Prediabetes And Glucose Intolerance: Impaired Fasting Glycemia Vs Impaired Glucose Tolerance

Glucose intolerance — or prediabetes — is a condition in which patients have abnormally high levels of glucose, a type of sugar, in the blood. However, the blood sugar levels are not high enough to be considered diabetes. Patients with glucose intolerance or prediabetes are much more likely to develop type 2 diabetes, but the good news is that prediabetes is reversible if you make lifestyle modifications that involve exercising, eating healthier and losing weight.

There are two major sub-categories of glucose intolerance:

1. Impaired fasting glycemia, which develops when the blood glucose levels stay high during periods of fasting, but the levels are not high enough for a diagnosis of diabetes.
2. Impaired glucose tolerance, which means that your blood glucose levels are higher than normal but not high enough to reach a diagnosis of diabetes.

Impaired fasting glycemia

Symptoms of impaired fasting glycemia

There are not many symptoms that are indicative of impaired fasting glycemia and thus, a diagnosis can take a long time. Symptoms may include:

• Excessive thirst
• Excessive urination
• Recurrent infections
• Blurred vision
• Wounds or sores heal slowly

If you find yourself experiencing any of these symptoms, you may have impaired fasting glycemia and should go see a doctor immediately.

Risk factors for impaired fasting glycemia

Patients who are diagnosed with impaired fasting glycemia tend to be:

• Overweight
• Have high blood pressure
• High cholesterol levels
• Family history of Impaired fasting glycemia
• Black or South Asian and over the age of 25
• Caucasian and over the age of 40

They may also: 

• Have high blood pressure
• Have had a heart attack
• Have had a stroke
• Have had gestational diabetes, which occurs in pregnancy
• Have severe mental health problems

Diagnosis of impaired fasting glycemia

Impaired fasting glycemia is diagnosed first by testing your blood glucose levels. If they are between 3.6-6mmol/l, then your blood glucose levels are normal. If they are between 6.1-6.9mmols/l, then you may have impaired fasting glycemia.

Treatment for impaired fasting glycemia

Generally, you don’t need medical treatment for impaired fasting glycemia. However, it is important for you to lower your blood glucose levels by:

• Having a balanced diet
• Losing weight
• Exercising more
• Quitting smoking
• Limiting alcohol intake

Impaired glucose tolerance

Therefore, it is important to control your glucose levels so that you have a lower risk of developing these complications:

• High blood pressure
• High cholesterol levels
• Being obese
• Cardiovascular disease, such as heart attack

Definition of impaired glucose tolerance

The guidelines for what is defined as impaired glucose tolerance are set by the World Health Organization and are as follows: patients that have blood glucose levels between 7.8-11.1 mmol/L after undergoing a two-hour oral glucose tolerance test will be diagnosed with impaired glucose tolerance. An oral glucose tolerance test essentially tests how well your body is able to process or metabolize glucose.  

Risk factors associated with impaired glucose tolerance

Similar to impaired fasting glycemia, the risk factors that put patients at a higher risk of developing impaired glucose tolerance include:

• Being overweight or obese
• Having a family history of diabetes
• Leading a sedentary lifestyle
• Having high blood pressure
• Having high cholesterol
• Having had gestational diabetes

Symptoms of impaired glucose tolerance

Unfortunately, there are really no symptoms that are indicative of impaired glucose tolerance and many patients can have the disease without knowing it.

Treatment

Similar to Impaired fasting glycemia, treatment for impaired glucose tolerance includes:

• Losing weight
• Exercising more
• Having a heathy diet, which included have a low-carbohydrate and low-sugar diet
• Quitting smoking
• Limiting alcohol intake
• Taking care of your blood pressure
• Staying adherent to medications that your doctor may have prescribed.

Impaired fasting glycemia vs impaired glucose tolerance

The differences between patients with impaired fasting glycemia compared to patients with impaired glucose tolerance is largely based on risk of complication. These are:

• Patients with impaired fasting glycemia have a lower risk of developing type 2 diabetes compared to patients with impaired glucose tolerance.
• Patients with impaired fasting glycemia have a lower risk of developing cardiovascular disease compared to patients with impaired glucose tolerance.