Prevalence of chronic kidney disease in Thai adults: a national health survey

Background

The prevalence of patients with end stage renal disease (ESRD) who need dialysis and/or transplantation has more than doubled in Thailand during the past two decades. It has been suggested that therapeutic strategies to reduce the risk of ESRD and other complications in CKD are now available, thus the early recognition and the institution of proven therapeutic strategies are important and beneficial. We, therefore, aimed to determine the prevalence of CKD in Thai adults from the National Health Examination Survey of 2004.

Methods

Data from a nationally representative sample of 3,117 individuals aged 15 years and older was collected using questionnaires, physical examination and blood samples. Serum creatinine was measured by Jaffé method. GFR was estimated using the Chinese modified Modification of Diet in Renal Disease Study equation. Chronic kidney Disease (CKD) stages were classified based on Kidney Disease Outcome Quality Initiative (K/DOQI).

Results

The prevalence of CKD in Thai adults weighted to the 2004 Thai population by stage was 8.1% for stage 3, 0.2% and 0.15% for stage 4 and 5 respectively. Compared to non-CKD, individuals with CKD were older, had a higher level of cholesterol, and higher blood pressure. Those with cardiovascular risk factors were more likely to have CKD (stage 3-5) than those without, including hypertension (OR 1.6, 95%CI 1.1, 3.4), diabetes (OR 1.87, 95%CI 1.0, 3.4). CKD was more common in northeast (OR 2.1, 95%CI 1.3, 3.3) compared to central region. Urinalysis was not performed, therefore, we could not have data on CKD stage 1 and 2. We have no specific GFR formula for Thai population.

Conclusion

The identification of CKD patients should be evaluated and monitored for appropriate intervention for progression to kidney disease from this screening.

Sources of variation in estimates of lean body mass by creatinine kinetics and by methods based on body water or body mass index in patients on continuous peritoneal dialysis

OBJECTIVE

We identified factors that account for differences between lean body mass computed from creatinine kinetics (LBM(cr)) and from either body water (LBM(V)) or body mass index (LBM(BMI)) in patients on continuous peritoneal dialysis (CPD).

DESIGN

We compared the LBM(cr) and LBM(V) or LBM(BMI) in hypothetical subjects and actual CPD patients.

PATIENTS

We studied 439 CPD patients in Albuquerque, Pittsburgh, and Toronto, with 925 clearance studies.

INTERVENTION

Creatinine production was estimated using formulas derived in CPD patients. Body water (V) was estimated from anthropometric formulas. We calculated LBM(BMI) from a formula that estimates body composition based on body mass index. In hypothetical subjects, LBM values were calculated by varying the determinants of body composition (gender, diabetic status, age, weight, and height) one at a time, while the other determinants were kept constant. In actual CPD patients, multiple linear regression and logistic regression were used to identify factors associated with differences in the estimates of LBM (LBM(cr)<LBM(V), or LBM(cr)<LBM(BMI)).

MAIN OUTCOME MEASURE

We sought predictors of the differences LBM(V) - LBM(cr) and LBM(BMI) - LBM(cr).

RESULTS

Both LBM(V) (regardless of formula used to estimate V) and LBM(BMI) exceeded LBM(cr) in hypothetical subjects with average body compositions. The sources of differences between LBM estimates in this group involved differences in the coefficients assigned to gender, age, height, weight, presence or absence of diabetes, and serum creatinine concentration. In CPD patients, mean LBM(V) or LBM(BMI) exceeded mean LBM(cr) by 6.2 to 6.9 kg. For example, the LBM(V) obtained from one anthropometric formula was 50.4+/-10.4 kg and the LBM(cr) was 44.1+/-13.6 kg (P < .001), whereas among the 925 clearance studies, only 216 (23.3%) had LBM(cr)>LBM(V). The differences in determinants of body composition between groups with high versus low LBM(cr) were similar in hypothetical and actual CPD patients. Multivariate analysis in actual CPD patients identified serum creatinine, height, age, gender, weight, and body mass index as predictors of the differences LBM(V)-LBM(cr) and LBM(BMI)-LBM(cr).

CONCLUSIONS

Overhydration is not the sole factor accounting for the differences between LBM(cr) and either LBM(V) or LBM(BMI) in CPD patients. These differences also stem from the coefficients assigned to major determinants of body composition by the formulas estimating LBM.

Measured GFR as a confirmatory test for estimated GFR

Clinical assessment of kidney function is central to the practice of medicine. GFR is widely accepted as the best index of kidney function in health and disease, and accurate values are required for optimal decision making. Estimated GFR based on serum creatinine is now widely reported by clinical laboratories, and in most circumstances, estimated GFR is sufficient for clinical decision making. GFR estimates may be inaccurate in the non-steady state and in people in whom non-GFR determinants differ greatly from those in whom the estimating equation was developed. If GFR estimates are likely inaccurate or if decisions based on inaccurate estimates may have adverse consequences, a measured GFR is an important confirmatory test. Endogenous creatinine clearance is the most common method used to measure GFR in clinical practice but may be difficult to obtain or fraught with error. We review methods for GFR measurement using urinary and plasma clearance of exogenous filtration markers and focus on urinary clearance of iothalamate and plasma clearance of iohexol compared with inulin clearance. We suggest plasma clearance of nonradioactive markers be more widely implemented in clinical settings. Further research is necessary on the impact of the use of measured GFR as a confirmatory test.

Low LDL cholesterol, albuminuria, and statins for the risk of cancer in type 2 diabetes: the Hong Kong diabetes registry

OBJECTIVE

LDL cholesterol <2.80 mmol/l was associated with increased cancer risk in type 2 diabetes. We explored the 1) interaction between low LDL cholesterol and albuminuria and 2) interaction between copresence of these two risk factors and statin use for cancer in type 2 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed prospective data for 3,793 Chinese type 2 diabetic patients who remained naive for statin treatment and 1,483 patients in whom statin treatment was initiated during a median follow-up period of 5.24 years. All patients were free of cancer at baseline. Biological interactions were estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S). RERI > 0, AP > 0, or S > 1 indicates biological interaction.

RESULTS

In 3,793 statin-naive type 2 diabetic patients, copresence of low LDL cholesterol and albuminuria increased cancer risk by 2.8-fold (hazard ratio 2.77 [95% CI 1.78-4.31]) with significant biological interactions (RERI 1.05 [0.04-2.06]; AP 0.38 [0.09-0.66]). In the whole cohort of 5,276 type 2 diabetic patients, there was interaction between nonuse of statins and copresence of low LDL cholesterol and albuminuria with increased cancer risk (RERI 2.87 [0.64-5.09] and AP 0.60 [0.29-0.90]). Statin nonusers with LDL cholesterol <2.80 mmol/l and albumunuria had a 4.9-fold risk of cancer compared with statin users with or without both risk factors.

CONCLUSIONS

In type 2 diabetes, there was interaction between low LDL cholesterol and albuminuria with increased cancer risks. The latter was attenuated in the presence of statin treatment.

The effect of the World Kidney Day campaign on the awareness of chronic kidney disease and the status of risk factors for cardiovascular disease and renal progression

BACKGROUND

Chronic kidney disease (CKD) is a worldwide problem. We describe the trends in CKD awareness before and after the World Kidney Day (WKD) campaign and the impact of the WKD campaign in increasing awareness and appropriate management of the risk factors for cardiovascular disease and renal progression.

METHODS

We selected 57 718 people who had undergone a routine health check-up.

RESULTS

The average CKD awareness was 3.1% (95% CI: 2.6-3.7%) and was increased with progressing CKD stage. The awareness was increased from 1.1% before the WKD campaign to 5.8% after the campaign (P < 0.001). CKD awareness in the post-WKD period was increased in CKD stages 2 (OR 4.535: 95% CI: 2.044-10.062) and 3 (OR 6.614: 95% CI: 4.282-10.217) and profoundly increased in stage 4 (OR 13.800: 95% CI: 2.127-89.524), compared to the pre-WKD period. In the CKD-aware group compared to the CKD-unaware group, the awareness of diabetes mellitus (90.0% versus 54.2%, P < 0.001) and hypertension (87.2% versus 64.7%, P < 0.001) was higher and the levels of systolic blood pressure (116.9 +/- 1.0 versus 120.1 +/- 0.2, P < 0.01) and serum cholesterol (198.3 +/- 2.7 versus 205.0 +/- 0.5, P < 0.05) were lower by covariance analysis.

CONCLUSIONS

The WKD campaign had a positive impact on the awareness and control of risk factors in CKD subjects but the absolute frequency of CKD awareness still remains undesirable in Korea. We need new campaign strategies to publicize the importance of early diagnosis and appropriate management of CKD.

Plasma uric acid and hypertension in a Chinese community: prospective study and metaanalysis

BACKGROUND

Hyperuricemia has been positively associated with hypertension, but whether this association is independent of adiposity and other cardiovascular risk factors remains a matter of debate.

METHODS

We conducted a community-based prospective cohort study comprising 7220 participants (mean age 37 years; 73.8% men) in the Qingdao Port Health and Nutrition Examination Survey in China, who were free from hypertension at study entry in 1999-2000. During 4-year follow-up, 1370 men (19.0%) and 208 women (11.0%) had developed hypertension.

RESULTS

After adjustment for age, body mass index, and other covariates, the relative risks (RRs) of developing hypertension comparing the highest and lowest uric acid quartiles were 1.55 (95% CI 1.10-2.19; P for trend <0.001) for men and 1.91 (1.12-3.25; P for trend <0.001) for women. After additional adjustment for abdominal obesity, the RRs comparing the participants in the highest and lowest quartiles of uric acid were 1.39 (1.16-1.68; P for trend 0.003) for men and 1.85 (1.06-3.24; P for trend 0.006) for women. In joint analysis, compared with those in the lowest uric acid quartile and without abdominal obesity, participants who were in the highest quartile and also had abdominal obesity had a 3.0- and 3.4-fold greater risk of incident hypertension (1.56-3.97 for men and 2.10-3.81 for women, respectively).

CONCLUSIONS

These data suggest a positive association between plasma uric acid and incidence of hypertension during short-term follow-up in a Chinese population. The association between hyperuricemia and hypertension was partly mediated by abdominal obesity.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Phenotype-genotype interactions on renal function in type 2 diabetes: an analysis using structural equation modelling

AIMS/HYPOTHESIS

Cardiovascular and renal diseases share common risk factors. We used structural equation modelling (SEM) to evaluate the independent and combined effects of phenotypes and genotypes implicated in cardiovascular diseases on renal function in type 2 diabetes.

METHODS

1,188 type 2 diabetic patients were stratified into high-risk and low-risk groups according to bimodal distributions of the logarithmically transformed (log(e)) urinary albumin:creatinine ratio and plasma creatinine levels. Models for these groups, comprising continuous and non-ranking categorical data, were developed separately to evaluate the inter-relationships among measured variables and latent factors using non-linear SEMs, Bayesian estimation and model selection as assessed by a goodness-of-fit statistic.

RESULTS

Inter-correlated measured variables (obesity, glycaemia, lipid, blood pressure) and variants of the genes encoding endothelial nitric oxide synthase (NOS), beta-adrenergic receptor (ADRB), components of the renin-angiotensin system (RAS) and lipid metabolism were loaded onto their respective latent factors of phenotypes and genotypes. In addition to direct and indirect effects, latent factors of obesity, lipid and BP interacted with latent factors of ADRB and RAS genotypes to influence renal function. Together with variants of the genes encoding peroxisome proliferator-activated receptor gamma, atrial natriuretic peptide, adducin, G protein beta(3) subunit, epithelial sodium channel alpha subunit and matrix metallopeptidase 3, these parameters explained 39-80% of the variance in renal function in the high-risk and low-risk models.

CONCLUSIONS/INTERPRETATION

SEM is a useful tool for confirming and quantifying multiple interactions of biological pathways with genetic determinants. The combined and interactive effects of blood pressure, lipid and obesity on renal function may have therapeutic implications, especially in type 2 diabetic individuals with genetic risk factors.

Changes of serum and urine neutrophil gelatinase-associated lipocalin in type-2 diabetic patients with nephropathy: one year observational follow-up study

We initiated the present work to explore whether neutrophil gelatinase-associated lipocalin (NGAL) could be used to predict the progression of diabetic nephropathy in type-2 diabetic patients. Seventy-four type-2 diabetic patients were divided into normo-, micro- and macro-albuminuria groups according to their 24 h-urinary albumin excreting rate. Serum and urine NGAL, and other clinical parameters were detected. Patients were followed and measurements were repeated 1 year later. An increased tendency of urine NGAL and a decreased tendency of serum NGAL were detected, from normo-albuminuria group to macro-albuminuria group. Serum NGAL was found to rise after follow-up. Moreover, urine NGAL was found to be correlated positively with cystatin C, urea nitrogen, and serum creatinine (SCr), and inversely with glomerular filtration rate (GFR), while serum NGAL correlated negatively with cystatin C and urea nitrogen, at both baseline and follow-up levels. The results indicate that NGAL correlates closely with renal function. Both serum and urine NGAL are sensitive for predicting the progression of type-2 diabetic nephropathy but they may change differently. Serum NGAL may be more useful in early detection and urine NGAL may be more meaningful in renal function assessment.

Public health consequences of chronic kidney disease

With its rising incidence and prevalence, chronic kidney disease (CKD) is a major public health concern, both in the United States and worldwide. Recent worldwide initiatives have attempted to garner attention for CKD by emphasizing that the condition is "common, harmful, and treatable." In the United States, as many as 26 million adults may have CKD, an increase from approximately 10% of the US adult population between 1988 and 1994 to >13% just one decade later. Similar rates have been seen worldwide, with a CKD prevalence of 13% in Beijing, China and 16% in Australia. In the United States, the dramatic rise in the prevalence of CKD likely reflects similar increases in obesity and its sequelae-namely, diabetes, hypertension, and cardiovascular disease. The prevalence of CKD, as well as its associated costs, is expected to continue to increase.

Central or peripheral systolic or pulse pressure: which best relates to target organs and future mortality?

OBJECTIVE

To examine the relationship between brachial and central carotid pressures and target organ indices at baseline and their association with future mortality.

METHODS

We examined, cross-sectionally and longitudinally, the relations of baseline systolic and pulse pressures in central (calibrated tonometric carotid pulse) and peripheral (brachial, mercury sphygmomanometer) arteries to baseline left ventricular mass, carotid intima-media thickness, estimated glomerular filtration rate, and 10-year all-cause and cardiovascular mortality in 1272 participants (47% women aged 30-79 years) from a community of homogeneous Chinese.

RESULTS

Left ventricular mass was more strongly related to central and peripheral systolic pressures than pulse pressures. Intima-media thickness and glomerular filtration rate were more strongly related to central pressures than peripheral pressures. A total of 130 participants died, 37 from cardiovascular causes. In univariate analysis, all four blood pressure variables significantly predicted all-cause and cardiovascular mortality. Each blood pressure variable was entered into the multivariate models, both individually and jointly with another blood pressure variable. After adjustment for age, sex, heart rate, BMI, current smoking, glucose, ratio of total cholesterol to high-density lipoprotein cholesterol, carotid-femoral pulse wave velocity, left ventricular mass, intima-media thickness, and glomerular filtration rate, only central systolic pressure consistently and independently predicted cardiovascular mortality (hazards ratio, 1.30 per 10 mmHg). No significant sex interactions were observed in all analyses.

CONCLUSION

Systolic and pulse pressures relate differently to different target organs. Central systolic pressure is more valuable than other blood pressure variables in predicting cardiovascular mortality.

Association of kidney function with residual hypertension after treatment of aldosterone-producing adenoma

BACKGROUND

Autonomous secretion of aldosterone in patients with primary aldosteronism increases glomerular filtration rate and causes kidney damage. The influence of a mild decrease in kidney function on residual hypertension after adrenalectomy is unexplored.

STUDY DESIGN

Nonconcurrent prospective study.

SETTING & PARTICIPANTS

The study was based on the Taiwan Primary Aldosteronism Investigation (TAIPAI) database. 150 patients (61 men; overall mean age, 47.2 +/- 11.6 years) with a diagnosis of aldosterone-producing adenoma had undergone unilateral adrenalectomy at National Taiwan University Hospital from July 1999 to January 2007.

PREDICTOR

Presurgery estimated glomerular filtration rate (eGFR).

OUTCOMES & MEASUREMENTS

Residual hypertension after adrenalectomy, defined either as less than 75% of recorded blood pressure measurements with systolic blood pressure less than 140 mm Hg and diastolic blood pressure less than 90 mm Hg or requiring antihypertensive medications during the first year after surgery.

RESULTS

Before surgery, 27 (18%), 72 (48%), and 51 (34%) patients had moderately to severely decreased (<60 mL/min/1.73 m(2)), mildly decreased (60 <or= eGFR < 90 mL/min/1.73 m(2)), or nondecreased eGFR (>or=90 mL/min/1.73 m(2)), respectively. After surgery, 16 (59.3%), 29 (40.3%), and 10 (19.3%) patients in each category had postsurgery residual hypertension. Compared with patients without decreased eGFR before surgery, adjusted odds ratios for postsurgery residual hypertension were 2.7 (95% confidence interval, 1.03 to 7.0; P = 0.04) and 2.8 (95% confidence interval, 1.05 to 9.3) for mildly and moderately to severely decreased eGFR, respectively.

LIMITATIONS

Arbitrary definition for residual hypertension.

CONCLUSIONS

Two-thirds of patients with aldosterone-producing adenoma were cured of hypertension by means of unilateral adrenalectomy. Kidney function impairment, even mild, appears to be associated with a high incidence of postsurgery residual hypertension.

Prevalence and risk factors of albuminuria and chronic kidney disease in Chinese population with type 2 diabetes and impaired glucose regulation: Shanghai diabetic complications study (SHDCS)

BACKGROUND

Diabetes is a major risk factor for the development of kidney disease. We aimed to determine the prevalence of albuminuria and chronic kidney disease (CKD) in Chinese subjects with diabetes and pre-diabetes and the risk factors for kidney disease.

METHODS

An urban community-based sample of 3714 adults in Shanghai was classified into normal glucose tolerance (NGT), impaired glucose regulation (IGR) and diabetes. The estimated glomerular filtration rate (eGFR) and the urinary albumin-to-creatinine ratio (ACR) were applied to designate renal function and albuminuria, respectively. Binary logistic regression was performed to analyse the contribution of risk factors to CKD. Polynominal regression was used to determine the trends of eGFR with the increment of ACR.

RESULTS

The prevalence of microalbuminuria, macroalbuminuria and CKD in subjects with diabetes was 22.8%, 3.4% and 29.6%, respectively, which was significantly higher than that in non-diabetes subjects. After adjustment for age, the odds ratio of hypertension for albuminuria and renal insufficiency (eGFR <60 mL/min/1.73 m(2,) stages 3-5 of CKD) were 1.23 (P = 0.000) and 2.55 (P = 0.000). Diabetes and cardiovascular disease (CVD) both increased the risk for albuminuria significantly, with the odds ratio of 1.22 (P = 0.04) and 1.36 (P = 0.006), respectively. Diabetes and CVD were not independent risk factor for renal insufficiency. Although the worsening trends of eGFR are similar in diabetes and IGR subjects, IGR was not a significant risk factor for albuminuria and renal insufficiency.

CONCLUSION

Screening for albuminuria and eGFR is highly recommended for older patients with diabetes, hypertension and CVD to prevent end-stage kidney disease.

Long-term prognosis of Chinese patients with a lacunar infarct associated with small vessel disease: a five-year longitudinal study

RATIONALE

Lacunar infarct associated with small vessel disease is a common stroke subtype in China and has a favorable short-term prognosis. Data on its long-term prognosis among Chinese patients are lacking.

AIMS

We aimed to study its long-term prognosis and predictors for poor outcomes.

DESIGN

We followed up to 75 consecutive Chinese stroke patients who had a lacunar infarct for a period of 5 years. Clinical outcomes with respect to mortality and recurrent stroke were noted. We evaluated baseline clinical and imaging predictors for such outcomes using the Cox regression analysis.

STUDY OUTCOMES

Sixteen (21.3%) patients died and 12 (16%) patients had recurrent stroke during follow-up. Twenty-one (28%) patients had combined events of either death and/or recurrent stroke. Univariate Cox regression analysis showed that age, literacy, National Institute of Health Stroke Scale, incident stroke/transient ischemic attack, and white matter lesion volume predicted survival, while, age, National Institute of Health Stroke Scale, systolic blood pressure, hyperhomocysteinemia, silent lacunes, microbleeds, and white matter lesion volume predicted recurrent stroke. Multivariate Cox regression analysis showed that National Institute of Health Stroke Scale (HR 1.25, 95% CI 1.05-1.48) and white matter lesion volume (HR 1.46, 95% CI 1.11-1.92) predicted combined events of mortality and/or recurrent stroke after age adjustment.

CONCLUSION

Approximately one in four patients either died and/or had recurrent stroke within 5 years after a lacunar infarct. Age, stroke severity, and volume of white matter lesion predict a poor long-term prognosis.

Association between metabolic syndrome and chronic kidney disease in the Korean population

AIM

We performed a retrospective study to examine the association between the metabolic syndrome (MS)and risk for the development of chronic kidney disease (CKD).

METHODS

This cohort study included 60 921 healthy adults recruited from two health promotion centres.Anthropometric measures, blood pressure, fasting glucose, lipid profile and serum creatinine were evaluated. The glomerular filtration rate was estimated (eGFR) using the abbreviated equation developed by the Modification of Diet in Renal Disease (MDRD) formula. CKD was defined as an eGFR of <60 mL/min per 1.73 m2 or the presence of proteinuria.

RESULTS

The prevalence of MS and CKD was 19.0% and 7.2% respectively. Those with MS had a higher prevalence of CKD (11.0% vs 6.3%, P < 0.001) than those without MS. As the number of MS components increased, the prevalence of CKD increased and the eGFR decreased. The multiple linear analyses showed that each of the components of the MS was negatively correlated with the eGFR. Unadjusted and multivariate adjusted associations were identified between MS and CKD. Individuals with MS had a multivariate adjusted odds ratio of 1.680 (95% confidence interval, 0.566-1.801) for CKD compared with those without MS.

CONCLUSION

Our findings, which were obtained from a large Korean cohort, suggest that MS was associated with CKD.

Clinical characteristics and outcomes of rural patients with ESRD in Guangxi, China: one dialysis center experience

OBJECTIVES

End-stage renal disease (ESRD) is a serious public health problem in Guangxi, a province of south China. This prospective study evaluated the characteristics and outcome of rural patients with ESRD in a dialysis center of Guangxi, compared with urban patients in the same period.

METHODS

A total of 238 patients (96 rural and 142 urban) who enrolled in 2007 was included in this study and followed up for 1 year. Clinical data including patient basic information, clinical parameters, laboratory tests, data associated with dialysis and prognosis were evaluated and compared between rural and urban groups.

RESULTS

Glomerulonephritis was found to be the most common cause of ESRD in all the cohorts studied, with similar rates of 47.9 and 46.5% in the rural and urban patients, respectively. Compared to urban patients, the rural patients had significantly lower prevalence of diabetic nephropathy (8.3 vs. 24.6%, P < 0.001) and higher prevalence of obstructive uropathy (20.8 vs. 3.5%, P < 0.001); the rural patients were overall younger, with poorer financial supports, but with higher rates of late referrals, poorer renal functions as indicated by related laboratory tests including lower levels of GFR, serum hemoglobin, bicarbonate and Kt/V, but higher prevalence of very low GFR, severe metabolic acidosis, severe anemia and hyperkalemia, higher rate of not initiating dialysis, radial artery puncture and mortality. The cardiovascular events were found to be the most common cause of death in both rural and urban groups.

CONCLUSIONS

Glomerulonephritis was found to be the most common cause of ESRD in all the studied patients. The rural patients with ESRD in Guangxi had kidney disease in more advanced stage at the time of first visit to a nephrologist and higher rates of mortality after dialysis initiation, compared to urban patients.

Drug Dosage Adjustment Using Renal Estimation Equations: A Review of the Literature

Purpose

To examine the factors affecting drug clearance and the available evidence for drug dosing based on the Cockcroft-Gault (CG) equation and the abbreviated Modification of Diet in Renal Disease (abbrMDRD) equation. Factors that would distort the accuracy of these formulas and the affect of this distortion on the use of either formula in drug dosage adjustment were reviewed.

Methods

An updated review of the literature was performed that pertained to the accuracy of the CG and abbrMDRD equations and their use in drug dosage adjustment. MEDLINE was searched using the OVIDSP database, from the inception of the database (1950) through June 2008.

Discussion

To cover the major issues concerning the use of renal estimation equations in drug dosing adjustment, various areas were examined. Topics included the accuracy of the CG and abbrMDRD formulas, variability in these equations because of patient and laboratory factors, the isotope dilution-mass spectrometry standardization initiative, and the applicability of each formula to modifying medication doses.

Conclusion

Although the abbrMDRD equation has many advantages as compared with the CG equation, too little research has been completed at this time to recommend the clinical use of the abbrMDRD equation in pharmacy practice.

The Joint Asia Diabetes Evaluation (JADE) Program: a web-based program to translate evidence to clinical practice in Type 2 diabetes

AIMS

The Joint Asia Diabetes Evaluation (JADE) Program is the first web-based program incorporating a comprehensive risk engine, care protocols, clinical decision and self-management support to improve ambulatory diabetes care. The aim was to validate the risk stratification system of the JADE Program using a large prospective cohort.

METHODS

The JADE interactive risk engine stratifies patients into different risk levels using results from an annual comprehensive assessment of complications and risk factors. We used a prospective registry consisting of 7534 Type 2 diabetic patients [45.6% men, median (range) age 57 years (13-92)] to perform internal validation of the risk engine.

RESULTS

The JADE Risk Engine categorized patients into four risk levels (from low to high): level 1, n = 4520 (6%); level 2, n = 1468 (19.5%); level 3, n = 4476 (59.4%); and level 4, n = 1138 (15.1%). After a median follow-up period of 5.5 years (mean +/- sd 5.4 +/- 2.81 years), 763 (10.1%) died, 1129 (14.9%) developed cardiovascular disease (CVD), 282 (3.7%) developed end-stage renal disease and 1400 (18.6%) had at least one of these events. Compared with risk level 1, levels 2, 3 and 4 were associated with 2.8-, 4.7- and 8.6-fold increased risk of clinical end-points. Risk levels 3 and 4 were, respectively, associated with 2.2- and 3.9-fold increased risk for all-cause death and 4.8- and 12.1-fold increased CVD risks.

CONCLUSION

Based on results from a comprehensive assessment, the JADE Risk Engine successfully categorizes patients into different risk levels to guide clinical management.

Carotid vascular remodelling in patients with autosomal dominant polycystic kidney disease

AIM

To study carotid vascular wall remodelling in patients with autosomal dominant polycystic kidney disease (ADPKD) using integrated backscatter signal (IBS) analysis.

METHODS

Included in the study were: 60 ADPKD patients with preserved renal function, including 32 patient with hypertension and 28 with normotension; 25 patients with essential hypertension; and 30 healthy volunteers. Carotid intima-media thickness (IMT) was measured by 2-D conventional ultrasonography. Acoustic tissue characterization of the carotid wall was assessed by IBS analysis, and the percentage of regions considered as fibromatosis was calculated in all groups.

RESULTS

Carotid IMT in hypertensive ADPKD patients (0.8 +/- 0.05 vs 0.68 +/- 0.02 mm, P < 0.01 and 0.8 +/- 0.05 vs 0.56 +/- 0.04 mm, P < 0.01 respectively) and patients with essential hypertension (0.79 +/- 0.03 vs 0.68 +/- 0.02 mm, P < 0.01 and 0.79 +/- 0.03 vs 0.56 +/- 0.0 4 mm, P < 0.01 respectively) was significantly greater than that of normotensive patients and healthy subjects. Carotid IMT in normotensive ADPKD patients was also significantly greater than that in healthy subjects (0.68 +/- 0.02 vs 0.56 +/- 0.04 mm, P < 0.01). Calibrated IBS (C-IBS) in hypertensive ADPKD patients was significantly greater than that in patients with essential hypertension and normotensive ADPKD patients (-21.2 +/- 1.51 dB vs -23.1 +/- 1.61 dB, P < 0.05; -21.2 +/- 1.51 dB vs -24.5 +/- 1.34 dB, P < 0.01). C-IBS in normotensive ADPKD patients was significantly greater than that in healthy subjects (-24.5 +/- 1.34 dB vs -26.2 +/- 1.69 dB, P < 0.01). The percentage of regions that could be considered as fibromatosis in hypertensive ADPKD patients was significantly greater than that in patients with essential hypertension and normotensive ADPKD patients (30.0% vs 22.4%, P < 0.05; 30.0% vs 17.9%, P < 0.01). The percentage of regions that could be considered as fibromatosis in normotensive ADPKD patients was significantly greater than that in healthy subjects (15.2% vs 10.3%, P < 0.01).

CONCLUSION

Carotid remodelling occurs in the early stage of ADPKD and can be aggravated by hypertension. Fibrosis contributes to the vascular rearrangement.

End-stage renal disease in Taiwan: a case-control study

Background

Taiwan has the highest incidence of end-stage renal disease (ESRD) in the world. The epidemiologic features of ESRD, however, have not been investigated. In this case–control study, we evaluated the risk of ESRD associated with a number of putative risk factors.

Methods

We studied 200 patients among whom ESRD had been newly diagnosed between 1 January 2005 and 31 December 2005; 200 controls were selected from among relatives of patients treated in the general surgery unit. Using a structured questionnaire, we collected information related to socioeconomic factors, history of disease, regular blood or urine screening, lifestyle, environmental exposure, consumption of vitamin supplements, and regular drug use at 5 years before disease onset.

Results

Our primary multivariate risk models indicated that low socioeconomic status was a strong predictor of ESRD (education: odds ratio [OR], 2.78; 95% confidence interval [CI], 1.49–5.19; income: OR, 2.86, 95% CI, 1.48–5.52), even after adjusting for other risk factors. Other significant predictors for ESRD were a history of hypertension (OR, 3.63–3.90), history of diabetes (OR, 3.85–5.50), and regular intake of folk remedies or over-the-counter Chinese herbs (OR, 10.84–12.51). Regular intake of a multivitamin supplement 5 years before diagnosis was associated with a decreased risk of ESRD (OR, 0.12–0.14).

Conclusions

Our findings indicate that low socioeconomic status, history of hypertension, diabetes, and regular use of folk remedies or over-the-counter Chinese herbs were significant risk factors for ESRD, while regular intake of a multivitamin supplement was associated with a decreased risk of ESRD.

Serum uric acid is independently associated with metabolic syndrome in subjects with and without a low estimated glomerular filtration rate

OBJECTIVE

The relationship among serum uric acid (SUA), metabolic syndrome, and chronic kidney disease (CKD) is unclear. We examined whether SUA level is an independent risk factor for chronic kidney disease and whether the association between SUA and metabolic syndrome is affected by kidney function.

METHODS

We analyzed 28,745 subjects (17,478 men, 11,267 women, age 20-49 yrs) who underwent health examinations at this hospital between 2000 and 2007. Hyperuricemia was defined as SUA level > 7.7 mg/dl in men or > 6.6 mg/dl in women. Kidney function was assessed by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study equation modified for Chinese subjects. Impaired renal function with low GFR was defined as eGFR < 90 ml/min/1.73 m(2). The UA-low GFR groups were defined according to the observed combination of hyperuricemia and low GFR: Group A (absence of both hyperuricemia and low GFR); Group B (presence of low GFR but no hyperuricemia); Group C (presence of hyperuricemia but not low GFR); and Group D (presence of both hyperuricemia and low GFR).

RESULTS

The prevalence of hyperuricemia, metabolic syndrome, and impaired kidney function with low GFR was 20.3% (27.6% in men, 8.9% in women), 7.6% (10.6% in men, 3.0% in women), and 9.9% (11.6% in men, 7.1% in women), respectively. The Pearson correlation between SUA and eGFR was only -0.26 (-0.21 in men, -0.22 in women; p < 0.001). In men, the age-adjusted odds ratio (OR) of metabolic syndrome was 1.41 (Group B), 2.45 (Group C), and 2.58 (Group D) in comparison with Group A. In women, the age-adjusted OR of metabolic syndrome was 0.83 (Group B), 5.47 (Group C), and 3.31 (Group D) in comparison with Group A.

CONCLUSION

Hyperuricemia is prevalent in the Taiwan population. Hyperuricemia is only weakly associated with renal function, but is strongly associated with metabolic syndrome with or without a low eGFR.

Prevalence of chronic kidney disease in the Japanese general population

BACKGROUND

We previously estimated the prevalence of chronic kidney disease (CKD) stages 3-5 at 19.1 million based on data from the Japanese annual health check program for 2000-2004 using the Modification of Diet in Renal Disease (MDRD) equation multiplied by the coefficient 0.881 for the Japanese population. However, this equation underestimates the GFR, particularly for glomerular filtration rates (GFRs) of over 60 ml/min/1.73 m(2). We did not classify the participants as CKD stages 1 and 2 because we did not obtain proteinuria data for all of the participants. We re-estimated the prevalence of CKD by measuring proteinuria using a dipstick test and by calculating the GFR using a new equation that estimates GFR based on data from the Japanese annual health check program in 2005.

METHODS

Data were obtained for 574,024 (male 240,594, female 333,430) participants over 20 years old taken from the general adult population, who were from 11 different prefectures in Japan (Hokkaido, Yamagata, Fukushima, Tochigi, Ibaraki, Tokyo, Kanazawa, Osaka, Fukuoka, Miyazaki and Okinawa) and took part in the annual health check program in 2005. The glomerular filtration rate (GFR) of each participant was computed from the serum creatinine value using a new equation: GFR (ml/min/1.73 m(2)) = 194 x Age(-0.287) x S-Cr(-1.094) (if female x 0.739). The CKD population nationwide was calculated using census data from 2005. We also recalculated the prevalence of CKD in Japan assuming that the age composition of the population was same as that in the USA.

RESULTS

The prevalence of CKD stages 1, 2, 3, and 4 + 5 were 0.6, 1.7, 10.4 and 0.2% in the study population, which resulted in predictions of 0.6, 1.7, 10.7 and 0.2 million patients, respectively, nationwide. The prevalence of low GFR was significantly higher in the hypertensive and proteinuric populations than it was in the populations without proteinuria or hypertension. The prevalence rate of CKD in Japan was similar to that in the USA when the Japanese general population was age adjusted to the US 2005 population estimate.

CONCLUSION

About 13% of the Japanese adult population-approximately 13.3 million people-were predicted to have CKD in 2005.

Revised equations for estimated GFR from serum creatinine in Japan

BACKGROUND

Estimation of glomerular filtration rate (GFR) is limited by differences in creatinine generation among ethnicities. Our previously reported GFR-estimating equations for Japanese had limitations because all participants had a GFR less than 90 mL/min/1.73 m2 and serum creatinine was assayed in different laboratories.

STUDY DESIGN

Diagnostic test study using a prospective cross-sectional design. New equations were developed in 413 participants and validated in 350 participants. All samples were assayed in a central laboratory.

SETTING & PARTICIPANTS

Hospitalized Japanese patients in 80 medical centers. Patients had not participated in the previous study.

REFERENCE TEST

Measured GFR (mGFR) computed from inulin clearance.

INDEX TEST

Estimated GFR (eGFR) by using the modified isotope dilution mass spectrometry (IDMS)-traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation using the previous Japanese Society of Nephrology Chronic Kidney Disease Initiative (JSN-CKDI) coefficient of 0.741 (equation 1), the previous JSN-CKDI equation (equation 2), and new equations derived in the development data set: modified MDRD Study using a new Japanese coefficient (equation 3), and a 3-variable Japanese equation (equation 4).

MEASUREMENTS

Performance of equations was assessed by means of bias (eGFR - mGFR), accuracy (percentage of estimates within 15% or 30% of mGFR), root mean squared error, and correlation coefficient.

RESULTS

In the development data set, the new Japanese coefficient was 0.808 (95% confidence interval, 0.728 to 0.829) for the IDMS-MDRD Study equation (equation 3), and the 3-variable Japanese equation (equation 4) was eGFR (mL/min/1.73 m2) = 194 x Serum creatinine(-1.094) x Age(-0.287) x 0.739 (if female). In the validation data set, bias was -1.3 +/- 19.4 versus -5.9 +/- 19.0 mL/min/1.73 m2 (P = 0.002), and accuracy within 30% of mGFR was 73% versus 72% (P = 0.6) for equation 3 versus equation 1 and -2.1 +/- 19.0 versus -7.9 +/- 18.7 mL/min/1.73 m(2) (P < 0.001) and 75% versus 73% (P = 0.06) for equation 4 versus equation 2 (P = 0.06), respectively.

LIMITATION

Most study participants had chronic kidney disease, and some may have had changing GFRs.

CONCLUSION

The new Japanese coefficient for the modified IDMS-MDRD Study equation and the new Japanese equation are more accurate for the Japanese population than the previously reported equations.

Effects of systolic and diastolic blood pressures on incident coronary heart disease and all-cause death in Chinese women with Type 2 diabetes: the Hong Kong Diabetes Registry

BACKGROUND

Elevated blood pressure (BP) is an important risk factor for the development of coronary heart disease (CHD), although the threshold above which the risk increases has not been clearly defined. The aim of the present study was to examine the full-range association between BP and CHD.

METHODS

A prospective cohort of 3861 Chinese women with Type 2 diabetes mellitus (T2DM) was followed for a median of 5.61 years. Restricted cubic spline analysis was used to examine the relationship between BP and CHD.

RESULTS

Subjects who developed CHD were older, more likely to be smokers, had a significantly longer duration of diabetes, higher systolic BP (SBP), glycated hemoglobin, albuminuria, low-density lipoprotein-cholesterol, and triglycerides, and lower estimated glomerular filtration rate and high-density lipoprotein-cholesterol. Mortality was higher in those who developed CHD compared with those who did not, with all-cause death in 30.2% and 7.8% of patients, respectively. Over 21,641 and 22 049 person-years follow up, 4.4% of patients (n = 169) developed CHD and 8.8% (n = 340) died, respectively. The relative risk of SBP for CHD was constant up to 120 mmHg, after which it started to rise: from 130 mmHg, each 10-mmHg increase in SBP was associated with a 1.13-fold increased risk of CHD.

CONCLUSIONS

We identified 130 mmHg as the threshold of SBP for increased risk of CHD in Chinese female patients with T2DM. It appears that 67-77 mmHg is the optimal range for diastolic BP, within which the risk of CHD is lowest.

[Occult renal disease and drug prescription in primary care]

OBJECTIVE

To study the prevalence of chronic kidney disease (CKD) [glomerular filtration rate (GFR) <60ml/min/1.73m(2)] and occult kidney disease (OKD) (normal serum creatinine values with GFR <60) in elderly patients.

DESIGN

Retrospective, observational study.

SETTING

Four primary care centres in the province of Huesca, Spain.

PARTICIPANTS

About 4014 patients older than 65 years were randomly selected.

MAIN MEASUREMENTS

GFR was calculated for all subjects using the four-variable modified MDRD equation. We registered all drugs prescriptions to the patients during a period of twelve months focusing on the potential nephrotoxic drugs.

RESULTS

After exclusions, GFR was estimated in 3286 patients (1424 men of 75.49+/-6.6 years and 1862 women of 76.29+/-7.04 years; P=.001). The prevalence of CKD was 21.2%. A total of 10.1% of patients (12.8% of women and 6.44% of men) had OKD. We recorded the complete drug prescription in 269 patients. Mean of all different drugs that were prescribed by patient-year was 10.69+/-5.92 (men 9.55+/-5.57 and women 11.11+/-6; P=.05)]. A large number of patients were treated with potentially dangerous drugs, particularly the non-steroidal anti-inflammatory drugs with 165 cases (61.34%), and 72% were exposed to drugs that can lead to hyperkalaemia.

CONCLUSIONS

We conclude that GFR estimation by clinical laboratories in the setting of primary care can contribute to prevent the adverse effects of inappropriate drug prescriptions.

Relation of adiponectin and high-sensitivity C-reactive protein to pulse-wave velocity and N-terminal pro-B-type natriuretic peptide in the general population

The roles of metabolic syndrome and chronic subclinical inflammation in arterial stiffening and the development of heart failure remain to be elucidated. Whether adiponectin and high-sensitivity C-reactive protein (hs-CRP) were independently related to brachial-ankle pulse-wave velocity (ba-PWV) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in the general population were investigated. Eligible study subjects were 445 Chinese residents aged > or =40 years who participated in a community-based survey, underwent examination of ba-PWV, and had complete data of serum adiponectin, hs-CRP (<10 mg/L), and NT-pro-BNP. Adiponectin, but not hs-CRP, was independently related to ba-PWV (standardized regression parameter -0.107, p <0.05) when age, gender, body mass index, and number of metabolic syndrome components were accounted for. On the other hand, ba-PWV, adiponectin, and hs-CRP were independently related to NT-pro-BNP (standardized regression parameters 0.116, 0.188, and 0.094, respectively; all p <0.05) when age, gender, body mass index, number of metabolic syndrome components, and renal function were accounted for. In conclusion, adiponectin, but not hs-CRP, is independently associated with both ba-PWV and NT-pro-BNP in the general population. Because adiponectin, hs-CRP, ba-PWV, and NT-pro-BNP may represent markers for metabolic syndrome, chronic subclinical inflammation, arterial stiffness, and ventricular dysfunction, respectively, our results suggest that adiponectin may directly modulate both arterial stiffening and ventricular dysfunction. In contrast, hs-CRP may independently contribute to ventricular dysfunction, but not arterial stiffening.

Effect of interactions between C peptide levels and insulin treatment on clinical outcomes among patients with type 2 diabetes mellitus

BACKGROUND

A recently halted clinical trial showed that intensive treatment of type 2 diabetes mellitus was associated with increased mortality. Given the phenotypic heterogeneity of diabetes, therapy targeted at insulin status may maximize benefits and minimize harm.

METHODS

In this longitudinal cohort study, we followed 503 patients with type 2 diabetes who were free of cardiovascular disease from 1996 until data on mortality and cardiovascular outcomes were censored in 2005. Phenotype-targeted therapy was defined as use of insulin therapy in patients with a fasting plasma C peptide level of 0.2 nmol/L or less and no insulin therapy in patients with higher C peptide levels.

RESULTS

The mean age of the cohort was 54.4 (standard deviation 13.1) years, and 56% were women. The mean duration of diabetes was 4.6 years (range 0-35.9 years). Of the 503 patients, 110 (21.9%) had a low C peptide level and 111 (22.1%) were given insulin. Based on their C peptide status, 338 patients (67.2%) received phenotype-targeted therapy (non-insulin-treated, high C peptide level [n = 310] or insulin-treated, low C peptide level [n = 28]), and 165 patients (32.8%) received non-phenotype-targeted therapy (non-insulin-treated, low C peptide level [n = 82] or insulin-treated, high C peptide level [n = 83]). Compared with the insulin-treated, low-C-peptide referent group, the insulin-treated, high-C-peptide group was at a significantly higher risk of cardiovascular events (hazard ratio [HR] 2.85, p = 0.049) and death (HR 3.43, p = 0.043); the risk was not significantly higher in the other 2 groups. These differences were no longer significant after adjusting for age, sex and diabetes duration.

INTERPRETATION

Patients with low C peptide levels who received insulin had the best clinical outcomes. Patients with normal to high C peptide levels who received insulin had the worst clinical outcomes. The results suggest that phenotype-targeted insulin therapy may be important in treating diabetes.

Changes of serum and urine neutrophil gelatinase-associated lipocalin in type-2 diabetic patients with nephropathy: one year observational follow-up study

We initiated the present work to explore whether neutrophil gelatinase-associated lipocalin (NGAL) could be used to predict the progression of diabetic nephropathy in type-2 diabetic patients. Seventy-four type-2 diabetic patients were divided into normo-, micro- and macro-albuminuria groups according to their 24 h-urinary albumin excreting rate. Serum and urine NGAL, and other clinical parameters were detected. Patients were followed and measurements were repeated 1 year later. An increased tendency of urine NGAL and a decreased tendency of serum NGAL were detected, from normo-albuminuria group to macro-albuminuria group. Serum NGAL was found to rise after follow-up. Moreover, urine NGAL was found to be correlated positively with cystatin C, urea nitrogen, and serum creatinine (SCr), and inversely with glomerular filtration rate (GFR), while serum NGAL correlated negatively with cystatin C and urea nitrogen, at both baseline and follow-up levels. The results indicate that NGAL correlates closely with renal function. Both serum and urine NGAL are sensitive for predicting the progression of type-2 diabetic nephropathy but they may change differently. Serum NGAL may be more useful in early detection and urine NGAL may be more meaningful in renal function assessment.

Concise semiquantitative histological scoring system for immunoglobulin A nephropathy

AIM

Immunoglobulin A nephropathy (IgAN) is a common and progressive glomerulonephritis. Histological lesions of IgAN are variable and considered as a risk factor for renal outcome. Establishing a relatively concise histological semiquantitative scoring system would be valuable in clinical practice.

METHODS

Renal biopsy sections of 293 patients with primary IgAN from two centres in China were reviewed. A histological scoring system was established based on multivariate survival analysis of semiquantitative histological indices, using end-stage renal disease (ESRD) as the end-point event.

RESULTS

Four indices--extracapillary glomerular activity index (exGAI), mesangial proliferation index (MsI), glomerular chronicity index (GCI) and tubulointerstitial chronicity index (TCI)--independently correlated with ESRD (relative risk (RR) = 1.16, 2.27, 1.29 and 1.80, respectively). The four indices and the sum of their scores (Total I) constituted the scoring system. Patients with exGAI of 4 or more, GCI of 4 or more, MsI of 2 or more and TCI of 2 or more were considered as having a higher risk for progression (P < 0.05). A score of 4 or more on the exGAI index could identify the patients who should be treated with immunosuppressive drugs, which showed a lower incidence of ESRD than that without (24.3% vs 52.4%, P = 0.031).

CONCLUSION

It suggested that the present concise scoring system could serve as prognostic and therapeutic indications.

Predictivity of survival according to different equations for estimating renal function in community-dwelling elderly subjects

BACKGROUND

Detection of subjects with early chronic kidney disease (CKD) is important because some will progress up to stage 5 CKD, and most are at high risk of cardiovascular morbidity and mortality. While validity and precision of estimated glomerular filtration rate (eGFR) equations in tracking true GFR have been repeatedly investigated, their prognostic performance for mortality has not been hitherto compared. This is especially relevant in an elderly population in whom the risk of death is far more common than progression.

METHODS

We analysed data of participants in the InCHIANTI study, a community-based cohort study of older adults. Twenty-four-hour creatinine clearance (Ccr), Cockcroft-Gault (C-G) and Modification of Diet in Renal Disease (MDRD)-derived equations (six and four input variables) were calculated at enrolment (1998-2000), and all-cause mortality and cardiovascular mortality were prospectively ascertained by Cox regression over a 6-year follow-up.

RESULTS

Of the 1270 participants, 942 (mean age 75 years) had complete data for this study. The mean renal function ranged from 77 ml/min/1.73 m(2) by Ccr to 64 ml/min/1.73 m(2) by C-G. Comparisons among equations using K/DOQI staging highlight relevant mismatches, with a prevalence of CKD ranging from 22% (MDRD-4) to 40% (C-G). Reduced renal function was a strong independent predictor of death. In a Cox model--adjusted for demographics, physical activity, comorbidities, proteinuria and inflammatory parameters-participants with Ccr 60-90 ml/min/1.73 m(2) and Ccr <60 ml/min/1.73 m(2) were, respectively, 1.70 (95% CI: 1.02-2.83) and 1.91 (95% CI: 1.11-3.29) times more likely to die over the follow-up compared to those with Ccr >90 ml/min/1.73 m(2). For the C-G, the group with values <60 ml/min/1.73 m(2) had a significant higher all-cause mortality compared to those with values >90 ml/min/1.73 m(2) (HR 2.59, 95% CI: 1.13-5.91). The classification based on the MDRD formulae did not provide any significant prognostic information. The adjusted risk of all-cause mortality followed a similar pattern when Ccr and estimating equations were introduced as continuous variables or dichotomized as higher or lower than 60 ml/min. C-G was the best prognostic indicator of cardiovascular mortality. Possibly, Ccr and C-G are better prognostic indicators than MDRD-derived equations because they incorporate a stronger effect of age.

CONCLUSIONS

In a South-European elderly population, the prevalence of CKD is high and varies widely according to the method adopted to estimate GFR. Researchers and clinicians who want to capture the prognostic information on mortality related to kidney function should use the Ccr or C-G formula and not MDRD equations. These results highlight the importance of strategies for early detection and clinical management of CKD in elderly subjects.

Comparison of the prevalence of chronic kidney disease among different ethnicities: Beijing CKD survey and American NHANES

BACKGROUND

It is unclear whether ethnic disparity of the prevalence of chronic kidney disease (CKD) exists among native Chinese and American ethnicities.

METHODS

A stratified multistage clustered screening for CKD performed in Beijing in 2006 was compared with data from the National Health and Nutrition Examination Survey (NHANES) between 1999-2006 (participants aged > or =20 years, 13 626 Chinese, 9006 whites, 3447 African Americans, 4626 Hispanics). Serum creatinine from Beijing and NHANES were calibrated at the Cleveland Clinic Laboratory. The re-expressed abbreviated MDRD equation for Americans and its modified form for Chinese were used to estimate glomerular filtration rate (eGFR). Subjects with eGFR <60 mL/min/1.73 m(2) were diagnosed as having chronic renal insufficiency (CRI). Albuminuria was diagnosed if the urine albumin-creatinine ratio was >17 mg/g for males or >25 mg/g for females. CKD was diagnosed if CRI or albuminuria was present.

RESULTS

Compared with American whites, African Americans and Hispanics, Chinese had a lower prevalence of adjusted albuminuria (12.10%, 16.33% and 14.16% versus 9.27%), CRI (9.46%, 5.18% and 3.11% versus 1.38%) and CKD (19.03%, 19.00% and 15.99% versus 10.25%). Moreover, Chinese hold the lowest risk of albuminuria when exposed to diabetes; the risk of CRI among Chinese when exposed to diabetes or hypertension was lower than that among African Americans, but similar to that among whites and Hispanics.

CONCLUSIONS

The CKD prevalence was significantly different among native Chinese and American ethnicities.