The Stockholm CREAtinine Measurements (SCREAM) project: protocol overview and regional representativeness

Adherence and persistence to novel glucose-lowering medications in persons with type 2 diabetes mellitus undergoing routine care

AIMS

To assess adherence and persistence to sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP1-RA), and dipeptidyl peptidase-4 inhibitors (DPP4i) in routine care.

METHODS

Using retrospective healthcare data from the Stockholm region, Sweden, we evaluated new-users of these agents during 2015-2020. We investigated adherence (≥80 % of days covered by an active supply), persistence (no treatment gap ≥ 60 days), and predictors for non-adherence and non-persistence.

RESULTS

We identified 24,470 new-users of SGLT2i (10,743), GLP1-RA (10,315), and/or DPP4i (9,488). Over 2.8 years median follow-up, the proportion demonstrating adherence was higher for SGLT2i (57 %) than DPP4i (53 %, comparison p < 0.001), and for GLP1-RA than DPP4i (54 % vs 53 %, p < 0.001). Similarly, persistence was higher for both SGLT2i and GLP-RA than DPP4i (respectively, 50 % vs 44 %, p < 0.001; 49 % vs 44 %, p < 0.001). Overall adherence was better among users who were older, had a history of high blood pressure, used more non-diabetic medications, had lower Hba1c, had better kidney function, and had completed secondary schooling or university. Women had worse adherence to SGLT2i and GLP1-RA than DPP4i.

CONCLUSIONS

We report adherence and persistence to SGLT2i, GLP1-RA and DPP4i in routine care, and identify prognostic factors that could inform implementation interventions to improve uptake of these important therapies.

The Assessment of the Association of Proton Pump Inhibitor Usage with Chronic Kidney Disease Progression through a Process Mining Approach

Previous studies have suggested an association between Proton Pump Inhibitors (PPIs) and the progression of chronic kidney disease (CKD). This study aims to assess the association between PPI use and CKD progression by analysing estimated glomerular filtration rate (eGFR) trajectories using a process mining approach. We conducted a retrospective cohort study from 1 January 2006 to 31 December 2011, utilising data from the Stockholm Creatinine Measurements (SCREAM). New users of PPIs and H2 blockers (H2Bs) with CKD (eGFR < 60) were identified using a new-user and active-comparator design. Process mining discovery is a technique that discovers patterns and sequences in events over time, making it suitable for studying longitudinal eGFR trajectories. We used this technique to construct eGFR trajectory models for both PPI and H2B users. Our analysis indicated that PPI users exhibited more complex and rapidly declining eGFR trajectories compared to H2B users, with a 75% increased risk (adjusted hazard ratio [HR] 1.75, 95% confidence interval [CI] 1.49 to 2.06) of transitioning from moderate eGFR stage (G3) to more severe stages (G4 or G5). These findings suggest that PPI use is associated with an increased risk of CKD progression, demonstrating the utility of process mining for longitudinal analysis in epidemiology, leading to an improved understanding of disease progression.

Cystatin C should be routinely available for estimating kidney function

PURPOSE OF REVIEW

In this report, we summarize why the availability of cystatin C is important across a variety of clinical scenarios, the recent literature on when, why and in whom cystatin C testing should be considered, and how nephrologists can take practical steps to incorporate cystatin C testing into their practice.

RECENT FINDINGS

Large intra-individual discrepancies between estimated glomerular filtration rate by creatinine (eGFRcr) and estimated glomerular filtration rate by creatinine eGFRcys (known as eGFRdiff) are observed in at least 1 in 4 people. These differences are seen more commonly among more vulnerable individuals: older adults, females, non-White individuals and those living with multiple medical conditions. A large eGFRdiff, where eGFRcys is lower than eGFRcr, is associated with a plethora of adverse outcomes, including medication-associated adverse events, acute kidney injury, cardiovascular disease, kidney failure and all-cause mortality. Among studies that have measured GFR, eGFRcr-cys usually provides the most accurate estimation of kidney function compared to mGFR, including among participants with large discrepancies between eGFRcr and eGFRcys.

SUMMARY

Cystatin C improves sensitivity and specificity of chronic kidney disease diagnosis, improves detection of harmful acute and chronic changes in kidney function, improves precision of treatment eligibility and safety, and may reduce healthcare inequalities. Better education, curiosity, and motivation among nephrologists could substantially improve the availability and utilization of cystatin C.

Establishment and representativeness of the Stockholm Sodium Cohort: A laboratorial and pharmacoepidemiologic database covering 1.6 million individuals in the Stockholm County

OBJECTIVE

Hyponatremia is associated with considerable morbidity and mortality, but causal links have been difficult to establish. Here, we describe the establishment and representativeness of the Stockholm Sodium Cohort (SSC), designed to study etiologies and outcomes of hyponatremia.

STUDY DESIGN AND SETTING

All residents of Stockholm County undertaking at least one serum sodium test between 2005-2018 were included in the SSC. Individual-level test results from over 100 laboratory parameters relevant to hyponatremia were collected and linked to data on demographics, socioeconomic status, healthcare contacts, diagnoses and dispensed prescription medications using national registers.

RESULTS

A total of 1,632,249 individuals, corresponding to 64% of the population of Stockholm County, were included in the SSC. Coverage increased with advancing age, ranging from 32% in children and adolescents (≤18 years) to 97% among the oldest (≥80 years). The coverage of SSC included the vast majority of patients in Stockholm County diagnosed with diabetes mellitus (93%), myocardial infarction (98%), ischemic stroke (97%), cancer (85%), pneumonias requiring inpatient care (95%) and deaths (88%).

CONCLUSION

SSC is the first cohort specifically designed to investigate sodium levels in a large, population-based setting. It includes a wide range of administrative health data and laboratory analyses. The coverage is high, particularly among elderly and individuals with comorbidities. Consequently, the cohort has a large potential for exploration of various aspects of hyponatremia.

A novel risk factor for malignancy: Albuminuria

Cancer is the second leading cause of death among the adult population following cardiovascular diseases. Prevention and earlier diagnosis are among the cornerstones in the management of malignancies. Albuminuria is a diagnostic criterion for chronic kidney disease and has been associated with multiple conditions including cardiovascular diseases and systemic inflammation while the association between albuminuria and malignancy has been inadequately addressed. Large-scale observational studies with long follow-up periods demonstrate a statistically significant association between albuminuria and overall malignancy incidence, especially urothelial malignancy incidence. However, the underlying pathophysiology linking these two entities is not a straightforward causal relationship but most likely a multidirectional relationship including a causal link. In this narrative review, we evaluate the clinical studies investigating the association between albuminuria and malignancy along with potential underlying mechanisms linking them. We also summarize data on the impact of treatment modalities prescribed for albuminuria and/or proteinuria on the prevention or prognosis of malignancies.

Association between incident depression and clinical outcomes in patients with chronic kidney disease

Background

Depression is highly prevalent and related to increased morbidity and mortality in patients on dialysis, but less is known among patients with earlier stages of CKD. This study investigated the associations between depression and clinical outcomes in patients with CKD not receiving dialysis.

Methods

We identified 157 398 adults with CKD stages 3-5 not previously diagnosed with depression from the Stockholm CREAtinine Measurements (SCREAM) project. The primary outcomes included hospitalization, CKD progression (>40% decline in eGFR, initiation of kidney replacement therapy, or death due to CKD), major adverse cardiovascular events (MACE; myocardial infarction, stroke, or cardiovascular death), and all-cause mortality. Survival analyses were used to estimate the associations between incident depression and adverse health outcomes, adjusting for socio-demographics, kidney disease severity, healthcare utilization, comorbidities, and concurrent use of medications.

Results

During a median follow-up of 5.1 (interquartile range: 2.3-8.5) years, 12 712 (8.1%) patients received an incident diagnosis of depression. A total of 634 471 hospitalizations (4 600 935 hospitalized days), 42 866 MACEs, and 66 635 deaths were recorded, and 9795 individuals met the criteria for CKD progression. In the multivariable-adjusted analyses, incident depression was associated with an elevated rate of hospitalized days [rate ratio: 1.77, 95% confidence interval (CI): 1.71-1.83], as well as an increased rate of CKD progression [hazard ratio (HR): 1.38, 95% CI: 1.28-1.48], MACE (HR: 1.22, 95% CI: 1.18-1.27), and all-cause mortality (HR: 1.41, 95% CI: 1.37-1.45). The association with CKD progression was more evident after one year of depression diagnosis (HR: 1.47, 95% CI: 1.36-1.59). Results were robust across a range of sensitivity analyses.

Conclusion

Among patients with nondialysis-dependent CKD stages 3-5, incident depression is associated with poor prognosis, including hospitalization, CKD progression, MACE, and all-cause mortality.

Poor recognition and undertreatment of anemia in patients with chronic kidney disease managed in primary care

BACKGROUND

Anemia is a common complication of chronic kidney disease (CKD), but limited awareness and treatment options may hinder its management among CKD patients followed in primary care.

METHODS

We evaluated adults with CKD stages 3-5 attending primary care in Stockholm, Sweden, 2012-2018. We assessed the incidence of anemia, clinical reactions, and association with subsequent major adverse cardiovascular events (MACE) and death.

RESULTS

We identified 45,637 patients with CKD stages 3-5 free from anemia (mean age 78 years; 64% females; 79% CKD stage 3b). During a median follow-up of 2.4 years, 26% of patients developed anemia, and 10.4% developed severe anemia (hemoglobin <10 g/dL). Within 6 months from the anemia event, iron tests were infrequent; ferritin and transferrin saturation were tested in 27% and 11% of anemia cases, respectively, and 49% and 24% of severe anemia cases. Few patients were recognized with a clinical diagnosis (15% of anemia cases; 68% of severe anemias). Only 19% of patients with anemia received treatment, primarily iron (10%) and blood transfusions (7%); erythropoietin-stimulating agent use was anecdotal (∼1%). Treatment rates for severe anemia were higher, but 43% of patients still failed to receive treatment. Developing anemia was associated with a higher risk of MACE and death.

CONCLUSION

Anemia was common and associated with adverse outcomes among patients with CKD stages 3-5 managed in primary care. Iron stores were infrequently tested, and a large proportion of patients with anemia remained untreated/under-recognized.

Absolute and Relative Risks of Kidney Outcomes Associated With Lithium vs Valproate Use in Sweden

Importance

Among patients with bipolar disorder, discordant findings have been published on the nephrotoxic effects of lithium therapy.

Objective

To quantify absolute and relative risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) in people who initiated lithium compared with valproate therapy and to investigate the association between cumulative use and elevated lithium levels and kidney outcomes.

Design, Setting, and Participants

This cohort study had a new-user active-comparator design and used inverse probability of treatment weights to minimize confounding. Included patients initiated therapy with lithium or valproate from January 1, 2007, to December 31, 2018, and had a median follow-up of 4.5 years (IQR, 1.9-8.0 years). Data analysis began in September 2021, using routine health care data from the period 2006 to 2019 from the Stockholm Creatinine Measurements project, a recurrent health care use cohort of all adult residents in Stockholm, Sweden.

Exposures

New use of lithium vs new use of valproate and high (>1.0 mmol/L) vs low serum lithium levels.

Main Outcomes and Measures

Progression of CKD (composite of >30% decrease relative to baseline estimated glomerular filtration rate [eGFR] and kidney failure), AKI (by diagnosis or transient creatinine elevations), new albuminuria, and annual eGFR decrease. Outcomes by attained lithium levels were also compared in lithium users.

Results

The study included 10 946 people (median [IQR] age, 45 [32-59] years; 6227 female [56.9%]), of whom 5308 initiated lithium therapy and 5638 valproate therapy. During follow-up, 421 CKD progression events and 770 AKI events were identified. Compared with patients who received valproate, those who received lithium did not have increased risk of CKD (hazard ratio [HR], 1.11 [95% CI, 0.86-1.45]) or AKI (HR, 0.88 [95% CI, 0.70-1.10]). Absolute 10-year CKD risks were low and similar: 8.4% in the lithium group and 8.2% in the valproate group. No difference in the risk of developing albuminuria or the annual rate of eGFR decrease was found between groups. Among more than 35 000 routine lithium tests, only 3% of results were in the toxic range (>1.0 mmol/L). Lithium values greater than 1.0 mmol/L, compared with lithium values of 1.0 mmol/L or less, were associated with increased risk of CKD progression (HR, 2.86; 95% CI, 0.97-8.45) and AKI (HR, 3.51; 95% CI, 1.41-8.76).

Conclusions and Relevance

In this cohort study, compared with new use of valproate, new use of lithium was meaningfully associated with adverse kidney outcomes, with low absolute risks that did not differ between therapies. However, elevated serum lithium levels were associated with future kidney risks, particularly AKI, emphasizing the need for close monitoring and lithium dose adjustment.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants

RATIONALE & OBJECTIVE

Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018.

EXPOSURE

Initiation of DOAC or VKA treatment.

OUTCOME

Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism.

ANALYTICAL APPROACH

Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects.

RESULTS

We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m². The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation.

LIMITATIONS

Missing information on time in therapeutic range and treatment dosages.

CONCLUSIONS

Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

Association between cholinesterase inhibitors and kidney function decline in patients with Alzheimer's dementia

Preclinical evidence shows that activation of the cholinergic anti-inflammatory pathway (CAP) may have direct and indirect beneficial effects on the kidney. Cholinesterase inhibitors (ChEIs) are specific Alzheimer's dementia (AD) therapies that block the action of cholinesterases and activate CAP. Here, we explored a plausible effect of ChEIs on slowing kidney function decline by comparing the risk of CKD progression among patients with newly diagnosed AD that initiated ChEI or not within 90 days. Using complete information of routine serum creatinine tests, we evaluated changes in estimated glomerular filtration rate (eGFR) and defined the outcome of chronic kidney disease (CKD) progression as the composite of an eGFR decline of over 30%, initiation of dialysis/transplant or death attributed to CKD. A secondary outcome was death. Inverse probability of treatment-weighted Cox regression was used to estimate hazard ratios. Among 11, 898 patients, 6,803 started on ChEIs and 5,095 did not. Mean age was 80 years (64% women) and the mean eGFR was 68 ml/min/1.73m². During a median 3.0 years of follow-up, and compared to non-use, ChEI use was associated with 18% lower risk of CKD progression (1,231 events, adjusted hazard ratio 0.82; 95% confidence interval 0.71-0.96) and a 21% lower risk of death (0.79; 0.72-0.86). Results were consistent across subgroups, ChEI subclasses and after accounting for competing risks. Thus, in patients with AD undergoing routine care, use of ChEI (vs no-use) was associated with lower risk of CKD progression.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

Removing race from the CKD-EPI equation and its impact on prognosis in a predominantly White European population

BACKGROUND

While American nephrology societies recommend using the 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) equation without a Black race coefficient, it is unknown how this would impact disease distribution, prognosis and kidney failure risk prediction in predominantly White non-US populations.

METHODS

We studied 1.6 million Stockholm adults with serum/plasma creatinine measurements between 2007 and 2019. We calculated changes in eGFR and reclassification across KDIGO GFR categories when changing from the 2009 to 2021 CKD-EPI equation; estimated associations between eGFR and the clinical outcomes kidney failure with replacement therapy (KFRT), (cardiovascular) mortality and major adverse cardiovascular events using Cox regression; and investigated prognostic accuracy (discrimination and calibration) of both equations within the Kidney Failure Risk Equation.

RESULTS

Compared with the 2009 equation, the 2021 equation yielded a higher eGFR by a median [interquartile range (IQR)] of 3.9 (2.9-4.8) mL/min/1.73 m2, which was larger at older age and for men. Consequently, 9.9% of the total population and 36.2% of the population with CKD G3a-G5 was reclassified to a higher eGFR category. Reclassified individuals exhibited a lower risk of KFRT, but higher risks of all-cause/cardiovascular death and major adverse cardiovascular events, compared with non-reclassified participants of similar eGFR. eGFR by both equations strongly predicted study outcomes, with equal discrimination and calibration for the Kidney Failure Risk Equation.

CONCLUSIONS

Implementing the 2021 CKD-EPI equation in predominantly White European populations would raise eGFR by a modest amount (larger at older age and in men) and shift a major proportion of CKD patients to a higher eGFR category. eGFR by both equations strongly predicted outcomes.

The Stockholm CREAtinine Measurements (SCREAM) project: Fostering improvements in chronic kidney disease care

SCREAM (Stockholm CREAtinine Measurements project) was initiated in 2010 in collaboration with the healthcare provider of Stockholm County healthcare to quantify potential medication errors, estimate the burden of chronic kidney disease (CKD) and to illustrate the value of incorporating measures of kidney function into the medical decision process. Because most patients are unaware of their CKD and diagnoses are seldom issued, SCREAM took advantage of the commonness of serum/plasma creatinine testing, which can be used to estimate the glomerular filtration rate (eGFR) and classify the stage of CKD severity. SCREAM is periodically updated, and at present contains healthcare information of all residents in Stockholm region during 2006-2019 (about 3 million people), enriched with a broad range of laboratory measurements for those in whom creatinine or albuminuria has been measured (about 1.8 million people). This health information was linked with national administrative and quality registries via the unique personal identification number of each Swedish citizen, conforming the richest characterization in Sweden of the population's journey through health and disease. This review discusses the context of its creation, strengths and weakness, key findings and plans for the future. We summarize our findings related to the burden of CKD in Sweden, its adverse health risks (such as risk of infections, cancer or dementia) and how underlying kidney function alters the risk-benefit ratio of common medications. Results have had clinical impact and demonstrate the importance of population-based research in the spectrum of clinical research to improve health.

Stopping kidney protection in the elderly following acute kidney injury: think mortality

Chronic kidney disease (CKD) is projected to become the fifth most common global cause of death by 2040. This illustrates a key consequence of CKD, i.e. premature mortality. Since nephroprotective drugs such as renin–angiotensin system (RAS) blockers and sodium–glucose transport protein 2 (SGLT2) inhibitors decrease glomerular hyperfiltration, they may be stopped following an episode of acute kidney injury (AKI). This may theoretically modify the risks of subsequent events, ranging from hyperkalaemia to CKD progression to cardiovascular events, but the evidence so far has been inconsistent. Roemer et al. have now addressed the shortcomings of prior studies. In a population of mostly elderly (median age 78 years) prevalent users of RAS blockers with an indication for this therapy and who survived for at least 3 months after discharge following a hospitalization characterized by moderate to severe AKI, roughly 50% had stopped RAS blockade at 3 months. Stopping RAS blockade was associated with an increased risk of a primary composite outcome of death, myocardial infarction and stroke, of which a large majority (80%) of events were deaths. In contrast, the risk of hyperkalaemia was reduced and the risk of repeated AKI, CKD progression or heart failure hospitalization was unchanged in patients who stopped RAS blockers. These findings call for a re-evaluation of the practice of stopping RAS blockers in the long-term following AKI and suggest that studies are needed regarding similar practices for SGLT2 inhibitors.

Stopping Versus Continuing Renin-Angiotensin System Inhibitors After Acute Kidney Injury and Adverse Clinical Outcomes; An Observational Study From Routine Care Data

Background

The risk–benefit ratio of continuing with renin–angiotensin system inhibitors (RASi) after an episode of acute kidney injury (AKI) is unclear. While stopping RASi may prevent recurrent AKI or hyperkalaemia, it may deprive patients of the cardiovascular benefits of using RASi.

Methods

We analysed outcomes of long-term RASi users experiencing AKI (stage 2 or 3, or clinically coded) during hospitalization in Stockholm and Sweden during 2007–18. We compared stopping RASi within 3 months after discharge with continuing RASi. The primary study outcome was the composite of all-cause mortality, myocardial infarction (MI) and stroke. Recurrent AKI was our secondary outcome and we considered hyperkalaemia as a positive control outcome. Propensity score overlap weighted Cox models were used to estimate hazard ratios (HRs), balancing 75 confounders. Weighted absolute risk differences (ARDs) were also determined.

Results

We included 10 165 individuals, of whom 4429 stopped and 5736 continued RASi, with a median follow-up of 2.3 years. The median age was 78 years; 45% were women and median kidney function before the index episode of AKI was 55 mL/min/1.73 m². After weighting, those who stopped had an increased risk [HR, 95% confidence interval (CI)] of the composite of death, MI and stroke [1.13, 1.07–1.19; ARD 3.7, 95% CI 2.6–4.8] compared with those who continued, a similar risk of recurrent AKI (0.94, 0.84–1.05) and a decreased risk of hyperkalaemia (0.79, 0.71–0.88).

Discussion

Stopping RASi use among survivors of moderate-to-severe AKI was associated with a similar risk of recurrent AKI, but higher risk of the composite of death, MI and stroke.

OUP accepted manuscript

The year 2021 was the last full year of Alberto Ortiz’s editorship at Clinical Kidney Journal (CKJ). On May 2022, Maria José Soler will start her term as the Editor-in-Chief. Over these years, CKJ obtained its first journal impact factor and has consolidated its position among the top journals in the field, consistently ranking among the top 25% (first quartile) journals in Urology and Nephrology. The 2020 journal impact factor rose to 4.45, becoming the top open access journal in Nephrology and the ninth ranked Nephrology journal overall. We now review the recent history of the journal and the most highly cited topics which include the epidemiology of kidney disease, chronic kidney disease topics, such as the assessment and treatment of chronic kidney disease, onconephrology, cardionephrology, glomerular disease, transplantation and coronavirus disease 2019 (COVID-19).

Stopping renin-angiotensin system inhibitors after hyperkalemia and risk of adverse outcomes

BACKGROUND

Stopping renin-angiotensin system inhibitors (RASi) after an episode of hyperkalemia is common but may involve therapeutic compromises, in that the cessation of RASi deprives patients of their beneficial cardiovascular effects.

METHODS AND RESULTS

Observational study from the Stockholm Creatinine Measurements (SCREAM) project including patients initiating RASi in routine care and surviving a first-detected episode of hyperkalemia (potassium >5.0 mmol/L). We used target trial emulation techniques based on cloning, censoring and weighting to compare stopping vs. continuing RASi within 6 months after hyperkalemia. Outcomes were 3-year risks of mortality, major adverse cardiovascular events (MACE, composite of cardiovascular death, myocardial infarction and stroke hospitalization) and recurrent hyperkalemia. Of 5669 new users of RASi who developed hyperkalemia (median age 72 years, 44% women), 1425 (25%) stopped RASi therapy within 6 months. Compared with continuing RASi, stopping therapy was associated with a higher 3-year risk of death (absolute risk difference 10.8%; HR 1.49, 95% CI 1.34-1.64) and MACE (risk difference 4.7%; HR 1.29, 1.14-1.45), but a lower risk of recurrent hyperkalemia (risk difference -9.5%; HR 0.76, 0.69-0.84). Results were consistent for events following potassium of >5.0 or >5.5 mmol/L, after censoring when the treatment decision was changed, across prespecified subgroups, and after adjusting for albuminuria.

CONCLUSION

These findings suggest that stopping RASi after hyperkalemia may be associated with a lower risk of recurrence of hyperkalemia, but higher risk of death and cardiovascular events.

Kidney Function, Kidney Replacement Therapy, and Mortality in Men and Women

Introduction

Women are more likely to have chronic kidney disease (CKD), compared with men, yet they are less likely to receive dialysis. Whether this sex disparity, which has predominantly been observed in nephrology-referred or CKD-specific cohorts so far, has a biological root cause remains unclear.

Methods

We extracted general population data from the Stockholm CREAtinine Measurements project (SCREAM) (N = 496,097 participants, 45.5% men, 54.5% women). We used Cox regression to model male-to-female cause-specific hazard ratios (csHRs) for the competing events kidney replacement therapy (KRT, by dialysis or transplantation) and pre-KRT death, adjusted for baseline age, baseline kidney function (assessed via estimated glomerular filtration rate [eGFR] and eGFR slope), and comorbidities. Furthermore, we modeled sex-specific all-cause mortality by eGFR, again adjusted for age, eGFR slope, and comorbidities at baseline.

Results

Compared with women, men were significantly more likely to receive KRT (fully adjusted male-to-female csHR for KRT 1.41 [95% CI 1.13–1.76]) but also more likely to experience pre-KRT death (csHR 1.36 [95% CI 1.33–1.38]). Differences between men and women regarding all-cause mortality by eGFR indicated a higher mortality in men at low eGFR values.

Conclusion

Our data show that sex differences in CKD outcomes persist even after controlling for important comorbidities and kidney function at baseline. While future studies with a wider range of biological factors are warranted, these data suggest that nonbiological factors may be more important in explaining existing sex disparities in CKD progression and therapy.

Use of nephrotoxic medications in adults with chronic kidney disease in Swedish and US routine care

Background

To characterize the use of nephrotoxic medications in patients with chronic kidney disease (CKD) Stages G3–5 in routine care.

Methods

We studied cohorts of adults with confirmed CKD G3–5 undergoing routine care from 1 January 2016 through 31 December 2018 in two health systems [Stockholm CREAtinine Measurements (SCREAM), Stockholm, Sweden (N = 57 880) and Geisinger, PA, USA (N = 16 255)]. We evaluated the proportion of patients receiving nephrotoxic medications within 1 year overall and by baseline kidney function, ranked main contributors and examined the association between receipt of nephrotoxic medication and age, sex, CKD G-stages comorbidities and provider awareness of the patient's CKD using multivariable logistic regression.

Results

During a 1-year period, 20% (SCREAM) and 17% (Geisinger) of patients with CKD received at least one nephrotoxic medication. Among the top nephrotoxic medications identified in both cohorts were non-steroidal anti-inflammatory drugs (given to 11% and 9% of patients in SCREAM and Geisinger, respectively), antivirals (2.5% and 2.0%) and immunosuppressants (2.7% and 1.5%). Bisphosphonate use was common in SCREAM (3.3%) and fenofibrates in Geisinger (3.6%). Patients <65 years of age, women and those with CKD G3 were at higher risk of receiving nephrotoxic medications in both cohorts. Notably, provider awareness of a patient's CKD was associated with lower odds of nephrotoxic medication use {odds ratios [OR] 0.85[95% confidence interval (CI) 0.80–0.90] in SCREAM and OR 0.80 [95% CI 0.72–0.89] in Geisinger}.

Conclusions

One in five patients with CKD received nephrotoxic medications in two distinct health systems. Strategies to increase physician's awareness of patients’ CKD and knowledge of drug nephrotoxicity may reduce prescribing nephrotoxic medications and prevent iatrogenic kidney injury.

Kidney Disease Cohort (KidDiCo) of Southern Denmark: Design, Coverage, Generalizability and Implications for Use

Background

This article provides a description of a large register of a population from the Region of Southern Denmark, the Kidney Disease Cohort (KiDiCo). Coverage and representativeness according to gender and education level are discussed.

Methods

Data for KiDiCo were obtained using laboratory databases from participating laboratories in the Region of Southern Denmark and were linked to individual personal 10-digit personal identification numbers. The study population includes individuals over 18 years of age living in Denmark, whose serum creatinine was analysed in one of the 27 participating laboratories in the Region of Southern Denmark during the period of 8 years from 1st January 2006 to 31st December 2013. Individually linked data consist of diagnosis codes, date and cause of death, dispensed medicine data, socioeconomic data and demographic data.

Results

In total, n = 669,929 individuals had their blood tested for creatinine between 2007 and 2013 in a defined geographical area. The estimated geographical coverage was 78%. The median age of the background population was 6 years lower. The cohort had a slightly higher percentage of females (53%) compared to the background population (49%). Differences in educational levels reflect the minor age gap.

Conclusion

Based on coverage of 78% together with similar characteristics in terms of gender and age, the KiDiCo is a representative cohort of patients in the Region of Southern Denmark. Combining laboratory data with high-quality Danish administrative registers makes diverse research feasible.

Secondary hyperparathyroidism and adverse health outcomes in adults with chronic kidney disease

BACKGROUND

Secondary hyperparathyroidism (sHPT) develops frequently in patients with chronic kidney disease (CKD). However, the burden and long-term impact of sHPT on the risk of adverse health outcomes are not well studied.

METHODS

We evaluated all adults receiving nephrologist care in Stockholm during 2006-11 who were not undergoing kidney replacement therapy and had not developed sHPT. Incident sHPT was identified by using clinical diagnoses, initiated medications or two consecutive parathyroid hormone (PTH) measurements ≥130 pg/mL. We characterized sHPT incidence by estimated glomerular filtration rate (eGFR) strata, evaluated clinical predictors and quantified the association between incident sHPT (time-varying exposure) and the risk of fractures, CKD progression, major adverse cardiovascular events (MACEs) and death.

RESULTS

We identified 2556 adults with CKD Stages 1-5 (mean age 66 years, 38% women), of whom 784 developed sHPT during follow-up. The incidence of sHPT increased with advancing CKD: from 57 cases/1000 person-years in CKD Stage G3 to 230 cases/1000 person-years in Stage G5. In multivariable analyses, low eGFR was the strongest sHPT predictor, followed by young age, male sex and diabetes. Incident sHPT was associated with a 1.3-fold (95% confidence interval 1.1-1.8) increased risk of death, a 2.2-fold (1.42-3.28) higher risk of MACEs, a 5.0-fold (3.5-7.2) higher risk of CKD progression and a 1.3-fold (1.5-2.2) higher risk of fractures. Results were consistent in stratified analyses and after excluding early events.

CONCLUSIONS

Our findings illustrate the burden of sHPT in advanced CKD and highlight the susceptibility for adverse outcomes of patients developing sHPT. This may inform clinical decisions regarding pre-sHPT risk stratification, PTH monitoring and risk-prevention strategies post-sHPT development.

Patterns of chronic and transient hyperkalaemia and clinically important outcomes in patients with chronic kidney disease

Background

Whether hyperkalaemia in CKD is chronic or transient, and whether this has different outcome implications, is not known.

Methods

This was an observational study of adults with CKD G3–5 from Stockholm, Sweden 2006–11. We examined individual trajectories of potassium from all measurements obtained through routine outpatient care. For each month of follow-up, we created a rolling assessment of the proportion of time in which potassium was abnormal during the previous 12 months. We defined patterns of hyperkalaemia as transient (≤50% of time during the previous year with potassium >5.0 mmol/L) and chronic (>50% of time with potassium >5.0 mmol/L), and examined whether previous hyperkalaemia pattern offers additional predictive value beyond that provided by the most recent (current) potassium value.

Results

We included 36 511 participants (56% women) with CKD G3–5 and median estimated glomerular filtration rate 46 mL/min/1.73 m². Transient and chronic hyperkalaemia, respectively, were observed in 15% and 4% of patients with CKD G3a, and in 50% and 17% of patients with CKD G5. In fully adjusted models, transient (hazard ratio 1.36, 95% confidence interval 1.29–1.46) or chronic (1.16, 1.04–1.32) hyperkalaemia patterns, but not current hyperkalaemia, were associated with major adverse cardiovascular events (MACE), compared with normokalaemia. Transient hyperkalaemia (1.43, 1.35–1.52) and current potassium values, but not chronic hyperkalaemia, were associated with the risk of death.

Conclusions

Between 4% and 17% of patients with CKD G3–5 develop chronic hyperkalaemia. In general, hyperkalaemia predicted MACE and death; however, the lack of effect of current potassium on MACE when adjusted for the previous pattern, and the stronger effects on death than on MACE, lead us to question whether hyperkalaemia is causal in these relationships.

Stopping mineralocorticoid receptor antagonists after hyperkalaemia: trial emulation in data from routine care

AIMS

Whether to continue or stop mineralocorticoid receptor antagonists (MRA) after an episode of hyperkalaemia is a challenge in clinical practice. While stopping MRA may prevent recurrent hyperkalaemias, it deprives patients of their cardioprotection. We here assessed the association between stopping vs. continuing MRA therapy after hyperkalaemia and the subsequent risks of adverse health events.

METHODS AND RESULTS

Observational study from the Stockholm CREAtinine Measurements (SCREAM) project 2006-2018. We identified patients initiating MRA and surviving a first-detected episode of hyperkalaemia (plasma potassium >5.0 mmol/L). Using target trial emulation methods, we assessed the association between stopping vs. continuing MRA within 6 months after hyperkalaemia and subsequent outcomes. The primary outcome was the composite of hospital admission with heart failure, stroke, myocardial infarction, or death. The secondary outcome was occurrence of another hyperkalaemia event. Among 39 518 patients initiating MRA, we identified 7366 who developed hyperkalaemia. Median age was 76 years, 45% were women and 69% had a history of heart failure. Following hyperkalaemia, 2222 (30%) discontinued treatment. Compared with continuing MRA, stopping therapy was associated with a lower 2-year risk of recurrent hyperkalaemia [hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.72-0.79], but a higher risk of the primary outcome (HR 1.10, 95% CI 1.06-1.14). Similar results were observed in patients with heart failure, after censoring when treatment decision was changed, and across pre-specified subgroups.

CONCLUSIONS

Stopping MRA after an episode of hyperkalaemia was associated with reduced risk for recurrent hyperkalaemia, but higher risk of death or cardiovascular events. Recurrent hyperkalaemia was common in either strategy.

Kidney Function, Kidney Function Decline, and the Risk of Dementia in Older Adults: A Registry-Based Study

OBJECTIVE

Community-based reports regarding the association between the estimated glomerular filtration rate (eGFR) and dementia risk show conflicting results. The aim of this study is to investigate the links among kidney function, kidney function decline, and dementia incidence.

METHODS

We analyzed the association of eGFR with the risk of dementia (defined as a new dementia diagnosis or initiation of dementia treatments) among 329,822 residents of Stockholm who accessed health care during 2006 to 2011, were ≥65 years of age, had no history of dementia, or underwent kidney replacement therapy. We also estimated the rate of eGFR decline among 205,622 residents with repeated eGFR measurements during the first year of observation and investigated its association with subsequent dementia risk.

RESULTS

We detected 18,983 cases of dementia (5.8% of participants) over a median follow-up of 5 years. Dementia incidence rates were progressively higher with lower eGFR: from 6.56/1,000 person-years in those with eGFR of 90 to 104 mL/min to 30.28/1,000 person-years in those with eGFR <30 mL/min. After multivariable adjustment, lower eGFR was associated with a higher dementia risk (hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.54-1.91 in eGFR 30-59 mL/min; HR 2.62, 95% CI 1.91-3.58 in eGFR <30 mL/min) compared with eGFR of 90 to 104 mL/min. A steeper decline in eGFR (decline >2 mL/min/1.73 m2/y) within 1 year was associated with higher dementia risk. Risk magnitudes were stronger for vascular dementia than for Alzheimer dementia. As many as 10% (95% CI 6%-14%) of dementia cases could be attributed to eGFR <60 mL/min/1.73 m2, a proportion higher than that attributed to other dementia risk factors such as cardiovascular disease and diabetes.

CONCLUSIONS

Both lower kidney function and steeper kidney function decline are associated with the development of dementia.

Validation of risk scores for ischaemic stroke in atrial fibrillation across the spectrum of kidney function

Aims 

The increasing prevalence of ischaemic stroke (IS) can partly be explained by the likewise growing number of patients with chronic kidney disease (CKD). Risk scores have been developed to identify high-risk patients, allowing for personalized anticoagulation therapy. However, predictive performance in CKD is unclear. The aim of this study is to validate six commonly used risk scores for IS in atrial fibrillation (AF) patients across the spectrum of kidney function.

Methods and results 

Overall, 36 004 subjects with newly diagnosed AF from SCREAM (Stockholm CREAtinine Measurements), a healthcare utilization cohort of Stockholm residents, were included. Predictive performance of the AFI, CHADS₂, Modified CHADS₂, CHA₂DS₂-VASc, ATRIA, and GARFIELD-AF risk scores was evaluated across three strata of kidney function: normal kidney function [estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m²], mild CKD (eGFR 30–60 mL/min/1.73 m²), and advanced CKD (eGFR <30 mL/min/1.73 m²). Predictive performance was assessed by discrimination and calibration. During 1.9 years, 3069 (8.5%) patients suffered an IS. Discrimination was dependent on eGFR: the median c-statistic in normal eGFR was 0.75 (range 0.68–0.78), but decreased to 0.68 (0.58–0.73) and 0.68 (0.55–0.74) for mild and advanced CKD, respectively. Calibration was reasonable and largely independent of eGFR. The Modified CHADS₂ score showed good performance across kidney function strata, both for discrimination [c-statistic: 0.78 (95% confidence interval 0.77–0.79), 0.73 (0.71–0.74) and 0.74 (0.69–0.79), respectively] and calibration.

Conclusion 

In the most clinically relevant stages of CKD, predictive performance of the majority of risk scores was poor, increasing the risk of misclassification and thus of over- or undertreatment. The Modified CHADS₂ score performed good and consistently across all kidney function strata, and should therefore be preferred for risk estimation in AF patients.

Methods and rationale of the DISCOVER CKD global observational study

Background

Real-world data for patients with chronic kidney disease (CKD), specifically pertaining to clinical management, metabolic control, treatment patterns, quality of life (QoL) and dietary patterns, are limited. Understanding these gaps using real-world, routine care data will improve our understanding of the challenges and consequences faced by patients with CKD, and will facilitate the long-term goal of improving their management and prognosis.

Methods

DISCOVER CKD follows an enriched hybrid study design, with both retrospective and prospective patient cohorts, integrating primary and secondary data from patients with CKD from China, Italy, Japan, Sweden, the UK and the USA. Data will be prospectively captured over a 3-year period from >1000 patients with CKD who will be followed up for at least 1 year via electronic case report form entry during routine clinical visits and also via a mobile/tablet-based application, enabling the capture of patient-reported outcomes (PROs). In-depth interviews will be conducted in a subset of ∼100 patients. Separately, secondary data will be retrospectively captured from >2 000 000 patients with CKD, extracted from existing datasets and registries.

Results

The DISCOVER CKD program captures and will report on patient demographics, biomarker and laboratory measurements, medical histories, clinical outcomes, healthcare resource utilization, medications, dietary patterns, physical activity and PROs (including QoL and qualitative interviews).

Conclusions

The DISCOVER CKD program will provide contemporary real-world insight to inform clinical practice and improve our understanding of the epidemiology and clinical and economic burden of CKD, as well as determinants of clinical outcomes and PROs from a range of geographical regions in a real-world CKD setting.

Stress Related Disorders and the Risk of Kidney Disease

INTRODUCTION

Stress related disorders (SRDs, i.e., psychiatric disorders induced by significant life stressors) increase vulnerability to health problems. Whether SRDs associate with risk of acute kidney injury (AKI) and chronic kidney disease (CKD) is unknown.

METHODS

A population-matched cohort study in Sweden included 30,998 patients receiving a SRDs diagnosis and 116,677 unexposed patients matched by age, sex and estimated glomerular filtration rates (eGFR). The primary outcome was CKD progression, defined as a sustained relative decline in eGFR of more than 40% or commencement of kidney replacement therapy. The secondary outcome was AKI, defined by death or hospitalization attributed to AKI or rapid creatinine changes (increase ≥ 0.3 mg/d over 48 hours or 1.5x over 7 days). Cox models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

During a medium follow-up of 3.2 years, compared to the unexposed, patients with SRDs (median age 45 years, 71% women), were at increased risk of CKD progression (HR 1.23, 95% CI 1.10-1.37) and AKI (HR 1.22, 95% CI 1.04-1.42). While the HR of CKD progression remained similarly elevated during the entire follow-up period, the association with AKI was only observed during the first year after SRDs diagnosis. Results were consistent in stratified analyses, when only considering AKI-hospitalizations/death, and when disregarding eGFR measurements close to index date.

CONCLUSIONS

A diagnosis of SRDs is associated with subsequent risk of AKI and CKD progression. While studies should confirm this observation and characterize underlying mechanisms, close monitoring of kidney function following SRDs diagnosis may be indicated.

Arteriovenous access placement and renal function decline

BACKGROUND

There is controversial evidence on whether arteriovenous access (AVA) placement may protect renal function and hence should be considered in the timing of access placement. This study aimed to investigate the association between AVA placement and estimated glomerular filtration rate (eGFR) decline as compared with the placement of a peritoneal dialysis catheter (PDC) at a similar time point.

METHODS

We studied a cohort of 744 pre-dialysis patients in Stockholm, Sweden, who underwent surgery for AVA or PDC between 2006 and 2012. Data on comorbidity, medication and laboratory measures were collected 100 days before and after surgery. Patients were followed until dialysis start, death or 100 days, whichever came first. The primary outcome was difference in eGFR decline after AVA surgery compared with PDC. Decline in eGFR was estimated through linear mixed models with random intercept and slope, before and after surgery.

RESULTS

There were 435 AVA and 309 PDC patients. The AVA patients had higher eGFR (8.1 mL/min/1.73 m2 versus 7.0 mL/min/1.73 m2) and less rapid eGFR decline before surgery (-5.6 mL/min/1.73 m2/year compared with -6.7 mL/min/1.73 m2/year for PDC). We found no difference in eGFR decline after surgery in AVA patients compared with PDC patients [AVA progressed 0.26 (95% confidence interval -0.88 to 0.35) mL/min/1.73 m2/year faster after surgery compared with PDC].

CONCLUSIONS

There was no significant difference in eGFR decline after placement of an AVA compared with a PDC. Both forms of access were associated with reduced eGFR decline in our population. The need for dialysis remains the main determinant for timing of access surgery.

CKD Progression and Mortality Among Men and Women: A Nationwide Study in Sweden

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD) is a global health problem with increasing prevalence. Several sex-specific differences have been reported for disease progression and mortality. Selection and survival bias might have influenced the results of previous cohort studies. The objective of this study was to investigate sex-specific differences of CKD progression and mortality among patients with CKD not receiving maintenance dialysis.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Adult patients with incident CKD glomerular filtration rate categories 3b to 5 (G3b-G5) identified between 2010 and 2018 within the nationwide Swedish Renal Registry-CKD (SRR-CKD).

EXPOSURE

Sex.

OUTCOMES

Time to CKD progression (defined as a change of at least 1 CKD stage or initiation of kidney replacement therapy [KRT]) or death. Repeated assessments of estimated glomerular filtration rate (eGFR).

ANALYTICAL APPROACH

CKD progression and mortality before KRT were assessed by the cumulative incidence function methods and Fine and Gray models, with death handled as a competing event. Sex differences in eGFR slope were estimated using mixed effects linear regression models.

RESULTS

7,388 patients with incident CKD G3b, 18,282 with incident CKD G4, and 9,410 with incident CKD G5 were identified. Overall, 19.6 (95% CI, 19.2-20.0) patients per 100 patient-years progressed, and 10.1 (95% CI, 9.9-10.3) patients per 100 person-years died. Women had a lower risk of CKD progression (subhazard ratio [SHR], 0.88 [95% CI, 0.85-0.92]), and a lower all-cause (SHR, 0.90 [95% CI, 0.85-0.94]) and cardiovascular (SHR, 0.83 [95% CI, 0.76-0.90]) mortality risk. Risk factors related to a steeper decline in eGFR included age, sex, albuminuria, and type of primary kidney disease.

LIMITATIONS

Incomplete data for outpatient visits and laboratory measurements and regional differences in reporting.

CONCLUSIONS

Compared to women, men had a higher rate of all-cause and cardiovascular mortality, an increased risk of CKD progression, and a steeper decline in eGFR.

Glycemic Control and the Risk of Acute Kidney Injury in Patients With Type 2 Diabetes and Chronic Kidney Disease: Parallel Population-Based Cohort Studies in U.S. and Swedish Routine Care

OBJECTIVE

Patients with diabetes and chronic kidney disease (CKD) have increased susceptibility to acute kidney injury (AKI), but mechanisms are unclear. We investigated the association of glycemic control with risk of AKI.

RESEARCH DESIGN AND METHODS

In two observational cohorts of U.S. (Geisinger Health System, Danville, PA) and Swedish (Stockholm CREAtinine Measurements [SCREAM] project, Stockholm, Sweden) adults with type 2 diabetes and confirmed CKD stages G3-G5 undergoing routine care, we evaluated associations between baseline and time-varying hemoglobin A_1c (HbA_1c) with the incident AKI (defined as increase in creatinine ≥0.3 mg/dL over 48 h or 1.5 times creatinine over 7 days).

RESULTS

In the U.S. cohort, there were 22,877 patients (55% women) with a median age of 72 years and estimated glomerular filtration rate (eGFR) 52 mL/min/1.73 m². In the Swedish cohort, there were 12,157 patients (50% women) with a median age of 77 years and eGFR 51 mL/min/1.73 m². During 3.1 and 2.3 years of follow-up, 7,060 and 2,619 AKI events were recorded in the U.S. and Swedish cohorts, respectively. The adjusted association between baseline HbA_1c and AKI was similar in both cohorts. Compared with baseline HbA_1c 6-6.9% (42-52 mmol/mol), the hazard ratio for AKI in patients with HbA_1c >9% (75 mmol/mol) was 1.29 (95% CI 1.18-1.41) in Geisinger and 1.33 (95% CI 1.13-1.57) in the Swedish cohort. Results were consistent in stratified analysis, when using death as competing risk, and when using time-varying HbA_1c.

CONCLUSIONS

Higher HbA_1c was associated with AKI in adults with type 2 diabetes and CKD, suggesting that improving glycemic control may reduce the risk of AKI.

Short- and long-term outcomes after incident pneumonia in adults with chronic kidney disease: a time-dependent analysis from the Stockholm CREAtinine Measurement project

BACKGROUND

Little is known about the health sequelae of pneumonia in persons with chronic kidney disease (CKD).

METHODS

We studied adults with CKD in Stockholm during 2006-11, who not previously been diagnosed with lower respiratory tract infections. We used multivariable-adjusted Cox regression with pneumonia as a time-varying exposure to estimate hazard ratios (HRs) [95% confidence intervals (CIs)] for the events of death, major adverse cardiovascular events (MACEs), acute kidney injury (AKI), CKD progression or hospitalization for urinary tract infections (UTIs)/sepsis. Cataract and knee/joint replacement served as negative control outcomes.

RESULTS

We identified 71 931 adults (mean age 79 years, 59% women), of whom 8379 (12%) were diagnosed with pneumonia during follow-up; incident pneumonia was associated with 10 times higher adjusted mortality risk during the first 90 days [HR = 10.0, 95% confidence interval (CI) 9.5-10.5] and double the mortality beyond 90 days from pneumonia diagnosis (HR = 2.0; 95% CI 1.9-2.1). Incident pneumonia was similarly associated with higher adjusted risk of MACE (<90 days: HR = 12.6; 95% CI 12.0-13.3; ≥90 days: HR = 1.5; 95% CI 1.4-1.6). The adjusted risk of CKD progression and UTI/sepsis hospitalization was highest within 90 days from pneumonia but remained elevated thereafter. For AKI, the association with incident pneumonia was only seen within 90 days. Neither cataract nor knee/joint replacement was related to pneumonia.

CONCLUSIONS

Incident pneumonia was associated with increased risks of MACE, CKD progression, severe UTI/sepsis and death, with risks highest soon after pneumonia diagnosis but extending beyond 90 days. Our findings highlight the susceptibility for adverse outcomes of CKD patients following pneumonia diagnosis, and may inform clinical decisions regarding vaccination strategies.

Fractures and their sequelae in non-dialysis-dependent chronic kidney disease: the Stockholm CREAtinine Measurement project

Introduction

People undergoing maintenance dialysis are at high risk for fractures, but less is known about fracture incidence and associated outcomes in earlier stages of chronic kidney disease (CKD).

Methods

We conducted an observational analysis from the Stockholm Creatinine Measurement project, a Swedish health care utilization cohort during 2006–11. We identified all adults with confirmed CKD Stages 3–5 and no documented history of fractures and extracted information on comorbid history, ongoing medication, cardiovascular events and death. We studied incidence rates of fractures (overall and by location), with the estimated glomerular filtration rate (eGFR) as time-dependent exposure. We then studied hazard ratios [HRs and 95% confidence intervals (CIs)] for the events of death and major adverse cardiac events (MACE) using Cox regression with fracture as time-varying exposure.

Results

We identified 68 764 individuals with confirmed CKD (mean age 79 years, 56% women). During a median follow-up of 2.7 years, 9219 fractures occurred, of which 3105 were hip fractures. A more severe CKD stage was associated with a higher risk of fractures, particularly hip fractures: compared with CKD Stage 3a, the adjusted HR was 1.10 (95% CI 1.02–1.19), 1.32 (1.17–1.49) and 2.47 (1.94–3.15) for CKD Stage 3b, 4 and 5, respectively. Spline curves suggested a linear association with fracture risk with an eGFR <30 mL/min/1.73 m². Compared with non-fracture periods, incident fracture was associated with a 4-fold increased mortality within 90 days [HR 4.21 (95% CI 3.95–4.49)]. The risk remained elevated beyond 90 days [HR 1.47 (95% CI 1.40–1.54)] and was stronger after hip fractures. Post-fracture MACE risk was also highest in the first 90 days [HR 4.02 (95% CI 3.73–4.33)], particularly after hip fractures, and persisted beyond 90 days [HR 1.20 (95% CI 1.10–1.30)].

Conclusion

Our findings highlight the commonness of fractures and the increased risk for subsequent adverse outcomes in CKD patients. These results may inform clinical decisions regarding post-fracture clinical surveillance and fracture prevention strategies.

Creatinine and C-reactive protein in amyotrophic lateral sclerosis, multiple sclerosis and Parkinson's disease

Serum creatinine and C-reactive protein have been proposed as potential biomarkers for neurodegenerative diseases, including amyotrophic lateral sclerosis, multiple sclerosis and Parkinson’s disease. However, longitudinal studies investigating temporal patterns of these biomarkers, including the phase before diagnosis, are rare. We performed a case–control study including all newly diagnosed patients with amyotrophic lateral sclerosis (N = 525), multiple sclerosis (N = 1815) or Parkinson’s disease (N = 3797) during 2006–2013 in Stockholm, Sweden, who participated in the Stockholm CREAtinine Measurements (SCREAM) project. For each case, we randomly selected up to five controls from SCREAM that were individually matched to the case by age, sex and county of residence (N = 2625 for amyotrophic lateral sclerosis, N = 9063 for multiple sclerosis and 18 960 for Parkinson’s disease). We collected for both the cases and the controls testing results of serum creatinine and C-reactive protein performed by healthcare providers in Stockholm during the study period. Median levels of creatinine and C-reactive protein were visualized using locally weighted smoothing curves among cases and controls. A linear mixed model was also applied to explore temporal changes within an individual. Compared to controls, patients with amyotrophic lateral sclerosis had lower levels of creatinine from 2 years before diagnosis onwards. In contrast, patients with amyotrophic lateral sclerosis had lower levels of C-reactive protein before diagnosis but higher levels after diagnosis, compared to controls. Focusing the 2 years before to 2 years after diagnosis, patients with amyotrophic lateral sclerosis displayed statistically significantly decreasing level of creatinine from 1 year before diagnosis until 2 years after diagnosis, whereas increasing level of C-reactive protein from diagnosis until 2 years after diagnosis. There were no similar patterns noted among patients with multiple sclerosis or Parkinson’s disease, or the controls of the three patient groups. Patients with amyotrophic lateral sclerosis display distinct temporal patterns of creatinine and C-reactive protein before and after diagnosis, compared to amyotrophic lateral sclerosis-free controls or patients with multiple sclerosis and Parkinson’s disease.

Association between reduced kidney function and incident hypoglycaemia in people with diabetes: The Stockholm Creatinine Measurements (SCREAM) project

AIM

To evaluate possible associations between estimated glomerular filtration rate (eGFR) and hypoglycaemia in adults with diabetes.

METHODS

We conducted an observational study in adults with diabetes from the Stockholm Creatinine Measurement (SCREAM) project, a Swedish healthcare utilization cohort during 2007 to 2011. We evaluated diagnoses and outpatient glucose tests for incidence rate ratios (IRRs) of hypoglycaemia (overall and by severity) in outpatient care by eGFR strata using zero-inflated negative binomial regression. We identified clinical predictors through ordinal logistic regression and assessed 7-day and 30-day mortality from hypoglycaemia in relation to eGFR with Cox proportional hazard models.

RESULTS

We identified 29 434 people with diabetes (13% with type 1 diabetes). Their mean age was 66 years, 43% were women and the median eGFR was 80 mL/min/1.73 m² . During 2 years of follow-up, 1812 patients (6.2%) had hypoglycaemia registered at least once. The risk of hypoglycaemia increased linearly with lower eGFR, with an IRR of 1.2 (95% confidence interval [CI] 1.0-1.4) for eGFR 60-89 mL/min/1.73 m² and 5.8 (95% CI 3.8-9.0) for eGFR <15 mL/min/1.73 m² compared to eGFR 90 to 104 mL/min/1.73 m² . This trend was observed for both mild and severe hypoglycaemia. Both 7-day and 30-day post-hypoglycaemia mortality increased with lower eGFR, peaking in those with eGFR <15 mL/min/1.73 m² (hazard ratio 21.2, 95% CI 5.1-87.9) as compared to those with eGFR 90 to 104 mL/min/1.73 m² . Lower eGFR categories, type 1 diabetes, previous hypoglycaemia, liver disease, presence of diabetic complications and use of insulin and sulphonylureas increased the odds of hypoglycaemia.

CONCLUSION

In this large, observational study, low eGFR was strongly associated with the occurrence, severity and fatality of hypoglycaemia in people with diabetes.

Stopping renin-angiotensin system blockers after acute kidney injury and risk of adverse outcomes: parallel population-based cohort studies in English and Swedish routine care

BACKGROUND

The safety of restarting angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) after acute kidney injury (AKI) is unclear. There is concern that previous users do not restart ACEI/ARB despite ongoing indications. We sought to determine the risk of adverse events after an episode of AKI, comparing prior ACEI/ARB users who stop treatment to those who continue.

METHODS

We conducted two parallel cohort studies in English and Swedish primary and secondary care, 2006-2016. We used multivariable Cox regression to estimate hazard ratios (HR) for hospital admission with heart failure (primary analysis), AKI, stroke, or death within 2 years after hospital discharge following a first AKI episode. We compared risks of admission between people who stopped ACEI/ARB treatment to those who were prescribed ACEI/ARB within 30 days of AKI discharge. We undertook sensitivity analyses, including propensity score-matched samples, to explore the robustness of our results.

RESULTS

In England, we included 7303 people with AKI hospitalisation following recent ACEI/ARB therapy for the primary analysis. Four thousand three (55%) were classified as stopping ACEI/ARB based on no prescription within 30 days of discharge. In Sweden, we included 1790 people, of whom 1235 (69%) stopped treatment. In England, no differences were seen in subsequent risk of heart failure (HR 1.10; 95% confidence intervals (CI) 0.93-1.30), AKI (HR 0.90; 95% CI 0.77-1.05), or stroke (HR 0.99; 95% CI 0.71-1.38), but there was an increased risk of death (HR 1.27; 95% CI 1.15-1.41) in those who stopped ACEI/ARB compared to those who continued. Results were similar in Sweden: no differences were seen in risk of heart failure (HR 0.91; 95% CI 0.73-1.13) or AKI (HR 0.81; 95% CI 0.54-1.21). However, no increased risk of death was seen (HR 0.94; 95% CI 0.78-1.13) and stroke was less common in people who stopped ACEI/ARB (HR 0.56; 95% CI 0.34-0.93). Results were similar across all sensitivity analyses.

CONCLUSIONS

Previous ACEI/ARB users who continued treatment after an episode of AKI did not have an increased risk of heart failure or subsequent AKI compared to those who stopped the drugs.

Albuminuria as a Predictor of Cardiovascular Outcomes in Patients With Acute Myocardial Infarction

Background In patients with myocardial infarction ( MI ), reduced kidney function is recognized as an important predictor of poor prognosis, but the impact of albuminuria, a representative measure of kidney damage, has not been extensively evaluated. Methods and Results In the SCREAM (Stockholm Creatinine Measurements) project (2006-2012), we identified 2469 patients with incident MI with dipstick proteinuria measured within a year before MI (427 patients also had urine albumin to creatinine ratio [ ACR ] measured concurrently) and obtained estimates for ACR with multiple imputation in participants with data solely on dipstick proteinuria. We quantified the association of ACR with the post- MI composite and individual outcomes of all-cause mortality, cardiovascular mortality, recurrent MI , ischemic stroke, or heart failure using Cox models and then evaluated the improvement in C statistic. During a median follow-up of 1.0 year after MI , 1607 participants (65.1%) developed the post- MI composite outcome. Higher ACR levels were independently associated with all outcomes except for ischemic stroke. Per 8-fold higher ACR (eg, 40 versus 5 mg/g), the hazard ratio of composite outcome was 1.21 (95% CI , 1.08-1.35). The addition of the ACR improved the C statistic of the post- MI composite by 0.040 (95% CI, 0.030-0.051). Largely similar results were obtained regardless of diabetic status and when ACR or dipstick was separately analyzed without imputation. Conclusions In patients with MI , albuminuria was a potent predictor of subsequent outcomes, suggesting the importance of paying attention to the information on albuminuria, in addition to kidney function, in this high-risk population.

Existing Data Sources in Clinical Epidemiology: Laboratory Information System Databases in Denmark

Routine biomarker results from hospital laboratory information systems, covering hospitals and general practitioners, in Denmark are available to researchers through access to the regional Clinical Laboratory Information System Research Database at Aarhus University and the nationwide Register of Laboratory Results for Research. This review describes these two data sources. The laboratory databases have different geographical and temporal coverage. They both include individual-level biomarker results that are electronically transferred from laboratory information systems. The biomarker results can be linked to all other Danish registries at the individual level, using the unique identifier, the CPR number. The databases include variables such as the CPR number, date and time (hour and minute) of sampling, NPU code, and name of the biomarker, identification code for the laboratory and the requisitioner, the test result with the corresponding unit, and the lower and upper reference limits. Access to the two databases differs since they are hosted by two different institutions. Data cannot be transferred outside Denmark, and direct access is provided only to Danish institutions. It is concluded that access to data on routine biomarkers expands the detailed biological and clinical information available on patients in the Danish healthcare system. The full potential is enabled through linkage to other Danish healthcare registries.

Bisphosphonate utilization across the spectrum of eGFR

Bisphosphonates are the most common treatment for osteoporosis but there are concerns regarding its use in CKD. We evaluated the frequency of BSP by eGFR categories among patients with osteoporosis from two healthcare systems. Our results show that 56% of patients were treated, with reduced odds in those with lower eGFR.

INTRODUCTION

Osteoporosis is common in patients with chronic kidney disease (CKD). Bisphosphonates (BSP) are the most common treatment but there are concerns regarding its efficacy and toxicity in CKD. We evaluated the frequency of BSP use by level of estimated glomerular filtration rate (eGFR) in patients with osteoporosis.

METHODS

We assessed BSP use in patients with incident osteoporosis from the SCREAM-Cohort, Stockholm-Sweden, and Geisinger Healthcare, PA, USA. Osteoporosis was defined as the first encountered ICD diagnosis, and BSP use was defined as the dispensation or prescription of any BSP from 6 months prior to 3 years after the diagnosis. Multinomial logistic regression was used to account for the competing risk of death.

RESULTS

A total of 15,719 women and 3011 men in SCREAM and 17,325 women and 3568 men in Geisinger with incident osteoporosis were included. Overall, 56% of individuals used BSP in both studies, with a higher proportion in women. After adjustments, the odds of BSP was lower across lower eGFR in SCREAM, ranging from 0.90 (0.81-0.99) for eGFR 75-89 mL/min/1.73m² to 0.56 (0.46-0.68) for eGFR 30-44 mL/min/1.73m² in women and from 0.72 (0.54-0.97) for eGFR of 60-74 to 0.42 (0.25-0.70) for eGFR 30-44 mL/min/1.73m² in men. In Geisinger, odds were lower for eGFR < 30 mL/min/1.73m² in both sexes and the frequency of BSP use dropped over time.

CONCLUSION

In the two healthcare systems, approximately half of the people diagnosed with osteoporosis received BSP. Practices of prescription in relation to eGFR varied, but those with lower eGFR were less likely to receive BSP.

Sex-specific analysis of haemodialysis prevalence, practices and mortality over time: the Austrian Dialysis Registry from 1965 to 2014

BACKGROUND

Despite a higher prevalence of chronic kidney disease among women, more men than women start renal replacement therapy (RRT). We hypothesized that gender differences in health care access exist and therefore aimed at determining whether characteristics and outcomes of haemodialysis patients over time differ by sex.

METHODS

We studied all 28 323 adults who began haemodialysis during 1965-2014 in the Austrian Dialysis Registry, analysing trends in patient characteristics by sex and decade with mortality (via Cox regression), which was compared with the mortality of the Austrian general population.

RESULTS

More men than women started haemodialysis (60.1% men versus 39.9% women overall), with minor differences among decades and age groups. The male:female mortality rate ratio in the general population ranged from 1.2 to 2.4 for age groups >18 years and in haemodialysis patients ranged from 0.80 to 1.3 (closer to 1 than in the general population, but consistently >1 in Decades 3-5). In recent decades, diabetes and hypertension replaced glomerulonephritis as the primary cause of end-stage renal disease in both men and women. Interaction analyses showed the mortality risk associated with haemodialysis access (only recorded in Decade 5) was significantly lower for men than for women.

CONCLUSIONS

The male:female mortality rate ratio and the proportion of women starting haemodialysis were remarkably stable, which does not support the hypothesis of gender differences in health care/haemodialysis access or could imply that such differences might have persisted over decades. Future research should expand to other countries and other forms of RRT.

Plasma potassium ranges associated with mortality across stages of chronic kidney disease: the Stockholm CREAtinine Measurements (SCREAM) project

Background

Small-scale studies suggest that hyperkalaemia is a less threatening condition in chronic kidney disease (CKD), arguing adaptation/tolerance to potassium (K⁺) retention. This study formally evaluates this hypothesis by estimating the distribution of plasma K⁺ and its association with mortality across CKD stages.

Methods

This observational study included all patients undergoing plasma K⁺ testing in Stockholm during 2006–11. We randomly selected one K⁺ measurement per patient and constructed a cross-sectional cohort with mortality follow-up. Covariates included demographics, comorbidities, medications and estimated glomerular filtration rate (eGFR). We estimated K⁺ distribution and defined K⁺ ranges associated with 90-, 180- and 365-day mortality.

Results

Included were 831 760 participants, of which 70 403 (8.5%) had CKD G3 (eGFR <60–30 mL/min) and 8594 (1.1%) had CKD G4–G5 (eGFR <30 mL/min). About 66 317 deaths occurred within a year. Adjusted plasma K⁺ increased across worse CKD stages: from median 3.98 (95% confidence interval 3.49–4.59) for eGFR >90 to 4.43 (3.22–5.65) mmol/L for eGFR ≤15 mL/min/1.73 m². The association between K⁺ and mortality was U-shaped, but it flattened at lower eGFR strata and shifted upwards. For instance, the range where the 90-day mortality risk increased by no more than 100% was 3.45–4.94 mmol/L in eGFR >60 mL/min, but was 3.36–5.18  in G3 and 3.26–5.53 mmol/L in G4–G5. In conclusion, CKD stage modifies K⁺ distribution and the ranges that predict mortality in the community.

Conclusion

Although this study supports the view that hyperkalaemia is better tolerated with worse CKD, it challenges the current use of a single optimal K⁺ range for all patients.

Mixed-effects models for health care longitudinal data with an informative visiting process: A Monte Carlo simulation study

Electronic health records are being increasingly used in medical research to answer more relevant and detailed clinical questions; however, they pose new and significant methodological challenges. For instance, observation times are likely correlated with the underlying disease severity: Patients with worse conditions utilise health care more and may have worse biomarker values recorded. Traditional methods for analysing longitudinal data assume independence between observation times and disease severity; yet, with health care data, such assumptions unlikely hold. Through Monte Carlo simulation, we compare different analytical approaches proposed to account for an informative visiting process to assess whether they lead to unbiased results. Furthermore, we formalise a joint model for the observation process and the longitudinal outcome within an extended joint modelling framework. We illustrate our results using data from a pragmatic trial on enhanced care for individuals with chronic kidney disease, and we introduce user-friendly software that can be used to fit the joint model for the observation process and a longitudinal outcome.

Kidney Dysfunction and the Risk of Developing Aortic Stenosis

BACKGROUND

Chronic kidney disease (CKD) and aortic stenosis (AS) share many risk factors.

OBJECTIVES

This study sought to evaluate whether kidney dysfunction is associated with the development of AS in the community.

METHODS

The study included 1,121,875 Stockholm citizens without a prior diagnosis of AS from the SCREAM (Stockholm CREAtinine Measurements) project. Estimated glomerular filtration rate (eGFR) (ml/min/1.73 m²) was calculated from serum creatinine. AS incidence during follow-up was ascertained by clinical diagnostic codes. The association between eGFR and AS incidence was estimated with multivariable Cox proportional hazards models. Sensitivity analyses included analysis of possible reverse causation bias by excluding the first 6 months to 2 years after enrollment and excluding individuals with comorbid heart failure.

RESULTS

The median age was 50 years (interquartile range [IQR]: 36 to 64 years), and 54% of participants were women. Median eGFR was 96 ml/min/1.73 m² (IQR: 82 to 109 ml/min/1.73 m²), and 66,949 (6.0%) participants had CKD (eGFR <60 ml/min/1.73 m²). During a median follow-up of 5.1 years (IQR: 3.3 to 6.1 years), 5,858 (0.5%) individuals developed AS (incidence rate [IR] 1.13/1,000 person-years). Compared with eGFR >90 (IR 0.34/1,000 person-years), lower eGFR strata were associated with higher hazards of AS: eGFR 60 to 90 ml/min/1.73 m²; IR: 1.88; hazard ratio (HR): 1.14; 95% confidence interval (CI): 1.05 to 1.25; eGFR 45 to 59 ml/min/1.73 m²; IR: 4.61; HR: 1.17; 95% CI: 1.05 to 1.30; eGFR 30 to 44 ml/min/1.73 m²; IR: 6.62; HR: 1.22; 95% CI: 1.07 to 1.39; and eGFR 30 ml/min/1.73 m²; IR: 8.27; HR: 1.56; 95% CI: 1.29 to 1.87. Sensitivity analysis attenuated only slightly the magnitude of the association; individuals with eGFR ≤44 ml/min/1.73 m² remained at an approximate 20% risk of AS both when excluding events within the 2 years after baseline (HR: 1.22; 95% CI: 1.06 to 1.42) and when excluding participants with heart failure (HR: 1.20; 95% CI: 1.03 to 1.39).

CONCLUSIONS

CKD, even in moderate to severe stages, is associated with an increased risk of AS.

Incidence of, Associations With and Prognostic Impact of Worsening Renal Function in Heart Failure With Different Ejection Fraction Categories

There are no studies of long-term worsening renal function (WRF) in heart failure (HF) with different ejection fraction (EF) groups. The aim was to compare incidence of, associations with and prognostic impact of WRF in HF with preserved (HFpEF), mid-range (HFmrEF), and reduced EF (HFrEF). The Swedish Heart Failure Registry (SwedeHF) was merged with the Stockholm Creatinine Measurement (SCREAM) registry 2006 to 2010. The associations between EF and WRF (≥25% decrease in eGFR) and the associations between WRF25-49% and WRF≥50% within year one and subsequent all-cause mortality were all assessed with multiadjusted Cox regression. Of 7,154 patients, 41.6% of HFpEF versus 34.5% and 35.4% of HFmrEF and HFrEF patients developed WRF≥25% during year one. The WRF risk was higher in HFpEF (reference) than in HFmrEF, hazard ratio (95% confidence interval) 0.890 (0.794 to 0.997) and HFrEF 0.870 (0.784 to 0.965). WRF within year one was strongly associated with subsequent long-term mortality in all EF groups, yielding adjusted HRs with WRF25-49% and WRF≥50%: HFpEF, 1.101 (0.913 to 1.328) and 2.096 (1.652 to 2.659), in HFmrEF 1.654 (1.353 to 2.022) and 2.375 (1.807 to 3.122) and in HFrEF 1.212 (1.060 to 1.386) and 1.694 (1.412 to 2.033). In conclusion, the long-term WRF risk was high in HF and highest in HFpEF. WRF was strongly associated with mortality in all EF groups, although in HFpEF only with the most severe WRF.

High-sensitivity C-reactive protein and the risk of chronic kidney disease progression or acute kidney injury in post-myocardial infarction patients

BACKGROUND

Persistent, low-grade inflammation likely participates in the pathophysiology of both atherosclerosis and kidney disease. Although high-sensitivity C-reactive protein (hsCRP) predicts future cardiovascular risk in patients with chronic kidney disease (CKD), it is unknown whether hsCRP levels predict adverse renal outcomes in patients with cardiovascular disease.

METHODS

We studied all myocardial infarction (MI) survivors undergoing hsCRP testing >30 days after their MI during routine health care in Stockholm, Sweden (2006-2011), with available information on estimated glomerular filtration rate (eGFR). HsCRP tests measured during hospitalization/emergency room visits, followed by antibiotics or indicative of acute illness, were excluded, together with patients with ongoing/recent cancer, chronic infections, or immunosuppression. Inflammation was defined over a 3-month baseline window. Study outcomes were CKD progression (composite of doubling plasma creatinine, renal replacement therapy, or renal death) and acute kidney injury (AKI, acute creatinine peaks according to Kidney Disease: Improving Global Outcomes criteria). Multivariable Cox regression was used to adjust for age, sex, eGFR, hemoglobin, time since MI, comorbidities, undertaken procedures, and medications.

RESULTS

A total of 12,905 patients (62% men, mean age 73 years and 3 years since MI) were included, of whom 35% had an eGFR<60 mL/min/1.73 m². The mean (SD) hsCRP was 3.0 (4.4) mg/L. Baseline hsCRP levels were increasingly higher across lower eGFR categories. During a median follow-up of 3.2 years, 1,019 CKD progressions and 1,481 AKI events were recorded. Patients with hsCRP ≥2 mg/L were at higher risk of both CKD progression (adjusted hazard ratio 1.42; 95% CI 1.21-1.66) and AKI (1.29; 1.13-1.47) compared to those with hsCRP <2 mg/L. This association persisted across single CKD severity stages and after further hsCRP categorization into 4 groups (≤1, 1-3, 3-10, >10 mg/L). Results were robust across subgroups of patients and after exclusion of events occurring during the first 6-12 months.

CONCLUSIONS

In post-MI patients undergoing routine health care, elevated hsCRP was associated with subsequent risk of AKI and progression of CKD, irrespective of baseline kidney function.

Association of Acute Increases in Plasma Creatinine after Renin-Angiotensin Blockade with Subsequent Outcomes

BACKGROUND AND OBJECTIVES

Data from observational and interventional studies provide discordant results regarding the relationship between creatinine increase after renin-angiotensin system inhibition (RASi) and adverse outcomes. We compared health outcomes among patients with different categories of increase in creatinine upon initiation of RASi in a large population-based cohort.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective analysis of the Stockholm CREAtinine Measurements database, which contains complete information on diagnoses, medication dispensation claims, and laboratory test results for all Stockholm citizens accessing health care. Included were 31,951 adults initiating RASi during 2007-2011 with available pre- and postinitiation creatinine monitoring. Multivariable Cox regression was used to compare mortality, cardiovascular and ESKD events among individuals with different ranges of creatinine increases within 2 months after starting treatment.

RESULTS

In a median follow-up of 3.5 years, acute increases in creatinine were associated with mortality (3202 events) in a graded manner: compared with creatinine increases <10%, a 10%-19% increase showed an adjusted hazard ratio (HR) of 1.15 (95% confidence interval [95% CI], 1.05 to 1.27); HR 1.22 (95% CI, 1.07 to 1.40) for 20%-29%; HR 1.55 (95% CI, 1.36 to 1.77) for ≥30%. Similar graded associations were present for heart failure (2275 events, P<0.001) and ESKD (52 events; P<0.001), and, less consistently, myocardial infarction (842 events, P=0.25). Results were robust across subgroups, among continuing users, when patients with decreases in creatinine were excluded from the reference group, and after accounting for death as a competing risk.

CONCLUSIONS

Among real-world monitored adults, increases in creatinine (>10%) after initiation of RASi are associated with worse health outcomes. These results do not address the issue of discontinuation of RASi when plasma creatinine increases but do suggest that patients with increases in creatinine have higher subsequent risk of cardiovascular and kidney outcomes.