Chapter 2: Definition, identification, and prediction of CKD progression

The utility of serum neutrophil gelatinase-associated lipocalin level on predicting autosomal dominant polycystic kidney disease progression

INTRODUCTION

We focused on neutrophil gelatinase-associated lipocalin (NGAL) and autosomal dominant polycystic kidney disease (ADPKD) progression.

METHODS

ADPKD patients with an estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2 were included. Serum NGAL level and NGAL to eGFR ratio (NGR), height-adjusted total kidney volume (hTKV) were assessed initially. Patients were followed-up for 5 years.

RESULTS

Sixty one patients were enrolled and initial eGFR was 73.6 (48.9-101.5) ml/min/1.73m2. EGFR declined by 3.7 mL/min/1.73m2 per year. Thirty four patients (55.7%) exhibited rapid progression. Rapid progression group had lower serum NGAL levels (p < 0.001) and higher hTKV (p < 0.001). Lower serum NGAL level was a risk factor for rapid progression (p < 0.001). NGR was not associated with rapid progression. Serum NGAL level was predictive in for rapid progression ROC analysis (cut-off <10.62 ng/mL).

CONCLUSION

Relatively lower serum NGAL levels can predict worse outcomes in ADPKD and can provide risk stratification in patients with ADPKD.

Prevalence and Risk Factors of Chronic Kidney Disease in Patients With Type 2 Diabetes in China: Cross-Sectional Study

BACKGROUND

Chronic kidney disease (CKD) is a significant long-term complication of diabetes and is a primary contributor to end-stage kidney disease.

OBJECTIVE

This study aimed to report comprehensive nationwide data on the prevalence, screening, and awareness rates of CKD in Chinese patients with type 2 diabetes, along with associated risk factors.

METHODS

Baseline data analysis of the ongoing prospective, observational IMPROVE study was conducted. The study cohort comprised patients who had been diagnosed with type 2 diabetes more than 12 months prior, received at least 1 hypoglycemic medication, and were aged ≥18 years. The participants completed questionnaires and underwent laboratory assessments, including blood and urine samples. The data encompassed patient demographics, medical history, concurrent medications, and comorbidities. Comprehensive evaluations involved physical examinations, urinary albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), glycated hemoglobin (HbA1c), fasting blood glucose, 2-hour postprandial blood glucose, fasting blood lipid profile, and urinalysis. Descriptive statistics were applied for data interpretation, and logistic regression analyses were used to identify the CKD-associated risk factors in patients with type 2 diabetes.

RESULTS

A national study from December 2021 to September 2022 enlisted 9672 participants with type 2 diabetes from 45 hospitals that had endocrinology departments. The enrollees were from diverse regions in China, as follows: central (n=1221), east (n=3269), south (n=1474), north (n=2219), and west (n=1489). The prevalence, screening, and awareness rates of CKD among patients with type 2 diabetes were 31% (2997/9672), 27% (810/2997), and 54.8% (5295/9672), respectively. Multivariate binary regression analysis revealed that the CKD risk factors were screening, awareness, smoking, age, diabetes duration, concurrent antihypertensive and microcirculation medications, diabetic complications (foot, retinopathy, and neuropathy), hypertension, elevated low-density lipoprotein (LDL) cholesterol, and suboptimal glycemic control. Subgroup analysis highlighted an increased CKD prevalence among older individuals, those with prolonged diabetes durations, and residents of fourth-tier cities. Residents of urban areas that had robust educational and economic development exhibited relatively high awareness and screening rates. Notably, 24.2% (1717/7107) of patients with an eGFR ≥90 mL/min/1.73 m2 had proteinuria, whereas 3.4% (234/6909) who had a UACR <30 mg/g presented with an eGFR <60 mL/min/1.73 m2. Compared with patients who were cognizant of CKD, those who were unaware of CKD had increased rates of HbA1c ≥7%, total cholesterol >5.18 μmol/L, LDL cholesterol >3.37 μmol/L, BMI ≥30 kg/m2, and hypertension.

CONCLUSIONS

In a Chinese population of adults with type 2 diabetes, the CKD prevalence was notable, at 31%, coupled with low screening and awareness rates. Multiple risk factors for CKD have been identified.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05047471; https://clinicaltrials.gov/study/NCT05047471.

Diagnostic performance of an albuminuria point-of-care test in screening for chronic kidney disease among young people living with HIV in Uganda: a cross-sectional study

OBJECTIVES

The main aim was to determine the diagnostic performance of an albuminuria point-of-care test (POC) for diagnosis of chronic kidney disease among young people living with HIV (YPLHIV) in Uganda.

DESIGN

We conducted a cross-sectional study comparing the diagnostic performance of MicroalbuPHAN (Erba Lachema, Czech Republic), an albuminuria POC test against the laboratory-measured albumin and creatinine as the reference standard.

SETTING

The study was set in seven HIV clinics in Kampala, Uganda that provide antiretroviral therapy to adults and children living with HIV. The study took place from April to August 2023.

PARTICIPANTS

497 YPLHIV aged 10-24 years who were diagnosed with HIV before 10 years of age were randomly selected from the HIV clinics. Pregnant YPLHIV were excluded.

PROCEDURES

Participants provided a spot urine sample that was tested for albumin and creatinine using the POC and in the laboratory and proteinuria using urine dipstick. The sensitivity, specificity, negative and positive predictive values (NPV, PPV) of the POC versus the laboratory test were calculated, and factors associated with having a positive POC test were estimated using logistic regression.

OUTCOME MEASURES

The primary outcome was a diagnosis of albuminuria defined as an albumin creatinine ratio above 30 mg/g.

RESULTS

Of the 497 participants enrolled, 278 (55.9%) were female and 331 (66.8%) were aged 10-17 years. The POC test had a sensitivity of 74.5% (95% CI 70.6% to 78.4%) and specificity of 68.1% (95% CI 63.9% to 72.3%). The PPV was 21.5% (95% CI 17.8% to 25.1%) and the NPV was 95.8% (95% CI 94.0% to 97.6%), with an accuracy of 68.8%. There was strong evidence that a positive POC test was associated with having proteinuria (OR 2.82; 95% CI 1.89 to 4.22, p<0.001); body mass index <19.5 (OR 1.69 95% CI 1.17 to 2.45, p=0.005) and being male (OR 1.48; 95% CI 1.02 to 2.14, p=0.04).

CONCLUSIONS

The albuminuria POC test had low sensitivity and specificity. However, it can be used to exclude kidney disease given its high NPV. It should be validated against the 24-hour urinary excretion rate to further determine its diagnostic performance.

Urinary vanin-1 as a novel biomarker for survival in peripheral artery disease

BACKGROUND

Chronic kidney disease is associated with increased rates of incidence, morbidity, and mortality in lower-extremity peripheral artery disease (PAD). No specific marker for a functional risk assessment of kidney disease in PAD is known, especially at the early stages. Thus, we speculated that urinary vanin-1 (uVNN1), a marker of oxidative stress even in early kidney injury, could further stratify outcome assessment in patients with PAD.

METHODS

Patients with stable PAD (n = 304) of the Vienna medical cohort were followed up for up to 10 years and the outcome was assessed by central death database queries. uVNN1 was measured by enzyme-linked immunosorbent assay (ELISA) at study inclusion and normalized to urinary creatinine (uVNN1/Cr). During the observation time (9.3, 7.0-9.8 years), 104 patients died, 54.8% of which were due to cardiovascular causes.

RESULTS

uVNN1/Cr was associated with a urine albumin-creatinine ratio (UACR) (R = 0.166, p = 0.004) but not with an estimated glomerular filtration rate (R = 0.102, p = 0.077). Levels of uVNN1/Cr did not differ between asymptomatic and symptomatic PAD (p = 0.406). Kaplan-Meier curves showed a clear-cut association with higher all-cause (log-rank p = 0.034) and cardiovascular mortality (log-rank p = 0.032) with higher uVNN1/Cr levels. Similarly, significant associations for all-cause (hazard ratio [HR] 1.34, 95% CI [1.08-1.67], p = 0.009) and cardiovascular mortality (HR 1.45, 95% CI [1.06-1.99], p = 0.020) could be seen in multivariable Cox regression models.

CONCLUSIONS

uVNN1/Cr showed an independent association with both all-cause and cardiovascular mortality in patients with PAD and was associated with early kidney disease. Thus, uVNN1 could be a useful marker for risk stratification of kidney disease in PAD.

Estimated Glomerular Filtration Rate Slope as an Endpoint in Cardiovascular Trials

PURPOSE OF REVIEW

End stage kidney disease can be a slow process and it may be challenging to achieve required follow-up for sufficient events. Therefore, a surrogate kidney endpoint, such as estimated glomerular filtration rate (eGFR) slope maybe attractive to assess the kidney in cardiovascular trials, especially heart failure (HF).

RECENT FINDINGS

eGFR slope can generate informative results in a shorter follow-up period, has decreased risk of type-2 error, and is less sensitive to eGFR shifts compared with other surrogate kidney endpoints (eGFR decline≥40% or doubling creatinine). However, eGFR slope has its limitations with acute effects, heterogeneity in slope calculation/reporting, and deviations from linearity. eGFR slope is a kidney endpoint which may be well-suited for HF trials. Cross-collaborated guideline recommendations are needed to optimize the use of eGFR slope as a kidney endpoint in patients with HF.

Long-term renal outcome of Cryopyrin-associated periodic syndrome (CAPS) under anti-Interleukin-1 therapy

Cryopyrin-associated periodic syndromes (CAPS) are orphan hereditary auto-inflammatory diseases with various phenotypes, including chronic kidney disease (CKD). Current therapies inhibit interleukin-1 (IL-1) to achieve clinical and serological remission; however, the effect on kidney involvement remains unclear. The objective of this study was to investigate the long-term efficacy of anti-IL-1 treatment with special emphasis on renal outcome. We retrospectively analysed clinical, genetic and laboratory data of patients with CAPS under anti-IL-1 therapy from a single-centre university outpatient clinic. Patients with CAPS (n = 28) were followed for a median of 11 (IQR 8.5-13) years. Four patients at various ages (19%), bearing the most common CAPS mutation R260W, had significant CKD at presentation. All affected patients were related; however, other family members with the same genetic variant did not develop CKD. While anti-IL-1 therapy was effective in lowering symptom burden and inflammatory parameters in all CAPS patients, two of the four individuals with significant CKD had persistent proteinuria and worsening kidney function. None of the patients without renal affection at therapy initiation developed relevant CKD in the follow-up period. We showed that in patients with CAPS: (1) CKD is a common complication; (2) renal involvement shows familial predisposition beyond the mutational status and is independent of age; (3) anti-IL-1 therapy results in sustained improvement of inflammatory parameters and symptom load and (4) may prevent development of CAPS-associated CKD but not affect kidney involvement when already present. Overall, early therapy initiation might sufficiently prevent renal disease manifestation and attenuate progression.

Association of plasma ceramide with decline in kidney function in patients with type 2 diabetes

Circulating ceramide levels are dysregulated in kidney disease. However, their associations with rapid decline in kidney function (RDKF) and end-stage kidney disease (ESKD) in patients with type 2 diabetes (T2D) are unknown. In this prospective study of 1746 T2D participants, we examined the association of plasma ceramide Cer16:0, Cer18:0, Cer24:0, and Cer24:1 with RDKF, defined as an estimated glomerular filtration rate (eGFR) decline of 5 ml/min/1.73 m2 per year or greater, and ESKD defined as eGFR <15/min/1.73 m2 for at least 3 months, on dialysis or renal death at follow-up. During a median follow-up period of 7.7 years, 197 patients experienced RDKF. Ceramide Cer24:0 (odds ratio [OR] = 0.71, 95% CI 0.56-0.90) and ratios Cer16:0/Cer24:0 (OR = 3.54 [1.70-7.35]), Cer18:0/Cer24:0 (OR = 1.89 [1.10-3.25]), and Cer24:1/Cer24:0 (OR = 4.01 [1.93-8.31]) significantly associated with RDKF in multivariable analysis; 124 patients developed ESKD. The ratios Cer16:0/Cer24:0 (hazard ratio [HR] = 3.10 [1.44-6.64]) and Cer24:1/Cer24:0 (HR = 4.66 [1.93-11.24]) significantly associated with a higher risk of ESKD. The Cer24:1/Cer24:0 ratio improved risk discrimination for ESKD beyond traditional risk factors by small but statistically significant margin (Harrell C-index difference: 0.01; P = 0.022). A high ceramide risk score also associated with RDKF (OR = 2.28 [1.26-4.13]) compared to lower risk score. In conclusion, specific ceramide levels and their ratios are associated with RDKF and conferred an increased risk of ESKD, independently of traditional risk factors, including baseline renal functions in patients with T2D.

Galectin-3 in chronic kidney disease

BACKGROUND AND AIMS

High serum galectin-3 has been associated with adverse outcomes among dialysis patients, although its prognostic role remains unclear among individuals with earlier-stage chronic kidney disease. The present systematic review aims to evaluate the association of serum galectin-3 with survival, cardiovascular disease and kidney disease progression among non-dialysis chronic kidney disease patients.

METHODS

PubMed, Scopus, Web of Science, CENTRAL and Google Scholar were systematically searched till November 10, 2023. All observational studies assessing the prognostic role of serum galectin-3 in patients with non-dialysis chronic kidney disease were included.

RESULTS

Overall, 12 studies (10 cohort, 2 cross-sectional) were included, comprising 9,349 patients. The endpoint of survival was assessed in 5 studies, indicating a significant association between increasing serum galectin-3 levels and higher all-cause mortality risk (Hazard ratio per unit: 1.22, 95 % confidence intervals-CI: 1.05-1.41, ≥6 ng/mL: 2.66, 95 % CI: 1.68-4.23). Current evidence coming from 4 studies was inconclusive regarding the potential link of galectin-3 and kidney function decline, yielding conflicting results. No significant associations between serum galectin-3 and heart failure, cardiovascular events or death were consistently reported.

CONCLUSIONS

This systematic review supports the prognostic role of galectin-3 in chronic kidney disease, as its increased serum values may be associated with higher all-cause mortality risk. No clear role could be supported for serum galectin-3 regarding the prediction of cardiovascular disease or kidney disease progression.

Slope of the estimated glomerular filtration rate and its associated factors among individuals with chronic kidney disease in the general Japanese population

BACKGROUND

To suppress the incidence of end-stage kidney disease, we need to identify chronic kidney disease (CKD) patients with a high risk of rapid decline in the estimated glomerular filtration rate (eGFR). However, the current status of eGFR slope and its associated factors in the Japanese population have not been fully elucidated.

METHODS

Among examinees aged 40-70 years in the 2014 Specific Health Checkup conducted by the National Health Insurance in Kobe, Japan (n = 61,985), we prospectively observed 7291 examinees with CKD stage G3 from 2014 to 2018.

RESULTS

Until 2018, 4221 examinees continued to undergo annual SHCs for a total of five checkups per subject and had available records of all necessary data. The median eGFR change was -0.22 ml/min/1.73 m2/year. Only 9.2% of those subjects showed rapid eGFR decline (faster than -2.0 ml/min/1.73 m2/year). Logistic regression analysis identified diabetes, smoking habits, high urinary protein levels, older age, high systolic blood pressure, and low serum low-density lipoprotein cholesterol levels as independent predictors for rapid eGFR decline. Hemoglobin A1c levels did not contribute to the eGFR slope in CKD stage-G3 subjects with diabetes and proteinuria.

CONCLUSION

Most Japanese CKD stage-G3 subjects had a very slow decline in eGFR. A small proportion of CKD individuals who have a predictive factor of rapid eGFR decline should receive considerable attention from a nephrologist.

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

Within and post-trial effects of an intensive lifestyle intervention on kidney disease in adults with overweight or obesity and type 2 diabetes mellitus: a secondary analysis of the Look AHEAD clinical trial

INTRODUCTION

The Look AHEAD randomized clinical trial reported that an 8-year intensive lifestyle intervention (ILI) compared with diabetes support and education (DSE) in adults aged 45-76 years with type 2 diabetes and overweight/obesity delayed kidney disease progression. Here, we report long-term post-intervention follow-up for the trial's secondary outcome of kidney disease.

RESEARCH DESIGN AND METHODS

We examined effects of ILI (n=2570) versus DSE (n=2575) on decline in estimated glomerular filtration rate (eGFR) to <45 mL/min/1.73 m2 or need for kidney replacement therapy (KRT: dialysis or kidney transplant) during intervention and post-intervention follow-up (median 15.6 years overall).

RESULTS

Incidence of eGFR <45 mL/min/1.73 m2 was lower in ILI during the intervention (HR=0.80, 95% CI=0.66 to 0.98) but not post-intervention (HR=1.03, 0.86 to 1.23) or overall (HR=0.92, 0.80 to 1.04). There were no significant treatment group differences in KRT. In prespecified subgroup analyses, age×treatment interactions were significant over total follow-up: p=0.001 for eGFR <45 mL/min/1.73 m2 and p=0.01 for KRT. The 2205 participants aged >60 years at baseline had benefit in both kidney outcomes during intervention and overall (HR=0.75, 0.62 to 0.90 for eGFR <45 mL/min/1.73 m2; HR=0.62, 0.43 to 0.91 for KRT). The absolute treatment effects were greater post-intervention: ILI reduced the rate of eGFR <45 mL/min/1.73 m2 by 0.46 and 0.76 cases/100 person-years during and post-intervention, respectively; and reduced KRT by 0.15 and 0.21 cases/100 person-years. The younger participants experienced no such post-intervention benefits.

CONCLUSIONS

ILI reduced kidney disease progression during and following the active intervention in persons aged ≥60 years. ILI should be considered for reducing kidney disease incidence in older persons with type 2 diabetes.

Association of soluble suppression of tumorigenicity 2 with mortality and adverse outcomes in chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Early risk stratification is necessary to prevent chronic kidney disease progression and complications. This systematic review aims to evaluate the association of soluble suppression of tumorigenicity 2 (sST2), a member of the interleukin-1 receptor family, with all-cause mortality, cardiovascular disease and renal function deterioration among chronic kidney disease patients.

METHODS

PubMed, Scopus, Web of Science, CENTRAL and Google Scholar were systematically searched from inception to December 20, 2023. Cohort studies examining the prognostic role of sST2 levels in pre-dialysis and dialysis patients were included. In case of 3 or more studies per outcome, conventional and dose-response meta-analyses were conducted.

RESULTS

Overall, 21 studies were included comprising 15,100 patients. In pre-dialysis patients, the qualitative synthesis of studies suggested that high sST2 is associated with significantly increased all-cause mortality, while evidence regarding cardiovascular events or kidney disease progression was conflicting. In the dialysis population, high sST2 was linked to an elevated risk of all-cause (Hazard ratio-HR: 3.00, 95% confidence intervals-CI: 1.95-4.61) and cardiovascular (HR: 2.38, 95% CI: 1.69-3.34) mortality. Dose-response meta-analysis suggested a log-linear association of sST2 with both all-cause (χ2: 34.65, p value < 0.001) and cardiovascular (χ2: 29.14, p value < 0.001) mortality, whereas findings regarding cardiovascular events were limited with mixed results.

CONCLUSIONS

High sST2 values are associated with an increased risk of all-cause mortality in pre-dialysis and dialysis patients, as well as with an elevated risk of cardiovascular mortality in the dialysis population. Further studies are needed to elucidate its potential association with cardiovascular events and kidney disease progression.

Predicting chronic kidney disease progression with artificial intelligence

BACKGROUND

The use of tools that allow estimation of the probability of progression of chronic kidney disease (CKD) to advanced stages has not yet achieved significant practical importance in clinical setting. This study aimed to develop and validate a machine learning-based model for predicting the need for renal replacement therapy (RRT) and disease progression for patients with stage 3-5 CKD.

METHODS

This was a retrospective, closed cohort, observational study. Patients with CKD affiliated with a private insurer with five-year follow-up data were selected. Demographic, clinical, and laboratory variables were included, and the models were developed based on machine learning methods. The outcomes were CKD progression, a significant decrease in the estimated glomerular filtration rate (eGFR), and the need for RRT.

RESULTS

Three prediction models were developed-Model 1 (risk at 4.5 years, n = 1446) with a F1 of 0.82, 0.53, and 0.55 for RRT, stage progression, and reduction in the eGFR, respectively,- Model 2 (time- to-event, n = 2143) with a C-index of 0.89, 0.67, and 0.67 for RRT, stage progression, reduction in the eGFR, respectively, and Model 3 (reduced Model 2) with C-index = 0.68, 0.68 and 0.88, for RRT, stage progression, reduction in the eGFR, respectively.

CONCLUSION

The time-to-event model performed well in predicting the three outcomes of CKD progression at five years. This model can be useful for predicting the onset and time of occurrence of the outcomes of interest in the population with established CKD.

Association of kidney function with physical performance: the Maastricht study

BACKGROUND

Kidney failure has been associated with decreased physical capacity, although evidence regarding the physical performance of individuals with earlier stages of chronic kidney disease (CKD) remains limited.

METHODS

Cross-sectional data were derived from the prospective, population-based Maastricht Study. Multivariate linear regression models were fitted to assess the association of estimated glomerular filtration rate (eGFR) and albuminuria categories with physical performance test outcomes.

RESULTS

Overall, 7396 participants were included. Compared to eGFR 60-90 ml/min/1.73 m2, values < 60 ml/min/1.73 m2 were associated with significantly shorter 6-min walk distance (β: - 13.04 m, 95% confidence intervals-CI - 19.95; - 6.13), worse timed chair rise stand test time (β: 0.91 s, 95% CI 0.36; 1.47), lower maximal grip (β: - 0.83 kg, 95% CI - 1.50; - 0.15) and elbow flexion (β: - 3.64 Nm, 95% CI - 7.11; - 0.16) strength. Additionally, eGFR > 90 ml/min/1.73 m2 was linked to significantly shorter 6-min walk distance (β: - 6.13 m, 95% CI - 9.44; - 2.82). Urinary albumin excretion > 30 mg/24 h was associated with shorter 6-min walk distance (β: - 12.48 m, 95% CI - 18.28; - 6.68), worse timed chair rise stand test time (β: 0.51 s, 95% CI 0.11; 1.06), lower maximal grip (β: - 1.34 kg, 95% CI - 1.91; - 0.76) and elbow flexion strength (β: - 3.31 Nm, 95% CI - 5.80; - 0.82).

CONCLUSIONS

Reduced eGFR and higher albuminuria levels were associated with worse physical performance, especially shorter 6-min walk distance and lower muscle strength. The relationship between eGFR and physical function was non-linear, with also high eGFR values being associated with worse performance, especially in the six-minute walk test.

Multicentre external validation of the prognostic model kidney failure risk equation in patients with CKD stages 3 and 4 in Peru: a retrospective cohort study

OBJECTIVES

To externally validate the four-variable kidney failure risk equation (KFRE) in the Peruvian population for predicting kidney failure at 2 and 5 years.

DESIGN

A retrospective cohort study.

SETTING

17 primary care centres from the Health's Social Security of Peru.

PARTICIPANTS

Patients older than 18 years, diagnosed with chronic kidney disease stage 3a-3b-4 and 3b-4, between January 2013 and December 2017. Patients were followed until they developed kidney failure, died, were lost, or ended the study (31 December 2019), whichever came first.

PRIMARY AND SECONDARY OUTCOME MEASURES

Performance of the KFRE model was assessed based on discrimination and calibration measures considering the competing risk of death.

RESULTS

We included 7519 patients in stages 3a-4 and 2798 patients in stages 3b-4. The estimated cumulative incidence of kidney failure, accounting for competing event of death, at 2 years and 5 years, was 1.52% and 3.37% in stages 3a-4 and 3.15% and 6.86% in stages 3b-4. KFRE discrimination at 2 and 5 years was high, with time-dependent area under the curve and C-index >0.8 for all populations. Regarding calibration in-the-large, the observed to expected ratio and the calibration intercept indicated that KFRE underestimates the overall risk at 2 years and overestimates it at 5 years in all populations.

CONCLUSIONS

The four-variable KFRE models have good discrimination but poor calibration in the Peruvian population. The model underestimates the risk of kidney failure in the short term and overestimates it in the long term. Further research should focus on updating or recalibrating the KFRE model to better predict kidney failure in the Peruvian context before recommending its use in clinical practice.

Kidney function decline is associated with mortality events: over a decade of follow-up from Tehran Lipid and Glucose Study

BACKGROUND

To investigate the association between estimated glomerular filtration rate (eGFR) change and mortality risk in a cohort from the Middle East and North Africa region with increasing chronic kidney disease burden.

METHODS

We included 2210 participants aged ≥ 50 years from the prospective cohort of the Tehran Lipid and Glucose Study. The interval for eGFR measurement was between the examinations in 2002-2005 to 2009-2011, and participants were followed through March 2018. Glomerular filtration rate was estimated from serum creatinine using the CKD-EPI creatinine equation. We assessed the association of rapid kidney function decline, (defined as annual eGFR decline ≥ 3 ml/min/1.73 m2 per year); ≥ 30% eGFR decline over six years; and certain drop in kidney function (≥ 25% eGFR decline plus drop in eGFR category) with mortality outcomes.

RESULTS

During a median follow-up of 14.3 years after recruitment, 315 all-cause and 112 cardiovascular disease deaths were recorded. The multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause death for rapid kidney function decline, ≥ 30% decline in eGFR over 6 years, and drop in kidney function were 1.68 (1.24-2.27), 2.01 (1.46-2.78), and 1.49 (1.11-1.98), respectively. The HRs of all-cause death and for rapid kidney function decline in those without and with chronic kidney disease were 1.41 (1.03-1.91) and 3.38 (1.69-6.76), respectively. Similar findings were observed regarding cardiovascular disease-related and non-cardiovascular disease-related mortality.

CONCLUSIONS

Estimated GFR decline is associated with an increased mortality risk, indicating its ability to provide additional prognostic information beyond traditional risk predictors in the general population.

Older patients are less prone to fast decline of renal function: a propensity-matched study

PURPOSE

Despite CKD is common among older patients, and although factors associated with CKD progression have been explored over decades, little is known about the decline of renal function specifically in older individuals.

METHODS

We included adult patients with CKD on conservative management in a propensity-score matched study 1:1 older (> 65 year) and young (≤ 65 yr). Factors associated with the slope of the decline of eGFR such as proteinuria, initial eGFR, diabetes, sex, and use of angiotensin-converting enzyme inhibitor/angiotensin receptor block (ACEI/ARB) were analyzed. Inclusion criteria were at least two consultations in the service and an initial eGFR lower than 45 ml/min/m2, in the period between January 2012 and December 2017.

RESULTS

Crude analysis of eGFR decline shows a slower progression of older patients when compared to younger patients in both absolute change [- 2.0 (- 4.5, - 1.0) vs. -3.0 (- 7.0, - 1.0) ml/min/1.73m2, p < 0.001] and slope of eGFR reduction [- 2.2 (- 4.4, - 1.0) vs. 3.1 (- 6.7, - 1.2)) ml/min/1.73m2, p < 0.001]. Patients considered fast progressors (> 5 ml/min/1.73 m2/year decline in eGFR) were less likely to be older (35.2% young vs. 22.0% older, p < 0.001). Adjusted logistic multivariate regression confirmed that older patients had less odds ratio of eGFR decline, independently of the presence of proteinuria, diabetes, ACEI/ARB use, sex, baseline eGFR, baseline phosphate and baseline 25(OH) vitamin D.

CONCLUSION

Older patients present slower CKD progression even after multiple adjustments. This information should be taken into consideration while treating these patients on conservative management and should be kept in mind while planning dialysis start.

Geriatric Nutritional Risk Index as a Prognostic Factor for Renal Progression in Patients with Type 2 Diabetes Mellitus

The aim of this study was to evaluate whether the geriatric nutritional risk index (GNRI) is associated with chronic kidney disease (CKD) progression in patients with type 2 diabetes mellitus (DM). In total, 1100 patients with type 2 DM with a follow-up duration > 1 year were included in this longitudinal study. The risk of CKD progression was assessed according to GNRI quartiles. Patients in the lowest GNRI quartile exhibited a significantly lower estimated glomerular filtration rate (eGFR), compared with those in quartile four. Moreover, these patients had poorer glycemic control and lower hemoglobin levels, body mass index, and albumin levels. Additionally, they exhibited a greater annual decline in eGFR. Multivariate logistic regression analysis showed that old age (>60 years), baseline eGFR, the presence of proteinuria, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and low GNRI were significantly associated with CKD progression. GNRI may serve as a valuable predictive tool for identifying the risk of adverse renal outcomes in patients with type 2 DM. It may potentially serve as a more feasible measure for assessing the nutritional status of these patients, as well as for predicting their clinical outcomes.

Association of physical activity with endothelial dysfunction among adults with and without chronic kidney disease: The Maastricht Study

BACKGROUND AND AIMS

Physical activity (PA) constitutes an established protective factor while sedentary behavior (SB) an emerging independent risk factor for cardiovascular diseases. This study evaluated the association of PA and SB with endothelial dysfunction (ED) depending on kidney function status.

METHODS

Cross-sectional data from the prospective, population-based Maastricht Study were used. PA and SB were measured using the ActivPAL3 accelerometer 24h/day for eight consecutive days. ED was evaluated by plasma levels of soluble vascular cell adhesion protein-1, intercellular adhesion molecule-1, E-selectin and von Willebrand factor, which were combined into an ED score with higher values depicting higher ED.

RESULTS

Overall, 2,668 participants, 323 with chronic kidney disease, were included. In normal kidney function individuals, the ED score presented a significant negative association with total, lower-intensity and moderate-to-vigorous PA duration and a positive association with total sedentary time, sedentary breaks and sedentary bout duration. In participants with chronic kidney disease, a significant negative association of ED score with total [β: -4.42, 95% confidence intervals (95% CI): -7.98; -0.87] and lower-intensity (β: -7.08, 95% CI: -13.41; -0.74) PA duration, as well as a positive association of ED score with sedentary bout duration (β: 43.72, 95% CI: 9.85; 77.59) were noted. The strength of associations did not significantly differ across kidney function subgroups (p > 0.05).

CONCLUSIONS

This analysis showed that PA duration is inversely associated with ED both among patients with normal kidney function and chronic kidney disease. In chronic kidney disease, longer sedentary bouts were associated with greater endothelial dysfunction.

Circulating AFABP, FGF21, and PEDF Levels as Prognostic Biomarkers of Sight-threatening Diabetic Retinopathy

CONTEXT

Adipocyte fatty acid-binding protein (AFABP), fibroblast growth factor 21 (FGF21), and pigment epithelium-derived factor (PEDF) are 3 diabetes-related biomarkers whose circulating levels had been shown to associate with nephropathy progression in Chinese patients with type 2 diabetes.

OBJECTIVE

Here, we evaluated and compared their prospective associations with the development of sight-threatening DR (STDR), another important diabetic microvascular complication.

METHODS

Baseline serum AFABP, PEDF, and FGF21 levels were measured in 4760 Chinese individuals with type 2 diabetes and without STDR at baseline. The associations of these biomarkers with incident STDR were analyzed using Cox regression analysis.

RESULTS

Among these 4760 participants (mean diabetes duration of 11 years and ≥ 50% with nonproliferative DR at baseline), 172 participants developed STDR over a median follow-up of 8.8 years. Participants with incident STDR had comparable baseline serum FGF21 levels but significantly higher baseline serum AFABP and PEDF levels (both P < .001) than those without. However, in multivariable Cox regression analysis, only serum AFABP remained independently associated with incident STDR (hazard ratio 1.28; 95% CI, 1.05-1.55; P = .013). The addition of serum AFABP to a clinical model of conventional STDR risk factors including diabetes duration, glycemic control, albuminuria, and baseline DR status significantly improved the c statistics (P < .001), net reclassification index (P = .0027), and integrated discrimination index (P = .033) in predicting incident STDR among participants without DR or with mild DR at baseline.

CONCLUSION

Among the 3 diabetes-related biomarkers, serum AFABP level appeared to be a more clinically useful biomarker for predicting incident STDR in type 2 diabetes.

Low glomerular filtration rate values are associated with higher TSH in an elderly population at high cardiovascular disease risk

Background

Hypothyroidism is associated with impaired glomerular filtration rate (GFR), a recognized cardiovascular disease (CVD), and mortality risk factor. In older adults, this association remains unexplored. We aimed to determine the relationship of elevated TSH with GFR in an elderly population at high CVD risk.

Methods

Older adults (age>65ys) with high CVD risk defined by two or more CVD risk factors: smoking (S), high blood pressure (HBP), high total cholesterol, low HDL cholesterol, diabetes (DM), metabolic syndrome or previous cardiovascular event, were prospectively included at our ambulatory Endocrine Clinic. Patients under levothyroxine or thyroid disease were excluded. TSH> 6mU/l defined subclinical hypothyroidism (ScH) with normal free T4 levels. Estimated GFR was calculated by the Berlin-Initiative Study (BIS)-1 formula for elderly population. Urinary albumin to creatinine ratio (uACR), IL-6 and TNF-α, and Carotid intima-media thickness (CIMT) were also determined. The U Mann-Whitney test, the Spearman test, and multiple linear regression were used as statistical tests.

Results

Finally 246 patients (68% females) were included and 20 (8%) had ScH. This group, was older (median, Q1-Q3: 77,72-78; 72,68-77 years, p=0.01) and DM was less frequent than in the euthyroid group (35 vs 58%, p=0.039). Lower fasting glucose (-20%,p=0.01), GFR (-14%,p=0.01) and freeT4 (-10%,p<0.001) were found compared to euthyroid patients. A higher prevalence of Kidney failure was found in ScH (80 vs. 46%, p=0.003) vs. euthyroid individuals. Significant correlations with GFR were detected: age (r-0.482,p<0.001), TSH (r-0.172,p=0.004), IL-6 (r-0.150,p=0.047), TNF-α (r-0.274,p<0.001), uACR (r-0.170,p=0.009) and CIMT(r-0.189,p=0.004). By multiple linear regression, in a model adjusted by age, sex, BMI, uACR, S, DM, TNF-α and HBP, TSH (Bst -0.14, p=0.023, R2 = 0.25) was found an independent predictor of GFR.

Conclusion

In older adults with high CVD risk, ScH is associated with lower renal function, and this relationship is present regardless of other cardiometabolic risk factors. These results suggest that ScH could contribute to low GFR and excess CVD risk, although this hypothesis should be addressed in longitudinal studies.

24-h Urinary Calcium Excretion and Renal Outcomes in Hospitalized Patients with and without Chronic Kidney Disease

This study investigated the impact of 24-h urinary calcium excretion (UCaE) on renal function decline in hospitalized patients with and without chronic kidney disease (CKD). This study enrolled 3815 CKD patients in stages 1-4 and 1133 non-CKD patients admitted to the First Center of the Chinese PLA General Hospital between January 2014 and July 2022. The primary outcome for CKD patients was a composite of CKD progression, defined as a 40% decline in estimated glomerular filtration rate (eGFR) or end-stage kidney disease. Annual eGFR change was the secondary outcome. For non-CKD patients, the primary outcome was an eGFR decline of ≥20% or CKD incidence, while annual eGFR change was the secondary outcome. The association between UCaE and kidney function decline was assessed using Cox proportional hazards and generalized linear models. Primary outcomes were observed in 813 CKD patients and 109 non-CKD patients over a median follow-up of 3.0 and 4.1 years, respectively. For CKD patients, every 1-mmol/d increase in UCaE was associated with a 15% decreased risk of CKD progression. The hazard ratio (HR) was 0.85, with a 95% confidence interval (CI) of 0.77-0.93. For non-CKD patients, the risk of renal function decline decreased by 11%. The multivariate models indicated that there was an annual decrease in eGFR in both CKD and non-CKD patients, with a reduction of 0.122 mL/min/1.73 m²/year (p < 0.001) and 0.046 mL/min/1.73 m²/year (p = 0.004), respectively, for every 1-mmol/d increase in UCaE. CKD experiences a decrease in 24-h UCaE as early as stage 1, with a significant decline in stage 4. CKD and non-CKD patients with lower UCaE levels are at an increased risk of renal decline, regardless of other variables.

Diagnosis of Chronic Kidney Disease and Assessing Glomerular Filtration Rate

Chronic kidney disease (CKD) is a silent progressive disease. It is diagnosed by assessing filtration and markers of kidney damage such as albuminuria. The diagnosis of CKD should include not only assessing the glomerular filtration rate (GFR) and albuminuria but also the cause. The CKD care plan should include documentation of the trajectory and prognosis. The use of a combination of serum cystatin C and creatinine concentration offers a more accurate estimation of GFR. Social determinants of health are important to address as part of the diagnosis because they contribute to CKD disparities.

Non-invasive chronic kidney disease risk stratification tool derived from retina-based deep learning and clinical factors

Despite the importance of preventing chronic kidney disease (CKD), predicting high-risk patients who require active intervention is challenging, especially in people with preserved kidney function. In this study, a predictive risk score for CKD (Reti-CKD score) was derived from a deep learning algorithm using retinal photographs. The performance of the Reti-CKD score was verified using two longitudinal cohorts of the UK Biobank and Korean Diabetic Cohort. Validation was done in people with preserved kidney function, excluding individuals with eGFR <90 mL/min/1.73 m² or proteinuria at baseline. In the UK Biobank, 720/30,477 (2.4%) participants had CKD events during the 10.8-year follow-up period. In the Korean Diabetic Cohort, 206/5014 (4.1%) had CKD events during the 6.1-year follow-up period. When the validation cohorts were divided into quartiles of Reti-CKD score, the hazard ratios for CKD development were 3.68 (95% Confidence Interval [CI], 2.88-4.41) in the UK Biobank and 9.36 (5.26-16.67) in the Korean Diabetic Cohort in the highest quartile compared to the lowest. The Reti-CKD score, compared to eGFR based methods, showed a superior concordance index for predicting CKD incidence, with a delta of 0.020 (95% CI, 0.011-0.029) in the UK Biobank and 0.024 (95% CI, 0.002-0.046) in the Korean Diabetic Cohort. In people with preserved kidney function, the Reti-CKD score effectively stratifies future CKD risk with greater performance than conventional eGFR-based methods.

Machine-learning enhancement of urine dipstick tests for chronic kidney disease detection

OBJECTIVE

Screening for chronic kidney disease (CKD) requires an estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) from a blood sample and a proteinuria level from a urinalysis. We developed machine-learning models to detect CKD without blood collection, predicting an eGFR less than 60 (eGFR60 model) or 45 (eGFR45 model) using a urine dipstick test.

MATERIALS AND METHODS

The electronic health record data (n = 220 018) obtained from university hospitals were used for XGBoost-derived model construction. The model variables were age, sex, and 10 measurements from the urine dipstick test. The models were validated using health checkup center data (n = 74 380) and nationwide public data (KNHANES data, n = 62 945) for the general population in Korea.

RESULTS

The models comprised 7 features, including age, sex, and 5 urine dipstick measurements (protein, blood, glucose, pH, and specific gravity). The internal and external areas under the curve (AUCs) of the eGFR60 model were 0.90 or higher, and a higher AUC for the eGFR45 model was obtained. For the eGFR60 model on KNHANES data, the sensitivity was 0.93 or 0.80, and the specificity was 0.86 or 0.85 in ages less than 65 with proteinuria (nondiabetes or diabetes, respectively). Nonproteinuric CKD could be detected in nondiabetic patients under the age of 65 with a sensitivity of 0.88 and specificity of 0.71.

DISCUSSION AND CONCLUSIONS

The model performance differed across subgroups by age, proteinuria, and diabetes. The CKD progression risk can be assessed with the eGFR models using the levels of eGFR decrease and proteinuria. The machine-learning-enhanced urine-dipstick test can become a point-of-care test to promote public health by screening CKD and ranking its risk of progression.

Application of SERS-based nanobiosensors to metabolite biomarkers of CKD

A clinical diagnosis of chronic kidney disease (CKD) is commonly achieved by estimating the serum levels of urea and creatinine (CR). Given the limitations of the conventional diagnostic assays, it is imperative to seek alternative, economical strategies for the detection of CKD-specific biomarkers with high specificity and selectivity. In this respect, surface-enhanced Raman spectroscopy (SERS) can be regarded as an ideal choice. SERS signals can be greatly amplified by noble metal nanoparticles (e.g., gold nanoparticles (GNPs)) of numerous sizes, shapes, and configurations to help achieve ultra-sensitive single molecule-level detection at 10^-15 M (up to 10 orders of magnitude more sensitive than fluorescence-based detection). The irregular geometry of GNPs with spike-like tips, dimers, and aggregates with small nanogaps (i.e., due to plasmon coupling such as Raman hot spots) play a pivotal role in enhancing the specificity and sensitivity of SERS. This review critically outlines the performance of SERS-based biosensors in the ultrasensitive detection of CKD biomarkers in various body fluids in terms of basic quality assurance parameters (e.g., limit of detection, figure of merit, enhancement factor, and stability of the biosensor). Moreover, the challenges and perspectives are described with respect to the expansion of such sensing techniques in practical clinical settings.

Long-Term Renal Function after Catheter Ablation of Atrial Fibrillation

Background: Atrial fibrillation (AF) is associated with the development and progression of chronic kidney disease (CKD). This study evaluated the impact of long-term rhythm outcome after catheter ablation (CA) of AF on renal function. Methods and results: The study group included 169 consecutive patients (the mean age was 59.6 ± 10.1 years, 61.5% were males) who underwent their first CA of AF. Renal function was assessed by eGFR (using the CKD-EPI and MDRD formulas), and by creatinine clearance (using the Cockcroft–Gault formula) in each patient before and 5 years after index CA procedure. During the 5-year follow-up after CA, the late recurrence of atrial arrhythmia (LRAA) was documented in 62 patients (36.7%). The mean eGFR, regardless of which formula was used, significantly decreased at 5 years following CA in patients with LRAA (all p < 0.05). In the arrhythmia-free patients, the mean eGFR at 5 years post-CA remained stable (for the CKD-EPI formula: 78.7 ± 17.3 vs. 79.4 ± 17.4, p = 0.555) or even significantly improved (for the MDRD formula: 74.1 ± 17.0 vs. 77.4 ± 19.6, p = 0.029) compared with the baseline. In the multivariable analysis, the independent risk factors for rapid CKD progression (decline in eGFR > 5 mL/min/1.73 m2 per year) were the post-ablation LRAA occurrence (hazard ratio 3.36 [95% CI: 1.25–9.06], p = 0.016), female sex (3.05 [1.13–8.20], p = 0.027), vitamin K antagonists (3.32 [1.28–8.58], p = 0.013), or mineralocorticoid receptor antagonists’ use (3.28 [1.13–9.54], p = 0.029) after CA. Conclusions: LRAA after CA is associated with a significant decrease in eGFR, and it is an independent risk factor for rapid CKD progression. Conversely, eGFR in arrhythmia-free patients after CA remained stable or even improved significantly.

Non-Diabetic Kidney Disease in Type 2 Diabetes Mellitus: A Changing Spectrum with Therapeutic Ascendancy

BACKGROUND AND OBJECTIVES

Owing to changing epidemiology and therapeutic practices, a change in the spectrum of renal involvement in Type-2 diabetes mellitus (T2DM) has also been noted. The treatment of non-diabetic kidney disease (NDKD) differs from diabetic kidney disease (DKD) and the reversibility of NDKD in many cases to normal, prompts biopsy for rapid and accurate diagnosis. Data are scarce on kidney biopsy findings in T2DM.

STUDY DESIGN & SETTING

In this observational study, we prospectively collected the data of kidney biopsies of patients aged ≥ 18 years with T2DM admitted between 1 August 2005 and 31 July 2022. The clinical, demographic and histopathological data were evaluated. The spectrum of kidney involvement in the form of DKD and/or NDKD was studied. The impact of these findings with the use of drugs retarding disease progression was also analyzed.

RESULTS

A total of 5485 biopsies were performed during the study period and of these 538 patients had T2DM. The mean age of the study population was 56.9 ± 11.5 years and 81% were males. The mean duration of DM was 6.4 ± 6.1 years. Diabetic retinopathy (DR) was noted in 29.7%. The most common indication for biopsy was an acute rise in creatinine (147, 27.3%). Amongst the 538 diabetic patients who underwent biopsy, histological features only of DKD were noted in 166 patients (33%), NDKD alone in 262 (49%) and NDKD with DKD lesions in 110 (20%). On multivariate analysis, duration of DM less than 5 years, absence of CAD, absence of DR, oliguria at presentation, an acute rise in creatinine and low C3 were associated with NDKD.

CONCLUSIONS

The prevalence of NDKD among diabetics and ATIN in particular might be on an increasing trend in the current era of changing T2DM epidemiological patterns. The use of anti-pro-teinuric agents was associated with lesser degrees of histopathological chronicity in T2DM.

Management of Type 2 Diabetic Kidney Disease in 2022: A Narrative Review for Specialists and Primary Care

Purpose of review

Kidney disease is present in almost half of Canadian patients with type 2 diabetes (T2D), and it is also the most common first cardiorenal manifestation of T2D. Despite clear guidelines for testing, opportunities are being missed to identify kidney diseases, and many Canadians are therefore not receiving the best available treatments. This has become even more important given recent clinical trials demonstrating improvements in both kidney and cardiovascular (CV) endpoints with sodium-glucose cotransporter 2 (SGLT2) inhibitors and a nonsteroidal mineralocorticoid receptor antagonist, finerenone. The goal of this document is to provide a narrative review of the current evidence for the treatment of diabetic kidney disease (DKD) that supports this new standard of care and to provide practice points.

Sources of information

An expert panel of Canadian clinicians was assembled, including 9 nephrologists, an endocrinologist, and a primary care practitioner. The information the authors used for this review consisted of published clinical trials and guidelines, selected by the authors based on their assessment of their relevance to the questions being answered.

Methods

Panelists met virtually to discuss potential questions to be answered in the review and agreed on 10 key questions. Two panel members volunteered as co-leads to write the summaries and practice points for each of the identified questions. Summaries and practice points were distributed to the entire author list by email. Through 2 rounds of online voting, a second virtual meeting, and subsequent email correspondence, the authors reached consensus on the contents of the review, including all the practice points.

Key findings

It is critical that DKD be identified as early as possible in the course of the disease to optimally prevent disease progression and associated complications. Patients with diabetes should be routinely screened for DKD with assessments of both urinary albumin and kidney function. Treatment decisions should be individualized based on the risks and benefits, patients' needs and preferences, medication access and cost, and the degree of glucose lowering needed. Patients with DKD should be treated to achieve targets for A1C and blood pressure. Renin-angiotensin-aldosterone system blockade and treatment with SGLT2 inhibitors are also key components of the standard of care to reduce the risk of kidney and CV events for these patients. Finerenone should also be considered to further reduce the risk of CV events and chronic kidney disease progression. Education of patients with diabetes prescribed SGLT2 inhibitors and/or finerenone is an important component of treatment.

Limitations

No formal guideline process was used. The practice points are not graded and are not intended to be viewed as having the weight of a clinical practice guideline or formal consensus statement. However, most practice points are well aligned with current clinical practice guidelines.

The Spanish Fabry women study: a retrospective observational study describing the phenotype of females with GLA variants

BACKGROUND

Fabry disease (FD) is an X-linked condition caused by variants in the GLA gene. Since females have two X chromosomes, they were historically thought to be carriers. Although increased knowledge has shown that females often develop the disease, data from Spain and other countries reported that females were undertreated. The aim of this study was to provide a wider and more recent description of the disease characteristics and associated management of females with a GLA variant in a Spanish cohort.

RESULTS

Ninety-seven females from 12 hospitals were included in this retrospective study. Mean age was 50.1 ± 17.2 years. Median follow-up time from GLA variant identification was 36.1 months, and most (70.1%) were identified through family screening. Variants associated with classic/non-classic phenotypes were similarly distributed (40.2%/53.6%). Missense variants were the most prevalent (n = 84, 86.6%). In the overall group, 70.4% had major organ involvement (i.e., cardiac, renal, cerebrovascular, peripheral nervous system or gastrointestinal), and 47.3% also had typical Fabry signs (angiokeratoma, cornea verticillata or increased plasma lyso-Gb3). Cardiac involvement was the most prevalent (49.5%) and the main reason for treatment initiation. A total of 33 (34%) patients received disease-specific therapy, 55% of whom were diagnosed by family screening. Females carrying variants associated with a classic phenotype had higher frequencies of clinical manifestations (92.3%) and were predominant in the treated subgroup (69.7%). Despite this, there were 34 untreated females (56.7% of total untreated), with both phenotypes represented, who had major organ involvement, with 27 of cardiac, renal or cerebrovascular nature. Age or comorbidities in this subgroup were comparable to the treated subgroup (P = 0.8 and P = 0.8, respectively).

CONCLUSIONS

Efforts have been made in recent years to diagnose and treat timely Fabry females in Spain. A high percentage of females with pathogenic variants, regardless of their associated phenotype, will likely develop disease. A proportion of females with severe disease in this cohort received specific treatment. Still a significant number of females, even with same profile as the treated ones, who may be eligible for treatment according to European recommendations, remained untreated. Reasons for this merit further investigation.

Anemia is a risk factor for rapid eGFR decline in type 2 diabetes

OBJECTIVE

To investigate the association between anemia and progression of diabetic kidney disease (DKD) in type 2 diabetes.

METHODS

This was a retrospective study. A total of 2570 in-patients with type 2 diabetes hospitalized in Jinan branch of Huashan hospital from January 2013 to October 2017 were included, among whom 526 patients were hospitalized ≥ 2 times with a median follow-up period of 2.75 years. Annual rate of eGFR decline was calculated in patients with multiple admissions. A rate of eGFR decline exceeding -5 ml/min per 1.73 m² per year was defined as rapid eGFR decline. The prevalence of DKD and clinical characteristics were compared between anemia and non-anemia patients. Correlation analysis was conducted between anemia and clinical parameters. Comparison of clinical features were carried out between rapid eGFR decline and slow eGFR decline groups. The risk factors for rapid DKD progression were analyzed using logistic regression analysis.

RESULTS

The prevalence of anemia was 28.2% among the 2570 diabetic patients, while in patients with DKD, the incidence of anemia was 37.8%. Patients with anemia had greater prevalence of DKD, higher levels of urinary albumin-to-creatinine ratio (UACR), serum creatinine, BUN, urine α1-MG, urine β2-MG, urine NAG/Cr, hsCRP, Cystatin C, homocysteine and lower eGFR, as compared to the patients without anemia. Anemia was correlated with age, UACR, eGFR, urinary NAG/Cr, hsCRP and diabetic retinopathy (DR). Logistic regression analysis of 526 patients with type 2 diabetes during the follow-up period showed that anemia was an independent risk factor for rapid eGFR decline.

CONCLUSION

Anemia is associated with worse renal function and is an independent risk factor for rapid eGFR decline in type 2 diabetes.

Clinicopathological Characteristics and Risk Factors for Rapid eGFR Decline in Chinese Patients with Biopsy-Proven Obesity-Related Glomerulopathy

AIM

To investigate the clinicopathologic features and the related risk factors for rapid estimated glomerular filtration rate (eGFR) decline in Chinese obesity-related glomerulopathy (ORG) patients.

METHODS

A total of 63 ORG patients, who underwent a renal biopsy and received follow-up for at least 12 months, were recruited in our study. These patients were classified as rapid decliners and slow decliners based on the eGFR slope value (-5.0 mL/min/1.73 m²/year). Logistic regression analysis was used to determine the risk factors for rapid eGFR decline.

RESULTS

Of the 63 ORG patients, 48 (76.2%) were male, the mean age was 38.7 ± 9.0 years, the median of urinary protein excretion was 1.62 g/24 h, 27.0% of them had nephrotic-range proteinuria, while hypoalbuminemia was observed in 7.9% of them. The incidence of obvious hypertriglyceridemia, hypertension, glucose dysmetabolism and hyperuricemia were 71.4%, 60.3%, 36.5% and 27.0%, respectively. 13 (20.6%) patients became rapid decliners during the median 45 months of follow-up. Their mean BMI was 31.8 ± 3.6 kg/m², the median of baseline eGFR and urinary protein excretion were 71.8 (range of 30.5-118.2) mL/min/1.73 m²/year and 3.57 g/24 h, respectively. Multivariate logistic regression analysis showed that smoking (OR 9.205, 95% CI 1.704-49.740, P = 0.01), hyperuricemia (OR 5.541, 95% CI 1.079-28.460, P = 0.04) and nephrotic-range proteinuria (OR 6.128, 95% CI 1.311-28.637, P = 0.021) were the independent risk factors for rapid eGFR decline.

CONCLUSION

Chinese ORG patients were more likely to have clinical characteristics with hypertriglyceridemia, hypertension and hyperuricemia, and mild to severe degrees of urinary protein excretion at diagnosis, while patients with nephrotic-range proteinuria lacked hypoalbuminemia and hypercholesterolemia. Smoking, hyperuricemia and nephrotic-range proteinuria were independent risk factors for rapid eGFR decline in ORG patients.

Risk factors associated with the discordance in kidney function decline rate in identical twins

BACKGROUND

The rate of kidney function decline is different for each individual regardless of any difference in the medical histories. This study set out to identify the risk factors for high discordance in kidney function decline in an identical twin cohort.

METHODS

This study included 333 identical twins from the Korean Genome and Epidemiology Study who were categorized into two groups according to the estimated glomerular filtration rate (eGFR) decline: the slow and rapid progressor groups. The mean differences of variables were compared between the two groups. We calculated the difference in the annual eGFR change between twins and analyzed the risk factors associated with high discordance in twins who had > 5 mL/min/1.73 m2 /yr of the intra-twin difference in the annual eGFR decline. Identical twins with diabetes and baseline eGFR < 60 mL/min/1.73 m2 were excluded.

RESULTS

The high discordance twins showed significant differences in body mass index; waist-to-hip ratio; total body fat percentage; and levels of blood hemoglobin, serum fasting glucose, albumin, triglyceride, and uric acid; however, there were no differences in low discordance twins. Multivariable logistic regression showed that blood hemoglobin level is the only significant factor associated with high discordance of eGFR decline in twins.

CONCLUSIONS

Blood hemoglobin level may play a role in the individual differences in kidney function decline.

Urinary Sodium-to-Potassium Ratio and Incident Chronic Kidney Disease: Results From the Korean Genome and Epidemiology Study

OBJECTIVE

To evaluate the association of sodium-potassium intake balance on kidney function.

PATIENTS AND METHODS

Data from the Korean Genome and Epidemiology Study were used. The participants were enrolled between June 1, 2001, and January 31, 2003, and were followed-up until December 31, 2016. The 24-hour excretion levels of sodium and potassium were calculated using the Kawasaki formula with spot urinary potassium and sodium measurements. Participants were categorized into tertiles according to the estimated 24-hour urinary sodium-to-potassium (Na/K) ratio. The primary outcome was incident chronic kidney disease (CKD), defined as an estimated glomerular filtration rate of <60 mL/min per 1.73 m² in two or more consecutive measurements during the follow-up period.

RESULTS

This study included 4088 participants with normal kidney function. The mean age was 52.4±8.9 years, and 1747 (42.7%) were men. The median estimated 24-hour urinary sodium excretion level, potassium excretion level, and Na/K ratio (inter quartile range) were 4.9 (4.1-5.8) g/d, 2.1 (1.8-2.5) g/d, and 2.3 (1.9-2.7) g/d, respectively. During 37,950 person-years of follow-up (median, 11.5 years), 532 participants developed CKD, and the corresponding incidence rate was 14.0 (95% CI, 12.9-15.3) per 1000 person-years. Multivariable Cox hazard analysis revealed that the risk of incident CKD was significantly lower in the lowest tertile than in the highest tertile (HR, 0.78; 95% CI, 0.63-0.97). However, no significant association was found with incident CKD risk when urinary excretion levels of sodium or potassium were evaluated individually.

CONCLUSION

A low urinary Na/K ratio may relate with lower CKD development risk in adults with preserved kidney function.

Glycated Haemoglobin A1c Variability Score Elicits Kidney Function Decline in Chinese People Living with Type 2 Diabetes

Our aim was to investigate the association of glycated haemoglobin A1c (HbA1c) variability score (HVS) with estimated glomerular filtration rate (eGFR) slope in Chinese adults living with type 2 diabetes. This cohort study included adults with type 2 diabetes attending outpatient clinics between 2011 and 2019 from a large electronic medical record-based database of diabetes in China (WECODe). We estimated the individual-level visit-to-visit HbA1c variability using HVS, a proportion of changes in HbA1c of ≥0.5% (5.5 mmol/mol). We estimated the odds of people experiencing a rapid eGFR annual decline using a logistic regression and differences across HVS categories in the mean eGFR slope using a mixed-effect model. The analysis involved 2397 individuals and a median follow-up of 4.7 years. Compared with people with HVS ≤ 20%, those with HVS of 60% to 80% had 11% higher odds of experiencing rapid eGFR annual decline, with an extra eGFR decline of 0.93 mL/min/1.73 m2 per year on average; those with HVS > 80% showed 26% higher odds of experiencing a rapid eGFR annual decline, with an extra decline of 1.83 mL/min/1.73 m2 per year on average. Chinese adults with type 2 diabetes and HVS > 60% could experience a more rapid eGFR decline.

Prospective associations of circulating thrombospondin-2 level with heart failure hospitalization, left ventricular remodeling and diastolic function in type 2 diabetes

Background

Circulating thrombospondin-2 (TSP2) levels were associated with the development of heart failure (HF) in recent studies. However, these studies included only a minority of patients with type 2 diabetes, which is associated with an increased HF risk. As hyperglycemia induces TSP2 expression and its tissue expression increases in type 2 diabetes, we investigated the prospective association of circulating TSP2 with incident HF hospitalization (HHF), and its associations with longitudinal changes of echocardiographic parameters in type 2 diabetes.

Methods

Baseline serum TSP2 levels were measured in 4949 patients with type 2 diabetes to determine its association with incident HHF using multivariable Cox regression analysis. In the echocardiographic study, baseline serum TSP2 levels were measured in another 146 patients with type 2 diabetes but without cardiovascular diseases who underwent detailed transthoracic echocardiography at baseline and after 1 year.

Results

Over a median follow-up of 7.8 years, 330 of 4949 patients (6.7%) developed incident HHF. Baseline serum TSP2 levels were independently associated with the development of HHF (HR 1.31, 95%CI 1.06–1.62, p = 0.014) after adjustments for baseline conventional cardiovascular risk factors, atrial fibrillation, estimated glomerular filtration rate, albuminuria and high-sensitivity C-reactive protein level, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, loop-diuretics, aspirin, insulin, metformin and sodium-glucose co-transporter 2 inhibitors. Moreover, baseline serum TSP2 levels were independently associated with increase in average E/e’ and left atrial volume index (p = 0.04 and < 0.01, respectively).

Conclusion

Serum TSP2 levels were independently associated with both incident HHF and deterioration in diastolic function in type 2 diabetes.

Trial registration

Not Applicable

Supplementary information

The online version contains supplementary material available at 10.1186/s12933-022-01646-x.

Predicting Progression of Autosomal Dominant Polycystic Kidney Disease by Changes in the Telomeric Epigenome

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of chronic kidney disease with Polycystin (PKD) 1 and 2 gene mutation. However, the intra-familial variability in symptoms further suggests a non-Mendelian contribution to the disease. Our goal was to find a marker to track the epigenetic changes common to rapidly progressing forms of the disease. The risk of ADPKD increases with age, and aging shortens the telomere length (TL). Telomeres are a nucleoprotein structure composed mainly of three complexes, shelterin, CST and RNA-containing telomere repeat(TERRA), which protects the ends of chromosomes from degradation and fusion, and plays a role in maintaining cellular stability and in the repair of telomeric damage. TERRAs are transcribed from telomeric regions and a part of them is engaged in a DNA/RNA hybrid (R-loop) at each chromosome end. We tracked TL and TERRA levels in blood samples of 78 patients and 20 healthy control. Our study demonstrates that TL was shortened and TERRA expression levels in the DNA-attached fraction increased in autosomal dominant polycystic kidney patients with mutations in PKD1 and PKD2 compared to the control group. Moreover, it was observed that the expression of TERRA engaged in the R-loop was higher and the length of telomeres shorter in patients with ADPKD who showed rapid disease progression. Intrafamilial variation in TL and TERRA levels with the same mutation would indicate reliable epigenetic potential biomarkers in disease monitoring.

Psychotropic Drugs and Adverse Kidney Effects: A Systematic Review of the Past Decade of Research

BACKGROUND AND OBJECTIVE

Psychotropic drugs are a heterogenous group of treatments prescribed for many psychiatric disorders, often for long periods. Their effects on the kidney and its functioning are complex and a source of significant research and debate. This article aims to review recent evidence of the acute and chronic kidney adverse events of diverse psychotropes.

METHODS

A systematic search of randomized controlled trials and large observational studies (n ≥ 100) reporting the effects of psychotropic drugs on the kidney was conducted. The MEDLINE, PsycInfo, and EMBASE databases from 2011 to 2021, inclusive, were broadly searched with few restrictions and no prespecified outcomes. Two or more independent reviewers assessed and summarized all eligible studies, including risks of bias and levels of evidence.

RESULTS

In all, 1999 abstracts were screened for eligibility and 47 articles were included, which examined lithium (33), antiepileptics (10), antipsychotics (13), and antidepressants (9). No studies examining kidney adverse effects of other psychotropes, such as benzodiazepines, met inclusion criteria. Study populations were adult (8), geriatric (9), and mixed (30). Lithium was almost unanimously associated with (1) chronic kidney disease and (2) nephrogenic diabetes insipidus in methodologically diverse studies. The most supported risk factors for declining kidney functioning with lithium were advanced age, duration of lithium treatment, acute lithium toxicity, female sex, medications with known renal interactions, diabetes mellitus/hyperglycemia, and overall medical comorbidity. Supratherapeutic lithium concentrations are both the causes and consequences of acute kidney injury. Once significant chronic kidney disease has developed, four studies found that replacing lithium with other mood stabilizers does not slow progression, and the evolution to end-stage kidney disease is rare overall with modern practices. Compared to lithium, fewer studies examined antipsychotics and antiepileptics but found relatively less direct kidney harms. Antidepressants were not associated with acute or chronic kidney harms.

CONCLUSIONS

Despite the heterogeneity of findings, owing to varying methodologies and research challenges, recent studies strongly suggest that lithium is associated with an increased risk of chronic kidney disease and nephrogenic diabetes insipidus, especially in older adults and long-term lithium users. Clinicians should balance the harms of lithium against its established benefits, and ensure adequate monitoring and management of comorbidities in all patients. Weaker evidence suggests that antiepileptics such as valproate and antipsychotics result in comparatively less harm to the kidney than lithium, but warrant monitoring because of multiple direct and indirect mechanisms for potential kidney adverse events. Antidepressants do not have clear kidney adverse effects and appear safe (though potentially less effective) in the setting of kidney disease. Other classes of psychotropic drugs have received little research interest. Further research is warranted, particularly into specific antiepileptics and antipsychotics, and careful attention should be paid to mitigating important sources of bias such as confounding by indication.

Renoprotective effect of additional sodium-glucose cotransporter 2 inhibitor therapy in type 2 diabetes patients with rapid decline and preserved renal function

AIMS/INTRODUCTION

The slope of estimated glomerular filtration rate (eGFR) decline (eGFR slope) in early-stage type 2 diabetes patients might predict the future risk of end-stage renal disease. Type 2 diabetes patients who show rapid progressive eGFR decline are termed rapid decliners. Several studies of rapid decliners have investigated the efficacy of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in patients with advanced renal dysfunction; however, no studies, to our knowledge, have focused on patients with preserved renal function. Therefore, we investigated the efficacy of SGLT2i in rapid decliners with preserved renal function.

MATERIALS AND METHODS

This study enrolled type 2 diabetes patients with baseline eGFR ≥60 mL/min/1.73 m2 who had been treated with SGLT2i for ≥3 years. Among these individuals, we defined those with annual eGFR declines ≥5 mL/min/1.73 m2 per year before SGLT2i administration as rapid decliners. The primary end-point was the change in eGFR slope after SGLT2i administration.

RESULTS

Among 165 patients treated with SGLT2i for ≥3 years, 21 patients were rapid decliners with preserved renal function. The mean age and eGFR at SGLT2i administration were 58.6 years and 87.1 mL/min/1.73 m2 , respectively. The mean annual eGFR slope improved significantly in those administered SGLT2i compared with the control group (-1.00 and -4.36 mL/min/1.73 m2 per year, respectively; P < 0.001). Notably, the steeper the eGFR slope before starting SGLT2i administration, the larger the improvement of eGFR slope, which was independent of the reduction of albuminuria.

CONCLUSIONS

Early intervention with SGLT2i may have renoprotective effects in type 2 diabetes patients with rapid decline and preserved renal function.

Analysis of Specialty Nephrology Care Among Patients With Chronic Kidney Disease and High Risk of Disease Progression

Importance

Identification of patients with chronic kidney disease (CKD) with high risk of progression to kidney failure can help ensure they receive appropriate and effective nephrology care.

Objective

To examine whether patients with CKD at various levels of kidney failure risk receive nephrology care within 1 year of established risk.

Design, Setting, and Participants

This population-based, retrospective cohort study collected nationwide administrative health claims data from 156 733 adult patients who met the Kidney Disease: Improving Global Outcomes initiative CKD diagnostic criteria between January 1, 2012, and December 31, 2019, and had an available urine albumin to creatinine ratio within 90 days of a serum creatinine laboratory test. Patients with a history of dialysis or kidney transplant, a prior visit with a nephrologist in the past year, or palliative care billing codes or those who died or disenrolled within 1 year of the albumin to creatinine ratio measurement were excluded. Data analysis was performed from September 10, 2022, to February 14, 2022.

Exposures

Kidney failure risk computed with the 5-year Kidney Failure Risk Equation.

Main Outcomes and Measures

The main outcome was nephrology care rates across tiers of kidney failure risk, estimated as the proportion of individuals having a nephrologist visit within 1 year after index time.

Results

The study population consisted of 156 733 patients with CKD (mean [SD] age, 74.6 [8.4] years; 91 906 [58.6%] female; 86 457 [55.2%] White). A total of 106 004 patients (67.6%) had a low (≤1%) 5-year risk of kidney failure. Nephrology visit rates increased with higher kidney failure risk. Among the 137 highest-risk patients, 79 (57.7%; 95% CI, 48.4%-64.7%) had a nephrology visit. Among 7730 patients with risk above a 10% threshold, 3208 (41.5%; 95% CI, 40.3%-42.4%) had a nephrology visit.

Conclusions and Relevance

This study's findings suggest that nearly half of patients with CKD at high risk of progressing to kidney failure do not have a nephrologist visit within 1 year of established risk. These findings have implications in the design of risk-based guidelines for referral and in the practice of delivering nephrology care to patients with CKD.

Early Diagnosis of Kidney Damage Associated with Tobacco Use: Preventive Application

Although long-term smoking has been associated with chronic kidney disease, its effect on kidney function in early stages has not been clarified. Therefore, the proposed objectives were: (1) to identify subclinical kidney damage in smokers, through a panel of biomarkers; (2) to evaluate the progression of subclinical kidney damage after two years of consumption in these patients; and (3) study whether quitting smoking reduces kidney damage. A prospective study was carried out (patients recruited from a primary care centre and a clinical smoking unit). Kidney function was assessed using a panel of biomarkers and compared between smokers and non-smokers, taking into account potential risk factors for kidney damage. These results show, for the first time in the literature, the relationship between smoking and early (subclinical) kidney damage and provide a panel of biomarkers capable of detecting this condition (Neutrophil gelatinase-associated lipocalin, Kidney injury molecule-1, N-acetyl-beta-D-glucosaminidase, transferrin, and ganglioside-activating protein GM2). This study also indicates that subclinical damage is maintained when use continues, but can be reversed if patients stop smoking. The use of these biomarkers as diagnostic tools can be a preventive measure in the development of chronic kidney disease associated with smoking and in the prevention of acute events associated with potentially nephrotoxic pharmacological treatment in smokers. Trial registration number: NCT03850756.

Genetic Risk Score for Plasma Uric Acid Levels Is Associated With Early Rapid Kidney Function Decline in Type 2 Diabetes

CONTEXT

Observational studies have shown that elevated uric acid (UA) is associated with chronic kidney disease (CKD). However, whether the relationship is causal remains unclear.

OBJECTIVE

To determine the association of plasma UA and incident CKD and the causal relationship between plasma UA and rapid decline in kidney function (RDKF) in patients with type 2 diabetes (T2D).

METHODS

Multivariable Cox regression was conducted to evaluate the hazard ratio (HR) between plasma UA and incident CKD among 1300 normoalbuminuric patients in 2 T2D study cohorts (DN, n = 402; SMART2D, n = 898). A weighted genetic risk score (wGRS) was calculated based on 10 single nucleotide polymorphism (SNPs) identified in genome-wide association studies of UA in East Asians. Mendelian randomization (MR) analysis was performed among 1146 Chinese T2D patients without CKD (estimated glomerular filtration rate [eGFR] > 60 mL/min/1.73m2) at baseline (DN, 478; SMART2D, 668). The wGRS and individual SNPs were used as genetic instruments and RDKF was defined as eGFR decline of 5 mL/min/1.73m2/year or greater.

RESULTS

During mean follow-up of 5.2 and 5.4 years, 81 (9%) and 46 (11%) participants in SMART2D and DN developed CKD, respectively. A 1-SD increment in plasma UA conferred higher risk of incident CKD (DN, adjusted-HR = 1.40 [95% CI, 1.02-1.91], P = 0.036; SMART2D, adjusted-HR = 1.31 [95% CI, 1.04-1.64], P = 0.018). Higher wGRS was associated with increased odds for RDKF (meta-adjusted odds ratio = 1.12 [95% CI, 1.01-1.24], P = 0.030, Phet = 0.606).

CONCLUSION

Elevated plasma UA is an independent risk factor for incident CKD. Furthermore, plasma UA potentially has a causal role in early eGFR loss in T2D patients.

Workplace Outreach Program Improves Management of Chronic Kidney Disease

OBJECTIVE

Assess whether an employee outreach program improved management of chronic kidney disease (CKD).

METHODS

Participants with suspected CKD (eGFR <60 mL/min/1.73m 2 ) identified in employee health assessments in 2017 and 2018 were contacted by phone and offered physician consultation. Subsequent nephrologist visits at 11 months of follow up were compared between those who were (outreach group) and were not (control group) successfully contacted.

RESULTS

Most CKD risk factors at baseline were similar in outreach and control groups. At the end of the follow-up, outreach participants had more than 2-fold greater incidence of visiting a nephrologist compared with controls (HR = 2.3; 95% CI 1.2-4.2, P = 0.01), after adjusting for potential confounders. Conclusions: Employee outreach program increased utilization of nephrologist care.

Novel Markers in Diabetic Kidney Disease—Current State and Perspectives

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease. Along with the increasing prevalence of diabetes, DKD is expected to affect a higher number of patients. Despite the major progress in the therapy of DKD and diabetes mellitus (DM), the classic clinical diagnostic tools in DKD remain insufficient, delaying proper diagnosis and therapeutic interventions. We put forward a thesis that there is a need for novel markers that will be early, specific, and non-invasively obtained. The ongoing investigations uncover new molecules that may potentially become new markers of DKD—among those are: soluble α-Klotho and proteases (ADAM10, ADAM17, cathepsin, dipeptidyl peptidase 4, caspase, thrombin, and circulating microRNAs). This review summarizes the current clinical state-of-the-art in the diagnosis of DKD and a selection of potential novel markers, based on up-to-date literature.

A systematic review of the drug-drug interaction between statins and colchicine: Patient characteristics, etiologies, and clinical management strategies

Colchicine and statins are frequently co-prescribed for prevention and treatment of cardiovascular diseases, auto-inflammatory diseases, and gout. Both are substrates and inhibitors of the cytochrome P-450 (CYP) 3A4 isozyme and P-glycoprotein so that taken together, they represent a clinically significant interaction. Data suggest the interaction may be associated with potentially life-threatening myopathies and rhabdomyolysis. The purposes of this systematic review (SR) were to gather and appraise evidence surrounding the statin-colchicine drug interaction and discuss related risk-mitigation strategies. An electronic literature search was performed. Twenty-one articles met the protocol to be included in the qualitative analysis: 18 case reports/series, 2 retrospective observational cohort studies, and 1 retrospective case-control study. Thirty-eight patients developed an adverse drug event (ADE) receiving statin-colchicine combination therapy; 25 (66%) patients developed myopathy; 10 (26%) patients developed rhabdomyolysis, and three (8%) patients developed neuromyopathy. Over 70% of patients developed ADEs on simvastatin or atorvastatin, and 80% of studies reported moderate-to-high intensity statins. Colchicine dosing varied but ranged between 0.5 to 1.5 mg daily. Sixty-two percent of patients in the case reports/series had comorbid renal disease. Seven studies (33% of all included studies) reported patients taking concomitant interacting medications at the CYP3A4 and/or P-glycoprotein efflux pump. Seventeen studies (81% of all included studies) reported ADEs leading to hospitalization. A multivariate analysis from one case-control study identified risk factors prognosticating myopathy ADEs in patients taking statin-colchicine therapy: comorbid renal disease and/or cirrhosis, colchicine doses 1.2 mg daily or greater, and concomitant interacting medications. Clinicians must be cognizant that the statin-colchicine drug interaction may lead to patient harm and thus should employ risk-mitigation strategies for statin-associated muscle symptoms. Future studies are warranted to validate clinically relevant risk factors that are strongly associated with the complications owing to the statin-colchicine drug interaction.

NAG: potential cardiorenal biomarker indicates progression of chronic kidney disease in implantable cardioverter defibrillator patients, contrary to KIM-1

Aim: NAG and KIM-1 as markers of tubular damage are suggested as potential biomarkers for the cardiorenal syndrome. Aim of the study was to assess the prognostic capability of NAG and KIM-1 regarding progression of chronic kidney disease (CKD) in patients with implantable cardioverter defibrillator (ICD). Materials & methods: We included 313 patients with an ICD and collected plasma and urine samples. Follow-up was performed after 51 months (interquartile range [IQR]: 25-55). Outcome of interest was continuous CKD progression defined as persistent decline in estimated glomerular filtration rate category accompanied by a ≥25% drop of baseline estimated glomerular filtration rate. Results: Average four (IQR: 2-6) follow-up values of serum creatinine per patient were obtained. During follow-up 29 patients (9%) developed a continuous CKD progression. NAG was shown as independent predictor for continuous CKD progression (p = 0.01), opposite to KIM-1 (p = n.s.). Conclusion: NAG was shown as predictor for a progressive and real deterioration of kidney function in patients with ICD.

A read-world study on SGLT2 inhibitors and diabetic kidney disease progression

Background

Randomized controlled trials have demonstrated the benefits of sodium–glucose cotransporter 2 inhibitors (SGLT2is) in people with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). However, real-world data on CKD progression and the development of end-stage kidney disease (ESKD) remains scarce. Our aim was to study renal outcomes of people with diabetic kidney disease (DKD) using SGLT2is in a highly prevalent DKD population.

Methods

Between 2016 and 2019 we recruited T2DM patients in the renal and diabetic clinics in a regional hospital in Singapore. Patients prescribed SGLT2is were compared with those on standard anti-diabetic and renoprotective treatment. The outcome measures were CKD progression [a ≥25% decrease from baseline and worsening of estimated glomerular filtration rate (eGFR) categories according to the Kidney Disease: Improving Global Outcomes guidelines] and ESKD (eGFR <15 mL/min/1.73 m²).

Results

We analysed a total of 4446 subjects; 1598 were on SGLT2is. There was a significant reduction in CKD progression {hazard ratio [HR] 0.60 [95% confidence interval (CI) 0.49–0.74]} with SGLT2is. The HR for eGFR ≥45 mL/min/1.73 m² and 15–44 mL/min/1.73 m² was 0.60 (95% CI 0.47–0.76) and 0.43 (95% CI 0.23–0.66), respectively. There was also a reduction in risk for developing ESKD for the entire cohort [HR 0.33 (95% CI 0.17–0.65)] and eGFR 15–44 mL/min/1.73 m² [HR 0.24 (95% CI 0.09–0.66)]. Compared with canagliflozin and dapagliflozin, empagliflozin showed a sustained risk reduction of renal outcomes across CKD stages 1–4.

Conclusions

This real-world study demonstrates the benefits of SGLT2is on CKD progression and ESKD. The effect is more pronounced in moderate to advanced CKD patients.

Nonlinear causal effects of estimated glomerular filtration rate on myocardial infarction risks: Mendelian randomization study

BACKGROUND

Previous observational studies suggested that a reduction in estimated glomerular filtration rate (eGFR) or a supranormal eGFR value was associated with adverse cardiovascular risks. However, a previous Mendelian randomization (MR) study under the linearity assumption reported null causal effects from eGFR on myocardial infarction (MI) risks. Further investigation of the nonlinear causal effect of kidney function assessed by eGFR on the risk of MI by nonlinear MR analysis is warranted.

METHODS

In this MR study, genetic instruments for log-eGFR based on serum creatinine were developed from European samples included in the CKDGen genome-wide association study (GWAS) meta-analysis (N=567,460). Alternate instruments for log-eGFR based on cystatin C were developed from a GWAS of European individuals that included the CKDGen and UK Biobank data (N=460,826). Nonlinear MR analysis for the risk of MI was performed using the fractional polynomial method and the piecewise linear method on data from individuals of white British ancestry in the UK Biobank (N=321,024, with 12,205 MI cases).

RESULTS

Nonlinear MR analysis demonstrated a U-shaped (quadratic P value < 0.001) association between MI risk and genetically predicted eGFR (creatinine) values, as MI risk increased as eGFR declined in the low eGFR range and the risk increased as eGFR increased in the high eGFR range. The results were similar even after adjustment for clinical covariates, such as blood pressure, diabetes mellitus, dyslipidemia, or urine microalbumin levels, or when genetically predicted eGFR (cystatin C) was included as the exposure.

CONCLUSION

Genetically predicted eGFR is significantly associated with the risk of MI with a parabolic shape, suggesting that kidney function impairment, either by reduced or supranormal eGFR, may be causally linked to a higher MI risk.

Potential Role and Limitations of Estimated Glomerular Filtration Rate Slope Assessment in Cardiovascular Trials: A Review

Importance

Cardiovascular trials have traditionally been underpowered to assess advanced chronic kidney disease (CKD) outcomes, and when included as a secondary end point, trials have used progression of CKD as incidence of some variation of a composite of end-stage kidney disease (ESKD) outcomes. Such outcomes are infrequent or occur late in cardiovascular outcome trials, which highlights the need for alternate markers for assessing the impact of interventions on kidney function at an earlier stage of the disease and, from the prevention perspective, more relevant stage of the disease.

Observations

Estimated glomerular filtration rate (eGFR) slope has demonstrated strong association with subsequent progression to ESKD. With adequate sample size, treatment effects in the range of 0.5 to 1.00 mL/min/1.73 m2/y had 96% probability of predicting CKD progression, defined as doubling of serum creatinine, eGFR less than 15 mL/min/1.73 m2, or ESKD. eGFR slope can be used in patients with higher baseline values and may provide CKD progression insights when few hard kidney events are observed, especially in trials with limited follow-up. However, among trials that have determined eGFR slope, significant variations exist regarding inclusion of baseline values, calculation of eGFR values, and the follow-up period, which make it difficult to compare and gauge the incremental benefit of the interventions. There are multiple challenges in computing eGFR slope in cardiovascular trials, such as accounting for initial eGFR dip, nonlinearity, and heteroscedasticity.

Conclusions and Relevance

eGFR slope may serve as a valuable marker to determine progression of CKD in cardiovascular trials. Further work is required to standardize data collection, follow-up duration, time points for kidney function assessment, and analytic methods to compute eGFR slope in cardiovascular trials.

Management of hypertension and renin-angiotensin-aldosterone system blockade in adults with diabetic kidney disease: Association of British Clinical Diabetologists and the Renal Association UK guideline update 2021

People with type 1 and type 2 diabetes are at risk of developing progressive chronic kidney disease (CKD) and end-stage kidney failure. Hypertension is a major, reversible risk factor in people with diabetes for development of albuminuria, impaired kidney function, end-stage kidney disease and cardiovascular disease. Blood pressure control has been shown to be beneficial in people with diabetes in slowing progression of kidney disease and reducing cardiovascular events. However, randomised controlled trial evidence differs in type 1 and type 2 diabetes and different stages of CKD in terms of target blood pressure. Activation of the renin-angiotensin-aldosterone system (RAAS) is an important mechanism for the development and progression of CKD and cardiovascular disease. Randomised trials demonstrate that RAAS blockade is effective in preventing/ slowing progression of CKD and reducing cardiovascular events in people with type 1 and type 2 diabetes, albeit differently according to the stage of CKD. Emerging therapy with sodium glucose cotransporter-2 (SGLT-2) inhibitors, non-steroidal selective mineralocorticoid antagonists and endothelin-A receptor antagonists have been shown in randomised trials to lower blood pressure and further reduce the risk of progression of CKD and cardiovascular disease in people with type 2 diabetes. This guideline reviews the current evidence and makes recommendations about blood pressure control and the use of RAAS-blocking agents in different stages of CKD in people with both type 1 and type 2 diabetes.