Gao C, et al. - Because intrarenal Aquaporin 5 (AQP5) is upregulated in patients with diabetic nephropathy, researchers ascertained if urinary AQP5 is independently correlated with estimated glomerular filtration rate (eGFR) decline in patients with type 2 diabetes and nephropathy. Baseline urine samples were measured for AQP5 using enzyme-linked immunosorbent assays from 997 patients with type 2 diabetes and nephropathy of the sulodexide macroalbuminuria trial. Patients with AQP5's highest tertile had significantly higher total cholesterol, lower baseline eGFR, and higher albuminuria levels compared with the lowest tertile. Investigators found that AQP5 was inversely associated with eGFR slope, and independent of clinical risk factors age, sex, race, and baseline systolic and diastolic blood pressure, hemoglobin A1c, total cholesterol, eGFR, and urine albumin-to-creatinine ratio. Moreover, AQP5 was significantly linked to fast eGFR decline. In patients with type 2 diabetes and nephropathy, baseline AQP5 is independently linked to the progression of eGFR decline.