Diagnostic efficacy of random albumin creatinine ratio for detection of micro and macro-albuminuria in type 2 diabetes mellitus

OBJECTIVES To compare a less cumbersome random albumin creatinine ratio (RACR) with 24-hour urinary albumin excretion (UAE) for detection of renal damage in patients with type 2 diabetes mellitus (T2DM). METHODS This retrospective study performed between March 2013 and June 2014 at the Department of Pathology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia included 122 patients (mean age 54 ± 15, 104 females and 18 males) with T2DM. Urine albumin levels of less than 30 mg/g was considered normal, from 30-300 mg/g considered as micro-albuminuria, and over 300 mg/g considered as macro-albuminuria. RESULTS Concordance between the 2 assays was observed in 114 (93.4%) samples. The sensitivity of RACR assay was 100%, specificity was 91.3% with a positive predictive value (PPV) of 95%, and a negative predictive value (NPV) of 100% in micro-albuminuria range. For macro-albuminuria, RACR had a sensitivity of 100%, specificity of 94.1% with PPV of 94% and NPV of 100%. Receiver operating characteristic (ROC) curves analysis cut-off values of 40 mg/g-300 mg/g for micro- and greater than 300 mg/g for macro-albuminuria revealed 100% sensitivity, 97.5% specificity, 95% PPV, and 100% NPV for micro-albuminuria, and 100% sensitivity, 94% specificity, 76% PPV, and 100% NPP for macro-albuminuria. The area under the curve for micro-albuminuria was 100% and 98.2% for macro-albuminuria. CONCLUSION Performance of RACR was comparable to 24 hour UAE assay particularly in excluding renal damage in T2DM.