Cardiovascular Disease in Early Stages of Chronic Kidney Disease in a Chinese Population

Cardiac transcriptomic changes induced by early CKD in mice reveal novel pathways involved in the pathogenesis of Cardiorenal syndrome type 4

Background

Cardiorenal syndrome (CRS) type 4 is prevalent among the chronic kidney disease (CKD) population, with many patients dying from cardiovascular complications. However, limited data regarding cardiac transcriptional changes induced early by CKD is available.

Methods

We used a murine unilateral ureteral obstruction (UUO) model to evaluate renal damage, cardiac remodeling, and transcriptional regulation at 21 days post-surgery through histological analysis, RT-qPCR, RNA-seq, and bioinformatics.

Results

UUO leads to significant kidney injury, low uremia, and pathological cardiac remodeling, evidenced by increased collagen deposition and smooth muscle alpha-actin 2 expression. RNA-seq analysis identified 76 differentially expressed genes (DEGs) in UUO hearts. Upregulated DEGs were significantly enriched in cell cycle and cell division pathways, immune responses, cardiac repair, inflammation, proliferation, oxidative stress, and apoptosis. Gene Set Enrichment Analysis further revealed mitochondrial oxidative bioenergetic pathways, autophagy, and peroxisomal pathways are downregulated in UUO hearts. Vimentin was also identified as an UUO-upregulated transcript.

Conclusions

Our results emphasize the relevance of extensive transcriptional changes, mitochondrial dysfunction, homeostasis deregulation, fatty-acid metabolism alterations, and vimentin upregulation in CRS type 4 development.

Association between Decreased Estimated Glomerular Filtration Rates and Long-term Mortality in Korean Patients with Acute Myocardial Infarction

A reduced estimated glomerular filtration rate (eGFR) is a predictor for mortality in patients with acute myocardial infarction (AMI). This study aimed to compare mortality according to the GFR and eGFR calculation methods during long-term clinical follow-ups. Using the Korean Acute Myocardial Infarction Registry-National Institutes of Health Data, 13,021 patients with AMI were included in this study. Patients were divided into the surviving (n=11,503, 88.3%) and deceased (n=1,518, 11.7%) groups. Clinical characteristics, cardiovascular risk factors, and 3-year mortality-related factors were analyzed. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations. The surviving group was younger than the deceased group (62.6±12.4 vs. 73.6±10.5 years, p<0.001), whereas the deceased group had higher hypertension and diabetes prevalences than the surviving group. A high Killip class was more frequently observed in the deceased group. eGFR was significantly lower in the deceased group (82.2±24.1 vs. 55.2±28.6 ml/min/1.73 m², p<0.001). Multivariate analysis revealed that low eGFR was an independent risk factor for mortality during the 3-year follow-up. The CKD-EPI equation was more useful for predicting mortality than the MDRD equation (0.766; 95% confidence interval [CI], 0.753-0.779 vs. 0.738; 95% CI, 0.724-0.753; p=0.001). Decreased renal function was a significant predictor of mortality after 3 years in patients with AMI. The CKD-EPI equation was more useful for predicting mortality than the MDRD equation.

Association between basal septal hypertrophy and left ventricular geometry in a community population

BACKGROUND

Left ventricular (LV) geometry is closely associated with cardiovascular disease; however, few studies have evaluated the relationship between basal septal hypertrophy (BSH) and LV geometry. In this study, we examined the relationship between BSH and LV geometry in a Beijing community population.

METHODS

The clinical and echocardiographic data of 1032 participants from a community in Beijing were analyzed. BSH was defined as a basal interventricular septal thickness ≥ 14 mm and a basal septal thickness/mid-septal thickness ≥ 1.3. On the basis of their echocardiographic characteristics, patients were described as having a normal geometry, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy. Multivariable logistic regression was used to analyze the relationship between BSH, LV mass index (LVMI), and relative wall thickness (RWT).

RESULTS

The prevalence of BSH was 7.4% (95% confidence interval [CI] 5.8-9.0%). Basal and middle interventricular septal thickness, LV posterior wall thickness, and RWT were greater, while LVMI and LV end-diastolic dimension were lower in the BSH group than in the non-BSH group (p < 0.05). The BSH group accounted for the highest proportion of patients with concentric remodeling. A multivariable regression analysis showed that BSH increased by 3.99-times (odds ratio [OR] 3.99, 95% CI 2.05-7.78, p < 0.01) when RWT was > 0.42, but not when LVMI increased (OR 0.16, 95% CI 0.02-1.19, p = 0.07). There were no interactions between BSH and age, body mass index, sex, diabetes mellitus, coronary heart disease, stroke, and smoking in relation to an RWT > 0.42.

CONCLUSION

BSH was independently associated with an RWT > 0.42.

Nontraditional risk factors in chronic kidney disease: correlation between creatinine clearance, Framingham risk score, endothelial dysfunction, and inflammation

Background

Chronic kidney disease became a public health problem increasing healthcare burden. Our aim was to detect the relationship between cardiovascular risk, endothelial dysfunction, inflammation, and kidney function in chronic kidney disease patients and to detect the nontraditional factors affecting the decline in kidney functions.

Methods

A cross-sectional study including 30 male and female patients with chronic kidney disease stages 3–5. Creatinine clearance and Framingham risk score points were calculated. Carotid intimal medial thickness was measured as well as absolute flow mediated dilatation in brachial artery. Highly sensitive C-reactive protein, parathyroid hormone, kidney function tests, and lipid profile were measured.

Results

Framingham risk score points and carotid intimal medial thickness increased significantly with decreasing creatinine clearance (p 0.0025, 0.0285) respectively. A significant correlation was found between highly sensitive C-reactive protein and Framingham risk score points but not with carotid intimal medial thickness (p 0.0043, 0.2229) respectively. An inverse correlation was found between creatinine clearance and highly sensitive C-reactive protein (p 0.0174). Absolute flow mediated dilatation in brachial artery decreases with increasing Framingham risk score points and decreasing creatinine clearance (p 0.0044, 0.0269) respectively.

Conclusion

There is correlation between chronic kidney disease and impaired vascular function, subclinical atherosclerosis, and heightened inflammatory response. Chronic kidney disease patients are at increased risk of cardiovascular events with higher [10-]year cardiovascular risk.

The Risk for Incident Ischemic Heart Disease According to Estimated Glomerular Filtration Rate in A Korean Population

AIM

Chronic kidney disease, evaluated by the estimated glomerular filtration rate (eGFR), is an established risk factor for cardiovascular disease. However, the association between renal function stratified by the eGFR and the risk of incident ischemic heart disease (IHD) in a community-based Asian population is still inconclusive.

STUDY DESIGN

Retrospective longitudinal observational study.

METHOD

In data from 206,919 Korean patients registered in the National Health Insurance Corporation (NHIC), we analyzed the risk of incident IHD according to the quartiles (Q) of eGFR (ml/min/1.73 m2) (Q1 ＜71.07, Q2: 71.07-83.16, Q3: 83.17-95.49, Q4 ＞95.50). The identification of IHD was based on the International Classification of Diseases (ICD) for IHD (ICD code: I20-I25) registered in the NHIC. The Cox proportional hazards model was used to calculate the adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for IHD according to quartile groups of eGFR levels.

RESULTS

Q1 had the more unfavorable baseline metabolic conditions than the other quartile groups. Considering Q4 as the reference, the unadjusted HRs (95% CIs) for IHD increased significantly in the order of Q3 (1.42 [1.29-1.56]), Q2 (1.51 [1.38-1.67]), and Q1 (2.11 [1.93-2.30]), and fully adjusted HRs (95% CIs) increased significantly from Q2 (1.15 [1.04-1.27]) to Q1 (1.31 [1.18-1.44]).

CONCLUSION

The risk of IHD increased significantly from individuals with an eGFR ≤ 83.16. Mildly decreased renal function is a potential risk factor for IHD.

Non-Invasive Imaging for Evaluating Cardiovascular Involvement in Patients with Primary and Lupus Nephritis

Background:

Evidence suggests that proteinuric diseases, such as primary or secondary glomerulonephritis, increase cardiovascular risk, but few studies confirmed this association.

Methods:

This is a cross-sectional, observational study on 32 patients, 17 with Primary Glomerulonephritis (PG) and 15 with Lupus Glomerulonephritis (LG). The control group consisted of 32 healthy individuals. Intima-media thickness (IMT) of the left common carotid artery, carotid bifurcation and internal carotid artery was measured by ultrasound. Left ventricular myocardial deformation was assessed by the use of the Global Circumferential Strain (GCS) and the Global Longitudinal Strain (GLS) following 2-Dimensional (2D) echocardiography in all participants.

Results:

Patients with glomerulonephritis in both groups showed significantly lower GLS compared with controls (p=0.0005). There was also a significant difference in common carotid IMT values between the LG and GP group (0.45±0.09 vs. 0.58±0.17 mm, respectively; p=0.01), but there was no difference with the control group. In patient group (n=32), a significantly positive correlation was observed between C-reactive protein and proteinuria (r=0.98; p<0.0001), whereas negative correlations were found between common carotid IMT and creatinine clearance (r=-0.97; p<0.0001) and between carotid bifurcation IMT and phosphate levels (r=-0.97; p<0.0001)

Conclusion:

Subclinical systolic myocardial dysfunction is present early in the course of glomerular disease. The use of 2D GLS revealed that LG and PG patients with no cardiovascular symptoms or history and a preserved left ventricle ejection fraction on conventional echocardiography had subclinical reduction in LV global longitudinal systolic function compared with controls.

Change of Kidney Function Is Associated With All-Cause Mortality and Cardiovascular Diseases: Results From the Kailuan Study

Background

Current evaluation about the relationship of sequential change in estimated glomerular filtration rate (eGFR) and clinical outcomes are still inconsistent. We aimed to investigate the association between the change in kidney function over time and the risk of all‐cause mortality and cardiovascular disease.

Methods and Results

This prospective cohort including 37 691 participants aged ≥45 years used data from the Kailuan Health Registry. The relationship of the annual percentage and absolute change in eGFR and outcomes were analyzed with Cox proportional regression. The participants were stratified according to the quintiles distribution of the percentage annual change in eGFR (Q1–Q5). After adjusting for baseline covariates including initial eGFR, participants with annual eGFR decline were at significantly greater risk for all‐cause mortality (Q1: hazard ratio, 1.22 [95% confidence interval, 1.04–1.43]; Q2: 1.19 [1.01–1.40]) than noted for patients in Q3. Cardiovascular disease risk was also significantly higher in participants with annual eGFR decline (Q1 and Q2). No significantly increased risk of adverse outcomes was noted for patients with annual eGFR increased groups (Q4 and Q5). When considering the absolute eGFR annual change rate (no/mild/rapid decline), we obtained similar results in chronic kidney disease participants, whereas non–chronic kidney disease participants had less pronounced association of eGFR decline with cardiovascular disease, though not with mortality.

Conclusions

A decline in eGFR over time is associated with higher risk for all‐cause mortality and cardiovascular disease independent of initial eGFR and other known risk factors at baseline. Our data support the serial evaluation of change in kidney function as a better prognostic indicator than single eGFR assessments.

Assessment of subclinical atherosclerosis and endothelial dysfunction in chronic kidney disease by measurement of carotid intima media thickness and flow-mediated vasodilatation in North Indian population

Background:

Chronic kidney disease (CKD) predisposes to accelerated atherosclerosis that is measured by carotid artery intima media thickness (CIMT) and brachial artery flow-mediated dilation (FMD). The aim of this study was to assess the noninvasive risk markers of subclinical atherosclerosis and endothelial dysfunction and their correlation with disease severity.

Methods and Results:

This was a cross-sectional study conducted in 62 patients with CKD: 38 predialysis and 24 on hemodialysis and 50 age- and gender-matched controls. In both the patients and controls, high-sensitivity C-reactive protein (CRP) levels, %FMD, and CIMT were measured. Patients with CKD had increased CRP levels {[5.8 (1.0–6.0)] mg/L vs [1.0 (0.5–2.20)] mg/L; P < 0.001}; %FMD was significantly lower in patients on hemodialysis (5.51%) compared with stage IV (7.62%) and stage III (15.02%) and 17.95% in control subjects (P < 0.001); and CIMT values in hemodialysis patients (0.88 ± 0.06 mm) were significantly higher compared with stage IV (0.67 ± 0.10) and stage III (0.61 ± 0.12) (P < 0.001). Increased CIMT values were seen in patients with CKD (0.82 ± 0.21 mm) than in the healthy controls (0.55 ± 0.16 mm). In patients with CKD, a significant negative correlation was found between CRP levels and FMD responses (r = −0.315; P < 0.001), while a significant positive correlation was found between CRP and CIMT values (r = 0.327; P < 0.001). Compared with predialysis, hemodialysis subjects had significantly lower FMD and higher CRP and IMT values.

Conclusion:

CKD confers a higher inflammatory status when compared with apparently healthy general population. Abnormal FMD responses and CIMT values are more commonly found in dialysis patients. Our findings suggest that CIMT and FMD can be used as noninvasive markers for early risk assessment and stratification in various stages of CKD.

Changes in Blood Pressure During Young Adulthood and Subsequent Kidney Function Decline: Findings From the Coronary Artery Risk Development in Young Adulthood (CARDIA) Study

BACKGROUND

Many studies have focused on the association between a single blood pressure (BP) measurement and risk for adverse outcomes. However, the association of BP trajectories during young adulthood with subsequent decline in kidney function has not been well defined.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

3,429 participants in the Coronary Artery Risk Development in Young Adulthood (CARDIA) Study enrolled between the ages of 18 and 30 years.

PREDICTORS

BP slope during the first 10 years of participation in CARDIA, derived from linear mixed models incorporating all repeated BP measures.

OUTCOME

Decline in estimated glomerular filtration rate (eGFR) during the interval between years 10 and 20 of CARDIA participation using cystatin C measured at years 10, 15, and 20.

RESULTS

Mean age of CARDIA participants at year 0 was 25.1 years, 56% were women, and 53% were white. Every 10-mmHg higher level of systolic (SBP) and diastolic BP (DBP) in year 10 was associated with change in eGFR of -0.09 (95% CI, -0.13 to -0.06) and -0.07 (95% CI, -0.12 to -0.03) mL/min/1.73m2 per year, respectively. Every 10-mmHg increase in SBP slope between years 0 and 10 was associated with a subsequent -0.52 (95% CI, -1.02 to -0.03) mL/min/1.73m2 per year change in kidney function after adjustment for comorbid conditions and SBP at year 10. Similarly, every 10-mmHg increase in DBP slope between years 0 and 10 was associated with a subsequent change in kidney function of -0.65 (95% CI, -1.23 to -0.07) mL/min/1.73m2 per year, after adjustment for comorbid conditions and DBP in year 10.

LIMITATIONS

Observational design.

CONCLUSIONS

During young adulthood, increasing SBP and DBP are associated with a higher rate of subsequent kidney function decline, independent of BP measured at the beginning of eGFR assessment.

FGF23 Level and Intima-Media Thickness Are Elevated From Early Stages of Chronic Kidney Disease

Considering high cardiovascular (CV) risk in chronic kidney disease (CKD), the aim of this cross-sectional study was to assess the association between carotid intima-media thickness (IMT) and fibroblast growth factor (FGF) 23 as important players in CV pathophysiology. Eighty-seven patients with mean estimated glomerular filtration rate 40.1 mL/min per 1.73 m² were involved. FGF23 and IMT were elevated from early stages of CKD. Mean IMT value was 1.10 ± 0.20 mm, being significantly elevated starting from early CKD, showing no correlation with FGF23 (r = -0.01, P = -0.91). Unlike the FGF23 level that followed worsening of kidney function, IMT was increasing only in the initial CKD stages, with no further increase from CKD stage 3 on. Although we found no direct association between current use of vitamin D and statin therapy, this may be associated with the sustained reference values of lipid and vitamin D status under treatment that further preclude worsening of IMT in patients with advanced CKD.

Use of Chronic Kidney Disease to Enhance Prediction of Cardiovascular Risk in Those at Medium Risk

Based on global cardiovascular (CV) risk assessment for example using the Framingham risk score, it is recommended that those with high risk should be treated and those with low risk should not be treated. The recommendation for those of medium risk is less clear and uncertain. We aimed to determine whether factoring in chronic kidney disease (CKD) will improve CV risk prediction in those with medium risk. This is a 10-year retrospective cohort study of 905 subjects in a primary care clinic setting. Baseline CV risk profile and serum creatinine in 1998 were captured from patients record. Framingham general cardiovascular disease risk score (FRS) for each patient was computed. All cardiovascular disease (CVD) events from 1998–2007 were captured. Overall, patients with CKD had higher FRS risk score (25.9% vs 20%, p = 0.001) and more CVD events (22.3% vs 11.9%, p = 0.002) over a 10-year period compared to patients without CKD. In patients with medium CV risk, there was no significant difference in the FRS score among those with and without CKD (14.4% vs 14.6%, p = 0.84) However, in this same medium risk group, patients with CKD had more CV events compared to those without CKD (26.7% vs 6.6%, p = 0.005). This is in contrast to patients in the low and high risk group where there was no difference in CVD events whether these patients had or did not have CKD. There were more CV events in the Framingham medium risk group when they also had CKD compared those in the same risk group without CKD. Hence factoring in CKD for those with medium risk helps to further stratify and identify those who are actually at greater risk, when treatment may be more likely to be indicated.

Elevated serum homocysteine is a predictor of accelerated decline in renal function and chronic kidney disease: A historical prospective study

OBJECTIVE

To estimate the effect of elevated serum homocysteine level on renal function decline and on the incidence of chronic kidney disease (CKD) in the general population.

METHODS

A historical prospective study on 3602 subjects attending a screening center in Israel between the years 2000 and 2012. Only subjects with normal estimated glomerular filtration rate (eGFR) and without proteinuria were included. Subjects were divided to two groups according to mean total serum homocysteine level (≤ 15, >15μmol/l). Linear mixed effect model was used to estimate the annual eGRF decline in respect to homocysteine group. Cox proportional hazards models were used to estimate hazard ratios for CKD in the normal compared to the elevated homocysteine group.

RESULTS

Annual eGFR decline was 25% higher in subjects with elevated versus normal mean homocysteine level (0.90 ± 0.16 ml/min/1.37 m(2) vs. 0.72 ± 0.14 ml/min/1.37 m(2), p<0.001). In a median follow up of 7.75 years, 38 subjects developed CKD (1.05%). Elevated mean homocysteine level was highly associated with developing CKD (HR 4.85, 95% CI 2.48-9.49, p<0.001). In a multivariate analysis which adjusted for age, baseline kidney function, HDL cholesterol, BMI, vitamin B12 and folic acid levels, these relationships remained substantially unchanged.

CONCLUSIONS

Elevated mean serum homocysteine level is associated with an accelerated decline in renal function in both men and women, and is an independent risk factor for the development of CKD in the general population. Further prospective randomized clinical trials are needed to clarify whether the reduction in serum homocysteine concentrations will result in an improved renal prognosis.

Clinical features of Chinese coronary heart disease patients with chronic kidney disease

OBJECTIVES

To investigate the prevalence of chronic kidney disease (CKD) by stage in Chinese patients with coronary heart disease (CHD) and to identify the clinical features and examine control of cardiovascular risk factors.

METHODS AND RESULTS

Clinical data of hospitalized patients were collected by investigators in China. CKD stages were classified according to estimated glomerular filtration rate (eGFR). A total of 2509 participants with CHD were included in the final statistical analysis. The overall prevalence of CKD stage 3 and greater (eGFR of less than 60 mL/min/1.73 m(2)) in the CHD patients was 32.5%. As the CKD stage increased, fasting blood glucose (FBG), systolic blood pressure (SBP), diastolic blood pressure (DBP), and high-sensitivity C-reactive protein (HS-CRP) levels all worsened. As the CKD stage became more severe, CHD patients had comorbidities such as diabetes mellitus, periphery arterial disease, and ischemic stroke, and more CHD patients had triple vessel disease increased. Even when patients received treatment of CHD and risk factors, control of cardiovascular risk factors such as SBP, DBP, FBG, and low-density lipoprotein was worsened as CKD stage became more severe over a 6-week follow-up.

CONCLUSIONS

The data suggested a high prevalence of CKD in Chinese patients with CHD. Many conventional risk factors and comorbidities were correlated with high prevalence of CKD in CHD patients. Control of cardiovascular risk factors in those patients was poor.

Risk factors of cardiovascular disease among children with chronic kidney disease in Gaza strip

Background:

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. Cardiovascular disease (CVD) is a major cause of mortality in patients with mild-to-moderate CKD and end-stage renal disease. There is accumulating evidence that the increase in CVD burden is present in CKD patients prior to dialysis, due both to conventional risk factors and kidney-specific disease. Detection and initiation of treatment for CVD risk factors at early stages of CKD should be effective in reducing CVD events before as well as after the onset of kidney failure.

Materials and Methods:

The study sample consisted of a total of 112 subjects aged ≤12 years: 60 CKD patients and 52 healthy control individuals. All subjects were investigated for a group of CVD risk factors such as: Hypertension, diabetes, dyslipidemia, physical inactivity, body mass index (BMI), family history of CVD, hypoalbuminemia, albuminuria, anemia, Ca x P product, and inflammation in terms of C-reactive protein (CRP).

Results:

Patients (40 males and 20 females) were categorized into four CKD stages (2, 3, 4, and 5) where, Stage 4 had the highest frequency, followed by Stages 3, 5 and 2. Evaluation of the patients indicated that they were shorter, had lower weight and had higher systolic and diastolic blood pressure as compared with control subjects. Frequency of physical inactivity among patients was two-fold higher than controls (50% vs. 25%). The patients showed significantly higher levels of cholesterol (163.6±39.8 vs. 141.8±24.2 mg/dL, P<0.0001), triglycerides (145.5±67.1 vs. 82.9±39.8 mg/dL, P<0.0001), low-density lipoprotein (92.6±31.9 vs. 72.5±19 mg/dL, P<</i>0.0001) and albumin/creatinine ratio (1792±3183 vs. 11.1±6.6 mg/g, P<0.0001). Moreover, the patients had lower levels of high-density lipoprotein (41.9±11.0 vs. 52.7±11.7 mg/dL, P<0.0001), hemoglobin (9.8±1.4 vs. 11.9±0.8 g/dL, P<0.0001) and albumin (4.6±0.6 vs. 4.8±0.2 g/dL, P=0.012). The CRP showed higher occurrence among patients (40% were positive for CRP). Calcium and phosphorus evaluation showed significantly lower calcium and higher phosphorus among patients. However, the difference in Ca X P product was not statistically significant.

Conclusions:

The study indicates that many of the CVD risk factors are associated with the different stages of CKD in children patients prior to dialysis, and that some of these factors are exacerbated as CKD progresses.

Measuring the population burden of chronic kidney disease: a systematic literature review of the estimated prevalence of impaired kidney function

BACKGROUND

Internationally, there have been substantial efforts to improve the early identification of chronic kidney disease (CKD), with a view to improving survival, reducing progression and minimizing cardiovascular morbidity and mortality. In 2002, a new and globally adopted definition of CKD was introduced. The burden of kidney function impairment in the population is unclear and widely ranging prevalence estimates have been reported.

METHODS

We conducted a systematic literature review, searching databases to June 2009. We included all adult population screening studies and studies based on laboratory or clinical datasets where the denominator was clear. Studies reporting prevalence estimates based on at least one eGFR <60 mL/min/1.73m(2) or elevated creatinine above a stated threshold were included. Study design and quality were explored as potential factors leading to heterogeneity.

RESULTS

We identified 43 eligible studies (57 published reports) for inclusion. Substantial heterogeneity was observed with estimated prevalence (0.6-42.6%). The included studies demonstrated significant variation in methodology and quality that impacted on the comparability of their findings. From the higher quality studies, the six studies measuring impaired kidney function (iKF) using estimated glomerular filtration rate in community screening samples reported a prevalence ranging from 1.7% in a Chinese study to 8.1% in a US study, with four reporting an estimated prevalence of 3.2-5.6%. Heterogeneity was driven by the measure used, study design and study population.

CONCLUSION

In the general population, estimated iKF, particularly eGFR 30-59 mL/min/1.73m(2) was common with prevalence similar to diabetes mellitus. Appropriate care of patients poses a substantial global health care challenge.

Circulating levels of asymmetric dimethylarginine are an independent risk factor for left ventricular hypertrophy and predict cardiovascular events in pre-dialysis patients with chronic kidney disease

BACKGROUND

Several studies have related the circulating level of asymmetric dimethylarginine (ADMA) to cardiac remodeling and cardiovascular (CV) events in end-stage renal disease (ESRD) patients. Studies investigating this relationship in patients with pre-dialysis chronic kidney disease (CKD) are lacking.

METHODS

We enrolled 76 CKD patients (age, 46.7+/-14.3 years, 39 females) and 15 controls (age, 40.1+/-18.5 years, 6 females). Clinical parameters, blood biochemistry and echocardiographic findings were recorded, and plasma ADMA concentrations measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Patients were prospectively followed up for a median of 15 (range, 6-24) months.

RESULTS

Plasma ADMA was significantly elevated in CKD patients compared with controls (41.56+/-12.76 microg/mL vs 17.12+/-7.09 microg/mL, P<0.001), and correlated with the left ventricular mass index (LVMI) (r=0.597, P<0.001). During follow-up, 25 patients experienced new CV events and their plasma ADMA level was significantly elevated (48.27+/-13.70 vs 34.91+/-6.38 in CV event-free patients, P<0.001). Cox regression analysis further confirmed that ADMA was an independent risk factor for CVD (HR=1.175, 95%CI[1.070-1.290], P=0.001).

CONCLUSION

Similar to findings in ESRD patients, elevated circulating levels of ADMA may increase the risk of LVH and CV events in pre-dialysis CKD patients.

Chronic kidney disease, all-cause mortality and cardiovascular mortality among Chinese patients with established cardiovascular disease

AIM

This study was conducted to investigate the role of chronic kidney disease (CKD) in 1-year all cause mortality and cardiovascular mortality among Chinese patients who were at least 50 years old and had a history of coronary artery disease (CAD), stroke, or peripheral vascular disease (PAD), or with two or more cardiovascular risks.

METHODS

Of 3,732 hospitalized patients enrolled, 3,423 patients (91.7%) with complete data were eligible for 1-year follow-up. CKD was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m(2).

RESULTS

1,166 (34.1%) were diagnosed with CKD. Most cases were unrecognized. Patients having an eGFR of <30 mL/min/1.73 m(2) were less likely to be prescribed beta-blockers, statins, or aspirin (all p<0.001). A powerful relationship was observed between the severity of renal dysfunction and all causes of death or cardiovascular death. Adjusted for other covariates, the hazard ratio (HR) for all causes of death and for cardiovascular death among patients with an eGFR of 30-45 mL/min/1.73 m(2) was 1.70 (95% CI, 1.18-2.45) and 1.85 (95% CI, 1.12-3.01) as compared with 2.93 (95% CI, 1.96-4.38) and 3.47 (95% CI, 1.91-6.31) for patients with an eGFR of <30 mL/min/1.73 m(2).

CONCLUSIONS

One third of Chinese patients at high risk for atherosclerotic events were diagnosed with CKD. Most of these cases were unrecognized and undertreated. An eGFR of <45 mL/min/1.73 m(2) was an independent predictor of all causes of death and of cardiovascular death.

Carotid endarterectomy benefits patients with CKD and symptomatic high-grade stenosis

Endarterectomy is generally recommended for symptomatic high-grade (70 to 99%) stenosis of the internal carotid artery, but whether this procedure is beneficial among patients with chronic kidney disease (CKD) is unknown. In this re-analysis of data from the North American Symptomatic Carotid Endarterectomy Trial, we included patients with symptomatic stenosis and either stage 3 CKD (n = 524) or preserved kidney function (n = 966; estimated GFR > or = 60). For medically treated patients with high-grade stenosis, risk for ipsilateral stroke at 2 yr was significantly higher in patients with CKD than in those with preserved renal function (31.6 versus 19.3%; P = 0.042); carotid endarterectomy significantly reduced this risk by 82 and 51%, respectively. To prevent one ipsilateral stroke, the number needed to treat by endarterectomy was four for patients with CKD and 10 for patients with preserved renal function. Compared with patients with preserved renal function, those with CKD had similar rates of perioperative stroke and death but higher rates of cardiac events. In conclusion, patients with stage 3 CKD and symptomatic high-grade carotid stenosis gain a large benefit in stroke risk reduction after endarterectomy.

Effect of repeated freeze-thaw cycles on urinary albumin-to-creatinine ratio

BACKGROUND

Urinary albumin-to-creatinine ratio (UACR) is widely used for diagnosis of chronic kidney disease in population investigation surveys. It is recommended that urinary albumin should be measured as soon as possible after urine is collected. It is not clear whether freezing and thawing affect the value of UACR and it is very inconvenient to measure UACR quickly in a population survey. The current study tries to determine the effect of repeated freezing and thawing on UACR to explore the possibility of freezing urine samples.

METHODS

Fifty-three urine samples with abnormal urinary albumin (ranging from 22.9 mg/L to 891.9 mg/L) were selected. The albumin and creatinine were measured before freezing, then all sample were stored at -30 degrees C. After being thawed at room temperature, the albumin and creatinine concentrations were measured again. The samples were frozen and thawed for five times, and albumin and creatinine were measured after each thawing. The measurements of albumin, creatinine, and UACR after each thawing were calculated and compared with its initial values using multiple comparisons of one-way ANOVA.

RESULTS

Compared with its initial value, urine albumin, creatinine and UACR all did not show any significant differences (p > 0.05).

CONCLUSIONS

It is feasible to freeze urine samples for future measurement of UACR. Urine samples can be safely frozen and thawed at least five times.

Efficacy of an intravenous proton pump inhibitor after endoscopic therapy with epinephrine injection for peptic ulcer bleeding in patients with uraemia: a case-control study

BACKGROUND

Patients with peptic ulcer bleeding and uraemia are prone to re-bleeding.

AIM

To compare the efficacy of an intravenous proton pump inhibitor in treating peptic ulcer bleeding in patients with uraemia and those without uraemia.

METHODS

High-risk peptic ulcer bleeding patients received endoscopic therapy with epinephrine (adrenaline) injection plus intravenous omeprazole (40 mg bolus followed by 40 mg infusion every 12 h) for 3 days. Re-bleeding, volume of blood transfusion, hospital stay, need for surgery, and mortality were analysed.

RESULTS

The uraemic group had similar 7-day re-bleeding rate (6/42, 14.29% vs. 6/46, 13.04%, P = 0.865) to that of non-uraemic patients, but more re-bleeding episodes beyond 7 days (4/42, 9.52% vs. 0/46, 0%, P = 0.032, OR [95% CI] = 1.105 [1.002-1.219]) and all-cause mortality (4/42 vs. 0/46 P = 0.032, OR [95% CI] = 1.105 [1.002-1.219]). The uraemic group also had more units of blood transfusion after endoscopic therapy (mean +/- s.d. 4.33 +/- 3.35 units vs. 2.15 +/- 1.65 units, P < 0.001), longer hospital stay (mean +/- s.d. 8.55 +/- 8.12 days vs. 4.11 +/- 1.60 days, P < 0.001) and complications during hospitalization (9/42 vs. 0/46, P = 0.001, OR [95% CI] = 1.273 [1.087-1.490]).

CONCLUSION

Endoscopic therapy with epinephrine injection plus an intravenous proton pump inhibitor can offer protection against early re-bleeding in uraemic patients with peptic ulcer bleeding, but has a limited role beyond 7 days.

Mortality risks for all causes and cardiovascular diseases and reduced GFR in a middle-aged working population in Taiwan

BACKGROUND

Effects of decreased estimated glomerular filtration rate (eGFR) on cardiovascular disease (CVD) mortality are uncertain in Chinese general populations.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

17,026 adults 50 years and older in Taiwan. A subset of 7,968 had repeated measurements.

PREDICTOR

Decreased eGFR and its progression. eGFR was calculated from serum creatinine level by using the Modification of Diet in Renal Disease Study equation.

OUTCOMES

Mortality from all causes and CVD, including coronary heart disease (CHD) and stroke, from the National Death Registry.

MEASUREMENTS

Hazard ratios (HRs) and Kaplan-Meier survival curves were calculated for participants with a moderate to severe decrease in eGFR (<60 mL/min/1.73 m(2)) compared with those with normal eGFR (> or =90 mL/min/1.73 m(2)). HR of a rapid decrease (> or =20%) in eGFR was also calculated.

RESULTS

Mean age of all participants was 57.2 +/- 5.2 (SD) years. We observed 1,682 deaths in 15 years of follow-up. Participants with a moderate to severe decrease in eGFR had increased HRs for mortality from all causes (1.44; 95% confidence interval [CI], 1.22 to 1.70), CVD (1.90; 95% CI, 1.36 to 2.65), CHD (2.07; 95% CI, 1.26 to 3.41), and stroke (2.16; 95% CI, 1.29 to 3.62) after adjusting for confounders. Decreased eGFR was associated with ischemic stroke, but not hemorrhagic stroke. No significant interaction between decreased eGFR and anemia, diabetes, or smoking was found. There were 660 participants with a 20% or greater decrease in eGFR from baseline during 18 months of follow-up. They had increased HRs for all causes (1.45; 95% CI, 1.13 to 1.86), CVD (2.48; 95% CI, 1.58 to 3.89), CHD (2.14; 95% CI, 1.07 to 4.29), and stroke (2.79; 95% CI, 1.45 to 5.36) compared with those with less than a 20% decrease in eGFR during the same period.

LIMITATIONS

Data for proteinuria were not available. Creatinine assay was not calibrated.

CONCLUSIONS

A moderate to severe or fast decrease in eGFR was associated with all-cause and CVD mortality in this ethnic Chinese cohort.

Gender differences in predictors of the decline of renal function in the general population

We sought to identify predictors of the decline in renal function, especially those that are modifiable, in the 5488 participants of the prospective, community-based cohort study PREVEND who completed three visits during a mean follow-up of 6.5 years. The change in renal function was used as the outcome and this was calculated as the linear regression of three estimated GFR measurements obtained during follow-up. Risk factors, known to influence renal outcome in patients with primary renal diseases, were used as potential predictors in multivariate regression analyses. High systolic blood pressure and plasma glucose were found to be independent predictors for an accelerated decline in function for both genders. In males, albuminuria was the strongest independent predictor for renal function decline, whereas in females albuminuria was univariately associated only after adjustment for age. The direction of the association between cholesterol/HDL ratio and decline of renal function differed by gender. Surprisingly, in males, waist circumference was an independent predictor and positively associated with renal function outcome. These studies show that there are gender differences in the standard predictors of the decline in renal function.

An association between the estimated glomerular filtration rate and carotid atherosclerosis

OBJECTIVE

Chronic kidney disease (CKD) is a major public health problem. There is conflicting evidence concerning whether CKD is an independent risk factor for carotid intima-media thickness (IMT).

PATIENTS AND METHODS

The study subjects were 428 men aged 70+/-15 (mean+/-standard deviation) years and 582 women aged 75+/-12 years enrolled consecutively from patients in the Medical Department of Seiyo Municipal Nomura Hospital. Carotid IMT was derived via B-mode ultrasonography and CKD was evaluated by the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study equation.

RESULTS

In men, age (p<0.001), systolic blood pressure (p<0.001), antihypertensive drug use (p<0.001), HDL-C (p=0.006), LDL-C (p=0.004), prevalence of diabetes (p=0.035) and eGFR (p<0.001) were significantly correlated with carotid IMT. In women, age (p<0.001), systolic blood pressure (p<0.001), antihypertensive drug use (p<0.001), HDL-C (p=0.035), LDL-C (p=0.017) and eGFR (p<0.001) were significantly correlated with carotid IMT. Stepwise multiple linear regression analysis using IMT as an objective variable, adjusted by various factors as explanatory variables, showed that eGFR was a significant independent contributing factor along with known risk factors in men (beta, -0.096; p=0.018) and women (beta, -0.080; p=0.035).

CONCLUSIONS

Our data suggested that eGFR was associated with an increased prevalence of carotid atherosclerosis independent of common cardiovascular risk factors in both men and women.

Performance and comparison of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease formulae in estimating glomerular filtration rate in a Chinese Type 2 diabetic population

AIMS

Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks.

METHODS

A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared.

RESULTS

The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks.

CONCLUSIONS

These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks.

Chronic kidney disease as a risk factor for coronary artery disease in Chinese with type 2 diabetes

BACKGROUND

Chronic kidney disease (CKD) is associated with cardiovascular disease (CVD) in the general population. We investigated the effects of renal function on coronary artery disease (CAD) in Chinese with type 2 diabetes who have a high risk of developing diabetic nephropathy but who may have a low risk of developing CAD.

METHODS

We recruited a total of 2,434 Chinese with type 2 diabetes (1,078 men and 1,356 women) and diagnosed CAD by history or with an abnormal electrocardiogram (coronary probable or possible by Minnesota codes). Renal function was evaluated by serum creatinine (SCr) levels, estimated glomerular filtration rate (eGFR) (calculated by the abbreviated Modification of Diet in Renal Disease Study Croup formula) and urinary albumin/creatinine ratio (ACR).

RESULTS

We found that patients with CAD were older, had higher SCr levels and body mass index (BMI), and had lower serum high-density lipoprotein cholesterol (HDL-c) levels. After adjusting for age, BMI, blood pressure, glycosylated hemoglobin, cholesterol, LDL-c, HDL-c, and triglycerides, we found that SCr levels >1.5 mg/dl, eGFR <60 ml/min, and urinary ACR >30 mg/g were independent risk factors for CAD in diabetic men, and that SCr levels >1.4 mg/dl and eGFR <60 ml/min were independently associated with CAD in women.

CONCLUSION

Our findings indicate that Chinese with type 2 diabetes and CKD are likely to have had CAD previously and CKD is 'CVD risk state' in diabetic Chinese.

Improved GFR estimation by combined creatinine and cystatin C measurements

Plasma creatinine may not reflect glomerular filtration rate (GFR) especially in the early stages of chronic kidney disease (CKD). Plasma cystatin C (cysC), however, has the potential to more accurately determine early GFR reduction. We sought to improve the creatinine-based GFR estimation by including cysC measurements. We derived a reference GFR from standard dual plasma sampling (99m)Tc-DTPA clearance in a training cohort of 376 randomly selected adult Chinese patients with CKD. We compared reference values to estimated GFR and applied multiple regression models to one equation based solely on cysC, and to another combining plasma creatinine (Pcr) and cysC measurements of the training cohort. The results were validated by testing an additional 191 patients. The difference, precision, and accuracy of the two estimates were compared with the modified Modification of Diet in Renal Disease (MDRD) equation for Chinese patients, and another estimate combining cysC and modified MDRD calculations. The estimated GFR combining Pcr and cysC measurements more accurately matched the reference GFR at all stages of CKD than the other equations, particularly in patients with near-normal kidney function.

Epidemiology, major outcomes, risk factors, prevention and management of chronic kidney disease in China

Chronic kidney disease (CKD) is common in China. In residents older than 40 years in Beijing, China, 11.3% of subjects had at least one indicator of kidney damage. The primary cause of chronic renal failure in China was glomerulonephritis, which was followed by diabetic nephropathy and hypertensive nephrosclerosis. Renal failure, cardiovascular disease and infection were important complications. IgA nephropathy (IgAN) is the most common CKD in China. The prevalence of hypertension, intrarenal artery lesions and tubulointerstitial lesions in patients with IgAN at the time of renal biopsy was approximately 40, 55 and 85%, respectively. The genetic variation in Megsin confers susceptibility to IgAN in Chinese. The patients with SL/LL genotypes of the MUC20 gene, the 38AA genotype of uteroglobin and DD genotype of the angiotensin-converting enzyme gene had a higher risk of progression. Chinese prospective clinical trials showed that benazepril (BZ) conferred substantial renal benefits in patients with advanced renal insufficiency. The combined therapy with urokinase and BZ was more effective than with BZ alone in reducing proteinuria and protecting renal function in Chinese patients with severe IgAN. Lupus nephritis (LN) is a common form of secondary renal disease diagnosed by renal biopsy in China. Chinese multicenter clinical trials showed that mycophenolate mofetil or leflunomide combined with steroids was effective as induction therapy for proliferative LN.

Recurrence of peptic ulcer in uraemic and non-uraemic patients after Helicobacter pylori eradication: a 2-year study

BACKGROUND

The role of Helicobacter pylori in the pathogenesis of peptic ulcer disease in patients with uraemia remains unclear.

AIM

To evaluate the long-term effect of H. pylori eradication in these patients.

METHODS

Uraemic and non-uraemic patients with peptic ulcer were enrolled in this study. Patients having history of non-steroidal anti-inflammatory drugs use or cardiovascular disease that need aspirin use were excluded. After confirmation of H. pylori infection, they received a triple therapy and were followed up for 2 years.

RESULTS

Between September 1999 and December 2005, 34 patients (41%) of the end-stage renal disease [H. pylori (+) group] and 67 (84%) of the non-uraemic patients with peptic ulcer disease (PU group) received anti-H. pylori therapy. After triple therapy, 32 (94%) from the end-stage renal disease group and 64 (96%) from the peptic ulcer group obtained successful eradication. During the 2-year follow-up, three patients in the end-stage renal disease group were excluded because of the presence of cardiovascular disease and aspirin use in two cases and died of heart failure in one case; two patients in peptic ulcer group refused follow-up. Finally, 29 uraemic and 62 non-uraemic patients had achieved the follow-up. Recurrence of peptic ulcer was more in the end-stage renal disease group than in the peptic ulcer group with intention-to-treat analysis (eight of 32, 25% vs. two of 64, 3%, P = 0.001, OR: 10.0, 95% CI: 1.979-50.540) or per-protocol analysis (eight of 29, 28% vs. two of 62, 3%, P < 0.001, OR: 11.4, 95% CI: 2.245-58.168).

CONCLUSIONS

Peptic ulcer recurrence after H. pylori eradication is higher in end-stage renal disease patients with peptic ulcer than in peptic ulcer patients without renal disease. Factors aside from H. pylori play an important role in peptic ulcer recurrence in end-stage renal disease patients.

Metabolic syndrome and chronic kidney disease in a Chinese population aged 40 years and older

OBJECTIVE

To explore the relationship between metabolic syndrome and chronic kidney disease (CKD) in a study population from a developing country.

PARTICIPANTS AND METHODS

The prevalence of metabolic syndrome (as most recently defined by the International Diabetes Federation) and CKD (defined as an estimated glomerular filtration rate of < 60 mL/min per 1.73 m2 and/or albuminuria) was determined in 2310 study participants (age > or =40 years) from Beijing, China, between May 12 and December 7, 2004. The relationship between metabolic syndrome and CKD was then analyzed.

RESULTS

Participants with metabolic syndrome had a higher prevalence of CKD (15.4% vs 8.3%; P<.001) than those without the syndrome. As the number of metabolic syndrome traits increased, so did the prevalence of CKD. Strong unadjusted and adjusted associations were observed between metabolic syndrome and CKD. For participants without hypertension and diabetes, metabolic syndrome was also associated with CKD (odds ratio, 2.03; 95% confidence interval, 1.05-3.94).

CONCLUSIONS

In these 2310 Chinese study participants aged 40 years and older, metabolic syndrome was associated with CKD.

Association Between Carotid Artery Intima-Media Thickness and Early-Stage CKD in a Chinese Population

BACKGROUND

Increased carotid artery intima-media thickness (IMT) predicts future vascular events in the general population. However, the relationship between IMT and chronic kidney disease (CKD) seldom was tested in subjects with early-stage CKD.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

1,046 residents in 1 district of Beijing participated in the study.

OUTCOMES & MEASUREMENTS

Carotid artery IMT was measured by means of high-resolution B-mode ultrasonography. Estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease Study equation based on data for Chinese patients with CKD. Albuminuria was evaluated by means of urinary albumin-creatinine ratio on a morning spot urine sample.

RESULTS

Compared with subjects with eGFR greater than 90 mL/min/1.73 m(2) (>1.50 mL/s/1.73 m(2)), subjects with eGFR of 60 to 89 mL/min/1.73 m(2) (1.00 to 1.49 mL/s/1.73 m(2)) and 30 to 59 mL/min/1.73 m(2) (0.50 to 0.99 mL/s/1.73 m(2)) had higher mean IMT (0.74 +/- 0.27 versus 0.82 +/- 0.30 versus 0.94 +/- 0.38 mm; P < 0.001). IMTs of subjects with albuminuria tended to be higher than the mean value (0.79 +/- 0.29 versus 0.93 +/- 0.38 mm; P < 0.001). eGFR and urinary albumin-creatinine ratio significantly correlated with IMT in univariable analysis, but not after adjusting for traditional cardiovascular disease risk factors.

LIMITATIONS

Selection bias and low prevalence of CKD might affect the strength of the study.

CONCLUSIONS

In this Chinese population older than 40 years, carotid artery IMT was significantly higher in subjects with early-stage CKD. The greater prevalence of cardiovascular disease risk factors in patients with CKD appeared to account for the higher carotid artery IMT.