In 734 patients with arterial hypertension without established diseases of cardiovascular system (including 158 patients with diabetes mellitus) we compared various methods of assessment of functional state of the kidney (microalbuminuria, creatinine, calculation of creatinine clearance and glomerular filtration rate) for detection of subclinical renal involvement and assessment of cardiovascular risk. We showed that determination of microalbuminuria and calculation of glomerular filtration rate (MDRD equation) had independent and mutual complementary diagnostic value, and allowed to identify patients with pathogenetically different renal lesions, reflected proteinuric and nonpoteinuric mechanisms of progression of nephropathy in arterial hypertension with and without diabetes mellitus.