Albumin-to-creatinine Ratio Values Research Articles

Evaluation of the diagnostic accuracy of microalbuminuria in predicting mortality among elderly patients with sepsis

Background: Sepsis is a common cause of morbidity and mortality among geriatrics. Aims and Objectives: The objective of study was to find the clinicomicrobiological profile of elderly inpatients (≥60 years) with sepsis and to evaluate the diagnostic accuracy of urine albumin to creatinine ratio (ACR) or microalbuminuria in predicting mortality. Materials and Methods: A prospective observational study was conducted among 50 geriatric patients admitted with sepsis in the ward or intensive therapy unit under medicine department of a tertiary care center for a period of 1 year. Baseline clinicomicrobiological profile was noted. Urine ACR values were measured at admission, day 4, and day 7 and geriatrics were followed up for 28 days to see the outcome. Receiver operator characteristic curve analysis was performed to evaluate the area under the curve for microalbuminuria on the 3 days and to determine the optimum cut-off points to predict mortality. Results: The mortality rate within 28 days was 64%. Urine microalbuminuria on day 1, day 4, and day 7 of admission was significantly higher among the non-survivors compared to survivors (P≤0.001, P≤0.001, and P=0.006, respectively). Microalbuminuria levels (in mcg/mg) of 143.0, 60.05, and 42.6 on day 1, 4, and 7 of admission, respectively, can be used as the cut-off to predict the death of geriatric sepsis inpatients with overall diagnostic accuracy of 83.0%, 83.4% and 86.1%, respectively, sensitivity as 93.75%, 87.50%, and 100.0%, respectively, and specificity as 44.44%, 72.22%, and 72.22%, respectively. Conclusion: Microalbuminuria can be a potential biomarker to predict death among geriatric septic inpatients, which can further help in improving the treatment strategy.

Age- and Gender-Specific Diagnostic Value of the Albumin-to-Creatinine Ratio for the Early Screening of Chronic Kidney Disease Among Middle-Aged and Elderly Males in Southeast China.

To evaluate the potential diagnostic value of the albumin-to-creatinine ratio (ACR) in screening for early kidney injury in a physically examined population from Southeast China. A total of 13,250 candidates were selected. Urinary ACR values <30, 30-300, and >300 mg/g were utilized as positive cut-off points to denote normal proteinuria, microalbuminuria, and macroalbuminuria, respectively. Age, systolic blood pressure, diastolic blood pressure, body mass index, waistline, fasting blood glucose, glycated hemoglobin, triglycerides, and high-density lipoprotein cholesterol were significantly different among the three groups. eGFR was negatively correlated with the levels of sCr, BUN, and UA in the microalbuminuria and macroalbuminuria groups. Furthermore, there was a significant difference in CKD stage between the normal and abnormal urine ACR groups. Meanwhile, for the 20-40 years patients, the eGFR, sCr and BUN showed no significant difference between microalbuminuria group compared with the normal proteinuria group; in contrast, for the 41-60 years and >61 years patients, eGFR, sCr, BUN and UA were all markedly increase in microalbuminuria and macroalbuminuria group in comparison with the normal proteinuria group. Finally, for the 41-60 males, only eGFR significantly decreased in microalbuminuria group compared with the normal proteinuria group, while for the 41-60 females, only UA showed no significant difference between microalbuminuria group and normal proteinuria group. On the other hand, for the >61 males, eGFR, sCr and BUN all significantly changed between microalbuminuria group and normal proteinuria group, while for the >61 females, eGFR, sCr and BUN all showed no significant difference between microalbuminuria group and normal proteinuria group, as well as microalbuminuria group and macroalbuminuria group. We proposed using the urinary ACR for the screening of physically examined patients, especially among the elderly males. This approach would assist in the early diagnosis and treatment of renal damage.

Alpha-1 Acid Glycoprotein and Podocin mRNA as Novel Biomarkers for Early Glomerular Injury in Obese Children.

Introduction: Obesity, which is a serious problem in children, has a negative impact on many organs, including kidneys, and obesity-related glomerulopathy (ORG) is an increasingly common cause of ESKD (end-stage kidney disease) in adults. Early-detected and -treated glomerular lesions are reversible, so it is important to find a useful marker of early damage. The study aimed to evaluate the albumin-to-creatinine ratio (ACR), urinary alpha-1-acid glycoprotein (α1-AGP), and mRNA of podocyte-specific proteins as indicators of glomerular injury and their relationship with the degree of obesity and metabolic disorders. Materials and Methods: A total of 125 obese children and 33 healthy peers were enrolled. Patients were divided into two groups, depending on SDS BMI values. ACR, α1-AGP, mRNA expression of nephrin, synaptopodin, podocin, and C2AP protein in urine sediment were measured. Results: ACR values did not differ between groups and were within the normal range. α1-AGP and mRNA expression were significantly higher in obese children compared with controls. mRNA expression of the remaining podocyte proteins was similar in both groups. No significant differences concerning all examined parameters were found depending on the degree of obesity. There was a positive significant correlation between α1-AGP and ACR. Conclusions: Increased α1-AGP before the onset of albuminuria suggests its usefulness as a biomarker of early glomerular damage in obese children. An increased podocin mRNA expression also indicates podocyte damage and may be linked to ORG development. The lack of increase in expression of other podocyte proteins suggests that podocin mRNA may be a more specific and sensitive biomarker. The degree of obesity has no impact on the tested parameters, but further studies are needed to confirm it.

TCA Cycle and Fatty Acids Oxidation Reflect Early Cardiorenal Damage in Normoalbuminuric Subjects with Controlled Hypertension.

Moderately increased albuminuria, defined by an albumin to creatinine ratio (ACR) > 30 mg/g, is an indicator of subclinical organ damage associated with a higher risk of cardiovascular and renal disease. Normoalbuminuric subjects are considered at no cardiorenal risk in clinical practice, and molecular changes underlying early development are unclear. To decipher subjacent mechanisms, we stratified the normoalbuminuria condition. A total of 37 hypertensive patients under chronic renin–angiotensin system (RAS) suppression with ACR values in the normoalbuminuria range were included and classified as control (C) (ACR < 10 mg/g) and high-normal (HN) (ACR = 10–30 mg/g). Target metabolomic analysis was carried out by liquid chromatography and mass spectrometry to investigate the role of the cardiorenal risk urinary metabolites previously identified. Besides this, urinary free fatty acids (FFAs), fatty acid binding protein 1 (FABP1) and nephrin were analyzed by colorimetric and ELISA assays. A Mann–Whitney test was applied, ROC curves were calculated and Spearman correlation analysis was carried out. Nine metabolites showed significantly altered abundance in HN versus C, and urinary FFAs and FABP1 increased in HN group, pointing to dysregulation in the tricarboxylic acid cycle (TCA) cycle and fatty acids β-oxidation. We showed here how cardiorenal metabolites associate with albuminuria, already in the normoalbuminuric range, evidencing early renal damage at a tubular level and suggesting increased β-oxidation to potentially counteract fatty acids overload in the HN range.

MO156THE ‘WITHIN-DAY’ VARIABILITY OF ALBUMINURIA INFLUENCES THE MONITORING OF NEPHROPROTECTIVE TREATMENT EFFECT

Abstract Background and Aims Measurement of urine proteins, mainly through the 24-hour excretion or the albumin-to-creatinine ratio (ACR) has become crucial in current clinical practice in Nephrology. Besides being a biomarker of injury, albuminuria also exerts direct pro-inflammatory and pro-fibrotic effects on renal tubules. Hence, a large number of intervention studies have been aimed at lowering albuminuria levels in patients with Chronic Kidney Disease (CKD). However, albuminuria is a measure characterized by a random variability that has been evaluated in several mechanistic and experimental studies and may be influenced by several factors, such as posture, exercise and dietary factors. The aim of the present study was to evaluate the within-day variability, specifically in a cohort of CKD outpatients who were on Renin-Angiotensin-Aldosterone-System inhibitors (RAASi) therapy. Method We enrolled consecutive CKD patients referred to the Nephrology Unit at Magna Graecia University Hospital of Catanzaro between January 1st and March 30th 2020. Inclusion criteria were: age &amp;gt; 18 years, diagnosis of CKD from any cause, presence of albuminuria in the range 150-3500 mg/g at screening. Patients already treated with RAASi, patients with active malignancy/signs of glomerulonephritis requiring immunosuppressive therapies, were excluded. At screening visit, patients with increased albuminuria were started with an Angiotensin Converting Enzyme inhibitor (ACEi) or an Angiotensin II Receptor Blocker (ARB). A second ambulatory visit was scheduled 1 month after start of RAASi therapy. During this visit, patients were asked to stay in the Renal Unit for 12 hours. They collected urine void for ACR, protein-to-creatinine ratio (PCR) and urine creatinine (Ucreat) assessment at 8am,1pm and 6pm. For each patient, comparisons between ACR, PCR and Ucreat were assessed by Kruskal-Wallis test and Friedman post-hoc, using the Benjamini-Hochberg as adjustment method. Coefficients of variation (CV,standard deviation/mean) were also computed. Results Final analysis included 43 patients (46.5% of males). Mean age was 59.6±16.7 years and median eGFR 41 [21-74] mL/min/1.73m2. A high cardiovascular (CV) risk profile was testified by the prevalence of type 2 diabetes (30.2%) and previous CV disease (34.8%). When patient characteristics were compared across ACR categories (&amp;lt;30, 30-300, &amp;gt;300 mg/g), systolic blood pressure was increased (p=0.020) and mean age decreased from 68.0 to 54.8 years on average (p=0.038). ACR values collected were 189 [38-759], 252 [51-1685] and 229 [56-1185] mg/g at 8am, 1pm and 6pm, respectively, with a CV of 24.6% (95%CI 12.4-39.1). 8am ACR was significantly different from 1pm ACR (p&amp;lt;0.001) and from 6pm ACR (p&amp;lt;0.001). 1 pm ACR was significantly different from 6pm ACR (p=0.002). Median PCR were 335 [115-932], 429 [146-1811] and 447 [151-1465] mg/g respectively at 8am, 1pm and 6pm, with CV being 17.8% (95%CI 9.0-26.6). 8am PCR differed significantly from 1pm and 6pm PCR (p&amp;lt;0.001 for both), while 1pm ACR was lower than 6pm ACR (p&amp;lt;0.001). Ucreat was 66 [53-103], 63 [47-96] and 69 [50-90] mg/dL respectively at 8am, 1pm and 6pm with no significant variation trend. Individual within-day ACR and PCR trends are depicted in the Figure . Conclusion The present analysis showed a significant individual within-day variability of albuminuria, measured as both ACR and PCR, suggesting that another parameter, in addition to those already known, may be responsible for the day-by-day albuminuria variation. Moreover, the absence of variability in Ucreat, namely the denominator of the ACR/PCR formula, suggests that the true variation is likely dependent on the urine protein values. Thus, albuminuria reduction in response to RAASi treatment should be carefully evaluated by measuring ACR/PCR preferentially at a similar time of the day for each patient. This would allow to avoid under- or overestimation of the actual treatment effect.

SGLT2 Inhibition in Patients With Type 2 Diabetes Mellitus Post-Nephrectomy: A Single-Center Case Series

Background:Nephrectomy is the mainstay of treatment for many kidney cancers, but has been correlated with increased incidence of acute kidney injury (AKI) and chronic kidney disease (CKD). Recently, sodium-glucose cotransporter-2 (SGLT2) inhibition has been shown to decrease the incidence of end-stage kidney disease and death in people with type 2 diabetes mellitus (T2D). However, at present, there has been no description of the use of SGLT2 inhibition in patients with T2D and solitary kidney despite the high risk of CKD progression.Objective:To characterize the use of SGLT2 inhibition and kidney function in a series of patients with T2D with prior nephrectomy for renal cell carcinoma (RCC).Design:Retrospective case series.Setting:University hospital outpatient onco-nephrology clinic.Patients:Patients post-nephrectomy for RCC with T2D who were prescribed an SGLT2 inhibitor.Measurements:Serum creatinine, albumin to creatinine ratio (ACR), HgA1c, and blood pressure measurements.Methods:Patients post-nephrectomy with incident use of SGLT2 inhibitor were identified from an existing registry of patients followed in the Onco-Nephrology Clinic at our institution from May 2019 to March 2021. Demographics, medication use, time since nephrectomy, cancer diagnosis, serum creatinine, ACR measurements, and blood pressure measurements were extracted from electronic medical records.Results:Five patients were identified who had initiated SGLT2 inhibition post-nephrectomy. All patients were male, had T2D, and a prior history of hypertension. Renal cell carcinoma was the clinical indication for nephrectomy in all patients. None of patients were prescribed diuretics, and all were receiving renin-angiotensin system (RAS) inhibition therapies. The time from nephrectomy to SGLT2 inhibitor initiation ranged from 5 to 74 months. Baseline mean estimated glomerular filtration rate (eGFR) values were 49 mL/min/1.73 m2 (95% confidence interval [CI]: 31.5-66.5), and mean ACRs were 8.7 mg/mmol (95% CI: 0.6-16.9). After 6 months of SGLT2 inhibition, the mean eGFR and ACR values were 58 mL/min/1.73 m2 (95% CI: 29.7-86.2) and 23.8 mg/mmol (95% CI: 0-60), respectively. After 16 to 18 months of follow-up (4 patients), the mean eGFR was 56 mL/min/1.73 m2 (95% CI: 37.3-74.7), and mean ACR was 10.5 (95% CI: 0-30.5), similar to baseline values before SGTL2i therapy initiation. At baseline, mean systolic blood pressure was 128 mm Hg (95% CI: 118.3-140.9) and remained similar after 12 months of treatment (mean 131 mm Hg [95% CI: 112.3-149.7]). There were no adverse events related to AKI, electrolyte disturbances, ketoacidosis, or genitourinary infections during the 18-month follow-up period.Limitations:Small sample size, lack of a comparison group, and the variable timing of clinical data collection, including eGFR levels following initiation of SGLT2 inhibition.Conclusions:SGLT2 inhibition is becoming a standard component of nephrology care to reduce kidney function decline, cardiovascular risk, and mortality. To our knowledge, our report is the first to provide longitudinal data on SGLT2 inhibitor usage in patients with T2D and solitary kidneys post-nephrectomy. Larger prospective studies are needed to determine the efficacy and safety of SGLT2 inhibition strategies for kidney protection in patients post-nephrectomy.

Albuminuria rather than glomerular filtration rate is associated with vascular endothelial function in patients with type 2 diabetes

AimsAlbuminuria and reduced glomerular filtration rate (GFR) are manifestations of diabetic kidney disease and are both shown to be associated with cardiovascular outcomes. However, the differential association of albuminuria and reduced GFR with endothelial dysfunction, an early feature of atherosclerotic vascular damage, remains unclear. In this study, we investigated the association between albuminuria or estimated GFR (eGFR) and flow-mediated dilatation (FMD), a marker of endothelial function, in patients with type 2 diabetes. MethodsThis study included 633 patients with type 2 diabetes. The FMD of the brachial artery was measured by ultrasonography. Albuminuria was evaluated by urinary albumin-to-creatinine ratio (ACR). ResultsThe mean FMD and eGFR, and the median value of ACR were 6.7%, 66.5 mL/min/1.73m2 and 12.5 mg/g creatinine, respectively. Impaired FMD was found in patients with advanced stages of chronic kidney disease based on both GFR and albuminuria categories. Multivariate analysis after adjusting for potential confounders revealed that ACR, but not eGFR, was significantly and inversely associated with FMD. ConclusionsAlbuminuria is associated with FMD, independently of traditional cardiovascular risk factors in patients with type 2 diabetes. This study suggests a close relationship between albuminuria, rather than reduced GFR, and endothelial dysfunction in type 2 diabetes.

High ACR level is a strong risk factor for renal tubular impairment in patients with type 2 diabetes: A longitudinal observational study

BackgroundSeveral studies have indicated that high albuminuria is associated with renal function decline. However, the relationship between the urinary albumin-to-creatinine ratio (ACR) and risk of developing tubular injury remains unclear. Our aim was to investigate the association of ACR with the risk of developing tubular impairment in patients with type 2 diabetes. MethodsThis longitudinal observational study compared baseline with follow-up data in 183 patients with type 2 diabetes. ACR, urinary alpha-1-microglobulin-to-creatinine ratio (A1MCR) and estimated glomerular filtration rate (eGFR) were used to evaluate albuminuira, tubular injury and glomerular filtration function, respectively. ResultsLevels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and A1MCR were significantly different at the two-year follow-up compared with baseline levels. Among patients both with baseline ACR above and below 30 mg/g, the percentage with A1MCR > 15 mg/g clearly increased after follow-up (P < 0.05). The risk of A1MCR rising from normal ranges to >15 mg/g over the follow-up increased with increasing baseline ACR values lower baseline eGFR. Among the patients with baseline ACR > 63.10 mg/g, all showed increased A1MCR values at follow-up compared with baseline. In the multivariate regression analysis, the patients with baseline ACR > 63.10 mg/g had a strong risk of A1MCR rising from normal to >15 mg/g (odds ratio (OR) = 11.12, P = 0.001) over the follow-up, while the males had a 2.89-fold risk of A1MCR increasing from normal to >15 mg/g compared with females. ConclusionBaseline ACR level is related to increased risk of developing renal tubular injury; in particular, this association is much stronger in patients with type 2 diabetes and baseline ACR > 63.10 mg/g.

Higher 24-hour urine Na/K and albumin-to-creatinine ratio are subclinical organ damage markers in hypertensive patients from Blida (Algeria)

The aim of this study was to evaluate the relationship between ACR (albumin-to-creatinine ratio) and markers of TOD (target organ damage) in treated hypertensive patients. We enrolled 859 consecutive essential hypertensives (mean age 55 ± 10 years, 444 females) without known cardiovascular disease (CVD). LVMI was assessed by echocardiography by using the Devereux formula. eGFR was calculated by the MDRD equation. In a 24-hour urine collection, sodium/potassium ratio and ACR were measured. Valid 24-h ambulatory BP monitoring were analyzed. Participants were grouped in 4 groups: normotensives, isolated daytime hypertensives (IDHT), isolated nocturnal hypertensives (INHT), and both-hypertensives having both daytime and nocturnal hypertension. The 24-hour urine sodium (24HUNa) was 151.7 ± 71.4, 158.4 ± 69.3, 168.7 ± 68.8 and 177.1 ± 70.7 mmol/24 hour, respectively. The 24-hour urine potassium (24HUK) was 52.4 ± 17.8, 54.1 ± 16.2, 59.8 ± 20.7 and 62.1 ± 20.4 mmol/24 hour and the 24-hour urine sodium/potassium ratio (24HUNa/24HUK) were 3.1 ± 2.2, 3.3 ± 1.5, 3.2 ± 2.7 and 3.0 ± 2.3 respectively. Compared to NT group, INHT had higher 24HUNa ( P = 0.01), and both-HT had higher 24HUNa and 24HUNa/24HUK ( P < 0.01 and 0.01, respectively). There was no difference in 24HUNa, 24HUNK and 24HUNa/24HUK between INHT and both-HT. In multivariate analysis controlled with age, gender, body mass index, estimated glomerular filtration rate, INHT showed significantly higher 24HUNa/24HUK than NT ( P < 0.02). ACR exhibited significant association with LVMI (r = 0.312, P = 0.01) and eGFR ( r = –0.122, P = 0.01). In additional analysis, ACR was associated with TOD and decreased renal function (eGFR < 60 ml/min). Specifically, ACR exhibited a significant association with the number of TOD and this association was independent of age and gender ( P < 0.01). The results of present study suggest that high ratio of sodium/potassium may be a risk of isolated nocturnal hypertension and both-hypertension. Our findings support the close relationship between ACR and TOD in hypertension, as well as, the predictive value of ACR as a predictive of TOD.

The glycosylated haemoglobin A1c and albuminuria in patients with type 2 diabetes in the Republic of Srpska: A cross sectional study

Background/Aim. Glycosylated haemoglobin (HbA1c) is currently the gold standard for glucose monitoring in the patients with diabetes. The aim of the present study was to examine the level of success in implementing international guideline targets with regard to glycaemic control in the patients with type 2 diabetes in the Republic of Srpska. This study also aimed to determine the association of albuminuria with the glycaemic control and lipid levels in this patient population. Methods. The participating diabetic patients were those registered in the project titled ??Estimation of the quality of glycoregulation and presence of vascular complications in the persons with diabetes in the Republic of Srpska.? The study was conducted as a cross-sectional study including 1037 patients. HbA1c was determined by a turbidimetric inhibition immunoassay used Roche Diagnostics. Total cholesterol, triglycerides, LDL-C, and HDL-C were determined by reagents from Roche Diagnostics (Roche Diagnostics, Mannheim, Germany) as well as albumin and creatinine in the urine. Results. Mean value for HbA1c was 7.35 ? 1.61% (57 ? 18 mmol/moL). The 49.46% of all participants achieved target values of HbA1c (&lt; 7% or 53 mmol/moL) and 40.30% had albumin to creatinine ratio (ACR) &lt; 30 mg/g. When the patients were divided according to HbA1c (with HbA1c &lt; 7%, 519 patients, and HbA1c ? 7.0%, 510 patients) the ACR values were different between these groups (39.00 vs. 79.50, p &lt; 0.001). We found no significant difference with respect to lipid status between the groups. Conclusion. The patients with type 2 diabetes in the Republic of Srpska, in a large percentage, did not meet targets for glycaemic control. Improvements are necessary in the treatment and maintenance of this disease process to ensure achievement of goals in management of diabetes, which in turn would decrease longstanding complications of type 2 diabetes.

Normal-to-mildly increased albuminuria predicts the risk for diabetic retinopathy in patients with type 2 diabetes

Albuminuria is closely associated with diabetic retinopathy (DR), but the precise role of the albumin-to-creatinine ratio (ACR) in screening for DR remains to be determined. This study aimed to investigate an ACR threshold for predicting DR in patients with type 2 diabetes. A cross-sectional study was conducted on 1,102 type 2 diabetes patients, aged ≥30 years and recruited from the Korea National Health and Nutrition Examination Survey, 2010–2011. Participants were grouped by stage of DR: mild-to-moderate nonproliferative DR (NPDR), severe NPDR, and proliferative diabetic retinopathy (PDR). An early morning spot urine sample was obtained for ACR measurement. ROC curve analysis revealed that the optimal cut-off value of ACR for predicting DR was 2.26 mg/mmol (20 μg/mg). The prevalence of ACR ≥ 2.26 mg/mmol tended to increase with severity of DR. The risk for DR in patients with ACR ≥ 2.26 mg/mmol was higher than in those with ACR < 2.26 mg/mmol. The risk for severe NPDR and PDR also increased at ACR ≥ 2.26 mg/mmol. Normal-to-mildly increased albuminuria (an ACR of 2.26 mg/mmol) may predict the risk for DR development and progression in patients with type 2 diabetes.

Urinary albumin excretion and chronic kidney disease in children with vesicoureteral reflux

Albuminuria is a potential biomarker of chronic kidney disease (CKD) in various glomerular diseases. Vesicoureteral reflux (VUR) often progresses to CKD, and study is required of use of albuminuria as a biomarker for this condition. The aim of this study was to evaluate the association between albuminuria and glomerular filtration rate (GFR) or filtration fraction (FF) in children with VUR. In this retrospective study, renal parameters of 141 children with VUR were investigated, using inulin clearance, FF, and albuminuria. The association between urinary albumin to creatinine ratio (ACR), GFR, and FF was analyzed in a continuous manner by calculating the β coefficient, and also in a binary manner by calculating the OR. Using both continuous and binary analyses, ACR values were negatively and significantly associated to GFR values in patients with low, normal, or high FF values (Table). It was also positively and significantly associated with FF values in patients with low, normal or high GFR values (Table). No association was found between ACR and gender, VUR stages or laterality, number of urinary tract infection, presence of a single functional kidney, history of reflux surgery, or renal scars or hypertension. ACR is associated with CKD in patients with VUR. In addition, increased urinary albumin excretion cannot be completely and solely explained by decreased GFR and/or increased FF values. The two main limitations of this study are the crude assessment of renal scarring, which prevented finer analysis between albuminuria and renal scarring surface area, and that the study cohort may not be representative of the true VUR population. This study shows that albuminuria is associated with decreased renal function in patients with VUR and that it could be used to monitor renal function in this condition.

Single spot albumin to creatinine ratio: A simple marker of long-term prognosis in non-ST segment elevation acute coronary syndromes.

Microalbuminuria is a known risk factor for cardiovascular morbidity and mortality suggesting that it should be a marker of endothelial dysfunction. Albumin to creatinine ratio (ACR) is an available and rapid test for microalbuminuria determination, with a high correlation with the 24-h urine collection method. There is no prospective study that evaluates the prognostic value of ACR in patients with non ST-segment elevation acute coronary syndromes (NSTE-ACS). The purpose of our study was to detect the long-term prognostic value of ACR in patients with NSTE-ACS. Albumin to creatinine ratio was estimated in 700 patients with NSTE-ACS at admission. Median follow-up time was 18 months. The best cutoff point of ACR for death or acute myocardial infarction was 20 mg/g. Twenty-two percent of patients had elevated ACR. By multivariable Cox regression analysis, ACR was an independent predictor of the clinical endpoint: odds ratio 5.8 (95% confidence interval [CI] 2-16), log-rank 2 p < 0.0001 in a model including age > 65 years, female gender, diabetes mellitus, creatinine clearance, glucose levels at admission, elevated cardiac markers (troponin T/CK-MB) and ST segment depression. The addition of ACR significantly improved GRACE score C-statistics from 0.69 (95% CI 0.59-0.83) to 0.77 (95% CI 0.65-0.88), SE 0.04, 2 p = 0.03, with a good calibration with both models. Albumin to creatinine ratio is an independent and accessible predictor of long-term adverse outcomes in NSTE-ACS, providing additional value for risk stratification.

Consecutive first-morning urine samples to measure change in the albumin-to-creatinine ratio: a pilot study of a home urine collection protocol.

BackgroundMultiple first-morning urine samples are recommended for measuring the urine albumin-to-creatinine ratio (ACR); however, this can be challenging in community-based research.MethodsThe objectives of the study are to pilot-test a home urine collection protocol and examine how the average and variance of ACR varied with the number of urine collections and time to laboratory analysis. This is a prospective observational pilot study. This study was conducted in London, Ontario, Canada at the London Health Sciences Centre (2012–2013). The patients were adults with chronic kidney disease (mean estimated glomerular filtration rate, 36 mL/min/1.73 m2). Participants collected a first-morning 20-mL urine sample on three consecutive days. This process was repeated after 3 months. Samples were picked up by hospital courier and analyzed for ACR on the same day; additional aliquots were analyzed after a delay of 24–48 h (stored at 4 °C) and 3–9 months (stored at –80 °C). The geometric mean of the percentage change in ACR between baseline and 3 months was calculated and compared between single samples and the average of two vs. three consecutive samples.ResultsOf 31 patients enrolled, 26 (83.9 %) submitted all six urine samples. The geometric mean of ACR for three consecutive samples at baseline was 87, 83, and 80 mg/mmol, and the corresponding percentage increase from baseline to 3 months was 15 % (95 % confidence interval (CI), −9 to 46 %), 33 % (95 % CI, 10 to 59 %), and 22 % (95 % CI, −6 to 57 %). Compared with single urine collections at baseline and follow-up, averaging ACR values from two consecutive first-morning urine samples improved the sample variance and reduced the required sample size to detect a given treatment effect by approximately 30 %. No further gain in statistical efficiency was achieved with three urine samples. Results were similar when the laboratory analysis was delayed by 24–48 h, but a delay of 3–9 months resulted in systematic overestimation of the ACR. Our study’s generalizability is limited by its small sample size and reliance on a clinic-based population from a single urban center.ConclusionsWe successfully used a home urine collection protocol to obtain multiple first-morning urine samples in patients with chronic kidney disease. Statistical efficiency was improved by averaging ACR values from two consecutive first-morning urine samples at baseline and follow-up.

Normal Range Albuminuria and Metabolic Syndrome in South Korea: The 2011–2012 Korean National Health and Nutrition Examination Survey

BackgroundIt is well-known that there is a close relationship between metabolic syndrome (MetS) and microalbuminuria. However, some recent studies have found that even normal range albuminuria was associated with MetS and cardiometabolic risk factors. The purpose of this study is to analyze the relationship between MetS and normal range albuminuria and to calculate the cutoff value for albuminuria that correlates with MetS in the representative fraction of Korean population.MethodsData were obtained from the 2011–2012 Korea National Health and Nutrition Examination Survey and included 9,650 subjects aged ≥19 years. We measured metabolic parameters: fasting blood glucose, waist circumference, blood pressure, and lipids, and albumin-to-creatinine ratio (ACR). The optimal ACR cutoff points for MetS were examined by the receiver operating characteristic curve. Multivariate logistic regression was used to obtain the prevalence of MetS and its components according to the ACR levels.ResultsThe first cutoff value of ACR were 4.8 mg/g for subjects with ≥3 components of MetS. There was a graded association between ACR and prevalence of MetS and its components. If ACR was <4 mg/g, there was no significant increase in the prevalence of MetS or its components. From the ACR level of 4–5 mg/g, the prevalence of MetS significantly increased after adjusting for age, sex, body mass index, smoking, alcohol intake, exercise, and medications for diabetes mellitus and hypertension (odds ratio; 95% confidence intervals = 1.416; 1.041–1.926).ConclusionsAlbuminuria within the normal range (around 5 mg/g) was associated with prevalence of MetS in the Korean population.

The Shiga Microalbuminuria Reduction Trial (SMART) Group. Reduction of Microalbuminuria in Patients With Type 2 Diabetes: The Shiga Microalbuminuria Reduction Trial (SMART). Diabetes Care 2007;30:1581–1583. DOI: 10.2337/dc06-2493. Erratum appears in Diabetes Care 2013;36:4172. DOI: 10.2337/dc13-er12

Based on the review and recommendation of the American Diabetes Association's Subcommittee on Ethical Scientific Publications (ESP), Diabetes Care formally retracts the above-cited article. For reasons described below, the published data are considered to be unreliable. According to an investigation and analysis of the data conducted by Shiga University of Medical Science (report received 25 November 2013), 10.1% of the albumin-to-creatinine ratio (ACR) data reported in the article did not match original patient records. In the valsartan and amlodipine groups, respectively, 12.5% and 8.1% of the ACR data reported in the article differed from patient records. Close examination of these differences showed that ACR values reported for the valsartan group were smaller, and those for the amlodipine group were larger, than values reported in patient records; these differences "worked to the advantage of valsartan." The investigative panel of Shiga University of Medical Science concluded that the above-cited article is "inappropriate for [a] scientific paper."

English

INTRODUCTION:Diabetic nephropathy is the most common cause of End Stage Renal Disease (ESRD). The earliest clinical evidence of nephropathy is microalbuminuria. The commonly used investigations to diagnose microalbuminuria include 24 hours urinary Albumin Excretion Rate (AER), Albumin to Creatinine ratio (ACR) and spot microalbuminuria. These latter two methods have been found to be convenient, cost effective and efficient in screening patients of microalbuminuria when compared with 24 hour collections.AIM OF STUDY: The present study was conducted to know whether ACR or spot microalbuminuria alone can predict and quantify microalbuminuria in patients with Diabetic Nephropathy.METHODOLOGY:100 known patients of type II DM were enrolled for the study. 24 hour urinary sample was taken to quantify albuminuria and spot urine sample was taken for ACR and microalbuminuria. The results obtained by ACR and spot microalbuminuria were compared with the gold standard 24 hours urinary protein measurement.RESULTS:Sensitivity and specificity for predicting true microalbuminuria were found to be 91% and 75% respectively for ACR. Its positive predictive value was 57% and negative predictive value was 90%. Sensitivity and specificity were found to be 92% and 82% for spot microalbuminuria with positive predictive value of 40% and negative predictive value of 95%.CONCLUSION:The low specificity and low positive predictive value of ACR and spot microalbumin does not support their use for quantifying urinary albumin excretion and it was concluded that these methods alone cannot be relied upon for quantification of albuminuria. However the high sensitivity and negative predictive value of the tests suggests that these are good routine outdoor screening tests for finding out those patients who should undergo quantification by 24 hours urine albumin excretion.

Microalbuminuria can predict the development of acute kidney injury in critically ill septic patients

Microalbuminuria (MA) has long been associated with development of chronic kidney diseases in diabetic or hypertensive patients. However, its value in predicting acute kidney injury (AKI) in an intensive care unit (ICU) setting has never been reported. This study aimed to investigate the link between MA and AKI. Septic patients without AKI on entry to the ICU were enrolled from October 2010 to December 2011 in an 18-bed ICU. Urinary albumin to creatinine ratio (ACR) was measured in the morning on day 2. Patients were then followed up for the development of AKI, ICU length of stay (LOS) and hospital mortality, and the associations of those with initial ACR were tested. Diagnostic performance of ACR in predicting AKI was evaluated using receiver operating characteristic curves. A total of 84 septic patients were enrolled during the study period, of whom 36 developed AKI and 48 did not. ACR on ICU entry was an independent predictor of AKI (odds ratio [OR] = 1.02; p<0.01). The area under the curve of ACR in predicting AKI was 0.86 (95% confidence interval [95% CI], 0.77-0.94), with a sensitivity and specificity of 91.7% and 79.2%, respectively, at a cutoff of 143 mg/g. ACR was significantly higher in nonsurvivors than in survivors (198 vs. 133 mg/g; p = 0.02). In a linear regression model, ACR values significantly correlated to ICU length of stay (LOS = 0.02 × ACR + 8.19; 95% CI for the coefficient: 0.007-0.033; p = 0.002). ACR obtained on entry to ICU was highly predictive of AKI, and was also associated with mortality rate and ICU length of stay.

Racial differences in albuminuria, kidney function, and risk of stroke

The objective of this study was to examine the joint associations of estimated glomerular filtration rate (eGFR) and urinary albumin excretion with incident stroke in a large national cohort study. Associations of urinary albumin to creatinine ratio (ACR) and eGFR with incident stroke were examined in 25,310 participants of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a prospective study of black and white US adults ≥45 years of age. A total of 548 incident strokes were observed over a median of 4.7 years of follow-up. Higher ACR values were associated with lower stroke-free survival in both black and white participants. Among black participants, as compared to an ACR <10 mg/g, the hazard ratios of stroke associated with an ACR of 10-29.99, 30-300, and >300 mg/g were 1.41 (95% confidence interval [CI] 1.01-1.98), 2.10 (95% CI 1.48-2.99), and 2.70 (95% CI 1.58-4.61), respectively, in analyses adjusted for traditional stroke risk factors and eGFR. In contrast, the hazard ratios among white subjects were only modestly elevated and not statistically significant after adjustment for established stroke risk factors. eGFR <60 mL/min/1.73 m(2) was not associated with incident stroke in black or white participants after adjustment for established stroke risk factors. Higher ACR was independently associated with higher risk of stroke in black but not white participants from a national cohort. Elucidating the reasons for these findings may uncover novel mechanisms for persistent racial disparities in stroke.

Relation of Impaired Coronary Microcirculation to Increased Urine Albumin Excretion in Patients With Systemic Hypertension and No Epicardial Coronary Arterial Narrowing

Coronary flow reserve (CFR) is impaired and urinary albumin excretion is increased in patients with essential hypertension. Our aim was to investigate the associations between CFR and cardiac and renal damage in hypertensives. For this purpose we studied 37 never-treated hypertensives (57.9 years old, 16 men) without chest pain but with a positive ischemia stress test result and normal coronary arteries on coronary angiogram. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego) in the left anterior descending artery in response to bolus intracoronary administration of adenosine (60 μg) as the ratio of hyperemic to basal average peak velocity of the distal vessel. All participants underwent complete echocardiographic study including left ventricular diastolic function evaluation by tissue Doppler imaging (peak early diastolic velocity/peak atrial systolic velocity) and determination of the albumin-to-creatinine ratio (ACR). Hypertensives with low CFR (<2.5, n = 22) compared to those with high CFR (n = 15) exhibited a larger left ventricular mass index by 10.9 g/m(2) (p = 0.045) and ACR values by 10 mg/g (p <0.001). CFR was negatively correlated with logACR (r = -0.511, p = 0.001). LogACR (beta -0.792, p <0.001), male gender (beta 0.313, p = 0.005), left ventricular mass index (beta -0.329, p = 0.007), and peak early diastolic velocity/peak atrial systolic velocity (beta 0.443, p <0.001) were the only independent predictors of CFR in linear regression analysis (adjusted R(2) = 0.672). In conclusion, never-treated asymptomatic hypertensives who exhibit impaired CFR and angiographically normal epicardial arteries are characterized by intrarenal vascular damage as reflected by increased ACR. These findings suggest a plausible role of ACR estimation in the identification of hypertensive subjects with early coronary microvascular dysfunction.