Diabetes - Nephrology Overview
Diabetes and the Kidney
Diabetes mellitus (DM) is the leading cause of kidney failure in the United States. Approximately one-half of people who need dialysis have kidney disease from diabetes.
Defining diabetic kidney disease
Diabetic kidney disease is defined as abnormal urinary albumin excretion in a diabetic patient. Normal individuals usually excrete less than 30 mg of albumin daily. Those said to have microalbuminuria excrete 30 to 300 mg daily. An individual who excretes greater than 300 mg of albumin daily is said to have macroalbuminuria or clinical proteinuria. Typically, patients with diabetic kidney disease develop increasing proteinuria which precedes the loss of kidney function – i.e., a reduction of glomerular filtration rate (GFR).
The American Diabetes Association and the National Kidney Foundation recommend annual testing for protein in the urine (albumin/creatinine ratio) starting five years after diagnosis of Type I diabetes. People with Type II diabetes should be tested for albuminuria and estimates of GFR at the time of diagnosis. This is because many patients with Type II DM are not diagnosed until several years after they have blood sugar abnormalities.
Do both Type I and Type II diabetics get kidney disease?
Yes. Type I diabetes which is the type that people generally get at younger age, can cause kidney disease in about one-third of the affected people. We now know that Type II diabetics also have a similar rate of developing kidney disease. However, Type II diabetes is far more common, which makes it the leading cause of kidney failure.
Can diabetic patients reduce the chance of getting kidney disease?
Absolutely. Genetics or family history may influence the chance of getting diabetic kidney disease. If a diabetic has a family member with diabetes and kidney disease, they are at increased risk for diabetic kidney disease. They should be screened early and followed vigilantly. For all diabetic patients, the important thing is keeping diabetes under tight control. In a study of diabetics called the Diabetic Control and Complications Trial (DCCT), tight control of blood sugar reduced the risk of diabetic retinopathy, neuropathy, and kidney disease by nearly 50%.
What is the optimal treatment of patients with diabetic kidney disease?
In addition to tight control of blood sugar, several large randomized controlled trials have documented that therapy with ACE inhibitor drugs or angiotensin receptor blockers (ARB) can delay the appearance of diabetic nephropathy and slow the progression of this chronic kidney disease. Importantly, the “renal protective” of the ACE and ARB agents seem to be independent of whether or not the patient has hypertension.
Diabetic patients with hypertension have a special lower blood pressure target of less than 130/80 mmHg, and should be treated with such agents as ACE and ARB to reduce cardiovascular risk and delay progression of kidney disease.
We recommend that diabetic patients with kidney disease be referred to our CKD Clinic for a comprehensive management strategy. The CKD Clinic provides comprehensive medical care utilizing a team approach which includes a nephrologist, certified nurse practitioners, dedicated nursing staff, CKD educators, renal and diabetic dietitians, etc.
The goals of the CKD Clinic are three-fold:
- to delay the progression of diabetic kidney
- to reduce the morbidity and mortality of the diabetic kidney patient with an intensive cardiovascular risk management
- to optimize the transition to renal replacement therapy (RRT), such as dialysis, and kidney transplantation.
A consultation may be arranged with one of our nephrologists in the CKD Clinic by calling 216.444.6771 to make an appointment.