Pre-diabetes

What is pre-diabetes?
Pre-Diabetes can result from Insulin Resistance, which occurs when the body fails to use insulin properly or produces insufficient quantity in the pancreas. Insulin is vital for the process because it opens "doorways" on the cell's surface called insulin receptor sites, which allow glucose, or sugar, to pass through and be converted into energy. The number of these sites is highly reduced by Insulin Resistance and, as a result, levels of glucose and insulin in the blood stream raised and become severely unbalanced, which can lead to weight gain and obesity – underlying causes of Pre-Diabetes.

Who should be tested for pre-diabetes?
  • Adults' age greater than 18 years should undergo this test annually
  • Body mass index (BMI) ≥25 kg/m²
  • Hypertension
  • High density lipoprotein < 40 mg/dl in men or < 50 mg/dl in women.
  • Triglyceride (TG) > 150 mg/dl.
  • Women with a history of gestational diabetes.
  • Women with polycystic ovarian syndrome
  • (Hyper androgenic chronic anovulation).
  • A family history of type 2 diabetes.
  • If none of these risk factors exist, tests should begin at the age of 35, at a minimum every 3 years.
How to describe a pre-diabetic patient?
In pre-diabetes:
  • Blood glucose levels are higher than normal but not high enough to be characterized as diabetes. However, many people with pre-diabetes develop type 2 diabetes within 10 years.
  • Pre-diabetes also increases the risk of heart disease and stroke. With modest weight loss and moderate physical activity, people with pre-diabetes can delay or prevent type 2 diabetes.
  • Insulin Resistance and obesity are underlying causes of Pre-Diabetes, a reversible condition that occurs when a person's blood glucose levels are higher than normal but not high enough for a diagnosis of Type 2 Diabetes.

Before an individual develops Type 2 Diabetes, they are almost always Pre-Diabetic. The good news is that having Pre-Diabetes does not automatically mean that one will develop the Type 2 variety, which must be managed for the rest of a person's life and may require daily insulin injections. 
Research has shown that some long term damage to the body, especially the eyes, heart and circulatory system, may already be occurring during Pre-Diabetes.
Taking action to manage your blood glucose levels when you have Pre-Diabetes can prevent or delay Type 2 Diabetes from ever developing.

How are diabetes and pre-diabetes diagnosed?
Fasting Plasma Glucose (FPG) Test
The FPG is the preferred test for diagnosing diabetes due to convenience and is most reliable when done in the morning. Results and their meaning are shown in table 1. If the fasting glucose level is 100 to 125 mg/dl, the you have a form of pre-diabetes called impaired fasting glucose (IFG), meaning that you are more likely to develop type 2 diabetes but do not have it yet. A level of 126 mg/dL or above, confirmed by repeating the test on another day, means that you have diabetes

Table 1. Fasting Plasma Glucose Test

Plasma Glucose Result (mg/dL)

99 and below
100 to 125
126 and above

Diagnosis

Normal
Pre-diabetes (impaired fasting glucose)
Diabetes*

*Confirmed by repeating the test on a different day.

Oral Glucose Tolerance Test (OGTT)
Research has shown that the OGTT is more sensitive than the FPG test for diagnosing pre-diabetes, but it is less convenient to administer. The OGTT requires you to fast for at least 8 hours before the test. Your plasma glucose is measured immediately before and 2 hours after you drink a liquid containing 75 grams of glucose dissolved in water. Results and what they mean are shown in table 2. If your blood glucose level is between 140 and 199 mg/dL 2 hours after drinking the liquid, you have a form of pre-diabetes called impaired glucose tolerance or IGT, meaning that you are more likely to develop type 2 diabetes but do not have it yet. A 2-hour glucose level of 200 mg/dL or above, confirmed by repeating the test on another day, means that you have diabetes.

Table 2. Oral Glucose Tolerance Test

2 Hr Plasma Glucose Result

139 mg/dl  and below
140 mg/dl  to 199 mg/dl
200 mg/dl  and above

Diagnosis

Normal
Pre-diabetes (impaired glucose tolerance)
Diabetes*

*Confirmed by repeating the test on a different day.

Gestational diabetes is also diagnosed based on plasma glucose values measured during the OGTT. Blood glucose levels are checked four times during the test. If your blood glucose levels are above normal at least twice during the test, you have gestational diabetes. Table 3 shows the above-normal results for the OGTT for gestational diabetes.

Table 3. Gestational Diabetes: Above-Normal Results for the Oral Glucose Tolerance Test

When

Fasting
At 1 hour
At 2 hours
At 3 hours

Plasma Glucose Result (mg/dL)

95 or higher
180 or higher
155 or higher
140 or higher

Random Plasma Glucose Test

A random blood glucose level of 200 mg/dL or more, plus presence of the following symptoms, can mean that you have diabetes:
  • Increased urination
  • Increased thirst
  • Unexplained weight loss

Other symptoms include fatigue, blurred vision, increased hunger, and sores that do not heal. Your doctor will check your blood glucose level on another day using the FPG or the OGTT to confirm the diagnosis.
Positive test results should be confirmed by repeating the fasting plasma glucose test or the oral glucose tolerance test on a different day.

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