Modified Cut-Off Value of the Urine Protein-To-Creatinine Ratio Is Helpful for Identifying Patients at High Risk for Chronic Kidney Disease: Validation of the Revised Japanese Guideline.

Chronic kidney disease (CKD) is a global public health issue, and strategies for its early detection and intervention are imperative. The latest Japanese CKD guideline recommends that patients without diabetes should be classified using the urine protein-to-creatinine ratio (PCR) instead of the urine albumin-to-creatinine ratio (ACR); however, no validation studies are available. This study aimed to validate the PCR-based CKD risk classification compared with the ACR-based classification and to explore more accurate classification methods. We analyzed two previously reported datasets that included diabetic and/or cardiovascular patients who were classified into early CKD stages. In total, 860 patients (131 diabetic patients and 729 cardiovascular patients, including 193 diabetic patients) were enrolled. We assessed the CKD risk classification of each patient according to the estimated glomerular filtration rate and the ACR-based or PCR-based classification. The use of the cut-off value recommended in the current guideline (PCR 0.15 g/g creatinine) resulted in risk misclassification rates of 26.0% and 16.6% for the two datasets. The misclassification was primarily caused by underestimation. Moderate to substantial agreement between each classification was achieved: Cohen's kappa, 0.56 (95% confidence interval, 0.45-0.69) and 0.72 (0.67-0.76) in each dataset, respectively. To improve the accuracy, we tested various candidate PCR cut-off values, showing that a PCR cut-off value of 0.08-0.10 g/g creatinine resulted in improvement in the misclassification rates and kappa values. Modification of the PCR cut-off value would improve its efficacy to identify high-risk populations who will benefit from early intervention.

Establishment of a method to detect microalbuminuria by measuring the total urinary protein-to-creatinine ratio in diabetic patients.

Diabetes and chronic kidney disease (CKD) which are risk facters of cardiovascular disease, are increasing global public health problems. Microalbuminuria is an early sign of progressive cardiovascular and renal disease in individuals with or without diabetes. Screening for microalbuminuria and early treatment are recommended for patients with increased cardiovascular and renal risk factors. However, the procedure used to measure urinary albumin is expensive. Alternatively, the measurement of total urinary protein is simple and inexpensive. Thus, we aimed to establish a method that could predict the presence of microalbuminuria by measuring the total protein-to-creatinine ratio. Spot urine samples were obtained from 150 patients with diabetes mellitus, and the total protein-to-creatinine ratio and the albumin-to-creatinine ratio (ACR) were measured. There was a significant positive correlation between the protein-to-creatinine ratio and the ACR (r = 0.95). The presence of albuminuria (both micro- and macroalbuminuria) could be predicted from the value of the protein-to-creatinine ratio in more than 90% of patients. A receiver-operating characteristic curve analysis revealed that the protein-to-creatinine ratio had a sensitivity and a specificity of 90.8% and 91.9%, respectively, for the detection of albuminuria and a cutoff value of 0.091 g/g creatinine. These results suggest that screening for microalbuminuria can be replaced by the detection of the protein-to-creatinine ratio, which may be cost-effective for patients with cardiovascular risks as well as for the general population.

Comparison of cardiovascular disease risk associated with 3 lipid measures in Japanese adults.

BACKGROUND: To assess dyslipidemia, measurement of low-density lipoprotein cholesterol via either Friedewald equation (LDL-F) or direct assay (LDL-D), and non-high-density lipoprotein cholesterol (non-HDL-C) are recommended with some guidelines showing preference to direct over calculated measurements. However, direct comparisons of their respective associations with cardiovascular disease (CVD) risk are currently unavailable. OBJECTIVE: In this study, we evaluated the clinical effectiveness of LDL-F and non-HDL-C vs LDL-D and their associations with CVD. METHODS: This retrospective cohort study comprised apparently healthy Japanese individuals who underwent an annual health check-up between 2005 and 2007 and completed a 5-year follow-up visit. The incidence of CVD, including coronary and cerebrovascular diseases, during a 5-year follow-up period was evaluated using multivariate logistic regression. RESULTS: At baseline, 26,739 participants (mean age, 47 years; 49.0% men) were enrolled, and 292 (1.09%) incidents of CVD were identified at follow-up. Baseline LDL-F, LDL-D, and non-HDL-C were all significantly associated with CVD, although the effect appeared higher for LDL-F, particularly for coronary heart disease. Increased risks of CVD were observed for high LDL-F (≥130 mg/dL), despite being categorized into the lower LDL category based on LDL-D (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.19-2.87) and non-HDL-C (OR, 1.75; 95% CI, 1.22-2.52). Without high LDL-F, no CVD associations were found for high LDL-D (P = .62) or non-HDL-C (P = .93). CONCLUSION: Despite growing availability of direct assays and increasing evidence of non-HDL-C utility, the Friedewald equation may offer better clinical utility for CVD prevention, especially in the screening of apparently healthy individuals.