Cardio-Kidney-Damage: a unifying concept

Vasculopathy Augments Cardiovascular Risk in Community-Dwelling Elderly with Left Ventricular Hypertrophy

This study aimed to investigate the impact of various vasculopathies alongside left ventricular hypertrophy (LVH) on cardiovascular risk in the elderly. This prospective cohort study included 3339 older adults from the Northern Shanghai Study, classified into four mutually exclusive left ventricular (LV) geometry groups based on echocardiographic data: normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Vasculopathy was categorized into three primary types: arteriosclerosis, atherosclerosis, and renal senescence. Major adverse cardiovascular events (MACEs) were defined as non-fatal acute myocardial infarction, non-fatal stroke, and cardiovascular deaths according to ICD-10 codes. Over a median follow-up period of 5.7 years, 221 incident cases of MACEs were identified. Concentric hypertrophy exhibited the highest prevalence of hypertension, the most significant increase in vascular stiffness, and the highest rate of MACEs. The adjusted Cox regression analysis showed that eccentric hypertrophy is associated with an increased risk of MACEs (HR: 1.638 [95% CI: 1.151-2.331], p = 0.006), while concentric hypertrophy shows an even higher risk (HR: 1.751 [95% CI: 1.127-2.721], p = 0.013). Conversely, concentric remodeling was not significantly associated with an increased risk of MACEs. Renal senescence presents a moderate but significant risk for MACEs, with an HR of 1.361 (95% CI: 1.019-1.819; p = 0.037) when adjusted for LVH. The Kaplan-Meier analysis showed that patients with LVH and multiple vasculopathies experience the most significant decrease in survival probability (log-rank p < 0.001). The subgroup analysis revealed that LVH significantly raises the risk of MACEs, especially in older males with hypertension, diabetes, or vasculopathy. This study reinforces the importance of LVH as a predictor of adverse cardiovascular outcomes and underscores the compounded risk associated with the presence of multiple vasculopathies. Additionally, it highlights renal senescence as a distinct and independent risk factor for MACEs, separate from LVH.

Albuminuria as a predictor of mortality in type II diabetic patients after living-donor liver transplantation

PURPOSE

Diabetes mellitus (DM) increases the risk of morbidity and mortality after liver resection. Albuminuria is associated with a higher risk for all-cause and cardiovascular mortality. This study evaluated albuminuria as a predictor of the outcome of living donor liver transplantation (LDLT) in patients with pre-existing DM.

METHODS

This retrospective study involved 103 type II diabetic patients with end-stage liver disease who received LDLT. Preoperative spot urine albumin: creatinine ratio was used to determine the degree of albuminuria. The primary outcome measure was the impact of urinary albumin excretion on the 3-year mortality rate after LDLT in this diabetic cohort.

RESULTS

Hepatitis C virus infection was the main cause of cirrhosis. Albuminuria was detected in 41 patients (39.8%); 15 had macroalbuminuria, while 26 had microalbuminuria. Patients with microalbuminuria were significantly older than those with macroalbuminuria and normal albumin in urine. After 3 years, twenty-four patients (23.3%) died within 3 years after LT. Myocardial infarction was the leading cause of death (25%). Albuminuria was an independent factor affecting 3-year mortality with an odds ratio of 5.17 (95% CI: 1.86-14.35).

CONCLUSION

Preoperative albuminuria is an independent factor affecting mortality within 3 years after LDLT in type II diabetic patients. Myocardial infarction was the leading cause of death in 25% of cases, followed by hepatocellular carcinoma recurrence, sepsis, and graft failure.KEY MESSAGESDiabetes mellitus (DM) increases the risk of morbidity and mortality after liver resection.Albuminuria is associated with a higher risk for all-cause and cardiovascular mortality.Preoperative albuminuria is a significant predictor of mortality within 3 years after LDLT in diabetic patients.

Life course pathways from parental education to age-related decrements in kidney function among Black and white American adults

OBJECTIVE

Using cross-sectional data on Black and white adults, this analysis examined whether age-related decrements in kidney function across adulthood were associated with parental education, and whether the association was differentially influenced by race. Further, this study assessed racial differences in life course pathways from parental education to age-related decrements in kidney function, through current SES and health-related risk factors.

METHOD

Data from the main survey and the Biomarker Project of the Midlife in the United States (MIDUS) Wave 2 and Refresher samples were combined, resulting in 1861 adults (54.5% female; age 25-84, Mage = 53.37) who self-identified as non-Hispanic Black (n = 326) and non-Hispanic white (n = 1535). Estimated glomerular filtration rate (eGFR) was based on serum creatinine, calculated using the CKD-EPI formula. Adults SES was based on education, income, and financial strains. Health-related risk factors included obesity, elevated blood pressure (BP), and insulin resistance. Hypotheses were tested by utilizing multiple linear regression and regression-based moderated mediation analysis.

RESULTS

Lower parental education was associated with steeper age-related decrements in eGFR (B = 0.38, SE = 0.15, p = .013, 95%CI = 0.08, 0.68), due to higher eGFR among younger participants and lower eGFR among older participants. In addition, age-related decrements in kidney function were steeper among Black relative to white adults (B = 0.41, SE = 0.13, p < .01, 95%CI = 0.16, 0.66), driven by higher proportion of younger Black adults that met criterion for renal hyperfiltration. Furthermore, parental education and race were associated with age-related decrements in kidney function in an additive rather than interactive way. There were some racial differences in the life course pathways from parental education to age-related differences in eGFR, glucoregulation, and hypertension. Among Black adults, lower parental education was associated with elevated eGFR among younger participants through insulin resistance. Among white adults, lower parental education was linked to higher eGFR among younger adults and lower eGFR among older adults, and the association was mediated by current SES, elevated BP, and insulin resistance.

DISCUSSION

Early life SES can have a long-lasting influence on the preclinical renal senescence that is associated with the normal biology of aging for both Black and white adults.

Genetic inhibition of FABP4 attenuated endoplasmic reticulum stress and mitochondrial dysfunction in rhabdomyolysis-induced acute kidney injury

AIMS

Rhabdomyolysis-associated acute kidney injury (AKI) is life-threatening but effective treatments is lacking. Recently, fatty acid-binding protein 4 (FABP4) has been identified as a mediator of ischemic and toxic AKI through regulating endoplasmic reticulum (ER) stress in our previous studies. However, the role of FABP4 in rhabdomyolysis-induced AKI and extended organelle dysfunctions need to be explored and validated.

MAIN METHODS

We firstly performed mRNA-seq and bioinformatic analysis to investigate the role of FABP4. The mouse model was established via injecting glycerol to FABP4 wild type (WT) and knockout (KO) mice. Blood biochemical, inflammatory and apoptotic parameters were measured and compared across groups. Representative pathways of ER stress and mitochondrial dysfunction were also detected and quantified.

KEY FINDINGS

Comparing FABP4 WT and FABP4 KO model groups, FABP4 deficiency significantly attenuated renal dysfunction, by reducing serum creatinine (165.90 ± 15.61 μmol/L vs 35.5 ± 8.33 μmol/L, p < 0.0001) and blood urea nitrogen (89.78 ± 6.82 mmol/L vs 19.75 ± 5.97 mmol/L, p < 0.0001), and alleviating tubular injury scores. Inflammatory and apoptotic responses were alleviated by FABP4 genetic inhibition. Mechanistically, glycerol injection triggered ER stress characterized by activated IRE1, PERK, and ATF6 signaling pathways, and induced mitochondrial dysfunction supported by ultrastructural damage, energy metabolic derangement, and excessive mitochondrial fission (upregulated DRP1/downregulated OPA1). These two organelle dysfunctions were effectively relieved by FABP4 deficiency.

SIGNIFICANCE

Taken together, genetic inhibition of FABP4 protected against rhabdomyolysis-induced AKI via reducing ER stress as well as mitochondrial dysfunction. FABP4 might act as a novel therapeutic target in rhabdomyolysis-induced AKI.

Prognostic value of estimated glomerular filtration rate and presence of proteinuria in type B aortic intramural hematoma

Background

Although aggressive medical treatment is recommended in patients with type B aortic intramural hematoma (IMH), a variety of aortic events can occur during the later period. For early identification of these patients, the present study was aimed at evaluating the prognostic validity of estimated glomerular filtration rate (eGFR) and the presence of proteinuria in type B aortic IMH.

Methods

Data of 61 patients with type B IMH in Peking University People's Hospital from January 2008 to December 2018 were retrospectively collected. The serum creatinine level and urine protein levels were measured at admission. And eGFR were calculated by the CKD-EPI equation. Adverse aortic-related events were defined as a composite of satisfaction of criteria for surgical conversion (with or without actual surgical intervention) and death from aortic rupture.

Results

Initial eGFR was significantly different between patients with adverse aortic-related events and those without (P=0.003). On multivariate analysis, eGFR <90 mL/min/1.73 m² (OR, 8.726; 95% CI: 1.711-46.144; P=0.009) and ULP (OR, 17.516; 95% CI: 3.322-92.258; P=0.001) were independent predictors of adverse aorta-related events. Furthermore, eGFR <90 mL/min/1.73 m² and proteinuria (+) (OR, 8.344; P=0.030) had significantly greater rates of aortic-related events. In addition, eGFR <90 mL/min/1.73 m² and proteinuria (+) had incremental prognostic value (C-statistic, 0.860, P=0.039) compared with ulcer-like projection (C-statistic, 0.815) alone.

Conclusions

Initial eGFR and presence of proteinuria were able to provide incremental prognostic information in addition to ulcer-like projection in patients with type B aortic IMH.

Association of proteinuria with incident atrial fibrillation in the general Japanese population

BACKGROUND

Although proteinuria has been associated with incident atrial fibrillation (AF) in Western countries, the association has not been investigated in the general Japanese population.

METHODS

Participants aged ≥40 years who underwent the Japanese specific health check-up in Kanazawa City in 2013 and who completed a urine dipstick test were included in this study. Exposure was considered as presence or absence of proteinuria (≥1+). The outcome was incident AF confirmed by 12-lead electrocardiography. The Cox proportional hazard model was used to compute hazard ratio (HR) of proteinuria (≥1+) for incident AF after adjustment for traditional risk factors. We also completed stratified analyses by baseline characteristics.

RESULTS

A total of 37,910 participants aged ≥40 years were included (mean age: 72.3 years, male sex: 37%). Proteinuria ≥1+ was observed in 2.765 (7.3%) participants. During a median follow-up period of 5 years, 708 incident AF cases were observed. Proteinuria ≥1+ was associated with incident AF (HR, 1.47: 95% confidence interval, 1.18-1.84) after covariate adjustment. Stratified analysis demonstrated that the association of proteinuria with AF was stronger in participants <75 years [HR 1.89 (95% CI 1.32-2.70)] compared with those ≥75 years [HR 1.27 (95% CI 0.95-1.69)] (interaction p-value=0.02).

CONCLUSIONS

Proteinuria was significantly associated with incident AF in the general Japanese population. The evaluation of proteinuria using urine dipstick test may be useful in the evaluation of incident AF, especially in younger general population.

A higher level of serum furin indicates a higher risk of microalbuminuria: results from a longitudinal study in Chinese adults

BACKGROUND

Furin, a key enzyme of natriuretic peptide system, has been suggested to play a role in microalbuminuria, but the association between furin and microalbuminuria has been scarcely studied.

METHODS

Leveraging a longitudinal cohort of Chinese adults who had urinary albumin measured twice 4 years apart, we examined the cross-sectional and prospective associations of baseline serum furin with microalbuminuria, adjusting for age, sex, education level, smoking, drinking, obesity, blood pressure, glucose, lipids, and antihypertensive medications.

RESULTS

The cross-sectional analysis in 2175 participants (53 ± 10 years, 38% men) found that a 10-time higher level of serum furin was significantly associated with a 64% higher risk of having microalbuminuria (OR = 1.64, P = 0.005). The longitudinal analysis found a positive association between baseline serum furin and dynamic elevation of albumin excretion during follow-up. The prospective analysis in 1357 participants free of microalbuminuria at baseline found that a 10-time higher level of serum furin at baseline was significantly associated with a 1.28-time higher risk of developing microalbuminuria 4 years later (OR = 2.28, P < 0.001).

CONCLUSIONS

A higher level of serum furin at baseline predicted an increased risk of developing microalbuminuria in Chinese adults. These findings indicate that furin might be a predictor or a risk factor for microalbuminuria but the causality still needs more investigations.

Role of Fatty Acid Binding Protein 4 (FABP4) in Kidney Disease

Accumulating evidences indicated that obesity and metabolic syndrome were independent risk factors for the development and progression of kidney diseases. Apart from inflammation, lipotoxicity, and hemodynamic factors, adipokines have been proposed to play crucial roles in the relationship between kidney diseases and metabolic disorders. As one of the key adipokines, fatty acid binding protein 4 (FABP4), which is mainly expressed in adipocytes and macrophages, has recently been shown to be associated with renal dysfunction and kidney damage. Both clinical and experimental studies have proposed circulating FABP4 as a novel predictor for renal injuries, and it might also be a predictor for cardiovascular events in patients with end stage renal disease (ESRD). FABP4 has also been detected in the glomerular cells and epithelial tubular cells in mouse and human kidneys, and the expression of FABP4 in these cells has been involved in the pathogenesis of kidney diseases. In addition, experimental studies suggested that inhibition of FABP4 had protective effects on renal damage. Here, we reviewed current knowledge regarding the role of FABP4 in pathophysiological insights as well as its potential function as a predictor and therapeutic target for kidney diseases.

Association of blood pressure with clinical outcomes in older adults with chronic kidney disease

BACKGROUND

in chronic kidney disease (CKD), hypertension is associated with poor outcomes at ages <70 years. At older ages, this association is unclear. We tested 10-year mortality and cardiovascular outcomes by clinical systolic blood pressure (SBP) in older CKD Stages 3 and 4 patients without diabetes or proteinuria.

METHODS

retrospective cohort in population representative primary care electronic medical records linked to hospital data from the UK. CKD staged by CKD-EPI equation (≥2 creatinine measurements ≥90 days apart). SBPs were 3-year medians before baseline, with mean follow-up 5.7 years. Cox competing models accounted for mortality.

RESULTS

about 158,713 subjects with CKD3 and 6,611 with CKD4 met inclusion criteria. Mortality increased with increasing CKD stage in all subjects aged >60. In the 70 plus group with SBPs 140-169 mmHg, there was no increase in mortality, versus SBP 130-139. Similarly, SBPs 140-169 mmHg were not associated with increased incident heart failure, stroke or myocardial infarctions. SBPs <120 mmHg were associated with increased mortality and cardiovascular risk. At ages 60-69, there was increased mortality at SBP <120 and SBP >150 mmHg.Results were little altered after excluding those with declining SBPs during 5 years before baseline, or for longer-term outcomes (5-10 years after baseline).

CONCLUSIONS

in older primary care patients, CKD3 or 4 was the dominant outcome predictor. SBP 140-169 mmHg having little additional predictive value, <120 mmHg was associated with increased mortality. Prospective studies of representative older adults with CKD are required to establish optimum BP targets.

Neutrophil Elastase Inhibitors and Chronic Kidney Disease

End-stage renal disease (ESRD), the last stage of chronic kidney disease (CKD), is characterized by chronic inflammation and oxidative stress. Neutrophils are the front line cells that mediate an inflammatory response against microorganisms as they can migrate, produce reactive oxygen species (ROS), secrete neutrophil serine proteases (NSPs), and release neutrophil extracellular traps (NETs). Serine proteases inhibitors regulate the activity of serine proteases and reduce neutrophil accumulation at inflammatory sites. This review intends to relate the role of neutrophil elastase in CKD and the effects of neutrophil elastase inhibitors in predicting or preventing inflammation.

Associations Between Kidney Disease Measures and Regional Pulse Wave Velocity in a Large Community-Based Cohort: The Atherosclerosis Risk in Communities (ARIC) Study

RATIONALE & OBJECTIVE

Arterial stiffness is suggested as a mediator of cardiorenal interaction. However, previous studies reported inconsistent associations between chronic kidney disease (CKD) and arterial stiffness and were limited by using either estimated glomerular filtration rate (eGFR) or albumin-creatinine ratio (ACR) and examining arterial stiffness at limited segments.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

3,424 Atherosclerosis in Communities (ARIC) Study participants aged 66 to 90 years during 2011 to 2013.

PREDICTORS

eGFR and ACR.

OUTCOME

Pulse wave velocity (PWV) at 6 segments: carotid-femoral (cfPWV), heart-carotid (hcPWV), and heart-femoral (hfPWV), reflecting central stiffness; heart-ankle (haPWV) and brachial-ankle (baPWV), representing both central and peripheral stiffness; and femoral-ankle (faPWV), indicating peripheral stiffness.

ANALYTICAL APPROACH

Multiple linear and logistic regression models to quantify the associations of eGFR and ACR with continuous PWV and elevated PWV (in the highest quartile), respectively.

RESULTS

After adjusting for age, sex, and race, higher cfPWV and hfPWV were consistently associated with lower eGFR and higher ACR. Higher haPWV and baPWV were also observed with higher ACR. The independent association of both CKD measures with elevated cfPWV remained consistent after adjusting for additional confounders (ORs of elevated cfPWV were 1.09 [95% CI, 1.01-1.18] per 15-mL/min/1.73m² lower eGFR and 1.20 [95% CI, 1.07-1.33] per 4-fold higher ACR). Higher ACR was also associated with elevated hfPWV and haPWV (ORs per 4-fold higher ACR were 1.25 [95% CI, 1.12-1.39] for elevated hfPWV and 1.19 [95% CI, 1.06-1.33] for elevated haPWV). Lower eGFR was associated with lower odds of elevated baPWV and faPWV (ORs per 15-mL/min/1.73m² lower eGFR were 0.92 [95% CI, 0.84-0.99] and 0.91 [95% CI, 0.85-0.99], respectively).

LIMITATION

Unable to address temporality between CKD measures and arterial stiffness.

CONCLUSIONS

Both lower eGFR and higher ACR are independently associated with measures of central arterial stiffness, with stronger associations for ACR over eGFR. Our findings suggest that central arterial stiffness may be an important pathophysiologic phenotype of vascular disease in CKD.

Risk factors for increased left ventricular hypertrophy in patients with chronic kidney disease: findings from the CKD-JAC study

Background

Although left ventricular hypertrophy (LVH) has been established as a predictor of cardiovascular events in chronic kidney disease (CKD), the relationship between the prevalence of LVH and CKD stage during the pre-dialysis period has not been fully examined.

Methods

We measured left ventricular mass index (LVMI) in a cross-sectional cohort of participants in the Chronic Kidney Disease Japan Cohort (CKD-JAC) study to identify factors that are associated with increased LVMI in patients with stage 3–5 CKD.

Results

We analyzed the baseline characteristics in 1088 participants (male 63.8%, female 36.2%). Diabetes mellitus was the underlying disease in 41.7% of the patients, and mean age was 61.8 ± 11.1 years. LVH was detected in 23.4% of the patients at baseline. By multivariate logistic analysis, independent risk factors for LVH were past history of cardiovascular disease [odds ratio (OR) 2.364; 95% confidence interval ([CI) 1.463–3.822; P = 0.0004], body mass index (OR 1.108; 95% CI 1.046–1.173; P = 0.0005), systolic blood pressure (OR 1.173; 95% CI 1.005–1.369; P = 0.0433), urinary albumin (OR 1.425; 95% CI 1.028–1.974; P = 0.0333), and serum total cholesterol level (OR 0.994; 95% CI 0.989–0.999; P = 0.0174).

Conclusion

The cross-sectional baseline data from the CKD-JAC study shed light on the association between LVH and risk factors in patients with decreased renal function. Further longitudinal analyses of the CKD-JAC cohort are needed to evaluate the prognostic value of LVH in CKD patients.

Kidney Disease Measures and Left Ventricular Structure and Function: The Atherosclerosis Risk in Communities Study

Background

Heart failure is one of the most important complications of chronic kidney disease (CKD). However, few studies comprehensively investigated left ventricular (LV) structure and function in relation to 2 key CKD measures, estimated glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (ACR).

Methods and Results

Among 4175 ARIC (Atherosclerosis Risk in Communities) participants (aged 66–90 years during 2011–2013), we quantified the association of eGFR and ACR with echocardiogram parameters of LV mass, size, systolic function, and diastolic function. Adjusting for demographic variables, both CKD measures were significantly associated with most echocardiogram parameters. Additionally accounting for other potential confounders, we observed significantly higher LV mass index according to reduced eGFR (82.3 [95% confidence interval (CI), 77.6–87.0] g/m² for eGFR <30 mL/min per 1.73 m², 80.9 [95% CI, 77.3–84.6] g/m² for eGFR 30–44 mL/min per 1.73 m², and 80.1 [95% CI, 76.7–83.5] g/m² for eGFR 45–59 mL/min per 1.73 m² compared with 78.7 [95% CI, 75.3–82.1] g/m² for eGFR 75–89 mL/min per 1.73 m²; trend P<0.001). Regarding LV size and function, significant differences were observed for some parameters, particularly at eGFR <30 mL/min per 1.73 m². For ACR, the associations remained significant for most parameters (eg, LV mass index, 91.5 [95% CI, 86.6–96.5] g/m² for ACR ≥300 mg/g and 82.9 [95% CI, 79.4–86.3] g/m² for ACR 30–299 mg/g compared with 77.7 [95% CI, 74.4–81.1] g/m² for ACR <10 mg/g [trend P<0.001]; left arterial volume index, 24.9 [95% CI, 22.9–26.8] and 24.7 [95% CI, 23.4–26.1] mL/m² compared with 23.4 [95% CI, 22.1–24.7] mL/m², respectively [trend P=0.010]). Dichotomizing echo parameters with clinical thresholds, the stronger relationships of ACR over eGFR were further evident.

Conclusions

LV mass was related to both CKD measures, whereas LV size and function were robustly associated with albuminuria. These results have implications for pathophysiological processes behind cardiorenal syndrome and targeted cardiac assessment in patients with CKD.

Measures of chronic kidney disease and risk of incident peripheral artery disease: a collaborative meta-analysis of individual participant data

BACKGROUND

Some evidence suggests that chronic kidney disease is a risk factor for lower-extremity peripheral artery disease. We aimed to quantify the independent and joint associations of two measures of chronic kidney disease (estimated glomerular filtration rate [eGFR] and albuminuria) with the incidence of peripheral artery disease.

METHODS

In this collaborative meta-analysis of international cohorts included in the Chronic Kidney Disease Prognosis Consortium (baseline measurements obtained between 1972 and 2014) with baseline measurements of eGFR and albuminuria, at least 1000 participants (this criterion not applied to cohorts exclusively enrolling patients with chronic kidney disease), and at least 50 peripheral artery disease events, we analysed adult participants without peripheral artery disease at baseline at the individual patient level with Cox proportional hazards models to quantify associations of creatinine-based eGFR, urine albumin-to-creatinine ratio (ACR), and dipstick proteinuria with the incidence of peripheral artery disease (including hospitalisation with a diagnosis of peripheral artery disease, intermittent claudication, leg revascularisation, and leg amputation). We assessed discrimination improvement through c-statistics.

FINDINGS

We analysed 817 084 individuals without a history of peripheral artery disease at baseline from 21 cohorts. 18 261 cases of peripheral artery disease were recorded during follow-up across cohorts (median follow-up was 7·4 years [IQR 5·7-8·9], range 2·0-15·8 years across cohorts). Both chronic kidney disease measures were independently associated with the incidence of peripheral artery disease. Compared with an eGFR of 95 mL/min per 1·73 m2, adjusted hazard ratios (HRs) for incident study-specific peripheral artery disease was 1·22 (95% CI 1·14-1·30) at an eGFR of 45 mL/min per 1·73 m2 and 2·06 (1·70-2·48) at an eGFR of 15 mL/min per 1·73 m2. Compared with an ACR of 5 mg/g, the adjusted HR for incident study-specific peripheral artery disease was 1·50 (1·41-1·59) at an ACR of 30 mg/g and 2·28 (2·12-2·44) at an ACR of 300 mg/g. The adjusted HR at an ACR of 300 mg/g versus 5 mg/g was 3·68 (95% CI 3·00-4·52) for leg amputation. eGFR and albuminuria contributed multiplicatively (eg, adjusted HR 5·76 [4·90-6·77] for incident peripheral artery disease and 10·61 [5·70-19·77] for amputation in eGFR <30 mL/min per 1·73 m2 plus ACR ≥300 mg/g or dipstick proteinuria 2+ or higher vs eGFR ≥90 mL/min per 1·73 m2 plus ACR <10 mg/g or dipstick proteinuria negative). Both eGFR and ACR significantly improved peripheral artery disease risk discrimination beyond traditional predictors, with a substantial improvement prediction of amputation with ACR (difference in c-statistic 0·058, 95% CI 0·045-0·070). Patterns were consistent across clinical subgroups.

INTERPRETATION

Even mild-to-moderate chronic kidney disease conferred increased risk of incident peripheral artery disease, with a strong association between albuminuria and amputation. Clinical attention should be paid to the development of peripheral artery disease symptoms and signs in people with any stage of chronic kidney disease.

FUNDING

American Heart Association, US National Kidney Foundation, and US National Institute of Diabetes and Digestive and Kidney Diseases.

Kidney disease and venous thromboembolism: Does being woman make the difference?

The risk of venous thromboembolism (VTE) is increased across the spectrum of chronic kidney disease (CKD), from mild to more advanced CKD, and typically characterizes nephrotic syndrome (NS). VTE risk in patients with kidney disease may be due to underlying hemostatic abnormalities, including activation of pro-thrombotic factors, inhibition of endogenous anticoagulation systems, enhanced platelet activation and aggregation, and decreased fibrinolytic activity. The mechanisms involved differ depending on the cause of the kidney impairment (i.e. presence of NS or CKD stage). Sex and gender differences, as well as, environmental factors or comorbidities may play a modulating role; however, specific sex and gender data on this topic are still rare. The aim of the present review is to discuss the VTE risk associated with impairment of kidney function, the potential mechanism accounting for it and the impact of sex differences in this clinical setting.

Associations of urinary, glomerular, and tubular markers with the development of diabetic kidney disease in type 2 diabetes patients

OBJECTIVES

To evaluate the associations of urinary markers (eg albumin), glomerular (eg transferrin [TRF], immunoglobulin G [IgG]), and tubular (eg α1-microglobulin [α1-MG], β2-microglobulin [β2-MG]) markers with the development of diabetic kidney disease (DKD) in type 2 diabetes patients, as assessed by estimated glomerular filtration rate (eGFR) and albuminuria.

MATERIAL AND METHODS

A total of 252 type 2 diabetes patients and 50 nondiabetic controls from Tianjin, China, were selected. Diabetic patients were divided into three groups according to eGFR levels, including groups A, B, and C with eGFR ≥90 (n=94), 60-89 (n=94), and 30-59 (n=64) mL/min/1.73 m² . Urine levels of glomerular and tubular markers were detected in first morning urine samples, and their associations with eGFR and albuminuria analyzed.

RESULTS

Urinary levels of IgG, TRF, and β2-MG were significantly elevated in diabetic patients with normal eGFR compared with nondiabetic control subjects. Urinary levels of all markers increased per eGFR stratum. All kidney damage markers were significantly associated with eGFR in univariate analysis (standard β between -0.35 and -0.28; all P<.001). After adjusting for known confounders, only the tubular markers α1-MG (standard β=-0.25; P=.013) and β2-MG (standard β=-0.18; P=.039) retained significant associations with eGFR. All kidney damage markers were significantly associated with albuminuria, independent of age, duration of diabetes, and eGFR (standard β between 0.45 and 0.86; all P<.001).

CONCLUSION

Only the tubular markers α₁ -MG and β₂ -MG were associated with eGFR independent of albuminuria, suggesting that they may play an important role in the development of DKD.

Generation and characterization of monoclonal antibody against Advanced Glycation End Products in chronic kidney disease

Advanced Glycation End Products (AGEs) are toxins that are involved in structural and functional alterations of several organs and tissues, resulting in various pathologies. Several types of AGEs have been described but carboxymethyllysine (CML) is the major antigenic AGE compound. In this study, three different immunogenic carrier proteins (KLH, keyhole limpet hemocyanin; BSA, bovine serum albumin; and HSA, human serum albumin) were modified by glycation. The glycated molecules were used to produce epitope-specific monoclonal antibodies able to recognize the CML domain and to detect uremic toxins in the serum of patients with chronic kidney disease (CKD). A competitive ELISA was standardized in order to quantify CML in the sera of CKD patients. An increase in uremic toxins can compromise the clinical condition of these patients, thus, the detection and quantification of these toxins should contribute to a better management and understanding of this disease.

•

We isolated a monoclonal antibody able to recognize carboxymethyl lysine (CML) which is the major antigenic AGE compound.

•

A sensitive immunoassay was developed to detect and quantify CML in biological samples.

•

A correlation between chronic kidney disease (CKD) grade and the CML concentration deduced from the immunoassay was observed.

Proteinuria Is an Independent Risk Factor for First Incident Stroke in Adults Under Treatment for Hypertension in China

Background

Conflicting evidence exists regarding whether reduced estimated glomerular filtration rate (eGFR) and proteinuria are independent risk factors for stroke and its subtypes in hypertensive patients. This study investigated the association of these renal measures with first incident stroke in adults under treatment for hypertension in China.

Methods and Results

The study included 19 599 adults aged 45 to 75 years who participated in the China Stroke Primary Prevention Trial. Baseline eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation. Proteinuria was assessed by qualitative dipstick urinalysis and in a subset by the quantitative albumin–creatinine ratio method. Cox regression analysis was used to examine the effects of eGFR and proteinuria on the risk of first incident stroke. During a median of 4.5 years of follow‐up, a total of 585 first strokes (472 ischemic strokes) were identified. Compared to participants without proteinuria, participants with proteinuria (trace or more by dipstick) had a 35% increased risk of first stroke: the adjusted hazard ratio (HR) (95% CI) was 1.35 (1.09–1.66, P=0.005). The results were robust in subgroup analyses. In a subset with data on proteinuria measured by quantitative albumin–creatinine ratio, a similar association was found. In both independent and combined analyses with proteinuria, eGFR was not significantly associated with stroke.

Conclusions

In adults under treatment for hypertension in China, baseline proteinuria measured by dipstick or quantitative albumin–creatinine ratio, but not reduced eGFR, was found to be an independent risk factor for first incident stroke and ischemic stroke.

Influence of chronic kidney disease on cardiac structure and function

Chronic kidney disease (CKD), the presence of kidney dysfunction and/or damage, is a worldwide public health issue. Although CKD is independently associated with various subtypes of cardiovascular diseases, a recent international collaborative meta-analysis demonstrates that CKD is particularly strongly associated with heart failure, suggesting its critical impact on cardiac structure and function. Although numerous studies have investigated the association of CKD and cardiac structure and function, these studies substantially vary regarding source populations and methodology (e.g., measures of CKD and/or parameters of cardiac structure and function), making it difficult to reach universal conclusions. Nevertheless, in this review, we comprehensively examine relevant studies, discuss potential mechanisms linking CKD to alteration of cardiac structure and function, and demonstrate clinical implications as well as potential future research directions. We exclusively focus on studies investigating both CKD measures, kidney function (i.e., glomerular filtration rate [GFR], creatinine clearance, or levels of filtration markers), and kidney damage represented by albuminuria, since current international clinical guidelines of CKD recommend staging CKD and assessing its clinical risk based on both GFR and albuminuria.

Tubular proteinuria is the dominant type of proteinuria in an elderly community population in China

PURPOSE

To explore the types of proteinuria in the elderly population in China.

METHODS

Seven hundred and fourteen elderly people (≥ 60 years old) from Tianjin, China, were selected for the study. The albumin-to-creatinine ratio and α1-microglobulin-to-creatinine ratio from morning urine samples were used as indicators of proteinuria. The prevalence of proteinuria was evaluated and the proportion of three different types of proteinuria (mixed, glomerular, and tubular) was assessed in the subjects by analyzing these indicators.

RESULTS

Of the 714 subjects, 29.13 % had elevated ACR and 46.36 % had elevated MCR. The proportion of subjects with either elevated ACR or MCR was 53.78 %. The correlation between MCR and ACR was moderate (r = 0.58, R (2) = 0.34, P < 0.001). Overall, tubular proteinuria was dominant (45.83 %), followed by mixed glomerular and tubular proteinuria (35.68 %), and significantly higher than glomerular proteinuria. A diet high in salt was the independent risk factor for tubular proteinuria; physical activity was the independent risk factor for glomerular proteinuria. The risk of glomerular proteinuria was lower in males than in females, but the risk of tubular proteinuria was higher in males.

CONCLUSIONS

The prevalence of tubular proteinuria was higher than that of glomerular proteinuria, and the risk factors are different, in the elderly in China; therefore, tubular damage markers should get more attention in the overall population.

Effect of PKC-β Signaling Pathway on Expression of MCP-1 and VCAM-1 in Different Cell Models in Response to Advanced Glycation End Products (AGEs)

Advanced glycation end products (AGEs) are compounds classified as uremic toxins in patients with chronic kidney disease that have several pro-inflammatory effects and are implicated in the development of cardiovascular diseases. To explore the mechanisms of AGEs–endothelium interactions through the receptor for AGEs (RAGE) in the PKC-β pathway, we evaluated the production of MCP-1 and VCAM-1 in human endothelial cells (HUVECs), monocytes, and a coculture of both. AGEs were prepared by albumin glycation and characterized by absorbance and electrophoresis. The effect of AGEs on cell viability was assessed with an MTT assay. The cells were also treated with AGEs with and without a PKC-β inhibitor. MCP-1 and VCAM-1 in the cell supernatants were estimated by ELISA, and RAGE was evaluated by immunocytochemistry. AGEs exposure did not affect cell viability, but AGEs induced RAGE, MCP-1, and VCAM-1 expression in HUVECs. When HUVECs or monocytes were incubated with AGEs and a PKC-β inhibitor, MCP-1 and VCAM-1 expression significantly decreased. However, in the coculture, exposure to AGEs and a PKC-β inhibitor produced no significant effect. This study demonstrates, in vitro, the regulatory mechanisms involved in MCP-1 production in three cellular models and VCAM-1 production in HUVECs, and thus mimics the endothelial dysfunction caused by AGEs in early atherosclerosis. Such mechanisms could serve as therapeutic targets to reduce the harmful effects of AGEs in patients with chronic kidney disease.

Management of diabetic nephropathy in older patients: a need for flexible guidelines

As the population ages and diabetes mellitus increases in prevalence, the incidence of diabetic nephropathy (DN) is becoming a disease of older people (aged ≥ 75 years). As the epidemiology of diabetes mellitus and DN shifts toward this patient population, the pathogenesis of DN in old age is changing: the pathologic findings suggest ischemia and hypertension, and the classic Kimmelstiel-Wilson lesions may be absent. The demographic shift in the epidemiology and the associated changes in pathology because of aging and atherosclerosis will have a significant impact on various aspects related to the disease in old age. This article reviews the authors' current understanding of DN and its implications on clinical management relevant to current guidelines.

Differential effects of indoxyl sulfate and inorganic phosphate in a murine cerebral endothelial cell line (bEnd.3)

Endothelial dysfunction plays a key role in stroke in chronic kidney disease patients. To explore the underlying mechanisms, we evaluated the effects of two uremic toxins on cerebral endothelium function. bEnd.3 cells were exposed to indoxyl sulfate (IS) and inorganic phosphate (Pi). Nitric oxide (NO), reactive oxygen species (ROS) and O2•⁻ were measured using specific fluorophores. Peroxynitrite and eNOS uncoupling were evaluated using ebselen, a peroxide scavenger, and tetrahydrobiopterin (BH₄), respectively. Cell viability decreased after IS or Pi treatment (p < 0.01). Both toxins reduced NO production (IS, p < 0.05; Pi, p < 0.001) and induced ROS production (p < 0.001). IS and 2 mM Pi reduced O2•⁻ production (p < 0.001). Antioxidant pretreatment reduced ROS levels in both IS- and Pi-treated cells, but a more marked reduction of O2•⁻ production was observed in Pi-treated cells (p < 0.001). Ebselen reduced the ROS production induced by the two toxins (p < 0.001); suggesting a role of peroxynitrite in this process. BH₄ addition significantly reduced O2•⁻ and increased NO production in Pi-treated cells (p < 0.001), suggesting eNOS uncoupling, but had no effect in IS-treated cells. This study shows, for the first time, that IS and Pi induce cerebral endothelial dysfunction by decreasing NO levels due to enhanced oxidative stress. However, Pi appears to be more deleterious, as it also induces eNOS uncoupling.

Association of renal biochemical parameters with left ventricular diastolic dysfunction in a community-based elderly population in China: a cross-sectional study

Background

Relationship of left ventricular diastolic dysfunction (LVDD) with parameters that could provide more information than hemodynamic renal indexes has not been clarified. We aimed to explore the association of comprehensive renal parameters with LVDD in a community-based elderly population.

Methods

1,166 community residents (aged ≥ 65 years, 694 females) participating in the Shanghai Heart Health Study with complete data of renal parameters were investigated. Echocardiography was used to evaluate diastolic function with conventional and tissue Doppler imaging techniques. Serum urea, creatinine, urea-to-creatinine ratio, estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were analyzed on their associations with LVDD.

Results

The prevalence of LVDD increased in proportion to increasing serum urea, urea-to-creatinine ratio and UACR. These three renal parameters were found negatively correlated to peak early (E) to late (A) diastolic velocities ratio (E/A), and positively to left atrial volume index; UACR also positively correlated with E to peak early (E’) diastolic mitral annular velocity ratio (E/E’). Serum urea, urea-to-creatinine ratio and UACR correlated with LVDD in logistic univariate regression analysis, and urea-to-creatinine ratio remained independently correlated to LVDD [Odds ratio (OR) 2.82, 95% confidence interval (CI) 1.34–5.95] after adjustment. Serum urea (OR 1.18, 95%CI 1.03–1.34), creatinine (OR 6.53, 95%CI 1.70­–25.02), eGFR (OR 0.22, 95%CI 0.07–0.65) and UACR (OR 2.15, 95%CI 1.42–3.24) were revealed independent correlates of advanced (moderate and severe) LVDD.

Conclusions

Biochemical parameters of renal function were closely linked with LVDD. This finding described new cardio-renal relationship in the elderly population.

Pathogenesis of chronic cardiorenal syndrome: is there a role for oxidative stress?

Cardiorenal syndrome is a frequently encountered clinical condition when the dysfunction of either the heart or kidneys amplifies the failure progression of the other organ. Complex biochemical, hormonal and hemodynamic mechanisms underlie the development of cardiorenal syndrome. Both in vitro and experimental studies have identified several dysregulated pathways in heart failure and in chronic kidney disease that lead to increased oxidative stress. A decrease in mitochondrial oxidative metabolism has been reported in cardiomyocytes during heart failure. This is balanced by a compensatory increase in glucose uptake and glycolysis with consequent decrease in myocardial ATP content. In the kidneys, both NADPH oxidase and mitochondrial metabolism are important sources of TGF-β1-induced cellular ROS. NOX-dependent oxidative activation of transcription factors such as NF-kB and c-jun leads to increased expression of renal target genes (phospholipaseA2, MCP-1 and CSF-1, COX-2), thus contributing to renal interstitial fibrosis and inflammation. In the present article, we postulate that, besides contributing to both cardiac and renal dysfunction, increased oxidative stress may also play a crucial role in cardiorenal syndrome development and progression. In particular, an imbalance between the renin-angiotensin-aldosterone system, the sympathetic nervous system, and inflammation may favour cardiorenal syndrome through an excessive oxidative stress production. This article also discusses novel therapeutic strategies for their potential use in the treatment of patients affected by cardiorenal syndrome.

Cardiorenal syndrome--current understanding and future perspectives

Combined cardiac and renal dysfunction has gained considerable attention. Hypotheses about its pathogenesis have been formulated, albeit based on a relatively small body of experimental studies, and a clinical classification system has been proposed. Cardiorenal syndrome, as presently defined, comprises a heterogeneous group of acute and chronic clinical conditions, in which the failure of one organ (heart or kidney) initiates or aggravates failure of the other. This conceptual framework, however, has two major drawbacks: the first is that, despite worldwide interest, universally accepted definitions of cardiorenal syndrome are lacking and characterization of heart and kidney failure is not uniform. This lack of consistency hampers experimental studies on mechanisms of the disease. The second is that, although progress has been made in developing hypotheses for the pathogenesis of cardiorenal syndrome, these initiatives are at an impasse. No hierarchy has been identified in the myriad of haemodynamic and non-haemodynamic factors mediating cardiorenal syndrome. This Review discusses current understanding of cardiorenal syndrome and provides a roadmap for further studies in this field. Ultimately, discussion of the definition and characterization issues and of the lack of organization among pathogenetic factors is hoped to contribute to further advancement of this complex field.

The cardiorenal syndrome in heart failure: cardiac? renal? syndrome?

There has been increasing interest on the so-called cardiorenal syndrome (CRS), defined as a complex pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other. In this review, we contend that there is lack of evidence warranting the adoption of a specific clinical construct such as the CRS within the heart failure (HF) syndrome by demonstrating that: (a) the approaches and tools regarding the definition of kidney involvement in HF are suboptimal; (b) development of renal failure in HF is often confounded by age, hypertension, and diabetes; (c) worsening of renal function (WRF) in HF may be largely independent of alterations in cardiac function; (d) the bidirectional association between HF and renal failure is not unique and represents one of the several such associations encountered in HF; and (e) inflammation is a common denominator for HF and associated noncardiac morbidities. Based on these arguments, we believe that dissecting one of the multiple bidirectional associations in HF and constructing the so-called cardiorenal syndrome is not justified pathophysiologically. Fully understanding of all morbid associations and not only the cardiorenal is of great significance for the clinician who is caring for the patient with HF.

Systemic arterial and venous determinants of renal hemodynamics in congestive heart failure

Heart and kidney interactions are fascinating, in the sense that failure of the one organ strongly affects the function of the other. In this review paper, we analyze how principal driving forces for glomerular filtration and renal blood flow are changed in heart failure. Moreover, renal autoregulation and modulation of neurohumoral factors, which can both have repercussions on renal function, are analyzed. Two paradigms seem to apply. One is that the renin-angiotensin system (RAS), the sympathetic nervous system (SNS), and extracellular volume control are the three main determinants of renal function in heart failure. The other is that the classical paradigm to analyze renal dysfunction that is widely applied in nephrology also applies to the pathophysiology of heart failure: pre-renal, intra-renal, and post-renal alterations together determine glomerular filtration. At variance with the classical paradigm is that the most important post-renal factor in heart failure seems renal venous hypertension that, by increasing renal tubular pressure, decreases GFR. When different pharmacological strategies to inhibit the RAS and SNS and to assist renal volume control are considered, there is a painful lack in knowledge about how widely applied drugs affect primary driving forces for ultrafiltration, renal autoregulation, and neurohumoral control. We call for more clinical physiological studies.

Glomerular and tubular damage markers in individuals with progressive albuminuria

BACKGROUND AND OBJECTIVES

Albuminuria is associated with risk for renal and cardiovascular disease. It is difficult to predict which persons will progress in albuminuria. This study investigated whether assessment of urinary markers associated with damage to different parts of the nephron may help identify individuals that will progress in albuminuria.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Individuals were selected from a prospective community-based cohort study with serial follow-up and defined as "progressors" if they belonged to the quintile of participants with the most rapid annual increase in albuminuria, and reached an albuminuria ≥150 mg/d during follow-up. Patients with known renal disease or macroalbuminuria at baseline were excluded. Each progressor was matched to two control participants, based on baseline albuminuria, age, and sex. Furthermore, damage markers were measured in a separate set of healthy individuals.

RESULTS

After a median follow-up of 8.6 years, 183 of 8394 participants met the criteria for progressive albuminuria. Baseline clinical characteristics were comparable between progressors and matched controls (n=366). Both had higher baseline albuminuria than the overall population. Urinary excretion of the glomerular damage marker IgG was significantly higher in progressors, whereas urinary excretion of proximal tubular damage markers and inflammatory markers was lower in these individuals compared with controls. Healthy individuals (n=109) had the lowest values for all urinary damage markers measured.

CONCLUSIONS

These data suggest that albuminuria associated with markers of glomerular damage is more likely to progress, whereas albuminuria associated with markers of tubulointerstitial damage is more likely to remain stable.

The chronic kidney disease “epidemy”

Chronic kidney disease is a general term for heterogenous disorders with >3 months duration affecting kidney structure and function. Nowadays, involving 10–16% of the adult population worldwide, chronic kidney disease is recognised as a major global public health problem. The number of cases is continuously increasing. In this review, epidemiology, definition, new classification and a conceptual model for development, progression and complications of chronic kidney disease as well as strategies to improve outcome are summarized. Orv. Hetil., 2013, 154, 43–51.

Hemostatic defects in liver and renal dysfunction

Multiple and complex abnormalities of hemostasis are revealed by laboratory tests in such common diseases as cirrhosis and end-stage renal insufficiency. Because these abnormalities are associated with a bleeding tendency, a causal relationship is plausible. Accordingly, an array of transfusional and nontransfusional medications that improve or correct these abnormalities is used to prevent or stop hemorrhage. However, recent data indicate that the use of hemostatic drugs is scarcely justified mechanistically or clinically. In patients with uremia, the bleeding tendency (mainly expressed by gastrointestinal bleeding and hematoma formation at kidney biopsy) is reduced dramatically by the improvement of anemia obtained with the regular use of erythropoietin. In cirrhosis, the most severe and frequent hemorrhagic symptom (acute bleeding from esophageal varices) is not explained by abnormalities in such coagulation screening tests as the prothrombin and partial thromboplastin times, because formation of thrombin the final coagulation enzyme is rebalanced by low naturally occurring anticoagulant factors in plasma that compensate for the concomitant decrease of procoagulants. Rebalance also occurs for hyperfibrinolysis and platelet abnormalities. These findings are consistent with clinical observations that transfusional and nontransfusional hemostatic medications are of little value as adjuvants to control bleeding in advanced liver disease. Particularly in uremia, but also in cirrhosis, thrombosis is becoming a cogent problem.

Associations of kidney disease measures with mortality and end-stage renal disease in individuals with and without hypertension: a meta-analysis

BACKGROUND

Hypertension is the most prevalent comorbidity in individuals with chronic kidney disease. However, whether the association of the kidney disease measures, estimated glomerular filtration rate (eGFR) and albuminuria, with mortality or end-stage renal disease (ESRD) differs by hypertensive status is unknown.

METHODS

We did a meta-analysis of studies selected according to Chronic Kidney Disease Prognosis Consortium criteria. Data transfer and analyses were done between March, 2011, and June, 2012. We used Cox proportional hazards models to estimate the hazard ratios (HR) of mortality and ESRD associated with eGFR and albuminuria in individuals with and without hypertension.

FINDINGS

We analysed data for 45 cohorts (25 general population, seven high-risk, and 13 chronic kidney disease) with 1,127,656 participants, 364,344 of whom had hypertension. Low eGFR and high albuminuria were associated with mortality irrespective of hypertensive status in the general population and high-risk cohorts. All-cause mortality risk was 1·1-1·2 times higher in individuals with hypertension than in those without hypertension at preserved eGFR. A steeper relative risk gradient in individuals without hypertension than in those with hypertension at eGFR range 45-75 mL/min per 1·73 m(2) led to much the same mortality risk at lower eGFR. With a reference eGFR of 95 mL/min per 1·73 m(2) in each group to explicitly assess interaction, adjusted HR for all-cause mortality at eGFR 45 mL/min per 1·73 m(2) was 1·77 (95% CI 1·57-1·99) in individuals without hypertension versus 1·24 (1·11-1·39) in those with hypertension (p for overall interaction=0·0003). Similarly, for albumin-creatinine ratio of 300 mg/g (vs 5 mg/g), HR was 2·30 (1·98-2·68) in individuals without hypertension versus 2·08 (1·84-2·35) in those with hypertension (p for overall interaction=0·019). We recorded much the same results for cardiovascular mortality. The associations of eGFR and albuminuria with ESRD, however, did not differ by hypertensive status. Results for chronic kidney disease cohorts were similar to those for general and high-risk population cohorts.

INTERPRETATION

Chronic kidney disease should be regarded as at least an equally relevant risk factor for mortality and ESRD in individuals without hypertension as it is in those with hypertension.

FUNDING

US National Kidney Foundation.

Cardiac structure and function and renal insufficiency in the oldest old

BACKGROUND

People over the age of 85 years have a high incidence of cardiovascular disease and chronic kidney disease.

HYPOTHESIS

There is an association between renal function and cardiac structure and function in subjects 85 years of age.

METHODS

Subjects born in the years 1920 and 1921 were recruited from the Jerusalem Longitudinal Cohort Study. Echocardiography was performed at the subject's home with assessment of cardiac structure and function. Glomerular filtration rate (GFR) was assessed by the Cockroft-Gault formula, with abnormal GFR defined as ≤60 mL/min/1.73 m(2).

RESULTS

There were 310 subjects who were enrolled. When GFR was examined as a continuous variable, linear regression showed a small although statistically significant relationship between GFR and left atrial volume (r = 0.15, P < 0.014), left ventricular mass index (r = 0.12, P < 0.04), and ejection fraction (r = 0.19, P < 0.03) but not with indices of diastolic function (r = 0.02, P < 0.72). However, using the accepted clinical cutoff of 60 mL/min/1.73 m(2), there were no significant differences between subjects with normal and abnormal GFR in indices of cardiac structure. Ejection fraction (57.0 ± 10.4% vs 54.4 ± 10.3%; P = 0.08) and indices of diastolic function (E/e' 12.4 ± 5.0 vs 12.3 ± 4.6; P = 0.89) were not significantly different between the 2 groups.

CONCLUSIONS

A weak and clinically insignificant association was found between GFR as a continuous variable and indices of cardiac function. However, using the clinically accepted cutoff, no association between abnormal GFR and cardiac structure or function was observed.

Identification of risk factors for chronic Q fever, the Netherlands

Since 2007, the Netherlands has experienced a large Q fever outbreak. To identify and quantify risk factors for development of chronic Q fever after Coxiella burnetii infection, we performed a case-control study. Comorbidity, cardiovascular risk factors, medications, and demographic characteristics from 105 patients with proven (n = 44), probable (n = 28), or possible (n = 33) chronic Q fever were compared with 201 patients who had acute Q fever in 2009 but in whom chronic Q fever did not develop (controls). Independent risk factors for development of proven chronic Q fever were valvular surgery, vascular prosthesis, aneurysm, renal insufficiency, and older age.

Chronic kidney disease

Chronic kidney disease is a general term for heterogeneous disorders affecting kidney structure and function. The 2002 guidelines for definition and classification of this disease represented an important shift towards its recognition as a worldwide public health problem that should be managed in its early stages by general internists. Disease and management are classified according to stages of disease severity, which are assessed from glomerular filtration rate (GFR) and albuminuria, and clinical diagnosis (cause and pathology). Chronic kidney disease can be detected with routine laboratory tests, and some treatments can prevent development and slow disease progression, reduce complications of decreased GFR and risk of cardiovascular disease, and improve survival and quality of life. In this Seminar we discuss disease burden, recommendations for assessment and management, and future challenges. We emphasise clinical practice guidelines, clinical trials, and areas of uncertainty.