Diagnosing Diabetes and the Problem of "Pre-diabetes"

What does it mean to have "pre-diabetes?"  Does such a condition really exist?

In order to best understand the concept of “pre-diabetes,” it is important to understand what diabetes is. 
 

Diabetes

Diabetes is a condition of abnormally high blood sugar (also called blood glucose), that could cause micro-vascular complications, such as blindness and kidney failure.  A diagnosis of diabetes is made when either the pancreas is not making insulin (Type 1 diabetes) or when the body’s cells have become resistant to insulin (Type 2 diabetes).

Insulin helps the body’s cells absorb glucose for energy.  When the pancreas (the organ in which insulin is made) is not making insulin, glucose cannot be absorbed into the body’s cells.
 

Glucose

Glucose, therefore, remains in the bloodstream at abnormally high levels.  This condition is referred to as Type 1 diabetes, and is usually the result of an immune system response which has injured the insulin-making cells of the pancreas.

Type 1 diabetes can be managed, with a combination of daily insulin injections, diet, and exercise, but it cannot be cured.

Type 2 diabetes is diagnosed when blood glucose levels are high even though the pancreas is making insulin.  With type 2 diabetes, the body becomes unable to use insulin well, as the body’s cells are unable to absorb glucose from the bloodstream efficiently.

When glucose cannot be absorbed by the cells, it remains in the bloodstream at elevated levels.  Elevated levels of blood glucose stimulate more insulin production in the pancreas, until, ultimately, the pancreas cannot make enough insulin.

Diabetes type 1 and type 2 are very different; the prevention and treatment of each type of diabetes is different.  With either type of diabetes, the treatment goal is to maintain normal levels of blood glucose in an attempt to avoid complications that result from chronically elevated levels of glucose, such as blindness, heart attack, stroke, kidney failure and foot problems (micro-vascular complications).

The diagnosis of “pre-diabetes” is, theoretically, a precursor to type 2 diabetes.  “Pre-diabetes” indicates a degree of insulin resistance.  In “pre-diabetes” blood glucose levels are not high enough to make a diagnosis of diabetes, but not low enough to be considered “normal.”

However, not everyone who is diagnosed with “pre-diabetes” will go on to develop type 2 diabetes, despite what the name implies.  Not everyone who is diagnosed with “pre-diabetes” will realize an increased risk of diabetes related micro-vascular complications.
 

Diagnosing Pre-diabetes and Diabetes

There are three different blood glucose measurements used to diagnosed diabetic conditions:

The fasting glucose level is perhaps the most accurate diagnostic test for diabetes.

• Normal fasting glucose is under 100mg/dL
• Pre-diabetes is diagnosed with a fasting glucose level of 100-125mg/dL
• Fasting glucose levels of 126mg/dL or higher are diagnostic for diabetes

The 2-hour glucose tolerance test evaluates the body’s response to 75mg of glucose, which is administered as a drink.  Two hours after the drink is consumed, blood glucose is tested.

• Normal 2-hour glucose tolerance is below 140mg/dL
• Pre-diabetes is diagnosed with a 2-hour glucose level of 140-199mg/dL.
• Diabetes is diagnosed with a 2-hour glucose level at or above 200mg/dL

Hemoglobin A1C (also known as HgbA1C, or glycosylated hemoglobin) can be measured without any special preparation.  Neither fasting nor a glucose load is required.

• Normal HgbA1C is 5.6% or under
• "Pre-diabetes" is diagnosed with a HgbA1C of 5.7%-6.4%
• Diabetes is diagnosed with a HgbA1C of 6.5% or higher

Hemoglobin A1C can be altered by various medical conditions, causing both over- and under- diagnosis of diabetes.  Though hemoglobin A1C has been used to diagnose “pre-diabetes,” there is no evidence to support that the above noted levels indicate any degree of insulin resistance.
 

What Are the Problems of “Pre-diabetes?”

There is not perfect agreement among health care professionals, professional organizations, or advocacy organizations such as the American Diabetes Association on how “pre-diabetes” should be defined, diagnosed, monitored or treated. 

Clarifying a definition of “pre-diabetes,” and the interpretation of the lab work in order to make a diagnosis of “pre-diabetes” are not the only concerns.

• Early intervention (lifestyle changes such as weight loss and exercise) has only been documented to reduce complications for individuals in highest risk groups (those with a “pre-diabetic” diagnosis and obesity and/or abnormal cholesterol).  It is well established that people who are obese and/or have abnormal cholesterol are at higher risk for developing diabetes.  The diagnosis of “pre-diabetes” does not add any predictive value.
• Some people who are diagnosed with “pre-diabetes” might not actually be at risk, but would potentially be treated regardless.
• If universally applied, so many people would be diagnosed with “pre-diabetes” that treating everyone who is “per-diabetic” would financially cripple the health care system, without any clear benefit for most individuals or the public health.
• Individuals could endure potential side effects of unnecessary or ineffective medication.
• The intent of treatment is not to cure diabetes so much as it is to prevent the micro-vascular complications of diabetes.  Treatment may lower glucose, but there is no evidence that normalizing glucose in “pre-diabetes” postpones or reduces the risks of micro-vascular complications.
• “Pre-diabetes” might be considered a preexisting condition for diabetes by health and/or life insurance companies, even though not everyone with “pre-diabetes” develops diabetes.
• The treatment for “pre-diabetes” is the same as the treatment for the early diagnosis of type 2 diabetes.

“Pre-diabetes” is likely a unique condition for some individuals, but may be too broad to warrant the concern it generates on a widespread basis.  Still, attention to the prevention of diabetes and diabetic complications is justified.
 

What To Do to Prevent Diabetic Conditions:

• Eat a healthy diet, full of fresh vegetables and fruits, whole grains and lean protein
• Avoid eating processed foods- foods made with white flour and white sugar
• Maintain a healthy weight
• Get adequate exercise (at least 150 minutes/week)

What To Do If You Are Diagnosed with “Pre-diabetes”?:

• Speak with your health care provider about what the diagnosis really means for you
• Monitor your condition and learn what you can do to prevent micro-vascular complications
• Make sure any recommended medication is right for you
• If you are overweight, aim to obtain- and maintain- a healthy weight
• If you have high cholesterol, make lifestyle choices that will help to lower it
• Exercise

If You Are Diagnosed with Diabetes (Type 2):

• Monitor your condition; keep your blood glucose under tight control
• If you are overweight, aim to obtain- and maintain- a healthy weight
• Exercise

Food, Health & You
Guest Author
Carina Ryder
Certified Nurse-Midwife with 20 years of clinical experience