Diabetic nephropathy. Prevention and early referral.

OBJECTIVE To review the clinical and pathophysiologic features of diabetic nephropathy and to examine evidence supporting primary, secondary, and tertiary treatment strategies.

QUALITY OF EVIDENCE The medical literature provides both level 1 and level 2 evidence on treatment of diabetic nephropathy, including randomized controlled trials, well-designed clinical trials without randomization, consensus papers, and cohort and case-control analytic studies.

MAIN MESSAGE Diabetes is the most common cause of end-stage renal failure in Canada and the United States, and both diabetes and its renal complications are increasing. Diabetic nephropathy, in both type 1 and type 2 diabetes, usually progresses through five stages. Treatment and prevention strategies depend on stage of disease. Primary prevention includes addressing hyperglycemia, hypertension, and smoking. Secondary prevention adds angiotensin-converting enzyme inhibitors, cholesterol lowering, and perhaps restrictions on dietary protein. Tertiary care, including dialysis or transplantation, is generally managed by nephrologists, but family physicians continue to play an important role in the care of these patients.

CONCLUSIONS Diabetic nephropathy is a serious cause of morbidity and mortality for patients with type 1 and type 2 diabetes. To reduce end-stage diabetic nephropathy and its complications, both specialists and family physicians need to focus efforts on primary and secondary prevention strategies.