Albuminuria predicts kidney events in IgA nephropathy.

BACKGROUND & HYPOTHESIS: KDIGO recommends proteinuria <1 g/d as a treatment target in patients with immunoglobulin A nephropathy (IgAN) because of high-risk of progression to kidney failure. However, long-term kidney outcomes in patients with low-grade proteinuria remain insufficiently studied. METHODS: We enrolled patients with biopsy-proven primary IgAN from the Swedish Renal Registry and analyzed associations between urine albumin-to-creatinine ratio (uACR, in categories < 0.3, ≥0.3-0.5, ≥0.5-1.0, ≥1.0-1.5, ≥1.5-2.0 and ≥ 2.0 g/g) and the occurrence of major adverse kidney events (MAKE, a composite of kidney replacement therapy [KRT] and > 30% decline in eGFR). We also explored the risk of kidney events associated with change in uACR within a year. RESULTS: We included 1269 IgAN patients (74% men, median 53 years, mean eGFR 33 mL/min/1.73m², median uACR 0.7 g/g). Over median follow-up of 5.5 [2.8;9.2] years, 667 MAKE and 517 KRT events occurred, and 528 patients experienced > 30% eGFR decline. Compared with uACR < 0.3 g/g, any higher uACR category was strongly and incrementally associated with the risk of MAKE (adjusted HR ranging from 1.56 [95%CI 1.14-2.14] if uACR 0.3-0.5 g/g to 4.53 [3.36-6.11] if uACR ≥ 2.0 g/g), KRT (HR ranging from 1.39 to 4.65), and eGFR decline > 30% (HR ranging from 1.76 to 3.47). In 785 patients who had repeated uACR measurements within a year, and compared with stable uACR, the risk of kidney events was lower if uACR decreased by 2-fold (HR ranging from 0.47 to 0.49), and higher if uACR increased by 2-fold (HR from 1.18 to 2.56), irrespective of baseline uACR. CONCLUSIONS: There is substantial risk of adverse kidney outcomes among patients with IgAN and uACR between 0.3 and 1.0 g/g, a population currently considered at low-risk of CKD progression. Reduction in uACR is associated with better kidney outcomes, irrespective of baseline uACR.

Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknowns.

The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (CKD) updates the KDIGO 2012 guideline and has been developed with patient partners, clinicians, and researchers around the world, using robust methodology. This update, based on a substantially broader base of evidence than has previously been available, reflects an exciting time in nephrology. New therapies and strategies have been tested in large and diverse populations that help to inform care; however, this guideline is not intended for people receiving dialysis nor those who have a kidney transplant. The document is sensitive to international considerations, CKD across the lifespan, and discusses special considerations in implementation. The scope includes chapters dedicated to the evaluation and risk assessment of people with CKD, management to delay CKD progression and its complications, medication management and drug stewardship in CKD, and optimal models of CKD care. Treatment approaches and actionable guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations which followed the "Grading of Recommendations Assessment, Development, and Evaluation" (GRADE) approach. The limitations of the evidence are discussed. The guideline also provides practice points, which serve to direct clinical care or activities for which a systematic review was not conducted, and it includes useful infographics and describes an important research agenda for the future. It targets a broad audience of people with CKD and their healthcare, while being mindful of implications for policy and payment.

An increase in albuminuria is associated with a higher incidence of malignancies.

Background: A single albuminuria measurement is reported to be an independent predictor of cancer risk. Whether change in albuminuria is also independently associated with cancer is not known. Methods: We included 64 303 subjects of the Stockholm CREAtinine Measurements (SCREAM) project without a history of cancer and with at least two urine albumin-creatinine ratio (ACR) tests up to 2 years apart. Albuminuria changes were quantified by the fold-change in ACR over 2 years, and stratified into the absence of clinically elevated albuminuria (i.e. never), albuminuria that remained constant, and albuminuria that increased or decreased. The primary outcome was overall cancer incidence. Secondary outcomes were site-specific cancer incidences. Results: During a median follow-up of 3.7 (interquartile range 3.6-3.7) years, 5126 subjects developed de novo cancer. After multivariable adjustment including baseline estimated glomerular filtration rate and baseline ACR, subjects with increasing ACR over 2 years had a 19% (hazard ratio 1.19; 95% confidence interval 1.08-1.31) higher risk of overall cancer compared with those who never had clinically elevated ACR. No association with cancer risk was seen in the groups with decreasing or constant ACR. Regarding site-specific cancer risks, subjects with increasing ACR or constant ACR had a higher risk of developing urinary tract and lung cancer. No other associations between 2-year ACR changes and site-specific cancers were found. Conclusions: Increases in albuminuria over a 2-year period are associated with a higher risk of developing overall, urinary tract and lung cancer, independent of baseline kidney function and albuminuria. These data add important weight to the link that exists between albuminuria and cancer incidence.

Clinical impact of the Kidney Failure Risk Equation for vascular access planning.

BACKGROUND: Risk-based thresholds for arteriovenous (AV) access creation has been proposed to aid vascular access planning. We aimed to assess the clinical impact of implementing the kidney failure risk equation (KFRE) for vascular access referral. METHODS: 16,102 nephrology-referred chronic kidney disease (CKD) patients from the Swedish Renal Registry 2008-2018 were included. The KFRE was calculated repeatedly, and the timing was identified for when the KFRE risk exceeded several pre-defined thresholds and/or the estimated glomerular filtration rate <15 ml/min/1.73m2 (eGFR15). To assess the utility of the KFRE/eGFR thresholds, cumulative incidence curves of kidney replacement therapy (KRT) or death, and decision-curve analyses were computed at 6, 12 months, and 2 years. The potential impact of using the different thresholds was illustrated by an example from the Swedish access registry. RESULTS: The 12-month specificity for KRT initiation was highest for KFRE>50% 94.5 (95% Confidence interval [CI] 94.3-94.7), followed by KFRE>40% 90.0 (95% CI 89.7-90.3), while sensitivity was highest for KFRE>30% 79.3 (95% CI 78.2-80.3) and eGFR<15 ml/min/1.73m2 81.2 (95% CI 80.2-82.2). The 2-year positive predictive value was 71.5 (95% CI 70.2-72.8), 61.7 (95% CI 60.4-63.0) and 47.2 (95% CI 46.1-48.3) for KFRE>50%, KFRE>40%, and eGFR<15 respectively. Decision curve analyses suggested the largest net benefit for KFRE>40% over two years and KFRE>50% over 12 months when it is important to avoid the harm of possibly unnecessary surgery. In Sweden, 54% of nephrology-referred patients started hemodialysis in a central venous catheter (CVC) of which only 5% had AV access surgery >6 months before initiation. 60% of the CVC patients exceeded KFRE>40% a median of 0.8 years (interquartile range 0.4-1.5) before KRT initiation. CONCLUSIONS: The utility of using KFRE>40% and KFRE>50% is higher compared to the more traditionally used eGFR threshold <15 ml/min/1.73m2 for vascular access planning.

Association of Low Glomerular Filtration Rate With Adverse Outcomes at Older Age in a Large Population With Routinely Measured Cystatin C.

BACKGROUND: The commonly accepted threshold of glomerular filtration rate (GFR) to define chronic kidney disease (CKD) is less than 60 mL/min/1.73 m2. This threshold is based partly on associations between estimated GFR (eGFR) and the frequency of adverse outcomes. The association is weaker in older adults, which has created disagreement about the appropriateness of the threshold for these persons. In addition, the studies measuring these associations included relatively few outcomes and estimated GFR on the basis of creatinine level (eGFRcr), which may be less accurate in older adults. OBJECTIVE: To evaluate associations in older adults between eGFRcr versus eGFR based on creatinine and cystatin C levels (eGFRcr-cys) and 8 outcomes. DESIGN: Population-based cohort study. SETTING: Stockholm, Sweden, 2010 to 2019. PARTICIPANTS: 82 154 participants aged 65 years or older with outpatient creatinine and cystatin C testing. MEASUREMENTS: Hazard ratios for all-cause mortality, cardiovascular mortality, and kidney failure with replacement therapy (KFRT); incidence rate ratios for recurrent hospitalizations, infection, myocardial infarction or stroke, heart failure, and acute kidney injury. RESULTS: The associations between eGFRcr-cys and outcomes were monotonic, but most associations for eGFRcr were U-shaped. In addition, eGFRcr-cys was more strongly associated with outcomes than eGFRcr. For example, the adjusted hazard ratios for 60 versus 80 mL/min/1.73 m2 for all-cause mortality were 1.2 (95% CI, 1.1 to 1.3) for eGFRcr-cys and 1.0 (CI, 0.9 to 1.0) for eGFRcr, and for KFRT they were 2.6 (CI, 1.2 to 5.8) and 1.4 (CI, 0.7 to 2.8), respectively. Similar findings were observed in subgroups, including those with a urinary albumin-creatinine ratio below 30 mg/g. LIMITATION: No GFR measurements. CONCLUSION: Compared with low eGFRcr in older patients, low eGFRcr-cys was more strongly associated with adverse outcomes and the associations were more uniform. PRIMARY FUNDING SOURCE: Swedish Research Council, National Institutes of Health, and Dutch Kidney Foundation.

Oral anticoagulant treatment and risk of kidney disease-a nationwide, population-based cohort study.

Background: Direct oral anticoagulants (DOACs) are recommended as first-line treatment of atrial fibrillation. Whether DOAC use is associated with lower risks of kidney complications compared with vitamin K antagonists (VKAs) remains unclear. We examined this association in a nationwide, population-based cohort study. Methods: We conducted a cohort study including patients initiating oral anticoagulant treatment within 3 months after an atrial fibrillation diagnosis in Denmark during 2012-18. Using routinely collected creatinine measurements from laboratory databases, we followed patients in an intention-to-treat approach for acute kidney injury (AKI) and chronic kidney disease (CKD) progression. We used propensity-score weighting to balance baseline confounders, computed weighted risks and weighted hazard ratios (HRs) with 95% confidence intervals (CIs) comparing DOACs with VKAs. We performed several subgroup analyses and a per-protocol analysis. Results: We included 32 781 persons with atrial fibrillation initiating oral anticoagulation (77% initiating DOACs). The median age was 75 years, 25% had a baseline estimated glomerular filtration rate <60 mL/min/1.73 m2, and median follow-up was 2.3 (interquartile range 1.1-3.9) years. The weighted 1-year risks of AKI were 13.6% in DOAC users and 15.0% in VKA users (HR 0.86, 95% CI 0.82; 0.91). The weighted 5-year risks of CKD progression were 13.9% in DOAC users and 15.4% in VKA users (HR 0.85, 95% CI 0.79; 0.92). Results were similar across subgroups and in the per-protocol analysis. Conclusions: Initiation of DOACs was associated with a decreased risk of AKI and CKD progression compared with VKAs. Despite the potential limitations of observational studies, our findings support the need for increased clinical awareness to prevent kidney complications among patients who initiate oral anticoagulants.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project.

BACKGROUND: The pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care. METHODS: Observational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019-2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments. RESULTS: A total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38-1.10) and after 60 days 0.89 (95% CI 0.45-1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups. CONCLUSION: We observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.

Glucose-lowering treatment pathways of individuals with chronic kidney disease and type 2 diabetes according to the Kidney Disease: Improving Global Outcomes 2012 risk classification.

AIMS: To describe treatment pathways for key glucose-lowering therapies in individuals with chronic kidney disease (CKD) and type 2 diabetes (T2D) using retrospective data from DISCOVER CKD (NCT04034992). METHODS: Data were extracted from the UK Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics data (2008-2020) and the US integrated Limited Claims and Electronic Health Records Database (LCED; 2012-2019). Eligible individuals were aged ≥18 years with CKD, identified by two consecutive estimated glomerular filtration rate (eGFR) measures (15-<75 mL/min/1.73 m2 ; 90-730 days apart; index date was the second measurement) and T2D. Chronological treatment pathways for glucose-lowering therapies prescribed on or after CKD index to end of follow-up were computed. Median time and proportion of overall follow-up time on treatment were described for each therapy by database and by eGFR and urinary albumin-to-creatinine ratio (UACR) categories. RESULTS: Of 36,951 and 4339 eligible individuals in the CPRD and LCED, respectively, median baseline eGFR was 67.8 and 64.9 mL/min/1.73 m2 ; 64.2 and 63.9% received metformin prior to index; and median (interquartile range) time on metformin during follow-up was 917 (390-1671) and 454 (192-850) days (accounting for ~75% of follow-up time in both databases). The frequency of combination treatment increased over time. There were trends towards decreased metformin prescriptions with decreasing eGFR and increasing UACR within each eGFR category. CONCLUSIONS: Individuals with CKD and T2D had many combinations of therapies and substantial follow-up time on therapy. These results highlight opportunities for improved CKD management.

Differences in the epidemiology, management and outcomes of kidney disease in men and women.

Improved understanding of differences in kidney disease epidemiology, management and outcomes in men and women could help nephrologists to better meet the needs of their patients from a sex- and gender-specific perspective. Evidence of sex differences in the risk and outcomes of acute kidney injury is mixed and dependent on aetiology. Women have a higher prevalence of chronic kidney disease (CKD) stages 3-5 than men, whereas men have a higher prevalence of albuminuria and hence CKD stages 1-2. Men show a faster decline in kidney function, progress more frequently to kidney failure and have higher mortality and risk of cardiovascular disease than women. However, the protective effect of female sex is reduced with CKD progression. Women are less likely than men to be aware of, screened for and diagnosed with CKD, started on antiproteinuric medication and referred to nephrologist care. They also consistently report a poorer health-related quality of life and a higher symptom burden than men. Women experience greater barriers than men to access the waiting list for kidney transplantation, particularly with respect to older age and obesity. However, women also have longer survival than men after transplantation, which may partly explain the comparable prevalence of transplantation between the sexes.

Accuracy of GFR estimating equations based on creatinine, cystatin C or both in routine care.

BACKGROUND: New equations to estimate glomerular filtration rate based on creatinine (eGFRcr), cystatin C (eGFRcys) or both (eGFRcr-cys) have been developed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and the European Kidney Function Consortium (EKFC). There is a need to evaluate the performance of these equations in diverse European settings to inform implementation decisions, especially among people with key comorbid conditions. METHODS: We performed a cross-sectional study including 6174 adults referred for single-point plasma clearance of iohexol in Stockholm, Sweden, with 9579 concurrent measurements of creatinine and cystatin C. We assessed the performance of the CKD-EPI 2009/2012/2021, EKFC 2021/2023, revised Lund-Malmö (RLM) 2011 and Caucasian, Asian, Pediatric and Adult (CAPA) 2014 equations against measured GFR (mGFR). RESULTS: Mean age was 56 years, median mGFR was 62 mL/min/1.73 m2 and 40% were female. Comorbid conditions were common: cardiovascular disease (30%), liver disease (28%), diabetes (26%) and cancer (26%). All eGFRcr-cys equations had small bias and P30 (the percentage of estimated values within 30% of mGFR) close to 90%, and performed better than eGFRcr or eGFRcys equations. Among eGFRcr equations, CKD-EPI 2009 and CKD-EPI 2021 showed larger bias and lower P30 than EKFC 2021 and RLM. There were no meaningful differences in performance across eGFRcys equations. Findings were consistent across comorbid conditions, and eGFRcr-cys equations showed good performance in patients with liver disease, cancer and heart failure. CONCLUSIONS: In conclusion, eGFRcr-cys equations performed best, with minimal variation among equations in this Swedish cohort. The lower performance of CKD-EPI eGFRcr equations compared with EKFC and RLM may reflect differences in population characteristics and mGFR methods. Implementing eGFRcr equations will require a trade-off between accuracy and uniformity across regions.

N-terminal pro-B-type natriuretic peptide concentrations, testing and associations with worsening heart failure events.

AIMS: In patients with heart failure (HF), we aimed to assess (i) the time trends in N-terminal pro-B-type natriuretic peptide (NT-proBNP) testing; (ii) patient characteristics associated with NT-proBNP testing; (iii) distribution of NT-proBNP levels, focusing on the subgroups with (WHFE) vs. without (NWHFE) a worsening HF event, defined as an HF hospitalization; and (iv) changes of NT-proBNP levels over time. METHODS AND RESULTS: NT-proBNP testing and levels were investigated in HF patients enrolled in the Swedish Heart Failure Registry (SwedeHF) linked with the Stockholm CREAtinine Measurements project from January 2011 to December 2018. Index date was the first registration in SwedeHF. Patterns of change in NT-proBNP levels before (in the previous 6 ± 3 months) and after (in the following 6 ± 3 months) the index date were categorized as follows: (i) <3000 ng/L at both measurements = stable low; (ii) <3000 ng/L at the first measurement and ≥3000 ng/L at the second measurement = increased; (iii) ≥3000 ng/L at the first measurement and <3000 ng/L at the second measurement = decreased; and (iv) ≥3000 ng/L at both measurements = stable high. Univariable and multivariable logistic regression models, expressed as odds ratios (ORs) and 95% confidence intervals (95% CIs), were performed to assess the associations between (i) clinical characteristics and NT-proBNP testing and (ii) changes in NT-proBNP from 6 months prior to the index date and the index date and a WHFE. Consistency analyses were performed in HF with reduced ejection fraction (HFrEF) alone. A total of 4424 HF patients were included (median age 74 years, women 34%, HFrEF 53%), 33% with a WHFE. NT-proBNP testing increased over time, up to 55% in 2018, and was almost two-fold as frequent, and time to testing was less than half, in patients with WHFE vs. NWHFE. Independent predictors of testing were WHFE, higher heart rate, diuretic use, and preserved ejection fraction. Median NT-proBNP was 3070 ng/L (Q1-Q3: 1220-7395), approximately three-fold higher in WHFE vs. NWHFE. Compared with stable low NT-proBNP levels, increased (OR 4.27, 95% CI 2.47-7.37) and stable high levels (OR 2.48, 95% CI 1.58-3.88) were independently associated with a higher risk of WHFE. Results were consistent in the HFrEF population. CONCLUSIONS: NT-proBNP testing increased over time but still was only performed in half of the patients. Testing was associated with a WHFE, with features of more severe HF and for differential diagnosis purposes. Increased and stable high levels were associated with a WHFE. Overall, our data highlight the potential benefits of carrying further implementation of NT-proBNP testing in clinical practice.

Intensity of and adherence to lipid-lowering therapy as predictors of goal attainment and major adverse cardiovascular events in primary prevention.

BACKGROUND: The effectiveness of lipid-lowering therapy (LLT) for primary prevention of atherosclerotic cardiovascular disease (ASCVD) in routine care may depend on treatment intensity and adherence. METHODS: Observational study of adults with newly initiated LLT for primary prevention of ASCVD in Stockholm, Sweden, during 2017-2021. Study exposures were LLT adherence [proportion of days covered (PDC)], LLT intensity (expected reduction of LDL cholesterol), and the combined measure of adherence and intensity. At each LLT fill, adherence and intensity were calculated during the previous 12 months, and the patients estimated ASCVD risk was categorized. Study outcomes were major adverse cardiovascular events (MACE) and LDL-C goal attainment. RESULTS: Thirty-six thousand two hundred eighty-three individuals (mean age 63 years, 47% women, median follow-up 2 years), with a baseline low-moderate (40%), high (49%), and very-high (11%) ASCVD risk started LLT. Increases in LLT adherence, intensity, or adherence-adjusted intensity of 10% over 1 year were associated with lower risks of MACE (with hazard ratios of 0.95 [95% CI, 0.93-0.98]; 0.93 [0.86-1.00]; and 0.90 [0.85-0.95], respectively) and higher odds of attaining LDL goals. Patients with good adherence (≥80%) had similar risks of MACE and similar odds ratios for LDL-C goal attainment with low-moderate and high-intensity LLT. Treatment discontinuation was associated with increased MACE risk. The relative and absolute benefits of good adherence were greatest in patients with very high ASCVD risk. CONCLUSION: In routine-care primary prevention, better adherence to LLT was associated with a lower risk of MACE across all treatment intensities. Improving adherence is especially important among patients with very high ASCVD risk.

Albuminuria and the risk of cancer: the Stockholm CREAtinine Measurements (SCREAM) project.

Background: Studies investigating the association of chronic kidney disease and cancer have focused on estimated glomerular filtration (eGFR) rather than on albuminuria. This study aimed to examine whether albuminuria is associated with cancer incidence, and whether this association is independent of eGFR. Methods: We included subjects of the Stockholm Creatinine Measurements (SCREAM) project without a history of cancer-250 768 subjects with at least one urine albumin-creatinine ratio (ACR) test (primary cohort) and 433 850 subjects with at least one dipstick albuminuria test (secondary cohort). Albuminuria was quantified as KDIGO albuminuria stages. The primary outcome was overall cancer incidence. Secondary outcomes were site-specific cancer incidence rates. Multivariable Cox proportional hazards regression models adjusted for confounders including eGFR to calculate hazard ratios and 95% confidence intervals (HRs, 95% CIs). Results: During a median follow-up of 4.3 (interquartile range 2.0-8.2) years, 21 901 subjects of the ACR cohort developed de novo cancer. In multivariable analyses, adjusting among others for eGFR, subjects with an ACR of 30-299 mg/g or ≥300 mg/g had a 23% (HR 1.23; 95% CI 1.19-1.28) and 40% (HR 1.40; 95% CI 1.31-1.50) higher risk of developing cancer, respectively, when compared with subjects with an ACR <30 mg/g. This graded, independent association was also observed for urinary tract, gastrointestinal tract, lung and hematological cancer incidence (all P < .05). Results were similar in the dipstick albuminuria cohort. Conclusions: Albuminuria was associated with the risk of cancer independent of eGFR. This association was primarily driven by a higher risk of urinary tract, gastrointestinal tract, lung and hematological cancers.

Kidney Function Measures and Mortality: A Mendelian Randomization Study.

RATIONALE & OBJECTIVE: Individuals with a low estimated glomerular filtration rate (eGFR) are at a high risk of death. However, the causes underpinning this association are largely uncertain. This study aimed to assess the causal relationship of low eGFR with all-cause and cause-specific mortality. STUDY DESIGN: Retrospective cohort study incorporating Mendelian randomization (MR). SETTING & PARTICIPANTS: Individual-level data from 436,214 White participants (54.3% female; aged 56.8±8.0 years) included in the UK Biobank. EXPOSURES: eGFR estimated using cystatin C (eGFRcyst). OUTCOMES: The outcomes of interest included all-cause mortality, cardiovascular mortality, cancer mortality, infection mortality, and other-cause mortality. ANALYTICAL APPROACH: Cox proportional hazards analysis for the conventional observational analyses; linear and nonlinear MR analyses implemented using genetic allele scores as instrumental variables representing kidney function to estimate the effect of kidney function on the survival outcomes. RESULTS: During a median follow-up of 12.1 years, there were 30,489 deaths, 6,098 of which were attributed to cardiovascular events, 15,538 to cancer, 1,516 to infection, and 7,227 to other events. In the conventional observational analysis, eGFRcyst exhibited a nonlinear association with all the outcomes. MR analysis suggested that a genetically predicted lower eGFRcyst was linearly associated with a higher rate of cardiovascular mortality (HR, 1.43; 95% CI, 1.18-1.75) across the entire measurement range (every 10-mL/min/1.73m2 decrement). Nonetheless, no causal associations between eGFRcyst and all-cause mortality (HR, 1.07; 95% CI, 0.98-1.17) or any types of noncardiovascular mortality were detected. LIMITATIONS: Potential misclassification of the actual cause of death, a nonrepresentative sample, and potential error in the interpretation of the magnitude of associations generated in MR analyses. CONCLUSIONS: These findings suggest a potential causal association between low eGFR and cardiovascular mortality in the general population, but no causal relationship with all-cause mortality or noncardiovascular mortality was observed. Further studies in other populations are warranted to confirm these findings. PLAIN-LANGUAGE SUMMARY: This study investigated the existence of a causal relationship between lower kidney function and death of different causes. Using data from 436,214 people in the United Kingdom, we applied conventional statistical analyses and those incorporating genetic data to implement Mendelian randomization, an approach that estimates causal associations. The observational analysis showed a nonlinear association between kidney function and various types of mortality outcomes. However, Mendelian randomization analysis suggested a linear increase in the risk of cardiovascular mortality with lower kidney function, but no causal link between the level of kidney function and all-cause or noncardiovascular mortality was identified. Managing kidney health may help reduce cardiovascular mortality, but caution is needed in interpreting the magnitudes of these results. Further validation in other populations and in those with advanced kidney failure is needed.

Associations of Estradiol With Mortality and Health Outcomes in Patients Undergoing Hemodialysis: A Prospective Cohort Study.

Background: Both lower and higher estradiol (E2) levels have been associated with increased mortality among women with kidney failure. However, robust data are still lacking. Objective: We investigated the interaction of diabetes and age on linear and nonlinear associations between E2 levels, adverse outcomes, and health-related quality of life (HRQOL) in Canadian women undergoing hemodialysis (HD). Design: Population-based cohort study; data from Canadian Kidney Disease Cohort Study (CKDCS). Setting & patients: A total of 427 women undergoing HD enrolled in the CKDCS. Measurements: Baseline E2 (in pmol/L) and E2 tertiles (<38 pmol/L, 38-95 pmol/L, >95 pmol/L). Methods: Cox-proportional hazards used for all-cause and cardiovascular disease (CVD) mortality. Fine-Gray models used for incident CVD. Mixed models used for Health Utilities Index Mark 3 (HUI3), Kidney Disease Quality of Life Physical Component Scores (KDQOL12-PCS), and Mental Component Scores (KDQOL12-MCS). Results: Over a median follow-up of 3.6 (interquartile range [IQR]: 1.6-7.5) years, 250 (58.6%) participants died; 74 deaths (29.6%) were CV-related. Among 234 participants without prior CV events, 80 (34.2%) had an incident CVD event. There were no significant linear associations between E2 and all-cause mortality, CVD mortality, and incident CVD. However, E2 showed a significant concave association with all-cause mortality, but not with CVD mortality and incident CVD. Among patients aged ≥63 years, higher E2 levels were associated with lower HUI3 scores, mean difference (MD) = -0.062 per 1 - SD pmol/L, 95% confidence interval (CI) = -0.112 to -0.012, but the opposite was observed in younger patients (<63 years) in whom higher E2 levels were associated with higher HUI3 scores (MD = 0.032 per 1 - SD pmol/L, 95% CI = 0.008-0.055), Pinteraction = .045. No associations were observed among E2, KDQOL12-PCS (MD = -0.15 per 1 - SD pmol/L, 95% CI = -1.15 to 0.86), and KDQOL12-MCS (MD = -0.63 per 1 - SD pmol/L, 95% CI = -1.82 to 0.57). Limitations: Unmeasured confounding and small sample size. Conclusions: The association between E2 and all-cause mortality may be nonlinear, while no association was observed for CVD mortality, incident CVD, KDQOL12-PCS, and KDQOL12-MCS. Furthermore, the association between serum E2 and HUI3 was modified by age: Higher levels were associated with higher utility among women aged <63 years and the converse observed among older women.

Contexte: Les taux faibles comme les taux élevés d'estradiol (E2) ont été associés à une mortalité accrue chez les femmes souffrant d'insuffisance rénale. Les données fiables à ce sujet font cependant encore défaut. Objectif: Nous avons étudié l'incidence du diabète et de l'âge sur les associations linéaires et non linéaires entre les niveaux d'E2, les issues défavorables et la qualité de vie liée à la santé (QVLS) chez les Canadiennes suivant des traitements d'hémodialyse (HD). Conception: Étude de cohorte en population réalisée à partir des données de la Canadian Kidney Disease Cohort Study (CKDCS). Sujets et cadre de l'étude: 427 femmes sous HD inscrites à la CKDCS. Mesures: Le taux d'E2 initial (pmol/L) et les taux d'E2 tertiles (<38 pmol/L; 38-95 pmol/L; >95 pmol/L). Méthodologie: Des modèles à risques proportionnels de Cox ont été utilisés pour mesurer la mortalité toutes causes confondues et la mortalité liée aux maladies cardiovasculaires (MCV). Des modèles Fine-Gray ont été utilisés pour mesurer les MCV incidentes; et des modèles mixtes ont été utilisés pour calculer l'indice Health Utilities Index Mark 3 (HUI3) et les scores des composantes physique (KDQOL12-PCS [Physical Component Score]) et mentale (KDQOL12-MCS [Mental Component Score])) du questionnaire sur la qualité de vie (KDQOL). Résultats: Au cours d'un suivi médian de 3,6 ans (intervalle interquartile [IIQ]: 1,6 à 7,5 ans), 250 participantes (58,6 %) sont décédées; 74 décès (29,6 %) étaient liés à un événement CV. Parmi les 234 participantes sans événements cardiovasculaires antérieurs, 80 (34,2 %) ont vécu un événement incident de MCV. Aucune association linéaire significative n'a été observée entre le taux d'E2 et la mortalité toutes causes confondues, la mortalité par MCV ou les MCV incidentes. Le taux d'E2 a cependant montré une association concave significative avec la mortalité toutes causes confondues, mais pas avec la mortalité par MCV ni avec les MCV incidentes. Chez les patientes âgées de 63 ans et plus, des taux élevés d'E2 ont été associés à des scores HUI3 plus faibles (différence moyenne [DM] = -0,062 par 1-SD pmol/L; intervalle de confiance à 95 % [IC95]: -0,112 à 0,012); alors qu'on a observé le contraire chez les patientes plus jeunes (< 63 ans), où des taux élevés d'E2 étaient plutôt associés à des scores plus élevés d'HUI3 (DM = 0,032 par 1-SD pmol/L; IC95: 0,008 à 0,055; p=0,045). Aucune association n'a été observée entre le taux d'E2, le KDQOL12-PCS (DM = -0,15 par 1-SD pmol/L; IC 95: -1,15 à 0,86) et le KDQOL12-MCS (DM = -0,63 par 1-SD pmol/L; IC95: -1,82 à 0,57). Limites: Facteurs de confusion non mesurés; échantillon de petite taille. Conclusion: Il pourrait exister une association non linéaire entre le taux d'E2 et la mortalité toutes causes confondues. Aucune association n'a toutefois été observée entre le taux d'E2 et la mortalité par MCV, les MCV incidentes, le KDQOL12-PCS et le KDQOL12-MCS. En outre, l'association entre le taux sérique d'E2 et l'HUI3 a été modifiée par l'âge: des taux plus élevés d'E2 ont été associés à un indice de santé plus élevé (HUI) chez les femmes âgées de moins de 63 ans, alors que l'inverse a été observé chez les femmes plus âgées.

Comparative Safety of Antidepressants in Adults with CKD.

BACKGROUND: Depression is prevalent in patients with CKD and is related to poor prognosis. Despite the widespread use of antidepressants in the CKD population, their safety remains unclear. METHODS: We identified adults with CKD stages G3-5 (eGFR <60 ml/min per 1.73 m2 not treated with dialysis) and incident depression diagnosis during 2007-2019 from the Stockholm Creatinine Measurements project. Using the target trial emulation framework, we compared the following treatment strategies: (1) initiating versus not initiating antidepressants, (2) initiating mirtazapine versus selective serotonin reuptake inhibitors (SSRIs), and (3) initiating SSRIs with a lower dose versus a standard dose. RESULTS: Of 7798 eligible individuals, 5743 (74%) initiated antidepressant treatment. Compared with noninitiation, initiation of antidepressants was associated with higher hazards of short-term outcomes, including hip fracture (hazard ratio [HR], 1.23; 95% confidence interval [CI], 0.88 to 1.74) and upper gastrointestinal bleeding (HR, 1.38; 95% CI, 0.82 to 2.31), although not statistically significant. Initiation of antidepressants was not associated with long-term outcomes, including all-cause mortality, major adverse cardiovascular event, CKD progression, and suicidal behavior. Compared with SSRIs, initiation of mirtazapine was associated with a lower hazard of upper gastrointestinal bleeding (HR, 0.52; 95% CI, 0.29 to 0.96), but a higher hazard of mortality (HR, 1.11; 95% CI, 1.00 to 1.22). Compared with the standard dose, initiation of SSRIs with a lower dose was associated with nonstatistically significantly lower hazards of upper gastrointestinal bleeding (HR, 0.68; 95% CI, 0.35 to 1.34) and CKD progression (HR, 0.80; 95% CI, 0.63 to 1.02), but a higher hazard of cardiac arrest (HR, 2.34; 95% CI, 1.02 to 5.40). CONCLUSIONS: Antidepressant treatment was associated with short-term adverse outcomes but not long-term outcomes in people with CKD and depression.

Cystatin C-based estimated glomerular filtration rate and risk of stroke in the general population: a prospective cohort study.

Background: Previous results on the association between the estimated glomerular filtration rate (eGFR) and stroke are mixed. Most studies derived the eGFR from serum creatinine, which is affected by non-kidney determinants and thus has possibly biased the association with stroke risk. Methods: In this cohort study, we included 429 566 UK Biobank participants (94.5% white, 54% women, age 56 ± 8 years) free of stroke at enrollment. The eGFRcys and eGFRcr were calculated with serum cystatin C and creatinine, respectively. Outcomes of interest were risk of total stroke and subtypes. We investigated the linear and nonlinear associations using Cox proportional hazards models and restricted cubic splines, corrected for regression dilution bias. Results: During an average follow-up of 10.11 years, 4427 incident strokes occurred, among which 3447 were ischemic and 1163 were hemorrhagic. After adjustment for confounders, the regression dilution-corrected hazard ratios (95% confidence intervals) for every 10 mL/min/1.73 m2 decrement in eGFRcys were 1.10 (1.05-1.14) for total stroke and 1.11 (1.08-1.15) for ischemic stroke. A similar pattern was observed with eGFRcr, although the association was weaker. When either type of eGFR was below 75 mL/min/1.73 m2, the risks of total and ischemic stroke increased exponentially as eGFR decreased. A U-shaped relationship was witnessed if eGFRcr was used instead. There was a null association between eGFR and hemorrhagic stroke. Conclusions: The risks of total stroke and ischemic stroke increased exponentially when the eGFRcys fell below 75 mL/min/1.73 m2.

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.