Is the dialysate calcium concentration of 1.75 mmol/L suitable for Chinese patients on maintenance hemodialysis?

We studied the effects of increasing the dialysate calcium concentration (DCa) to 1.75 mmol/L on controlling chronic kidney disease-mineral and bone disorder in Chinese patients on maintenance hemodialysis (MHD). We reviewed the data of MHD patients in one center (cohort 1) during prior 10 years and analyzed the risk factors of mortality and transference calcification (TC) in120 MHD patients surviving in 2003 (cohort 2). A multicenter, prospective, parallel-group, controlled trial (cohort 3) was also conducted from January 2011 to December 2012. The DCa at one center was increased from 1.5 to 1.75 mmol/L but was not changed at the other two centers. The clinical outcomes, biochemical parameters, medicine treatments, and TC markers [aortic arch calcification score (AoACS)] were compared between groups. In cohort 1, the annual mean serum iPTH increased significantly over 10 years. In cohort 1, 72 patients survived for 10 years, whose doses of calcium salts and active vitamin D3 and AoACs increased progressively. In cohort 2, the main cause of death was cardiocerebrovascular disease (CCVD) (n = 18, 48.6 %). Male sex and lower serum calcium concentrations were independent risk factors for CCVD mortality. In cohort 3, serum phosphorus, iPTH, and 25(OH)D decreased and serum calcium increased significantly; also, the doses of calcium and vitamin D3 decreased from 2011 to 2012 in the DCa 1.75 group. There were no significant differences in clinical outcomes either between groups or between the two calendar years. Our results indicate that increasing DCa to 1.75 mmol/L can decrease the elevated levels of serum iPTH and phosphorus, reduce the doses of calcium and vitamin D3, and be safe for short periods of time.

Low serum potassium level is associated with nonalcoholic fatty liver disease and its related metabolic disorders

CONTEXT

Subjects with nonalcoholic fatty liver disease (NAFLD) have a high risk of developing type 2 diabetes and cardiovascular diseases. Low serum potassium concentration or low dietary potassium intake can result in metabolic disorders.

OBJECTIVE

Our objective was to evaluate the association between low serum potassium level and prevalence of NAFLD in a Chinese population.

DESIGN

A population-based cross-sectional study.

PATIENTS

We conducted a community-based study in 8592 subjects to investigate the association of serum potassium with the risk of prevalent NAFLD. NAFLD was diagnosed by hepatic ultrasonography.

RESULTS

The prevalence rate of NAFLD was 30·3% in this population and gradually decreased across serum potassium quartiles. With the reduction in serum potassium level, participants have larger waist circumference (WC) and more severe insulin resistance. The correlations hold also in multivariate linear regression analysis. In logistic regression analysis, compared with subjects in the highest quartile of serum potassium level, the adjusted odds ratios (ORs) in the lowest quartile was 1·33 [95% confidence interval (CI), 1·11-1·60] for NAFLD, 1·81 (95% CI, 1·49-2·19) for insulin resistance and 1·58 (95% CI, 1·30-1·93) for central obesity. In subgroup analysis after multiple adjustments, significant relation between serum potassium level and prevalent NAFLD was detected in women, younger subjects, those with insulin resistance and those with central obesity, respectively.

CONCLUSION

Low serum potassium level significantly associated with prevalence of NAFLD in middle-aged and elderly Chinese.

Additive effect of aldose reductase Z-4 microsatellite polymorphism and glycaemic control on cataract development in type 2 diabetes

AIMS

To examine the additive effect of the z-4 microsatellite polymorphism of aldose reductase gene (ALR2) and glycaemic control on risk of cataract in a prospective cohort of Chinese type 2 diabetic patients.

METHODS

The (CA)n microsatellite polymorphism of ALR2 was determined using PCR followed by capillary gel electrophoresis. Cataract was defined by presence of lens opacity on direct ophthalmoscopy or history of cataract surgery. A non-linear curve approach was used to identify the threshold of glycated hemoglobin (HbA1c) at which the odds ratio (OR) for cataract started to increase. The association of z-4 allele with cataract, above and below this threshold, was assessed using multiple logistic regression analysis.

RESULTS

Of the 5823 patients analyzed, 28.1% had cataracts. After adjusting for conventional risk factors and using non-z-4 carriers with HbA1c<8.0% as referent group (n = 3173), the OR (95% confidence intervals) for cataract was highest in z-4 carriers with HbA1c ≥ 8.0% [1.43 (1.05-1.96), n = 244], compared to non-z-4 carriers with HbA1c ≥ 8.0 [1.27 (1.10-1.47), n = 1836] and z-4 carriers with HbA1c<8.0%[1.01 (0.77-1.29), n = 420, P(trend) < 0.001]. This additive association remained significant after additional adjustments for drug use (P(trend) = 0.002) and renal function (P(trend) = 0.01).

CONCLUSIONS

In type 2 diabetic patients with suboptimal glycaemic control, the z-4 allele of ALR2 (CA)n polymorphism was independently associated with increased susceptibility to cataracts.

Outcome of live and deceased donor renal transplantation in patients aged ≥55 years: A single-center experience

Renal transplantation (RTx) has now become an accepted therapeutic modality of choice for elderly ESRD patients. This single-center study was undertaken to evaluate the outcome of RTx in ESRD patients ≥55 years. A total of 103 patients underwent RTx 79 living related living donors [LD], 24 deceased donors [DD]) at our center. Post-transplant immunosuppression consisted of calcineurin inhibitor-based regimen. The mean donor age was 58.3 years in the LD group and 59.5 years in the DD group. Male recipients constituted 92% in LD and 75% in DD group. In living donor renal transplantation, 1- and 5-year patient survival was 93% and 83.3% respectively and death-censored graft survival was 97.3% and 92.5% respectively. There were 12.6% biopsy proven acute rejection (BPAR) episodes and 12.6% patients were lost, mainly due to infections. In deceased donor renal transplantation, 1- and 5-year patient survival was 79.1% and 74.5% respectively and death-censored graft survival was 95.8% and 85.1% respectively. There were 12.5% BPAR episodes and 25% of patients were lost, mainly due to infections. RTx in ESRD (≥55 years) patients has acceptable patient and graft survival if found to have cardiac fitness and therefore should be encouraged.

Increasing cGMP-dependent protein kinase activity attenuates unilateral ureteral obstruction-induced renal fibrosis

Our previous studies support the protective effect of cGMP and cGMP-dependent protein kinase I (PKG-I) pathway on the development of renal fibrosis. Therefore, in the present studies, we determined whether pharmacologically or genetically increased PKG activity attenuates renal fibrosis in a unilateral ureteral obstruction (UUO) model and also examined the mechanisms involved. To increase PKG activity, we used the phosphodiesterase 5 inhibitor sildenafil and PKG transgenic mice. UUO model was induced in wild-type or PKG-I transgenic mice by ligating the left lateral ureteral and the renal fibrosis was observed after 14 days of ligation. Sildenafil was administered into wild-type UUO mice for 14 days. In vitro, macrophage and proximal tubular cell function was also analyzed. We found that sildenafil treatment or PKG transgenic mice had significantly reduced UUO-induced renal fibrosis, which was associated with reduced TGF-β signaling and reduced macrophage infiltration into kidney interstitial. In vitro data further demonstrated that both macrophages and proximal tubular cells were important sources of UUO-induced renal TGF-β levels. The interaction between macrophages and tubular cells contributes to TGF-β-induced renal fibrosis. Taken together, these data suggest that increasing PKG activity ameliorates renal fibrosis in part through regulation of macrophage and tubular cell function, leading to reduced TGF-β-induced fibrosis.

Prevention of contrast-induced nephropathy with prostaglandin E1 in high-risk patients undergoing percutaneous coronary intervention

PURPOSE

Contrast-induced nephropathy (CIN) is an important complication in the use of iodinated contrast media. The present study aimed to assess the safety and efficacy of prostaglandin E1 (PGE1) in prevention of CIN in patients with high-risk factors undergoing percutaneous coronary intervention (PCI).

METHODS

The study group consisted of 163 patients who had undergone a coronary intervention procedure between January 1, 2012 and October 31, 2012. Study participants were randomly assigned to either the PGE1 group (82 patients) or the control group (81 patients). Patients in the PGE1 group received PGE1 intravenous infusion of 20 ng/kg/min for 6 h before and after the administration of contrast media. The control group received 0.9 % sodium chloride solution for routine hydration only. A nonionic, low-osmolality contrast agent was used in our laboratory at this time. Serum creatinine (Scr) values and estimated glomerular filtration rate were measured before and within 48 h of the administration of contrast agents. CIN was defined as an increase of ≥0.5 mg/dL or ≥ a 25 % increase in Scr concentrations over baseline within 48 h of angiography.

RESULTS

The amount of contrast agent administered was similar for the PGE1 and control groups (156 ± 63 vs. 161 ± 68 mL, P > 0.05). The incidence of CIN was lower in the PGE1 group than in the control group (3.7 vs. 11.1 %, P < 0.05). No serious adverse effects were observed.

CONCLUSIONS

In patients with high-risk factors undergoing PCI, the use of PGE1 for prevention of CIN is safe and efficacious.

Prevalence of chronic kidney disease and its association with metabolic diseases: a cross-sectional survey in Zhejiang province, Eastern China

Background

The prevalence of chronic kidney disease (CKD) and metabolic diseases has increased at different rates in different regions in China. The aim of our study was to estimate the prevalence of CKD and to analyze associated risk factors of CKD in Zhejiang province, Eastern China.

Methods

A cross-sectional survey of 11,013 adults was conducted from September 2009 to June 2012 in Zhejiang Province, located in Eastern China. CKD was defined as having an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² or the presence of albuminuria. Medical history, physical examination and laboratory data were used to diagnose metabolic diseases. Age- and sex-standardized prevalence was calculated using the data on the population distribution in China in 2010. We examined risk factors associated with decreased renal function and albuminuria using multivariate logistic regression.

Results

A total of 10,384 adults (94.3%) completed the screening. The standardized prevalence of reduced renal function (eGFR < 60 mL/min/1.73 m²) was 1.83% (95% CI 1.52–2.13) and that of albuminuria was 8.65% (95% CI 7.98–9.31). The overall prevalence of CKD was 9.88% (95% CI 9.18–10.59). The prevalence of reduced renal function was greater in the eastern rural areas in Zhejiang province. Multivariate logistic regression revealed that metabolic diseases such as diabetes, obesity, hypertension, and hyperuricemia were independent risk factors of CKD. Patients with metabolic diseases had a significantly (P < 0.001) higher prevalence of CKD than those without such diseases.

Conclusions

CKD has become a severe public health problem in Zhejiang Province, and metabolic diseases may increase the risk of CKD in Zhejiang population.

Non-aristolochic acid prescribed Chinese herbal medicines and the risk of mortality in patients with chronic kidney disease: results from a population-based follow-up study

OBJECTIVES

To evaluate the relationship between the use of non-aristolochic acid (AA) prescribed Chinese herbal medicines (CHMs) and the risk of mortality in patients with chronic kidney disease (CKD).

DESIGN

Nationwide population-based follow-up study.

SETTING

Longitudinal health insurance database sampled from the Taiwan National Health Insurance Research Database.

PARTICIPANTS

A total of 47 876 patients with CKD were identified. Participants who had ever used AA-containing CHMs, had cancer or HIV prior to the diagnosis of CKD, died within the first month of CKD diagnosis and who were not Taiwanese citizens were excluded. A total of 13 864 participants were eligible for final analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause mortality among patients with CKD between 2000 and 2008.

RESULTS

After controlling for potential confounders, we found that participants who started to receive non-AA prescribed CHMs after the diagnosis of CKD had a lower risk of mortality as compared with non-users of non-AA prescribed CHMs (adjusted HR (aHR) 0.6; 95% CI 0.4 to 0.7, p<0.001). Moreover, participants who had used non-AA prescribed CHMs prior to and after the diagnosis of CKD also had a lower risk of mortality than non-users (aHR 0.6; 95% CI 0.5 to 0.8, p<0.001). In subgroup analyses, we found that such an inverse association was present only among patients who were not eligible to receive erythropoietin therapy (ie, serum creatinine ≦6 mg/dL and/or haematocrit value ≧28%).

CONCLUSIONS

Patients who received non-AA prescribed CHMs after the diagnosis of CKD, yet before the start of erythropoietin therapy had a lower risk of mortality than those who did not.

Pediatric chronic kidney disease rates in Southern Israel are higher than reported

Background: The incidence and prevalence of pediatric chronic kidney disease (p-CKD) in developed countries has previously been estimated to be 12 and 75 cases/10 ⁶ population respectively, much lower than reports in young adults (age 20-40) (40,000/10 ⁶). Thus, the extent of p-CKD may be underestimated.

Methods: Being the only Pediatric Nephrology center in Southern Israel, we reviewed all detected cases of p-CKD (stages 1-5) between 1994-2008. We then prospectively summarized the incidence and prevalence of CKD between 2009-2010. 

Results: We retrospectively identified 192 children (53.9% of Bedouin origin, 53.4% males, median diagnosis age: 1 year) with CKD. The prevalence in December 2008 was 795 cases/10 ⁶ for all CKD stages and 331/10 ⁶ for CKD stage >2. Calculated incidence for the study period (1994-2008) was 46/10 ⁶/year. The main CKD etiologies were: hypodysplasia: 35%; obstructive uropathy: 13%; genetic renal diseases: 28% and glomerulonephritis: 15%. The proportions of children in each CKD stage were as follows: stage 1: 50%; stages 2-4: 30%; stage 5: 20%. During a subsequent two-year study period we identified 26 new CKD cases (incidence: 54 cases/10 ⁶/year). 

Conclusions: p-CKD rates in our area are higher than reported and maybe even higher if asymptomatic populations are screened. Fifty percent of detected cases have CKD stage 1. This may contribute significantly to CKD beyond the pediatric age.

Evolution of chronic kidney disease in patients with systemic lupus erythematosus over a long-period follow-up: a single-center inception cohort study

The objective is to investigate the accrual rate and risk factors of chronic kidney disease (CKD) in an inception cohort of patients with systemic lupus erythematosus (SLE) followed at a single tertiary center. A prospectively collected database of 256 consecutive patients with SLE followed over a 25-year period was systematically interrogated for demographic, disease manifestations, co-morbidities, and outcome. Standardized SLE activity and damage scores were determined for the first and last study visits, and estimated glomerular filtration rate (eGFR; MDRD formula) was calculated at the time of diagnosis and at each year of the follow-up. CKD was defined as eGFR <60 ml/min/1.73 m(2). Results were analyzed with univariate and multivariate models and Kaplan-Meier curves, as appropriate. The cohort was predominantly female (90 %) and Jewish (91.1 %). Mean age at diagnosis was 38 ± 15.5 years, mean SLE activity score 6.4 ± 3.8, mean disease duration 8.8 ± 6.6 years, and mean damage score 0.2 ± 0.6. Seventy-five patients (30.8 %) were diagnosed with American College of Rheumatology (ACR)-defined lupus renal disease during the study period. There was a progressive decrease in eGFR over time. The prevalence of CKD was 46.7 % in patients with ACR-defined renal lupus disease and 16.4 % in those without. The hazards ratio for CKD was significantly higher in patients with lupus nephritis (LN) than without (p < 0.001). Earlier CKD was positively associated with hypertension (p = 0.01), older age at diagnosis (p = 0.01), and LN (p < 0.001), and negatively associated with hydroxychloroquine treatment (p < 0.001). The prevalence of CKD increases cumulatively in patients with SLE, also in those without overt lupus renal disease. Lupus renal disease poses a significant hazard for earlier development of CKD, and hypertension is a major risk factor for patients with and without nephritis. Antimalarial treatment is associated with renal preservation only in patients with lupus nephritis.

Knowledge, attitudes, and practices towards prevention and early detection of chronic kidney disease

OBJECTIVE

To describe the knowledge, attitudes and practices of Jordanian patients with chronic illnesses towards prevention and early detection of chronic kidney disease.

BACKGROUND

Patients with chronic illnesses such as hypertension and diabetes need to adopt healthy attitudes and practices and gain knowledge regarding prevention and early detection of kidney disease to decrease the prevalence of dialysis-related complications and costs.

METHODS

A total of 740 patients were recruited from out-patients clinics in Jordan. Knowledge, attitudes and practices about kidney disease prevention and early detection were measured using the Chronic Kidney Disease Screening Index which was developed by the researcher and tested for validity and reliability.

RESULTS

The results revealed that most of the participants have knowledge about kidney disease; however, half of them had wrong information related to signs and symptoms of chronic kidney disease. The majority of the participants were not aware about the importance of discovering health problems at early stages.

CONCLUSION AND IMPLICATIONS

Improvement in population understanding about chronic kidney disease is needed to advance their awareness and practices to make appropriate decisions towards health promotion and better quality of life.

IMPLICATION FOR POLICY DEVELOPMENT

Nurses need to be involved in development of protocols for screening and intervention programmes, taking into consideration the cultural issues and the financial status of individuals at risk for kidney disease. Governments should adopt a public health policy for chronic kidney disease that supports programmes for screening and programmes for improving public awareness for kidney disease prevention.

The serum levels of connective tissue growth factor in patients with systemic lupus erythematosus and lupus nephritis

OBJECTIVE

The expression of connective tissue growth factor mRNA in human kidneys may serve as an early marker for lupus nephritis progression. Therefore, we speculated that connective tissue growth factor may be involved in the pathogenesis of systemic lupus erythematosus and lupus nephritis. In this study, we set out to investigate the associations between serum connective tissue growth factor levels and clinicopathological features of patients with systemic lupus erythematosus and lupus nephritis.

METHODS

Serum samples from patients with non-renal systemic lupus erythematosus, renal biopsy-proven lupus nephritis and healthy control subjects were detected by enzyme-linked immunosorbent assay for serum connective tissue growth factor levels. The associations between connective tissue growth factor levels and clinicopathological features of the patients were further analysed.

RESULTS

The levels of serum connective tissue growth factor in patients with non-renal systemic lupus erythematosus and lupus nephritis were both significantly higher than those in the normal control group (34.14 ± 12.17 ng/ml vs. 22.8 ± 3.0 ng/ml, p<0.001; 44.1 ± 46.8 ng/ml vs. 22.8 ± 3.0 ng/ml, p = 0.035, respectively). There was no significant difference of the serum connective tissue growth factor levels between non-renal systemic lupus erythematosus and lupus nephritis group (34.14 ± 12.17 ng/ml vs. 44.1 ± 46.8 ng/ml, p = 0.183). Serum connective tissue growth factor levels were significantly higher in lupus nephritis patients with the following clinical manifestations, including anaemia (51.3 ± 51.4 ng/ml vs. 23.4 ± 9.7 ng/ml, p<0.001) and acute renal failure (85.5 ± 75.0 ng/ml vs. 31.2 ± 21.8 ng/ml, p = 0.002). Serum connective tissue growth factor levels in class IV were significantly higher than that in class II, III and V (57.6 ± 57.5 ng/ml vs. 18.7 ± 6.4 ng/ml, p = 0.019; 57.6 ± 57.5 ng/ml vs. 25.2 ± 14.9 ng/ml, p = 0.006; 57.6 ± 57.5 ng/ml vs. 30.5 ± 21.3 ng/ml, p = 0.017, respectively). Serum connective tissue growth factor levels were significantly higher in those with both active/chronic lesions than those in those with active lesions only in either class IV (84.9 ± 69.6 ng/ml vs. 40.0 ± 40.2 ng/ml, p = 0.001) or in combination of class III and IV lupus nephritis (63.3 ± 63.4 ng/ml vs. 38.3 ± 37.9 ng/ml, p = 0.035, respectively). Serum connective tissue growth factor levels were negatively associated with estimated glomerular filtration rate (r = -0.46, p<0.001) and positively associated with interstitial inflammation (r = 0.309, p = 0.002) and interstitial fibrosis (r = 0.287, p = 0.004). Serum connective tissue growth factor level was a risk factor for doubling of serum creatinine in lupus nephritis (p<0.001, hazard ratio = 1.015, 95% confidence intervals 1.008-1.022) in univariate analysis.

CONCLUSIONS

Serum connective tissue growth factor levels were significantly higher in lupus and correlated with chronic renal interstitial injury and doubling of serum creatinine in patients with lupus nephritis.

Effect of statins on cardiovascular events in patients with mild to moderate chronic kidney disease: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Statins are commonly used to lower total cholesterol levels in the general population to prevent cardiovascular events. However, the effects of statins in patients with chronic kidney disease remain unclear. We therefore performed a meta-analysis to assess the effects of statin therapy on cardiovascular outcomes in patients with mild to moderate chronic kidney disease.

METHODS

We systematically searched PubMed, EmBase, the Cochrane Central Register of Controlled Trials, proceedings of major meetings, and reference lists of articles for relevant literature. Only randomized clinical trials were included. Outcomes analysed included cardiovascular disease, total mortality, myocardial infarction, stroke, cardiovascular death, and possible drug-related adverse events. Subgroup analyses were also performed based on the population characteristics and clinical indexes.

RESULTS

Twelve trials met our inclusion criteria. Overall, statin therapy resulted in a 24% reduction in the risk of cardiovascular disease (RR = 0.76,95% confidence interval [CI], 0.72- 0.80), a 21% reduction in the risk of total mortality (RR = 0.79,95% CI, 0.72-0.86), a 34% reduction in the risk of myocardial infarction (RR = 0.66,95% CI, 0.52-0.83), a 30% reduction in the risk of stroke (RR = 0.70,95% CI, 0.57-0.85), and a 17% reduction in the risk of cardiovascular mortality (RR = 0.83,95% CI, 0.73- 0.93). No statistically significant drug-related adverse events were noted. Subgroup analysis indicated that some important factors such as baseline creatinine level ≥1.5 mg/dL, baseline glomerular filtration rate (GFR), and cardiovascular disease history could affect cardiovascular outcomes.

CONCLUSION

Statin therapy had a clear effect on cardiovascular disease, total mortality, stroke, and myocardial infarction in patients with mild to moderate renal disease. Subgroup analysis indicated that baseline GFR, baseline creatinine level, and a history of cardiovascular disease might play an important role in the cardiovascular outcomes.

Different types of atrial fibrillation, renal function, and mortality in elderly Chinese patients with coronary artery disease

Background

Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and the combined prevalence of these two disorders increases as the population ages. Both AF and CKD have risk factors for development of each other and eventual mortality. However, the relationship between different types of AF, CKD, and mortality remains unclear, especially in elderly Chinese patients with coronary artery disease.

Methods

This study comprised 1,050 patients of median age 86 (60–104) years with coronary artery disease. The end point was all-cause death during a mean follow-up of 417 days.

Results

Of 219 patients identified to have AF, 128 had paroxysmal type, 44 had persistent type, and 47 had permanent type. After adjusting for confounders, the estimated glomerular filtration rate was lower and the prevalence of CKD was higher in patients with permanent AF but not in those with paroxysmal or persistent AF. During follow-up, 106 non-CKD patients and 112 CKD patients died; mortality was significantly higher in CKD patients with AF than in those without AF (36 [40.9%] versus 76 [26.8%]), but not in patients without CKD (17 [13.0%] versus 89 [16.3%]). In patients with CKD, paroxysmal AF was independently associated with higher mortality after adjustment but not persistent or permanent AF. No type of AF had an independent association with mortality in patients without CKD.

Conclusion

All types of AF had a high prevalence. Permanent AF was independently associated with an increased prevalence of CKD and a decreased estimated glomerular filtration rate. Paroxysmal AF was an independent risk factor for survival in patients with CKD but not in those without CKD.

Body mass index and preclinical kidney disease in Indian adults aged 40 years and above without chronic kidney disease

BACKGROUND

Obesity is associated with diabetes and hypertension, two major risk factors for chronic kidney disease (CKD). Recently, it has been shown that obesity is associated with preclinical kidney disease defined by elevated levels of cystatin C among those without CKD in US adults. However, the association of obesity with cystatin C is not known in industrialized Asian populations.

METHODS

We examined 2,052 Indian adults aged 40-80 years in Singapore who were free of CKD defined as a serum creatinine-based estimated glomerular filtration rate (eGFRcr) <60 mL/min/1.73 m(2) and/or the presence of microalbuminuria. Body mass index (BMI) values were categorized into normal (18.5-24.9), overweight (25-29.9) and obese (≥30 kg/m(2)). Elevated serum cystatin C was defined as cystatin C ≥1 mg/L.

RESULTS

Overweight and obesity were significantly associated with elevated levels of cystatin C after adjusting for potential confounders including diabetes and hypertension and eGFRcr. Compared to those with normal weight, the odds ratio (95 % confidence interval) of elevated cystatin C was 1.49 (1.17-1.88) for overweight and 3.20 (2.33-4.39) for obese. This association was consistently present when BMI was analyzed as a continuous variable and also in subgroups of men, women and in those without diabetes mellitus or hypertension.

CONCLUSIONS

Higher BMI levels are associated with preclinical kidney disease in Indian adults aged 40 years and above without CKD.

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.

Derivation and validation of a risk score for contrast-induced nephropathy after cardiac catheterization in Chinese patients

BACKGROUND

To derive and validate a risk score for prediction of contrast-induced nephropathy (CIN) in the Chinese patients undergoing cardiac catheterization.

METHODS

The hospital medical records of 3945 patients undergoing coronary angiography or percutaneous coronary intervention were reviewed. Patients were randomly assigned into two cohorts: one was for derivation of risk score (n = 2764) and another for validation (n = 1181). The CIN was defined as an increase of serum creatinine level ≥44.2 μmol/L or ≥25 % and beyond its upper limit of normal value within 72 h following the procedure. On the basis of the odds ratio obtained from multivariate logistic regression, risk score of CIN was built up. The discrimination of the risk score was assessed using the area under the receiver operating characteristic curve and the calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

The incidences of CIN in the derivation and validation cohorts were 4.6 and 4.2 %, respectively. Independent predictors included age >60 years, hypertension, acute myocardial infarction, heart failure, use of intra-aortic balloon pump, decreased glomerular filtration rate and contrast volume >100 mL. The incidence of CIN was increased with increment of risk score. Both the derivation and validation cohorts showed adequate discrimination (an area under the ROC curve, 0.76 and 0.71, respectively) and good calibration (Hosmer-Lemeshow statistic test, P = 0.50 and P = 0.54, respectively).

CONCLUSION

A simple risk score for prediction of CIN development after cardiac catheterization in Chinese patients was built up by this study. Use of this risk score may help clinicians to perform early preventative strategies to minimize the risk of CIN.

The role of a low glomerular density and being overweight in the etiology of proteinuria in CKD patients without known glomerular diseases

BACKGROUND

Among the proteinuric patients with chronic kidney disease (CKD) who undergo a renal biopsy, we sometimes encounter those who cannot be classified as having a known primary or secondary glomerular disease. The pathogenesis and pathophysiology of these CKD patients have not been sufficiently elucidated.

METHODS

We recruited 34 proteinuric patients without known glomerular diseases. The glomerular volumes (GV) of the biopsy specimens from those patients were determined by a morphometric analysis. Glomerular hypertrophy (GH) was defined as having more than 3.6 × 10(6) μm(3). The patients were divided in two groups: those with GH (Group 1) and those without GH (Group 2). We compared the clinical and pathological parameters between Group 1 and Group 2, and among the three groups of patients: non-obese, overweight and obese group.

RESULTS

The patients with Group 1 had significantly higher values for the proportion of males, the body mass index (BMI), uric acid and significantly lower values for the glomerular density (GD). Of note, a multivariate regression analysis revealed that sex, the BMI and GD were significant factors correlated with the mean GV. The values for the mean GV were significantly higher in the overweight and obese groups as compared to the non-obese group, and the values for the GD were significantly lower in the obese group than in the non-obese group.

CONCLUSIONS

We identified a subgroup of patients who were characterized as having a high BMI and GV, and a low GD among the proteinuric CKD patients without known glomerular diseases.

Prevalence of CKD and its relationship to eGFR-related genetic loci and clinical risk factors in the SardiNIA study cohort

The prevalence of CKD and of renal failure vary worldwide, yet parallel increases in leading risk factors explain only part of the differential prevalence. We measured CKD prevalence and eGFR, and their relationship with traditional and additional risk factors, in a Sardinian founder population cohort. The eGFR was calculated using equations from the CKD Epidemiology Collaboration and Modification of Diet in Renal Disease studies. With use of the Kidney Disease Improving Global Outcomes guidelines, a cross-sectional analysis of 4842 individuals showed that CKD prevalence was 15.1%, including 3.6% of patients in the high-risk and 0.46% in the very-high-risk categories. Longitudinal analyses performed on 4074 of these individuals who completed three visits with an average follow-up of 7 years revealed that, consistent with other populations, average eGFR slope was -0.79 ml/min per 1.73 m(2) per year, but 11.4% of the participants had an eGFR decline >2.3 ml/min per 1.73 m(2) per year (fast decline). A genetic score was generated from 13 reported eGFR- and CKD-related loci, and univariable and multivariable analyses were applied to assess the relationship between clinical, ultrasonographic, and genetic variables with three outcomes: CKD, change in eGFR, and fast eGFR decline. Genetic risk score, older age, and female sex independently correlated with each outcome. Diabetes was associated with CKD prevalence, whereas hypertension and hyperuricemia correlated more strongly with fast eGFR decline. Diabetes, hypertension, hyperuricemia, and high baseline eGFR were associated with a decline of eGFR. Along with differential health practices, population variations in this spectrum of risk factors probably contributes to the variable CKD prevalence worldwide.

Improving CKD therapies and care: a National Dialogue

The Kidney Research National Dialogue, supported by the National Institute of Diabetes and Digestive and Kidney Diseases, asked the research and clinical communities to formulate and prioritize research objectives that would improve our understanding of kidney function and diseases. This commentary outlines the high-priority research objectives for CKD. The goal of these research objectives is to enhance knowledge to improve outcomes in people with CKD. Basic and translational research, longitudinal observations, and epidemiologic studies can each point to targets for intervention. Future interventions must be informed by data from well designed, large representative observational studies that include collection of genetic and phenotypic data as well as biospecimens. Interaction of genetic and environmental factors must be part of the analysis, including the influence of diet, comorbid conditions, and medication. The focus should be not only on slowing or preventing progression of CKD, but also on regression of disease to the greatest extent possible.

Approach to the Metabolic Implications of Peritoneal Dialysis in Acute Kidney Injury

During the 1970s and 1980s, peritoneal dialysis (PD) was widely accepted as the standard treatment for acute kidney injury (AKI). However, advances in the techniques of extracorporeal blood purification gradually reduced its use, making PD an underused modality in this context. Although PD for AKI is an underutilized modality worldwide, it is frequently used in developing countries because of its lower cost and minimal infrastructure requirements. Recent studies have shown that PD administered continuously through a flexible catheter and cycler is an effective treatment in AKI because it ensures adequate fluid status and metabolic control. However, the use of PD in AKI has several limitations, such as the need for an intact peritoneal cavity and, in emergency situations such as severe fluid overload and severe hyperkalemia, an efficacy that is lower than that with extracorporeal blood purification techniques. Metabolic, infectious, and mechanical disorders related to PD are also limitations.Among the metabolic complications of PD are hyperglycemia, hypernatremia, protein loss into the dialysate, and hypercatabolism. Hyperglycemia is caused by the use of dialysate containing high concentrations of glucose. Hypernatremia is a result of short dialysate dwell times during the rapid exchanges of high-volume PD. Protein loss into the dialysate can reach 48 g daily, worsening the nutrition status of patients already depleted by AKI. Severe hypercatabolism caused by PD remains controversial and occurs because PD methods cannot provide an adequate dialysis dose for AKI patients.Few studies have assessed the metabolic implications of PD in AKI patients. Evaluation of these implications is relatively simple, imposes no additional costs, and can provide information about the severity of the disease. Evaluation could also guide the selection of therapeutic, dialytic, and nutrition measures, preventing metabolic complications. The present manuscript describes the metabolic implications of PD and reviews the literature on how to prevent metabolic complications.

Associations between bone mineral density and subclinical atherosclerosis: a cross-sectional study of a Chinese population

CONTEXT

The significance of associations between bone mineral density (BMD) and atherosclerosis in the Asian population is less clear.

OBJECTIVE

The aim of this study was to explore the population-level associations between BMD and subclinical atherosclerosis.

DESIGN AND SETTING

This was a community-based cross-sectional study conducted in Shenyang, China.

PARTICIPANTS

A total of 385 Chinese women and men aged 37-87 years were studied.

MAIN OUTCOME MEASURES

The BMD was measured at the total hip and lumbar spine using dual-energy x-ray absorptiometry. The ankle-brachial index (ABI), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT) were measured to assess atherosclerosis. Multiple regression analysis was applied to study the associations. Multicolinearity was examined using the variance inflation factor, condition index, and variance proportions. Factor analysis and principal component regression were used to remove the problem of multicolinearity.

RESULTS

The differences of ABI, PWV, and CIMT among the normal BMD, osteopenia, and osteoporosis groups were not found. Total hip BMD was correlated with ABI in women after adjustment for age (r = 0.156). Sex-specific regression models included adjustment for age, body mass index, cigarette smoking, alcohol consumption, menopausal status (women), systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting blood glucose, serum uric acid, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and fibrinogen. Total hip BMD was associated with ABI in women after adjustment for age (per SD decrease in ABI: -0.130 g/cm(2), P = .022), but the association was borderline significant after full adjustment (P = .045). Total hip BMD and lumbar spine BMD were not associated with ABI, PWV, and CIMT after full adjustment in participants without a fracture history. The risk of osteoporosis was not associated with ABI, PWV, and CIMT.

CONCLUSIONS

Low BMD is not associated with subclinical atherosclerosis as assessed by ABI, PWV, and CIMT.

Genetic variants for type 2 diabetes and new-onset cancer in Chinese with type 2 diabetes

BACKGROUND

Diabetes is associated with an increased risk of cancer. This study aimed to evaluate associations between recently reported type 2 diabetes (T2D) susceptibility genetic variants and cancer risk in a prospective cohort of Chinese patients with T2D.

METHODS

Seven single nucleotide polymorphisms (SNP) in IGF2BP2, CDKAL1, SLC30A8, CDKN2A/B, HHEX and TCF7L2, all identified from genome-wide association studies of T2D, were genotyped in 5900 T2D patients [age mean ± SD = 57 ± 13 years, % males = 46] without any known cancer at baseline. Associations between new-onset of cancer and SNPs were tested by Cox proportional hazard models with adjustment of conventional risk factors.

RESULTS

During the mean follow-up period of 8.5 ± 3.3 years, 429 patients (7.3%) developed cancer. Of the T2D-related SNPs, the G-alleles of HHEX rs7923837 (hazard ratio [HR] (95% C.I.) = 1.34 (1.08-1.65); P = 6.7 ×10(-3) under dominant model) and TCF7L2 rs290481 (HR (95% C.I.) = 1.16 (1.01-1.33); P = 0.040 under additive model) were positively associated with cancer risk, while the G-allele of CDKAL1 rs7756992 was inversely associated (HR (95% C.I.) = 0.80 (0.65-1.00); P = 0.048 under recessive model). The risk alleles of these significant SNPs exhibited combined effect on increasing cancer risk (per-allele HR (95% C.I.) = 1.25 (1.12-1.39); P = 4.8 × 10(-5)). The adjusted cancer risk was 2.41 (95% C.I. 1.23-4.69) for patients with four risk alleles comparing to patients without risk allele.

CONCLUSIONS

T2D-related variants HHEX rs7923837, TCF7L2 rs290481 and CDKAL1 rs7756992 increased cancer risk in patients with diabetes.

IMPACT

Our findings provide novel insights into the pathogenesis of cancer in diabetes.

Serum uric acid and the risk of mortality during 23 years follow-up in the Scottish Heart Health Extended Cohort Study

BACKGROUND

Elevated uric acid is a prevalent condition with controversial health consequences. Observational studies disagree with regard to the relationship of uric acid with mortality, and with factors modifying this relationship.

OBJECTIVE

We examined the association of serum uric acid with mortality in 15,083 participants in the Scottish Heart Health Extended Cohort (SHHEC) Study.

METHODS

Serum uric acid was measured at study enrollment. Death was ascertained using both the Scottish death register and record linkage.

RESULTS

During a median follow-up of 23 years, there were 3980 deaths. In Cox proportional hazards models with sexes combined, those in the highest fifth of uric acid had significantly greater mortality (HR 1.18, 95% CI: 1.06, 1.31) compared with the second fifth, after adjustment for traditional cardiovascular risk factors. This relationship was modified by sex (P-interaction=0.002) with adjusted HRs of 1.69 (95% CI: 1.40, 2.04) and 0.99 (95% CI: 0.86, 1.14) in women and men, respectively. Compared with the second fifth, the highest fifth of uric acid was most associated with kidney-related death (HR: 2.08, 95% CI: 1.31, 3.32).

CONCLUSION

Elevated uric acid is associated with earlier mortality, especially in women. Future studies should evaluate mechanisms for these interactions and explore the strong association with renal-related mortality.

GFR estimation: from physiology to public health

Estimating glomerular filtration rate (GFR) is essential for clinical practice, research, and public health. Appropriate interpretation of estimated GFR (eGFR) requires understanding the principles of physiology, laboratory medicine, epidemiology, and biostatistics used in the development and validation of GFR estimating equations. Equations developed in diverse populations are less biased at higher GFRs than equations developed in chronic kidney disease (CKD) populations and are more appropriate for general use. Equations that include multiple endogenous filtration markers are more precise than equations including a single filtration marker. The CKD-EPI (CKD Epidemiology Collaboration) equations are the most accurate GFR estimating equations that have been evaluated in large diverse populations and are applicable for general clinical use. The 2009 CKD-EPI creatinine equation is more accurate in estimating GFR and prognosis than the 2006 MDRD (Modification of Diet in Renal Disease) Study equation and provides lower estimates of prevalence of decreased eGFR. It is useful as a "first test" for decreased eGFR and should replace the MDRD Study equation for routine reporting of serum creatinine-based eGFR by clinical laboratories. The 2012 CKD-EPI cystatin C equation is as accurate as the 2009 CKD-EPI creatinine equation in estimating GFR, does not require specification of race, and may be more accurate in patients with decreased muscle mass. The 2012 CKD-EPI creatinine-cystatin C equation is more accurate than the 2009 CKD-EPI creatinine and 2012 CKD-EPI cystatin C equations and is useful as a confirmatory test for decreased eGFR as determined by serum creatinine-based eGFR. Further improvement in GFR estimating equations will require development in more broadly representative populations, including diverse racial and ethnic groups, use of multiple filtration markers, and evaluation using statistical techniques to compare eGFR to "true GFR."

Risk factors and treatment outcomes of new contralateral upper urinary urothelial carcinoma after nephroureterectomy: the experiences of a large Chinese center

OBJECTIVE

To explore the risk factors and treatment outcomes of contralateral new upper tract urothelial carcinoma (UTUC) after nephroureterectomy in a large single-center cohort of UTUC patients.

METHODS

A retrospective analysis of the clinicopathological data of 509 consecutive patients treated by nephroureterectomy from 2000 to 2010 at a high-volume center in China was conducted.

RESULTS

Thirty-five patients (6.9%) were found to develop contralateral UTUC. Gross hematuria was a common symptom, and aristolochic acid (AA) containing Chinese herbs was identified as an underlying cause. In multivariate analysis, renal transplant recipients (HR = 16.507) and preoperative renal insufficiency (HR = 2.523) were independent risk factors. No correlation was found in the clinical and pathological characteristics of primary and subsequent contralateral UTUC. A second round of nephroureterectomy should be performed on renal transplant patients, whereas patients who are older, exhibit relatively better renal function, and have tumors that are single, located in the ureter and small size could be treated with nephron-sparing surgery. No survival difference was detected between the two treatment groups, and developing contralateral UTUC was not associated with worse survival.

CONCLUSION

Contralateral UTUC is comparatively rare, and gross hematuria is a common symptom. Renal transplant history and renal insufficiency are independent risk factors, and prophylactic contralateral nephroureterectomy is considered for uremic UTUC patients with proper renal replacement treatment or renal transplant recipients. These features are likely related to the mechanisms of multifocality of UTUC, and the potential correlation with AA remains to be elucidated. Tumor characteristics and renal function are informative for the decisions concerning surgical options for contralateral UTUC.

Derivation and validation of a prediction score for acute kidney injury in patients hospitalized with acute heart failure in a Chinese cohort

AIMS

Acute kidney injury (AKI) is a common complication among patients hospitalized for acute heart failure (AHF), and is associated with increased mortality. The goal of this study was to derive and validate a prediction score for AKI in AHF patients.

METHODS

The hospital medical records of 1709 patients with AHF were reviewed. AKI was defined as an increase in serum creatinine (SCr) of ≥26.4 μmol/L or ≥50% within 48 h. A multivariate logistic regression analysis was undertaken to develop a new prediction score. The area under the receiver operating characteristic (ROC) curve and the Hosmer-Lemeshow goodness-of-fit statistic test were calculated to assess the discrimination and calibration of the prediction score, respectively.

RESULTS

Acute kidney injury developed in 32.2% of patients with AHF. Factors independently associated with the risk of AKI included: ≥70 years of age, ≥3 previous hospital admissions for AHF, systolic blood pressure <90 mmHg, serum sodium <130 mmol/L, heart functional class IV, proteinuria, SCr ≥104 μmol/L and intravenous furosemide dose ≥80 mg/day. A prediction score for AKI was derived based on the β coefficients of each risk factor. Patients with ≥8 points would be considered at high risk for development of AKI (55.1% incidence vs 18% in those with <8 points, P < 0.001). Both the derived and validated datasets showed adequate discrimination (area under ROC curve was 0.76 in both datasets) and calibration (Hosmer-Lemeshow statistic test, P = 0.98 and 0.13, respectively).

CONCLUSION

The newly derived and validated clinical prediction score may effectively predict AKI in the patients hospitalized with AHF.

The burden of hypertension and kidney disease in Northeast India: the Institute for Indian Mother and Child noncommunicable diseases project

Chronic noncommunicable diseases (NCDs) such as hypertension, atherosclerosis, acute myocardial infarction, stroke, diabetes, obesity, and chronic kidney disease are the major cause of death not only in high income, but also in medium and low income countries. Hypertension and diabetes, the most common causes of chronic kidney disease, are particularly common in southeast Asian Countries. Because early intervention can markedly slow the progression of these two killer diseases, assessment of their presence through screening and intervention program is a priority. We summarize here results of the screening activities and the perspectives of a noncommunicable diseases project started in West Bengal, India, in collaboration with the Institute for Indian Mother and Child (IIMC), a nongovernmental voluntary organization committed to promoting child and maternal health. We started investigating hypertension and chronic kidney disease with screen in school-age children and in adults >30 years old. We found a remarkable prevalence of hypertension, even in underweight subjects, in both children and adult populations. A glomerular filtration rate <60 mL/min was found in 4.1% of adult subjects significantly higher than that of 0.8% to 1.4% reported 10 years ago. Increased awareness and intervention projects to identify NCDs and block their progression are necessary in all countries.

Plasma homocysteine is associated with aortic arterial stiffness but not wave reflection in Chinese hypertensive subjects

Objective

Elevated plasma total homocysteine (tHcy) acts synergistically with hypertension to exert a multiplicative effect on cardiovascular diseases risk. The aim of this study was to determine the relationship between tHcy concentration and blood pressure, and to evaluate the role of plasma tHcy in arterial stiffness and wave reflection in hypertension.

Methods

In this cross-sectional study, a community-based sample of 1680 subjects (mean age 61.6 years) was classified into four groups according to tHcy level (<21.6 vs. ≥21.6 µmol/l) and blood pressure (hypertensive vs. normotensive). Levels of plasma tHcy and other biochemical parameters (e.g., lipids, glucose) were determined. Central arterial blood pressure, reflected pressure wave, and carotid-femoral pulse wave velocity (cf-PWV) were assessed by tonometry within 2 days of obtaining the blood specimen.

Results

Neither peripheral nor central blood pressure differed according to tHcy levels in normotensive and hypertensive subjects. Differences in cf-PWV according to tHcy were observed only in hypertensive subjects; differences in cf-PWV in normotensive subjects were not significant after adjusting for confounding factors. Central augmentation index did not differ according to tHcy level in either normotensive or hypertensive subjects. Results of univariate analysis revealed significant correlations between blood pressure parameters and tHcy concentration only among normotensive subjects; however, these correlations were not significant in a partial correlation analysis. Results of multiple regression analysis showed that plasma tHcy levels were independently correlated with cf-PWV in hypertensive subjects (β = 0.713, P = 0.004). The independent relationship between tHcy and central augmentation index was not significant by further multiple analyses in normotensive or hypertensive individuals.

Conclusions

Plasma tHcy level is strongly and independently correlated with arterial stiffness measured as cf-PWV only in hypertensive subjects. Thus, hypertension is a major link between tHcy and aortic arterial stiffness.

Alkaline phosphatase and mortality in patients on peritoneal dialysis

BACKGROUND AND OBJECTIVES

Elevated total serum alkaline phosphatase levels have been associated with higher mortality in the general population, CKD patients, and hemodialysis patients. However, in peritoneal dialysis patients, this association has received little attention. The aim of this study was to evaluate the association between alkaline phosphatase and all-cause and cardiovascular mortality in peritoneal dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this single center retrospective cohort study, 1021 incident peritoneal dialysis patients from January 1, 2006, to December 31, 2010 with baseline serum alkaline phosphatase values were enrolled. Collected baseline data included demographic characteristics and clinical and laboratory measurements. All patients were followed until December 31, 2012. The associations of total serum alkaline phosphatase levels with all-cause and cardiovascular mortality were assessed using multivariable-adjusted Cox models.

RESULTS

Of 1021 patients, mean age was 47.5 (± 15.5) years, 59.1% of patients were men, and 22.8% of patients were diabetic. The median serum alkaline phosphatase level was 64 U/L (interquartile range=52-82 U/L). During a median 31-month (interquartile range=19-45 months) follow-up period, 203 patients died, of which 109 deaths were caused by cardiovascular disease. After adjusting for demographics, comorbid conditions, liver function, and bone metabolism parameters, the highest alkaline phosphatase quartile was significantly associated with a hazard ratio for all-cause mortality of 1.70 (95% confidence interval, 1.06 to 2.74, P=0.03) and a hazard ratio for cardiovascular mortality of 1.94 (95% confidence interval, 1.02 to 3.72, P=0.04). Each 10 U/L higher baseline alkaline phosphatase level was associated with 4% (95% confidence interval, 1.00 to 1.08, P=0.04) and 7% (95% confidence interval, 1.02 to 1.11, P=0.003) higher risk of all-cause and cardiovascular mortality, respectively.

CONCLUSION

Higher total serum alkaline phosphatase levels at the commencement of peritoneal dialysis were independently associated with all-cause and cardiovascular mortality in peritoneal dialysis patients.

Glomerular filtration rate estimation using cystatin C alone or combined with creatinine as a confirmatory test

BACKGROUND

Glomerular filtration rate (GFR) estimating equations using the combination of creatinine and cystatin C (eGFRcr-cys) are more accurate than equations using either alone (eGFRcr or eGFRcys). New guidelines suggest measuring cystatin C as a confirmatory test when eGFRcr may be inaccurate, but do not specify demographic or clinical conditions in which eGFRcys or eGFRcr-cys are more accurate than eGFRcr nor which estimate to use in such circumstances.

METHODS

We compared the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in 1119 subjects in the CKD-EPI cystatin C external validation dataset. Subgroups were defined by eGFRcr, age, sex, diabetes status and body mass index (BMI). The reference test was GFR measured using urinary or plasma clearance of exogenous filtration markers. Cystatin C and creatinine assays were traceable to primary reference materials. Accuracy was defined as the absolute difference in eGFR compared with mGFR.

RESULTS

The mean mGFR was 70 ± 41 (SD) mL/min/1.73 m(2). eGFRcys was more accurate than eGFRcr at lower BMI and less accurate at higher BMI, especially at higher levels of eGFRcr. There were small differences in accuracy in people according to the diabetes status. eGFRcr-cys was as accurate or more accurate than eGFRcr or eGFRcys in these and all other subgroups.

CONCLUSIONS

eGFRcr-cys, but not eGFRcys, is more accurate than eGFRcr in most subgroups we studied, suggesting preferential use of eGFRcr-cys when serum cystatin C is measured as a confirmatory test to obtain more accurate eGFR. Further studies are necessary to evaluate diagnostic strategies for using eGFRcys and eGFRcr-cys.

Association between kidney function and Framingham global cardiovascular disease risk score: a Chinese longitudinal study

Background

Chronic kidney disease (CKD) is generally considered an independent risk factor for cardiovascular disease (CVD) development, but rates in individuals with estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m² are uncertain. The Framingham global CVD risk score (FRS) equation is a widely accepted tool used to predict CVD risk in the general population. The purpose of the present study was to examine whether an association exists between eGFR and FRS in a Chinese population with no CKD or CVD.

Methods

A total of 333 participants were divided into three groups based on FRS. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and CKD-EPI equation for Asians (CKD-EPI-ASIA) were used to measure eGFR.

Results

A significant inverse association between eGFR and FRS was confirmed with Pearson correlation coefficients of –0.669, –0.698 (eGFR_CKD-EPI, P<0.01) and –0.658, –0.690 (eGFR_CKD-EPI-ASIA, P<0.01). This association gradually diminished with progression from the low- to high-risk groups (eGFR_CKD-EPI, r = –0.615, –0.282, –0.197, P<0.01, P<0.01, P>0.05; similar results according to the CKD-EPI-ASIA equation). In the low- or moderate-risk new-groups, this association became stronger with increased FRS (eGFR_CKD-EPI-ASIA, r = –0557, –0.622 or –0.326, –0.329, P<0.01). In contrast to the results from 2008, eGFR was independently associated with FRS following adjustment for traditional cardiovascular risk factors (P<0.05).

Conclusion

Renal function has multiple influences on predicting CVD risk in various populations. With increasing FRS and decreasing eGFR, it is also independently associated with CVD, even in individuals with eGFR >60 ml/min/1.73 m².

Estimated glomerular filtration rate is associated with both arterial stiffness and N-terminal pro-brain natriuretic peptide in newly diagnosed hypertensive patients

Even a slight decrease in the glomerular filtration rate (GFR) is an independent risk factor for cardiovascular disease. Arterial stiffness, left ventricular hypertrophy and N-terminal pro-brain natriuretic peptide (NT-proBNP) are independent risk factors for cardiovascular disease, which are particularly common in end-stage renal disease. We aimed to evaluate the association between GFR with arterial stiffness, left ventricle mass (LVM) and NT-proBNP in hypertensive subjects with normal to mildly impaired renal function. The study population consisted of 285 newly diagnosed hypertensive patients (mean age; 49.9 ± 11.8 years). GFR was estimated (eGFR) by the Modification of Diet in Renal Disease formula. Pulse wave velocity (PWV) and augmentation index (AIx), which reflects arterial stiffness, were calculated using the single-point method via the Mobil-O-Graph® ARCsolver algorithm. LVM was obtained by echocardiography. Plasma NT-proBNP was measured by electrochemiluminescence. The patients were divided into two groups according to the median eGFR value (eGFRlow group <101 ml/min/1.73 m(2) and eGFRhigh group ≥ 101 ml/min/1.73 m(2)). LVM and NT-proBNP values were higher in eGFRlow group compared with eGFRhigh group (p<0.05). Pulse wave velocity and augmentation index values were higher in eGFRlow group compared with eGFRhigh group (p<0.05, for all). Multiple linear regression analysis showed that eGFR was independently associated with PWV (β=-0.422, p<0.001) and NT-proBNP (β=-0.404, p<0.001). Present study showed that eGFR was independently associated with PWV and NT-proBNP values. Importantly, these findings may explain, in part, the increase in cardiovascular risk in with slightly impaired renal function.

Association between body mass index and cause-specific mortality as well as hospitalization in frail Chinese older adults

AIM

A U-shaped relationship between body mass index (BMI) and all-cause mortality has been reported, but there are few studies examining the association between BMI and cause-specific mortality and hospitalization. We carried out a longitudinal study to examine these associations in Chinese older adults with multiple comorbidities, which could provide a reference for the recommended BMI in this population.

METHODS

From 2004 to 2013, a retrospective cohort of Chinese older adults was selected from a geriatric day hospital in Hong Kong. They were divided into groups according to their BMI: BMI <16; BMI 16-18; BMI 18.1-20; BMI 20.1-22; BMI 22.1-24; BMI 24.1-26; BMI 26.1-28; BMI 28.1-30 and BMI >30. Other assessments included medical, functional, cognitive, social and nutritional assessment.

RESULTS

A total of 1747 older adults (mean age 80.8 ± 7.1 years, 44.1% male, 46.1% living in nursing homes, Charlson Comorbidity Index 2.0 ± 1.6) with a median follow up of 3.5 years were included. Older adults with BMI 24-28 had the lowest all-cause, infection-related and cardiovascular mortality (P < 0.001). Multivariate analysis showed that there was an inverted J-shaped association between BMI and hazard ratio for all-cause and infection-related mortality in both nursing home and community-dwelling older adults. The rate of all-cause hospitalization was lower in older adults with BMI 22-28 (P = 0.002). Multivariate analysis showed that there was an inverted J-shaped association between the odds ratio of recurrent hospitalization and BMI.

CONCLUSION

Chinese older adults with BMI 24-28 had lower all-cause mortality, infection-related mortality, cardiovascular-related mortality and all-cause hospitalization. This study provides a reference for the recommended BMI in this population.

The eGFR-C study: accuracy of glomerular filtration rate (GFR) estimation using creatinine and cystatin C and albuminuria for monitoring disease progression in patients with stage 3 chronic kidney disease--prospective longitudinal study in a multiethnic population

BACKGROUND

Uncertainty exists regarding the optimal method to estimate glomerular filtration rate (GFR) for disease detection and monitoring. Widely used GFR estimates have not been validated in British ethnic minority populations.

METHODS/DESIGN

Iohexol measured GFR will be the reference against which each estimating equation will be compared. The estimating equations will be based upon serum creatinine and/or cystatin C. The eGFR-C study has 5 components: 1) A prospective longitudinal cohort study of 1300 adults with stage 3 chronic kidney disease followed for 3 years with reference (measured) GFR and test (estimated GFR [eGFR] and urinary albumin-to-creatinine ratio) measurements at baseline and 3 years. Test measurements will also be undertaken every 6 months. The study population will include a representative sample of South-Asians and African-Caribbeans. People with diabetes and proteinuria (ACR ≥30 mg/mmol) will comprise 20-30% of the study cohort.2) A sub-study of patterns of disease progression of 375 people (125 each of Caucasian, Asian and African-Caribbean origin; in each case containing subjects at high and low risk of renal progression). Additional reference GFR measurements will be undertaken after 1 and 2 years to enable a model of disease progression and error to be built.3) A biological variability study to establish reference change values for reference and test measures.4) A modelling study of the performance of monitoring strategies on detecting progression, utilising estimates of accuracy, patterns of disease progression and estimates of measurement error from studies 1), 2) and 3).5) A comprehensive cost database for each diagnostic approach will be developed to enable cost-effectiveness modelling of the optimal strategy.The performance of the estimating equations will be evaluated by assessing bias, precision and accuracy. Data will be modelled as a linear function of time utilising all available (maximum 7) time points compared with the difference between baseline and final reference values. The percentage of participants demonstrating large error with the respective estimating equations will be compared. Predictive value of GFR estimates and albumin-to-creatinine ratio will be compared amongst subjects that do or do not show progressive kidney function decline.

DISCUSSION

The eGFR-C study will provide evidence to inform the optimal GFR estimate to be used in clinical practice.

TRIAL REGISTRATION

ISRCTN42955626.

Analysis of the prevalence rate and correlative risk factors of chronic kidney disease in physical checkups of adults in Henan area

This paper reports the results of physical examination data of a population aged 19 years and above in the Henan area. The prevalence of Chronic Kidney Disease (CKD) in adults in a healthy population and associations with potential risk factors are described. There were 556 cases with albuminuria, a prevalence rate of 5.09% (95% CI: 3.19-6.88). The prevalence rate of males (5.87%) was higher than that of females (3.81%). There were 278 cases with eGFR <60 mL/min·(1.73 m(2))(-1), suggesting a high rate of unreported CKD in this community.

Comparisons between the 2012 new CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equations and other four approved equations

OBJECTIVE

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) reported two equations in 2012: one based on cystatin C concentration (CKD-EPI2012cys) and the other using both serum creatinine and cystatin C concentrations (CKD-EPI2012Scr-cys). We compared the adaptability of new formulae with other four equations.

METHODS

Participants (n = 788; median age, 54 [range, 19-94] years) were recruited from the First Affiliated Hospital of Nanjing Medical University. The reference glomerular filtration rate (rGFR) was measured by a (99)mTc-DTPA renal dynamic imaging method, and the estimated glomerular filtration rate (eGFR) was calculated separately by the Chinese adapted Modification of Diet in Renal Disease equation (C-MDRD), MacIsaac, Ma, serum creatinine-based CKD-EPI equation (CKD-EPI2009Scr), CKD-EPI2012cys and CKD-EPI2012Scr-cys equations. We compared the performance of six equations with rGFR.

RESULTS

Median rGFR was 76.35 (interquartile range, 59.03-92.50) mL/min/1.73 m(2). Compared with CKD-EPI2009Scr, CKD-EPI2012Scr-cys formula had better diagnostic value with larger area under the receiver operating characteristic curve (ROC(AUC), 0.879, p = 0.006), especially in young participants (ROC(AUC), 0.883, p = 0.005). CKD-EPI2012cys equation did not perform better than other available equations. Accuracy (the proportion of eGFR within 30% of rGFR [P30]) of the CKD-EPI2012Scr-cys equation (77.03%) was inferior only to MacIsaac equation (80.2%) in the entire participants, but performed best in young participants with normal or mildly-injured GFR. Neither of the two new CKD-EPI equations achieved any ideal P30 in the elderly participants with moderately-severely injured GFR. Linear regression analysis demonstrated a consistent result. In this study, CKD-EPI2012Scr-cys had a relatively better diagnosis consistency of GFR stage between the eGFR and rGFR in the whole cohort.

CONCLUSION

CKD-EPI2012Scr-cys appeared less biased and more accurate in overall participants. Neither of the new CKD-EPI equations achieved ideal accuracy in senior participants with moderately-severely injured GFR. A large-scale study with more subjects and cooperating centers to develop new formulae for the elderly is assumed to be necessary.

Renal function in familial longevity: the Leiden Longevity Study

Studying renal function in subjects with a familial propensity for longevity may provide insight in (un)known mechanisms that determine the age-related decline in renal function of normal subjects. In the Leiden Longevity Study, middle-aged offspring of non-agenarian siblings and their partners as environmentally matched controls were included. Information was collected on lifestyle, medical history, medication use, and a non-fasting blood sample was drawn. Renal function (estimated glomerular filtration rate, eGFR) was assessed with the Chronic Kidney Disease epidemiology collaboration (CKD-EPI) formula. Linear mixed models were used to account for familial dependencies within the offspring and all analyses were stratified by sex. eGFR was similar between female offspring and female controls (0.44ml/min/1.73m(2) (SE 0.72) difference, p=0.54, age-adjusted). Male offspring had a higher eGFR compared to male controls (1.78ml/min/1.73m(2) (SE 0.78) difference, p=0.022, age-adjusted), and further adjustments for various characteristics did not materially change this difference. Among men with a history of hypertension, or myocardial infarction and/or stroke, offspring had a higher eGFR compared to controls (4.74ml/min/1.73m(2) (SE 1.53) difference, p=0.002, age-adjusted, and 6.21ml/min/1.73m(2) (SE 2.85) difference, p=0.033, age-adjusted, respectively). Middle-aged men, but not women, with a propensity for longevity have better renal function compared to environmentally matched controls, especially among those with a history of cardiovascular disease.

Effects of post-discharge nurse-led telephone supportive care for patients with chronic kidney disease undergoing peritoneal dialysis in China: a randomized controlled trial

BACKGROUND

Patients with end-stage renal failure (ESRF) need integrated health care to maintain a desirable quality of life. Studies suggest that post-discharge nurseled telephone support has a positive effect for patients suffering from chronic diseases. But the post-discharge care is under-developed in mainland China and the effects of post-discharge care on patients with peritoneal dialysis have not been conclusive.

AIM

The purpose of this study is to test the effectiveness of postdischarge nurse-led telephone support on patients with peritoneal dialysis in mainland China.

METHODS

A randomized controlled trial was conducted in the medical department of a regional hospital in Guangzhou. 135 patients were recruited, 69 in the study group and 66 in the control group. The control group received routine hospital discharge care. The study group received post-discharge nurse-led telephone support. The quality of life (Kidney Disease Quality of Life Short Form, KDQOL-SF), blood chemistry, complication control, readmission and clinic visit rates were observed at three time intervals: baseline before discharge (T1), 6 (T2) and 12 (T3) weeks after discharge.

RESULTS

Statistically significant effects were found for symptom/problem, work status, staff encouragement, patient satisfaction and energy/fatigue in KDQOL-SF and 84-day (12-week) clinic visit rates between the two groups. The study group had more significant improvement than the control group for sleep, staff encouragement at both T2 and T3, and pain at T2 and patient satisfaction at T3. No significant differences were observed between the two groups for the baseline measures, other dimensions in KDQOL-SF, blood chemistry, complication control, readmission rates at all time intervals and clinic visit rates at the first two time intervals.

CONCLUSIONS

Post-discharge nurse-led telephone support for patients undergoing peritoneal dialysis is effective to enhance patients' well-being in the transition from hospital to home in mainland China.

Metabolic syndrome and C-reactive protein concentration as independent correlates of chronic kidney disease

Inflammation is a common phenotype for cardiometabolic disorders. In this study, we attempted to investigate inter-relationships between metabolic syndrome (MetS), C-reactive protein (an inflammatory biomarker) and chronic kidney disease (CKD). We performed a cross-sectional analysis of data from a representative sample of 4425 Chinese adults in Taiwan. The MetS was defined by a unified criteria set by several major organizations. A CKD event was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m(2). Additionly, a CRP cutpoint of 3 mg/L was used to differentiate high and low CRP levels. Overall, 1000 participants had MetS, resulting in a prevalence rate of 22.6%. High CRP level was noted in 782 (17.6%) subjects. In addition, a total of 508 (11.5%) persons qualified as having CKD. Subjects with the MetS had 1.55-fold [95% confidence interval (CI), 1.03-2.32] increased odds of CKD compared with their counterparts without the MetS after multiple adjustments. In addition, there was a significantly graded relationship between increasing levels of serum CRP and prevalent CKD (p for trend = 0.001). Participants in the highest category of serum CRP had a significantly elevated odds of CKD as compared with those in the lowest category [odds ratio (OR), 1.60; 95% CI, 1.21-2.12]. However, there was no interaction in excess of additive scale between the presence of MetS and high CRP level (p = 0.83). These findings suggest that MetS and high CRP were independently associated with increased prevalence of CKD in Chinese adults.