Combined application of eGFR and albuminuria for the precise diagnosis of stage 2 and 3a CKD in the elderly

A systematic review of statistical methodology used to evaluate progression of chronic kidney disease using electronic healthcare records

BACKGROUND

Electronic healthcare records (EHRs) are a useful resource to study chronic kidney disease (CKD) progression prior to starting dialysis, but pose methodological challenges as kidney function tests are not done on everybody, nor are tests evenly spaced. We sought to review previous research of CKD progression using renal function tests in EHRs, investigating methodology used and investigators' recognition of data quality issues.

METHODS AND FINDINGS

We searched for studies investigating CKD progression using EHRs in 4 databases (Medline, Embase, Global Health and Web of Science) available as of August 2021. Of 80 articles eligible for review, 59 (74%) were published in the last 5.5 years, mostly using EHRs from the UK, USA and East Asian countries. 33 articles (41%) studied rates of change in eGFR, 23 (29%) studied changes in eGFR from baseline and 15 (19%) studied progression to binary eGFR thresholds. Sample completeness data was available in 44 studies (55%) with analysis populations including less than 75% of the target population in 26 studies (33%). Losses to follow-up went unreported in 62 studies (78%) and 11 studies (14%) defined their cohort based on complete data during follow up. Methods capable of handling data quality issues and other methodological challenges were used in a minority of studies.

CONCLUSIONS

Studies based on renal function tests in EHRs may have overstated reliability of findings in the presence of informative missingness. Future renal research requires more explicit statements of data completeness and consideration of i) selection bias and representativeness of sample to the intended target population, ii) ascertainment bias where follow-up depends on risk, and iii) the impact of competing mortality. We recommend that renal progression studies should use statistical methods that take into account variability in renal function, informative censoring and population heterogeneity as appropriate to the study question.

Association between lifestyle factors and decreased kidney function in older adults: a community-based cross-sectional analysis of the Taipei City elderly health examination database

BACKGROUND

Impaired kidney function is the hallmark of chronic kidney disease (CKD), and is associated with increased risk of all-cause mortality in the elderly. In the present cross-sectional population-based study, we aimed to evaluate the associations between lifestyle factors (exercise habit, alcohol consumption, smoking history, and betel nut chewing) and decreased kidney function.

METHODS

The data from the Taipei City Elderly Health Examination Database (2006 to 2012) were extracted. Associations between risk factors and reduced estimated Glomerular filtration rate (eGFR) were evaluated by regression and stratification analyses.

RESULTS

A total of 297,603 participants were included in the final analysis, and 29.7% of them had reduced eGFR. Smoking was significantly associated with an elevated risk of reduced eGFR. While, physical exercise conferred to a significantly decreased adjusted odds ratio (aOR) in reduced eGFR (regular exercise, aOR = 0.79; occasional exercise, aOR = 0.87). Furthermore, the protective effect of exercise habit against reduced eGFR was not affected by comorbid conditions, such as hypertension, diabetes, obesity, and cardiovascular disease.

CONCLUSIONS

Engaging in physical exercise was beneficially associated with reduced eGFR in older individuals. Longitudinal or prospective studies are warranted for confirmation and extrapolation of the current findings.

Circulating Fetuin-A and Risk of All-Cause Mortality in Patients With Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Background: Investigations on the association of circulating fetuin-A with all-cause mortality risk in patients with chronic kidney disease (CKD) are conflicting. This meta-analysis aimed to provide a comprehensive estimation of the relationship between fetuin-A and all-cause mortality in CKD patients.

Methods: A systematic literature search was performed in PubMed, EMBASE, and The Cochrane Library up until 12 December 2018. Hazard risk (HR) and 95% confidence interval (CI) were pooled using random-effect or fixed-effect model models.

Results: A total of 13 studies comprising 5,169 CKD patients were included in the meta-analysis. In a comparison of individuals in the bottom third vs. the top third of baseline fetuin-A levels, the pooled multivariate-adjusted HR for the risk of all-cause mortality was 1.92 (95% CI 1.31–2.80), and the significant association was observed only in dialysis patients, but not non-dialysis patients. When fetuin-A was treated as continuous variables, per 0.1 g/L increase of fetuin-A levels was associated with a 8% lower mortality risk in dialysis patients (HR 0.92, 95% CI 0.87–0.97, p = 0.001), but per 0.01 g/L was not. Sensitivity analysis indicated the association was not adjusted by diabetes and inflammation.

Conclusion: Lower fetuin-A levels are associated with an increased risk of all-cause mortality independent of diabetes and inflammation in dialysis patients, and there may be a dose-response relationship between them.

Microalbuminuria in primary hypertension: a guide to optimal patient management?

Accurate assessment of the global risk profile is considered a prerequisite for the optimal management of hypertensive patients. In particular, the evaluation of subclinical organ damage, namely left ventricular hypertrophy, peripheral atherosclerosis and renal function, plays a key role in optimizing therapeutic targets and strategy in individual patients. Urine albumin excretion is a low-cost, easy-to-use test and a powerful predictor of cardiovascular diseases. The search for albuminuria has, therefore, become routine in the evaluation of hypertensive patients. Moreover, albuminuria has been shown to be associated with early signs of extra-renal organ damage such as left ventricular hypertrophy, and carotid atherosclerosis. Under effective antihypertensive treatment, changes in subclinical organ damage over time, especially regression of left ventricular hypertrophy, are paralleled by modification of risk status and may serve as intermediate endpoints for treatment. More recently, changes in albuminuria have also been proposed to reflect changes in the risk of cardiovascular events. If this is confirmed by large well-designed studies, microalbuminuria may not simply be regarded as a risk predictor but become itself an independent target for treatment.