Kidney function, albuminuria, and their modification by genetic factors and risk of incident dementia in UK Biobank

BACKGROUND

Associations between kidney function and dementia risk are inconclusive. Chronic kidney disease (CKD) severity is determined by levels of both estimated glomerular filtration rate (eGFR) and the urine albumin to creatinine ratio (ACR). However, whether there is a graded increase in dementia risk for worse eGFR in each ACR category is unclear. Also, whether genetic risk for dementia impacts the associations is unknown. The current study aims to investigate the associations between eGFR and albuminuria with dementia risk both individually and jointly, whether the associations vary by different follow-up periods, and whether genetic factors modified the associations.

METHODS

In 202,702 participants aged ≥ 60 years from the UK Biobank, Cox proportional-hazards models were used to examine the associations between eGFR and urine albumin creatinine ratio (ACR) with risk of incident dementia. GFR was estimated based on serum creatinine, cystatin C, or both. The models were restricted to different follow-up periods (< 5 years, 5-10 years, and ≥ 10 years) to investigate potential reverse causation.

RESULTS

Over 15 years of follow-up, 6,042 participants developed dementia. Decreased kidney function (eGFR < 60 ml/min/1.73m2) was associated with an increased risk of dementia (Hazard Ratio [HR] = 1.42, 95% Confidence Interval [CI] 1.28-1.58), compared to normal kidney function (≥ 90 ml/min/1.73m2). The strength of the association remained consistent when the models were restricted to different periods of follow-up. The HRs for incident dementia were 1.16 (95% CI 1.07-1.26) and 2.24 (95% CI 1.79-2.80) for moderate (3-30 mg/mmol) and severely increased ACR (≥ 30 mg/mmol) compared to normal ACR (< 3 mg/mmol). Dose-response associations were observed when combining eGFR and ACR, with those in the severest eGFR and ACR group having the greatest risk of dementia (HR = 4.70, 95% CI 2.34-9.43). APOE status significantly modified the association (p = 0.04), with stronger associations observed among participants with a lower genetic risk of dementia. There was no evidence of an interaction between kidney function and non-APOE polygenic risk of dementia with dementia risk (p = 0.42).

CONCLUSIONS

Kidney dysfunction and albuminuria were individually and jointly associated with higher dementia risk. The associations were greater amongst participants with a lower genetic risk of dementia based on APOE, but not non-APOE polygenic risk.

Elevated urine albumin creatinine ratio increases cardiovascular mortality in coronary artery disease patients with or without type 2 diabetes mellitus: a multicenter retrospective study

BACKGROUND

Albuminuria has been suggested as an atherosclerotic risk factor among the general population. However, whether this association will be amplified in patients with coronary artery disease (CAD) is unknown. It is also unknown whether diabetes mellitus confounds the association. We aim to analyse the prognosis of elevated urine albumin creatinine ratio (uACR) in the CAD population with or without type 2 diabetes mellitus (T2DM).

METHODS

This multi-center registry cohort study included 5,960 patients with CAD. Patients were divided into T2DM and non-T2DM group, and baseline uACR levels were assessed on three grades (low: uACR < 10 mg/g, middle: 10 mg/g ≤ uACR < 30 mg/g, and high: uACR ≥ 30 mg/g). The study endpoints were cardiovascular mortality and all-cause mortality.

RESULTS

During the median follow-up of 2.2 [1.2-3.1] years, 310 (5.2%) patients died, of which 236 (4.0%) patients died of cardiovascular disease. CAD patients with elevated uACR had a higher risk of cardiovascular mortality (middle: HR, 2.32; high: HR, 3.22) than those with low uACR, as well as all-cause mortality. Elevated uACR increased nearly 1.5-fold risk of cardiovascular mortality (middle: HR, 2.33; high: HR, 2.34) among patients without T2DM, and increased 1.5- fold to 3- fold risk of cardiovascular mortality in T2DM patients (middle: HR, 2.49; high: HR, 3.98).

CONCLUSIONS

Even mildly increased uACR could increase the risk of cardiovascular mortality in patients with CAD, especially when combined with T2DM.

Diabetes Distress Is Associated With Future Risk of Progression of Diabetic Nephropathy in Adults With Type 2 Diabetes: A Prospective Cohort Study (Diabetes Distress and Care Registry at Tenri [DDCRT23])

OBJECTIVES

Our aim in this study was to investigate the prospective association between diabetes distress assessed with Problem Areas in Diabetes (PAID) survey scores at baseline and the subsequent risk of development or progression of diabetic nephropathy in people with type 2 diabetes.

METHODS

Longitudinal data were acquired from 2,845 individuals with type 2 diabetes registered in a Japanese diabetes registry. A Cox proportional hazards model was used to adjust for possible confounders to examine the prospective association between baseline diabetes distress (PAID score ≥40) and the development or progression of albuminuria.

RESULTS

Mean patient age, body mass index, and glycated hemoglobin level were 64.8 years, 24.5 kg/m2, and 57.4 mmol/mol (7.5%), respectively. We did not observe a significant association between diabetes distress and the subsequent risk of diabetic nephropathy development from normoalbuminuria to microalbuminuria/macroalbuminuria (multivariable-adjusted hazard ratio [HR]=0.95 over 4.2 years, 95% confidence interval [CI] 0.77 to 1.17, p=0.640); however, we identified a significant association for progression from microalbuminuria to macroalbuminuria (multivariable-adjusted HR=1.34 over 7.0 years, 95% CI 1.01 to 1.80, p=0.045). Stratification by sex revealed a significant association between diabetes distress and the subsequent risk of progressing diabetic nephropathy (HR=1.45, 95% CI 1.06 to 1.98, p=0.019) in males, but not females (HR=1.42, 95% CI 0.95 to 2.14, p=0.087).

CONCLUSIONS

Diabetes distress at baseline, assessed using the PAID survey, was associated with a subsequent risk of progressing diabetic nephropathy independent of possible confounders in males, but not females, with type 2 diabetes.

Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

Background

Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.

Methods

We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.

Results

We included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR (p=0.027, p=0.019, p<0.001, p<0.001, p=0.011 and respectively).

Conclusion

Upon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.

Genome-Wide Association Studies for Albuminuria of Nondiabetic Taiwanese Population

INTRODUCTION

Chronic kidney disease, which is defined by a reduced estimated glomerular filtration rate and albuminuria, imposes a large health burden worldwide. Ethnicity-specific associations are frequently observed in genome-wide association studies (GWAS). This study conducts a GWAS of albuminuria in the nondiabetic population of Taiwan.

METHODS

Nondiabetic individuals aged 30-70 years without a history of cancer were enrolled from the Taiwan Biobank. A total of 6,768 subjects were subjected to a spot urine examination. After quality control using PLINK and imputation using SHAPEIT and IMPUTE2, a total of 3,638,350 single-nucleotide polymorphisms (SNPs) remained for testing. SNPs with a minor allele frequency of less than 0.1% were excluded. Linear regression was used to determine the relationship between SNPs and log urine albumin-to-creatinine ratio.

RESULTS

Six suggestive loci are identified in or near the FCRL3 (p = 2.56 × 10-6), TMEM161 (p = 4.43 × 10-6), EFCAB1 (p = 2.03 × 10-6), ELMOD1 (p = 2.97 × 10-6), RYR3 (p = 1.34 × 10-6), and PIEZO2 (p = 2.19 × 10-7). Genetic variants in the FCRL3 gene that encode a secretory IgA receptor are found to be associated with IgA nephropathy, which can manifest as proteinuria. The PIEZO2 gene encodes a sensor for mechanical forces in mesangial cells and renin-producing cells. Five SNPs with a p-value between 5 × 10-6 and 5 × 10-5 are also identified in five genes that may have a biological role in the development of albuminuria.

CONCLUSION

Five new loci and one known suggestive locus for albuminuria are identified in the nondiabetic Taiwanese population.

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.

Estimated Prevalence and Testing for Albuminuria in US Adults at Risk for Chronic Kidney Disease

Importance

Albuminuria testing is crucial for guiding evidence-based treatments to mitigate chronic kidney disease (CKD) progression and cardiovascular morbidity, but it is widely underutilized among persons with or at risk for CKD.

Objective

To estimate the extent of albuminuria underdetection from lack of testing and evaluate its association with CKD treatment in a large US cohort of patients with hypertension or diabetes.

Design, Setting, and Participants

This cohort study examined adults with hypertension or diabetes, using data from the 2007 to 2018 National Health and Nutrition Examination Surveys (NHANES) and the Optum deidentified electronic health record (EHR) data set of diverse US health care organizations. Analyses were conducted from October 31, 2022, to May 19, 2023.

Main Outcomes and Measures

Using NHANES as a nationally representative sample, a logistic regression model was developed to estimate albuminuria (urine albumin-creatinine ratio ≥30 mg/g). This model was then applied to active outpatients in the EHR from January 1, 2017, to December 31, 2018. The prevalence of albuminuria among those with and without albuminuria testing during this period was estimated. A multivariable logistic regression was used to examine associations between having albuminuria testing and CKD therapies within the subsequent year (prescription for angiotensin-converting enzyme inhibitor [ACEi] or angiotensin II receptor blocker [ARB], prescription for sodium-glucose cotransporter 2 inhibitor [SGLT2i], and blood pressure control to less than 130/80 mm Hg or less than 140/90 mm Hg on the latest outpatient measure).

Results

The total EHR study population included 192 108 patients (mean [SD] age, 60.3 [15.1] years; 185 589 [96.6%] with hypertension; 50 507 [26.2%] with diabetes; mean [SD] eGFR, 84 [21] mL/min/1.73 m2). There were 33 629 patients (17.5%) who had albuminuria testing; of whom 11 525 (34.3%) had albuminuria. Among 158 479 patients who were untested, the estimated albuminuria prevalence rate was 13.4% (n = 21 231). Thus, only 35.2% (11 525 of 32 756) of the projected population with albuminuria had been tested. Albuminuria testing was associated with higher adjusted odds of receiving ACEi or ARB treatment (OR, 2.39 [95% CI, 2.32-2.46]), SGLT2i treatment (OR, 8.22 [95% CI, 7.56-8.94]), and having blood pressure controlled to less than 140/90 mm Hg (OR, 1.20 [95% CI, 1.16-1.23]).

Conclusions and Relevance

In this cohort study of patients with hypertension or diabetes, it was estimated that approximately two-thirds of patients with albuminuria were undetected due to lack of testing. These results suggest that improving detection of CKD with albuminuria testing represents a substantial opportunity to optimize care delivery for reducing CKD progression and cardiovascular complications.

Risk Factors for Incident CKD in Black and White Americans: The REGARDS Study

RATIONALE & OBJECTIVE

Little information exists on the incidence of and risk factors for chronic kidney disease (CKD) in contemporary US cohorts and whether risk factors differ by race, sex, or region in the United States.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

4,198 Black and 7,799 White participants aged at least 45 years, recruited from 2003 through 2007 across the continental United States, with baseline estimated glomerular filtration rate (eGFR)>60mL/min/1.73m2 and eGFR assessed again approximately 9 years later.

EXPOSURES

Age, sex, race (Black or White), region ("stroke belt" or other), education, income, systolic blood pressure, body mass index, diabetes, coronary heart disease, hyperlipidemia, smoking, and albuminuria.

OUTCOMES

(1) eGFR change and (2) incident CKD defined as eGFR<60mL/min/1.73m2 and≥40% decrease from baseline or kidney failure.

ANALYTICAL APPROACH

Linear regression and modified Poisson regression were used to determine the association of risk factors with eGFR change and incident CKD overall and stratified by race, sex, and region.

RESULTS

Mean age of participants was 63±8 (SD) years, 54% were female, and 35% were Black. After 9.4±1.0 years of follow-up, CKD developed in 9%. In an age-, sex-, and race-adjusted model, Black race (β =-0.13; P<0.001) was associated with higher risk of eGFR change, but this was attenuated in the fully adjusted model (β=0.02; P=0.5). Stroke belt residence was independently associated with eGFR change (β =-0.10; P<0.001) and incident CKD (relative risk, 1.14 [95% CI, 1.01-1.30]). Albuminuria was more strongly associated with eGFR change (β of-0.26 vs-0.17; P=0.01 for interaction) in Black compared with White participants. Results were similar for incident CKD.

LIMITATIONS

Persons of Hispanic ethnicity were excluded; unknown duration and/or severity of risk factors.

CONCLUSIONS

Established CKD risk factors accounted for higher risk of incident CKD in Black versus White individuals. Albuminuria was a stronger risk factor for eGFR decrease and incident CKD in Black compared with White individuals. Living in the US stroke belt is a novel risk factor for CKD.

Trajectories of renal biomarkers and new-onset heart failure in the general population: Findings from the PREVEND study

AIMS

Renal dysfunction is one of the most critical risk factors for developing heart failure (HF). However, the association between repeated measures of renal function and incident HF remains unclear. Therefore, this study investigated the longitudinal trajectories of urinary albumin excretion (UAE) and serum creatinine and their association with new-onset HF and all-cause mortality.

METHODS AND RESULTS

Using group-based trajectory analysis, we estimated trajectories of UAE and serum creatinine in 6881 participants from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study and their association with new-onset HF and all-cause death during the 11-years of follow-up. Most participants had stable low UAE or serum creatinine. Participants with persistently higher UAE or serum creatinine were older, more often men, and more often had comorbidities, such as diabetes, a previous myocardial infarction or dyslipidaemia. Participants with persistently high UAE had a higher risk of new-onset HF or all-cause mortality, whereas stable serum creatinine trajectories showed a linear association for new-onset HF and no association with all-cause mortality.

CONCLUSION

Our population-based study identified different but often stable longitudinal patterns of UAE and serum creatinine. Patients with persistently worse renal function, such as higher UAE or serum creatinine, were at a higher risk of HF or mortality.

Assessing the Burden of Kidney Disease among Type 2 Diabetic Subjects Attending a Semi-Urban Tertiary Health Facility in South-West Nigeria

BACKGROUND AND OBJECTIVES

Diabetes Mellitus (DM) remains an important public health issue and its complications are important causes of morbidity and mortality. Diabetic nephropathy (DN) is one of these complications and could be prevented/delayed by early detection. This study determined the burden of DN among patients with type 2 diabetes (T2DM).

METHODS

This cross-sectional, hospital-based study was conducted among 100 T2DM patients attending the medical outpatient clinics of a tertiary hospital in Nigeria and 100 age- and sex-matched healthy controls. The procedure included collection of sociodemographic parameters, urine for microalbuminuria and blood samples for estimation of fasting plasma glucose, glycated haemoglobin (HbA1c), and creatinine. Estimated creatinine clearance (eGFR) was derived from two formulae - Cockroft Gault formula, and Modification of Diet in Renal Disease study (MDRD) for staging chronic kidney disease. Data were analysed using the IBM SPSS version 23 software.

RESULTS

Participants' ages ranged from 28 years to 73 years [mean 53.0 (±10.7) years] with males accounting for 56% of the population and females 44%. Mean HbA1c was 7.6 (±1.8) % among the subjects; 59% had poor glycaemic control with HbA1c >7% (p-value <0.001). Overt proteinuria was present in 13% of T2DM participants while 48% had microalbuminuria compared to the non-diabetic group where 2% had overt proteinuria and 17% had microalbuminuria. Using the eGFR, chronic kidney disease was present in 14% of T2DM group and in 6% of the non-diabetic population. Increased age [OR= 1.09; 95%CI (1.03-1.14)], male sex [OR = 3.50; 95%CI (1.13 10.88)], and duration of diabetes [OR =1.01; 95%CI (1.00-1.01)] were associated with DN.

CONCLUSION

The burden of diabetic nephropathy is high in the T2DM patients attending our clinic and this is linked with advancing age.

Rationale and design of a prospective, clinical study of kidney biopsies in people with type 2 diabetes and severely increased albuminuria (the PRIMETIME 2 study)

INTRODUCTION

Diabetic kidney disease is a severe complication of diabetes. The diagnosis is based on clinical characteristics such as persistently elevated albuminuria, hypertension and decline in kidney function, although this definition is not specific to kidney disease caused by diabetes. The only way to establish an accurate diagnosis-diabetic nephropathy-is by performing a kidney biopsy. The histological presentation of diabetic nephropathy can be associated with a heterogeneous range of histological features with many pathophysiological factors involved demonstrating the complexity of the condition. Current treatment strategies aim to slow disease progression and are not specific to the underlying pathological processes.This study will investigate the prevalence of diabetic nephropathy in individuals with type 2 diabetes (T2D) and severely elevated albuminuria. The deep molecular characterisation of the kidney biopsy and biological specimens may pave the way for improved diagnostic accuracy and a better understanding of the pathological processes involved and may also reveal new targets for individualised treatment.

METHODS AND ANALYSIS

In the PRecIsion MEdicine based on kidney TIssue Molecular interrogation in diabetic nEphropathy 2 study, research kidney biopsies will be performed in 300 participants with T2D, urine albumin/creatinine ratio ≥700 mg/g and estimated glomerular filtration ratio >30 mL/min/1.73 m2. Cutting-edge molecular technologies will be applied to the kidney, blood, urine, faeces and saliva samples for comprehensive multi-omics profiling. The associated disease course and clinical outcomes will be assessed by annual follow-up for 20 years.

ETHICS AND DISSEMINATION

The Danish Regional Committee on Health Research Ethics and the Knowledge Center on Data Protection (in the Capital Region of Denmark) have granted approval for the study. The results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04916132.

Prevalence of Chronic Kidney Disease in China: Results From the Sixth China Chronic Disease and Risk Factor Surveillance

Importance

To our knowledge, there has been no update on the prevalence of chronic kidney disease (CKD) in China since 2012.

Objective

To provide periodic nationwide data on the prevalence of CKD and the associated behavioral and metabolic risk factors in China.

Design, Setting, and Participants

This nationally representative cross-sectional study included data from 176 874 adults from all 31 provincial-level administrative divisions in mainland China, as reported in the sixth China Chronic Disease and Risk Factor Surveillance conducted from August 2018 to June 2019. Data analysis was performed in 2021 to 2022.

Exposures

Serum creatinine, urinal creatinine, and urine albumin were measured for all participants. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine using the CKD-EPI equation.

Main Outcomes and Measures

The primary outcome was weighted prevalence of CKD in the overall population and different strata, defined as presence of impaired kidney function (eGFR of <60 mL/min/1.73m2) or albuminuria (urine albumin-to-creatinine ratio of ≥30 mg/g). Secondary outcomes were awareness of CKD and control of comorbidities. Logistic regression was used to examine the association of sociodemographic characteristics, behavioral and dietary habits, physical activity, and comorbidities with CKD.

Results

A total of 184 876 participants contributed data to this study, and of the 176 874 adults 18 years and older with measurements of eGFR and urine albumin-to-creatinine ratio in 2018 to 2019, the mean age was 43.8 years and the weighted proportion of women was 44.6%. The estimated prevalence of CKD, impaired kidney function, and albuminuria were 8.2%, 2.2%, and 6.7%, respectively. A higher prevalence of CKD was observed in the subgroups characterized by older age, female gender, non-Han ethnicity, residency of rural or north and central parts of China, receiving less education or lower income, former smoking, no alcohol drinking, lacking physical activity, and presence of risk factors such as obesity, hypertension, diabetes, dyslipidemia, and self-reported cardiovascular disease. Among the adults with CKD, 73.3%, 25.0%, and 1.8% were at stage 1 to 2, 3, and 4 to 5, respectively, and the awareness of CKD was 10.0%.

Conclusions and Relevance

This cross-sectional study found a weighted estimated of 82 million adults with CKD in China in 2018 to 2019. The prevalence appears to have decreased by 30% in the past decade. Better environmental protection, integration of CKD into the national public health surveillance program, and control of common CKD comorbidities appear to be associated with reducing the disease burden of CKD.

Prevalence, Cardiometabolic Comorbidities and Reporting of Chronic Kidney Disease; A Hungarian Cohort Analysis

Objectives: Chronic kidney disease (CKD) implies increased comorbidity burden, disability, and mortality, becoming a significant public health problem worldwide, however, prevalence data are lacking in Hungary.

Methods: We determined CKD prevalence, stage distribution, comorbidities using estimated glomerular filtration rate (eGFR), albuminuria, and international disease codes in a cohort of healthcare utilizing residents within the catchment area of the University of Pécs, in the County Baranya, Hungary, between 2011 and 2019 by database analysis. The number of laboratory-confirmed and diagnosis-coded CKD patients were compared.

Results: Of the total 296,781 subjects of the region, 31.3% had eGFR tests and 6.4% had albuminuria measurements, of whom we identified 13,596 CKD patients (14.0%) based on laboratory thresholds. Distribution by eGFR was presented (G3a: 70%, G3b: 22%, G4: 6%, G5: 2%). Amongst all CKD patients 70.2% had hypertension, 41.5% diabetes, 20.5% heart failure, 9.4% myocardial infarction, 10.5% stroke. Only 28.6% of laboratory-confirmed cases were diagnosis-coded for CKD in 2011–2019.

Conclusion: CKD prevalence was 14.0% in a Hungarian subpopulation of healthcare-utilizing subjects in 2011–2019, and substantial under-reporting of CKD was also found.

Elevated urine albumin-to-creatinine ratio increases the risk of new-onset heart failure in patients with type 2 diabetes

BACKGROUND

Although albuminuria has been linked to heart failure in the general population, the relationship between urine albumin-to-creatinine ratio (uACR) and heart failure in type 2 diabetes patients is not well understood. We aimed to investigate the relationship between uACR and new-onset heart failure (HF) in type 2 diabetics.

METHODS

We included 9287 Chinese participants with type 2 diabetes (T2D) but no heart failure (HF) who were assessed with uACR between 2014 and 2016. The participants were divided into three groups based on their baseline uACR: normal (< 3 mg/mmol), microalbuminuria (3-30 mg/mmol), and macroalbuminuria (≥ 30 mg/mmol). The relationship between uACR and new-onset HF was studied using Cox proportional hazard models and restricted cubic spline. The area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to see if incorporating uACR into existing models could improve performance.

RESULTS

216 new-onset HF cases (2.33%) were recorded after a median follow-up of 4.05 years. When compared to normal uACR, elevated uACR was associated with a progressively increased risk of new-onset HF, ranging from microalbuminuria (adjusted HR, 2.21; 95% CI 1.59-3.06) to macroalbuminuria (adjusted HR, 6.02; 95% CI 4.11-8.80), and 1 standard deviation (SD) in ln (uACR) (adjusted HR, 1.89; 95% CI 1.68-2.13). The results were consistent across sex, estimated glomerular filtration rate, systolic blood pressure, and glycosylated hemoglobin subgroups. The addition of uACR to established HF risk models improved the HF risk prediction efficacy.

CONCLUSIONS

Increasing uACR, even below the normal range, is an independent risk factor for new-onset HF in a type 2 diabetic population. Furthermore, uACR may improve HF risk prediction in community-based T2D patients.

Triglycerides and Renal Outcomes According to Albuminuria and in Consideration of Other Metabolic Syndrome Components in Diabetic US Veterans

INTRODUCTION

Hypertriglyceridemia, a component of the metabolic syndrome, is a known independent predictor of albuminuria and chronic kidney disease (CKD) in the general population. Previous studies have shown that the relationship of triglycerides (TGs) with outcomes changes across stages of CKD. Our objective was to examine the association of TG independent of other metabolic syndrome components with renal outcomes in diabetic patients with or without CKD.

METHODS

This retrospective cohort study included diabetic US veteran patients with valid data on TGs, estimated glomerular filtration rate (eGFR), and albuminuria (urinary albumin/creatinine ratio) between fiscal years 2004 and 2006. Using Cox models adjusted for clinical characteristics and laboratory markers, we evaluated the relationship of TG with incident albuminuria (stratified by eGFR category) and based on eGFR (stratified by baseline albuminuria categories). To evaluate the relationship of TG with time to end-stage renal disease (ESRD), we stratified models by baseline CKD stage (eGFR category) and baseline albuminuria stage ascertained at time of TG measurement.

RESULTS

In a cohort of 138,675 diabetic veterans, the mean ± SD age was 65 ± 11 years old and included 3% females and 14% African Americans. The cohort also included 28% of patients with non-dialysis-dependent CKD (eGFR <60 mL/min/1.73 m2), as well as 28% of patients with albuminuria (≥30 mg/g). The median (IQR) of serum TG was 148 (100, 222) mg/dL. We observed a slight positive linear association between TG and incident CKD after adjustment for Case-Mix and Laboratory variables among non-albuminuric and microalbuminuric patients. The relationship of high TG trended towards a higher risk of ESRD in CKD 3A non-albuminuric patients and in CKD 3A and 4/5 patients with microalbuminuria.

CONCLUSION

In a large cohort, we have shown that elevated TGs are associated with all kidney outcomes tested independently of other metabolic syndrome components in diabetic patients with normal eGFR and normal albumin excretion rate, but the association is weaker in some groups of diabetic patients with preexisting renal complications.

Association between Hypokalemia and Albuminuria in a Japanese General Population

INTRODUCTION

Hypokalemia is associated with an increased risk of chronic kidney disease (CKD) and is a risk factor for mortality. Albuminuria is an early manifestation of CKD. We investigated the association between hypokalemia and the prevalence of albuminuria in a Japanese general population.

METHODS

We analyzed the data of 18,289 subjects who underwent annual health checkups in 2018. We categorized them into four groups according to their concentration of serum potassium (sK) and performed a multivariate logistic regression analysis to determine the association between hypokalemia and the prevalence of albuminuria in this population. Hypokalemia was defined as having an sK = 3.1-3.5 mEq/L. After dividing the subjects into those with/without renal dysfunction, those with/without hypertension, and those with/without hyperglycemia, we examined the association between hypokalemia and albuminuria in each group.

RESULTS

Compared to the subjects with sK = 4.1-4.5 mEq/L, the subjects with hypokalemia had a significantly high prevalence of albuminuria: multivariable-adjusted odds ratio (OR) = 2.70 (95% confidence interval [CI] 1.84-3.96). The subgroup analyses showed the following multivariable-adjusted ORs (95% CIs) of the subjects: without renal dysfunction, 3.08 (2.00-4.73); with renal dysfunction, 2.05 (0.89-4.69); without hypertension, 2.89 (1.36-6.16); with hypertension, 2.60 (1.67-4.04); without hyperglycemia, 2.49 (1.62-3.84); and with hyperglycemia, 3.55 (1.43-8.79).

CONCLUSIONS

Hypokalemia was significantly associated with the high prevalence of albuminuria in general population. Regardless of the presence/absence of renal dysfunction, hypertension, or hyperglycemia, hypokalemia was positively associated with the prevalence of albuminuria, and the associations were significant except for the subjects with renal dysfunction.

Potential impact of NICE guidelines on referrals from primary care to nephrology: a primary care database and prospective research study

BACKGROUND

National Institute for Health and Care Excellence 2021 guidelines on chronic kidney disease (CKD) recommend the use of the Kidney Failure Risk Equation (KFRE), which includes measurement of albuminuria. The equation to calculate estimated glomerular filtration rate (eGFR) has also been updated.

AIM

To investigate the impact of the use of KFRE and the updated eGFR equation on CKD diagnosis (eGFR <60 mL/min/1.73 m2) in primary care and potential referrals to nephrology.

DESIGN AND SETTING

Primary care database (Secure Anonymised Information Linkage Databank [SAIL]) and prospective cohort study (UK Biobank) using data available between 2013 and 2020.

METHOD

CKD diagnosis rates were assessed when using the updated eGFR equation. Among people with eGFR 30-59 mL/min/1.73 m2 the following groups were identified: those with annual albuminuria testing and those who met nephrology referral criteria because of: a) accelerated eGFR decline or significant albuminuria; b) eGFR decline <30 mL/ min/1.73 m2 only; and c) KFRE >5% only. Analyses were stratified by ethnicity in UK Biobank.

RESULTS

Using the updated eGFR equation resulted in a 1.2-fold fall in new CKD diagnoses in the predominantly White population in SAIL, whereas CKD prevalence rose by 1.9-fold among Black participants in UK Biobank. Rates of albuminuria testing have been consistently below 30% since 2015. In 2019, using KFRE >5% identified 182/61 721 (0.3%) patients at high risk of CKD progression before their eGFR declined and 361/61 721 (0.6%) low-risk patients who were no longer eligible for referral. Ethnic groups 'Asian' and 'other' had disproportionately raised KFREs.

CONCLUSION

Application of KFRE criteria in primary care will lead to referral of more patients at elevated risk of kidney failure (particularly among minority ethnic groups) and fewer low-risk patients. Albuminuria testing needs to be expanded to enable wider KFRE implementation.

Including measures of chronic kidney disease to improve cardiovascular risk prediction by SCORE2 and SCORE2-OP

AIMS

The 2021 European Society of Cardiology (ESC) guideline on cardiovascular disease (CVD) prevention categorizes moderate and severe chronic kidney disease (CKD) as high and very-high CVD risk status regardless of other factors like age and does not include estimated glomerular filtration rate (eGFR) and albuminuria in its algorithms, systemic coronary risk estimation 2 (SCORE2) and systemic coronary risk estimation 2 in older persons (SCORE2-OP), to predict CVD risk. We developed and validated an 'Add-on' to incorporate CKD measures into these algorithms, using a validated approach.

METHODS

In 3,054 840 participants from 34 datasets, we developed three Add-ons [eGFR only, eGFR + urinary albumin-to-creatinine ratio (ACR) (the primary Add-on), and eGFR + dipstick proteinuria] for SCORE2 and SCORE2-OP. We validated C-statistics and net reclassification improvement (NRI), accounting for competing risk of non-CVD death, in 5,997 719 participants from 34 different datasets.

RESULTS

In the target population of SCORE2 and SCORE2-OP without diabetes, the CKD Add-on (eGFR only) and CKD Add-on (eGFR + ACR) improved C-statistic by 0.006 (95%CI 0.004-0.008) and 0.016 (0.010-0.023), respectively, for SCORE2 and 0.012 (0.009-0.015) and 0.024 (0.014-0.035), respectively, for SCORE2-OP. Similar results were seen when we included individuals with diabetes and tested the CKD Add-on (eGFR + dipstick). In 57 485 European participants with CKD, SCORE2 or SCORE2-OP with a CKD Add-on showed a significant NRI [e.g. 0.100 (0.062-0.138) for SCORE2] compared to the qualitative approach in the ESC guideline.

CONCLUSION

Our Add-ons with CKD measures improved CVD risk prediction beyond SCORE2 and SCORE2-OP. This approach will help clinicians and patients with CKD refine risk prediction and further personalize preventive therapies for CVD.

Estimated health economic impact of conducting urine albumin-to-creatinine ratio testing alongside estimated glomerular filtration rate testing in the early stages of chronic kidney disease in patients with type 2 diabetes

AIM

To estimate the health economic impact of undertaking urine albumin-to-creatinine ratio (UACR) testing versus no UACR testing in early stages of chronic kidney disease (CKD) progression in patients with type 2 diabetes (T2D).

METHODS

An economic model, taking a UK healthcare system perspective, estimated the impact of UACR testing on additional costs, clinical benefits measured as prevented dialyses and cardiovascular-related deaths, life years gained (LYg), LYg before kidney failure, and incremental cost-effectiveness ratio (ICER). Sixteen of the 18 Kidney Disease: Improving Global Outcomes (KDIGO) heatmap categories were considered separately, and grouped in health states according to CKD risk. Results were derived for current standard-of-care and emerging CKD therapies.

RESULTS

The cohort that adhered to both UACR and estimated glomerular filtration rate (eGFR) testing guidelines in early stages of CKD (n = 1000) was associated with approximately 500 LYg before kidney failure onset; costing approximately £2.5 M. ICERs across the KDIGO heatmap categories were approximately £5,000.

LIMITATIONS

This model used data from a comprehensive meta-analysis that was initiated more than 10 years ago (2009). While this was the most comprehensive source identified, recent changes in the treatment landscape, patient population and social determinants of CKD will not be captured. Furthermore, a narrow approach was taken, aligning included costs with UK NHS reference materials. This means that some direct and indirect drivers of costs in late-stage disease have been excluded.

CONCLUSIONS

UACR testing in the early stages of CKD is cost effective in T2D patients. Emerging therapies with the potential to slow CKD progression, mean that optimal monitoring through UACR/eGFR testing will become increasingly important for accurate identification and timely treatment initiation, particularly for the highest-risk A3 category.

The association of frailty with chronic kidney disease in older adults using the ASPirin in reducing events in the elderly cohort

Frailty and chronic kidney disease (CKD) both increase with age and are prevalent in older adults. However, studies in older adults examining the relationship between frailty and milder impairments of kidney function are relatively sparse. We examined the cross-sectional association of baseline estimated glomerular filtration rate (eGFR), albuminuria and CKD ([eGFR <60 ml/min/1.73 m2 ] and/or albuminuria [>3.0 mg/mmol]) with prefrailty and frailty in the ASPirin in Reducing Events in the Elderly (ASPREE) trial cohort of healthy older participants. Univariate logistic regression models measured the unadjusted odds ratios (OR) and 95% confidence intervals (CI) for prevalent combined prefrailty and frailty (respectively defined as presence of 1-2 or 3+ of 5 modified fried criteria) for the association between CKD, eGFR, albuminuria and other potential risk factors. Multivariable models calculated OR for prefrailty-frailty adjusted for potential confounders and either CKD, (i) eGFR and albuminuria measured as either continuous variables; (ii) or categorical variables; (iii). Of 17 759 eligible participants, 6934 were classified as prefrail, 389 were frail. CKD, eGFR and albuminuria were all associated with combined prefrailty-frailty on univariate analysis. In the multivariable modelling, neither CKD (reduced eGFR and/or albuminuria), nor eGFR (either continuous or categorical variables) were associated with prefrailty-frailty. However, albuminuria, either as a continuous variable (OR [95% CI] 1.07 [1.04-1.10]; p < .001), or categorical variable (OR 1.21 [1.08-1.36]; p = .001) was consistently associated with prefrailty-frailty. The complex relationship between albuminuria (which may be a biomarker for vascular inflammation), ageing, progressive CKD and frailty requires further investigation.

Protocol for a randomized study assessing the feasibility of home-based albuminuria screening among the general population: The THOMAS study

BACKGROUND

Chronic kidney disease (CKD) is a rising public health problem that may progress to kidney failure, requiring kidney replacement therapy. It is also associated with an increased incidence of cardiovascular disease (CVD). Because of its asymptomatic nature, CKD is often detected in a late stage. Population screening for albuminuria could allow early detection of people with CKD who may benefit from preventive treatment. In case such screening is performed in a general practitioner (GP) setting, this will result in relatively high costs. Home-based screening might be an effective and cost-effective alternative.

AIM

The THOMAS study (Towards HOMe-based Albuminuria Screening) is designed to prospectively investigate two methods for home-based population screening for increased albuminuria to detect yet undiagnosed CKD and risk factors for progression and CVD.

METHODS

This investigator initiated, randomized population-based study will include 15.000 individuals aged 45-80 years, who will be randomly assigned to be invited for a home-based screening test for albuminuria with a more conventional urine collection device or an innovative smartphone application. If the test result is positive upon confirmation (i.e., elevated albuminuria), participants are invited to a central screening facility for an elaborate screening for CKD and CVD risk factors. Participants are referred to their GP for appropriate treatment, if abnormalities are found. Primary endpoints are the participation rate, yield, and cost-effectiveness of the home-based screening and elaborate screening.

CONCLUSIONS

The THOMAS study will evaluate the effectiveness and cost-effectiveness of home-based albuminuria screening in the general population for the early detection of CKD and CVD risk factors. It will provide insight into the willingness to participate in population screening for CKD and into the compliance of the general population to a corresponding screening protocol and compliance to participate. Thus, it may help to develop an attractive novel screening strategy for the early detection of CKD.

TRIAL REGISTRATION

ClinicalTrials.gov, registration number NCT04295889, registered 05 March 2020. https://www.google.com/search?client=firefox-b-d&q=NCT04295889.

Association between glycemic control and albuminuria among Peruvian adults with diabetes mellitus 2: a cross-sectional analytical study

BACKGROUND

Albuminuria is a risk factor for microvascular and macrovascular complications in the diabetic population. However, few studies have correlated poor glycemic control and albuminuria prevalence in Hispanic populations.

OBJECTIVE

To evaluate the association between glycemic control and albuminuria among Peruvian adults with type 2 diabetes mellitus (T2DM).

DESIGN AND SETTING

Cross-sectional analytical study among adults with T2DM in Lima, Peru.

METHODS

We included adults over 18 years old who were in a clinical follow-up program at a private clinic in Lima in 2018. Poor glycemic control was defined as a serum value of glycosylated hemoglobin A1C (HbA1C) ≥ 7%. Albuminuria was defined as albumin values &gt; 30 mg/dl in the first morning urine. We generated generalized linear regression models from the Poisson family with robust variance. We calculated the crude and adjusted prevalence ratios (PRs) with their 95% confidence interval (CI).

RESULTS

We analyzed 907 participants of median age 58 years (interquartile range, IQR 49 to 66), and 62.8% were males. The prevalence of poor glycemic control was 39.8%, and the prevalence of albuminuria was 22.7%. The prevalences of albuminuria in groups with poor glycemic control and adequate glycemic control were 32.7% and 16.1%, respectively. In the adjusted regression analysis, we found a statistically significant association between poor glycemic control and albuminuria (annual percentage rate, aPR = 1.70; 95% CI: 1.28-2.27).

CONCLUSIONS

The prevalence of poor glycemic control and albuminuria was high in our study population. Moreover, Peruvian T2DM adults with poor glycemic control were more likely to have albuminuria.

Finerenone and Heart Failure Outcomes by Kidney Function/Albuminuria in Chronic Kidney Disease and Diabetes

BACKGROUND

In patients with type 2 diabetes (T2D), risks of cardiovascular mortality and heart failure (HF) increase with decreasing kidney function (estimated glomerular filtration rate [eGFR]) and increasing albuminuria (urine albumin-to-creatinine ratio [UACR]). Finerenone, a selective, nonsteroidal mineralocorticoid receptor antagonist, improved cardiorenal outcomes in patients with chronic kidney disease (CKD) and T2D in FIDELITY (Finerenone in Chronic Kidney Disease and Type 2 Diabetes: Combined FIDELIO-DKD and FIGARO-DKD Trial Programme Analysis).

OBJECTIVES

This study sought to evaluate the effects of finerenone on HF outcomes by eGFR and/or UACR categories.

METHODS

FIDELITY included 13,026 patients with T2D and CKD (UACR 30-5,000 mg/g and eGFR ≥25 mL/min/1.73 m2) randomized to finerenone or placebo. Time-to-event outcomes were first hospitalization for heart failure (HHF), cardiovascular death or first HHF, recurrent HHF, and cardiovascular death or recurrent HHF, analyzed in subgroups by baseline eGFR (<60 and ≥60 mL/min/1.73 m2) and/or UACR (<300 and ≥300 mg/g).

RESULTS

Compared with placebo, finerenone significantly reduced risk of first HHF (HR: 0.78 [95% CI: 0.66-0.92]; P = 0.003), cardiovascular death or first HHF (HR: 0.83 [95% CI: 0.74-0.93]; P = 0.002), recurrent HHF (HR: 0.79 [95% CI: 0.64-0.96]; P = 0.021), and cardiovascular death or recurrent HHF (HR: 0.82 [95% CI: 0.72-0.95]; P = 0.006). The risk of outcomes increased across baseline eGFR and UACR categories; lowest incidences were seen in patients with an eGFR ≥60 mL/min/1.73 m2 and a UACR <300 mg/g. Finerenone improved HF outcomes irrespective of baseline eGFR and/or UACR categories (all P interaction values >0.10).

CONCLUSIONS

Compared with placebo, finerenone improved HF-related outcomes in patients with CKD and T2D, with consistent benefits across eGFR and/or UACR categories. (Efficacy and Safety of Finerenone in Subjects With Type 2 Diabetes Mellitus and Diabetic Kidney Disease [FIDELIO-DKD], NCT02540993; Efficacy and Safety of Finerenone in Subjects With Type 2 Diabetes Mellitus and the Clinical Diagnosis of Chronic Kidney Disease [FIGARO-DKD], NCT02545049).

[Chronic kidney disease in community: Current state for screening and management]

OBJECTIVE

To understand the current state and problem of screening and management of chronic kidney disease (CKD) in the community, and to explore the improving strategies.

METHODS

We established a community-CKD integrated data science platform based on medical information from 79 community health centers, in Xicheng District, Beijing. Patients who referred to 79 community health centers from 21 June 2015 to 20 November 2021 were retrospectively included in this study using the CKD data platform. The monitoring of the indicator of kidney injury, risk factor control, medicine use and device configuration in community were assessed in the study.

RESULTS

In the study, 70.6% of the population were identified with high risk of CKD in the total 374 498 individuals who referred to the community health centers. Hypertension (62.3%), coronary heart disease (43.3%) and diabetes (30.4%) were the most common risk factors in high-risk CKD population. Only 17.2% of the patients with high risk of CKD were screened for kidney injury including at least one serum creatine (Scr) or albuminuria test, among which 10 992 (24.2%) individuals were defined as CKD. 22.7% (11 338/49 908) of the total patients with kidney screening in community were defined as CKD, of whom, 42.6% and 46.1% were identified by estimated glomerular filtration rate (eGFR) < 60 mL/(min·1.73 m²) and abnormalities of urinary proteins, respectively. The overall CKD detection rate in the community was 5.2% (19 299/374 498), and the miss-diagnosis rate of CKD was 38.1%. Of the 79 community health centers, 13 (16.5%) were equipped with ACR testing device, and eGFR was reported directly in 66 (83.5%) centers. Altogether 60.3% and 99.7% of the community CKD patients achieved glucose control and blood pressure control, respectively, and 59.3% of the CKD patients who had proteinuria was treated with renin-angiotensin-aldosterone system (RAAS) inhibitors.

CONCLUSION

High-risk CKD population account for a substantial proportion of patients who refer to the community. Early screening, prevention and management of CKD in the community are of great importance to improve the prognosis and decrease the burden of CKD. It's essential to establish a screening and monitoring system, strengthen standardized management and clinician training for improving the ability of CKD management in the community.

Effect of the nurse-led program on blood glucose control and microalbuminuria development in type 2 diabetic populations

Current study was to evaluate whether the nurse-led program can improve glycated hemoglobin (HbA1c) control and reduce the incidence of microalbuminuria in type 2 diabetic mellitus (DM2) populations. A total of 150 DM2 subjects were randomly assigned to the usual-care group and nurse-led program group. Study endpoints included the HbA1c value, the percentage of subjects with HbA1c < 7.0%, the incidence of microalbuminuria, and the rate of adhering to antidiabetic drug at 6 months' follow-up. At baseline, there was no difference in fasting plasma glucose, HbA1c, proportion of subjects with HbA1c < 7.0%, the use of antidiabetic drug, and urinary albumin-creatinine ratio between these two groups. After 6 months' follow-up, the mean fasting plasma glucose and HbA1c were lower in the nurse-led program group, as was the proportion of subjects with HbA1c < 7.0%. The median urinary albumin-creatinine ratio and rate of incident microalbuminuria were also lower in the nurse-led program. The nurse-led program was associated with higher odds of achieving HbA1c < 7.0% and a lower incidence of microalbuminuria. After adjusted for covariates, the nurse-led program was still associated with 32% higher odds of achieving HbA1c < 7.0% and 11% lower incidence of microalbuminuria. These benefits were consistent by sex and age, while greater in those with obesity or hypertension (P interaction < .05). The nurse-led program is beneficial for blood glucose control and prevention of microalbuminuria.

Prevalence of Microalbuminuria in Patients of Essential Hypertension and its Correlation with Left Ventricular Hypertrophy and Carotid Artery Intima‑media Thickness

Background Urinary albumin excretion has been associated to cardiovascular events and increased mortality in hypertensive patients. There is limited information among Nepalese patients about the implications of microalbuminuria (MA) in the setting of hypertension and potential cardiovascular morbidity. Objective To investigate the prevalence of microalbuminuria in patients with essential hypertension and its connection with left ventricular hypertrophy (LVH) and carotid artery intima-media thickness (cIMT). Method The study involved 80 hypertension individuals in total. All patients in the study had basic biochemical tests, routine urine evaluations, echocardiography, and carotid artery intima-media thickness measurements performed, and the data were analyzed. Result The prevalence of microalbuminuria was present in 37.5% cases of essential hypertension. The mean left ventricular mass index (LVMI) was significantly higher in patients with increased microalbuminuria as compared to patient with normal microalbuminuria. In addition, a significant positive correlation between microalbuminuria and left ventricular hypertrophy was also observed. Furthermore, mean carotid artery intima-media thickness was found to be higher in patients with microalbuminuria (p < 0.001), with 76.7% of the patients with microalbuminuria having elevated mean carotid artery intima-media thickness. The carotid artery intima-media thickness had a positive correlation with both microalbuminuria and left ventricular hypertrophy. Conclusion Microalbuminuria assessment in hypertensive patients is an important test for the evaluation of target organ damage. This study shows that microalbuminuria is common in hypertension patients, particularly those with left ventricular hypertrophy. Microalbuminuria was found to be associated with left ventricular hypertrophy and carotid artery intima-media thickness.

Sex Differences in the Recognition, Monitoring, and Management of CKD in Health Care: An Observational Cohort Study

INTRODUCTION

Reported sex differences in the etiology, population prevalence, progression rates, and health outcomes of people with CKD may be explained by differences in health care.

METHODS

We evaluated sex as the variable of interest in a health care-based study of adults (n=227,847) with at least one outpatient eGFR<60 ml/min per 1.73 m2 measurement denoting probable CKD in Stockholm from 2009 to 2017. We calculated the odds ratios for diagnosis of CKD and provision of RASi and statins at inclusion, and hazard ratios for CKD diagnosis, visiting a nephrologist, or monitoring creatinine and albuminuria during follow-up.

RESULTS

We identified 227,847 subjects, of whom 126,289 were women (55%). At inclusion, women had lower odds of having received a diagnostic code for CKD and were less likely to have received RASi and statins, despite having guideline-recommended indications. In time-to-event analyses, women were less likely to have received a CKD diagnosis (HR, 0.43; 95% CI, 0.42 to 0.45) and visited a nephrologist (HR, 0.46; 95% CI, 0.43 to 0.48) regardless of disease severity, presence of albuminuria, or criteria for referral. Women were also less likely to undergo monitoring of creatinine or albuminuria, including those with diabetes or hypertension. These differences remained after adjustment for comorbidities, albuminuria, and highest educational achievement, and among subjects with confirmed CKD at retesting. Although in absolute terms all nephrology-care indicators gradually improved over time, the observed sex gap persisted.

CONCLUSIONS

There were profound sex differences in the detection, recognition, monitoring, referrals, and management of CKD. The disparity was also observed in people at high risk and among those who had guideline-recommended indications.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2022_10_11_JASN2022030373.mp3.

Chronic kidney disease and cognitive decline in patients with type 2 diabetes at elevated cardiovascular risk

AIMS

We addressed the question whether chronic kidney disease (CKD) may contribute to cognitive decline in type 2 diabetes.

METHODS

Participants with type 2 diabetes with elevated cardiovascular risk or CKD from cognition substudies of two large trials were studied prospectively (CARMELINA: n = 2666, mean ± SD age 68.1 ± 8.7 years, CAROLINA: n = 4296; 64.7 ± 9.4 years). Estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) at baseline were related to cognitive performance (Mini-Mental State Examination (MMSE) and attention and executive functioning score (A&E)) in linear regression analyses, adjusted for demographics, cardiovascular risk factors and treatment, at baseline and follow-up.

RESULTS

CKD at baseline was more common in CARMELINA than CAROLINA (eGFR<60 in 72.6 % and 19.6 %, macroalbuminuria in 35.0 % and 4.1 %, respectively). Baseline eGFR was related to A&E in CARMELINA (b = 0.02 per 10 ml/min/1.73m², 95%CI [0.01,0.03]). Baseline UACR was related to A&E in CAROLINA (b = -0.01 per doubling of UACR mg/g, 95%CI [-0.02,-0.002]). Baseline UACR predicted decline in A&E in CAROLINA (median 6.1 years follow-up; b = -0.01, 95%CI [-0.03,-0.0001] per doubling of UACR mg/g).

CONCLUSIONS

eGFR and UACR were associated with A&E in two cohorts with type 2 diabetes, enriched for CKD and cardiovascular disease. The small effect size estimates indicate limited impact of kidney dysfunction on cognition in this setting.

GOV IDENTIFIERS

NCT01897532 NCT01243424.

The bidirectional association between depressive symptoms, assessed by the HADS, and albuminuria–A longitudinal population-based cohort study with repeated measures from the HUNT2 and HUNT3 Study

Background

Both albuminuria and depression are associated with cardiovascular disease, reflecting low-grade systemic inflammation and endothelial dysfunction. They share risk factors including weight, blood pressure, smoking and blood glucose levels. This longitudinal study aimed to examine bidirectional associations between depression symptoms, indexed by the Hospital Anxiety and Depression scale (HADS), and the inflammation marker albuminuria.

Methods

2909 persons provided urine samples in both the second (HUNT2, 1995–97) and third wave (HUNT3, 2006–2008) of the Trøndelag Health Survey, Norway. We used a generalized linear regression model (GLM) and ANOVA to assess the association between albuminuria levels (exposure HUNT2) with depression symptoms (outcome in HUNT3); and between depression symptoms (exposure HUNT2) with albuminuria (outcome HUNT3). Depression symptoms were measured with the HADS Depression Scale, analyzed utilising the full 7 items version and analyses restricted to the first 4 items (HADS-D and HADS-4). We accounted for confounders including baseline individual levels of the exposure variables.

Results

In this 10-years follow-up study, we found no statistical evidence for an association between baseline depression symptoms and subsequent albuminuria, nor between baseline albuminuria and subsequent depression symptoms. For albuminuria, only 0.04% was explained by prior depression, and for depression, only 0.007% was explained by previous albuminuria levels. The results were essentially the same for the shorter HADS-4 measure.

Conclusion

There does not appear to be a longitudinal association between albuminuria and depression measured by the HADS.

Association of microalbuminuria with serum lipids and inflammatory markers in an adult population in the Dikgale Health and Demographic Surveillance System site, South Africa

BACKGROUND

There is evidence that microalbuminuria (urinary albumin excretion) is an early sign of vascular damage and an established risk factor for cardiovascular morbidity and mortality. This study investigated the magnitude of microalbuminuria and its association with serum lipids and inflammatory markers among a rural black population residing in the Dikgale Health and Demographic Surveillance System site, South Africa.

METHODS

Data were collected from 602 presumably healthy participants (225 men and 377 women) aged ≥ 18 years. Biochemical data collection included serum lipids, glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), urine albumin and creatinine. Anthropometry and blood pressure were also measured. Microalbuminuria was diagnosed with an albumin-creatinine ratio of ≥ 2.5 mg/mmol in men and ≥ 3.5 mg/mmol in women. Data were analysed using SPSS version 22.0.

RESULTS

The mean age of participants was 48.63 ± 20.89 years. High percentages of microalbuminaria (35.7%), high levels of interleukin 6 (17.8%), hs-CRP (32.9%), triglycerides (TG) (26.1%), low-density lipoprotein cholesterol (52.2%) and total cholesterol (32.0%), and low levels of high-density lipoprotein cholesterol (29.1%) were observed in the population. Increased glucose levels (32.8%), insulin resistance (27.6%), hypertension (45.8%), overweight (26.8%) and obesity (25.4%) were also prevalent. Microalbuminuria was associated with high hs-CRP and TG levels in the men (adjusted odds ratios = 9.434, 95% confidence interval: 1.753 - 50.778, p = 0.01).

CONCLUSIONS

High prevalence of microalbuminuria, hypertension, insulin resistance, overweight and obesity, as well as abnormal levels of serum lipids and inflammatory markers were observed in the population. Microalbuminuria was associated with high hs-CRP and TG levels among men.

Analysis of cadmium accumulation in community adults and its correlation with low-grade albuminuria

OBJECTIVE

To investigate the effects of chronic non-occupational exposure to cadmium (Cd) on renal injury in residents living in the urban areas of China.

METHODS

In this cross-sectional study, we recruited 1000 participants in Shanghai from August 2015 to August 2017 and collected data on their socio-demographic characteristics, lifetime occupation, and lifestyle factors. The urinary Cd, urinary albumin, urinary creatinine, serum creatinine, urea, and uric acid levels were tested, and 683 participants completed those measurements.

RESULTS

The median urinary Cd concentration of this study population was 0.77 μg/g. The urinary Cd concentration was significantly higher in the female, older, and lower body mass index populations. There were 148 participants with dominant albuminuria who had higher urinary Cd levels than those without dominant albuminuria (0.98 vs. 0.72 μg/g; P < 0.001). Among participants without dominant albuminuria, there were 134 participants with low-grade albuminuria (13.84 ≤ ACR < 30 mg/g) and 401 participants who had normal urinary albumin excretion (ACR < 13.84 mg/g). Compared with those who had normal urinary albumin excretion, those with low-grade albuminuria had significantly higher urinary Cd levels (0.83 vs. 0.69 μg/g; P < 0.001). Among those without dominant albuminuria, participants in the highest quartile of urinary Cd were more likely to have low-grade albuminuria than those in the lowest quartile (Odd's ratio = 2.98; P < 0.001). Further adjustment for age, sex, and BMI or other potential confounding factors did not change the magnitudes of the associations. Moreover, we conducted multivariable stepwise linear regression analysis within 134 low-grade albuminuria participants and demonstrated that urinary Cd concentration (P < 0.001) were independent determinants of urine albumin after adjusting for relevant confounders.

CONCLUSION

The urinary Cd levels observed in Chinese urban adults are substantial and associated with an increased risk of low-grade albuminuria. Our findings suggest that potential sources of environmental Cd exposure should be explored, and the associated renal toxicity should be studied in more detail in future.

24-Hour ambulatory blood pressure monitoring 7 years after intensive care unit admission

BACKGROUND

Children who develop acute kidney injury (AKI) in the pediatric intensive care unit (PICU) may be at higher risk of long-term chronic kidney disease and hypertension. The objectives of this study were to determine the prevalence of post-discharge hypertension and albuminuria using reference-standard measurements in children admitted to the PICU, and evaluate their association with AKI.

METHODS

Single-center longitudinal cohort study of children admitted to the PICU from 2005 to 2010 with 7-8 years of follow-up (n = 207). Patients were excluded if they had pre-existing chronic kidney disease, were deceased, lived > 3.5-h drive away, were unwilling/unable to provide consent/assent, or had a clotting disorder. AKI was defined by the Kidney Disease: Improving Global Outcomes creatinine definition. Office blood pressure was evaluated using age, sex, and height-based percentiles. Hypertension was defined using 24-h ambulatory blood pressure monitoring (ABPM). Albuminuria was defined as first morning urine albumin:creatinine ratio ≥ 30 mg/g. Prevalence of blood pressure outcomes was calculated. The association between AKI and outcomes was evaluated using multivariable regression.

RESULTS

Sixty of 207 (29%) children developed AKI during PICU admission. Overall, 6% had albuminuria and 21% had elevated office blood pressure or worse. One-hundred-and-seventy-seven (86%) patients had successful ABPM data. Of these, 10 (6%) had white coat, 18 (10%) had masked, and 5 (3%) had ambulatory hypertension. There was no statistically significant difference in outcomes across AKI stages.

CONCLUSIONS

Blood pressure abnormalities are common in children 7 years after PICU admission. Future studies with longer follow-up are needed to further evaluate the association between AKI and hypertension. A higher-resolution version of the graphical abstract is available as Supplementary information.

Non-alcoholic fatty liver disease and sarcopenia is associated with the risk of albuminuria independent of insulin resistance, and obesity

BACKGROUND

Although non-alcoholic fatty liver disease (NAFLD) is associated with metabolic disorders, its influence on albuminuria has not been determined. The aim of this study was to identify the relationship between NAFLD and albuminuria in the general Korean population.

METHODS

Data from the Korea National Health and Nutrition Examination Surveys (KNHANES) of 2008-2011 were analyzed (n = 1795). Albuminuria was defined as an albumin-to-creatinine ratio of ≥30 mg/g in random spot urine samples. NAFLD was defined as a fatty liver index (FLI) ≥60 or NAFLD liver fat score (LFS) > -0.64.

RESULTS

A total of 289 (16.1 %) subjects were classified as having albuminuria. Subjects with NAFLD exhibited a higher rate of albuminuria than subjects without NAFLD (crude odds ratios [ORs] = 2.60-2.95, all P < 0.001). Regardless of hypertension, insulin resistance, or obesity, the risk for albuminuria was higher in the NAFLD group than in the group without NAFLD (measured by either FLI or LFS; all P < 0.001). When subjects with NAFLD had sarcopenia, the risk of albuminuria further increased (OR = 4.33-4.64, all P < 0.001). Multiple logistic regression analyses also demonstrated that NAFLD was independently associated with albuminuria (OR = 2.58, 95 % confidence interval [CI] = 1.66-4.02, P < 0.001 for FLI, OR = 1.87, 95 % CI = 1.28-2.75, P = 0.001 for LFS).

CONCLUSIONS

NAFLD was associated with an increased risk of albuminuria in the general Korean population. This association was independent of hypertension, insulin resistance, chronic kidney disease, diabetes and obesity, and stronger in subjects with sarcopenia.

Rationale, design and baseline characteristics of the effect of canagliflozin in patients with type 2 diabetes and microalbuminuria in the Japanese population: The CANPIONE study

AIM

To evaluate the effect of canagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, on albuminuria and the decline of estimated glomerular filtration rate (eGFR) in participants with type 2 diabetes and microalbuminuria.

METHODS

The CANPIONE study is a multicentre, randomized, parallel-group and open-labelled study consisting of a unique 24-week preintervention period, during which the rate of eGFR decline before intervention is estimated, followed by a 52-week intervention and a 4-week washout period. Participants with a geometric mean urinary albumin-to-creatinine ratio (UACR) of 50 and higher and less than 300 mg/g in two consecutive first-morning voids at two different time points, and an eGFR of 45 ml/min/1.73m² or higher, are randomly assigned to receive canagliflozin 100 mg daily or to continue guideline-recommended treatment, except for SGLT2 inhibitors. The first primary outcome is the change in UACR, and the second primary outcome is the change in eGFR slope.

RESULTS

A total of 258 participants were screened and 98 were randomized at 21 sites in Japan from August 2018 to May 2021. The mean baseline age was 61.4 years and 25.8% were female. The mean HbA1c was 7.9%, mean eGFR was 74.1 ml/min/1.73m² and median UACR was 104.2 mg/g.

CONCLUSIONS

The CANPIONE study will determine whether the SGLT2 inhibitor canagliflozin can reduce albuminuria and slow eGFR decline in participants with type 2 diabetes and microalbuminuria.

Isolated diastolic hypertension in childhood and risk of adult subclinical target organ damage: a 30-year prospective cohort study

BACKGROUND

Data on the association of isolated diastolic hypertension (IDH) in childhood with adult cardiovascular risk are scarce. This study aimed to estimate the prevalence of IDH in adolescents and to explore the impact of IDH in childhood on adult subclinical target organ damage (STOD).

METHODS

This longitudinal study consisted of 1738 school children (55.4% boys) aged 6-15 years from rural areas of Hanzhong, Shaanxi, who were followed for 30 years. Their blood pressure was recorded to define the hypertension subtypes: normotension, IDH, isolated systolic hypertension (ISH) and mixed hypertension. Tracked STOD included arterial stiffness ( n  = 1738), albuminuria ( n  = 1652) and left ventricular hypertrophy (LVH) ( n  = 1429).

RESULTS

Overall, the prevalence of IDH, ISH and mixed hypertension was 5.4, 2.2 and 3%, respectively, and there was no gender difference. Over 30 years, 366 (21.1%) of participants developed arterial stiffness, 170 (10.3%) developed albuminuria and 68 (4.8%) developed LVH. Compared with normotensive participants, IDH in childhood had higher risk ratio (RR) of experiencing arterial stiffness (RR, 1.66; 95% CI, 1.01-2.76) and albuminuria (RR, 2.27; 95% CI, 1.35-4.16) in adults after being fully adjusted but not LVH. However, if the elevated blood pressure in children was used as the reference standard, IDH in childhood was associated with adult LVH (RR, 2.48; 95% CI, 1.28-4.84).

CONCLUSION

IDH accounts for a higher proportion of adolescent hypertension subtypes and can increase the risk of adult STOD. These results highlight the necessity of improving the prevention, detection and treatment of IDH in adolescents.

Sodium-glucose cotransporter 2 inhibitors as adjunct therapy for type 1 diabetes and the benefit on cardiovascular and renal disease evaluated by Steno risk engines

AIMS

Sodium-glucose cotransporter inhibitors (SGLTi) have beneficial cardiovascular and renal effects in persons with type 2 diabetes. No studies have shown whether this can be demonstrated in type 1 diabetes (T1D). We aimed to estimate the risk of cardiovascular disease (CVD) and end-stage kidney disease (ESKD) in persons with T1D with and without treatment with SGLTi.

METHODS

The study is based on 3660 adults with T1D. The Steno Type 1 Risk Engines were used to calculate 5-year risks of ESKD and 5- and 10-year risk of CVD. The effect of SGLTi was simulated by changing the HbA_1c and systolic blood pressure values in accordance with results from the DEPICT studies with mean (standard deviation (SD)) of -3.6 (0.9) mmol/mol (-2.5 % (2.2)) and -1.12 (2.8) mmHg. eGFR and albuminuria were changed in accordance with results from the Tandem studies; no change in eGFR and mean (SD) %-change in albuminuria of -23.7 (12.9).

RESULTS

We found a 5-year CVD relative risk reduction of 6.1 % (95%CI 5.9,6.3) and 11.1 % (10.0,12.2) in the subgroup with albuminuria with similar results for the 10-year CVD risk. For the estimated 5-year risk of ESKD, we found a relative risk reduction of 5.3 % (5.1,5.4) with 7.6 % (6.9,8.4) in the subgroup with albuminuria.

CONCLUSION

We found a significant CVD and ESKD risk reduction, especially in the subgroup with albuminuria.

Association of Albuminuria and Regression of Chronic Kidney Disease in Adults With Newly Diagnosed Moderate to Severe Chronic Kidney Disease

IMPORTANCE

People with chronic kidney disease (CKD) are risk-stratified for adverse events based on estimated glomerular filtration rate (eGFR) and albuminuria level. CKD has often a favorable course (CKD regression) regardless of eGFR. Determining whether lower albuminuria is associated with CKD regression may have implications on CKD management.

OBJECTIVE

To assess the 5-year probability of CKD regression across albuminuria categories accounting for the competing risks of CKD progression and death in people with newly diagnosed CKD and the association between albuminuria level and CKD regression.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used administrative and laboratory data from Alberta, Canada, for adults with incident moderate to severe CKD (defined as sustained eGFR of 15-44 mL/min/1.73 m2 for >90 days), between April 1, 2008, and March 31, 2017, and albuminuria measures before cohort entry. Data analysis occurred in January to June 2022.

EXPOSURE

Albuminuria categories were defined by albumin to creatinine ratios (ACRs): A1 (ACR, <3 mg/mmol), A2 (ACR, 3-29 mg/mmol), A3<60 (ACR, 30-59 mg/mmol), and A3≥60 (ACR, ≥60 mg/mmol).

MAIN OUTCOMES AND MEASURES

The main outcome was time to the earliest of CKD regression or progression (sustained change in CKD stage for >3 months and ≥25% increase or decrease in eGFR from baseline or kidney failure, respectively), death, or censoring (outmigration or study end date: March 31, 2019). Cumulative incidence functions were used to estimate absolute risks, and cause-specific Cox models were used to assess the association between albuminuria and CKD regression, accounting for age, sex, eGFR, comorbidities, and health services use indicators.

RESULTS

Of 58 004 people with moderate to severe CKD (mean [SD] age, 77 [12] years; 31 725 [55%] women), 35 360 had A1 albuminuria (61%), 15 597 had A2 albuminuria (27%), 1527 had A3<60 albuminuria (3%), and 5520 had A3≥60 albuminuria (10%). Five-year probability of regression was highest with A1 (22.6%), followed by A2 (16.5%), and A3<60 (11.6%) and lowest with A3≥60 (5.3%). Using A1 albuminuria as the reference group, the hazard of regression was highest for A2 (hazard ratio [HR], 0.75; 95% CI, 0.72-0.79), then A3<60 (HR, 0.47; 95% CI, 0.40-0.54), and lowest for A3≥60 (HR, 0.27; 95% CI, 0.24-0.30).

CONCLUSIONS AND RELEVANCE

In this cohort study of people with moderate to severe CKD, albuminuria levels were inversely associated with CKD regression. These findings extend the key prognostic role of albuminuria, offering novel opportunities to discuss both favorable and adverse outcomes in people with CKD and inform CKD management.

Etiology of Persistent Microalbuminuria in Nigeria (P_MICRO study): protocol and study design

BACKGROUND

Microalbuminuria is an independent risk factor for cardiovascular and kidney disease and a predictor of end organ damage, both in the general population and in persons with HIV (PWH). Microalbuminuria is also an important risk factor for mortality in PWH treated with antiretroviral therapy (ART). In the ongoing Renal Risk Reduction (R3) study in Nigeria, we identified a high prevalence of microalbuminuria confirmed by two measurements 4-8 weeks apart in ART-experienced, virologically suppressed PWH. Although Stage 1 or 2 hypertension and exposure to potentially nephrotoxic antiretroviral medications were common in R3 participants, other traditional risk factors for albuminuria and kidney disease, including diabetes, APOL1 high-risk genotype, and smoking were rare. Co-infection with endemic pathogens may also be significant contributors to albuminuria, but co-infections were not evaluated in the R3 study population.

METHODS

In Aim 1, we will cross-sectionally compare the prevalence of albuminuria and established kidney disease risk factors in a cohort of PWH to age- and sex-matched HIV-negative adults presenting for routine care at the Aminu Kano Teaching Hospital in Kano, Nigeria. We will leverage stored specimens from 2500 R3 participants and enroll an additional 500 PLWH recently initiated on ART (≤ 24 months) and 750 age- and sex-matched HIV-negative adults to determine the contribution of HIV, hypertension, and other comorbid medical conditions to prevalent albuminuria. In Aim 2, we will follow a cohort of 1000 HIV-positive, ART-treated and 500 HIV-negative normoalbuminuric adults for 30 months to evaluate the incidence and predictors of albuminuria.

DISCUSSION

The findings from this study will support the development of interventions to prevent or address microalbuminuria in PWH to reduce kidney and cardiovascular morbidity and mortality. Such interventions might include more intensive monitoring and treatment of traditional risk factors, the provision of renin-angiotensin aldosterone system or sodium-glucose cotransporter-2 inhibitors, consideration of changes in ART regimen, and screening and treatment for relevant co-infections.

Assessment of the relationship between 25-hydroxyvitamin D and albuminuria in type 2 diabetes mellitus

BACKGROUND

Diabetic nephropathy occurs in about one-third of diabetic patients. This health problem is characterized by increased urinary albumin excretion, leading to decreased glomerular filtration rate and renal failure. In this regard, previous investigations have revealed the possibility of a relationship between vitamin D deficiency and diabetic nephropathy. The present study assessed the relationship between vitamin D deficiency and albuminuria in patients with type 2 diabetes.

METHODS

This study was conducted with 200 participants with type 2 diabetes mellitus from December 2019 to January 2021. The patients' 25-hydroxyvitamin D (25OHD) serum level and urinary albumin-to-creatinine ratio (UACR) were measured concurrently. Afterward, the subjects were divided into three groups based on their albuminuria level. Finally, 25OHD serum level and other clinical characteristics were compared among these albuminuria groups, and the relation between albuminuria level and 25OHD was analyzed.

RESULTS

The prevalence of vitamin D deficiency in macroalbuminuric patients (UACR≥300 mg/g) was 61.8%, and in microalbuminuric (30 ≤ UACR< 300 mg/g) and normoalbuminuric groups (UACR< 30 mg/g) was 33.3% and 24%, respectively. Further analysis revealed a significant negative relationship between 25OHD and albuminuria(r = - 0.257, p-value< 0.001). According to ROC curve analysis, a 25OHD level ≤ 21 ng/ml was considered an optimal cut-off point value for having macroalbuminuria in diabetic patients.

CONCLUSIONS

The current study evaluates the relation between vitamin D deficiency and the prevalence of albuminuria in the setting of diabetes. Overall, the prevalence of macroalbuminuria increased when the 25OHD serum level was less than 20 ng/ml.

Incidence rate patterns, cumulative incidence, and time trends for moderate and severe albuminuria in individuals diagnosed with type 1 diabetes aged 0-14 years: a population-based retrospective cohort study

BACKGROUND

The incidence and temporal trends of moderate and severe albuminuria during recent decades are poorly described in type 1 diabetes. We aimed to assess diabetes duration-specific incidence rates, cumulative incidence, and secular trends of albuminuria in type 1 diabetes in Finland.

METHODS

We conducted a population-based, retrospective cohort study of a stratified random sample (n=1500) of all individuals diagnosed with type 1 diabetes before age 15 years during 1970-99 in Finland. The sampling frame was the database of the Finnish Institute for Health and Welfare. Individuals with an atypical clinical course, presentation of non-diabetic kidney disease, insufficient albumin excretion rate measurements, or unavailable medical records were excluded (final sample n=1430). Study participants were followed up until death, the event of interest (moderate or severe albuminuria or kidney failure), or the most recent event-free date. Medical records retrieved up to Dec 31, 2020 were systematically reviewed for albuminuria determinations. Moderate and severe albuminuria were categorised on the basis of international reference limits (two of three consecutive urine samples). Kidney failure was defined as dialysis treatment or kidney transplant. Cohorts defined by calendar year of diabetes diagnosis (1970-79, 1980-89, and 1990-99) were assessed. Patterns of duration-specific incidences were evaluated by fitting generalised additive models to the data, which were split into multiple observations of half-year duration. Cumulative incidences were calculated with Kaplan-Meier analysis. In analyses with kidney failure as the endpoint, competing risk for mortality was incorporated.

FINDINGS

In our stratified random sample, 462 individuals were diagnosed with diabetes in 1970-79, 481 were diagnosed in 1980-89, and 487 were diagnosed in 1990-99. The incidence rate pattern of severe albuminuria changed over time; a peak at 15-19 years since diabetes onset in the 1970-79 cohort was not replicated in those diagnosed later. In the combined 1980-99 diagnosis-year cohorts, the incidence rate rose during the first 14 years after diabetes onset, after which it levelled off to a plateau. Between the 1970-79 and 1980-89 diabetes diagnosis cohorts, the cumulative incidence of severe albuminuria had approximately halved (hazard ratio [HR] 0·55 [95% CI 0·42-0·72] with the 1970-79 cohort as reference, p<0·0001), whereas, between the 1980-89 and 1990-99 cohorts, no further decrease was observed (HR 0·83 [0·54-1·26] with the 1980-89 cohort as reference, p=0·38). The 25-year cumulative incidence for severe albuminuria was 26·8% (22·6-30·8) in the 1970-79 diagnosis cohort, 12·0% (9·0-15·0) in the 1980-89 cohort, and 10·8% (6·7-14·6) in the 1990-99 cohort. 15 years after onset of severe albuminuria, cumulative progression rate from severe albuminuria to kidney failure was 35·2% (27·4-43·0) in the 1970-79 cohort and 35·6% (24·3-47·0) in the 1980-99 cohorts combined (Gray's test p=0·37). In the cohorts with data on moderate albuminuria (1980-89 and 1990-99), cumulative incidence of moderate albuminuria showed no calendar effect between the earlier and later cohorts (HR 0·99 [0·78-1·28] with the 1980-89 cohort as reference, p=0·97). The incidence rate of moderate albuminuria increased until 10 years after diabetes onset, then remained mostly stable until starting to decrease at around 25 years after diabetes onset.

INTERPRETATION

Our analyses show that the cumulative incidence of severe albuminuria has decreased between 1970-79 and 1980-99; however, whether this decrease solely denotes a delay in albuminuria, or also a true prevention of albuminuria, needs to be investigated further. Nevertheless, diabetic kidney disease remains a significant complication of type 1 diabetes. Due to the robust association of diabetic kidney disease with premature mortality, novel therapies to improve prognosis are needed.

FUNDING

Folkhälsan Research Foundation, Medical Society of Finland, Wilhelm and Else Stockmann Foundation, Finnish Diabetes Research Foundation, Waldemar von Frenckell Foundation, Liv och Hälsa Society, Academy of Finland, and Novo Nordisk Foundation.

TRANSLATIONS

For the Finnish and Swedish translations of the abstract see Supplementary Materials section.

Making an impact on kidney disease in people with type 2 diabetes: the importance of screening for albuminuria

Albuminuria is useful for early screening and diagnosis of kidney impairment, especially in people with pre-diabetes or type 2 diabetes (T2D), which is the leading cause of chronic kidney disease (CKD) and end-stage kidney disease (ESKD), associated with increased mortality, poor cardiovascular outcomes, and high economic burden. Identifying patients with CKD who are most likely to progress to ESKD permits timely implementation of appropriate interventions. The early stages of CKD are asymptomatic, which means identification of CKD relies on routine assessment of kidney damage and function. Both albuminuria and estimated glomerular filtration rate are measures of kidney function. This review discusses albuminuria as a marker of kidney damage and cardiorenal risk, highlights the importance of early screening and routine testing for albuminuria in people with T2D, and provides new insights on the optimum management of CKD in T2D using albuminuria as a target in a proposed algorithm. Elevated urine albumin can be used to detect CKD in people with T2D and monitor its progression; however, obstacles preventing early detection exist, including lack of awareness of CKD in the general population, poor adherence to clinical guidelines, and country-level variations in screening and treatment incentives. With albuminuria being used as an entry criterion and a surrogate endpoint for kidney failure in clinical trials, and with novel treatment interventions available to prevent CKD progression, there is an urgent need for early screening and diagnosis of kidney function decline in people with T2D or pre-diabetes.

Association of Mitochondrial DNA Copy Number with Risk of Progression of Kidney Disease

BACKGROUND AND OBJECTIVES

Mitochondrial DNA copy number is a biomarker of mitochondrial function, which has been hypothesized to contribute to pathogenesis of CKD through podocyte injury, tubular epithelial cell damage, and endothelial dysfunction. The prospective association of mitochondrial DNA copy number with CKD progression has not been previously evaluated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Chronic Renal Insufficiency Cohort study participants had serum levels of mitochondrial DNA copy number calculated from probe intensities of mitochondrial single nucleotide polymorphisms genotyped on the Illumina HumanOmni 1-Quad Array. CKD progression was defined as kidney failure or halving of eGFR from baseline. Cox proportional hazards models were used to calculate hazard ratios for mitochondrial DNA copy number and risk of CKD progression.

RESULTS

Among 2943 participants, mean age was 58 years, 45% were women, and 48% self-identified as Black. There were 1077 patients who experienced CKD progression over a median follow-up of 6.5 years. The incidence rate of CKD progression was highest for those in the lowest tertile of mitochondrial DNA copy number (tertile 1, 58.1; tertile 2, 50.8; tertile 3, 46.3 per 1000 person-years). Risk for CKD progression was higher for participants with lower levels of mitochondrial DNA copy number after adjustment for established risk factors (for tertile 1 versus 3, hazard ratio, 1.28 [95% confidence interval, 1.10 to 1.50]; for tertile 2 versus 3, hazard ratio, 0.99 [95% confidence interval, 0.85 to 1.16]; trend P=0.002). Similar results were seen among those with albuminuria (for tertile 1 versus 3, hazard ratio, 1.24; 95% confidence interval, 1.05 to 1.47), but there were no statistically significant associations among individuals without albuminuria (for tertile 1 versus 3, hazard ratio, 1.04; 95% confidence interval, 0.70 to 1.53; interaction P<0.001).

CONCLUSIONS

These findings suggest lower mitochondrial DNA copy number is associated with higher risk of CKD progression, independent of established risk factors among patients with CKD.

Vitamin D status in relation to inflammatory risk and albuminuria associated with polycyclic aromatic hydrocarbon exposure in the US population

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with both systematic inflammation and renal dysfunction. Reports have suggested that anti-inflammatory properties of vitamin D may provide protection against renal injury. This cross-sectional study tested the hypothesis that serum 25-hydroxyvitamin D [25(OH)D] moderates the inflammation and albuminuria associated with PAH exposure. Data were obtained from 5,982 subjects aged 20-79 years in the National Health and Nutrition Examination Survey (2001-2010). PAH exposure was estimated by urinary PAH metabolites. Inflammation was defined as serum C-reactive protein (CRP) > 3 mg/L and albuminuria as urinary albumin-to-creatinine ratio > 30 mg/g. The results found that greater PAH exposure was linked with inflammation and albuminuria. Individuals with PAH exposure also tended to have lower 25(OH)D and lower vitamin D was associated with both elevated CRP (Odds ratio [OR] = 1.28, 95% confidence interval [CI] = 1.07-1.54) and urinary albumin (1.35, 95%CI = 1.03-1.77) for any given PAH exposure. Those with lower serum 25(OH)D-to-urinary PAH ratios were likewise at a greater risk of elevated CRP and albuminuria. The findings support prior suggestions that exposure to PAHs is associated with inflammation and albuminuria but suggests further that the risk is higher when vitamin D is lower. Thus, nutritional status becomes an important variable in PAH risk assessment.

Association of Uric Acid-Lowering Therapy With Incident Chronic Kidney Disease

IMPORTANCE

Uric acid is a waste metabolite produced from the breakdown of purines, and elevated serum uric acid levels are associated with higher risk of hypertension, cardiovascular disease, and mortality and progression of chronic kidney disease (CKD). Treatment of hyperuricemia in patients with preexisting CKD has not been shown to improve kidney outcomes, but the associations of uric acid-lowering therapies with the development of new-onset kidney disease in patients with estimated glomerular filtration rate (eGFR) within reference range and no albuminuria is unclear.

OBJECTIVE

To examine the association of initiating uric acid-lowering therapy with the incidence of CKD.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients with eGFR of 60 mL/min/1.73 m2 or greater and no albuminuria treated at US Department of Veterans Affairs health care facilities from 2004 to 2019. Clinical trial emulation methods, including propensity score weighting, were used to minimize confounding. Data were analyzed from 2020 to 2022.

EXPOSURE

Newly started uric acid-lowering therapy.

MAIN OUTCOMES AND MEASURES

The main outcomes were incidences of eGFR less than 60 mL/min/1.73 m2, new-onset albuminuria, and end-stage kidney disease.

RESULTS

A total of 269 651 patients were assessed (mean [SD] age, 57.4 [12.5] years; 252 171 [94%] men). Among these, 29 501 patients (10.9%) started uric acid-lowering therapy, and 240 150 patients (89.1%) did not. Baseline characteristics, including serum uric acid level, were similar among treated and untreated patients after propensity score weighting. In the overall cohort, uric acid-lowering therapy was associated with higher risk of both incident eGFR less than 60 mL/min/1.73 m2 (weighted subhazard ratio [SHR], 1.15 [95% CI, 1.10-1.20; P < .001) and incident albuminuria (SHR, 1.05 [95% CI, 1.01-1.09; P < .001) but was not associated with the risk of end-stage kidney disease (SHR, 0.96 [95% CI, 0.62-1.50]; P = .87). In subgroup analyses, the association of uric acid-lowering therapy with worse kidney outcomes was limited to patients with baseline serum uric acid levels of 8 mg/dL or less.

CONCLUSIONS AND RELEVANCE

These findings suggest that in patients with kidney function within reference range, uric acid-lowering therapy was not associated with beneficial kidney outcomes and may be associated with potential harm in patients with less severely elevated serum uric acid levels.

Associations of Long-Term Visit-to-Visit Blood Pressure Variability With Subclinical Kidney Damage and Albuminuria in Adulthood: a 30-Year Prospective Cohort Study

BACKGROUND

Recent evidence indicates that long-term visit-to-visit blood pressure variability (BPV) may be associated with risk of cardiovascular disease. We, therefore, aimed to determine the potential associations of long-term BPV from childhood to middle age with subclinical kidney damage (SKD) and albuminuria in adulthood.

METHODS

Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, which recruited children and adolescents aged 6 to 18 years at baseline, we assessed BPV by SD and average real variability (ARV) for 30 years (6 visits). Presence of SKD was defined as estimated glomerular filtration rate between 30 and 60 mL/min per 1.73 m² or elevated urinary albumin-to creatinine ratio at least 30 mg/g. Albuminuria was defined as urinary albumin-to creatinine ratio ≥30 mg/g.

RESULTS

During 30 years of follow-up, of the 1771 participants, 204 SKD events occurred. After adjustment for demographic, clinical characteristics, and mean BP during 30 years, higher SD_SBP , ARV_SBP , SD_DBP , ARV_DBP , SD_MAP , ARV_MAP , and ARV_PP were significantly associated with higher risk of SKD. When we used cumulative exposure to BP from childhood to adulthood instead of mean BP as adjustment factors, results were similar. In addition, greater long-term BPV was also associated with the risk of albuminuria. Long-term BPV from childhood to middle age was associated with higher risk of SKD and albuminuria in adulthood, independent of mean BP or cumulative exposure to BP during follow-up.

CONCLUSIONS

Identifying long-term BPV from early age may assist in predicting kidney disease and cardiovascular disease in later life.

Risk factors for nephropathy in persons with type 1 diabetes: a population-based study

AIMS

Albuminuria is strongly associated with risk of renal dysfunction, cardiovascular disease and mortality. However, clinical guidelines diverge, and evidence is sparse on what risk factor levels regarding blood pressure, blood lipids and BMI are needed to prevent albuminuria in adolescents and young adults with type 1 diabetes.

METHODS

A total of 9347 children and adults with type 1 diabetes [mean age 15.3 years and mean diabetes duration 1.4 years at start of follow-up] from The Swedish National Diabetes Registry were followed from first registration until end of 2017. Levels for risk factors for a risk increase in nephropathy were evaluated, and the gradient of risk per 1 SD (standard deviation) was estimated to compare the impact of each risk factor.

RESULTS

During the follow-up period, 8610 (92.1%) remained normoalbuminuric, 737 (7.9%) individuals developed micro- or macroalbuminuria at any time period of whom 132 (17.9% of 737) individuals developed macroalbuminuria. Blood pressure ≥ 140/80 mmHg was associated with increased risk of albuminuria (p ≤ 0.0001), as were triglycerides ≥ 1.0 mmol/L (p = 0.039), total cholesterol ≥ 5.0 mmol/L (p =  0.0003), HDL < 1.0 mmol/L (p = 0.013), LDL 3.5- < 4.0 mmol/L (p = 0.020), and BMI ≥ 30 kg/m² (p =  0.033). HbA1c was the strongest risk factor for any albuminuria estimated by the measure gradient of risk per 1 SD, followed by diastolic blood pressure, triglycerides, systolic blood pressure, cholesterol and LDL. In patients with HbA1c > 65 mmol/mol (> 8.1%), blood pressure > 140/70 mmHg was associated with increased risk of albuminuria.

CONCLUSIONS

Preventing renal complications in adolescents and young adults with type 1 diabetes need avoidance at relatively high levels of blood pressure, blood lipids and BMI, whereas very tight control is not associated with further risk reduction. For patients with long-term poor glycaemic control, stricter blood pressure control is advocated.

Association of the Atherogenic Index of Plasma with C-Reactive Protein and Urinary Albumin Excretion in a Normotensive Nondiabetic Population

Background: The atherogenic index of plasma (AIP) is an indicator of atherogenic dyslipidemia and is significantly associated with the development of atherosclerotic cardiovascular disease. Previous studies showing the association of AIP with C-reactive protein (CRP) and microalbuminuria included hypertensive and diabetic patients. We aimed to determine the association of AIP with CRP and albuminuria in a normotensive and nondiabetic population. Methods: The study was conducted retrospectively. Two hundred thirty-three individuals without hypertension, diabetes, cardiovascular disease, malignancy, systemic inflammatory disease, nephrological disease, and active infection were determined and included in the study. Urinary albumin excretion was calculated from the albumin-creatinine ratio in fresh spot urine [urinary albumin-creatinine ratio (UACR)]. AIP risk groups were compared in terms of clinical and laboratory findings, and the correlation between AIP and CRP and UACR was evaluated. Results: A total of 233 people, with a mean age of 45.4 years and 139 (69.7%) of whom were male, were included in the study. One hundred thirty-eight (59.2%) individuals were found to be in the low-risk group, 29 (12.5%) in the medium-risk group, and 66 (28.3%) in the high-risk group, according to the AIP value. CRP and UACR were not different between the AIP risk groups (P: 0.141 and 0.441, respectively). A mild correlation was found between AIP and CRP (r: 0.192; P: 0.003), but no correlation was found between AIP and UACR (r: 0.086; P: 0.193). The stepwise linear regression analysis with model adjusted for possible confounders and AIP revealed that only body mass index was a significant predictor of CRP (β: 0.308; P < 0.001), while only systolic blood pressure was a significant predictor of UACR (β: 0.19; P: 0.004), but AIP was not. Conclusions: AIP was not associated with CRP and UACR in normotensive and nondiabetic individuals. This finding suggests that the relationship found in previous studies is related to the presence of hypertension or diabetes rather than the AIP.

Microalbuminuria Constitutes a Clinical Action Item for Clinicians in 2021

Chronic kidney disease affects approximately 10% of the population or 800 million people globally, with diabetes being the leading cause. The presence of chronic kidney disease with impaired kidney function or with albuminuria is associated with an increased risk of a progressive loss of renal function and increased risk of cardiovascular disease and excess mortality. Screening for chronic kidney disease is critically important because during the initial stages patients often have no symptoms and because we now have available recently approved multiple interventions that can reduce the high risks dramatically. Screening should be performed with regular measurement of albumin in the urine and creatinine or cystatin C in blood for estimation of kidney function. Regretfully recent data indicates that screening for albuminuria is conducted in only 20%-50% of people at risk depending on the setting. Clinicians need to perform regular screening and concomitant management of risk factors. Recent therapeutic options must be implemented to improve outcomes. Finally, a reduction in albuminuria after initiation of intervention constitutes a treatment target because it indicates improved prognosis.

Glomerular filtration rate as a kidney outcome of diabetic kidney disease: a focus on new antidiabetic drugs

Diabetes has reached epidemic proportions, both in Korea and worldwide and is associated with an increased risk of chronic kidney disease and kidney failure (KF). The natural course of kidney function among people with diabetes (especially type 2 diabetes) may be complex in real-world situations. Strong evidence from observational data and clinical trials has demonstrated a consistent association between decreased estimated glomerular filtration rate (eGFR) and subsequent development of hard renal endpoints (such as KF or renal death). The disadvantage of hard renal endpoints is that they require a long follow-up duration. In addition, there are many patients with diabetes whose renal function declines without the appearance of albuminuria, measurement of the eGFR is emphasized. Many studies have used GFR-related parameters, such as its change, decline, or slope, as clinical endpoints for kidney disease progression. In this respect, understanding the trends in GFR changes could be crucial for developing clinical management strategies for the prevention of diabetic complications. This review focuses on the clinical implication of the eGFR-related parameters that have been used so far in diabetic kidney disease. We also discuss the use of recently developed new antidiabetic drugs for kidney protection, with a focus on the GFR as clinical endpoints.