Unstable Diabetes

Unstable Diabetes

Also called: Brittle Diabetes, Labile Diabetes


Unstable or “brittle” diabetes is a term used to describe hard-to-control cases of diabetes in which glucose (blood sugar) levels swing unpredictably. At times the glucose tends to be too high (hyperglycemia), and other times it is too low (hypoglycemia).

Unstable diabetes usually refers to severe, uncontrolled forms of type 1 diabetes, but it can also describe poorly controlled cases of type 2 diabetes. It most often affects type 1 diabetes patients who are 15 to 30 years of age. However, the condition is also evident in elderly people with type 1 or type 2 diabetes.

Causes of unstable diabetes include many lifestyle factors that patients can change, including:

  • Poor diet
  • Lack of exercise
  • Stress
  • Problems with insulin administration
  • Not taking medications as directed
  • Not performing glucose monitoring as directed

Unstable diabetes can also occur when a person is unable to recognize problems with low glucose (hypoglycemia unawareness). Signs of unstable diabetes include periods of hypoglycemia or hyperglycemia, rapid changes in glucose or unpredictable morning glucose. These signs are sometimes severe enough to require hospitalization.

Unstable diabetes cannot be diagnosed with any single blood test. The condition, however, may be detected with tests that are used to evaluate how well a patient is managing diabetes over intervals of weeks or months.

Carefully adjusting insulin doses, frequently checking glucose and following a sick-day plan can help prevent diabetes from becoming unstable. Possible treatments include patient education, improved glucose meters, insulin pumps, new antidiabetic agents, a pancreas transplant or an islet cell transplant.

About unstable diabetes

The definition of unstable diabetes, also known as brittle diabetes, varies among medical professionals.  Some researchers reserve the term for a specific medical condition, but others use the term for general cases of poor diabetes management. Both definitions generally involve out-of-control diabetes that disrupts lives and causes repeated hospitalizations.

Variations of unstable diabetes include:

  • Hypoglycemic instability. Frequent and unpredictable low glucose levels (hypoglycemia) characterizes this type of condition. It can strike without the individual noting any warning signs.

  • Mixed hypoglycemic and hyperglycemic instability. The glucose (blood sugar) makes unpredictable swings between high and low levels.

  • Diabetic ketoacidosis. High blood glucose (hyperglycemia) and lack of insulin prompt the body to use fat tissue for energy. The resulting acidic wastes, ketones, damage the cells and can lead to diabetic coma.

  • Hyperosmolar hyperglycemic nonketotic syndrome (HHNS). Severe hyperglycemia and dehydration characterize HHNS. It can occur in people whose diabetes has not yet been diagnosed, and it can lead to diabetic coma.

Young people with type 1 diabetes appear most prone to unstable diabetes. The peak age group is 15 to 30 years old, but unstable diabetes is expected to grow among the elderly along with use of insulin.

In the past, uncontrolled or brittle diabetes was frequently used to refer to any case of type 1 diabetes. With advances in treatment of type 1 diabetes, the terms have become restricted to severe uncontrolled cases of type 1 or type 2 diabetes.

Potential causes of unstable diabetes

Metabolic causes of unstable diabetes are more common in older diabetes patients. Diabetic individuals with very little body fat or with kidney failure are prone to unstable (“brittle”) diabetes.

Unstable diabetes often has causes – and solutions – within the patient’s control. These factors include:

  • Noncompliance. This term is used when patients fail to follow thediabetes management plan outlined by their healthcare provider. Noncompliance may include missed insulin treatments, failure to monitor glucose (blood sugar) or other issues. Intensive diabetes education and family counseling are often necessary to help the patient follow the treatment plan and prevent complications.
  • Insulin injection issues. Two factors affect how fast injected insulin enters the bloodstream: the site of the injection and how deep the injection is made. Insulin enters the blood faster when injected into the abdomen than the limbs and from a deep rather than a shallow injection. Diabetes patients often adjust the injection site to avoid the scarring that can slow absorption of insulin. However, inconsistency with the site and depth of injections can play a role in unstable diabetes.

Research has shown that some patients take inadequate doses of insulin because they dislike syringe injections. Some people find insulin pens more comfortable and convenient, and an insulin pump or the recently approved inhaled insulin may be an option for some patients.

  • Poor diet. Starches, sugars and other quickly digested foods cause glucose levels to jump and then plunge. In addition, foods may change insulin absorption depending on a number of factors, such as time they are eaten and foods with which they are combined. Diabetes patients must monitor their reaction to certain foods if they notice a change in glucose levels.
  • Inactivity or inconsistent levels of activity. Physical activity generally lowers glucose, and regular activity can help to improve the body’s ability to use glucose efficiently. Inactivity or a sudden change in activity levels can contribute to problems with glucose management.
  • Stress. Emotional, psychological and physical stress can increase glucose levels.
  • Mental health issues. Several studies have found increased rates of depression in people with diabetes. Depression can impair motivation and reduce adherence to the treatment plan. In addition, there have been some clinical reports of diabetic patients, especially in adolescence, intentionally sabotaging their treatment because of eating disorders, suicidal feelings or disputes with parents over control issues.
  • Impaired thinking. Several studies have found cognitive dysfunction such as memory loss and dementia to occur more often and at an earlier age in people with diabetes, especially type 2 diabetes. Cognitive difficulties can lead to problems such as inadequate medication, failure to perform glucose monitoring, malnutrition and dehydration. However, exercise and improved glycemic control have been found to improve memory in people with diabetes.

Another potential cause of unstable diabetes is a metabolic problem called hypoglycemia unawareness. Patients with this disorder do not experience (or fail to recognize) the typical warning signs of low glucose (hypoglycemia), including hunger, sweating, weakness and headache.

Hypoglycemia unawareness can happen even in people who practice tight glucose control because the body becomes used to low glucose or because a condition called autonomic neuropathy damages the nerves that control the body’s involuntary functions. Someone who is unaware of low glucose does not recognize the need to take action to raise the glucose level.

Signs and symptoms of unstable diabetes

Signs and symptoms of unstable diabetes vary depending on whether it involves hypoglycemia, hyperglycemia or a combination of both. Indicators include:

  • Frequent episodes of hypoglycemia, characterized by:
    • Sweating
    • Shaking
    • Fatigue
    • Weakness
    • Dizzinessor fainting
    • Headache
    • Restlessness
    • Irritability
    • Rapid heartbeat (palpitation)
  • Frequent episodes of hyperglycemia, characterized by:
    • Excessive urination (polyuria), thirst (polydipsia) and hunger (polyphagia)
    • Blurred vision
    • Nausea
    • Drowsiness
  • Erratic changes in glucose.
  • The Somogyi effect. A hyperglycemic rebound after a period of low blood glucose.
  • Unpredictable glucose in the morning. Blood glucose may rise overnight, especially in type 1 diabetes. For more information, see Dawn Phenomenon.
  • Depression, eating disorders or other psychological issues.
  • Episodes of dehydration or malnutrition.
  • Hospitalizations required by any of the above.

Diagnosis methods for unstable diabetes

It is recommended that patients experiencing signs and symptoms of unstable diabetes immediately contact their physician. The physician will typically perform a physical examination and review the medical history. A blood test can help detect poorly controlled diabetes.

The glycohemoglobin test (GHb test) is a measure of average glucose (blood sugar) over three months. Blood samples are taken from a fingerprick or vein in the arm during routine medical appointments. The test measures how much hemoglobin in the blood has bonded (glycated) with the glucose.

Six percent is typically considered a normal result on a glycohemoglobin test. A target for many diabetes patients is 7 percent. Some university research has defined unstable diabetes as GHb of greater than 8 percent.

A physician may instead use the fructosamine test to diagnose unstable diabetes. This blood test is similar to the glycohemoglobin test but measures average glucose levels over a few weeks instead of months.

Because unstable diabetes is not a scientifically defined term, different physicians may use different guidelines for diagnosis. For example, a physician may diagnose it on the basis of a GHb of greater than 8 percent, along with other symptoms of the condition. Another physician may use another standard when describing diabetes as unstable.

Unstable diabetes also may be diagnosed by extreme results in other diabetes tests, such as ketone tests. These blood or urine tests check for wastes (ketones) produced when the body uses stored fat instead of glucose for energy. An abnormally high amount (over 80 milligrams per deciliter in a urine test) may indicate unstable or poorly controlled diabetes.

Unlike the GHb test, which is an average of blood glucose over several months, high ketone levels generally indicate that blood glucose levels are extremely high at the same time that testing is taking place.

Treatment and prevention of unstable diabetes

Most of the factors that cause unstable diabetes are within a patient’s control. The first step in treatment is better management of glucose (blood sugar). Methods may include:

  • Increased frequency of insulin dosage and glucose monitoring. Because hypoglycemia unawareness can strike without warning, it is important to follow a schedule of checking glucose before any symptoms appear. The Diabetes Control and Complications Trial compared the number of insulin shots per day and frequency of glucose monitoring in people with type 1 diabetes. Researchers found that participants who injected insulin at least three times daily (or used an insulin pump) and who often monitored glucose had better glycohemoglobin (GHb) levels than those who injected insulin once or twice daily and monitored glucose only once a day.

For patients who used insulin inadequately because they find injections uncomfortable or inconvenient, insulin pens may be less objectionable. In addition, the U.S. Food and Drug Administration (FDA) has approved inhaled insulin powder as a treatment for nonsmoking adults with type 1 or type 2 diabetes. Inhaled insulin may not be an option for some patients, such as those who are pregnant, have recently quit smoking or have lung disease. Patients must still monitor their glucose and may still need to inject some insulin.

  • Lifestyle changes. These include:
    • Proper diet. Diabetes patients need to be cautious with their food choices and meal schedules. Following their physician-directed meal plan is an important part of managing glucose. A registered dietitian or certified diabetes educator can help.
    • Exercise. Physical activity generally lowers glucose levels and improves the body’s ability to use glucose efficiently. However, results vary depending on duration, intensity and timing of the activity with food intake and insulin injections. A physician should be consulted before starting an exercise program.
    • Stress management. Individuals with diabetes need to be aware that periods of increased stress can affect their diabetes management. Physicians may advise changes to insulin use or other treatments during periods of stress. Long-term stress may be addressed with counseling or other general stress management techniques.
    • Avoiding herbs that alter glucose. People with diabetes, especially unstable diabetes, may be advised to avoid medicinal herbs and supplements that affect glucose levels and can interfere with medication. These may include ginseng, karela, chromium, fenugreek, bitter melon, garlic, ginger, devil’s claw, licorice and ma huang. Some physicians may approve such supplements in an individual’s treatment plan, but patients are advised not to use them on their own.
  • Creation of a sick-day plan. A physician can devise a program to help prevent illnesses from escalating to life-threatening complications.
  • Patient education and counseling. Sessions with a certified diabetes educator, with family involved as appropriate, may improve understanding of the disease and increase compliance. Diabetes support groups may also be beneficial. Psychological counseling or other treatments may be needed in cases where depression, eating disorders or other mental health issues are interfering with metabolic control. Patients with cognitive problems may need increased supervision by caregivers.
  • insulin pump. This small device continuously supplies insulin to the body through a small tube. Improvements have made insulin pumps a safe and effective treatment for unstable diabetes, according to the National Institutes of Health (NIH) and the FDA. Training and monitoring of pump use is important as adjustment of insulin doses can take weeks to achieve maintenance. Implantable insulin pumps are available overseas but are still restricted in the United States to research and clinical trials.
  • Improved glucose meters. The FDA has approved meters that provide continuous glucose monitoring, and in 2006 it approved an insulin pump that incorporates continuous glucose monitoring.
  • Antidiabetic agents. The FDA has approved an injected drug called pramlintide (Symlin) for people who have difficulty controlling their type 1 diabetes or insulin-dependent type 2 diabetes. It is the only drug other than insulin approved for treating type 1 diabetes. People with hypoglycemia unawareness or gastroparesis should not use pramlintide, according to the FDA.

Another possible option may be to get a diabetes assistance dog. Several organizations train dogs to sense dangerous changes in glucose and alert their diabetic owner. There have been accounts of these animals saving people from a diabetic coma. However, demand is reported to be far greater than the supply.

If these methods are not enough to bring glucose levels under control, more aggressive treatments may be considered, such as:

  • Islet cell transplant. The islets of Langerhans are clumps of cells in the pancreas. One type of these cells, called beta cells, makes insulin. In a minimally invasive, experimental procedure, beta cells from donor organs can be injected into patients with type 1 diabetes to help them produce insulin. Scientists are conducting a great deal of research into islet transplants and have reported many recent innovations. However, the NIH has concluded that, for now, the risks of this procedure outweigh the benefits for most patients because of side effects from the immunosuppressive drugs required after the procedure.
  • Pancreas transplant. Surgical insertion of a donor organ to replace a defective pancreas is the most aggressive and invasive way to treat unstable diabetes. Because of the risk posed by immunosuppressives, the American Diabetes Association recommends that pancreas transplants generally be limited to people who already need immune-suppressing drugs for a kidney transplant.

It is especially important to consult a physician about unstable diabetes because definitions vary and treatments are evolving. Often changes in habits will ease the condition. A physician will be able to provide details about diagnosis, tests, prevention and the risks and rewards of treatments.

Questions for your doctor on unstable diabetes

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following  questions about unstable diabetes:

  1. How do you define unstable diabetes?
  2. Do I have or am I at risk of unstable diabetes?
  3. What diagnostic tests might I need to undergo?
  4. What do my test results show?  What should be my GHb goal?
  5. What is causing my diabetes to be unstable?
  6. Which factors are in my control? Do I have hypoglycemia unawareness or other factors that are harder to contain?
  7. Do eating disorders, depression or other psychological issues play a role in my unstable diabetes?
  8. What complications can unstable diabetes cause for me?
  9. What are the treatment options for my unstable diabetes? How do diet and exercise factor in? What about changes in my insulin or other medication?
  10. Will you establish a sick-day plan for me?
  11. How often should I perform glucose monitoring? Should I perform ketone tests at home? How often should I see you for a physical exam, blood tests and other tests?
  12. Could inhaled insulin, an insulin pump, continuous glucose monitoring, a pancreas transplant or an islet cell transplant be options for me?
  13. How can I prevent my diabetes from becoming unstable?
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