Complications of Diabetes Mellitus: Kidney Disease

Diabetic kidney disease, if uncontrolled, can result in kidney failure and the need for dialysis or kidney transplantation. Persistently elevated blood pressure increases the risk, as do high blood sugar, cholesterol, and triglyceride levels.

Risk Factors

All individuals with diabetes are at risk for kidney disease. Pima Indians with type 2 diabetes have a particularly high risk of kidney disease and African-Americans with type 2 diabetes appear to have more than four times the risk of kidney failure, compared with Caucasians. This may also be true for Native Americans and Mexican-Americans.

Risk factors include:

• Family history of diabetic kidney disease
• Poor blood sugar control
• Hypertension
• Dietary factors (see Nutritional Considerations below)

Other possible risk factors include obesity, increasing age, duration of diabetes, and smoking.

Diagnosis

• The first steps are a medical history and a physical examination.
  
• Blood and urine testing will be performed.
  

Treatment

• Control of blood sugar is essential for preventing further kidney damage.
• If blood pressure is not controlled through diet and lifestyle changes (to below 130/80), treatment with ACE inhibitors (e.g., lisinopril) or/and angiotensin receptor blockers (e.g., losartan) helps prevent worsening of kidney damage. Calcium channel blockers or diuretics may be appropriate substitutes.
• Control of cholesterol and triglyceride levels is important.
• Weight loss is helpful, perhaps because of its beneficial effects on blood sugar, blood pressure, and cholesterol.

Nutritional Considerations

Reducing saturated fat, cholesterol, and animal protein intake may reduce the risk for kidney damage. Excessive intake of total protein and animal (not vegetable) protein has been shown to be a risk factor for abnormal kidney function. In short-term studies, vegetarian diets and diets deriving protein primarily from soy and other plant sources have improved kidney function. These diets also improve blood pressure control, which further helps reduce the risk for kidney damage. In addition, dietary sodium restriction is recommended.