Interest of Clinitek Microalbumin in screening for microalbuminuria: results of a multicentre study in 302 diabetic patients.
ABSTRACT A prospective survey was performed in 302 consecutive diabetic outpatients from 3 French diabetic centres to study the sensitivity and specificity of screening for microalbuminuria using Clinitek Microalbumin. Urinary samples with positive (at least one +) proteinuria, hematuria, leucocyturia, or nitrates using the Multistix strip were excluded from the study. Results obtained with Clinitek Microalbumin were compared to those observed with the reference method of the biological laboratory of the centre on the same urinary sample. A positive result was defined as an albumin-to-creatinine ratio > or =30 mg/g. Results were described in terms of sensitivity, specificity, positive and negative predictive values and likelihood ratio. Agreement rates were compared with the Kappa test. In the study population, 48 patients (17%) had a positive microalbuminuria with reference assay. However, different rates were found in each site (25%, 11%, and 15%, respectively, p<0.001). Using the Clinitek Microalbumin, a positive result was found among 86 patients (29%), (39%, 26%, and 23%, respectively). A good agreement was observed in the population as a whole (81%, K=0.47 +/- 0.06) and in each site (77%, 81%, 84%, respectively). Sensitivity was 79% (82%, 80%, 75%), specificity 81% (76%, 81%, 85%), positive predictive value 46% (53%, 35%, 46%), negative predictive value 95% (93%, 97%, 95%), and positive likelihood ratio 4.2 (3.4, 4.3, 5.0, respectively). Due to the excellent negative predictive value, these results suggest that Clinitek Microalbumin is a good screening test for microalbuminuria. Positive results should be confirmed using a reference assay.
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ABSTRACT: Treatment of hypertension is difficult in chronic kidney disease (CKD), and blood pressure goals remain controversial. The association between each blood pressure component and end-stage renal disease (ESRD) risk is less well known. We studied associations of systolic and diastolic blood pressure (SBP and DBP, respectively) and pulse pressure (PP) with ESRD risk among 16,129 Kidney Early Evaluation Program (KEEP) participants with an estimated glomerular filtration rate of 60 mL/min/1.73 m(2) using Cox proportional hazards. We estimated the prevalence and characteristics associated with uncontrolled hypertension (SBP ≥ 150 or DBP ≥ 90 mm Hg). The mean (SD) age of participants was 69 (12) years; 25% were black, 6% were Hispanic, and 43% had diabetes mellitus. Over 2.87 years, there were 320 ESRD events. Higher SBP was associated with higher ESRD risk, starting at SBP of 140 mm Hg or higher. After sex and age adjustment, compared with SBP lower than 130 mm Hg, hazard ratios (HRs) were 1.08 (95% CI, 0.74-1.59) for SBP of 130 to 139 mm Hg, 1.72 (95% CI, 1.21-2.45) for SBP of 140 to 149 mm Hg, and 3.36 (95% CI, 2.51-4.49) for SBP of 150 mm Hg or greater. After full adjustment, HRs for ESRD were 1.27 (95% CI, 0.88-1.83) for SBP of 140 to 149 mm Hg and 1.36 (95% CI, 1.02-1.85) for SBP of 150 mm Hg or higher. Persons with DBP of 90 mm Hg or higher were at higher risk for ESRD compared with persons with DBP of 60 to 74 mm Hg (HR, 1.81; 95% CI, 1.33-2.45). Higher PP was also associated with higher ESRD risk (HR, 1.44 [95% CI, 1.00-2.07] for PP ≥ 80 mm Hg compared with PP < 50 mm Hg). Adjustment for SBP attenuated this association. More than 33% of participants had uncontrolled hypertension (SBP ≥ 150 mm Hg or DBP ≥ 90 mm Hg), mostly due to isolated systolic hypertension (54%). In this large, diverse, community-based sample, we found that high SBP seemed to account for most of the risk of progression to ESRD. This risk started at SBP of 140 mm Hg rather than the currently recommended goal of less than 130 mm Hg, and it was highest among those with SBP of at least 150 mm Hg. Treatment strategies that preferentially lower SBP may be required to improve BP control in CKD.Archives of internal medicine 01/2012; 172(1):41-7. DOI:10.1001/archinternmed.2011.619 · 13.25 Impact Factor
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ABSTRACT: The concordance of microalbuminuria and diabetic retinopathy (DR) has been well reported in persons with type 1 diabetes; however, for type 2 diabetes, there is paucity of data especially from population-based studies. The aim of this study was to estimate the prevalence of albuminuria (micro - and macroalbuminuria) among persons with type 2 diabetes and determine its role as a risk factor for presence and severity of DR. A population-based cross sectional study was conducted in cohort of 1414 subjects with type 2 diabetes from Chennai metropolis. All the subjects underwent comprehensive eye examination including 45 degrees four-field stereoscopic digital photography. DR was clinically graded using Early Treatment Diabetic Retinopathy Study scales. A morning urine sample was tested for albuminuria. Subjects were considered to have microalbuminuria, if the urinary albumin excretion was between 30 and 300 mg/24 hours, and macroalbuminuria at more than 300 mg/24 hours. The statistical software used was SPSS for Windows, Chicago, IL. Student t-test for comparing continuous variables, and χ2 test, to compare proportions amongst groups were used. The prevalence of microalbuminuria in the study subjects was 15.9% (226/1414), and that of macroalbuminuria, 2.7% (38/1414). Individuals with macroalbuminuria in comparison to micro- or normoalbuminuria showed a greater prevalence of DR (60.5% vs. 31.0% vs. 14.1%, p < 0.001), and also a greater severity of the disease (60.9% vs. 21.4 vs. 9.9, p < 0.001). Every 6th individual in the population of type 2 diabetes is likely to have albuminuria. Subjects with microalbuminuria were around 2 times as likely to have DR as those without microalbuminuria, and this risk became almost 6 times in the presence of macroalbuminuria.Diabetology and Metabolic Syndrome 05/2011; 3(1):9. DOI:10.1186/1758-5996-3-9 · 2.50 Impact Factor
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ABSTRACT: Albuminuria is an important sign of chronic kidney disease and is detected routinely by measurement of urinary albumin-creatinine ratio (ACR). A Siemens CLINITEK test designed for use at the point of care is available that can semiquantitatively measure ACR. Diagnostic accuracy study evaluating a urinary ACR point-of-care test. The semiquantitative ACR test was evaluated at the point of care in a representative primary care population (those with or at increased risk of chronic kidney disease) of 642 patients under standard operational conditions and compared with the reference standard of ACR measurement in the clinical laboratory. The point-of-care CLINITEK semiquantitative ACR test. This test uses dye-binding and catalytic assays for albumin and creatinine, respectively, on a Microalbumin 9 strip, which is read by the CLINITEK Status Analyzer, and ACR is calculated automatically. Laboratory measurement of albumin and creatinine on an Abbott Architect analyzer by immunoturbidimetric and enzymatic assays, respectively, and calculation of ACR. The prevalence of albuminuria (laboratory ACR ≥30 mg/g) in the study population was 20.2%. Sensitivity and specificity of the point-of-care test for detecting albuminuria were 83.2% and 80.0%, respectively. Positive and negative predictive values were 51.2% and 95.0%, respectively; positive and negative likelihood ratios were 4.16 and 0.21, respectively. Twenty-three (3.6%) samples measured at the point of care were not analyzed in the central laboratory for a variety of reasons, including laboratory reception data entry errors. Our sensitivity calculation is accurate to an approximately 8% CI. The instrument-read reagent strip test was a poor rule-in test for albuminuria at the point of care, as evidenced by the low positive predictive value, but was a reasonable rule-out test. Observed sensitivity was lower than reported in earlier laboratory-based studies. This decreased diagnostic accuracy needs to be balanced against the potential advantages of a point-of-care testing approach.American Journal of Kidney Diseases 06/2012; 60(5):787-94. DOI:10.1053/j.ajkd.2012.05.009 · 5.76 Impact Factor