Determinants of decline in glomerular filtration rate in nonproteinuric subjects with or without diabetes and hypertension

The Association of Malnutrition With Chronic Kidney Disease in the Older Chinese Population With Hypertension: Evidence From the China H-type Hypertension Registry Study

OBJECTIVE

Current evidence of the dose-response association between the geriatric nutritional risk index (GNRI) and chronic kidney disease (CKD) is limited. Hence, this study aimed to determine the association between GNRI and CKD in the elderly Chinese population with hypertension.

METHODS

Data were derived from the China H-type Hypertension Registry. A total of 9,897 elderly patients with hypertension were included in the cross-sectional analysis. GNRI was calculated using the serum albumin and weight loss and the specific formula was as follows: GNRI = [1.489 × serum albumin (g/L)] + [41.7 × (actual weight/ideal weight)]. The outcome of our study was CKD, which was defined as an estimated glomerular filtration rate value of <60 mL/minute/1.73 m2. The association between the GNRI and CKD was analyzed using multivariate logistic regression.

RESULTS

The present study population was composed of 9,897 participants with an average age of 68.67 (6.10) years. In particular, it was consisted of 4,683 (47.32%) male and 5,214 (52.68%) female participants. Overall, there was a significantly negative association between GNRI and CKD prevalence (per 1 increment; adjusted odds ratio [OR], 0.96; 95% confidence interval [CI]: 0.95-0.97). In a fully adjusted model, compared with the participants in the highest group tertiles 3 (GNRI ≥112), the participants in group tertiles 1 (GNRI <106) and group tertiles 2 (GNRI ≥106 ≤ 112) increased the prevalence of CKD by 57% (OR 1.57, 95% CI: 1.28-1.93) and 5% (OR 1.05, 95% CI: 0.86-1.28), respectively. Moreover, similar results were observed when the GNRI was assessed as a categorical variable based on the clinical cutoff values.

CONCLUSION

This cross-sectional analysis found a significant negative association between GNRI and CKD among the elderly Chinese adults with hypertension.

CKD Progression Prediction in a Diverse US Population: A Machine-Learning Model

Rationale & Objective

Chronic kidney disease (CKD) is a major cause of morbidity and mortality. To date, there are no widely used machine-learning models that can predict progressive CKD across the entire disease spectrum, including the earliest stages. The objective of this study was to use readily available demographic and laboratory data from Sonic Healthcare USA laboratories to train and test the performance of machine learning-based predictive risk models for CKD progression.

Study Design

Retrospective observational study.

Setting & Participants

The study population was composed of deidentified laboratory information services data procured from a large US outpatient laboratory network. The retrospective data set included 110,264 adult patients over a 5-year period with initial estimated glomerular filtration rate (eGFR) values between 15-89 mL/min/1.73 m2.

Predictors

Patient demographic and laboratory characteristics.

Outcomes

Accelerated (ie, >30%) eGFR decline associated with CKD progression within 5 years.

Analytical Approach

Machine-learning models were developed using random forest survival methods, with laboratory-based risk factors analyzed as potential predictors of significant eGFR decline.

Results

The 7-variable risk classifier model accurately predicted an eGFR decline of >30% within 5 years and achieved an area under the curve receiver-operator characteristic of 0.85. The most important predictor of progressive decline in kidney function was the eGFR slope. Other key contributors to the model included initial eGFR, urine albumin-creatinine ratio, serum albumin (initial and slope), age, and sex.

Limitations

The cohort study did not evaluate the role of clinical variables (eg, blood pressure) on the performance of the model.

Conclusions

Our progressive CKD classifier accurately predicts significant eGFR decline in patients with early, mid, and advanced disease using readily obtainable laboratory data. Although prospective studies are warranted, our results support the clinical utility of the model to improve timely recognition and optimal management for patients at risk for CKD progression.

Plain-Language Summary

Defined by a significant decrease in estimated glomerular filtration rate (eGFR), chronic kidney disease (CKD) progression is strongly associated with kidney failure. However, to date, there are no broadly used resources that can predict this clinically significant event. Using machine-learning techniques on a diverse US population, this cohort study aimed to address this deficiency and found that a 5-year risk prediction model for CKD progression was accurate. The most important predictor of progressive decline in kidney function was the eGFR slope, followed by the urine albumin-creatinine ratio and serum albumin slope. Although further study is warranted, the results showed that a machine-learning model using readily obtainable laboratory information accurately predicts CKD progression, which may inform clinical diagnosis and management for this at-risk population.

Association of serum total bilirubin levels with progressive renal decline and end-stage kidney disease: 10-year observational cohort study in Japanese patients with diabetes

Objective

Previous reports have demonstrated the association of serum bilirubin levels with the progression of diabetic nephropathy. The objective of this study is to assess the association of basal bilirubin levels with progressive renal decline (PRD) and end-stage kidney disease (ESKD).

Methods

A total of 298 patients with diabetes who visited Kyushu University Hospital (Japan) were recruited and followed up for 10 years. PRD was defined as a negative change in estimated glomerular filtration ratio (eGFR) >3.7%/year, 2.5th percentile. Logistic regression analysis was performed to evaluate the association of total bilirubin levels with PRD and its cut-off point was determined by receiver operating characteristic (ROC) analysis. Kaplan-Meier method and Cox hazard regression analysis were used to evaluate the predictive ability of its cut-off point for ESKD.

Results

Logistic regression model showed that total bilirubin levels were significantly associated with PRD, and ROC analysis showed that its cut-off point was 0.5 mg/dL. Kaplan-Meier method showed that the percent of patients who reached two endpoints, composite endpoint (ESKD or doubling of creatinine level) or 30% eGFR decline, was significantly higher in the low bilirubin group than in the high bilirubin group (18.5% vs 11.0%, P = 0.045; 49.1% vs 42.1%, P = 0.045, respectively, log-rank test). Cox hazard regression models confirmed the independence of the predictive ability of its cut-off point.

Conclusions

Serum total bilirubin levels were negatively associated with PRD in diabetic nephropathy and its cut-off point was 0.5 mg/dL. It may be clinically useful for identifying patients at high risk of ESKD.

Relative leucocyte telomere length is associated with incident end-stage kidney disease and rapid decline of kidney function in type 2 diabetes: analysis from the Hong Kong Diabetes Register

AIMS/HYPOTHESIS

Few large-scale prospective studies have investigated associations between relative leucocyte telomere length (rLTL) and kidney dysfunction in individuals with type 2 diabetes. We examined relationships between rLTL and incident end-stage kidney disease (ESKD) and the slope of eGFR decline in Chinese individuals with type 2 diabetes.

METHODS

We studied 4085 Chinese individuals with type 2 diabetes observed between 1995 and 2007 in the Hong Kong Diabetes Register with stored baseline DNA and available follow-up data. rLTL was measured using quantitative PCR. ESKD was diagnosed based on the ICD-9 code and eGFR.

RESULTS

In this cohort (mean ± SD age 54.3 ± 12.6 years) followed up for 14.1 ± 5.3 years, 564 individuals developed incident ESKD and had shorter rLTL at baseline (4.2 ± 1.2 vs 4.7 ± 1.2, p < 0.001) than the non-progressors (n = 3521). On Cox regression analysis, each ∆∆Ct decrease in rLTL was associated with an increased risk of incident ESKD (HR 1.21 [95% CI 1.13, 1.30], p < 0.001); the association remained significant after adjusting for baseline age, sex, HbA1c, lipids, renal function and other risk factors (HR 1.11 [95% CI 1.03, 1.19], p = 0.007). Shorter rLTL at baseline was associated with rapid decline in eGFR (>4% per year) during follow-up (unadjusted OR 1.22 [95% CI 1.15, 1.30], p < 0.001; adjusted OR 1.09 [95% CI 1.01, 1.17], p = 0.024).

CONCLUSIONS/INTERPRETATION

rLTL is independently associated with incident ESKD and rapid eGFR loss in individuals with type 2 diabetes. Telomere length may be a useful biomarker for the progression of kidney function and ESKD in type 2 diabetes.

OUP accepted manuscript

Background

Methods

Results

Conclusions

Development and External Validation of a Nomogram and a Risk Table for Prediction of Type 2 Diabetic Kidney Disease Progression Based on a Retrospective Cohort Study in China

PURPOSE

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide. Risk assessment provides information about patient prognosis, contributing to the risk stratification of patients and the rational allocation of medical resources. We aimed to develop a model for individualized prediction of renal function decline in patients with type 2 DKD (T2DKD).

PATIENTS AND METHODS

In a retrospective observational study, we followed 307 T2DKD patients and evaluated the determinants of 1) risk of doubling in serum creatinine (Scr), 2) risk of eGFR<15 mL/min/1.73m² using potential risk factors at baseline. A prediction model represented by a nomogram and a risk table was developed using Cox regression and externally validated in another cohort with 206 T2DKD patients. The discrimination and calibration of the prediction model were evaluated by the concordance index (C-index) and calibration curve, respectively.

RESULTS

Four predictors were selected to establish the final model: Scr, urinary albumin/creatinine ratio, plasma albumin, and insulin treatment. The nomogram achieved satisfactory prediction performance, with a C-index of 0.791 [95% confidence interval (CI) 0.762-0.820] in the derivation cohort and 0.793 (95% CI 0.746-0.840) in the external validation cohort. Then, all predictors were scored according to their weightings. A risk table with the highest score of 11.5 was developed. The C-index of the risk table was 0.764 (95% CI: 0.731-0.797), which was similar to the external validation cohort (0.763; 95% CI: 0.714-0.812). Additionally, the patients were divided into two groups based on the risk table, and significant differences in the probability of outcome events were observed between the high-risk (score >2) and low-risk (score ≤2) groups in the derivation and external validation cohorts (P < 0.001).

CONCLUSION

The nomogram and the risk table using readily available clinical parameters could be new tools for bedside prediction of renal function decline in T2DKD patients.

A synergistic effect of variability in estimated glomerular filtration rate with chronic kidney disease on all-cause mortality prediction in patients with type 2 diabetes: a retrospective cohort study

Background

The combination of diabetes mellitus (DM) and chronic kidney disease (CKD) is associated with a high risk of mortality. Annual assessment of the estimated glomerular filtration rate (eGFR) is recommended for patients with DM. We investigated the effect of variability in annual eGFR values on all-cause mortality in patients with type 2 DM.

Methods

In this retrospective cohort study, we enrolled patients with eGFR data between 01 Aug 2017 and 31 July 2018. We defined the index eGFR as the first available eGFR value within the enrollment year and collected additional annual eGFR data from the previous three years. A total of 3592 patients with type 2 DM were enrolled, including 959 patients with CKD (index eGFR < 60 mL/min/1.73 m²) and 2633 patients without CKD. We assessed eGFR variability by using the standard deviation (SD) of the three annual eGFR and index eGFR values. We divided patients into subgroups according to the median SD of their annual eGFR (7.62 mL/min/1.73 m²). The primary endpoint was all-cause mortality after the index eGFR was assessed.

Results

During a median follow-up of 19 months (interquartile range: 18‒20 months), 127 (3.5%) deaths occurred among all 3592 enrolled patients. The highest mortality risk was observed in the high SD with CKD group, with a hazard ratio (HR) of 2.382 [95% confidence interval (CI) 1.346‒4.215] in comparison to the low SD without CKD group after adjusting for the associated factors. In patients without CKD, a high SD was an independent risk factor for mortality (HR = 2.105, 95% CI 1.256‒3.528). According to the C-index, the mortality prediction ability was better for the index eGFR + SD model than for the index eGFR alone model (0.671 vs. 0.629, P < 0.001).

Conclusion

There was a synergistic effect of eGFR variability with single-measured eGFR for the prediction of mortality in patients with type 2 DM. The SD of the annual eGFR values was also an independent predictor of mortality in patients with an eGFR > 60 mL/min/1.73 m².

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01399-z.

Different kidney function trajectory patterns before dialysis in elderly patients: clinical implications and outcomes

Background. Identifying trajectories of kidney disease progression in chronic kidney disease (CKD) patients may help to deliver better care. We aimed to identify and characterize trajectories of renal function decline in CKD patients and to investigate their association with mortality after dialysis.

Methods. This retrospective cohort study included 378 CKD patients who initiated dialysis (aged 65 years and over) between 2009 and 2016. Were considered mixed models using linear quadratic and cubic models to define the trajectories, and we used probabilistic clustering procedures. Patient characteristics and care practices at and before dialysis were examined by multivariable multinomial logistic regression. The association of these trajectories with mortality after dialysis was examined using Cox models.

Results. Four distinct groups of eGFR trajectories decline before dialysis were identified: slower decline (18.3%), gradual decline (18.3%), early rapid decline (41.2%), and rapid decline (22.2%). Patients with rapid eGFR decline were more likely to have diabetes, more cognitive impairment, to have been hospitalized before dialysis, and were less likely to have received pre-dialysis care compared to the patients with a slower decline. They had a higher risk of death within the first and fourth year after dialysis initiation, and after being more than 4 years in dialysis.

Conclusions. There are different patterns of eGFR trajectories before dialysis initiation in the elderly, that may help to identify those who are more likely to experience an accelerated decline in kidney function, with impact on pre ESKD care and in the mortality risk after dialysis.

Arteriolar hyalinosis is related to rapid GFR decline and long-standing GFR changes observed on renal biopsies in normo-microalbuminuric type 2 diabetic patients

AIMS

Whether or not renal structural changes, especially arteriolar hyalinosis, are related to the rate of renal functional decline and increase in urinary albumin excretion (UAE) at the early stage of diabetic nephropathy in patients with type 2 diabetes is still unknown. Our previous study determined that arteriolar hyalinosis is an independent risk factor for low GFR. We sought to determine whether arteriolar hyalinosis is also a risk factor for rapidly progressive decline in GFR.

METHODS

We evaluated 22 type 2 diabetic patients with normo- or microalbuminuria who took part in the previous study, to clarify which renal histological factors were associated with changes in UAE and the glomerular filtration rate (GFR) during 11.0 ± 3.0 years of follow-up. Light and electron microscopy-based morphometric analyses were performed to quantitatively evaluate the glomerular and interstitial structural changes.

RESULTS

In all 22 patients, the GFR was significantly decreased from baseline to follow-up, while the UAE did not change markedly between the 2 periods. After 11 ± 3 years of follow-up, the GFR was significantly lower in the rapid decliner group (annual rate of GFR decline ≥3.0%) than in the non-rapid decliner group (p = 0.017). The index of arteriolar hyalinosis (IAH) at baseline in the rapid decliners was significantly larger than in the non-rapid decliners (p = 0.015). The IAH showed a significant negative correlation with the GFR at follow-up (r = 0.50, p = 0.018) and the annual rate in the GFR decline (r = 0.47, p = 0.027) and significant positive correlations with UAE at follow-up (r = 0.46, p = 0.034) and the annual rate in the UAE increase (r = 0.57, p = 0.005). The GFR at follow-up in patients with IAH ≥2.0 was significantly decreased from baseline (p = 0.042) and significantly lower than that of the patients with IAH <2.0 (p = 0.026), which did not decrease significantly from baseline. The frequency of rapid decliners was larger in the IAH ≥2.0 than in the IAH <2.0 patients (p = 0.037).

CONCLUSIONS

Aggravated arteriolar hyalinosis was a risk factor for a rapid GFR decline. This finding might reflect initial changes in early diabetic nephropathy.

Effects of renal denervation on kidney function and long-term outcomes: 3-year follow-up from the Global SYMPLICITY Registry

Aims

Several studies and registries have demonstrated sustained reductions in blood pressure (BP) after renal denervation (RDN). The long-term safety and efficacy after RDN in real-world patients with uncontrolled hypertension, however, remains unknown. The objective of this study was to assess the long-term safety and efficacy of RDN, including its effects on renal function.

Methods and results

The Global SYMPLICITY Registry is a prospective, open-label registry conducted at 196 active sites worldwide in hypertensive patients receiving RDN treatment. Among 2237 patients enrolled and treated with the SYMPLICITY Flex catheter, 1742 were eligible for follow-up at 3 years. Baseline office and 24-h ambulatory systolic BP (SBP) were 166 ± 25 and 154 ± 18 mmHg, respectively. SBP reduction after RDN was sustained over 3 years, including decreases in both office (−16.5 ± 28.6 mmHg, P < 0.001) and 24-h ambulatory SBP (−8.0 ± 20.0 mmHg; P < 0.001). Twenty-one percent of patients had a baseline estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². Between baseline and 3 years, renal function declined by 7.1 mL/min/1.73 m² in patients without chronic kidney disease (CKD; eGFR ≥60 mL/min/1.73 m²; baseline eGFR 87 ± 17 mL/min/1.73 m²) and by 3.7 mL/min/1.73 m² in patients with CKD (eGFR <60 mL/min/1.73 m²; baseline eGFR 47 ± 11 mL/min/1.73 m²). No long-term safety concerns were observed following the RDN procedure.

Conclusion

Long-term data from the Global SYMPLICITY Registry representing the largest available cohort of hypertensive patients receiving RDN in a real-world clinical setting demonstrate both the safety and efficacy of the procedure with significant and sustained office and ambulatory BP reductions out to 3 years.

Renal histology in diabetic nephropathy predicts progression to end-stage kidney disease but not the rate of renal function decline

Background

While histopathologic changes correlate with functional impairment in cross-sectional studies of diabetic nephropathy (DN), whether these findings predict future rate of kidney function loss remains uncertain. We thus sought to examine the relationship between kidney histopathology, incidence of end-stage kidney disease (ESKD), and rate of estimated glomerular filtration rate (eGFR) loss in DN.

Methods

In this longitudinal cohort study, we studied 50 adults diagnosed with biopsy-proven DN. We analyzed the histopathologic parameters of each patient’s kidney biopsy, as defined by the Renal Pathology Society classification system for DN, and tracked all available eGFR measurements post-biopsy. We additionally collected baseline clinical parameters (at the time of biopsy), including eGFR, albumin-to-creatinine ratio (ACR), and hemoglobin A_1c. Multivariable linear regression was used to assess the relationship between histologic and clinical parameters at the time of the biopsy and eGFR slope. Kaplan-Meier curves and Cox regression were used to evaluate the association between histologic and clinical parameters and ESKD incidence.

Results

Progression to ESKD was associated with worsening interstitial fibrosis score (p = 0.05), lower baseline eGFR (p = 0.02), higher ACR (p = 0.001), and faster eGFR decline (p < 0.001). The rate of eGFR decline did not associate with any histologic parameter. Baseline ACR was the only studied variable correlating with eGFR slope (rho = − 0.41).

Conclusions

Renal histology predicts ultimate progression to ESKD, but not the rate of progression. Future work is required to identify novel predictors of rapid functional decline in patients with diabetic nephropathy.

Visit-to-visit blood pressure variability and risk of chronic kidney disease: A systematic review and meta-analyses

Objective

Previous studies have shown that visit-to-visit blood pressure variability (BPV) is associated with chronic kidney disease (CKD). However, the results have not been consistent among studies. This systematic review and meta-analysis was conducted to comprehensively assess the association between visit-to-visit BPV and the risk of CKD.

Methods

Medline, Embase, and the Cochrane Library were searched from the date of inception through 1 August 2019 using the terms “blood pressure variability,” “chronic kidney disease,” “nephropathy,” and other comparable terms. The primary outcome was the development of CKD. Two reviewers extracted the data independently. Meta-analysis was performed using a random effects model.

Results

Fourteen studies were included in the systematic review and meta-analysis. The risk of CKD was significantly greater in patients with high baseline systolic blood pressure variability (SBPV) than in patients with low baseline SBPV: the standard deviation (SD) showed relative risk (RR) of 1.69 and 95% CI of 1.38–2.08, the coefficient of variation (CV) showed RR of 1.23 and 95% CI of 1.12–1.36, and variance independent of mean (VIM) showed RR of 1.40 and 95% CI of 1.15–1.71. RRs for each unit increase in visit-to-visit SBPV and risk of CKD were 1.05 (95% CI: 1.03–1.07) for SD, 1.06 (95% CI: 1.03–1.09) for CV, and 1.1 (95% CI: 0.96–1.25) for VIM. Diastolic BPV was similarly predictive of CKD based on SD and CV.

Conclusions

Increased visit-to-visit BPV might be an independent risk factor for CKD. However, significant heterogeneity was present; thus, future prospective studies are needed to confirm our findings. Our results indicate that treatment of hypertension should control blood pressure levels and prevent abnormal fluctuations in blood pressure to reduce the risk of CKD.

Kidney function and nephrotoxic drug use among older home-dwelling persons with or without diabetes in Finland

Background

Due to these changes in kidney function, aging kidneys are more prone to drug-induced impairments in renal properties. Diabetes has been associated with the declined kidney function and an elevated risk of renal failure. The aim of this study is to compare kidney function and potentially nephrotoxic drug use among home-dwelling older persons with or without diabetes.

Methods

A total of 259 persons with and 259 persons without diabetes and aged ≥65 years were randomly selected to participate in a health examination with complete data gathered from 363 individuals (187 with diabetes and 176 without diabetes). The estimated glomerular filtration rate (eGFR) was calculated using CKD-EPI equation. Each participant was categorized based on the nephrotoxic profile of their medications.

Results

There were no differences in mean eGFR values (77.5 ± 18.8 vs. 80.5 ± 14.8 ml/min/1.73m², p = 0.089) or in the proportion of participants with eGFR < 60 ml/min/1.73m² among persons with diabetes (16% vs. 10%, p = 0.070), compared to persons without diabetes. Potentially nephrotoxic drug use was similar between the groups. The mean number of potentially nephrotoxic drugs was 1.06 ± 0.88 in those with and 0.97 ± 1.05 in those without diabetes (p = 0.39).

Conclusions

The kidney function of older persons with diabetes does not differ from that of older persons without diabetes and furthermore potentially nephrotoxic drug use seem to play only a minor role in the decline in kidney function among home-dwelling persons in the Inner-Savo district.

Sarcopenic obesity is associated with a faster decline in renal function in people with type 2 diabetes

AIM

To evaluate the association between sarcopenic obesity and the decline in estimated GFR in people with type 2 diabetes.

METHODS

We enrolled 745 people with type 2 diabetes (mean age 64.6 years, 53.6% men). Body composition was evaluated using dual-energy X-ray absorptiometry. Skeletal muscle index, calculated as appendicular non-fat mass (kg) divided by height squared (m² ), was used to determine sarcopenia. Sarcopenic obesity was defined as the coexistence of sarcopenia and a ratio of android to gynoid fat mass greater than the median values in each gender. The association of sarcopenic obesity both with the annual rate of decline in estimated GFR and a >30% decline in estimated GFR was evaluated using multivariate linear regression models and Cox proportional hazard models, respectively.

RESULTS

Participants with sarcopenic obesity were at an increased risk of a high annual rate of decline in estimated GFR, even after adjustment for the confounding variables (standardized β = -0.228, P <0.001). Sarcopenic obesity was also significantly associated with risk of a >30% decline in estimated GFR (hazard ratio 4.52, 95% CI 2.16-9.47; P < 0.01) in multivariate model.

CONCLUSIONS

Sarcopenic obesity evaluated by dual energy X-ray absorptiometry is associated with a faster decline in renal function in people with type 2 diabetes.

Relationship between hemoglobin A1c and serum troponin in patients with diabetes and cardiovascular events

Objectives

Diabetes mellitus is a group of metabolic disorders associated with high risk for cardiovascular disease. Although troponins are primarily clinically used for the diagnosis of acute coronary syndrome, they are also used in risk assessment in patients with acute coronary syndrome as well as in a number of other conditions. The aim of this review was to investigate the relationship between hemoglobin A1c and serum troponin in patients with diabetes and cardiovascular events.

Methods

Hemoglobin A1_c has been chosen as the best clinical indicator of glucose control and risk of micro and macrovascular complications. We investigated cardiac troponins as a group of markers of muscle injury which includes troponin T, troponin I and troponin C. Troponin T and I are specific for myocardial injury, compared to C which is specific for skeletal muscle.

Results

In this review, we showed that there was a causal relation between hemoglobin A1_c levels and serum troponin concentrations. Hemoglobin A1_c has shown to be a positive predictive factor of incidence, mortality and morbidity of conditions such as acute coronary syndrome, arrhythmias, stroke, pulmonary embolism and other conditions that causes troponin elevation by its release in circulation.

Conclusions

Chronic hyperglycemia decreases glomerular filtration and consequently decreases troponin elimination and also by affecting the heart microcirculation it leads to microvascular damage and consequently to ischemia which contribute to troponin concentration elevation. Furthermore, correlation between hemoglobin A1_c and troponin concentration manifests in their prognostic value for mortality.

Geriatric Nutritional Risk Index Is Associated with Unique Health Conditions and Clinical Outcomes in Chronic Kidney Disease Patients

Malnutrition is prevalent in patients with chronic kidney disease (CKD). However, current nutrition screening tools are not specific to the CKD population. In the present study, we aimed to investigate whether the geriatric nutritional risk index (GNRI), a simple tool designed for assessing nutrition-related risks in the elderly population, is associated with unique aspects of CKD such as fluid status, residual renal function, proteinuria, and inflammation, and whether it predicts clinical outcomes. The GNRI was calculated by incorporating serum albumin and anthropometric measurements in 326 patients with nondialysis stage 3–5 CKD who were followed up from September 2011 to March 2017 for end-stage renal disease (ESRD) and the composite outcome of all-cause death and cardiovascular events. Patients were stratified into tertiles according to baseline GNRI levels. Patients in the lowest GNRI tertile were more likely to have significantly higher levels of overhydration, proteinuria, and serum inflammatory markers and tended to have lower lean body mass and estimated glomerular filtration rate when compared with patients in the middle and upper GNRI tertiles. In multivariate linear regression analyses, the GNRI was independently associated with overhydration, proteinuria, and interleukin-6. During a median follow-up of 4.9 years, 101 patients developed ESRD; 40 deaths, and 68 cardiovascular events occurred. Patients in the lowest GNRI tertile had significantly increased risks of ESRD (hazard ratio (HR): 3.15, 95% confidence interval (CI): 1.95–5.07, p < 0.001) and the composite outcome (HR: 1.79, 95% CI: 1.10–2.92, p = 0.019) in fully adjusted models (reference: middle and upper GNRI tertiles). The GNRI takes CKD-specific health conditions into account. In addition, CKD patients with lower GNRI scores had a significantly higher risk of adverse clinical outcomes. Our findings suggest that the GNRI is an appropriate tool for nutrition screening and a prognostic predictor among patients with nondialysis stage 3–5 CKD.

Prognostic Value of the Estimated Glomerular Filtration Rate Decline in Hypertensive Patients Without Chronic Kidney Disease

BACKGROUND

Our objective of this study was to determine if rate of estimated glomerular filtration rate (eGFR) decline and its intensity was associated with cardiovascular risk and death in patients with hypertension whose baseline eGFR was higher than 60 ml/minute/1.73 m2.

METHODS

This study comprised 2,516 patients with hypertension who had had at least 2 serum creatinine measurements over a 4-year period. An eGFR reduction of ≥10% per year has been deemed as high eGFR and a reduction in eGFR of less than 10% per year as a low decline. The end points were coronary artery disease, stroke, transitory ischemic accident, peripheral arterial disease, heart failure, atrial fibrillation, and death from any cause. Cox regression analyses adjusted for potentially confounding factors were conducted.

RESULTS

A total of 2,354 patients with low rate of eGFR decline and 149 with high rate of eGFR decline were analyzed. The adjusted model shows that a -10% rate of eGFR decline per year is associated with a higher risk of the primary end point (HR 1.9; 95% CI 1.1-3.5; P = 0.02) and arteriosclerotic vascular disease (HR 2.2; 95% CI 1.2-4.2; P < 0.001) in all hypertensive groups. The variables associated to high/low rate of eGFR decline in the logistic regression model were serum creatinine (OR 3.35; P < 0.001), gender, women (OR 15.3; P < 0.001), tobacco user (OR 1.9; P < 0.002), and pulse pressure (OR 0.99; P < 0.05).

CONCLUSIONS

A rate of eGFR decline equal to or higher than -10% per year is a marker of cardiovascular risk for patients with arterial hypertension without chronic kidney disease at baseline. It may be useful to consider intensifying the global risk approach for these patients.

Relationship of chronic kidney disease of the with glycemic status, cardiovascular diseases and laboratory indicators in patients with type 2 diabetes mellitus

Aim. To study the relationship of chronic kidney disease parameters with glycemic control, subclinical and clinical signs of cardiovascular diseases and laboratory parameters.

Material and methods. The study included 528 patients with type 2 diabetes mellitus (T2DM) aged 30-69 years. All respondents answered questions from the ARIC questionnaire about T2DM and cardiovascular diseases. We determined the ankle-brachial index, sonographic left ventricular hypertrophy, intima-media thickness and defined hypertensive, diabetic angiopathy and polyneuropathy. The levels of glycemia, lipid spectrum, creatinine, uric acid, glycohemoglobin were evaluted. Glomerular filtration rate (GFR) was calculated using the Cockroft-Gault method, and microalbuminuria (MAU) was determined using Micral tests.

Results. Glycohemoglobin did not depend on MAU (p=0,564), a decrease in GFR was accompanied by an improvement in glycemic control (p=0,393). There was a direct association between MAU and the duration of diabetes (p=0,001), in patients with a longer course of the disease GFR was reduced (p=0,001). With increasing of systolic blood pressure, MAU progressed (p=0,016), while GFR decreased (p<0,01). In patients with hypertensive angiopathy, MAU of 100 mg/dl (p=0,001) and stage 2 of chronic kidney disease (p=0,048) occurred with the highest incidence (1/4) (p=0,048). According to the survey, angina was found in patients with MAU of 100 mg/dl (p=0,006). Chronic heart failure led to the progression of albuminuria (p=0,007), in patients with clinical signs of atherosclerosis of the lower extremities, the frequency of MAU was 72-87,5% (p=0,032). The highest intima-media thickness of the right carotid artery in patients with GFR 89-60 ml/min and MAU 100 mg/dL (respectively, 1,77±0,41, 1,33±0,49) were determined. Sonographic signs of left ventricular hypertrophy were observed in 84,6% of patients with an MAU of 300 mg/dL (p=0,022), as the severity of albuminuria increased, the ejection fraction of the left ventricle decreased (p=0,003). Albuminuria increased the level of myocardial remodeling (p<0,05) and this indicator showed a direct relationship with the severity of MAU. With an increase in albuminuria, the degree of triglyceridemia increased. An increase of MAU level and a decrease in GFR was accompanied by an increase in creatininemia (p<0,001). A direct relationship was found between lithemia and MAU. Conversely, a decrease in GFR contributed to the progression of MAU (p<0,001).

Conclusion. Reduction of GFR and MAU are the major risk factors for cardiovascular diseases in the Azerbaijani population with T2DM. We suppose that periodic monitoring of these parameters for primary and secondary prevention of diabetic nephropathy plays an important role.

An exploration of ontology-based EMR data abstraction for diabetic kidney disease prediction

Diabetic Kidney Disease (DKD) is a critical and morbid complication of diabetes and the leading cause of chronic kidney disease in the developed world. Electronic medical records (EMRs) hold promise for supporting clinical decision-making with its nationwide adoption as well as rich information characterizing patients' health care experience. However, few retrospective studies have fully utilized the EMR data to model DKD risk. This study examines the effectiveness of an unbiased data driven approach in identifying potential DKD patients in 6 months prior to onset by utilizing EMR on a broader spectrum. Meanwhile, we evaluate how different levels of data granularity of Medications and Diagnoses observations would affect prediction performance and knowledge discovery. The experimental results suggest that different data granularity may not necessarily influence the prediction accuracy, but it would dramatically change the internal structure of the predictive models.

Discordance in risk factors for the progression of diabetic retinopathy and diabetic nephropathy in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

We aimed to investigate whether there are differences in the risk factors or markers for the progression of diabetic retinopathy (DR) and diabetic nephropathy (DN) in type 2 diabetes mellitus.

MATERIALS AND METHODS

We carried out a 3-year retrospective cohort study of 604 patients with type 2 diabetes mellitus. The outcomes were the progression of DR (worsening of the DR stage) and DN (an estimated glomerular filtration rate decline >12%) at the 3-year follow up. The mean hemoglobin A1c (HbA1c) level and HbA1c variability (HbA1c-VAR) were calculated.

RESULTS

The mean HbA1c and HbA1c-VAR levels were higher in the DR progressors (n = 67) than in the DR non-progressors (n = 537). The mean HbA1c was a significant predictor for DR progression independent of the duration of diabetes and HbA1c-VAR levels. The urine albumin-to-creatinine ratio at baseline and HbA1c-VAR levels were higher in the DN progressors (n = 34) than in the DN non-progressors (n = 570). The triglyceride to high-density lipoprotein cholesterol ratio at baseline tended to be higher in the DN progressors than in the DN non-progressors. HbA1c-VAR levels and the triglyceride-to-high-density lipoprotein cholesterol ratio were significant predictors for DN progression independent of estimated glomerular filtration rate and the urine albumin-to-creatinine ratio.

CONCLUSIONS

Average glycemia was significantly associated with progression of DR, whereas glycemic variability and dyslipidemia were significantly associated with progression of DN in type 2 diabetes mellitus.

Robust clinical marker identification for diabetic kidney disease with ensemble feature selection

Objective

Diabetic kidney disease (DKD) is one of the most frequent complications in diabetes associated with substantial morbidity and mortality. To accelerate DKD risk factor discovery, we present an ensemble feature selection approach to identify a robust set of discriminant factors using electronic medical records (EMRs).

Material and Methods

We identified a retrospective cohort of 15 645 adult patients with type 2 diabetes, excluding those with pre-existing kidney disease, and utilized all available clinical data types in modeling. We compared 3 machine-learning-based embedded feature selection methods in conjunction with 6 feature ensemble techniques for selecting top-ranked features in terms of robustness to data perturbations and predictability for DKD onset.

Results

The gradient boosting machine (GBM) with weighted mean rank feature ensemble technique achieved the best performance with an AUC of 0.82 [95%-CI, 0.81-0.83] on internal validation and 0.71 [95%-CI, 0.68-0.73] on external temporal validation. The ensemble model identified a set of 440 features from 84 872 unique clinical features that are both predicative of DKD onset and robust against data perturbations, including 191 labs, 51 visit details (mainly vital signs), 39 medications, 34 orders, 30 diagnoses, and 95 other clinical features.

Discussion

Many of the top-ranked features have not been included in the state-of-art DKD prediction models, but their relationships with kidney function have been suggested in existing literature.

Conclusion

Our ensemble feature selection framework provides an option for identifying a robust and parsimonious feature set unbiasedly from EMR data, which effectively aids in knowledge discovery for DKD risk factors.

A study of high-, middle- and low-molecular weight adiponectin in urine as a surrogate marker for early diabetic nephropathy using ultrasensitive immune complex transfer enzyme immunoassay

Background

For the early identification of patients at risk of developing diabetic nephropathy, we have developed an ultrasensitive immune complex transfer enzyme immunoassay to measure adiponectin in urine.

Methods

We developed immune complex transfer enzyme immunoassay for adiponectin and measured urinary adiponectin from 70 healthy subjects, 35 obese non-diabetic subjects and 20 patients with diabetes.

Results

The urinary adiponectin concentrations in patients with diabetes (3.3 ± 10.7 ng/mg creatinine) were significantly higher than those in obese subjects (0.54 ± 0.44; P < 0.01) and healthy subjects (0.46 ± 0.42; P < 0.001). The gel filtration elution profile of urine from healthy subjects showed traces of four immunoreactive peaks (high-, medium-, low-molecular weight and monomer molecules), despite the majority of blood adiponectin being high-molecular weight. However, urinary adiponectin molecules were more frequent in low-molecular weight as the estimate glomerular filtration rate decreased. Furthermore, as blood glucose concentrations rose, middle-molecular weight and high-molecular weight increased in urine. Further, urinary adiponectin concentrations correlated with estimate glomerular filtration rate ( r = −0.61, P < 0.001), but not urinary albumin. In addition, our analysis showed a significantly ( P < 0.001) higher value for urinary adiponectin in the G2 stage of chronic kidney disease classification where urinary albumin is not elevated.

Conclusion

Adiponectin increases in urine as renal function decreases, and urinary adiponectin may be useful as a surrogate marker for diabetic nephropathy risk.

Glucosuria and all-cause mortality among general screening participants

BACKGROUND

Dipstick urine tests are used for general health screening in Japan, but how the test results (e.g., glucosuria) relate to mortality is unknown.

METHODS

Subjects participated in a nationwide screening in 2008 in six districts in Japan. We identified those who might have died using the national database of death certificates from 2008 to 2012 (total registered ~ 6 million) and verified candidates with the regional National Health Insurance Agency and public health nurses. Diabetes mellitus (DM) was defined as HbA1c ≥ 6.5%, fasting blood glucose ≥ 126 mg/dl, or medicated for DM. Hazard ratio (HR) and 95% confidence interval (CI) were calculated by Cox proportional hazard analysis. Glucosuria was defined as dipstick ≥ 1 +.

RESULTS

Among 209,060 subjects, we identified 2714 fatalities (median follow-up 3.57 years). Crude mortality rates were 1.2% for those without glucosuria and 3.4% for those with glucosuria. After adjusting for sex, age, body mass index, comorbidity (DM, hypertension, and dyslipidemia), history (stroke, heart disease, and kidney disease), and lifestyle (smoking, drinking, walking, and exercise), the HR (95% CI) for dipstick glucosuria was 1.475 (1.166-1.849, P < 0.001). DM subjects with glucosuria (N = 4655) had a higher HR [1.302 (1.044-1.613, P = 0.020)] than DM subjects without glucosuria (N = 20,245), and non-DM subjects with glucosuria (N = 470) had a higher HR [2.511 (1.539-3.833, P < 0.001)] than non-DM subjects without glucosuria (N = 183,690).

CONCLUSION

Dipstick glucosuria significantly affected mortality in Japanese community-based screening participants.

Tissue expression of tubular injury markers is associated with renal function decline in diabetic nephropathy

AIMS

The pathogenesis of diabetic kidney disease (DKD) is complex and multifactorial; increasing evidence suggests that tubular injury and inflammatory process are involved in disease progression. We investigated the potential association of renal expression of tubular injury markers, neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and inflammatory markers, tumor necrosis factor receptor (TNFR) 1 and 2 with renal progression in pathologically proven diabetic nephropathy (DN).

METHODS

We identified 122 patients with confirmed DN. After excluding patients with other coexisting renal disease or estimated glomerular filtration rate (eGFR) <30mL/min/1.73m², 35 patients were included. Annual decline of (GFR decline slope) was calculated using linear regression analysis. Tissue tubular and glomerular expressions of NGAL, KIM-1, TNFR1, and TNFR2 were assessed using immunohistochemistry.

RESULTS

Median baseline urinary protein to creatinine ratio (uPCR) was 6.76 (2.18-7.61) mg/mg Cr, median baseline eGFR was 50 (43-66) mL/min per 1.73m², and median GFR decline slope was 15.6 (4.4-35.1) mL/min per 1.73m² per year. Positive correlations were observed between tubular expressions of NGAL and KIM-1, and GFR decline slopes (r=0.601, p<0.001; r=0.516, p=0.001, respectively), and between tubular expressions of KIM-1 and uPCR (r=0.596, p<0.001), and between NGAL and interstitial fibrosis and tubular atrophy (IFTA) score (r=0.391, p=0.024). No correlations were found between glomerular or tubular expressions of TNFRs, and clinical parameters including GFR decline slopes. On multivariate analysis, the association between tubular expressions of KIM-1 and GFR decline slopes was dependent on uPCR. Tubular expressions of NGAL were independently associated with GFR decline slopes, with an adjusted coefficient factor of 0.290 (95% confidence interval, 0.009-0.202, p=0.038).

CONCLUSIONS

These findings suggest that tubular injury plays a key role in the pathogenesis of DKD in high-risk patients. Further studies are warranted to determine whether tubular injury could be a therapeutic target in DKD.

Predictive abilities of cardiovascular biomarkers to rapid decline of renal function in Chinese community-dwelling population: a 5-year prospective analysis

BACKGROUND

Predictive abilities of cardiovascular biomarkers to renal function decline are more significant in Chinese community-dwelling population without glomerular filtration rate (GFR) below 60 ml/min/1.73m², and long-term prospective study is an optimal choice to explore this problem. Aim of this analysis was to observe this problem during the follow-up of 5 years.

METHODS

In a large medical check-up program in Beijing, there were 948 participants with renal function evaluated at baseline and follow-up of 5 years. Physical examinations were performed by well-trained physicians. Blood samples were analyzed by qualified technicians in central laboratory.

RESULTS

Median rate of renal function decline was 1.46 (0.42-2.91) mL/min/1.73m²/year. Rapid decline of renal function had a prevalence of 23.5% (223 participants). Multivariate linear and Logistic regression analyses confirmed that age, sex, baseline GFR, homocysteine and N-terminal pro B-type natriuretic peptide (NT-proBNP) had independently predictive abilities to renal function decline rate and rapid decline of renal function (p < 0.05 for all). High-sensitivity cardiac troponin T (hs-cTnT), carotid femoral pulse wave velocity and central augmentation index had no statistically independent association with renal function decline rate and rapid decline of renal function (p > 0.05 for all).

CONCLUSIONS

Homocysteine and NT-proBNP rather than hs-cTnT had independently predictive abilities to rapid decline of renal function in Chinese community-dwelling population without GFR below 60 ml/min/1.73m². Baseline GFR was an independent factor predicting the rapid decline of renal function. Arterial stiffness and compliance had no independent effect on rapid decline of renal function. This analysis has a significant implication for public health, and changing the homocysteine and NT-proBNP levels might slow the rapid decline of renal function.

Association between dipstick hematuria and decline in estimated glomerular filtration rate among Japanese patients with type 2 diabetes: A prospective cohort study [Diabetes Distress and Care Registry at Tenri (DDCRT 14)]

AIMS

To assess the association between dipstick hematuria and estimated glomerular filtration rate (eGFR) decline in Japanese patients with type 2 diabetes.

METHODS

Longitudinal data were obtained from 3068 Japanese patients with type 2 diabetes. To assess the independent association between dipstick hematuria and eGFR decline, we used Cox proportional hazard model adjusted for potential confounders.

RESULTS

Median follow-up period was 699.7days. Mean age, body mass index (BMI), and HbA1c level were 65.7years, 24.6kg/m², and 7.5% (58.1mmol/mol), respectively. Positive dipstick hematuria was significantly associated with baseline eGFR and severity of albuminuria (p<0.001). The multivariable-adjusted hazard ratio for eGFR decline in patients with dipstick hematuria compared with those without dipstick hematuria was 2.19 [95% confidence interval (CI): 1.22-3.91]; this association remained significant even after the exclusion of patients who did not have diabetic retinopathy (hazard ratio: 2.39; 95% CI: 1.13-5.04).

CONCLUSION

Positive dipstick hematuria was associated with severity of albuminuria and renal function. A significant association was found between dipstick hematuria and increased risk of eGFR decline among patients with type 2 diabetes. Therefore, our results suggest that dipstick hematuria is perhaps indicative of more severe diabetic nephropathy.

Comparison between Atorvastatin and Rosuvastatin in Renal Function Decline among Patients with Diabetes

BACKGROUND

Although the beneficial effects of statin treatment in dyslipidemia and atherosclerosis have been well studied, there is limited information regarding the renal effects of statins in diabetic nephropathy. We aimed to investigate whether, and which, statins affected renal function in Asian patients with diabetes.

METHODS

We enrolled 484 patients with diabetes who received statin treatment for more than 12 months. We included patients treated with moderate-intensity dose statin treatment (atorvastatin 10 to 20 mg/day or rosuvastatin 5 to 10 mg/day). The primary outcome was a change in estimated glomerular filtration rate (eGFR) during the 12-month statin treatment, and rapid renal decline was defined as a >3% reduction in eGFR in a 1-year period.

RESULTS

In both statin treatment groups, patients showed improved serum lipid levels and significantly reduced eGFRs (from 80.3 to 78.8 mL/min/1.73 m² for atorvastatin [P=0.012], from 79.1 to 76.1 mL/min/1.73 m² for rosuvastatin [P=0.001]). A more rapid eGFR decline was observed in the rosuvastatin group than in the atorvastatin group (48.7% vs. 38.6%, P=0.029). Multiple logistic regression analyses demonstrated more rapid renal function loss in the rosuvastatin group than in the atorvastatin group after adjustment for other confounding factors (odds ratio, 1.60; 95% confidence interval, 1.06 to 2.42).

CONCLUSION

These results suggest that a moderate-intensity dose of atorvastatin has fewer detrimental effects on renal function than that of rosuvastatin.

Correlations of dietary energy and protein intakes with renal function impairment in chronic kidney disease patients with or without diabetes

Dietary energy and protein intake can affect progression of chronic kidney disease (CKD). CKD complicated with diabetes is often associated with a decline in renal function. We investigated the relative importance of dietary energy intake (DEI) and dietary protein intake (DPI) to renal function indicators in nondiabetic and diabetic CKD patients. A total of 539 Stage 3-5 CKD patients [estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m² using the Modification of Diet in Renal Disease equation] with or without diabetes were recruited from outpatient clinics of Nephrology and Nutrition in a medical center in Taiwan. Appropriateness of DEI and DPI was used to subcategorize CKD patients into four groups:(1) kidney diet (KD) A (KD-A), the most appropriate diet, was characterized by low DPI and adequate DEI; (2) KD-B, low DPI and inadequate DEI; (3) KD-C, excess DPI and adequate DEI; and (4) KD-D, the least appropriate diet, excess DPI and inadequate DEI. Inadequate DEI was defined as a ratio of actual intake/recommended intake less than 90% and adequate DEI as over 90%. Low DPI was defined as less than 110% of recommended intake and excessive when over 110%. Outcome measured was eGFR. In both groups of CKD patients, DEI was significantly lower (p<0.001) and DPI higher (p=0.002) than recommended levels. However, only in the nondiabetic CKD patients were KD-C and KD-D significantly correlated with reduced eGFR compared with KD-A at increments of -5.63 mL/min/1.73 m² (p = 0.029) and -7.72 mL/min/1.73 m² (p=0.015). In conclusion, inadequate energy and excessive protein intakes appear to correlate with poorer renal function in nondiabetic CKD patients. Patients with advanced CKD are in need of counseling by dietitians to improve adherence to diets.

Patients with type 2 diabetes having higher glomerular filtration rate showed rapid renal function decline followed by impaired glomerular filtration rate: Japan Diabetes Complications Study

AIMS

The Japan Diabetes Complications Study (JDCS), a nation-wide, multicenter, prospective study of patients with type 2 diabetes, reported that hemoglobin A_1c (HbA_1c), systolic blood pressure, and smoking were risk factors for the onset of macroalbuminuria. This study explored the risk factors for glomerular filtration rate (GFR) decline in the JDCS patients.

METHODS

We examined the 1407 JDCS patients (667 women, mean age 59years, 974 normoalbuminuria, 433 microalbuminuria) whose urinary albumin-to-creatinine ratio (UACR) and estimated GFR (eGFR) were determined at baseline with an 8-year follow-up. We divided all the patients into four groups according to baseline eGFR: G1 (120≤eGFR), G2 (90≤eGFR<120), G3 (60≤eGFR<90), G4 (eGFR<60).

RESULTS

The eGFRs in groups G1 and G2 decreased at follow-up compared to those at the baseline. The risk of annual eGFR decline rate≥3ml/min/1.73m² (rapid decliners) increased as the baseline eGFR increased. Advanced age, high HbA_1c, and UACR, or diabetic retinopathy at baseline were risk factors for the rapid decliners. Especially the G1 group had a significant risk for the rapid decliners. The frequency of the patients with GFR<60ml/min/1.73m² at the follow-up amounted to 31.1% in the rapid decliners, which was higher than 12% in the non-rapid decliners.

CONCLUSIONS

In normo- and microalbuminuric patients with type 2 diabetes, extra careful attention should be paid to patients with eGFR ≥120ml/min/1.73m² to detect cases with rapidly decreased GFR under the normal range.

Long-Term Visit-to-Visit Blood Pressure Variability and Renal Function Decline in Patients With Hypertension Over 15 Years

BACKGROUND

Visit-to-visit variability of systolic blood pressure (SBP) has been shown to contribute to cardiovascular events and all-cause mortality. However, little is known about its long-term effect on renal function. We aim to examine the relationship between visit-to-visit blood pressure variability (BPV) and decline in renal function in patients with hypertension and to determine the level of systolic BPV that is associated with significant renal function decline.

METHODS AND RESULTS

This is a 15-year retrospective cohort study of 825 hypertensive patients. Blood pressure readings every 3 months were retrieved from the 15 years of clinic visits. We used SD and coefficient of variation as a measure of systolic BPV. Serum creatinine was captured and estimated glomerular filtration rate was calculated at baseline, 5, 10, and 15 years. The mean SD of SBP was 14.2±3.1 mm Hg and coefficient of variation of SBP was 10.2±2%. Mean for estimated glomerular filtration rate slope was -1.0±1.5 mL/min per 1.73 m2 per year. There was a significant relationship between BPV and slope of estimated glomerular filtration rate (SD: r=-0.16, P<0.001; coefficient of variation: r=-0.14, P<0.001, Pearson's correlation). BPV of SBP for each individual was significantly associated with slope of estimated glomerular filtration rate after adjustment for mean SBP and other confounders. The cutoff values estimated by the receiver operating characteristic curve for the onset of chronic kidney disease for SD of SBP was 13.5 mm Hg and coefficient of variation of SBP was 9.74%.

CONCLUSIONS

Long-term visit-to-visit variability of SBP is an independent determinant of renal deterioration in patients with hypertension. Hence, every effort should be made to reduce BPV in order to slow down the decline of renal function.

Plasma and Urinary Type IV Collagen Levels for Early Detection of Nephropathy in Type 2 Diabetes Mellitus Patients

BACKGROUND

Diabetic nephropathy is a major complication with high morbidity and mortality, and leads to end stage renal disease (ESRD). Type IV collagen is the main component of the glomerular basement membrane (GBM) and the extracellular matrix. The thickening of the GBM is due to accumulation of type IV collagen and alterations in its structure and composition.

AIM

The aim of this study was to evaluate the association of plasma and urine type IV collagen with albuminuria status and to determine the clinical implications of type IV collagen as a marker in the early stage of diabetic nephropathy.

MATERIALS AND METHODS

A total of 150 type 2 diabetes mellitus patients with more than 5 year diabetic duration in the age group of 35 to 60 years were selected for this study and 50 age and sex matched healthy individuals were selected as control group. Type IV collagen (Plasma and urine), Insulin were analyzed by ELISA method and micro albumin was analyzed by turbilatex method. Routine investigations fasting plasma glucose, post prandial glucose, lipid profile parameters, serum urea and creatinine were analyzed by using Auto analyzer.

RESULTS

The plasma and urinary type IV collagen levels were significantly higher in the normoalbuminuric group with diabetes than in the control group, and increased with increasing severity of albuminuria among diabetics. Both plasma and urine type IV collagen levels showed positive correlation with albumin creatinine ratio (ACR) and regression analysis showed significant influence with ACR and also positive significant correlation of ACR with FPG, PPG, HbA1C, HOMA-IR, negative correlation with HDL cholesterol was observed.

CONCLUSION

Plasma and urinary type IV collagen can be helpful in the prediction of the subsequent development of albuminuria in type 2 diabetic patients.

Clinical predictive factors in diabetic kidney disease progression

Diabetic kidney disease (DKD) represents a major component of the health burden associated with type 1 and type 2 diabetes. Recent advances have produced an explosion of ‘novel’ assay‐based risk markers for DKD, though clinical use remains restricted. Although many patients with progressive DKD follow a classical albuminuria‐based pathway, non‐albuminuric DKD progression is now well recognized. In general, the following clinical and biochemical characteristics have been associated with progressive DKD in both type 1 and type 2 diabetes: increased hemoglobin A1c, systolic blood pressure, albuminuria grade, early glomerular filtration rate decline, duration of diabetes, age (including pubertal onset) and serum uric acid; the presence of concomitant microvascular complications; and positive family history. The same is true in type 2 diabetes for male sex category, in patients following an albuminuric pathway to DKD, and also true for the presence of increased pulse wave velocity. The following baseline clinical characteristics have been proposed as risk factors for DKD progression, but with further research required to assess the nature of any relationship: dyslipidemia (including low‐density lipoprotein, total and high‐density lipoprotein cholesterol); elevated body mass index; smoking status; hyperfiltration; decreases in vitamin D, hemoglobin and uric acid excretion (all known consequences of advanced DKD); and patient test result visit‐to‐visit variability (hemoglobin A1c, blood pressure and high‐density lipoprotein cholesterol). The development of multifactorial ‘renal risk equations’ for type 2 diabetes has the potential to simplify the task of DKD prognostication; however, there are currently none for type 1 diabetes‐specific populations. Significant progress has been made in the prediction of DKD progression using readily available clinical data, though further work is required to elicit the role of several variables, and to consolidate data to facilitate clinical implementation.

Comparison of the Rate of Renal Function Decline in NonProteinuric Patients With and Without Diabetes

BACKGROUND

Patients with diabetes and chronic kidney disease (CKD) without proteinuria are often believed to have a cause of CKD other than diabetes. It was hypothesized that if this is true, the rate of renal function decline should be similar among nonproteinuric patients with and without diabetes.

METHODS

Patients seen in the nephrology, endocrinology and general internal medicine clinics at the Medical University of South Carolina (MUSC) between 2008 and 2012 with hypertension and diabetes were identified by ICD9 diagnosis codes. Patients with less than 2 measures of serum creatinine, without urine studies over the study period and with proteinuria were excluded. Four hundred seventy-two patients met the inclusion and exclusion criteria and had an initial estimated glomerular filtration rate (eGFR) between 35 and 80 mL/min per 1.73 m2. The annual rate of decline in eGFR was estimated for each patient from the lowest eGFR in each year by fitting a regression model with random intercept and slope.

RESULTS

In unadjusted analyses, the rate of eGFR decline was greater in patients with diabetes than without diabetes (-0.71 versus -0.30 mL · min(-1) · yr(-1), P = 0.03). After adjusting for age, race, sex, baseline eGFR and use of renin-angiotensin-aldosterone system blockade, the rate of decline was still greater among patients with diabetes than among those without diabetes (-0.68 versus -0.36 mL · min(-1) · yr(-1), P = 0.03).

CONCLUSIONS

Patients with diabetes had more rapid decline in kidney function compared with individuals without diabetes, despite the absence of proteinuria. These results suggest that even in the absence of proteinuria, diabetes may be associated with CKD.

Glycated Hemoglobin and Outcomes in Patients with Advanced Diabetic Chronic Kidney Disease

Diabetes is the major risk factor for end-stage renal disease (ESRD) worldwide. In advanced chronic kidney disease (CKD), less is known about the predictive value of HbA1c. We enrolled 2401 diabetic patients with stage 3–4 and stage 5 CKD, who were classified into 4 groups according to their baseline HbA1c values (<6%, 6%–7%, 7%–9%, and >9%). During the median follow-up of 3 years, 895 patients developed ESRD, and 530 died. In linear regression analysis, higher HbA1c correlated with higher eGFR in patients with stage 5 CKD but not in stage 3–4 CKD. In Cox regression analysis, a trend toward worse clinical outcomes existed when the HbA1c level exceeded 6% in stage 3–4 CKD, but the significance was only observed for >9%. The hazard ratios (HRs) for ESRD, all-cause mortality and combined CV events with mortality in the group of HbA1c >9% were 1.6 (95% CI, 1.07 to 2.38), 1.52 (95% CI, 0.97 to 2.38) and 1.46 (95% CI, 1.02 to 2.09), respectively. This study demonstrates that the higher HbA1c level is associated higher risks for clinical outcomes in diabetic patients with stage 3–4 CKD but not in stage 5 CKD.

Early intensive treatment improves outcomes in patients with glomerular hyperfiltration and type 2 diabetes

BACKGROUND AND OBJECTIVE

Approximately 24-40% of patients with type 2 diabetes mellitus (T2DM) develop kidney damage. Our objective was to evaluate the long-term evolution of renal function using isotopic determination of GFR and urinary albumin excretion (UAE) in patients with T2DM undergoing intensive treatment for renal and cardiovascular risk factors.

PATIENTS AND METHODS

This was a single-center, prospective study of 201 patients with T2DM and UAE who initiated intensive treatment. They were followed for 17.2±6.5 years. Patients were divided into three groups, according to renal function: 167(85.6%) had stable renal function, 16(8.2%) had creatinine levels that doubled and 12(6.2%) began renal replacement therapy (RRT). We performed periodic isotopic determinations of GFR using (125)I-iothalamate.

RESULTS

There were significant differences between the three groups with respect to age, duration of T2DM at baseline, years of follow-up in the study and systolic blood pressure, serum creatinine, isotopic GFR, and UAE at baseline. Renal function evolution slopes were -1.55mL/min/1.73m(2)/year in patients with stable creatinine, -2.49mL/min/1.73m(2)/year in those with doubled creatinine, and -8.16mL/min/1.73m(2)/year in those requiring RRT. We also found that differences in renal events were determined by delayed initiation of intensive treatment.

CONCLUSION

Patients with glomerular hyperfiltration who were undergoing treatment with renin angiotensin aldosterone system blockers exhibited a better evolution in renal function, possibly because these patients initiated intensive treatment earlier. Although diabetic nephropathy is associated with classic risk factors, early initiation of intensive treatment should be a priority in order to prevent worsening renal function.

Genetic and clinical variables identify predictors for chronic kidney disease in type 2 diabetes

Type 2 diabetes and chronic kidney disease (CKD) may share common risk factors. Here we used a 3-stage procedure to discover novel predictors of CKD by repeatedly applying a stepwise selection based on the Akaike information criterion to subsamples of a prospective complete-case cohort of 2755 patients. This cohort encompassed 25 clinical variables and 36 genetic variants associated with type 2 diabetes, obesity, or fasting plasma glucose. We compared the performance of the clinical, genetic, and clinico-genomic models and used net reclassification improvement to evaluate the impact of top selected genetic variants to the clinico-genomic model. Associations of selected genetic variants with CKD were validated in 2 independent cohorts followed by meta-analyses. Among the top 6 single-nucleotide polymorphisms selected from clinico-genomic data, three (rs478333 of G6PC2, rs7754840 and rs7756992 of CDKAL1) contributed toward the improvement of prediction performance. The variant rs478333 was associated with rapid decline (over 4% per year) in estimated glomerular filtration rate. In a meta-analysis of 2 replication cohorts, the variants rs478333 and rs7754840 showed significant associations with CKD after adjustment for conventional risk factors. Thus, this novel 3-stage approach to a clinico-genomic data set identified 3 novel genetic predictors of CKD in type 2 diabetes. This method can be applied to similar data sets containing clinical and genetic variables to select predictors for clinical outcomes.

Association of elevated glycosylated hemoglobin A1c with hyperfiltration in a middle-aged and elderly Chinese population with prediabetes or newly diagnosed diabetes: a cross-sectional study

BACKGROUND

To examine whether elevated glycosylated hemoglobin A1c (HbA1c) is associated with hyperfiltration in a middle-aged and elderly Chinese population.

METHODS

Anthropometric and biochemical examinations were performed in 2491 individuals from the general population, aged 40-79 years, who participated in the Huaian Diabetes Prevention Program. The estimated glomerular filtration rate (eGFR) was calculated from creatinine levels using the CKD-EPI formula. Hyperfiltration was defined as eGFR >90(th) percentile.

RESULTS

After adjustment [for age, gender, waistline, body mass index, blood pressure, smoking, alcohol consumption, cholesterol, log(triglycerides), high-density lipoprotein, low-density lipoprotein, serum uric acid, sodium intake, hypertension, and use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers], HbA1c and fasting plasma glucose (FPG) were found to be independently positively associated with eGFR. Additionally, after multivariate adjustment, the odds ratios (95 % CI) for hyperfiltration calculated for a 1-unit increase in HbA1c and FPG were 1.396 (1.089-1.790) and 1.306 (1.117-1.526), respectively. Compared with participants with HbA1c levels <5.7%, the odds ratios (95 % CI) for hyperfiltration were 2.344 (1.025-5.364) in participants with HbA1c levels of 6.21-6.49%, and 2.965 (1.537-5.720) in those with HbA1c levels ≥ 6.5%.

CONCLUSION

Elevated HbA1c (≥ 6.21%) is associated with an increased odds of hyperfiltration in middle-aged and elderly Chinese. Longitudinal studies are needed to explore whether hyperfiltration increases the odds of diabetic nephropathy in individuals with prediabetes.

Clinical factors associated with the diagnosis and progression of diabetic nephropathy

As an important complication of diabetic mellitus, diabetic nephropathy (DN) has been the main cause of end-stage renal disease. It is of great importance to diagnose DN early, and to identify the risk factors of disease progression in order to carry out in-time and effective therapies. Previous literatures have reported the role of several clinical factors in the diagnosis and progression of DN, including age, longer diabetes duration, diabetic retinopathy, higher level of hypertension and HbA1c, and so on. However, the significance of these clinical factors is still controversial and limited. This review aimed to evaluate the values and limitations of these factors in diagnosing and predicting the renal outcome of DN.

Clinical and pathological predictors of estimated GFR decline in patients with type 2 diabetes and overt proteinuric diabetic nephropathy

BACKGROUND

The effect of clinical and pathological parameters on the estimated glomerular filtration rate (eGFR) decline has not been investigated in patients with type 2 diabetes and overt proteinuric biopsy-proven diabetic nephropathy.

METHODS

Among 198 patients with type 2 diabetes who underwent renal biopsy and were confirmed to have pure diabetic nephropathy according to the recent classification, 128 patients with overt proteinuria were enrolled. Receiver operating characteristic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) analyses were performed using models adjusted for various clinical and pathological covariates to determine the best predictors of rapid eGFR decline [defined as >14.9%/year (median eGFR decline)].

RESULTS

A model that incorporated proteinuria showed the largest area under the curve (AUC) among clinical models, which suggested that proteinuria was the best clinical predictor. Although a model incorporating interstitial fibrosis and tubular atrophy (IFTA) score did not display a significantly larger AUC than the model with proteinuria (0.843 vs 0.812, respectively, p = 0.47), a model with both IFTA score and proteinuria had a significantly larger AUC than the model with proteinuria alone (0.875 vs 0.812, respectively, p = 0.014). Similarly, the addition of IFTA score resulted in a significantly greater net reclassification improvement and integrated discrimination improvement than the model with proteinuria alone [NRI: 0.78 (95% CI: 0.43-1.13; p < 0.001), IDI: 0.13 (95% CI: 0.07-0.19; p < 0.001)].

CONCLUSIONS

Our results suggest that not only proteinuria but also tubulointerstitial lesions should be assessed to predict rapid eGFR decline in patients with type 2 diabetes who have overt proteinuria and biopsy-proven diabetic nephropathy.

Psychosocial stress and changes in estimated glomerular filtration rate among adults with diabetes mellitus

BACKGROUND

Psychosocial stress has been hypothesized to impact renal changes, but this hypothesis has not been adequately tested. The aim of this study was to examine the relationship between psychosocial stress and estimated glomerular filtration rate (eGFR) and to examine other predictors of eGFR changes among persons with diabetes mellitus (DM).

METHODS

Data from a survey conducted in 2005 by a major health maintenance organization located in the southeastern part of the United States, linked to patients' clinical and pharmacy records (n=575) from 2005 to 2008, was used. Study participants were working adults aged 25-59 years, diagnosed with DM but without advanced microvascular or macrovascular complications. eGFR was estimated using the Modification of Diet in Renal Disease equation. A latent psychosocial stress variable was created from five psychosocial stress subscales. Using a growth factor model in a structural equation framework, we estimated the association between psychosocial stress and eGFR while controlling for important covariates.

RESULTS

The psychosocial stress variable was not directly associated with eGFR in the final model. Factors found to be associated with changes in eGFR were age, race, insulin use, and mean arterial pressure.

CONCLUSION

Among fairly healthy DM patients, we did not find any evidence of a direct association between psychosocial stress and eGFR changes after controlling for important covariates. Predictors of eGFR change in our population included age, race, insulin use, and mean arterial pressure.

Effect of Non-Alcoholic Fatty Liver Disease on Estimated Glomerular Filtration Rate Could Be Dependent on Age

There is a gap between the association of non-alcoholic fatty liver disease (NAFLD) and renal function in an apparently healthy population. This study aims to assess whether NAFLD is associated with estimated glomerular filtration rate (eGFR) levels and to understand early changes of eGFR in NAFLD. A cross-sectional study was performed among apparently healthy persons who underwent general health screening including laboratory assessments and hepatic ultrasonography from January 2013 to December 2013 at the First Affiliated Hospital of Zhejiang University, College of Medicine, China. This study included 1,193 subjects with a mean age of 48 years. Prevalence of NAFLD was 31.3%. Mean eGFR was significantly lower in NAFLD than in controls (107 ± 19 mL/min/1.73 m(2) vs. 113 ± 23 mL/min/1.73 m(2), P<0.001). Correlation analysis between eGFR and NAFLD related risk factors revealed an inverse correlation between eGFR levels and some NAFLD risk factors (all P<0.01). All subjects were classified into five phases according to age. Average eGFR levels of NAFLD were lower than controls in three phases for subjects with ≤ 50 years of age (all P<0.05), while there were no significant differences on average eGFR levels between NAFLD and controls in two phases for subjects with >50 years of age (Both P>0.05). The eGFR level is significantly associated with NAFLD and its risk factors in an apparently healthy population. Effects of NAFLD on eGFR could be dependent on age.

Glycated Hemoglobin Level and Mortality in a Nondiabetic Population with CKD

BACKGROUND AND OBJECTIVES

Glycated hemoglobin (HbA1c) is used to diagnose diabetes mellitus (DM) and guide its management. The association between higher HbA1c and progression to ESRD and mortality has been demonstrated in populations with DM. This study examined the association between HbA1c and these end points in a population with CKD and without DM.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the hospital-based NephroTest cohort study, measured GFR (mGFR) was taken by (51)Cr-EDTA renal clearance and HbA1c in 1165 adults with nondialysis CKD stages 1-5 and without DM between January 2000 and December 2010. The median follow-up was 3.48 years (interquartile range, 1.94-5.82) for the competing events of ESRD and pre-ESRD mortality. Time-fixed and time-dependent Cox models were used to estimate hazard ratios (HRs) for ESRD and mortality according to HbA1c, treated continuously or in tertiles.

RESULTS

At inclusion, the mean mGFR was 42.2±19.9 ml/min per 1.73 m(2), and the mean HbA1c value was 5.5%±0.5%. During follow-up, 109 patients died, and 162 patients reached ESRD. Pre-ESRD mortality was significantly associated with HbA1c treated continuously: for every 1% higher HbA1c, the crude HR was 2.16 (95% confidence interval [95% CI], 1.27 to 3.68), and it was 1.85 (95% CI, 1.05 to 3.24) after adjustment for mGFR and other risk factors of death. After excluding incident diabetes over time, the updated mean of HbA1c remained significantly associated with higher mortality risk: adjusted HR for the highest (5.7%-6.4%) versus the lowest tertile (<5.3%) was 2.62 (95% CI, 1.16 to 5.91). There was no association with ESRD risk after adjustment for risk factors of CKD progression.

CONCLUSIONS

In a CKD cohort, HbA1c values in the prediabetes range are associated with mortality. Such values should be therefore included among the risk factors for negative outcomes in CKD populations.

Impact of tubulointerstitial lesions on anaemia in patients with biopsy-proven diabetic nephropathy

AIMS

To investigate the relationship between the progression of anaemia and renal pathological findings in patients with diabetic nephropathy.

METHODS

A total of 223 patients with diabetes underwent renal biopsy from 1985 to 2010 and were confirmed to have pure diabetic nephropathy according to the recent classification, of whom 113 (baseline haemoglobin ≥ 11 g/dl) were enrolled in the study. Linear regression analysis was used to estimate the changes in haemoglobin levels during the follow-up period.

RESULTS

In a multivariate model adjusted for clinical and histopathological variables, higher interstitial fibrosis and tubular atrophy scores were more strongly associated with a decrease in haemoglobin levels than were lower scores. Compared with an interstitial fibrosis and tubular atrophy score of 0, the standardized coefficients for interstitial fibrosis and tubular atrophy scores of 1, 2 and 3 were 0.20 (95% CI -0.31 to 0.93), 0.34 (95% CI -0.22 to 1.34) and 0.47 (95% CI 0.07 to 1.96), respectively, whereas a higher glomerular class, a higher vascular lesion score and the presence of exudative lesions were not strongly correlated with the decrease in haemoglobin.

CONCLUSIONS

Tubulointerstitial lesions that are more advanced are significantly associated with the progression of anaemia in patients with diabetic nephropathy after adjustment for numerous covariates. This finding suggests that tubulointerstitial lesions may be a useful prognostic indicator for anaemia in patients with diabetic nephropathy, and that decreased erythropoietin production attributable to the progression of tubulointerstitial lesions is a major cause of anaemia in these patients.

Presence of early CKD-related metabolic complications predict progression of stage 3 CKD: a case-controlled study

BACKGROUND

Only a subset of patients who enter stage 3 chronic kidney disease (CKD) progress to stage 4. Identifying which patients entering stage 3 are most likely to progress could improve outcomes, by allowing more appropriate referrals for specialist care, and spare those unlikely to progress the adverse effects and costliness of an unnecessarily aggressive approach. We hypothesized that compared to non-progressors, patients who enter stage 3 CKD and ultimately progress have experienced greater loss of renal function, manifested by impairment of metabolic function (anemia, worsening acidosis and mineral abnormalities), than is reflected in the eGFR at entry to stage 3. The purpose of this case-controlled study was to design a prediction model for CKD progression using laboratory values reflecting metabolic status.

METHODS

Using data extracted from the electronic health record (EHR), two cohorts of patients in stage 3 were identified: progressors (eGFR declined >3 ml/min/1.73 m2/year; n=117) and non-progressors (eGFR declined <1 ml/min/1.713 m2; n=364). Initial laboratory values recorded a year before to a year after the time of entry to stage 3, reflecting metabolic complications (hemoglobin, bicarbonate, calcium, phosphorous, and albumin) were obtained. Average values in progressors and non-progressors were compared. Classification algorithms (Naïve Bayes and Logistic Regression) were used to develop prediction models of progression based on the initial lab data.

RESULTS

At the entry to stage 3 CKD, hemoglobin, bicarbonate, calcium, and albumin values were significantly lower and phosphate values significantly higher in progressors compared to non-progressors even though initial eGFR values were similar. The differences were sufficiently large that a prediction model of progression could be developed based on these values. Post-test probability of progression in patients classified as progressors or non-progressors were 81% (73% - 86%) and 17% (13% - 23%), respectively.

CONCLUSIONS

Our studies demonstrate that patients who enter stage 3 and ultimately progress to stage 4 manifest a greater degree of metabolic complications than those who remain stable at the onset of stage 3 when eGFR values are equivalent. Lab values (hemoglobin, bicarbonate, phosphorous, calcium and albumin) are sufficiently different between the two cohorts that a reasonably accurate predictive model can be developed.

A clinical stratification tool for chronic kidney disease progression rate based on classification tree analysis

BACKGROUND

Registry-based studies have identified risk factors for chronic kidney disease (CKD) and for progression to end-stage renal disease. However, usually, these studies do not incorporate sequential measurements of kidney function and provide little information on the prognosis of individual patients. The aim of this study is to identify which combinations of demographic and clinical characteristics are useful to discriminate patients with a differential annual decline in glomerular filtration rate (GFR).

METHODS

This observational retrospective study includes patients enlisted in the registry of the Prevention of Progressive Renal Insufficiency Project of Emilia-Romagna region (Italy) from July 2004 to June 2010, with at least four serum creatinine measurements. Classification tree analysis (CTA) was used to identify subgroups of patients with a different annual GFR decline using demographic and laboratory data collected at study entry.

RESULTS

The CTA procedure generated seven mutually exclusive groups. Among patients with proteinuria, those with a baseline estimated GFR (eGFR) of >33 mL/min/1.73 m(2) exhibited the fastest illness progression in the study population (-3.655 mL/min/1.73 m(2)), followed by patients with a baseline eGFR of <33 mL/min/1.73 m(2) and a baseline serum phosphorus of >4.3 mg/dL (-2.833 mL/min/1.73 m(2)). Among patients without proteinuria, those aged <67 years exhibited a significantly faster progression, which was even faster for the subgroup with diabetes. Among patients aged >67 years, females had on average a stable eGFR over time, with a large variability.

CONCLUSIONS

It is possible to rely on a few variables typically accessible in routine clinical practice to stratify patients with a different CKD progression rate. Stratification can be used to guide decisions about the follow-up schedule, treatments to slow progression of kidney disease, prevent its complications and to begin planning for dialysis and transplantation.

Dynamic and dual effects of glycated hemoglobin on estimated glomerular filtration rate in type 2 diabetic outpatients

BACKGROUND

Diabetic nephropathy is the leading cause of incident end-stage renal disease in Taiwan. Previous studies on the consistent benefits of glycemic control in diabetic nephropathy focused primarily on delaying microalbuminuria. However, this effect on glomerular filtration rate (GFR) remains controversial. This study aims to establish a model that explains the controversial effects of glycated hemoglobin (HbA1C) on GFR.

METHODS

This retrospective cohort study followed subjects with type 2 diabetes mellitus, who were enrolled between June 2006 and December 2006, for 4 years. The effects of HbA1C on estimated GFR (eGFR) were examined both cross-sectionally and longitudinally. The dual effects of HbA1C on eGFR, and how renal function interferes with these effects, were investigated.

RESULTS

Of the 1,992 subjects enrolled, 1,699 completed the follow-up. HbA1C was positively correlated with eGFR in the cross-sectional study (β coefficient = 1.44, 95% CI: 0.71-2.17, p = 0.0001). In the longitudinal study, higher baseline HbA1C resulted in a greater decline in eGFR. The annual eGFR decline rates were -1.89, -1.29, and -0.68 ml/min/1.73 m(2)/year for baseline HbA1C >9, 7 to ≤9, and ≤7%, respectively. The eGFR value was simultaneously affected by concurrent (β coefficient = 0.78, 95% CI: 0.48-1.08, p < 0.0001) and preceding HbA1C (-0.52, -0.82 to -0.23, p < 0.0001). The positive effects of concurrent HbA1C on eGFR reached statistical significance at all stages of chronic kidney disease (CKD); however, the negative effects of preceding HbA1C only applied to CKD stages 3 and 4.

CONCLUSIONS

We developed a new model that demonstrates how preceding and concurrent HbA1C simultaneously affect eGFR in opposing ways. The dynamic effects varied among different CKD stages. The deterioration in eGFR at CKD stages 3 and 4 may be postponed by intensive glycemic control. Further prospective studies may be necessary to clarify the specific CKD stage(s) that will benefit from intensive glycemic control.