By Dr. Mark H. Shapiro
Disclaimer: This article is for informational purposes only and is not intended to be a substitute for medical advice or diagnosis from a physician.
Diabetes mellitus is a common condition, and in the United States is now the most frequent cause of kidney failure requiring dialysis. If you have diabetes and need dialysis, peritoneal dialysis (PD) may be a treatment option for you. First learn what diabetes is and how it relates to chronic kidney disease (CKD).
A person’s blood sugar (glucose) levels can be regulated by the actions of several hormones. Insulin is a hormone made by the pancreas that causes the removal of glucose from the blood stream. If a person doesn’t make enough insulin, or if the body becomes resistant to the effects of insulin, then that person develops diabetes mellitus.
Diabetes is a common condition that affects people of all ages and races. There are basically two types of diabetes. Type 1 diabetes is a condition in which the pancreas stops making insulin altogether, usually due to a virus that destroys the cells in the pancreas that make insulin. This condition most often begins during childhood. Type 2 diabetes occurs when the pancreas still makes insulin, but the body becomes resistant to its effects. Type 2 is the more common form of diabetes, and is often seen in people who are overweight.
Both Type 1 and Type 2 diabetes can cause damage to the kidneys, and this condition can lead to kidney failure. Chronic kidney disease tends to occur slowly over a period of years, and is first recognized by the appearance of large amounts of protein in the urine. Later the function of the kidneys begins to drop, as measured by rising levels of creatinine (a toxin in the blood that is cleared by the kidneys). Physical symptoms may include swelling of the ankles and numbness or burning in the feet. Dialysis may become necessary when the creatinine levels become excessively high and a person develops more severe symptoms, such as massive swelling, shortness of breath, nausea, loss of appetite and loss of energy.
There are a variety of things that your nephrologist may recommend to treat kidney disease due to diabetes. These treatments tend to slow down the loss of kidney function, but do not cure or eliminate the condition. For instance, a diet that limits salt and sometimes protein may be recommended. Careful control of blood sugar levels is important, and aggressive management to keep blood pressure below 125/70 is also often advised. Several types of medicines may be useful in slowing down the progression of kidney disease, including blood pressure drugs known as ACEIs (angiotensin converting enzyme inhibitors) and ARBs (angiotensin receptor blockers). Additional medicines are also needed to help manage problems associated with kidney disease, such as diuretics for fluid control, and either erythropoietin (EPO) or Aranesp® to treat the anemia that usually occurs in people with kidney disease. Your nephrologist will help manage these problems, and should be able to answer any questions you have about slowing down the progression of chronic kidney disease.
As kidney disease progresses, a person’s appetite usually falls and blood sugar levels frequently become lower. It is not unusual that a person with diabetes may need to reduce the dosing of diabetes medicines to prevent excessively low glucose levels.
Unfortunately, these interventions do not always prevent kidney failure, and approximately 40% of people on dialysis have diabetes as the cause. If a person with diabetes has kidney disease requiring dialysis, the very best option is to get a kidney transplant. However, since getting a transplant usually takes several years and not everyone is able to get one, most people will need to decide between hemodialysis and peritoneal dialysis (PD). In addition to the type of dialysis, a person will choose whether to have dialysis in a dialysis center or perform dialysis at home.
When choosing a type of dialysis, there are many factors to consider, but quality of life is often the most important one. People with diabetes mellitus can do very well on peritoneal dialysis. PD may allow a person to more easily travel, keep a job, raise a family or go to school. The benefits associated with dialyzing at home rather than in a clinic can be important to people who value freedom and independence. However, some people may not be able to do peritoneal dialysis due to vision problems, severe eating problems or previous multiple abdominal operations.
Since peritoneal dialysis uses sugar-based solutions (glucose) to perform dialysis, diabetics starting PD often will see a rise in their blood sugar levels. This is usually controlled by raising the dosage of diabetic medicines. Sugar levels are more easily managed when a person can avoid using PD fluid that has the highest levels of glucose (4.25%). This is best done by carefully controlling salt and fluid intake so that larger amounts of fluid do not have to be removed with the dialysis. Diet can also make a difference. Just like in diabetics without kidney disease, eating starches and sugary foods will cause a rise in blood sugar levels. Your renal dietitian can give you guidance about what to eat and how to better keep your sugar levels under control.
The type of dialysis solutions that you use can affect sugar levels. 1.5% dextrose (the yellow bags) will raise sugar levels the least, while 4.25% dextrose (the red bags) will raise sugar levels the most. In some cases, a non-glucose based dialysis solution called icodextrin (Extraneal) can be used. This solution may help prevent the rise of sugar levels, but can only be used for the dialysis long dwell. Diabetics who use Extraneal need to be certain that they are using the proper type of glucose test strips, since Extraneal can sometimes cause the sugar levels to appear higher than they really are. All patients on Extraneal need to review their diabetes test strips with their PD nurse, as some strips may show falsely elevated blood sugar levels.
Very high sugar levels (greater than 300 mg/dl) can occur in PD patients, but it is uncommon for this to cause symptoms. When symptoms do occur, the most common ones are dry mouth, blurry vision or increased urinary frequency. High blood sugar rarely requires hospitalization, and adjustments in medication therapy should be discussed with your doctor. Low blood sugars (less than 80 mg/dl) are relatively uncommon, but can cause symptoms. These include confusion, difficulty speaking or waking up, shakiness or hot flashes. Low sugar can be treated by eating or drinking sugary foods such as fruit juice, candy or a cookie. Some diabetic patients keep an injectable medicine at home called glucagon, which can be given by family members in the event that a low sugar level causes loss of consciousness. Frequent episodes of low sugar require a discussion about medicine changes with your physician.
Some diabetic medicines are normally eliminated from the body by the kidneys, and may require a reduction in dosage, or avoidance altogether:
These medicines may be given at standard doses to people with diabetes who are on peritoneal dialysis:
All forms of insulin can be used in peritoneal dialysis patients with diabetes. In general, more insulin is required during the day than at night, even in people who use nighttime cyclers. In most cases, a combination of long acting insulin (such as Lantus® or NPH insulin) with short acting insulin (such as lispro, Novolog® or regular insulin) works the best. Some people on PD who have diabetes may also do well on a combination of insulin and oral medicines. Insulin can also be added to some or all of the dialysate bags as another option for therapy.
Peritoneal dialysis is a reasonable option for a majority of people with chronic kidney disease who have diabetes. Proper monitoring and management will usually lead to acceptably controlled sugar levels with few complications.
Dr. Shapiro is a nephrologist who practices in Escondido, CA. He did his undergraduate training at University of California, Los Angeles, obtained his medical degree at the University of Pittsburgh, and completed his residency training and nephrology fellowship at the University of California, San Diego.
Dr. Shapiro is an Assistant Professor of Medicine at University of California, San Diego, but also maintains an active private nephrology practice in the San Diego area where he is president of Palomar Medical Group. His primary area of medical interest is in peritoneal dialysis (PD). Dr. Shapiro was a medical advisor for PD within Gambro Healthcare, Inc., and is now the National Peritoneal Physician Advisor to DaVita HealthCare Partners Inc. In addition, he serves on the Physician Advisory Council and the Pharmacy and Therapeutics Committee within DaVita.
Dr. Shapiro is married and has two sons. He enjoys kayaking, fishing and most other outdoor sports.
This site is for informational purposes only and is not intended to be a substitute for medical advice from a physician.
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