients increased rapidly from 23.84% to 47.84%, and the percentage of hyperlipidemic patients rose from 18.9% to 86.7%, while the percentage of hypertensive patients did not show a significant increase. The number of incident hemodialysis patients increased significantly from 4,406 in 2003 to 12,134 in 2014 and then decreased to 8,090 in 2017. In the incident patients, the increase in the proportion of male patients and the increase in diabetes and hyperlipidemia were observed in similar manner with prevalent patients.

Conclusion

The incidence and prevalence of hemodialysis in Korea gradually increased from 2002 to 2017. The proportion of men, diabetes and hyperlipidemia among patients with hemodialysis also increased continuously. These findings may contribute as groundwork for epidemiological studies of hemodialysis in Korea.

P0378SERUM URIC ACID IS ASSOCIATED WITH PROGNOSIS OF LUPUS NEPHRITIS IN FEMALE BUT NOT IN MALE

Background and Aims

Lupus nephritis (LN) is one of the major complications of systemic lupus erythematosus. Early intervention in lupus nephritis is known to benefit patients' prognosis. Recent studies have found an association between hyperuricemia and lupus nephritis, but the sex-specific role of uric acid in lupus nephritis remains unclear. The purpose of this study is to elucidate the relationship between lupus nephritis and hyperuricemia, and to investigate sex differences.

Method

We retrospectively analyzed 394 patients who diagnosed with LN by renal biopsy. We assessed the effect of serum uric acid on progression of LN using Kaplan–Meier survival analyses and Cox proportional hazards models. The study’s primary end point was LN progression that was defined as the initiation of dialysis.

Results

The male had a higher mean of serum uric acid level than female. In the overall patient analysis, every 1 mg / dL increase in baseline uric acid level increased the risk of LN progression by about 16.9%. The serum uric acid level was an independent risk factor for LN progression in female (hazard ratio [HR], 1.177; confidence interval [CI],1.024 to 1.353; P&lt;0.001) but not in male (HR, 1.0351; CI, 0.661 to 1.622; P = 0.880). A sensitivity analysis involving serum uric acid tertile generated consistent and robust results.

Conclusion

The serum uric acid level was an independent risk factor for LN progression in female but no in male.

Trend of prevalence and incidence of systemic lupus erythematosus in South Korea, 2005 to 2015: a nationwide population-based study

BACKGROUND/AIMS

The aim of this study was to evaluate the trend of incidence and prevalence of systemic lupus erythematosus (SLE) in South Korea from 2005 to 2015.

METHODS

From 2005 to 2015, individuals with SLE were identified from the National Health Insurance database, which records information on almost all Koreans. SLE was defined according to the International Classification of Diseases, 10th revision (ICD-10), code M32. The incidence was calculated per 100,000 person-years. The prevalence was calculated per 100,000 people and stratified by year, age group, sex, region, and income.

RESULTS

The annual prevalence of SLE increased slightly from 21.25/100,000 people in 2005 to 35.45/100,000 people in 2015. In contrast, the annual incidence of SLE decreased slightly from 5.42/100,000 person-years in 2005 to 3.6/100,000 person-years in 2015. The prevalence and incidence of SLE were 10- and 6-fold higher in women than in men, respectively. The peak age of prevalence and incidence was 30 to 39 years in 2005; in 2015, the peak age of prevalence was 30 to 49 years and of incidence was 20 to 49 years. Regional variation was observed in both incidence and prevalence of SLE. Jeju province showed the highest prevalence of SLE (44.54/100,000 person-years), and Gwangju province showed the highest incidence of SLE (6.98/100,000 person-years) in 2015. The income status did not affect the prevalence or incidence of SLE except in patients without income who received medical aid.

CONCLUSION

The incidence of SLE has declined, but the prevalence has increased in Korea in recent years. Peak age of SLE trend to right shift in Korea.