Orit Erman1, Arie Erman2, Alina Vodonos3, Uzi Gafter2,4, David J van Dijk2,4. 1. Department of Internal Medicine A, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel. 2. Department of Nephrology and Hypertension, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel. 3. Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel. 4. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Abstract
BACKGROUND: Proteinuria and albuminuria are markers of kidney injury and function, serving as a screening test as well as a means of assessing the degree of kidney injury and risk for cardiovascular disease and death in both the diabetic and the non-diabetic general population. OBJECTIVES: To evaluate the association between proteinuria below 300 mg/24 hours and albuminuria, as well as a possible association with kidney function in patients with diabetes mellitus (DM). METHODS: The medical files of patients with type 1 and type 2 DM with proteinuria below 300 mg/24 hours at three different visits to the Diabetic Nephropathy Clinic were screened. This involved 245 patient files and 723 visits. The data collected included demographics; protein, albumin and creatinine levels in urine collections; blood biochemistry; and clinical and treatment data. RESULTS: The association between proteinuria and albuminuria is non-linear. However, proteinuria in the range of 162-300 mg/24 hours was found to be linearly and significantly correlated to albuminuria (P < 0.001, r = 0.58). Proteinuria cutoff, based on albuminuria cutoff of 30 mg/24 hours, was found to be 160.5 mg/24 hr. Body mass index (BMI) was the sole independent predictor of proteinuria above 160.5 mg/24 hr. Changes in albuminuria, but not proteinuria, were associated with changes in creatinine clearance. CONCLUSIONS: A new cutoff value of 160.5 mg/hr was set empirically, for the first time, for abnormal proteinuria in diabetic patients. It appears that proteinuria below 300 mg/24 hr is not sufficient as a sole prognostic factor for kidney failure.
BACKGROUND:Proteinuria and albuminuria are markers of kidney injury and function, serving as a screening test as well as a means of assessing the degree of kidney injury and risk for cardiovascular disease and death in both the diabetic and the non-diabetic general population. OBJECTIVES: To evaluate the association between proteinuria below 300 mg/24 hours and albuminuria, as well as a possible association with kidney function in patients with diabetes mellitus (DM). METHODS: The medical files of patients with type 1 and type 2 DM with proteinuria below 300 mg/24 hours at three different visits to the Diabetic Nephropathy Clinic were screened. This involved 245 patient files and 723 visits. The data collected included demographics; protein, albumin and creatinine levels in urine collections; blood biochemistry; and clinical and treatment data. RESULTS: The association between proteinuria and albuminuria is non-linear. However, proteinuria in the range of 162-300 mg/24 hours was found to be linearly and significantly correlated to albuminuria (P < 0.001, r = 0.58). Proteinuria cutoff, based on albuminuria cutoff of 30 mg/24 hours, was found to be 160.5 mg/24 hr. Body mass index (BMI) was the sole independent predictor of proteinuria above 160.5 mg/24 hr. Changes in albuminuria, but not proteinuria, were associated with changes in creatinine clearance. CONCLUSIONS: A new cutoff value of 160.5 mg/hr was set empirically, for the first time, for abnormal proteinuria in diabeticpatients. It appears that proteinuria below 300 mg/24 hr is not sufficient as a sole prognostic factor for kidney failure.