['To determine if nephropathy in NIDDM is associated with cellular markers for hypertension.', 'We compared 11 patients with clinical diabetic nephropathy with 15 control subjects with no diabetic nephropathy. The patients were white and had had NIDDM for > or = 9 yr and serum creatinine levels < or = 177 M (2.0 mg/dl).', 'Patients with nephropathy were more obese and had higher blood pressures and triglyceride levels, and lower high-density lipoprotein cholesterol levels than control subjects. Erythrocyte sodium lithium countertransport activity, erythrocyte sodium content, and platelet sodium-proton exchange were higher in patients with nephropathy than in control subjects.'] Is nephropathy in NIDDM associated with cellular markers for hypertension?