Incident Chronic Kidney Disease Stage Research Articles

#1432 Prevalence, risks and treatment of incident chronic kidney disease stage 3-4: an observational study in Finland between 2016-2022

Abstract Background and Aims The rising burden of chronic kidney disease (CKD) calls for early detection and targeted interventions. Kidney-protective treatments (renin–angiotensin system inhibitors [RASis] and sodium-glucose co-transporter-2 inhibitors [SGLT2is]) can delay chronic kidney disease (CKD) progression, cardiovascular events and death. However, contemporary differences between CKD patients with and without type 2 diabetes (T2D) is limited. This study aimed to describe the prevalence, patient characteristics, the use of kidney protective treatments (RASi or SGLT2i) and event risks among patients with incident stage 3-4 CKD in Finland. Method We used comprehensive real-world clinical data from electronic health records from primary and hospital care in five municipalities in Finland between 1st January 2016 to 31st December 2022 to identify stage 3-4 CKD patients aged ≥18 years, defined as having either one estimated glomerular filtration rate (eGFR) measurement between 15 to 60 ml/min/1.73 m2 followed by a second one ≥90 days apart, or a registered CKD diagnosis. Two cohorts from primary care were identified: a prevalent cohort indexed at a fixed date, 1st Jan 2022 and an incident cohort indexed at the date of new CKD. The incident CKD patients were followed from CKD incident index date until death, emigration, or end of study on 31 December 2022. Analyses were also stratified by CKD patients with T2D and non-diabetes (T1D and gestational diabetes excluded), respectively. Risks were estimated as event rates per 1000 patient-years. The proportion of patients on/off treatment were estimates as a function of time and divided into pre- vs. post-index. Results In 2022 the prevalent cohort of 16,380 CKD stage 3-4 patients, represented a prevalence of 6.2% in the total background population of 263,383 individuals. The 12,129 incident Stage 3-4 CKD patients had a median eGFR of 55 ml/min/1.73 m2, similar in both non-T2D and T2D. Most patients were non-T2D; 73% (n = 8859). At index, 1.7% had a CKD diagnosis, lower in non-T2D (1.0%) vs T2D (3.5%) patients. The use of urine albumin creatinine ratio (UACR) was generally very low (21% had a measurement), 9% in the non-T2D and 53% in the T2D patients. Non-T2D, compared to T2D patients, were similar in age (76 vs 75 years) and had slightly less comorbidities like HF (12% vs 18%), myocardial infarction (9% vs 14%), stroke (15% vs 16%), atrial fibrillation (21% vs 25%) and less treated with statins (38% vs 64%). During follow-up, 10% had died within 1-year (97 deaths per 1000 patient years), similar in non-T2D (95 deaths per 1000 patient years) and T2D patients (104 deaths per 1000 patient years). One year risk of any hospitalization was also high, 49% and 64%, respectively. The use of kidney-protective treatments (renin angiotensin system inhibitor [RASi] or SGLT2i) at index (date of incident CKD) was lower in patients without T2D (47%) compared to those with T2D (69%). No change was observed in their use in the 12 months after incident CKD (Fig.). Finally, when studying the proportion of all non-T2D patients receiving SGLT2i after approval for CKD treatment, less than 1% of all CKD patients in the study group were treated with SGLT2i on 31st December 2022. Conclusion This study shows that CKD stage 3-4 is highly prevalent in Finland. Newly detected CKD stage 3-4 patients were little diagnosed and the use of UACR was low, especially among those who were non-diabetic. More than 2 out of 3 CKD patients were non-diabetic. Importantly, these non-diabetic CKD patients had similarly high disease burden, similar high risk of dying and had less kidney/cardiovascular prevention compared to those with T2D. The high mortality risks, substantial kidney-protective treatment inertia and UACR underutilization in stage 3-4 CKD patients all call for an urgent need for improved awareness and risk management, especially in the larger group of non-T2D.

Acute Kidney Injury and Subsequent Kidney Failure With Replacement Therapy Incidence in Older Adults With Advanced CKD: A Cohort Study of US Veterans

Advanced age is a major risk factor for chronic kidney disease (CKD) development, which has high heterogeneity in disease progression. Acute kidney injury (AKI) hospitalization rates are increasing, especially among older adults. Previous AKI epidemiologic analyses have focused on hospitalized populations, which may bias results toward sicker populations. This study examined the association between AKI and incident kidney failure with replacement therapy (KFRT) while evaluating age as an effect modifier of this relationship. Retrospective cohort study. 24,133 Veterans at least 65 years old with incident CKD stage 4 from 2011 to2013. AKI, AKI severity, and age. KFRT and death. The Fine-Gray competing risk regression was used to model AKI and incident KFRT with death as a competing risk. A Cox regression was used to model AKI severity and death. Despite a nonsignificant age interaction between AKI and KFRT, a clinically relevant combined effect of AKI and age on incident KFRT was observed. Compared with our oldest age group without AKI, those aged 65-74 years with AKI had the highest risk of KFRT (subdistribution HR [sHR], 14.9; 95% CI, 12.7-17.4), whereas those at least 85 years old with AKI had the lowest (sHR, 1.71; 95% CI, 1.22-2.39). Once Veterans underwent KFRT, their risk of death increased by 44%. A 2-fold increased risk of KFRT was observed across all AKI severity stages. However, the risk of death increased with worsening AKI severity. Our study lacked generalizability, was restricted to ever use of medications, and used inpatient serum creatinine laboratory results to define AKI and AKI severity. In this national cohort, advanced age was protective against incident KFRT but not death. This is likely explained by the high frequency of deaths observed in this population (51.1%). Nonetheless, AKI and younger age are substantial risk factors for incident KFRT.

Risk factor analysis for a rapid progression of chronic kidney disease.

Chronic kidney disease (CKD) is a growing global health concern. Identifying individuals in routine clinical care with new onset CKD at high risk of rapid progression of the disease is imperative to guide allocation of prophylactic interventions, but community-based data are limited. We aimed to examine the risk of rapid progression, kidney failure, hospitalisation and death among adults with incident CKD stage G3 and to clarify the association between predefined risk markers and rapid CKD progression. Using plasma creatinine measurements for the entire Danish population from both hospitals and primary care, we conducted a nationwide, population-based cohort study, including adults in Denmark with incident CKD stage G3 in 2017-2020. We estimated 3-year risks of rapid progression (defined by a confirmed decline in estimated glomerular filtration rate of ≥5ml/min/1.73 m2/year), kidney failure, all-cause hospitalisation and death. To examine risk markers, we constructed a heat map showing the risk of rapid progression based on predefined markers: albuminuria, sex, diabetes and hypertension/cardiovascular disease. Among 133443 individuals with incident CKD stage G3, the 3-year risk of rapid progression was 14.6% (95% confidence interval (CI): 14.4-14.8). The 3-year risks of kidney failure, hospitalisation and death were 0.3% (95% CI: 0.3-0.4), 53.3% (95% CI: 53.0-53.6) and 18.1% (95% CI: 17.9-18.4), respectively. In the heat map, the 3-year risk of rapid progression ranged from 7% in females without albuminuria, hypertension/cardiovascular disease or diabetes, to 46-47% in males and females with severe albuminuria, hypertension/cardiovascular disease and diabetes. This population-based study shows that CKD stage G3 is associated with considerable morbidity in a community-based setting and underscores the need for optimised prophylactic interventions among such patients. Moreover, our data highlight the potential of using easily accessible markers in routine clinical care to identify individuals who are at high risk of rapid progression.

#3901 PROGRESSION OF INCIDENT CHRONIC KIDNEY DISEASE: A DANISH NATIONWIDE POPULATION-BASED COHORT STUDY

Abstract Background and Aims The increasing global burden of kidney failure calls for targeted interventions to slow progression of chronic kidney disease (CKD). However, the understanding of progression from CKD stage G3 is limited. We aimed to characterise individuals with incident CKD stage G3 in Denmark and to examine CKD progression defined by three different measures. Method We conducted a nationwide, population-based cohort study using routinely collected individual-level data from national health and administrative databases in Denmark (population ∼5.9 million). Using creatinine tests performed in general practice and the outpatient hospital setting from 1 January 2017 to 31 December 2020, we included all adults in Denmark with incident CKD stage G3, based on the Kidney Disease: Improving Global Outcomes (KDIGO) criteria (≥2 creatinine measurements corresponding to an estimated glomerular filtration rate (eGFR) between 30-59 ml/min/1.73 m2 separated by ≥90 days). We used the 2009 CKD Epidemiology Collaboration Creatinine Equation for calculating eGFR. The three years leading up to the study period comprised a washout period to minimise inclusion of individuals with prevalent CKD. We explored CKD progression based on three outcome measures of different sensitivity, including 1) rapid CKD progression (decline in eGFR of ≥5 ml/min/1.73 m2/year, that is, for each eGFR measurement taken during follow-up, we considered this and the measurements taken in the prior year (requiring ≥3 eGFR measurements separated by ≥90 days)); 2) drop in GFR category (drop between GFR categories, 45–59 [G3a], 30–44 [G3b], 15–29 [G4], <15 [G5] ml/min/1.73 m2, accompanied by ≥25% drop in eGFR from baseline); and 3) kidney failure (≥2 eGFR measurements <15 ml/min/1.73 m2 separated by ≥90 days and/or kidney replacement therapy). The 1- and 3-year risks of CKD progression according to the three definitions and all-cause mortality were examined as cumulative incidences using the Aalen-Johansen method. Results We included 133,443 individuals with incident CKD stage G3. The median age at inclusion was 75 years (interquartile range (IQR): 69-82) and 55% were females with 59% having hypertension, 18% having diabetes and 10% having heart failure. The median eGFR at inclusion was 56 ml/min/1.73 m2 (IQR: 51-58) and the median number of eGFR measurements was 3 (IQR: 2-5) in the prior year. Among the 133,443 individuals with incident CKD stage G3, 48,997 (37%) fulfilled the criteria for rapid CKD progression at inclusion. Among the 84,446 individuals without rapid progression on the day of inclusion, the 1- and 3-year risks of rapid CKD progression were 25.0% (95% confidence interval (CI): 24.7-25.3) and 46.0% (95% CI: 45.6-46.4), respectively. The risk of a drop in GFR category was 6.9% (95% CI: 6.8-7.1) after 1 year and 16.6% (95% CI: 16.4-16.8) after 3 years. The risks of kidney failure/renal replacement therapy were 0.1% (95% CI: 0.1-0.1) and 0.3% (95% CI: 0.3-0.4) after 1 and 3 years, respectively. All-cause mortality was 6.8% (95% CI: 6.7-6.9) in the first year and the 3-year mortality was 18.1% (95% CI: 17.9-18.4) (Table 1). Conclusion This nationwide, population-based cohort study showed that a substantial proportion of individuals experienced rapid CKD progression in the 3 years following incident CKD stage G3, whereas the risk of drop in GFR category was considerably lower. Kidney failure within 3 years was rare, while all-cause mortality was relatively modest, taking the high average age into account. This highlights the potential for preventive interventions in patients at risk of rapidly deteriorating kidney function, who might benefit from regular monitoring and targeted treatment.

Age-Related Association between Multimorbidity and Mortality in US Veterans with Incident Chronic Kidney Disease

Introduction: Mortality is an important long-term indicator of the public health impact of chronic kidney disease (CKD). We investigated the role of individual comorbidities and multimorbidity on age-specific mortality risk among US veterans with new-onset CKD. Methods: The cohort included 892,005 veterans aged ≥18 years with incident CKD stage 3 between January 2004 and April 2018 in the US Veterans Health Administration (VHA) system and followed until death, December 2018, or up to 10 years. Incident CKD was defined as the first-time estimated glomerular filtration rate (eGFR) was <60 mL/min/1.73 m² for >3 months. Comorbidities were ascertained using inpatient and outpatient clinical records in the VHA system and Medicare claims. We estimated death rates for any cardiovascular disease (CVD, a composite of 6 CVD conditions) and 15 non-CVD comorbidities, and adjusted risks of death (hazard ratio [HR], 95% confidence interval [CI]) overall and by age group at CKD incidence. Results: At CKD incidence, the mean age was 72 years, and 97% were male; the mean eGFR was 52 mL/min/1.73 m², and 95% had ≥2 comorbidities (median, 4) in addition to CKD. During a median follow-up of 4.5 years, among the 16 comorbidities, CVD was associated with the highest relative risk of death in younger veterans (HR 1.96 [95% CI: 1.61–2.37] in ages 18–44 years and HR 1.66 [1.63–1.70] in ages 45–64 years). Dementia was associated with the highest relative risk of death among older veterans (HR 1.71 [1.68–1.74] in ages 65–84 years and HR 1.69 [1.65–1.73] in ages 85–100 years). The additive effect of multimorbidity on risk of death was stronger in younger than older veterans. Compared to having 1 or no comorbidity at CKD onset, the risk of death with ≥5 comorbidities was >7-fold higher among veterans aged 18–44 years and >2-fold higher among veterans aged 85–100 years. Conclusion: The large burden of comorbidities in US veterans with newly identified CKD places them at the risk of premature death. Compared with older veterans, younger veterans with multiple comorbidities, particularly with CVD, at CKD onset are at an even higher relative risk of death.

Urine Biomarkers of Kidney Tubule Health and Incident CKD Stage 3 in Women Living With HIV: A Repeated Measures Study

Rationale & ObjectiveSingle measurements of urinary biomarkers reflecting kidney tubule health are associated with chronic kidney disease (CKD) risk in HIV infection, but the prognostic value of repeat measurements over time is unknown.Study DesignCohort study.Setting & Participants647 women living with HIV infection enrolled in the Women’s Interagency Health Study.Exposures14 urinary biomarkers of kidney tubule health measured at 2 visits over a 3-year period.OutcomeIncident CKD, defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 at two 6-month visits and an average eGFR decline ≥ 3% per year.Analytical ApproachWe used multivariable generalized estimating equations adjusting for CKD risk factors to evaluate baseline, time-updated, and change-over-time biomarker associations with incident CKD. We compared CKD discrimination between models with and without a parsimoniously selected set of biomarkers.ResultsDuring a median 7 years of follow-up, 9.7% (63/647) developed CKD. In multivariable-adjusted analyses, 3 of 14 baseline biomarkers associated with incident CKD. In contrast, 10 of 14 time-updated biomarkers and 9 of 14 biomarkers modeled as change over time associated with incident CKD. Urinary epidermal growth factor (EGF), α1-microglobulin (A1M), and albumin were selected using penalized regression methods. In the time-updated model, lower urinary EGF (risk ratio [RR] per 2-fold higher time-updated biomarker levels, 0.69; 95% CI, 0.58-0.81), higher urinary A1M (RR, 1.47; 95% CI, 1.25-1.73), and higher urinary albumin excretion (RR, 1.21; 95% CI, 1.03-1.42) were jointly associated with increased risk for CKD. Compared with a base model (C statistic, 0.75), CKD discrimination improved after adding urinary EGF, A1M, and albumin values across baseline (C = 0.81), time-updated (C = 0.83), and change-over-time (C = 0.83) models (P < 0.01 for all).LimitationsObservational design, incident CKD definition limited to eGFR.ConclusionsRepeat urinary biomarker measurements for kidney tubule health have stronger associations with incident CKD compared with baseline measurements and moderately improve CKD discrimination in women living with HIV infection.

Non-alcoholic fatty liver disease and risk of incident chronic kidney disease: an updated meta-analysis

ObjectiveStudies reported a significant association between non-alcoholic fatty liver disease (NAFLD) and increased risk of chronic kidney disease (CKD). However, whether this risk changes with increasing severity of NAFLD remains...

Association of Volume Overload With Kidney Function Outcomes Among Patients With Heart Failure With Reduced Ejection Fraction

IntroductionIn patients with heart failure with reduced ejection fraction (HFrEF), volume overload is associated with mortality. Few studies that have examined the relation between volume and long-term kidney function outcomes in HFrEF.MethodsUsing data from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST) trial, we used multivariable Cox regression models to evaluate the association between volume overload as evaluated by B-type natriuretic peptide (BNP) and N-terminal pro B-type natriuretic peptide (NT-proBNP), and a clinical congestion score (scale of 0–12) composed of pedal edema, jugular venous distension, rales, and orthopnea with the occurrence of estimated glomerular filtration rate (eGFR) decline by >40%, and incident chronic kidney disease (CKD) stage ≥4 defined by eGFR of <30 ml/min per 1.73 m2, over a median 10-month follow-up.ResultsAmong 3718 patients (mean eGFR 59 ± 22 ml/min per 1.73 m2), 340 (9%) reached an eGFR decline >40% and 337 (10%) developed incident CKD stage ≥4. In multivariable models, compared with those in the quartile of lowest NT-proBNP, those within the highest quartile had a significantly higher risk of eGFR decline by >40% (hazard ratio [HR] = 2.62 [95% confidence interval {CI} = 1.62, 4.23]) and incident CKD stage ≥4 (HR = 2.66 [95% CI = 1.49, 4.77]), with similar trends for BNP. Similarly in multivariable models, patients in the quartile of highest congestion score had a 48% increased risk for eGFR decline by >40% (HR = 1.48 [95% CI = 1.07, 2.06]) and a 42% increased risk for CKD stage ≥4 (HR = 1.42 [95% CI = 1.01, 1.99]), compared with the lowest quartile.ConclusionVolume overload, as indicated both by elevated natriuretic peptides and clinical signs and symptoms, is associated with increased risk for clinically important kidney function outcomes in HFrEF.

Low birth weight is associated with decline in renal function in Japanese male and female adolescents.

Low birth weight (LBW) is a risk factor for chronic kidney disease (CKD) in later life and is becoming increasingly common in developed countries, including Japan. Furthermore, a serial decrease in birth weight has been associated with an increasing prevalence of CKD stage 2 in male Japanese adolescents. Sex-specific differences affect CKD susceptibility, and the association between birth weight and CKD in women, has not been elucidated. In this study, we investigated the sex-specific effect of LBW on renal function. Annual cross-sectional data of 2417 Japanese adolescents (males 1736; females 681), aged 15-16years, were evaluated over 8years (2007-2014). Over the study period, mean birth weights decreased significantly in males (p < 0.01) and females (p < 0.05). Furthermore, both sexes showed significant decrease in estimated glomerular filtration rates corresponding to the birth weight reduction. The prevalence of CKD stage 2 also increased in males (from 26.0 to 32.4%, p < 0.01) and females (from 6.3 to 18.5%, p < 0.05). The incidence of CKD stage 2 was significantly related to history of LBW (males: odds ratio 1.73; 95% confidence interval 1.06-2.80; p < 0.05; females: odds ratio 3.29; 95% confidence interval 1.25-8.02; p < 0.05). Our data revealed that renal function and birth weight have decreased over time, in healthy Japanese adolescents. In view of the recent declining trend demonstrated by birth weight in Japan, we speculate that the prevalence of CKD might increase in the future.

Initiation of sodium polystyrene sulphonate and the risk of gastrointestinal adverse events in advanced chronic kidney disease: a nationwide study.

BackgroundDespite long-standing clinical use of sodium polystyrene sulphonate (SPS) for hyperkalaemia management in chronic kidney disease (CKD), its safety profile remains poorly investigated.MethodsWe undertook an observational analysis of nephrology-referred adults with incident CKD Stage 4+ in Sweden during 2006–16 and with no previous SPS use. We studied patterns of use and adverse events associated to SPS initiation during follow-up. Patterns of SPS use were defined by chronicity of treatment and by prescribed dose. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with SPS initiation (time-varying exposure) for the risk of severe (intestinal ischaemia, thrombosis or ulceration/perforation) and minor (de novo dispensation of laxatives or anti-diarrheal drugs) gastrointestinal (GI) events.ResultsOf 19 530 SPS-naïve patients with CKD, 3690 initiated SPS during follow-up. A total of 59% took SPS chronically, with an average of three dispensations/year. The majority (85%) were prescribed lower dosages than specified on the product label. During follow-up, 202 severe and 1149 minor GI events were recorded. SPS initiation was associated with a higher incidence of severe adverse events [adjusted HR 1.25 95% CI 1.05–1.49)], particularly in those receiving per label doses [1.54 (1.09–2.17)] and mainly attributed to ulcers and perforations. SPS initiation was also associated with higher incidence of minor GI events [adjusted HR 1.11 (95% CI 1.03–1.19)], regardless of dose, and mainly accounted for by de novo dispensation of laxatives.ConclusionsInitiation of SPS in patients with advanced CKD is associated with a higher risk of severe GI complications as well as the initiation of GI-related medications, particularly when prescribed at per label doses.

SAT-174 IMPACT OF BODY MASS INDEX ON RENAL AND MORTALITY OUTCOMES AFTER ACUTE KIDNEY INJURY: A SYSTEMATIC REVIEW

The UK National Institute of Clinical Excellence (NICE) guidelines highlight the need to identify risk factors which may predispose some patients to experience poor long-term outcomes following an episode of acute kidney injury (AKI). Obesity is an independent risk factor for both AKI and chronic kidney disease (CKD) though little is known about the concomitant impacts of body mass index and AKI on outcomes. The aim of this review was to summarise the evidence regarding the role of body mass index (BMI) on long-term renal and mortality outcomes in individuals post-AKI. Systematic literature review of Medline, EMBASE and Scopus until May 2018. Studies in adults with AKI were included if they: examined renal outcomes (renal recovery, incident CKD, CKD progression, or end stage renal disease (ESRD)) or mortality; used AKI defined per an international AKI consensus definition or equivalent; conducted analysis by BMI; and had follow-up of at least 90 days. 6 cohort studies (2 prospective, 4 retrospective) were identified examining the effect of BMI on renal and/or mortality outcomes after an episode of AKI. There was heterogeneity in definitions of AKI and renal recovery. For renal outcomes, no studies were identified that reported on the effect of BMI on the development or progression of CKD or ESRD following an episode of AKI. 3 studies reported on renal recovery at 90 days post AKI, including 1 with a composite end-point of renal non-recovery or death. Defining recovery as independence from renal replacement therapy at 90 days, BMI did not modulate recovery in 2 studies. Using the composite outcome, 1 study observed a lower BMI to be predictive of 90-day renal non-recovery (defined as eGFR ≤60mls/min) or death. For mortality outcomes, a higher BMI consistently exhibited a protective effect for 90-day mortality (3 studies) and 6-month mortality (1 study). Conversely, in the largest study found, and the only to include a non-AKI comparator group, BMI did not modify the risk of mortality 1-year post-AKI. Variations in length of follow-up, study design, analysis methods, and definitions of AKI and renal recovery precluded meta-analysis. The limited evidence suggests that BMI may not influence 90-day renal recovery; however, the impact of BMI on CKD incidence and progression outcomes remain unknown. Findings suggest that a higher BMI may have a beneficial effect on survival after an episode of AKI at 90 days and 6 months though not at 1 year, suggesting the length of follow-up is critical in determining the effect of BMI on survival. Future AKI studies should report BMI to determine if it contributes to the adverse long-term consequences of AKI.

MON-522 Risk of Chronic Kidney Disease (CKD) and Its Progression in Patients with Chronic Hypoparathyroidism (HypoPT)

Background: Chronic hypoparathyroidism (HypoPT) managed with conventional therapy (i.e., oral calcium and active vitamin D) may potentially increase the risk of chronic kidney disease (CKD) stage ≥ 3 and accelerate CKD stage progression, including progression to end stage kidney disease (ESKD) (i.e., CKD stage 5 or dialysis). Methods: A retrospective cohort study was conducted to compare the risk of CKD between chronic HypoPT patients (excluding those receiving parathyroid hormone) and randomly selected non-HypoPT patients over 5 years of follow-up using a large US commercial claims database (Q1 2007 - Q2 2017). The first date of follow-up (i.e., index date) for HypoPT patients was the earliest HypoPT diagnosis date at least 6 months after the initial HypoPT diagnosis and for non-HypoPT patients was the date of a randomly selected medical claim. Patient characteristics at baseline (the 6 months prior to index date) were compared between cohorts. CKD stages were identified by diagnosis codes, estimated glomerular filtration rate (eGFR) lab values (calculated using the CKD-EPI formula), and dialysis procedure codes. Among those free of CKD at baseline, the risk of incident CKD stage ≥ 3 was compared between cohorts using Kaplan-Meier analysis and adjusted Cox proportional hazards models. Adjusting parameters included demographic (age, sex, race, region, and index year) and clinical (heart failure, hypertension, diabetes, and medication use) characteristics at baseline. Similar analyses were conducted for CKD progression to a higher CKD stage and to ESKD, among patients with baseline CKD stages 3 or 4. Results: A total of 8,097 chronic HypoPT and 40,485 non-HypoPT patients were included. Compared to non-HypoPT patients, HypoPT patients were older (58.6 vs. 47.3 years), a higher proportion were female (76.2 vs. 54.4%), and a higher proportion had CKD stages 3-5 (16.4 vs. 3.0%) and stages 3-4 (13.6 vs. 2.6%) at baseline. Among those with baseline CKD stages 3-4, HypoPT patients were younger (70.6 vs. 72.1 years) and a higher proportion were female (67.1 vs. 54.8%) compared to non-HypoPT patients. Kaplan-Meier analyses showed that HypoPT patients had significant increased risk of CKD stage 3 and higher, CKD progression, and progression to ESKD compared to non-HypoPT patients (all p<0.001). The adjusted hazard ratios (HRs) associated with HypoPT vs. non-HypoPT were 2.57 (95% confidence interval [CI]: 2.35, 2.82) for CKD stage ≥ 3, 1.62 (1.29, 2.03) for CKD progression, and 1.95 (1.41, 2.70) for progression to ESKD (all p<0.001). Conclusions: Chronic HypoPT was associated with significant increased risk of CKD stage ≥ 3 and CKD stage progression, including progression to ESKD. Further research is warranted to understand the potential mechanisms for the relationship of chronic HypoPT and its management with these observed risks. Funding: Shire

Risk of chronic kidney disease in patients with gout and the impact of urate lowering therapy: a population-based cohort study

BackgroundAn association between gout and renal disease is well-recognised but few studies have examined whether gout is a risk factor for subsequent chronic kidney disease (CKD). Additionally, the impact of urate-lowering therapy (ULT) on development of CKD in gout is unclear. The objective of this study was to quantify the risk of CKD stage ≥ 3 in people with gout and the impact of ULT.MethodsThis was a retrospective cohort study using data from the Clinical Practice Research Datalink (CPRD). Patients with incident gout were identified from general practice medical records between 1998 and 2016 and randomly matched 1:1 to patients without a diagnosis of gout based on age, gender, available follow-up time and practice. Primary outcome was development of CKD stage ≥ 3 based on estimated glomerular filtration rate (eGFR) or recorded diagnosis. Absolute rates (ARs) and adjusted hazard ratios (HRs) were calculated using Cox regression models. Risk of developing CKD was assessed among those prescribed ULT within 1 and 3 years of gout diagnosis.ResultsPatients with incident gout (n = 41,446) were matched to patients without gout. Development of CKD stage ≥ 3 was greater in the exposed group than in the unexposed group (AR 28.6 versus 15.8 per 10,000 person-years). Gout was associated with an increased risk of incident CKD (adjusted HR 1.78 95% CI 1.70 to 1.85). Those exposed to ULT had a greater risk of incident CKD, but following adjustment this was attenuated to non-significance in all analyses (except on 3-year analysis of women (adjusted HR 1.31 95% CI 1.09 to 1.59)).ConclusionsThis study has demonstrated gout to be a risk factor for incident CKD stage ≥ 3. Further research examining the mechanisms by which gout may increase risk of CKD and whether optimal use of ULT can reduce the risk or progression of CKD in gout is suggested.

The prognostic importance of duration of AKI: a systematic review and meta-analysis

BackgroundAcute kidney injury (AKI), as defined by peak increase in serum creatinine, is independently associated with increased risk of mortality and length of stay. Studies have suggested that the duration of AKI may be an important additional or independent prognostic marker of increased mortality in patients with AKI across clinical settings. We performed a systematic review and meta-analysis of published studies to assess the impact of duration of AKI on outcomes.MethodsVarious bibliographic databases (MEDLINE, Embase, Cochrane Library, CINAHL and Web of Science) were searched through database inception to December 2015. Human, longitudinal studies with patients aged 18 or above describing outcomes of duration of AKI were included. Duration of AKI categorized as “Short” if AKI duration was ≤2 days or labeled as “transient AKI”; “Medium” for AKI durations 3–6 days and “Long” for AKI duration of ≥7 days or “non-recovered”. Various outcomes looked at were Long term mortality, cardiovascular events, chronic kidney disease (CKD).ResultsEighteen studies were deemed eligible for the systematic review. The outcome of long-term mortality with duration of AKI was reported in 8 studies. The pooled Risk Ratio (RR) for long-term mortality generally was higher for longer duration of AKI: short duration of AKI (n = 8 studies, RR 1.42, 95% CI 1.21–1.66), medium duration (n = 4 studies, RR 1.92, 95% CI 1.34–2.75), and long duration (n = 8 studies, RR 2.28, 95% CI 1.77–2.94) duration of AKI. Further, Duration of AKI was independently associated with higher risk of cardiovascular outcomes and incident CKD Stage 3 when stratified within each stage of AKI.ConclusionDuration of AKI was independently associated with long term mortality, cardiovascular(CV) events, and development of incident CKD Stage 3.

Association of Serum Soluble Urokinase Receptor Levels With Progression of Kidney Disease in Children

Conventional methods to diagnose and monitor chronic kidney disease (CKD) in children, such as creatinine level and cystatin C-derived estimated glomerular filtration rate (eGFR) and assessment of proteinuria in spot or timed urine samples, are of limited value in identifying patients at risk of progressive kidney function loss. Serum soluble urokinase receptor (suPAR) levels strongly predict incident CKD stage 3 in adults. To determine whether elevated suPAR levels are associated with renal disease progression in children with CKD. Post hoc analysis of 2 prospectively followed up pediatric CKD cohorts, ie, the ESCAPE Trial (1999-2007) and the 4C Study (2010-2016), with serum suPAR level measured at enrollment and longitudinal eGFR measured prospectively. In the 2 trials, a total of 898 children were observed at 30 (ESCAPE Trial; n = 256) and 55 (4C Study; n = 642) tertiary care hospitals in 13 European countries. Renal diagnoses included congenital anomalies of the kidneys and urinary tract (n = 637 [70.9%]), tubulointerstitial nephropathies (n = 92 [10.2%]), glomerulopathies (n = 69 [7.7%]), postischemic CKD (n = 42 [4.7%]), and other CKD (n = 58 [6.5%]). Total follow-up duration was up to 7.9 years, and median follow-up was 3.1 years. Analyses were conducted from October 2016 to December 2016. Serum suPAR level was measured at enrollment, and eGFR was measured every 2 months in the ESCAPE Trial and every 6 months in the 4C Study. The primary end point of CKD progression was a composite of 50% eGFR loss, eGFR less than 10 mL/min/1.73 m2, or initiation of renal replacement therapy. The primary end point in this study was renal survival, defined as a composite of 50% loss of GFR that persisted for at least 1 month, the start of renal replacement therapy, or an eGFR less than 10 mL/min/1.73 m2. Of the 898 included children, 560 (62.4%) were male, and the mean (SD) patient age at enrollment was 11.9 (3.5) years. The mean (SD) eGFR was 34 (16) mL/min/1.73 m2. The 5-year end point-free renal survival was 64.5% (95% CI, 57.4-71.7) in children with suPAR levels in the lowest quartile compared with 35.9% (95% CI, 28.7-43.0) in those in the highest quartile (P < .001). By multivariable analysis, the risk of attaining the end point was higher in children with glomerulopathies and increased with age, blood pressure, proteinuria, and lower eGFR at baseline. In patients with baseline eGFR greater than 40 mL/min/1.73 m2, higher log-transformed suPAR levels were associated with a higher risk of CKD progression after adjustment for traditional risk factors (hazard ratio, 5.12; 95% CI, 1.56-16.7; P = .007). Patients with high suPAR levels were more likely to have progression of their kidney disease. Further studies should determine whether suPAR levels can identify children at risk for future CKD.

Assessing the risk of incident hypertension and chronic kidney disease after exposure to shock wave lithotripsy and ureteroscopy.

In this study we sought to determine if among individuals with urolithiasis, extracorporeal shock wave lithotripsy (SWL) and ureteroscopy are associated with a higher risk of incident arterial hypertension (HTN) and/or chronic kidney disease (CKD). This was measured in a population-based retrospective study of 11,570 participants with incident urolithiasis and 127,464 without urolithiasis in The Health Improvement Network. Patients with pre-existing HTN and CKD were excluded. The study included 1319 and 919 urolithiasis patients with at least one SWL or URS procedure, respectively. Multivariable Cox regression was used to estimate the hazard ratio for incident CKD stage 3–5 and HTN in separate analyses. Over a median of 3.7 and 4.1 years, 1423 and 595 of urolithiasis participants developed HTN and CKD, respectively. Urolithiasis was associated with a significant hazard ratio each for HTN of 1.42 (95% CI: 1.35, 1.51) and for CKD of 1.82 (1.67, 1.98). SWL was associated with a significant increased risk of HTN 1.34 (1.15, 1.57), while ureteroscopy was not. When further stratified as SWL to the kidney or ureter, only SWL to the kidney was significantly and independently associated with HTN 1.40 (1.19, 1.66). Neither SWL nor ureteroscopy was associated with incident CKD. Since urolithiasis itself was associated with a hazard ratio of 1.42 for HTN, an individual who undergoes SWL to the kidney can be expected to have a significantly increased hazard ratio for HTN of 1.96 (1.67, 2.29) compared to an individual without urolithiasis.

Identification of Incident CKD Stage 3 in Research Studies

In epidemiologic research, incident chronic kidney disease (CKD) commonly is determined by laboratory tests performed at planned study visits. Given the morbidity and mortality associated with CKD, persons with incident disease may be less likely to attend scheduled visits, affecting observed associations. The objective of this study was to quantify loss to follow-up by CKD status and determine whether supplementation with diagnostic code data improves capture of incident CKD. Prospective cohort study. 11,560 participants in the Atherosclerosis Risk in Communities (ARIC) Study underwent continuous surveillance for hospitalizations and death from baseline visit (1996-1999) to follow-up visit (2011-2013). A subset of hospitalizations in Washington County, MD, was used in diagnostic code validation (n=2,540). Baseline demographics and comorbid conditions. Incident CKD stage 3 ascertained by follow-up visit (visit-based definition) or hospitalization surveillance (hospitalization-based definition). Visit-based definition: ≥25% decline from baseline estimated glomerular filtration rate to <60 mL/min/1.73 m2 at follow-up visit; hospitalization-based definition: hospitalization CKD diagnostic code. Of 11,560 participants, 5,951 attended the follow-up visit and 9,264 were hospitalized. Never-hospitalized participants were younger, more often female, and had fewer comorbid conditions; 73.5% attended the follow-up visit. Incident CKD stage 3 occurred in 1,172 participants by the visit-based definition (251 were never hospitalized) and 1,078 participants by the hospitalization-based definition (237 attended the follow-up study visit). Sensitivity of the hospitalization-based CKD definition was 35.5% (95% CI, 31.6%-39.7%); specificity was 95.7% (95% CI, 94.2%-96.8%). Sensitivity was higher with later time period, older participant age, and baseline prevalent diabetes and CKD. A subset of hospitalizations was used for validation; 15-year gap between study visits. The sensitivity of diagnostic code-identified CKD is low and varies by certain factors; however, supplementing a visit-based definition with hospitalization information can increase disease identification during periods of follow-up without study visits.

Does community-wide chronic kidney disease management improve patient outcomes?

The number of patients starting renal replacement therapy (RRT) is increasing in England, as it is worldwide. Improvements in the management of chronic kidney disease (CKD) across communities to alter this trend are a public health priority. We have prospectively studied changes in the incidence and modality of treatment for end-stage renal disease following the introduction of a CKD management programme in the West Midlands region of England. Nephrology service to approximately 700 000 adult population of mixed ethnicity in urban and suburban areas, many with social deprivation. The programme was introduced in stages between 2003 and 2006 and comprised primary care education and financial incentives, personal clinical reports written directly to patients following every consultation, routine laboratory estimated glomerular filtration rate (eGFR) reporting, eGFR graph surveillance to identify and monitor patients at risk, multidisciplinary pre-RRT care and conservative care. Prevalent patients: 10 552 with CKD and 8509 without CKD with diabetes. access to nephrology care, trends in RRT incidence and starting modality, place of death without RRT. Incident count was adjusted for changes in the local adult population recorded in national censuses. Ninety-one per cent of patients aged ≥75 years with incident CKD stage 5 were known to a nephrologist. The population-adjusted incident RRT rate peaked in 2005 and then declined; the proportion starting with transplant, peritoneal dialysis or haemodialysis by arterio-venous fistula increased to 63% by 2012 (P = 0.001 versus 2005). Fifty-two per cent of patients receiving planned conservative care without dialysis died out of hospital. Following the introduction of a community-wide systematic CKD management programme, the population-adjusted incidence of RRT reduced, modality of initiation of RRT improved and a majority of patients receiving planned conservative care without dialysis died out of hospital.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Injury Molecule 1 (KIM-1) as Predictors of Incident CKD Stage 3: The Atherosclerosis Risk in Communities (ARIC) Study

Identifying individuals at risk of chronic kidney disease (CKD) is critical for timely treatment initiation to slow progression of the disease. Neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1) are known biomarkers of acute kidney injury, but it is unknown whether these markers are associated with incident CKD stage 3 in the general population. Matched case-control study. African American and white participants from the Atherosclerosis Risk in Communities (ARIC) Study who at baseline had an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m(2) and urinary albumin-creatinine ratio ≤30 mg/g. 143 controls were matched for age, sex, and race to 143 cases of incident CKD stage 3 after 8.6 years of follow-up. Quartile of NGAL and KIM-1. Incident CKD stage 3 (eGFR <60 mL/min/1.73 m(2) at follow-up and a decrease in eGFR from baseline to follow-up ≥25%). Both NGAL (P = 0.05) and KIM-1 levels (P < 0.001) were correlated positively with baseline urinary albumin-creatinine ratio; neither was associated with baseline eGFR. Participants with NGAL concentrations in the fourth quartile had more than 2-fold higher odds (adjusted OR, 2.11; 95% CI, 0.96-4.64) of incident CKD stage 3 compared with participants in the first quartile after multivariable adjustment (P-trend = 0.03). Adjustment for urinary creatinine and albumin levels resulted in a nonsignificant association (highest quartile adjusted OR, 1.52; 95% CI, 0.64-3.58; P = 0.2). No significant association between KIM-1 level and incident CKD was observed in crude or adjusted models. The relatively small sample size of the study limits precision and power to detect weak associations. Higher NGAL, but not KIM-1, levels were associated with incident CKD stage 3. Adjustment for urinary creatinine and albumin concentration attenuated this association. Additional studies are needed to confirm these findings and assess the utility of urinary NGAL as a marker of CKD risk.

Association of Complete Recovery From Acute Kidney Injury With Incident CKD Stage 3 and All-Cause Mortality

There is a gap of knowledge in the long-term outcomes of patients who have complete recovery of kidney function after an episode of acute kidney injury (AKI). We sought to determine whether complete recovery of kidney function after an episode of AKI is associated with the development of incident stage 3 chronic kidney disease (CKD) and mortality in patients with normal baseline kidney function. Retrospective cohort study. 3,809 patients from an integrated health care delivery system who had a hospitalization between January 1, 1999, and December 31, 2009, with follow-up through March 31, 2010. AKI defined by International Classification of Diseases, Ninth Revision (ICD-9) codes and using the AKI Network (AKIN) definition, with complete recovery defined as a decrease in serum creatinine level to less than 1.10 times the baseline value. Incident stage 3 CKD persistent for 3 months and all-cause mortality. After a median follow-up of 2.5 years, incident stage 3 CKD occurred in 15% and 3% of those with and without AKI, respectively, with an unadjusted HR of 5.93 (95% CI, 4.49-7.84) and HR of 3.82 (95% CI, 2.81-5.19) in propensity score-stratified analyses. Deaths occurred in 35% and 24% of those with and without AKI, respectively, with an unadjusted HR of 1.46 (95% CI, 1.27-1.68). In propensity score-stratified analyses, HR decreased to 1.08 (95% CI, 0.93-1.27). Measurements of albuminuria were not available. Complete recovery of kidney function after an episode of AKI in patients with normal baseline kidney function is associated with increased risk of the development of incident stage 3 CKD, but not all-cause mortality.